WO2016166564A1

WO2016166564A1 - Tester having a magnifying optical instrument

Info

Publication number: WO2016166564A1
Application number: PCT/IB2015/000668
Authority: WO
Inventors: Ralph Krippendorf; Frank-Michael Werner; Sebastian Giessmann
Original assignee: Cascade Microtech, Inc.
Priority date: 2015-04-14
Filing date: 2015-04-14
Publication date: 2016-10-20

Abstract

The invention relates to a tester for inspecting or testing microelectronic components (27), which comprises a holding device (26) for the component (27), at least one probe (28), and a magnifying optical instrument (23, 23'). In order to enlarge the distance between the microelectronic component to be observed and the optical instrument and thus the space available for the probes, the invention proposes arranging a refraction element (3) for refracting the light beams passing from the component into the optical instrument in the optical path of the optical instrument between the component and the optical instrument at least during the contacting and/or excitation of the component, the index of refraction, the shape, and the size of the refraction element (3) being selected in such a way that the focal point of the light beams passing through the refraction element (3) lies outside of the refraction element.

Description

Prober with a magnifying optical instrument

The invention relates generally to probes for testing or testing microelectronic devices.

These are test stations in which the

Components, referred to as test substrate, in their production and development in various

Manufacturing stages are subjected to different tests and tests. For this purpose, the test substrates are contacted or excited in any way and evaluated the response signal. The contacting or excitation can be done for example electrically, optically or electrostatically or with a combination of different

Contacts or suggestions. Since testing and testing can be done under a wide range of environmental conditions, the test substrates and probes are also optionally housed in housings.

Such a prober generally comprises a holder device for holding at least one component and at least one probe for its contacting and / or excitation. Of the

Concept of the probe is intended here generally for both

Contacting as well as for the suggestion with the

different alternative ways are used.

The invention particularly relates to a prober with a magnifying optical instrument for imaging the

Position of the probe or probes relative to the device. It will be understood that, for probes larger than the field of view of the optical instrument, only the part of the probe or probes will be imaged whose position relative to the device will be relevant for contacting and / or excitation is.

By means of the magnifying optical instrument, e.g. Magnifying glasses, cameras or microscopes, the angle of vision, under which an object is seen, is enlarged in comparison to the observation without the optical instrument.

If optical instruments, such as microscopes, are used, the possible position of the lens of the

respective optical instrument determined by the

Working distance, that is the distance between the lens and the focal plane, which functionally due to

observing object must be positioned. Of the

Working distance is usually very low when high resolution is needed. This is especially true in the

Microelectronics, biotechnology or other departments are required, whose object details are in the micrometer range. In addition, it is often necessary to manipulate or move the objects in any way during the observation, so that the possible position of the optical

Instruments is also limited by the space required for it.

As the density of integration in microelectronics increases, the structures of the test substrates, and thus also the test probes, become steadily smaller and denser. As a result, the resolution of the optical element for observing the contact must be higher, which is usually associated with shorter working distances. This is accompanied by the available space for the from above the

respective component supplied probes smaller and smaller.

Probers with optical windows are also known. These are used regularly when required by, for example, environmental conditions, spatial observation by persons or optical instruments such as observation devices or optical sensors to separate from the object to be observed. In such probes, apertures or case members or the like as an optical window have a plane-parallel plate which is transparent to the wavelength used or the wavelength range used for observation.

For example, optical windows in pressure chambers or media chambers are used to look from the outside into the closed chamber to the object to be observed, which is exposed in the chamber defined environmental conditions. The properties of an optical window are matched to the particular application of the device. For pressure chambers, the optical window must ensure the tightness of the chamber and have a strength adapted to the pressure differences.

Also the requirements for the chemical and mechanical resistance, the thermal behavior and the

Installation situation in the respective element of the device are taken into account. Of primary interest are the optical properties and the realizable field of view, that is the possible size of the window, which depends, among other things, on the weight of the optical window, the available space in the device and the

Depend on pressure conditions.

