US3009012A - Header construction - Google Patents

Description

Nov. 14, 1961 J. P. POLESE HEADER CONSTRUCTION Filed Sept. 12, 1958 E I n RE M m 0 N .T EP 2 M V R w lM H A J United States Patent: Q

3,009,012 HEADER CONSTRUCTHON James P. Polese, Menlo Park, Calif, assignor to General Electric Company, a corporation of New York Filed Sept. 12, 1958, Ser. No. 760,764 7 Claims. (Cl. 174-151) My invention relates to electric discharge devices and similar devices including hermetically sealed envelopes and requiring means for making electrical connections through the walls of such envelopes to electrically coopcrating means therein. More particularly, my invention relates to an improved multiple-lead, high-vacuum header construction adapted for high-frequency, high-temperature applications and for use where ruggedness of construction and resistance to thermal shock are important factors.

Glass multiple-lead headers are found in the prior art but are not suitable for certain applications such, for ex ample, as in the very high-frequency and high-temperature electric discharge devices or for use in devices subject to high vibratory environments and wide temperature ranges. Heretofore, ceramic headers including multiple leads have been employed in these applications. However, these prior art headers generally required metalizing the internal surfaces of elongated apertures through a ceramic element to enable brazing of leads therein. With this type of structure special metalizing methods were required for uniformly metalizing the interior surfaces of the lead apertures and in insuring a satisfactory hermetic braze. Additionally, a tight fit of the leads in the apertures was generally required to obtain a satis factory braze and this presented difficulties in connection with ceramic cracking due to differences in expansion characteristics andwhich, in order to avoid such cracking, required substantial care in matching of materials. Additionally, some of the prior art headers have not proved sufliciently rugged to withstand substantial vibration over extended periods and have been unable to with stand the thermal shock associated with temperature changes through wide temperature ranges.

Accordingly, a primary object of my invention is to provide a new and improved ceramic header construction adapted for high-frequency and high-temperature applications and which is rugged and adapted for withstanding substantial vibratory and thermal shocks.

Another object of my invention is to provide a new and improved ceramic header construction which can be manufactured easily and inexpensively, is particularly adapted for mass production techniques, and is reliable in service.

Another object of my invention is to provide a new and improved ceramic header construction including mutually insulated multiple leads, an exhaust tubulation and header mounting means, whereby assembly of the header in an envelope structure of an electric discharge device or similar device may be facilitated.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In carrying out the objects of my invention I provide a header construction comprising a pair of ceramic plates including patterns of registering apertures. A central aperture in, one of the plates has a metal exhaust tubulation extending therethrough and includes a flange disp sed betweenthe plates and bonded to the inner surfaces of both plates. The other apertures have portions of elongated conductive leads extending therethrough and 3,009,012 Patented Nov. 14, 1961 includes flanges disposed between the plates and bonded to the inner surfaces of both plates. A metal mounting flange includes an inwardly extending flange disposed between and brazed to the outer edges of both plates.

For a better understanding of my invention reference may be had to the drawing wherein:

FIGURE 1 is an enlarged side elevational view of an electric discharge device partially broken away to illustrate an embodiment of my invention incorporated therein; and

FIGURE 2 is an enlarged exploded perspective illustration of the elements and arrangement thereof whereby I obtain the form of my invention illustrated in FIG- URE 1.

Referring to the drawing, there is shown in FIGURE 1 an electric discharge device generally designated 1 and incorporating a header designated 2 and constructed in accordance with my invention. The device 1 in which I have shown my header can include a metallic envelope 3 containing a plurality of cooperating electrodes (not shown). These electrodes can be suitably mounted in the envelope and can be connected to and partially supported by tabs or leads generally designated 4. Electrical connections between the leads 4 and an external circuit are made through multiple rigid conductors or leads 5. In the art leads 5 are often referred to as pins. The leads 5 comprise parts of my header 2 and each includes an integral flange 6 formed thereon intermediate the ends. The flanges 6 are interposed or sandwiched between a pair of ceramic plates or disks 7. The disks 7 each include a pattern of aperture 10 of the type illustrated in FIGURE 2 and adapted for receiving the corresponding ends of the leads 5. Metallic bonds obtained in a manner to be described in detail hereinafter are provided between flanges 6 of the pins 5 and both of the ceramic disks 7 immediately about the edges of each of the apertures 10. Thus, the pins 5 are hermetically sealed between the disks 7 and are mutually insulated from each other. If desired, the flanged leads can be fabricated from separately formed pins and washers and these elements can be brazed together and made integral through the agency of the brazing alloy used to provide the metallic bonds between the metal lead elements and ceramic disks.

