CA2249057C - Infrared sensor - Google Patents
Infrared sensor Download PDFInfo
- Publication number
- CA2249057C CA2249057C CA002249057A CA2249057A CA2249057C CA 2249057 C CA2249057 C CA 2249057C CA 002249057 A CA002249057 A CA 002249057A CA 2249057 A CA2249057 A CA 2249057A CA 2249057 C CA2249057 C CA 2249057C
- Authority
- CA
- Canada
- Prior art keywords
- infrared
- detecting element
- container
- infrared detecting
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000000758 substrate Substances 0.000 claims abstract description 16
- 238000001514 detection method Methods 0.000 claims abstract description 15
- 239000000470 constituent Substances 0.000 claims description 12
- 239000000463 material Substances 0.000 claims description 7
- 230000008859 change Effects 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 238000012937 correction Methods 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 abstract description 5
- 239000003973 paint Substances 0.000 description 7
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 6
- 238000005530 etching Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 230000004907 flux Effects 0.000 description 4
- 239000010410 layer Substances 0.000 description 4
- WGTYBPLFGIVFAS-UHFFFAOYSA-M tetramethylammonium hydroxide Chemical compound [OH-].C[N+](C)(C)C WGTYBPLFGIVFAS-UHFFFAOYSA-M 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- 101100353161 Drosophila melanogaster prel gene Proteins 0.000 description 2
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- 230000020169 heat generation Effects 0.000 description 2
- 238000005304 joining Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 238000001020 plasma etching Methods 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 238000009877 rendering Methods 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 238000007790 scraping Methods 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- 101100234002 Drosophila melanogaster Shal gene Proteins 0.000 description 1
- 235000015076 Shorea robusta Nutrition 0.000 description 1
- 244000166071 Shorea robusta Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- ONRPGGOGHKMHDT-UHFFFAOYSA-N benzene-1,2-diol;ethane-1,2-diamine Chemical compound NCCN.OC1=CC=CC=C1O ONRPGGOGHKMHDT-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005422 blasting Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000007261 regionalization Effects 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 238000005488 sandblasting Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/06—Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity
- G01J5/061—Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity by controlling the temperature of the apparatus or parts thereof, e.g. using cooling means or thermostats
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/04—Casings
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/06—Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/06—Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity
- G01J5/064—Ambient temperature sensor; Housing temperature sensor; Constructional details thereof
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/06—Arrangements for eliminating effects of disturbing radiation; Arrangements for compensating changes in sensitivity
- G01J2005/066—Differential arrangement, i.e. sensitive/not sensitive
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/02—Constructional details
- G01J5/04—Casings
- G01J5/041—Mountings in enclosures or in a particular environment
- G01J5/045—Sealings; Vacuum enclosures; Encapsulated packages; Wafer bonding structures; Getter arrangements
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
- H01L2224/4805—Shape
- H01L2224/4809—Loop shape
- H01L2224/48091—Arched
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/30—Technical effects
- H01L2924/301—Electrical effects
- H01L2924/3025—Electromagnetic shielding
Abstract
An infrared sensor is formed with a first infrared detecting element for infrared detection disposed in a container through a supporting substrate, and a second infrared detecting element for temperature compensation also disposed in the container to be shielded by the supporting substrate of the first infrared detecting element from incident infrared within the container, while a temperature sensing section of the first infrared detecting element is born in non-contacting state with respect to a supporting part of the substrate for the element, whereby the sensitivity can be remarkably improved with a simpler arrangement while keeping a high precision and inexpensiveness.
Description
CA 022490~7 1998-09-29 INFRARED SENSOR
BACKGROUND OF THE INVENTION
This invention rel.ates to an infrared sensor for detecting infrared in response to thermal variation due to absorption of infrared.
DESCRIPTION OF RELATED ART
Infrared detecting el.ements for use in the infrared sensors have been genera]ly c]assified into quantum type and thermal type in accordance with operational principl.e. While the quantum type infrared detecting element is extremely high in the sensitivity, there have been such probl.ems due to the necessity of using lt at lower temperatures with the e]ement itse]f coo1ed that the sensor is difficu].t to hand]e, manufacturing costs become high, dimensions in a system including means for cooling the element become ].arger, and so on.
In contrast, the therma] type infrared detecting element is less sensitive than the quantum type but is not required to be cooled and simpler in the structure, and has been utilized widel.y in various practical. ways of use, because of such advantages as l.ow manufacturing costs, minimized dimensions and so on.
The infrared sensors of this type have been disclosed in Japanese Util.ity Model Laid-Open Publication No. 61-50232 by K. Kitamura et al., and U.S. Patent No.
4,258,260 by H. Obara et al..
In a typical arrangement of another known CA 022490~7 1998-09-29 thermal type sensor, a first infrared detecting e]ement for infrared detection and a second infrared detecting element for temperature compensation are concurrent]y disposed in a container comprising a cap and a stem, and an infrared shielding plate for preventing the incidence of infrared onto the second infrared detecting el.ement from occurring is provided at part of front face of an infrared transmitting fil.ter closing an incident window provided in the cap, or the infrared transmitting filter is provided onl.y at a position opposing the first infrared detecting element so that the infrared Wll 1 not be incident on the second infrared detecting element.
In the above sensor arrangement, however, there is present a space between the second infrared detecting element for the temperature compensation and the infrared shielding plate or the like so that, in order to compl.etely shield the infrared apt to be incident on the second infrared detecting element, it will. be necessary that an angle of view of the first infrared detecting el.ement is set, an aperture is provided for allowing the infrared only within the range of the set angle of view to be incident, and an infrared shielding section is provided to be sufficiently l.arger than the second infrared detecting element for completely shielding the infrared present outside the range of set ang]e of view. In this case, the incidence of infrared to the first infrared detecting element from a certain direction is caused to be hindered, so that there wil]. arise a problem that the CA 022490~7 1998-09-29 sensitivity may happen to be remarkabl.y varied depending on the direction of incidence of the infrared.
SUMMARY OF THE INVENTION
An object of the present invention is to overcome the foregoing problems and to provide an infrared sensor capable of restraining any deterioration in the detecting precision due to variation in the ambient temperature, only at lower costs required.
According to the present invention, the above object can be attained by means of an infrared sensor wherein first and second infrared detecting elements have respectivel.y a temperature sensing section provided for converting a temperature variation of the section due to incident infrared into an electric detection signal, and the temperature sensing section is disposed in a container having an infrared incident window for enl.arging the temperature variation, characterized in that the first infrared detecting element for infrared detection and the second infrared detecting element for temperature compensation are disposed in the conta1ner, the temperature sensing section of the first infrared detecting element is supported in non-contacting state with respect to a supporting part of a supporting substrate for the element, the first infrared detecting el.ement is supported by the supporting substrate in opposition to the infrared incident window, and the second infrared detecting element is shie]ded by the supporting substrate of the first infrared detecting element from the CA 022490~7 1998-09-29 infrared incident. With this arrangement of the infrared sensor, it is enabled to restrain any deterioration in the detecting precision of the infrared due to variation in the ambient temperature without causing any hindrance to the compensation for the ambient temperature nor any increase in the costs, while the second infrared detecting element for the temperature compensation is disposed in the same container as that of the first infrared detecting element.
Other objects and advantages of the present invention shall become cl.ear as the description of the invention advances as detailed with reference to preferred embodiments shown in accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE la shows in a pl.an view an infrared detecting element employed in the infrared sensor according to the present invention;
FIG. lb is a sectioned view of the el.ement of FIG. la taken along l.ine X-X;
FIGS. lc to le, FIGS. lf to lh, FIGS. li to lk and FIGS. ll. to lo are respective]y explanatory views for manufacturing steps in different aspects of the infrared detecting element employed in the present invention;
FIGS. 2 and 3 show in simil.ar plan and sectioned views in another aspect of the infrared detecting element employed in the sensor according to the present invention;
FIG. 4 shows one of circuit arrangements empl.oyable for the infrared sensor according to the CA 022490~7 1998-09-29 present invention;
FIG. 5 shows another exampl.e of the circuit arrangement employable in the present invention;
FIG. 6 shows in a schematic sectioned view an embodiment of the infrared sensor according to the present invention; and FIGS. 7-17 are schematic sectioned views showing other embodiments of the infrared sensor according to the present invention.
While the present invention shall. now be described with reference to the preferred embodiments shown in the drawings, it should be appreciated that the intention is not to ]imit the invention only to these aspects and embodiments shown but rather to incl.ude all alterations, modifications and equival.ent arrangements possible within the scope of appended c]aims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In an infrared detecting el.ement 1 employed in the present invention as shown in FIGS. la and lb, a fil.m section 4 consisting of a dielectric fil.m is constituted by forming the dielectric film on a supporting part 3 consisting, for example, of a Si substrate, and providing in the supporting part 3 a cavity or recess, and a temperature sensing section 5 for absorbing the infrared on the film section 4. Further, a microbridge structure is constituted by providing diaphragm parts or slits in the film section 4. Whil.e it is desirable fundamental.l.y that a second infrared detecting element for temperature CA 022490~7 1998-09-29 compensation is prepared in the same structure as that described above of the first infrared detecting el.ement 1 for the infrared detection so that both e]ements may be empl.oyed in an infrared sensor according to the present invention later described, they need not be a]ways the same. Further, the supporting part 3 needs not be limited to the Si substrate, and may be an alumina substrate or the 1ike.
The dielectric film is constituted by a fi]m of, for example, SiO, SiN, SiON or the l.ike, whereas the temperature sensing section 5 is of a structure in which such element for grasping temperature variation due to the incidence of infrared as thermistor, thermocouple, thermopile, pyroelectric element or SAW e]ement is provided with electrodes for outputting detection signa]s, and, as required, the dielectric fi]m of SiO, SiN, SiON or the ].ike is formed thereon. In attaining thereafter a bridging structure, in particular, the microbridge structure at a part of the film section 4 for supporting the temperature sensing section 5 as shown in FIG. 2, the part of the film is subjected to such etching as RIE
(reactive ion etching) process for allowing parts of supporting beams 6 of such diel.ectric fi]m as SiO, SiN, SiON or the like will be left, to form slits. In forming the supporting section in a diaphragm shape, the etching is carried out by means of a SiN-masking or the l.ike formed on the rear surface. In an event where the etching is to be carried out from surface side of the film section .. . .... . . ..
CA 022490~7 1998-09-29 4 to attain a formation of FIG. 3, further, a bored part is formed on lower side of the temperature sensing section 5 by etching the Si substrate 3 through the si].ts formed in the film section 4. As an etchant, various ones including KOH (potassium hydroxide), EDP (ethylenediamine pyrocatechol), hydrazine, TMAH (tetramethylammonium hydroxide) may be empl.oyed, whil.e an optimum one of them should be selected in accordance with such demanded conditions as protection of the temperature sensing section 5, the side from which the etching is made with respect to the film section 4, presence or absence of contact between the etchant and the surface of the temperature sensing section 5, and so on.