A typical material for optical windows, which only serves to observe an object lying behind the optical window, is optical glass, which by means of targeted chemical additives in its optical properties

is set. Known here is e.g. BK7 Glass, which is transparent in the wavelength range of 330 - 2100 nm and has a refractive index of 1.5164 at 588 nm. Other materials may include quartz glass, sapphire, quinicum fluoride,

Zinc selenide or magnesium fluoride. For example, quartz glass is used at wavelengths below 300 nm (deep ultraviolet - DUV) for laser applications and zinc selenide for Infrared applications used.

Optical windows are mostly used without the

To change the optical path so that the design of the optical window, the thickness of the plane-parallel plate is generally neglected. Since this is usually small in relation to the total length of the optical

Systems, in most cases, this simplifying assumption is justified.

In FIGS. 1A and 1B, the situation is illustrated using the example of a housing cover of a prober with an optical window, in which the optical window 1, consisting of a plane-parallel plate 2, by means of suitable

Mounts mounted flush with the housing cover 22 (FIG. 1A). Alternatively, the optical window 1 can be lowered with respect to the surrounding level of the housing cover 22 (FIG. 1B), but only in the immediate contacting area.

Thus, the optical window 1 is placed as close as possible to the test substrate (not shown), but the location, type and shape of the optical window are clearly limited by the probes (not shown) to be placed between the optical window and the test substrate. Also, the handling of the objects to be observed, such as

Test substrate and probes, during placement and

Operation is difficult due to the limited space.

The same applies in the event that an optical

Instrument, such as a microscope, without lying between the housing cover with optical window, is driven close to the device to image its structures dissolve. Also in this case, the optical limits

Instrument due to its usual dimensions, the space above the device in particular in that area in which the probes are to be placed, to an unacceptable extent. It is an object of the invention to provide a prober with which the distance between the microelectronic device to be observed and the optical instrument can be increased without significantly reducing the quality of observation of the object by means of the optical instrument known from the prior art. In this way, the space available for the probes, their placement as well as their manipulation should be increased.

The term light in the description of the invention encompasses the wavelength range of the visible radiation assumed to be between 380 and 780 nm and, moreover, in a broader sense also the wavelength ranges for infrared, ultraviolet and x-ray radiation.

The sampler according to the invention should be further variably adaptable to different conditions of use, which are particularly suitable with regard to the geometric conditions of the sampler itself, e.g. the use of one or none

Housing with an optical window, the optical instrument used and the required resolutions, the space requirements of the probes, the wavelengths used and the atmospheric surrounding the device

Conditions can differ.

The optical effect of the refraction element is based on its size and shape and the use of a material with a refractive index selected in relation to the adjacent surrounding medium. As a surrounding medium here are all possible test atmospheres to be understood, which come into consideration for testing and testing of components and also include vacuum.

Due to the size and shape of the refraction element and its refractive index, which of the refractive index of the da on refraction element adjacent, surrounding medium deviates, results in the Lichtein- and

Light exit surfaces, the advantageous consequence of refractions and thus the advantageous beam path through the

Refraction element. Due to the relations of

Refractive indices, the light beam is refracted during its passage through the refraction element such that the focal length of the magnifying optical instrument

is extended.

When passing the first, the optical instrument

The closest interface of the refraction element, the light entry surface, due to the transition into a more dense optical medium with a higher refractive index refraction to the surface normal of this interface out. The ratio of angles of incoming to outgoing steel is known to be determined by Snell's law of refraction. Thereafter, a beam in the transition from an optically thinner into a more dense optical medium

Surface normal of the interface broken down. That is, the angle of reflection is smaller than the angle of incidence, both measured to the normal of the interface. In reverse

Beam passage is the angle of failure greater than that

Angle of incidence. Consequently, the ratio of

Refractive indices of the refraction element to the value of the surrounding medium, the variation of the focal length change. With the largest possible refractive index of the

Refraction element, z. B. of sapphire, the

Focal length extension to be maximized.