The header construction described to this point is assembled in the envelope 3 by means of a mounting ring 12. The ring 12 can be angular in section as shown, including a wall section 13 and an inwardly extending flange 14. The flange 14 is interposed or sandwiched between the ceramic disks 7 and is hermetically sealed by means of metallic bonds between the flange 14 and both the upper and lower disks 7 as at 15. The metallic bonds are restricted to the marginal or peripheral areas of the ceramic disks and are spaced from the flanges 6 on the pins and the metallic bonds between the flanges 6 and the ceramic disks and, thus, the mounting ring 12 is insulated from the other conductive elements of the header. The mounting ring 12 is adapted for being bonded to the envelope 3, as by a. bead weld 16, between the corresponding edges of the ring wall 13 and the edge of the opened end of the envelope.

Exhaust or gas filling of the envelope can beeffected through a metal tubulation 20 extending through a central aperture 21 in the lower one of the ceramic disks 7. A corresponding and registering aperture 21 in the upper disks provides communication between the interior of the device and the tubulation. The tubulation includes an outwardly extending flange 22 which is interposed or sandwiched between the ceramic disks and is hermetically sealed thereto in the region only immediately surrounding the apertures 21, as at 23. In the embodiment shown in FIGURE 1 the tubulation is tipped off or pinched closed as it would be after completion of an exhaust or gasfilling Operation.

Thus, the header 2 of FIGURE 1 is constructed to include a plurality of mutually insulated metallic members including rigid conductive leads or pins, an exhaust tubulation, and a mounting ring whereby mounting of the header in an envelope structure can be facilitated. Additionally, the outer portions of the leads or conductors 5 can be suflic-iently rigid so as to enable same to serve as the pins for insertion in the receptacles of a tube socket or, if desired, a tube base can be utilized with this structure wherein the pins 5 can be inserted in and electrically connected to tube prongs which, in turn, are adapted for insertion in the receptacles of a tube socket.

FIGURE 2 illustrates the elements and order of assembly of parts which I employ in obtaining my header construction as illustrated in FIGURE 1. As seen in FIG- URE 2, and as will be understood from the foregoing, two ceramic disks 7 are provided including patterns of apertures 10 and 21 which are adapted for being in register when the disks 7 are superposed. By use of any suitable metalizing technique such as that disclosed and claimed in US. Patent No. 2,667,427 of H. I. Nolte and assigned to the same assignee as the present invention, the upper surface of the lower disk 7 is metalized about the marginal edge of the disk, as at 25, about each of the apertures it), as at 2d, and about the edge of the aperture 22 in a manner not shown in FIGURE 2. The undersurface of the upper ceramic disk is identically metalized and, inasmuch as the various metal elements of the header must be mutually electrically insulated, the metalized areas 25 and 26 and the similar areas provided for use in bonding the tubulation are all mutually spaced thus to avoid any conductive current paths therebetween. In arriving at the finished header assembly 2 I fit a solder washer 27 on the upper and lower ends of each pin 5. Also, I fit similar but larger Washers 28 on the tubulation 20. The lower ends of the pins 5 and the tubulation 2% bearing the washers are then inserted in the apertures 10 and 21, respectively, of the lower disk 7. Thereafter, a still larger solder washer 29 corresponding in dimension to the marginal area of the disk is placed over the metalized surface on the lower disk and the mounting ring 12 is fitted thereover with the flange 14 in contact with the solder ring 29. Subsequently another washer 29 is placed on top of the flange 14 of the mounting ring and the upper disk 7 is put in place over the upper portions of the pins 5. The thus assembled arrangement is then brazed at approximately 1025 centigrade in a hydrogen furnace for a period of time sufficient to melt the solder washers 27, 28 and 29, thus to enable same to react with the metalized surfaces of the ceramic disks thereby to provide the metallic bonds between the flanges on the pins, tubulation and mounting ring and between these elements and both the upper and lower disks. In this manner the construction becomes a rigid vacuum-tight header assembly which is adapted for withstanding both high-frequency operation as well as high temperature operation and is also adapted for withstanding substantial vibration and thermal shock.

While I have shown and described a specific embodiment of my invention I do not desire my invention to be limited to the particular form shown and described, and I intend by the appended claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A vacuum-tight header construction comprising a plurality of superimposed ceramic plates including registering apertures, a metallic conductive element including portions extending through each of said apertures respectively and having an integral annular flange disposed between said plates, and a vacuum-tight ceramic-to-metal bond between said flange and each of said plates.

2. A vacuum-tight header construction comprising a plurality of superimposed ceramic plates including registering apertures, a metal exhaust tubulation extending through one of said apertures and having an integral annular flange disposed between said plates, and a vacuumtight cerarnic-to-metal bond between said flange and each of said plates.