For an arrangement of non-contact support with respect to the supporting part 3, further, such aspects as foll.ows may be employed. As shown in FIGS. lc to le, for exampl.e, the supporting part 3 is mechanically scraped off as indicated by arrows, by means of a sandblasting or the like performed from a surface of the supporting part 3 opposite to the surface on which the temperature sensing section 5 is formed, while l.eaving the dielectric film section 4. In scraping off only a predetermined portion of the part 3, a pattern of resist or the l.ike may be used as a blasting mask, for easil.y carrying out such limited area scraping.
As shown in FIGS. lf to lh, further, a sacrificial l.ayer eventually removed is first made through a pattern formation on the supporting part 3 at part where CA 022490~7 1998-09-29 the temperature sensing section 5 is to be formed, the dielectric fil.m section 4 and sensing section 5 are then formed on the part 3 and sacrificial layer, and final.l.y the sacrificial. layer is removed. At this time, the sacrificial l.ayer may be removed by a etchant used through etching holes. For the material of the sacrificial layer, one which can be removed by an etchant not corrosive to the materials forming the temperature sensing section 5 and film section 4 may be used. Exampl.es of such materia]
will. be polysilicone, aluminum and the l.ike. Further, as shown in FIGS. li to lk, the arrangement may al.so be realized by forming the temperature sensing section 5 and dielectric film section 4 on another substrate 3', joining the substrate 3' and the sections 4 and 5 onto the supporting part 3 with the sensing section 5 positioned within a recess preliminarily made in joining surface of the supporting part 3, and final.]y removing the another substrate 3'. It is also possible to realize the arrangement as shown in FIGS. 1] to lo, wherein the recess prel.iminarily made in the supporting part 3 is first filled with an eventually-removed sacrificia] materia], the diel.ectric film section 4 and temperature sensing section 5 are formed on this supporting part 3 with the section 5 disposed above the sacrificial material, and finally the sacrificial material is removed.
In the first and second infrared detecting elements 1 and 2 of the same structure (see also FIG. 4), the temperature sensing section 5 employs an a-SiC
... . . ..
CA 022490~7 1998-09-29 (amorphous-sil.icon carbide) thermistor formed in a so-called sandwich structure as hel.d between a pair of electrodes consisting of Cr and of a thickness of about 1500 A. This temperature sensing section 5 is formed in a square shape of, for example, 500 ~m at one side, and each support beam 6 of the microbridge structure is made to have a width of 50 ~m.
Now, the measurement of temperature variation is enabled by, as shown in FIG. 4, connecting the respective temperature sensing sections 5 of the first and second infrared detecting elements 1 and 2 in series, applying to them a predetermined voltage V, and measuring variation in the potential Vout at junction point between them. As shown in FIG. 5, further, it may be a]so possible to connect a series circuit of externally fixed resistors R1 and R2 in parallel to the series circuit of the elements 1 and 2.
In FIG. 6, there is shown an embodiment of the infrared sensor according to the present invention, in which sensor the first infrared detecting element 1 for the infrared detection and the second infrared detecting element 2 for the temperature compensation are respectively of such structure as shown, for example, in FIG. 3. These first and second infrared detecting elements 1 and 2 are respectively die-bonded to each of printed wiring boards 131 and 132 on which wire-bonding wires are formed, the boards forming the supporting part 3, and the elements 1 and 2 are connected through wires 14 .
CA 022490~7 1998-09-29 to the respective wires on the printed wiring boards 13 and 132.
On the other hand, a container comprises a general.l.y cyl,indrical cap 10 and a stem 11 secured as wel,ded or the l.ike to an axial. end opening of the cap 10 to close the same, whereas the other axial end of the cap 10 is provided with an incident window 10a which is closed by an infrared transmitting filter 15. Pins 12 acting as electrodes are fixed to the stem 11 as passed therethrough, and these pins 12 are inserted into through holes (not shown) formed in the printed wiring boards 131 and 132 and are fixed thereto as adhered to the boards through conductive paste 17 for electric conduction. The printed wiring board 132 on which the second infrared detecting element 2 is mounted is disposed on l.ower side (the side of the stem 11) within the container, and ceramic-made spacers 16 are fitted over the pins 12 for keeping a predetermined space between the two printed wiring boards 131 and 132. Further, the printed wiring board 131 on which the first infrared detecting element 1 is mounted is disposed on upper side (the side of the incident window 10a) within the container. The pins 12 have flanges 12a of a larger diameter than the through hole in the printed wiring board 132 50 that the board can be positioned at a predetermined height from the stem 11.
Further, the respective printed wiring boards 131 and 132 are fixed to the pins 12 with their mounting surfaces of the infrared detecting el.ements 1 and 2 CA 022490~7 1998-09-29 disposed on the upper side. By disposing thus the element mounting surfaces of the respective printed wiring boards 131 and 132 on the same side, it is made possible to prevent the first and second infrared detecting elements from being damaged upon fixing the pins 12 to the printed wiring board 131 and 132.
Accordingly, in the present embodiment, the disposition of the printed wiring board 131 carrying the first infrared detecting element 1 for the infrared detection on the upper side of the second infrared detecting element 2 causes the infrared incident from the exterior into the incident window lOa through the infrared transmitting filter 15 (which shal.l be referred to as "incident infrared" in the foll.owings) to be incident upon the first infrared detecting el.ement 1 onl.y but to be prevented from reaching the second infrared detecting element 2 as shielded by the printed wiring board 131, and the second infrared detecting element 2 for the temperature compensation can be prevented from being influenced by the incident infrared. It is also enabled to utilize the printed wiring board 131 carrying the first infrared detecting element 1 concurrently as means for shielding the infrared with respect to the second infrared detecting element 2, whereby it is made unnecessary to separatel.y provide such means as the known infrared shielding plate, and any restriction of the angle of view of the first infrared detecting element 1 as well as any remarkable change in the sensitivity according to the CA 022490~7 1998-09-29 angle of view can be el.iminated from occurring. As a result, it should be appreciated that, in cooperation with the disposition of the second infrared detecting element 2 for the temperature compensation in the same container as the first infrared detecting element, any deterioration in the detecting precision due to the variation in the ambient temperature can be prevented at ]ow costs, without any hindrance to the compensation for the ambient temperature.
10Instead of the mounting of the second infrared detecting element 2 for the temperature compensation to the printed wiring board 132, the particular el.ement may be die-bonded directl.y to the stem 11 forming the container, as shown in FIG. 7, in which event the printed 15wiring board 132 as well as the spacers 16 may be made unnecessary, and the manufacturing costs can be further reduced.
Another embodiment of the present invention is shown in FIG. 8, in which the same basic constituents as those in FIG. 6 are denoted by the same reference numerals with their description omitted and on]y characteristic points shall be described in the followings.
In the present embodiment, the second printed wiring board 132 carrying the second infrared detecting element 2 for the temperature compensation is fixed to the pins 12 with the surface carrying the el.ement faced to the lower stem side, while the first printed wiring board 131 carrying the first infrared detecting element 1 for the CA 022490~7 1998-09-29 infrared detection is placed intimately on the second board with the surface carrying the first element faced to the incident window lOa both boards are disposed substantially in the center of the container so that a gap Ll between the first infrared detecting el.ement 1 and the infrared transmitting filter 15 and a gap L2 between the second infrared detecting element 2 and the stem 11 wi].l be substantially equal to each other (Ll L2) and a l.ayer of a l.ower refl.ectance material. such as a black paint than the material of the cap 10 and stem 11 is provided on inner walls of the cap 10 and stem 11 in order to prevent the incident infrared from reaching the second infrared detecting element 2 as refl.ected on the inner wa]ls.
Since other infrared than that incident through the incident window lOa is also incident on the first infrared detecting element 1 due to radiation or the like from the cap 10 and stem 11 of the container the disposition of the second infrared detecting element to face the innermost wal] of the container for rendering the other infrared due to the radiation or the like form the container to be incident also on the element 2 with the same intensity al.lows the intensity of the other infrared incident on both infrared detecting el.ements 1 and 2 than the incident infrared from the incident window lOa to be substantial.ly equal whereby any infl.uence due to the infrared received from the inner wal]s of the container can be compensated for and the detecting precision can be prevented from being deteriorated by the ambient .. . ... .... . . .. .
CA 022490~7 1998-09-29 temperature change.
In the present embodiment, further, the temperature sensing section 5 in each of the first and second infrared detecting elements 1 and 2 is constituted by a thermistor which causes a temperature variation to occur with its own heat generation, but a driving of the temperature sensing section 5 with a constant voltage or current is so performed that the own heat release val.ue wil1 vary in response to variation in the resistance val.ue of the thermistor due to the variation in the ambient temperature. To this own heat release value, the heat conductance relying on heat insul.ating structure of the infrared detecting elements 1 and 2 is determinative, and this heat conductance is determined by a sum of the heat conductance of the supporting diaphragm or microbridge for the temperature sensing section 5 and the heat conductance of ambient gas. Here, the heat conductance of the ambient gas is l.argel.y influenced by the gap L1 between the first infrared detecting el.ement 1 and the fi]ter 15 and the gap L2 between the second infrared detecting el.ement 2 and the stem 11, and any difference between these gaps causes a difference to arise in the heat conductance, whereby a difference is caused to arise in the own heat release value to render a heat difference to occur in the temperature sensing section 5.
At this time, in the present instance, the heat conductance can be made substantiall.y equal with respect to both temperature sensing sections 5 of the first and CA 022490~7 1998-09-29 second infrared detecting elements 1 and 2 by substantially equalizing both gaps Ll and L2, and the detecting precision can be prevented from being deteriorated due to the change in ambient temperature by rendering any temperature rise due to the own heat generation at the temperature sensing sections 5 to be in conformity to each other. Further, because of these respects, it is enabled to realize an infrared sensor further higher in the detecting precision than the embodiment of FIG. 6.
Further, because of the provision of the l.ayer of lower reflectance than the cap 10 and stem 11 by the application of black paint on the inner wall.s of the container, it is enabled to prevent the infrared reflecting on the inner walls of the container even in the case of wide angle of view, to prevent unnecessary infrared from being incident on the second infrared detecting element 2 for the temperature compensation, and, consequently, to realize an infrared sensor of a wide angle of view.
In another embodiment shown in FIG. 9 of the present invention, the first and second infrared detecting elements 1 and 2 are respectively mounted onto each of both surfaces of a single printed wiring board 18 having the printed wirings on the both surfaces, whil.e the second infrared detecting el.ement 2 is die-bonded to a recess 18a formed in the surface facing the stem 11 and the board 18 is brought into contact at least at peripheral edges with . .