As a refraction element, for example, glasses

used. The surrounding medium is regularly air or an inert gas or a test gas or vacuum, so that the required for the extension of the focal length beam path can be achieved. But also for the rest due to the

Transparency requirement eligible materials of the refraction element is the required ratio of the refractive indices feasible and suitable Combinations can be optimized. The beam path is to be determined for the different material combinations by computationally known methods.

In addition to the material of the refraction element is the

Extension of the focal length of the optical instrument also variable by means of the thickness of the refraction element. In the descriptions of the figures, the beam paths are explained in detail using various examples.

As a result, it is possible to also use high-resolution optical instruments and to extend their focal length to the object without bringing them close to the object, as is known in the art. The space thus obtained laterally of the refraction element is available for a required manipulation of the object or installations for contacting or excitation under the optical window or superstructures on the wall thereof laterally, wherein it is not necessary that the refraction element cover the entire surface of the refracting element

plane parallel plate occupies. The arrangement of the refracting element adjacent to one of the flat surfaces of the plate implies that the

Refraction element can be arranged either on the optical instrument or the object to be observed facing side of the plate. That depends on where more space is needed directly adjacent to the window. If the refraction element lies on the object side, there is room

created between the object and the wall or

similar holding the optical window or between the object and the plane-parallel plate, if larger, than the refraction element. Is that right

Refraction element, however, on the side of the optical instrument, for example, at less favorable

geometric design of the wall or similar or constructions on this the optical instrument nevertheless close enough to be brought to the optical window to focus on the object can.

Depending on the position of the refraction element, for example, structures of an electronic component can be observed when the optical window in the housing cover

is arranged and is looked at from above on the device. Even a lateral observation is possible

for example, details of the height setting of the

Test substrates or probes. In this case, the optical window is arranged in a side wall of the housing. The terms "top" and "side" are defined from the perspective of the substrate, with "top" to the

describes contacting surface.

The view from the top of the device is made regularly during the contacting of the device by means of

Probes. In this case, the refraction element is arranged inside the prober. Because of its lower

Dimensions compared to the plane-parallel plate and its support in the housing wall space is obtained laterally of the refraction element, which is useful for the probes and their brackets, manipulators and contacts. The probes are known to protrude from the side of the observation area arranged brackets cantilever-like in the central observation area and thus directly under the refraction element.

The described gain in space can be enhanced if the refraction element is adapted to the beam path and, according to one embodiment, is designed as a pyramid or a truncated cone, with towards the component

increasing or decreasing cross-section. It is advantageous that the angle of the lateral surfaces of the stump equal to or greater than the opening angle of the broken

Beam path is within the refraction element and that the cross section is dimensioned so that the Beam path through the entire refraction element extends to the object zugerichtet lying surface.

In one embodiment, the refraction element is combined with the plane-parallel plate of an optical window. In this embodiment, the refraction element has a plane-parallel or plano-convex or plano-concave shape, so that it can be arranged with its at least one planar surface adjacent to one of the planar surfaces of the plane-parallel plate. It is self-evident that the plane-parallel plate is transparent at least in a part of that wavelength range in which the refraction element also permits the observation.

Such an embodiment also includes the optical window in the advantageous arrangement of optical instrument and refraction element, so that the optical window in a preferred installation space for the task

providing greater distance to the probe tips can be arranged.

The term combination of the two elements includes various embodiments. So they can be monolithic or multi-part design. The separate elements can be firmly connected to each other or held adjacent to each other by means of suitable holding means.

The term "adjacent to one another" characterizes the geometric assignment of the two elements in such a way that no further optically active solid is arranged between the two

Refraction element can thus in different

Embodiments with a distance, that is, with a "free space" or be arranged without a distance next to each other, wherein a gap, as set forth below for an embodiment, free-standing or may be filled with an immersion medium Gap can be constructive due to the holder or merely serve the arrangement of an immersion medium and will therefore always be small in relation to the thickness of the refraction element.

This variability in the connection of the elements and their arrangement to each other allows a versatile adaptation of the shape of both elements to the various

Conditions .