3. A vacuum-tight header construction comprising a plurality of superimposed ceramic plates, a metal mounting ring having an integral inwardly extending annular flange disposed between the edges of said plates, and a vacuum-tight ceramic-to-metal bond between said flange and each of said plates.

4. A vacuum-tight header construction comprising a pair of superposed ceramic disks including patterns of registering apertures, each of said disks having metalized areas surrounding the apertures therein with said metalized areas being hermetically sealed to said disks and said areas on each of said disks being in mutually insulated spaced relation, a plurality of metal leads including portions extending through each of said apertures respectively and having annular integral flanges disposed between said disks and between corresponding metalized areas of said disks, and vacuum-tight metallic bonds between each said flanges and the corresponding metalized areas of each of said disks, and said bonds being confined to only the areas immediately about the edges of said apertures, whereby said leads are hermetically sealed in and to each of said disks in mutually insulated, spaced relation to each other.

5. A header vacuum-tight construction comprising a pair of superposed ceramic disks including patterns of registering apertures, each of said disks having metalized areas surrounding the apertures therein with said metalized areas on each disk being hermetically sealed thereto and in mutually spaced relation, a plurality of metal leads including portions extending through each of certain ones of said apertures respectively and having annular integral flanges disposed between said disks and between corresponding metalized areas of said disks, a metal exhaust tubulation extending through one of said apertures in one of said disks and having an integral annular flange disposed between said disks and between corresponding metalized areas of said disks, vacuum-tight metallic bonds between the corresponding metalized areas of each of said disks and each said flanges on said leads and said flange on said tubulation, and said bonds being confined to only the areas immediately about the edges of each of said apertures.

6. A vacuum-tight header construction comprising a pair of superposed ceramic disks including patterns of registering apertures, each of said disks having metalized areas surrounding the apertures therein and on the peripheral surfaces of said disks with said metalized areas on each disk being hermetically sealed to said disk and in mutually insulated spaced relation, a plurality of metal conductive leads including portions extending through each of certain ones of said apertures respectively and having annular integral flanges disposed between said disks and between corresponding metalized areas of said disks, a metal mounting ring including an inwardly extending flange disposed between said disks and between the metalized peripheral surfaces thereof, and vacuumtight metallic bonds between each said flanges and the corresponding metalized areas on said disks, said bonds all being in mutually insulated spaced relation.

7. A vacuum-tight header construction comprising a pair of superposed ceramic disks including patterns of registering apertures, each of said disks having metalized areas surrounding the apertures therein and on the peripheral surfaces of said disks with said metalized areas being hermetically sealed to said disks with said areas on each of said disks being in mutually insulated spaced relation, a plurality of metal conductive leads including portions extending through each of certain ones of said apertures respectively and having annular integral flanges disposed between said disks and between corresponding metalized areas of said disks, a metal tubulation extending through a centrally disposed aperture in one of said disks and having an annular integral flange disposed between said disks and between corresponding metalized areas of said disks, a metal mounting ring including an inwardly extending annular flange disposed between the metalized peripheral surfaces of said disks, vacuum-tight metallic bonds between each said flanges on said leads, tubulation and ring flange and the corresponding metalized area on each of said disks, and said bonds all being in mutually insulated spaced relation, whereby said leads, tubulation and mounting ring are hermetically sealed between and to each of said disks in mutually insulated, spaced relation.

References Cited in the file of this patent UNITED STATES PATENTS Beggs Oct. 3, 1939 Bahls Aug. 6, 1940 Bishop June 3, 1941 Miller Feb. 2, 1943 Herzog July 26, 1949 Glickman et al Dec. 4, 1951 Retzer Aug. 30, 1955 Sorg et a1 Sept. 27, 1955 FOREIGN PATENTS Great Britain Mar. 13, 1957 UNITED STATES PATENT. OFFICE CERTIFICATE OF CORRECTION Patent No, 3 009 012 November 14 1961 James Po Polese above numbered patat the said Letters Patent should read as corrected below.

Column 4, 'line 3O for "header vacuuzm tight read vacuum-tight header Signed and sealed this 15th day of Megy 19620 (SEAL) Attest:

ERNEST W. SWIDER DAVID LADD Attesting Officer I Commissioner of Patents UNITED STATES PATENT. OFFICE CERTIFICATE OF CORRECTION Patent No. 3,009,012 November 14, 1961 James P. P'olese It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below. 4

Column 4, line 30, for

"header vacuum==tight read vacuum-tight header Signed and sealed this 15th day of May 1962,

(SEAL) Attest:

ERNEST W. SWIDER Commissioner of Patents

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