CA 022490~7 1998-09-29 the inner walls of the cap 10.
By mounting in this way the first and second infrared detecting elements 1 and 2 respective]y onto each of front and rear surfaces of the single printed wiring board, it is enabled to reduce the manufacturing costs by the fact that only one printed wiring board 18 is required for mounting the two elements 1 and 2, and that required mounting work is simp]ified. It is also possible to render the recess 18a made in the printed wiring board 18 to have a depth enough for keeping the second infrared detecting element 2 in the recess 18a as we]l as the wires 14 not to project out of the rear, mounting surface of the board 18, whereby, when the mounting is made first for the second infrared detecting element 2 in the recess 18a on the rear surface and thereafter for the first infrared detecting element 1 onto the other front surface of the board 18, the second infrared detecting element 2 mounted initial can be prevented from being damaged by any jig or the like that may hit the element 2 upon mounting later the first infrared detecting element 1.
Further, since the printed wiring board 18 is brought into contact at the peripheral edges with the inner walls of the cap 10 of the container, the board 18 is improved in the ability of follow-up to the ambient temperature, the first and second infrared detecting elements 1 and 2 are made thereby to well follow the ambient temperature, and the detecting precision can be improved by achieving the temperature compensation with CA 022490~7 1998-09-29 the ambient temperature precisely monitored.
In the present embodiment, further, a gas communicating hole 18b is made as passed through the printed wiring board 18, and Xe gas of a l.ow heat conduction is seal.ed in the container. In substituting the low heat conduction gas for air inside the container for improving the sensitivity or in sealing the interior of the container by drawing a vacuum, therefore, it is made easier to discharge the gas in a space partitioned by the printed wiring board 18 on upper side thereof through the gas communicating hol.e 18b made in the board 18, and there arises an advantage that an improvement in the productlvity as well. as a reduction in the manufacturing costs can be attained.
In the embodiment of FIG. 9, other constituents are the same as those in the embodiment of FIG. 6 and are denoted by the same reference numera].s as those used in FIG. 6.
In FIG. 10, another embodiment according to the present invention is shown, in which the stem 11 of the container is molded integral with the pins 12 passed through the stem, and the short cylindrical cap 10 made of a metal, for example, is fitted over one front surface of the stem to be closed by the latter at one end opening, to define the space between them. The other end opening is closed by the infrared transmitting filter 15.
Within the space and on top ends of the pins 12 erected from the stem 11, the printed wiring board 13 is .......... . .
CA 022490~7 1998-09-29 secured, and the infrared detecting element 1 and a thermistor 7 as a contact type temperature sensor for measuring the temperature of the element 1 are mounted on the board 13. Here, the pins 12 may be provided to act also as output terminals for signal.s of the element 1 and thermistor 7. Further, the cap 10 defining the interior space in conjunction with the stem 11 is provided on the inner surfaces with thin heat radiating fins lOc.
With the provision of the heat radiating fins lOc, further, the time constant at which the temperature of the cap 10 coincides with the temperature of the interior space defined by the cap 10 and stem 11 can be made smaller, the temperature of the infrared detecting element 1, thermistor 7 as a temperature detecting means, cap 10 and stem 11 can be quickly stabi]ized even in the circumstances where the ambient temperature is apt to vary, and the temperature can be measured at a high precision. Further, with the temperature of the infrared detecting element thus enabl.ed to be measured by means of the thermister, it is made possible to correct any error in output signals occurring due to the ambient temperature variation, and the detecting precision can be further elevated.
Since the infrared detecting element 1 and thermistor 7 in the foregoing embodiments of FIGS. 9 and 10 are mounted on the single printed wiring board 13, further, they vary at the same temperature gradient, so as to be able to elevate the detecting precision even in a CA 022490~7 1998-09-29 state where the variation in the ambient temperature occurs.
In another embodiment shown in FIG. 11 of the present invention, the cap 10 in the embodiment of FIG. 10 is replaced by a cap lOA made with two metal members joined to be a double structure having an interior gap lOa filled with air.
While in the present embodiment the interior of the cap lOA is made to be the air layer lOa, the same is not required to be limited thereto but the interior may be fil.led with other gas or may even be drawn a vacuum.
Normally, the cap lOA and stem 11 are different in the heat capacity due to the difference in the thickness so that, in an event of variation in the ambient temperature, the temperature variation is apt to occur initially on the side of the cap lOA, but the present embodiment employing the cap lOA of the double structure having in the interior the air l.ayer lOa is capable of moderating the temperature fl.uctuation in the inner wall surface of the cap lOA, so that the infrared fl.ux from the inner wall. surface of the cap lOA and stem 11 to the infrared detecting elements 1 and 2 will. be substantial]y identical, and the detecting precision can be improved.
Further, as the temperature fluctuation in the space defined by the cap lOA and stem 11 can be moderated, the temperature fluctuation at the infrared detecting el.ements 1 and 2 and thermistor 7 can be also moderated, so that any difference in the temperature between these el.ements . . .
CA 022490~7 1998-09-29 can be minimized to render the detecting precision more excellent.
In the embodiment of FIG. 11, on the other hand, it is also possible to emp]oy a vacuum pressure arrangement with the interior space of the cap 10 and stem 11 drawn a vacuum preferably to be bel.ow 1 Pa. In this case, the thermal. conduction from the cap 10 and stem 11 to the infrared detecting elements 1 and 2 and thermister 7 is remarkably reduced even upon change in the ambient temperature, so as to relieve the temperature fluctuation, accordingly any temperature difference is l.ess caused to occur between these constituents, and the detecting precision can be further improved.
Other constituents of this embodiment are the same as those in the embodiment of FIG. 10, and the same constituents as those shown in FIG. 10 are denoted in FIG.
11 by the same reference numerals as used in FIG. 10.
In another embodiment shown in FIG. 12 of the present invention, the container is constituted simil.arly with the stem 11 molded integrally with the pins 12, and the short cylindrical cap 10 a bottom end opening of which is closed by the stem 11 to define an interior space, while the top end of the cap 10 is formed to have the incident window closed by the infrared transmitting fil.ter 15.
Within the interior space defined by the cap 10 and stem 11, the infrared detecting element 1 and the thermistor 7 as the contacting type temperature detecting CA 022490~7 1998-09-29 element for measuring the temperature of the infrared detecting element 1 are mounted on the stem 11, and the pins 12 are also acting as the signa]. output terminals of the element 1 and thermistor 7.
As a distinguishing feature here, the cap 10 and stem 11 are formed to have substantia]]y the same thickness.
In the present embodiment, therefore, the cap 10 and stem 11 can be made to have an identical. or the same level of the heat capacity by the same thickness, so that there arises no uneven temperature variation as the same temperature variation takes pl.ace in the cap 10 and stem 11 even upon variation in the ambient temperature, the infrared flux from the inner wall. surface of the cap 10 and stem 11 to the respective infrared detecting elements 1 and 2 can be made substantially identical., and the detecting precision can be improved.
In another embodiment shown in FIG. 13, in contrast to the embodiment of FIG. 10, such paint lOb of which the radiant emissivity is prel.iminarily known as the black paint is applied to parts of the inner wal.l.s of the cap 10 and stem 11 which are included in the ang]e of view of the infrared detecting el.ements 1 and 2. In the present instance, the infrared radiant emissivity is made constant on the inner surface of the cap 10 and stem 11 included in the angl.e of view of both elements 1 and 2, the infrared flux from the inner surface to the elements 1 and 2 will. be made substantially identical., and the CA 022490~7 1998-09-29 detecting precision can be improved.
In the embodiment of FIG. 13, further, the paint 10b may be rep].aced by a use or exec~tion of a mater1a]
for the whole or for surface layer or of a surface treatment with respect to the cap 10 and stem 11 and attaining the same effect as the paint 10b.
Other constituents of the present embodiment are the same as those in the embodiment of FIG. 10, and the same constituents are denoted in FIG. 13 by the same reference numerals as those in FIG. 10.
As another embodiment, the bl.ack paint 10b in FIG. 13 is replaced by a pl.ating of metal or the like to attain a lower radiant emissivity. In this case, the lower radiant emissivity at the inner walls of the cap 10 and stem 11 at least at portions included in the angle of view of the infrared detecting elements 1 and 2 renders the infrared flux from the inner wal]s of the cap 10 and stem 11 to the elements 1 and 2 to be smal.l enough to be substantial.l.y the same even when a temperature difference arises between the cap 10 and the stem 11 due to any variation in the ambient temperature, and the detecting precision can be improved. In this case, it is al.so preferabl.e to attain a mirror finish at the surface of the cap 10 and stem 11.
In another embodiment of the present invention as shown in FIG. 14, a further thermistor 9 is provided as adhered to an inner wall of the cap 10, in contrast to the embodiment of FIG. 10. In this case, it is made possibl.e CA 022490~7 1998-09-29 to predict an extent of variation in the output of the infrared detecting el.ement 1 due to the temperature variation of the cap 10, by measuring the temperature of the cap 10 by means of the thermistor 9.
Other constituents of thls embodiment are the same as those in the embodiment of FIG. 10, and the same constituents are denoted in FIG. 14 by the same reference numerals as those in FIG. 10.
In still another embodiment of the present invention as shown in FIG. 15, there are provided a plurality of the thermistors 7 for detecting the temperature at respective portions of the cap 10, stem 11, infrared transmitting fi].ter 15, infrared detecting element 1 and printed wiring board 13.
The calorie which is detected by the infrared detecting element 1 can be represented by a formula ~a-~a(Ta -Ts4) ................. (1) wherein ~a is the ratio of the angl.e of view at the incident window of the cap 10, ~a is the radiant emissivity of an objective, Ta is the temperature of the objective, and TS is the temperature of the infrared detecting element 1.
In an event where the ambient temperature is stable and the temperature at portions of the package within the angle of view of the infrared detecting element 1 (at the cap 10, stem 11 and infrared transmitting filter 15) coincides with the temperature of the infrared detecting element 1, the relation of incident infrared CA 022490~7 1998-09-29 flux at the infrared detecting element to the e]ement temperature and to the objective temperature can be obtained with the above formula (1), whereas, as the ambient temperature varies to render the temperature at the package portions in the angle of view of the element 1 to be different from the temperature of the element 1, then the infrared from the package is caused to be detected in addition to the infrared from the objective, and there occurs an error.
Here, the temperature correction factor at the package portions can be represented by a formula (T14-Ts4)+~2~2(T24-Ts )+ ~-- +~n- n( n s ..... (2) wherein ~n denotes the ratio of the angle of view at the package portions n, ~n denotes the radiant emissivity at the package portions n, and Tn denotes the temperature at the package portions n.
Now, by applying the output from the thermistors 7 to the above formula (2) and obtaining the sum or difference of the formulas (1) and (2), it is made possible to improve the detecting precision.