By means of the structure of optical window with

Refraction element and the optical properties can be influenced. Is it designed as a compact, one-piece component, so that both components are made of the same material and are distinguishable only in terms of their geometry and or their installation situation, the optical losses at interfaces

be minimized. A permanent or detachable connection of both elements is in terms of joining method and the joining material for defined applications

configured. For example, in vacuum applications, the desorption behavior of the joining material and the

Pressure load to consider. With detachable connections, variable modifications are possible at any time.

Depending on the ratio of refractive indices of

plane-parallel plate and the refraction element consequently the beam path within the plane-parallel plate in the refraction element is continued (same optical density of both materials) or further to the surface normal (optically denser refraction element) or again broken away from this (optically less dense refraction element).

A gap between the two elements is either with a refractive index of exactly one for vacuum or about one for many gases or with a matched one Refractive index of an immersion medium, as will be described below.

The described minimization of the lateral space requirement for the refraction element makes it possible for a larger plane-parallel plate relative to the refraction element that the observation of the object can be achieved both by the combination of

plane-parallel plate and refraction element as well as can be done solely by the plane-parallel plate. In the latter case, the observation takes place past the refraction element, either by the optical instrument or visually by the eye of the observer, or both. This puts the optical window, except the possibility of visual

Viewing, two focal lengths available for an optical instrument, provided that the vote of both areas of the optical window with the optical instrument was made as stated above accordingly.

In a two-part design of the optical window, it is possible to perform the interface between the plane-parallel plate and the refractive element anti-reflection. Reflections are provided by coatings having such an optical thickness which causes destructive interference or by diffuse reflection

Surface structures known. Such an embodiment includes that the incident and failure surfaces of the optical window or the refractor element, the latter also in the sole use of a refractor element, are non-reflective.

The refraction element can, as described above, be designed as a plane-parallel element or on its side facing away from the plane-parallel plate and / or facing

Surface have a convex or concave shape. In order to

affects the refraction element over the

Focal length extension out the beam path. This part of the imaging optics is thus in immediate Near the object and thus allows, for example, a higher

Enlargement. Alternatively, the refraction element having a similar effect may have separate, combinable optical elements such as lenses or filters for variable adaptation to the respective ones

Requirements for the optical window.

An improvement in the optical performance of the invention combined with a refractory optical window is further possible by the use of an immersion medium, which is set with their refractive index specifically so that it represents a steady as possible intermediary between the two optical elements which are interconnected by the medium , Such

Immersion media are used in liquid form, for example in immersion objectives in which the

Immersion liquid the space between a

Lens and the optical window fills. Additionally or alternatively, an immersion medium can also be arranged between the plane-parallel plate and the refraction element.

The above-mentioned options of combining the two elements allow various embodiments of the invention

optical window according to the invention, in which a

Adjustment of refractive indices by means of a

Immersion medium between the two elements takes place. If both elements are connected to each other by gluing, adhesives can be selected that have a suitable adhesive

Have refractive index and serve as immersion medium.

In particular, when both elements or one of them are made of glass, adhesives are available whose refractive index is in the vicinity of the values of the glasses. Alternatively, in the case of a gap or in a cavity between the two elements, the latter may be filled at least in one section with a suitable immersion medium. With a suitable seal of the gap or the cavity Immersion liquids are also applicable.

The optical instrument may be a microscope in one embodiment of the prober. These are mostly through

Replacement parts or additional components variable, so that its optical parameters can be adjusted to special properties of the optical window. This concerns, for example, the lens, apertures, filters and other components. Thus, aberrations, z. B.

Color fringes, which are caused by the extended beam path in the optical window, through which the design of the lens are compensated.

In a prober, you can also do other positions

Refractor elements or when used with housing also inventive optical window can be used.

For example, in at least one of his

Housing walls are used an optical window according to one of the embodiments described above.

The invention will be described below with reference to

Embodiments will be explained in more detail. The

accompanying drawings show in

1A, 1B optical windows in a housing cover according to the prior art,

2A, 2B optical window according to the invention in a housing cover, Fig. 3A - Fig. 3C beam path of a lens without and with refraction element and also with inventive optical window,

FIGS. 4A-4F show embodiments of the refracting element according to the invention without and with optical probes

Windows and

5 shows a prober with embodiments of the inventive optical window.