In another embodiment of the present invention as shown in FIG. 16, there is a difference from the embodiment of FIG. 10 in that, instead of the separate provision of the thermistor 7 as the temperature detecting means, the temperature of the temperature sensing section itself of one or both of the infrared detecting elements 1 and 2 is measured, for the correction of the detected CA 022490~7 1998-09-29 signals with the thus measured temperature value. More specifically, the temperature sensing section of these infrared detecting elements is constituted by the thermistor, and the temperature of the temperature sensing section is measured by obtaining the resistance value of the thermistor. While in the foregoing formu].a (1) the temperature Ts is denoted as that of the infrared detecting element, the infrared from the objective is to be received at the temperature sensing section in practice, and the temperature TS should be denoted inherently as that of the temperature sensing section of the infrared detecting element. When the general.
temperature variation is small., on the other hand, there arises no remarkabl.e temperature difference between the temperature sensing section and the separately provided temperature detecting means, and the temperature T may be denoted as the temperature of the infrared detecting element.
Here, in the case where the temperature difference is apt to occur between the respective parts in such event that the temperature at the respective parts of the sensor is varying due to the variation in the ambient temperature, there occurs the temperature difference between the temperature sensing section and the temperature detecting means, and it wil.l. be required, for accurate detection, to measure the temperature of the temperature sensing section in the infrared detecting el.ement. Since in the present embodiment the temperature CA 022490~7 1998-09-29 of the temperature sensing section itself is measured the detection is enabled at a higher precision.
In the present invention various design modification is possible within the scope of appended claims. In the embodiment of FIG. 14 for example the thermistor 9 provided on the inner surface of the cap 10 may be omitted as shown in FIG. 17 to employ only the single thermistor 7 mounted on the supporting substrate 13 along with the first infrared detecting element 1 for simplifying the arrangement in adaption to the use.
Further it should be appreciated that the embodiments of FIGS. 10 through 17 are respectively capable of mutual~y incorporating their characteristic arrangement of another embodiment.
, .. .. . . . .
BACKGROUND OF THE INVENTION
This invention rel.ates to an infrared sensor for detecting infrared in response to thermal variation due to absorption of infrared.
DESCRIPTION OF RELATED ART
Infrared detecting el.ements for use in the infrared sensors have been genera]ly c]assified into quantum type and thermal type in accordance with operational principl.e. While the quantum type infrared detecting element is extremely high in the sensitivity, there have been such probl.ems due to the necessity of using lt at lower temperatures with the e]ement itse]f coo1ed that the sensor is difficu].t to hand]e, manufacturing costs become high, dimensions in a system including means for cooling the element become ].arger, and so on.
In contrast, the therma] type infrared detecting element is less sensitive than the quantum type but is not required to be cooled and simpler in the structure, and has been utilized widel.y in various practical. ways of use, because of such advantages as l.ow manufacturing costs, minimized dimensions and so on.
The infrared sensors of this type have been disclosed in Japanese Util.ity Model Laid-Open Publication No. 61-50232 by K. Kitamura et al., and U.S. Patent No.
4,258,260 by H. Obara et al..
In a typical arrangement of another known CA 022490~7 1998-09-29 thermal type sensor, a first infrared detecting e]ement for infrared detection and a second infrared detecting element for temperature compensation are concurrent]y disposed in a container comprising a cap and a stem, and an infrared shielding plate for preventing the incidence of infrared onto the second infrared detecting el.ement from occurring is provided at part of front face of an infrared transmitting fil.ter closing an incident window provided in the cap, or the infrared transmitting filter is provided onl.y at a position opposing the first infrared detecting element so that the infrared Wll 1 not be incident on the second infrared detecting element.
In the above sensor arrangement, however, there is present a space between the second infrared detecting element for the temperature compensation and the infrared shielding plate or the like so that, in order to compl.etely shield the infrared apt to be incident on the second infrared detecting element, it will. be necessary that an angle of view of the first infrared detecting el.ement is set, an aperture is provided for allowing the infrared only within the range of the set angle of view to be incident, and an infrared shielding section is provided to be sufficiently l.arger than the second infrared detecting element for completely shielding the infrared present outside the range of set ang]e of view. In this case, the incidence of infrared to the first infrared detecting element from a certain direction is caused to be hindered, so that there wil]. arise a problem that the CA 022490~7 1998-09-29 sensitivity may happen to be remarkabl.y varied depending on the direction of incidence of the infrared.
SUMMARY OF THE INVENTION
An object of the present invention is to overcome the foregoing problems and to provide an infrared sensor capable of restraining any deterioration in the detecting precision due to variation in the ambient temperature, only at lower costs required.
According to the present invention, the above object can be attained by means of an infrared sensor wherein first and second infrared detecting elements have respectivel.y a temperature sensing section provided for converting a temperature variation of the section due to incident infrared into an electric detection signal, and the temperature sensing section is disposed in a container having an infrared incident window for enl.arging the temperature variation, characterized in that the first infrared detecting element for infrared detection and the second infrared detecting element for temperature compensation are disposed in the conta1ner, the temperature sensing section of the first infrared detecting element is supported in non-contacting state with respect to a supporting part of a supporting substrate for the element, the first infrared detecting el.ement is supported by the supporting substrate in opposition to the infrared incident window, and the second infrared detecting element is shie]ded by the supporting substrate of the first infrared detecting element from the CA 022490~7 1998-09-29 infrared incident. With this arrangement of the infrared sensor, it is enabled to restrain any deterioration in the detecting precision of the infrared due to variation in the ambient temperature without causing any hindrance to the compensation for the ambient temperature nor any increase in the costs, while the second infrared detecting element for the temperature compensation is disposed in the same container as that of the first infrared detecting element.
Other objects and advantages of the present invention shall become cl.ear as the description of the invention advances as detailed with reference to preferred embodiments shown in accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE la shows in a pl.an view an infrared detecting element employed in the infrared sensor according to the present invention;
FIG. lb is a sectioned view of the el.ement of FIG. la taken along l.ine X-X;
FIGS. lc to le, FIGS. lf to lh, FIGS. li to lk and FIGS. ll. to lo are respective]y explanatory views for manufacturing steps in different aspects of the infrared detecting element employed in the present invention;
FIGS. 2 and 3 show in simil.ar plan and sectioned views in another aspect of the infrared detecting element employed in the sensor according to the present invention;
FIG. 4 shows one of circuit arrangements empl.oyable for the infrared sensor according to the CA 022490~7 1998-09-29 present invention;
FIG. 5 shows another exampl.e of the circuit arrangement employable in the present invention;
FIG. 6 shows in a schematic sectioned view an embodiment of the infrared sensor according to the present invention; and FIGS. 7-17 are schematic sectioned views showing other embodiments of the infrared sensor according to the present invention.
While the present invention shall. now be described with reference to the preferred embodiments shown in the drawings, it should be appreciated that the intention is not to ]imit the invention only to these aspects and embodiments shown but rather to incl.ude all alterations, modifications and equival.ent arrangements possible within the scope of appended c]aims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In an infrared detecting el.ement 1 employed in the present invention as shown in FIGS. la and lb, a fil.m section 4 consisting of a dielectric fil.m is constituted by forming the dielectric film on a supporting part 3 consisting, for example, of a Si substrate, and providing in the supporting part 3 a cavity or recess, and a temperature sensing section 5 for absorbing the infrared on the film section 4. Further, a microbridge structure is constituted by providing diaphragm parts or slits in the film section 4. Whil.e it is desirable fundamental.l.y that a second infrared detecting element for temperature CA 022490~7 1998-09-29 compensation is prepared in the same structure as that described above of the first infrared detecting el.ement 1 for the infrared detection so that both e]ements may be empl.oyed in an infrared sensor according to the present invention later described, they need not be a]ways the same. Further, the supporting part 3 needs not be limited to the Si substrate, and may be an alumina substrate or the 1ike.
The dielectric film is constituted by a fi]m of, for example, SiO, SiN, SiON or the l.ike, whereas the temperature sensing section 5 is of a structure in which such element for grasping temperature variation due to the incidence of infrared as thermistor, thermocouple, thermopile, pyroelectric element or SAW e]ement is provided with electrodes for outputting detection signa]s, and, as required, the dielectric fi]m of SiO, SiN, SiON or the ].ike is formed thereon. In attaining thereafter a bridging structure, in particular, the microbridge structure at a part of the film section 4 for supporting the temperature sensing section 5 as shown in FIG. 2, the part of the film is subjected to such etching as RIE
(reactive ion etching) process for allowing parts of supporting beams 6 of such diel.ectric fi]m as SiO, SiN, SiON or the like will be left, to form slits. In forming the supporting section in a diaphragm shape, the etching is carried out by means of a SiN-masking or the l.ike formed on the rear surface. In an event where the etching is to be carried out from surface side of the film section .. . .... . . ..
CA 022490~7 1998-09-29 4 to attain a formation of FIG. 3, further, a bored part is formed on lower side of the temperature sensing section 5 by etching the Si substrate 3 through the si].ts formed in the film section 4. As an etchant, various ones including KOH (potassium hydroxide), EDP (ethylenediamine pyrocatechol), hydrazine, TMAH (tetramethylammonium hydroxide) may be empl.oyed, whil.e an optimum one of them should be selected in accordance with such demanded conditions as protection of the temperature sensing section 5, the side from which the etching is made with respect to the film section 4, presence or absence of contact between the etchant and the surface of the temperature sensing section 5, and so on.
For an arrangement of non-contact support with respect to the supporting part 3, further, such aspects as foll.ows may be employed. As shown in FIGS. lc to le, for exampl.e, the supporting part 3 is mechanically scraped off as indicated by arrows, by means of a sandblasting or the like performed from a surface of the supporting part 3 opposite to the surface on which the temperature sensing section 5 is formed, while l.eaving the dielectric film section 4. In scraping off only a predetermined portion of the part 3, a pattern of resist or the l.ike may be used as a blasting mask, for easil.y carrying out such limited area scraping.
As shown in FIGS. lf to lh, further, a sacrificial l.ayer eventually removed is first made through a pattern formation on the supporting part 3 at part where CA 022490~7 1998-09-29 the temperature sensing section 5 is to be formed, the dielectric fil.m section 4 and sensing section 5 are then formed on the part 3 and sacrificial layer, and final.l.y the sacrificial. layer is removed. At this time, the sacrificial l.ayer may be removed by a etchant used through etching holes. For the material of the sacrificial layer, one which can be removed by an etchant not corrosive to the materials forming the temperature sensing section 5 and film section 4 may be used. Exampl.es of such materia]
will. be polysilicone, aluminum and the l.ike. Further, as shown in FIGS. li to lk, the arrangement may al.so be realized by forming the temperature sensing section 5 and dielectric film section 4 on another substrate 3', joining the substrate 3' and the sections 4 and 5 onto the supporting part 3 with the sensing section 5 positioned within a recess preliminarily made in joining surface of the supporting part 3, and final.]y removing the another substrate 3'. It is also possible to realize the arrangement as shown in FIGS. 1] to lo, wherein the recess prel.iminarily made in the supporting part 3 is first filled with an eventually-removed sacrificia] materia], the diel.ectric film section 4 and temperature sensing section 5 are formed on this supporting part 3 with the section 5 disposed above the sacrificial material, and finally the sacrificial material is removed.
In the first and second infrared detecting elements 1 and 2 of the same structure (see also FIG. 4), the temperature sensing section 5 employs an a-SiC
... . . ..
CA 022490~7 1998-09-29 (amorphous-sil.icon carbide) thermistor formed in a so-called sandwich structure as hel.d between a pair of electrodes consisting of Cr and of a thickness of about 1500 A. This temperature sensing section 5 is formed in a square shape of, for example, 500 ~m at one side, and each support beam 6 of the microbridge structure is made to have a width of 50 ~m.
Now, the measurement of temperature variation is enabled by, as shown in FIG. 4, connecting the respective temperature sensing sections 5 of the first and second infrared detecting elements 1 and 2 in series, applying to them a predetermined voltage V, and measuring variation in the potential Vout at junction point between them. As shown in FIG. 5, further, it may be a]so possible to connect a series circuit of externally fixed resistors R1 and R2 in parallel to the series circuit of the elements 1 and 2.
In FIG. 6, there is shown an embodiment of the infrared sensor according to the present invention, in which sensor the first infrared detecting element 1 for the infrared detection and the second infrared detecting element 2 for the temperature compensation are respectively of such structure as shown, for example, in FIG. 3. These first and second infrared detecting elements 1 and 2 are respectively die-bonded to each of printed wiring boards 131 and 132 on which wire-bonding wires are formed, the boards forming the supporting part 3, and the elements 1 and 2 are connected through wires 14 .
CA 022490~7 1998-09-29 to the respective wires on the printed wiring boards 13 and 132.
On the other hand, a container comprises a general.l.y cyl,indrical cap 10 and a stem 11 secured as wel,ded or the l.ike to an axial. end opening of the cap 10 to close the same, whereas the other axial end of the cap 10 is provided with an incident window 10a which is closed by an infrared transmitting filter 15. Pins 12 acting as electrodes are fixed to the stem 11 as passed therethrough, and these pins 12 are inserted into through holes (not shown) formed in the printed wiring boards 131 and 132 and are fixed thereto as adhered to the boards through conductive paste 17 for electric conduction. The printed wiring board 132 on which the second infrared detecting element 2 is mounted is disposed on l.ower side (the side of the stem 11) within the container, and ceramic-made spacers 16 are fitted over the pins 12 for keeping a predetermined space between the two printed wiring boards 131 and 132. Further, the printed wiring board 131 on which the first infrared detecting element 1 is mounted is disposed on upper side (the side of the incident window 10a) within the container. The pins 12 have flanges 12a of a larger diameter than the through hole in the printed wiring board 132 50 that the board can be positioned at a predetermined height from the stem 11.
Further, the respective printed wiring boards 131 and 132 are fixed to the pins 12 with their mounting surfaces of the infrared detecting el.ements 1 and 2 CA 022490~7 1998-09-29 disposed on the upper side. By disposing thus the element mounting surfaces of the respective printed wiring boards 131 and 132 on the same side, it is made possible to prevent the first and second infrared detecting elements from being damaged upon fixing the pins 12 to the printed wiring board 131 and 132.
Accordingly, in the present embodiment, the disposition of the printed wiring board 131 carrying the first infrared detecting element 1 for the infrared detection on the upper side of the second infrared detecting element 2 causes the infrared incident from the exterior into the incident window lOa through the infrared transmitting filter 15 (which shal.l be referred to as "incident infrared" in the foll.owings) to be incident upon the first infrared detecting el.ement 1 onl.y but to be prevented from reaching the second infrared detecting element 2 as shielded by the printed wiring board 131, and the second infrared detecting element 2 for the temperature compensation can be prevented from being influenced by the incident infrared. It is also enabled to utilize the printed wiring board 131 carrying the first infrared detecting element 1 concurrently as means for shielding the infrared with respect to the second infrared detecting element 2, whereby it is made unnecessary to separatel.y provide such means as the known infrared shielding plate, and any restriction of the angle of view of the first infrared detecting element 1 as well as any remarkable change in the sensitivity according to the CA 022490~7 1998-09-29 angle of view can be el.iminated from occurring. As a result, it should be appreciated that, in cooperation with the disposition of the second infrared detecting element 2 for the temperature compensation in the same container as the first infrared detecting element, any deterioration in the detecting precision due to the variation in the ambient temperature can be prevented at ]ow costs, without any hindrance to the compensation for the ambient temperature.
10Instead of the mounting of the second infrared detecting element 2 for the temperature compensation to the printed wiring board 132, the particular el.ement may be die-bonded directl.y to the stem 11 forming the container, as shown in FIG. 7, in which event the printed 15wiring board 132 as well as the spacers 16 may be made unnecessary, and the manufacturing costs can be further reduced.
Another embodiment of the present invention is shown in FIG. 8, in which the same basic constituents as those in FIG. 6 are denoted by the same reference numerals with their description omitted and on]y characteristic points shall be described in the followings.
In the present embodiment, the second printed wiring board 132 carrying the second infrared detecting element 2 for the temperature compensation is fixed to the pins 12 with the surface carrying the el.ement faced to the lower stem side, while the first printed wiring board 131 carrying the first infrared detecting element 1 for the CA 022490~7 1998-09-29 infrared detection is placed intimately on the second board with the surface carrying the first element faced to the incident window lOa both boards are disposed substantially in the center of the container so that a gap Ll between the first infrared detecting el.ement 1 and the infrared transmitting filter 15 and a gap L2 between the second infrared detecting element 2 and the stem 11 wi].l be substantially equal to each other (Ll L2) and a l.ayer of a l.ower refl.ectance material. such as a black paint than the material of the cap 10 and stem 11 is provided on inner walls of the cap 10 and stem 11 in order to prevent the incident infrared from reaching the second infrared detecting element 2 as refl.ected on the inner wa]ls.
Since other infrared than that incident through the incident window lOa is also incident on the first infrared detecting element 1 due to radiation or the like from the cap 10 and stem 11 of the container the disposition of the second infrared detecting element to face the innermost wal] of the container for rendering the other infrared due to the radiation or the like form the container to be incident also on the element 2 with the same intensity al.lows the intensity of the other infrared incident on both infrared detecting el.ements 1 and 2 than the incident infrared from the incident window lOa to be substantial.ly equal whereby any infl.uence due to the infrared received from the inner wal]s of the container can be compensated for and the detecting precision can be prevented from being deteriorated by the ambient .. . ... .... . . .. .
CA 022490~7 1998-09-29 temperature change.
In the present embodiment, further, the temperature sensing section 5 in each of the first and second infrared detecting elements 1 and 2 is constituted by a thermistor which causes a temperature variation to occur with its own heat generation, but a driving of the temperature sensing section 5 with a constant voltage or current is so performed that the own heat release val.ue wil1 vary in response to variation in the resistance val.ue of the thermistor due to the variation in the ambient temperature. To this own heat release value, the heat conductance relying on heat insul.ating structure of the infrared detecting elements 1 and 2 is determinative, and this heat conductance is determined by a sum of the heat conductance of the supporting diaphragm or microbridge for the temperature sensing section 5 and the heat conductance of ambient gas. Here, the heat conductance of the ambient gas is l.argel.y influenced by the gap L1 between the first infrared detecting el.ement 1 and the fi]ter 15 and the gap L2 between the second infrared detecting el.ement 2 and the stem 11, and any difference between these gaps causes a difference to arise in the heat conductance, whereby a difference is caused to arise in the own heat release value to render a heat difference to occur in the temperature sensing section 5.
At this time, in the present instance, the heat conductance can be made substantiall.y equal with respect to both temperature sensing sections 5 of the first and CA 022490~7 1998-09-29 second infrared detecting elements 1 and 2 by substantially equalizing both gaps Ll and L2, and the detecting precision can be prevented from being deteriorated due to the change in ambient temperature by rendering any temperature rise due to the own heat generation at the temperature sensing sections 5 to be in conformity to each other. Further, because of these respects, it is enabled to realize an infrared sensor further higher in the detecting precision than the embodiment of FIG. 6.
Further, because of the provision of the l.ayer of lower reflectance than the cap 10 and stem 11 by the application of black paint on the inner wall.s of the container, it is enabled to prevent the infrared reflecting on the inner walls of the container even in the case of wide angle of view, to prevent unnecessary infrared from being incident on the second infrared detecting element 2 for the temperature compensation, and, consequently, to realize an infrared sensor of a wide angle of view.
In another embodiment shown in FIG. 9 of the present invention, the first and second infrared detecting elements 1 and 2 are respectively mounted onto each of both surfaces of a single printed wiring board 18 having the printed wirings on the both surfaces, whil.e the second infrared detecting el.ement 2 is die-bonded to a recess 18a formed in the surface facing the stem 11 and the board 18 is brought into contact at least at peripheral edges with . .
CA 022490~7 1998-09-29 the inner walls of the cap 10.
By mounting in this way the first and second infrared detecting elements 1 and 2 respective]y onto each of front and rear surfaces of the single printed wiring board, it is enabled to reduce the manufacturing costs by the fact that only one printed wiring board 18 is required for mounting the two elements 1 and 2, and that required mounting work is simp]ified. It is also possible to render the recess 18a made in the printed wiring board 18 to have a depth enough for keeping the second infrared detecting element 2 in the recess 18a as we]l as the wires 14 not to project out of the rear, mounting surface of the board 18, whereby, when the mounting is made first for the second infrared detecting element 2 in the recess 18a on the rear surface and thereafter for the first infrared detecting element 1 onto the other front surface of the board 18, the second infrared detecting element 2 mounted initial can be prevented from being damaged by any jig or the like that may hit the element 2 upon mounting later the first infrared detecting element 1.
Further, since the printed wiring board 18 is brought into contact at the peripheral edges with the inner walls of the cap 10 of the container, the board 18 is improved in the ability of follow-up to the ambient temperature, the first and second infrared detecting elements 1 and 2 are made thereby to well follow the ambient temperature, and the detecting precision can be improved by achieving the temperature compensation with CA 022490~7 1998-09-29 the ambient temperature precisely monitored.