The description of the optical window 1 according to the invention is given by way of example but not limitation with respect to a prober having a housing. Unless in the figures

Components are identified by the same reference numerals, the same or analogous components are shown and described.

FIGS. 2A and 2B illustrate optical according to the invention

Window 1, which analogous to the installation situations in Figs. 1A and 1B, according to the prior art, in a

Housing cover 22 are arranged. The optical window according to FIG. 2A is mounted in the housing cover 22 almost level with respect to its uppermost surface. The circular optical window 1 comprises a planar retaining ring 4 for mounting the optical window 1 in the housing cover 22. The circular plane-parallel plate 2 is fastened by means of screws 11 to the hairline 4. On the underside 5 of the plane-parallel plate 2 concentrically a plane-parallel refraction element 3 is fixed by gluing. The

Refraction element 3 has a conical shape with decreasing cross-section.

The optical window 1 in Fig. 2B differs from that in Fig. 2A by a downwardly in several stages

stepped retaining ring 4, so that optical window 1 is lowered into the housing cover 22. The optical window 1 of this embodiment is embodied in one piece, so that the underlying refraction element 3 is connected to the plane-parallel plate 2 without transition. A

physical separation of the two elements is not possible here, but should be retained for better understanding. An objective separation into two separate elements is alternatively also in such a

Embodiment possible. The plane-parallel plate 2 and refraction element 3 form a cylinder, with suitable Means or structuring of the cylinder are provided for its installation. The illustrated ratios of

Diameter of plane-parallel plate 2 and

Refraction element 3 are exemplary only. Other conditions are possible.

The embodiments of FIG. 2A and FIG. 2B illustrate how installation space around the refraction element 3 is obtained by supplementing the refraction element 3, since without this, the housing cover 22 or at least areas of the retaining ring 4 would have to be further lowered.

FIGS. 3A to 3C illustrate those with a

refraction element 3 according to the invention (FIG. 3B) and in combination with an optical window 1 (FIG. 3C)

achievable extension of the focal length f compared to the prior art (FIG. 3A). The focal length of the

optical instrument 23, shown here is simplified only a lens, for example, a microscope, is determined by its optical parameters and in Fig. 3A based on the focused optical path of the outer

Light beams 6 schematically and thus presented without claim to scale illustration.

In Fig. 3B, a cone-shaped refraction element 3 by means of gluing, which in this embodiment, the

Holding means 9, in a suitable holder

inserted. As a result of the arrangement of the refractor element 3, there is a beam offset due to the refraction at its two boundary surfaces, specifically at the upper entrance surface and the lower exit surface of the plane-parallel

Refraction element 3. The assignment of the designations "entrance surface" and "exit surface" follows here, and in the following

Contemplation, the direction of propagation of the beam path in the direction from top to bottom, such as the Light beams of a coaxial illumination, which have their origin at the top, in the optical instrument 23.

First, the light beam 6 is refracted toward the surface normal of the refraction element 3, which in the exemplary embodiment runs parallel to the optical axis 7 of the optical instrument 23. With the exit of the beam from the refraction element 3, a refraction with a larger exit angle and thus a focus on a

Focal point having a distance a to the focal length of Fig. 3A. The beam offset visible in FIG. 3B

results from the steeper course of the beam within the refraction element 3 due to its greater optical density compared to the optical density of the surrounding medium, for example air.

By adding the plane-parallel plate 2 of an optical window 1 of FIG. 3C, the same becomes

Extension a of the focal length is achieved if the total height of refraction element 3 and plane-parallel plate 2 remains the same and the refractive index coincides. Due to the latter embodiment, there is no significant refraction at the interface between the plane-parallel plate 2 and the refraction element 3. Refraction element 3 and plane-parallel plate 2 exist in the

Exemplary embodiments of borosilicate glass BK7. The geometry and material choices for both elements allow you to achieve different focal lengths or focal lengths with more space.