In the present embodiment, further, a gas communicating hole 18b is made as passed through the printed wiring board 18, and Xe gas of a l.ow heat conduction is seal.ed in the container. In substituting the low heat conduction gas for air inside the container for improving the sensitivity or in sealing the interior of the container by drawing a vacuum, therefore, it is made easier to discharge the gas in a space partitioned by the printed wiring board 18 on upper side thereof through the gas communicating hol.e 18b made in the board 18, and there arises an advantage that an improvement in the productlvity as well. as a reduction in the manufacturing costs can be attained.
In the embodiment of FIG. 9, other constituents are the same as those in the embodiment of FIG. 6 and are denoted by the same reference numera].s as those used in FIG. 6.
In FIG. 10, another embodiment according to the present invention is shown, in which the stem 11 of the container is molded integral with the pins 12 passed through the stem, and the short cylindrical cap 10 made of a metal, for example, is fitted over one front surface of the stem to be closed by the latter at one end opening, to define the space between them. The other end opening is closed by the infrared transmitting filter 15.
Within the space and on top ends of the pins 12 erected from the stem 11, the printed wiring board 13 is .......... . .
CA 022490~7 1998-09-29 secured, and the infrared detecting element 1 and a thermistor 7 as a contact type temperature sensor for measuring the temperature of the element 1 are mounted on the board 13. Here, the pins 12 may be provided to act also as output terminals for signal.s of the element 1 and thermistor 7. Further, the cap 10 defining the interior space in conjunction with the stem 11 is provided on the inner surfaces with thin heat radiating fins lOc.
With the provision of the heat radiating fins lOc, further, the time constant at which the temperature of the cap 10 coincides with the temperature of the interior space defined by the cap 10 and stem 11 can be made smaller, the temperature of the infrared detecting element 1, thermistor 7 as a temperature detecting means, cap 10 and stem 11 can be quickly stabi]ized even in the circumstances where the ambient temperature is apt to vary, and the temperature can be measured at a high precision. Further, with the temperature of the infrared detecting element thus enabl.ed to be measured by means of the thermister, it is made possible to correct any error in output signals occurring due to the ambient temperature variation, and the detecting precision can be further elevated.
Since the infrared detecting element 1 and thermistor 7 in the foregoing embodiments of FIGS. 9 and 10 are mounted on the single printed wiring board 13, further, they vary at the same temperature gradient, so as to be able to elevate the detecting precision even in a CA 022490~7 1998-09-29 state where the variation in the ambient temperature occurs.
In another embodiment shown in FIG. 11 of the present invention, the cap 10 in the embodiment of FIG. 10 is replaced by a cap lOA made with two metal members joined to be a double structure having an interior gap lOa filled with air.
While in the present embodiment the interior of the cap lOA is made to be the air layer lOa, the same is not required to be limited thereto but the interior may be fil.led with other gas or may even be drawn a vacuum.
Normally, the cap lOA and stem 11 are different in the heat capacity due to the difference in the thickness so that, in an event of variation in the ambient temperature, the temperature variation is apt to occur initially on the side of the cap lOA, but the present embodiment employing the cap lOA of the double structure having in the interior the air l.ayer lOa is capable of moderating the temperature fl.uctuation in the inner wall surface of the cap lOA, so that the infrared fl.ux from the inner wall. surface of the cap lOA and stem 11 to the infrared detecting elements 1 and 2 will. be substantial]y identical, and the detecting precision can be improved.
Further, as the temperature fluctuation in the space defined by the cap lOA and stem 11 can be moderated, the temperature fluctuation at the infrared detecting el.ements 1 and 2 and thermistor 7 can be also moderated, so that any difference in the temperature between these el.ements . . .
CA 022490~7 1998-09-29 can be minimized to render the detecting precision more excellent.
In the embodiment of FIG. 11, on the other hand, it is also possible to emp]oy a vacuum pressure arrangement with the interior space of the cap 10 and stem 11 drawn a vacuum preferably to be bel.ow 1 Pa. In this case, the thermal. conduction from the cap 10 and stem 11 to the infrared detecting elements 1 and 2 and thermister 7 is remarkably reduced even upon change in the ambient temperature, so as to relieve the temperature fluctuation, accordingly any temperature difference is l.ess caused to occur between these constituents, and the detecting precision can be further improved.
Other constituents of this embodiment are the same as those in the embodiment of FIG. 10, and the same constituents as those shown in FIG. 10 are denoted in FIG.
11 by the same reference numerals as used in FIG. 10.
In another embodiment shown in FIG. 12 of the present invention, the container is constituted simil.arly with the stem 11 molded integrally with the pins 12, and the short cylindrical cap 10 a bottom end opening of which is closed by the stem 11 to define an interior space, while the top end of the cap 10 is formed to have the incident window closed by the infrared transmitting fil.ter 15.
Within the interior space defined by the cap 10 and stem 11, the infrared detecting element 1 and the thermistor 7 as the contacting type temperature detecting CA 022490~7 1998-09-29 element for measuring the temperature of the infrared detecting element 1 are mounted on the stem 11, and the pins 12 are also acting as the signa]. output terminals of the element 1 and thermistor 7.
As a distinguishing feature here, the cap 10 and stem 11 are formed to have substantia]]y the same thickness.
In the present embodiment, therefore, the cap 10 and stem 11 can be made to have an identical. or the same level of the heat capacity by the same thickness, so that there arises no uneven temperature variation as the same temperature variation takes pl.ace in the cap 10 and stem 11 even upon variation in the ambient temperature, the infrared flux from the inner wall. surface of the cap 10 and stem 11 to the respective infrared detecting elements 1 and 2 can be made substantially identical., and the detecting precision can be improved.
In another embodiment shown in FIG. 13, in contrast to the embodiment of FIG. 10, such paint lOb of which the radiant emissivity is prel.iminarily known as the black paint is applied to parts of the inner wal.l.s of the cap 10 and stem 11 which are included in the ang]e of view of the infrared detecting el.ements 1 and 2. In the present instance, the infrared radiant emissivity is made constant on the inner surface of the cap 10 and stem 11 included in the angl.e of view of both elements 1 and 2, the infrared flux from the inner surface to the elements 1 and 2 will. be made substantially identical., and the CA 022490~7 1998-09-29 detecting precision can be improved.
In the embodiment of FIG. 13, further, the paint 10b may be rep].aced by a use or exec~tion of a mater1a]
for the whole or for surface layer or of a surface treatment with respect to the cap 10 and stem 11 and attaining the same effect as the paint 10b.
Other constituents of the present embodiment are the same as those in the embodiment of FIG. 10, and the same constituents are denoted in FIG. 13 by the same reference numerals as those in FIG. 10.
As another embodiment, the bl.ack paint 10b in FIG. 13 is replaced by a pl.ating of metal or the like to attain a lower radiant emissivity. In this case, the lower radiant emissivity at the inner walls of the cap 10 and stem 11 at least at portions included in the angle of view of the infrared detecting elements 1 and 2 renders the infrared flux from the inner wal]s of the cap 10 and stem 11 to the elements 1 and 2 to be smal.l enough to be substantial.l.y the same even when a temperature difference arises between the cap 10 and the stem 11 due to any variation in the ambient temperature, and the detecting precision can be improved. In this case, it is al.so preferabl.e to attain a mirror finish at the surface of the cap 10 and stem 11.
In another embodiment of the present invention as shown in FIG. 14, a further thermistor 9 is provided as adhered to an inner wall of the cap 10, in contrast to the embodiment of FIG. 10. In this case, it is made possibl.e CA 022490~7 1998-09-29 to predict an extent of variation in the output of the infrared detecting el.ement 1 due to the temperature variation of the cap 10, by measuring the temperature of the cap 10 by means of the thermistor 9.
Other constituents of thls embodiment are the same as those in the embodiment of FIG. 10, and the same constituents are denoted in FIG. 14 by the same reference numerals as those in FIG. 10.
In still another embodiment of the present invention as shown in FIG. 15, there are provided a plurality of the thermistors 7 for detecting the temperature at respective portions of the cap 10, stem 11, infrared transmitting fi].ter 15, infrared detecting element 1 and printed wiring board 13.
The calorie which is detected by the infrared detecting element 1 can be represented by a formula ~a-~a(Ta -Ts4) ................. (1) wherein ~a is the ratio of the angl.e of view at the incident window of the cap 10, ~a is the radiant emissivity of an objective, Ta is the temperature of the objective, and TS is the temperature of the infrared detecting element 1.
In an event where the ambient temperature is stable and the temperature at portions of the package within the angle of view of the infrared detecting element 1 (at the cap 10, stem 11 and infrared transmitting filter 15) coincides with the temperature of the infrared detecting element 1, the relation of incident infrared CA 022490~7 1998-09-29 flux at the infrared detecting element to the e]ement temperature and to the objective temperature can be obtained with the above formula (1), whereas, as the ambient temperature varies to render the temperature at the package portions in the angle of view of the element 1 to be different from the temperature of the element 1, then the infrared from the package is caused to be detected in addition to the infrared from the objective, and there occurs an error.
Here, the temperature correction factor at the package portions can be represented by a formula (T14-Ts4)+~2~2(T24-Ts )+ ~-- +~n- n( n s ..... (2) wherein ~n denotes the ratio of the angle of view at the package portions n, ~n denotes the radiant emissivity at the package portions n, and Tn denotes the temperature at the package portions n.
Now, by applying the output from the thermistors 7 to the above formula (2) and obtaining the sum or difference of the formulas (1) and (2), it is made possible to improve the detecting precision.
In another embodiment of the present invention as shown in FIG. 16, there is a difference from the embodiment of FIG. 10 in that, instead of the separate provision of the thermistor 7 as the temperature detecting means, the temperature of the temperature sensing section itself of one or both of the infrared detecting elements 1 and 2 is measured, for the correction of the detected CA 022490~7 1998-09-29 signals with the thus measured temperature value. More specifically, the temperature sensing section of these infrared detecting elements is constituted by the thermistor, and the temperature of the temperature sensing section is measured by obtaining the resistance value of the thermistor. While in the foregoing formu].a (1) the temperature Ts is denoted as that of the infrared detecting element, the infrared from the objective is to be received at the temperature sensing section in practice, and the temperature TS should be denoted inherently as that of the temperature sensing section of the infrared detecting element. When the general.
temperature variation is small., on the other hand, there arises no remarkabl.e temperature difference between the temperature sensing section and the separately provided temperature detecting means, and the temperature T may be denoted as the temperature of the infrared detecting element.
Here, in the case where the temperature difference is apt to occur between the respective parts in such event that the temperature at the respective parts of the sensor is varying due to the variation in the ambient temperature, there occurs the temperature difference between the temperature sensing section and the temperature detecting means, and it wil.l. be required, for accurate detection, to measure the temperature of the temperature sensing section in the infrared detecting el.ement. Since in the present embodiment the temperature CA 022490~7 1998-09-29 of the temperature sensing section itself is measured the detection is enabled at a higher precision.
In the present invention various design modification is possible within the scope of appended claims. In the embodiment of FIG. 14 for example the thermistor 9 provided on the inner surface of the cap 10 may be omitted as shown in FIG. 17 to employ only the single thermistor 7 mounted on the supporting substrate 13 along with the first infrared detecting element 1 for simplifying the arrangement in adaption to the use.
Further it should be appreciated that the embodiments of FIGS. 10 through 17 are respectively capable of mutual~y incorporating their characteristic arrangement of another embodiment.
, .. .. . . . .
Claims (21)
1. An infrared sensor comprising a container having an infrared incident window, first infrared detecting element for infrared detection and disposed inside the container as supported by a printing wiring board in opposition to the incident window, and second infrared detecting element for temperature compensation and disposed inside the container with the infrared shielded by the printed wiring board supporting the first infrared detecting element from being incident on the second infrared detecting element, wherein at least the first infrared detecting element comprises an electrically insulating supporting substrate having a cavity, and a temperature sensing section supported above the cavity by a dielectric film in non-contacting state with respect to the supporting substrate for the element, the temperature sensing section of the first infrared detecting element being connected to a wiring on the printed wiring board to have a sensed temperature variation at the temperature sensing section of the first infrared detecting element converted into an infrared detection signal.
2. The infrared sensor according to claim 1 wherein the second infrared detecting element is disposed to face in a direction opposite to the incident window of the container.
3. The infrared sensor according to claim 1 wherein the second infrared detecting element is disposed on a surface of the printed wiring board opposite to a surface on which the first infrared detecting element is supported.
4. The infrared sensor according to claim 3 wherein at least one of the surfaces on which printed wirings are mounted of the printed wiring board is provided with a recess for mounting therein at least one of the first and second infrared detecting elements, the recess being of a depth enough for not projecting the mounted element out of the one surface.
5. The infrared sensor according to claim 1 wherein the second infrared detecting element comprises a temperature sensing section substantially equalized in the heat capacity and in the heat conductance to surroundings, to the sensing section of the first infrared detecting element.
6. The infrared sensor according to claim 1 wherein the second infrared detecting element comprises a temperature sensing section facing opposite to the infrared incident window, and gaps respectively between the temperature sensing section of the first infrared detecting element and the incident window and between the temperature sensing section of the second infrared detecting element and one of constituents of the container opposing to the temperature sensing section of the second infrared detecting element are substantially equal to each other.
7. The infrared sensor according to claim 2 wherein the second infrared detecting element comprises a temperature sensing section facing opposite to the infrared incident window, and gaps respectively between the temperature sensing section of the first infrared detecting element and the incident window and between the temperature sensing section of the second infrared detecting element and one of constituents of the container opposing to the temperature sensing section of the second infrared detecting element are substantially equal to each other.
8. The infrared sensor according to claim 3 wherein gaps respectively between the temperature sensing section of the first infrared detecting element and the infrared incident window and between the temperature sensing section of the second infrared detecting element and one of the constituents of the container opposing to the temperature sensing section of the second infrared detecting element are substantially equal to each other.
9. The infrared sensor according to claim 1 wherein the container comprises a cap having the infrared incident window and an opening, and a stem disposed to close the opening, the stem including pins for supporting the printed wiring board within the container, and the pins being provided with projections for positioning the printed wiring board.
10. The infrared sensor according to claim 1 wherein the container has a layer of a lower reflectance than a material of the container and formed on inner walls of the container.
11. The infrared sensor according to claim 1 wherein at least part of the printed wiring board is brought into contact with the container.
12. The infrared sensor according to claim 1 wherein the container is provided on inner walls thereof with thin heat radiating fins.
13. The infrared sensor according to claim 1 wherein the container comprises a stem and a cap, and the cap is formed with two metal members in a double structure to define therein a gap forming a heat insulating layer.
14. The infrared sensor according to claim 1 wherein the container comprises a stem and a cap which are of the same thickness.
15. The infrared sensor according to claim 1 wherein the interior of the container is drawn a vacuum.
16. The infrared sensor according to claim 1 wherein the container is made constant in the infrared radiant emissivity at least at a portion inside the container and within detecting sight of the first infrared detecting element.
17. The infrared sensor according to claim 1 wherein the container is made low in the infrared radiant emissivity at least at a portion inside the container and within detecting sight of the first infrared detecting element.
18. The infrared sensor according to claim 1 which further comprises means for measuring the temperature of at least one of the first and second infrared detecting elements and the container, a measured temperature value of which means being used for correcting the infrared detection signal to render any error in the signal occurring due to change in the ambient temperature to be substantially zero.
19. The infrared sensor according to claim 18 which further comprises means for obtaining occupying ratios of the radiant emissivity and the reflectance preliminarily obtained with respect to the interior of the container, and of the radiant emissivity and reflectance at a portion of the container interior within the sight of the first infrared detecting element, the ratios obtained being used for the correction of the infrared detection signal.
20. The infrared sensor according to claim 18 which further comprises means for detecting a temperature at the infrared incident window as the temperature at a portion inside the container.
21. The infrared sensor according to claim 18 wherein the temperature measuring means measures the temperature at a position of the temperature sensing section as the temperature of the infrared detecting element.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP294746/1997 | 1997-10-28 | ||
| JP9294746A JPH11132857A (en) | 1997-10-28 | 1997-10-28 | Infrared detector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2249057C true CA2249057C (en) | 2000-12-26 |
Family
ID=17811779
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002249057A Expired - Fee Related CA2249057C (en) | 1997-10-28 | 1998-09-29 | Infrared sensor |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US6236046B1 (en) |
| EP (1) | EP0913675A1 (en) |
| JP (1) | JPH11132857A (en) |
| AU (1) | AU712708B2 (en) |
| CA (1) | CA2249057C (en) |
Families Citing this family (73)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100290870B1 (en) * | 1999-03-27 | 2001-05-15 | 구자홍 | resistive bolometer sensor |
| US6483101B1 (en) * | 1999-12-08 | 2002-11-19 | Amkor Technology, Inc. | Molded image sensor package having lens holder |
| US6483030B1 (en) * | 1999-12-08 | 2002-11-19 | Amkor Technology, Inc. | Snap lid image sensor package |
| US20010007475A1 (en) * | 2000-01-06 | 2001-07-12 | Asahi Kogaku Kogyo Kabushiki Kaisha | Image pickup device and its mounting structure for an optical low-pass filter |
| JP4401582B2 (en) * | 2001-02-26 | 2010-01-20 | 富士通株式会社 | Infrared imaging device |
| US6988073B2 (en) | 2001-05-10 | 2006-01-17 | International Business Machines Corporation | Method, system, and product for facilitating international travel with respect to immigration |
| DE10144343A1 (en) * | 2001-09-10 | 2003-03-27 | Perkinelmer Optoelectronics | Sensor for contactless measurement of a temperature |
| ATE274732T1 (en) * | 2001-11-05 | 2004-09-15 | Siemens Building Tech Ag | PASSIVE INFRARED DETECTOR |
| US6770882B2 (en) * | 2002-01-14 | 2004-08-03 | Multispectral Imaging, Inc. | Micromachined pyro-optical structure |
| JP2004045330A (en) * | 2002-07-15 | 2004-02-12 | Ricoh Co Ltd | Noncontact temperature detector |
| US7296458B2 (en) * | 2002-10-17 | 2007-11-20 | Advanced Technology Materials, Inc | Nickel-coated free-standing silicon carbide structure for sensing fluoro or halogen species in semiconductor processing systems, and processes of making and using same |
| US7080545B2 (en) | 2002-10-17 | 2006-07-25 | Advanced Technology Materials, Inc. | Apparatus and process for sensing fluoro species in semiconductor processing systems |
| US20040163445A1 (en) * | 2002-10-17 | 2004-08-26 | Dimeo Frank | Apparatus and process for sensing fluoro species in semiconductor processing systems |
| DE10321640B4 (en) * | 2003-05-13 | 2016-12-22 | Heimann Sensor Gmbh | Infrared sensor with improved radiation efficiency |
| DE10321639A1 (en) * | 2003-05-13 | 2004-12-02 | Heimann Sensor Gmbh | Infrared sensor with optimized use of space |
| US6934065B2 (en) * | 2003-09-18 | 2005-08-23 | Micron Technology, Inc. | Microelectronic devices and methods for packaging microelectronic devices |
| JP4496751B2 (en) * | 2003-10-09 | 2010-07-07 | 日本電気株式会社 | Thermal infrared solid-state imaging device and manufacturing method thereof |
| US7583862B2 (en) * | 2003-11-26 | 2009-09-01 | Aptina Imaging Corporation | Packaged microelectronic imagers and methods of packaging microelectronic imagers |
| WO2005078458A1 (en) * | 2004-02-05 | 2005-08-25 | Analog Devices, Inc. | Capped sensor |
| US7253397B2 (en) * | 2004-02-23 | 2007-08-07 | Micron Technology, Inc. | Packaged microelectronic imagers and methods of packaging microelectronic imagers |
| JP2005241457A (en) | 2004-02-26 | 2005-09-08 | Hamamatsu Photonics Kk | Infrared sensor, and manufacturing method therefor |
| US7253957B2 (en) * | 2004-05-13 | 2007-08-07 | Micron Technology, Inc. | Integrated optics units and methods of manufacturing integrated optics units for use with microelectronic imagers |