In FIGS. 4A to 4F, various ones are shown

Embodiments of the inventive refractive element 3 by way of example with and without optical window 1 with the

Lens of an optical instrument 23 and the focused beam path of the light beams 6 shown schematically. The optical axes 7 of the optical instrument 23 and the refraction element 3 fall, as already in FIGS. 3B and Fig. 3C together.

4A and 4B each represent an optical window 1, the plane-parallel plate 2 with a conical

extending refraction element 3 by means of a

Adhesive layer 8 is connected. The refraction element 3 has a plano-convex shape (FIG. 4A) or a plano-concave shape (FIG. 4B), with the different beam path achievable thereby for various applications. In both

Embodiments, the refraction elements 3 are each connected to the plane side with the plane-parallel plate 2.

The embodiments of FIGS. 4C and 4D differ from those of FIGS. 4A and 4B in that the refraction elements 3 are mounted plane-parallel and by means of holding means 9 on the plane-parallel plate 2. The use of retaining means 9 makes it possible to make a gap 10 between both elements (Figure 4C) filled with an immersion medium. In contrast, the holding means 9 in Fig. 4D holds the plane-parallel plate 2 and the refraction element 3 directly adjacent to each other.

FIG. 4E illustrates a variant without an optical window, in which, for example, a refraction element 3 with concave light entry surface and convex light exit surface is used. Due to the concave light entry surface is a parallel in the embodiment shown

Beam path achieved by the refraction element 3, so that by means of its height, the focal length f very well

is adjustable. Alternatively, by means of a less-convex, ie less curved entrance surface

convergent, so towards the bottom towards the optical axis 7 tapering toward the beam can be achieved. Alternatively, by means of a more convex, ie more curved entrance surface, a divergent, that is downwards

divergent beam path can be achieved. The optical window 1 of Fig. 4F has a plane-parallel plate 2 which is substantially larger than that

As a result, the optical instrument 23 can be moved by means of its holder (not shown) into an area (represented by a double arrow), in which the beam path does not extend through the refraction element 3, but only through the plane-parallel plate 2. Corresponding to the two positions of the optical instrument, the reference numerals for the optical instrument and its beam path are denoted by 23 and 23 ^Λ respectively, and 6 and 6 ^Λ respectively. From the two positions results in a different light path and thus a different beam offset so that the optical instrument and f f ^Λ can be focused on two different focal lengths. Alternatively or additionally, in the second position or from a further, third position, an observation without optical

Instrument (represented by an icon of a human eye). FIG. 5 illustrates a prober 20 comprising a housing 21. The housing 21 is formed by a housing bottom 25, housing side walls 24 and the housing 21 closing housing cover 22. In the housing 21 are a

Holder device 26, also referred to as Chuck, for

Holder of a device 27, in the embodiment of a wafer arranged. The device 27 is mechanically and electrically by a plurality of probes 28

contacted.

The cantilevered probes 28 are mounted on a probe holder plate 29 by means of probe holders 31 and protrude with the probe tips 32 at the free ends through a central opening 30 of the probe holder plate 29 onto the component 27. The probe holders 31 serve to hold the probes 28 and their electrical contacting as well one

Fine positioning of the probe tips 32 relative to each other as well as to the component 27. Alternatively, the probe tips 32 may also be mounted on so-called probe cards (not shown), which in turn directly on the

Probe holder plate is mounted. Such probe cards are known for testing complex devices 27 in which many similar devices 27 must be contacted with a large number of probes.

By means of the chuck 26, the device 27 can be moved in the prober 20 relative to the probes 28 in the room to make the contact.

About the probe tips 32 and the central opening 30 of the probe holder plate 29 is in the housing cover 22 a

arranged according to the invention optical window 1, which is mounted by means of its retaining ring 4 on the housing cover 22. The retainer ring is as described in Fig.2B in

Stepped toward the component 27, so that the optical window 1 is lowered relative to the level of the housing cover. The optical window comprises a pan-parallel plate 2, which has a plane-parallel, conical

Refraction element 3 is connected by gluing. The

Refraction element 3 is located inside the housing above the probe tips 32. Due to the significantly lower in comparison to the lowering of the housing cover 22 lateral extent of the refraction element 3, the cantilevers of the probes 28 laterally of the refraction element 3 to the probe holders 31 extend and the refraction element 3 at the same time protrude to a very small distance to the probe tips 32.