| US8092734B2 (en) * | 2004-05-13 | 2012-01-10 | Aptina Imaging Corporation | Covers for microelectronic imagers and methods for wafer-level packaging of microelectronics imagers |
| JP4751386B2 (en) * | 2004-05-20 | 2011-08-17 | メディシム リミテッド | Temperature measuring device |
| US20050275750A1 (en) | 2004-06-09 | 2005-12-15 | Salman Akram | Wafer-level packaged microelectronic imagers and processes for wafer-level packaging |
| US7498647B2 (en) | 2004-06-10 | 2009-03-03 | Micron Technology, Inc. | Packaged microelectronic imagers and methods of packaging microelectronic imagers |
| US7262405B2 (en) * | 2004-06-14 | 2007-08-28 | Micron Technology, Inc. | Prefabricated housings for microelectronic imagers |
| US7199439B2 (en) * | 2004-06-14 | 2007-04-03 | Micron Technology, Inc. | Microelectronic imagers and methods of packaging microelectronic imagers |
| US7232754B2 (en) * | 2004-06-29 | 2007-06-19 | Micron Technology, Inc. | Microelectronic devices and methods for forming interconnects in microelectronic devices |
| US7294897B2 (en) * | 2004-06-29 | 2007-11-13 | Micron Technology, Inc. | Packaged microelectronic imagers and methods of packaging microelectronic imagers |
| US7416913B2 (en) * | 2004-07-16 | 2008-08-26 | Micron Technology, Inc. | Methods of manufacturing microelectronic imaging units with discrete standoffs |
| US7189954B2 (en) * | 2004-07-19 | 2007-03-13 | Micron Technology, Inc. | Microelectronic imagers with optical devices and methods of manufacturing such microelectronic imagers |
| US7402453B2 (en) * | 2004-07-28 | 2008-07-22 | Micron Technology, Inc. | Microelectronic imaging units and methods of manufacturing microelectronic imaging units |
| US20060023107A1 (en) * | 2004-08-02 | 2006-02-02 | Bolken Todd O | Microelectronic imagers with optics supports having threadless interfaces and methods for manufacturing such microelectronic imagers |
| US7364934B2 (en) * | 2004-08-10 | 2008-04-29 | Micron Technology, Inc. | Microelectronic imaging units and methods of manufacturing microelectronic imaging units |
| US7397066B2 (en) * | 2004-08-19 | 2008-07-08 | Micron Technology, Inc. | Microelectronic imagers with curved image sensors and methods for manufacturing microelectronic imagers |
| US7223626B2 (en) * | 2004-08-19 | 2007-05-29 | Micron Technology, Inc. | Spacers for packaged microelectronic imagers and methods of making and using spacers for wafer-level packaging of imagers |
| US7429494B2 (en) | 2004-08-24 | 2008-09-30 | Micron Technology, Inc. | Microelectronic imagers with optical devices having integral reference features and methods for manufacturing such microelectronic imagers |
| US7115961B2 (en) * | 2004-08-24 | 2006-10-03 | Micron Technology, Inc. | Packaged microelectronic imaging devices and methods of packaging microelectronic imaging devices |
| US7425499B2 (en) | 2004-08-24 | 2008-09-16 | Micron Technology, Inc. | Methods for forming interconnects in vias and microelectronic workpieces including such interconnects |
| US7276393B2 (en) * | 2004-08-26 | 2007-10-02 | Micron Technology, Inc. | Microelectronic imaging units and methods of manufacturing microelectronic imaging units |
| US7511262B2 (en) * | 2004-08-30 | 2009-03-31 | Micron Technology, Inc. | Optical device and assembly for use with imaging dies, and wafer-label imager assembly |
| US20070148807A1 (en) * | 2005-08-22 | 2007-06-28 | Salman Akram | Microelectronic imagers with integrated optical devices and methods for manufacturing such microelectronic imagers |
| US7646075B2 (en) * | 2004-08-31 | 2010-01-12 | Micron Technology, Inc. | Microelectronic imagers having front side contacts |
| US7300857B2 (en) | 2004-09-02 | 2007-11-27 | Micron Technology, Inc. | Through-wafer interconnects for photoimager and memory wafers |
| KR100577430B1 (en) | 2004-09-03 | 2006-05-08 | 삼성전자주식회사 | Display apparatus |
| US7271482B2 (en) * | 2004-12-30 | 2007-09-18 | Micron Technology, Inc. | Methods for forming interconnects in microelectronic workpieces and microelectronic workpieces formed using such methods |
| US7214919B2 (en) * | 2005-02-08 | 2007-05-08 | Micron Technology, Inc. | Microelectronic imaging units and methods of manufacturing microelectronic imaging units |
| US20060177999A1 (en) * | 2005-02-10 | 2006-08-10 | Micron Technology, Inc. | Microelectronic workpieces and methods for forming interconnects in microelectronic workpieces |
| US7303931B2 (en) * | 2005-02-10 | 2007-12-04 | Micron Technology, Inc. | Microfeature workpieces having microlenses and methods of forming microlenses on microfeature workpieces |
| US7190039B2 (en) * | 2005-02-18 | 2007-03-13 | Micron Technology, Inc. | Microelectronic imagers with shaped image sensors and methods for manufacturing microelectronic imagers |
| US20060211253A1 (en) * | 2005-03-16 | 2006-09-21 | Ing-Shin Chen | Method and apparatus for monitoring plasma conditions in an etching plasma processing facility |
| US7795134B2 (en) * | 2005-06-28 | 2010-09-14 | Micron Technology, Inc. | Conductive interconnect structures and formation methods using supercritical fluids |
| US20060290001A1 (en) * | 2005-06-28 | 2006-12-28 | Micron Technology, Inc. | Interconnect vias and associated methods of formation |
| KR100688564B1 (en) * | 2005-07-29 | 2007-03-02 | 삼성전자주식회사 | Jig for testing semiconductor chip and method of testing semiconductor chip using the same |
| US7262134B2 (en) * | 2005-09-01 | 2007-08-28 | Micron Technology, Inc. | Microfeature workpieces and methods for forming interconnects in microfeature workpieces |
| US7288757B2 (en) * | 2005-09-01 | 2007-10-30 | Micron Technology, Inc. | Microelectronic imaging devices and associated methods for attaching transmissive elements |
| US7897920B2 (en) * | 2005-09-21 | 2011-03-01 | Analog Devices, Inc. | Radiation sensor device and method |
| US8476591B2 (en) * | 2005-09-21 | 2013-07-02 | Analog Devices, Inc. | Radiation sensor device and method |
| EP2097725B1 (en) * | 2006-12-27 | 2019-08-28 | Analog Devices, Inc. | Control aperture for an ir sensor |
| GB0709224D0 (en) * | 2007-05-14 | 2007-06-20 | Melexis Nv | IR Radiometer |
| US7905855B2 (en) * | 2007-07-05 | 2011-03-15 | Baxter International Inc. | Dialysis system having non-invasive temperature sensing |
| DE102008031285A1 (en) * | 2008-07-02 | 2010-01-07 | Mahlo Gmbh + Co. Kg | Sensor arrangement for the pyrometric measurement of the temperature of a measurement object |
| US20100194465A1 (en) * | 2009-02-02 | 2010-08-05 | Ali Salih | Temperature compensated current source and method therefor |
| US8753008B2 (en) | 2009-06-26 | 2014-06-17 | Fluke Corporation | Protective enclosure for a thermal imaging device of an industrial monitoring system |
| JP5793679B2 (en) * | 2009-12-18 | 2015-10-14 | パナソニックＩｐマネジメント株式会社 | Infrared sensor module |
| JP5767883B2 (en) * | 2011-07-26 | 2015-08-26 | 浜松ホトニクス株式会社 | Spectrometer |
| CN105556365B (en) * | 2013-08-08 | 2018-02-02 | 夏普株式会社 | Optical transmission device, guide-lighting plug, Optical fiber plug, sensitive device, electrical socket and portable equipment |
| CN105452826B (en) * | 2013-08-09 | 2019-07-23 | 世美特株式会社 | Infrared temperature sensor and the device for utilizing infrared temperature sensor |
| GB2527348A (en) | 2014-06-19 | 2015-12-23 | Melexis Technologies Nv | Infrared sensor with sensor temperature compensation |
| DE102015208701A1 (en) * | 2015-05-11 | 2016-11-17 | Infratec Gmbh | Device for the simultaneous determination of several different substances and / or substance concentrations |
| CN109416277A (en) * | 2016-07-04 | 2019-03-01 | 株式会社堀场制作所 | Infrared detector and radiation thermometer |
| JP6741201B2 (en) | 2017-03-14 | 2020-08-19 | 三菱マテリアル株式会社 | Infrared sensor |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54174384U (en) | 1978-05-30 | 1979-12-08 | ||
| GB2133615B (en) * | 1982-12-15 | 1986-03-19 | Philips Electronic Associated | Pyroelectric infra-red radiation detector |
| JPS6150232A (en) | 1984-08-18 | 1986-03-12 | Matsushita Electric Ind Co Ltd | Optical recording medium and its manufacture |
| US4722612A (en) * | 1985-09-04 | 1988-02-02 | Wahl Instruments, Inc. | Infrared thermometers for minimizing errors associated with ambient temperature transients |
| JPH06317475A (en) * | 1991-07-19 | 1994-11-15 | Terumo Corp | Infrared sensor and fabrication thereof |
| WO1994007115A1 (en) * | 1992-09-17 | 1994-03-31 | Mitsubishi Denki Kabushiki Kaisha | Infrared detector array and production method therefor |
| US5645349A (en) * | 1994-01-10 | 1997-07-08 | Thermoscan Inc. | Noncontact active temperature sensor |
| DE19526557A1 (en) * | 1994-07-20 | 1996-01-25 | Raytek Sensorik Gmbh | Infrared temperature measuring device |
-
1997
- 1997-10-28 JP JP9294746A patent/JPH11132857A/en active Pending
-
1998
- 1998-09-29 AU AU87128/98A patent/AU712708B2/en not_active Ceased
- 1998-09-29 CA CA002249057A patent/CA2249057C/en not_active Expired - Fee Related
- 1998-10-06 EP EP98203360A patent/EP0913675A1/en not_active Withdrawn
- 1998-10-07 US US09/167,996 patent/US6236046B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0913675A1 (en) | 1999-05-06 |
| JPH11132857A (en) | 1999-05-21 |
| US6236046B1 (en) | 2001-05-22 |
| AU712708B2 (en) | 1999-11-11 |
| AU8712898A (en) | 1999-05-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2249057C (en) | Infrared sensor | |
| US7180063B2 (en) | Thermal infrared detector having a small thermal time constant and method of producing the same | |
| JP6279660B2 (en) | Device for detecting electromagnetic radiation | |
| US5645349A (en) | Noncontact active temperature sensor | |
| US7005642B2 (en) | Infrared sensor and electronic device using the same | |
| JP5384710B2 (en) | Capacitive pressure sensor | |
| EP0354479B1 (en) | Semiconductor pressure sensor | |
| US4703658A (en) | Pressure sensor assembly | |
| JP3097591B2 (en) | Thermal infrared detector | |
| JP4307738B2 (en) | Pressure sensor | |
| US20070069133A1 (en) | Microbolometer IR Focal Plane Array (FPA) with In-Situ Micro Vacuum Sensor and Method of Fabrication | |
| US20030123517A1 (en) | Non-contact temperature sensor and detection circuit for the same | |
| KR100539205B1 (en) | Measuring tip for a radiation thermometer | |
| JP2008501963A (en) | Sensor | |
| JP2011149920A (en) | Infrared sensor | |
| US5693942A (en) | Infrared detector | |
| CN111174908A (en) | Laser detector and corresponding laser power meter | |
| JP2008501964A (en) | Sensor element | |
| JPH07190854A (en) | Infrared sensor | |
| JPH1164111A (en) | Infrared detecting element | |
| CN112649144A (en) | High-temperature-resistant pressure sensor packaging structure based on optical detection | |
| JPH11337415A (en) | Radiation temperature detecting element | |
| JP3083901B2 (en) | Atmosphere sensor | |
| JPH075047A (en) | Radiation heat sensor | |
| JP3855458B2 (en) | Radiation temperature detector |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20160929 |