Alternatively, the optical window may also have other of the embodiments described above, as far as they are suitable for the respective requirements.

Directly above the optical window 1 projects an optical instrument 23, here the objective of a microscope, as far as in the depression formed by the retaining ring 4 and the optical window 1 that the smallest possible distance

between the lens and the optical window 1

is set. In the illustrated embodiment, an optional further inventive optical window 1 is arranged in a passage 33 in a housing side wall 24. This likewise comprises a pan-parallel plate 2 which is provided with a plane-parallel, for example cylindrical

Refraction element 3 is connected by gluing. Also, the second optical window 1 may have an alternative design. The refraction element 3 of this second optical window 1 is arranged outside the housing 21, so that it is the depth of lateral structures on the

Housing side wall 24, shown schematically by a larger wall thickness, bridged. Immediately before this optical window 1, a further optical instrument 23, for example a camera, is arranged

For example, the detection of the exact contacting of the probe tips 32 on the device 27 is used.

The embodiment of FIG. 5 may also be formed without housing 21 (not shown). In this case, the refraction element 3 would without optical window 1 by means of suitable brackets, for example, on the

Probe support plate 29 are mounted in position, so that the optical instrument 23 instead of in a slightly lower position than in Fig. 5 shown far enough away from the probe tips 32 and yet the probe tips 32 in the required

Resolution can be observed. Reference character list optical window

plane parallel plate

refraction element

retaining ring

bottom

beam of light

optical axis

adhesive layer

holding means

gap

screw

Prober

casing

housing cover

optical instrument

Housing sidewall

caseback

Holding device, Chuck

module

probes

Probe holder plate

central opening

probe holder

probe tips

passage

focal length

Extension of the focal length

Claims

1. Prober for testing or testing of microelectronic components (27), which has a holder device (26) for holding at least one component (27), at least one probe (28) for contacting and / or exciting it and a magnifying optical instrument (23, 23 ^Λ ) for imaging the position of the probe (8) relative to the component (27), characterized

- That the prober (20) is an optical element for

Refraction of the optical beam to the component (27) extending light beams (6), hereinafter referred to as refraction element (3) comprises, which at least during the contacting and / or excitation of the device (27) in the optical path of the optical instrument (23, 23 ^Λ ) between the component (27) and the optical instrument (23, 23 ^Λ ) is to be arranged, - that the refraction element (3) consists of a body of a dielectric material which is transparent in a predefined wavelength range,

- That the body of the refraction element (3) comprises two opposing refractive surfaces for refraction of the optical instrument (23, 23 ^Λ ) to the component (27) extending light beams (6) which are plane-parallel to each other or of which at least one convex or has concave curvature,

- That the material of the refraction element (3) has a refractive index which is greater than that Refractive index of the adjacent to the refraction element (3) surrounding medium and

That the refractive index, the shape and size of the

Refraction element (3) are chosen so that the focal point of the light passing through the refraction element (3) light rays (6) outside the

Refraction element (3) is located.

2. Prober according to claim 1, characterized

characterized in - that the prober (20) comprises a housing (21), wherein in the housing (21) the holding device (26) and the probe (28) are arranged,

- That the housing (21) in at least one of his

Housing has an optical window (1), which in an optical path of the optical

Instruments (23, 23 ^Λ ) is arranged and a

comprising plane-parallel plate (2) made of a dielectric material,

- which at least in part of the predefined

Wavelength range of Refraktioselements (3) is transparent and has a refractive index which is greater than the refractive index of the adjacent surrounding medium,

- And that the refraction element (3) has a plane-parallel or plano-convex or plano-concave shape and is arranged with its flat surface adjacent to the plane-parallel plate (2).

3. Prober according to claim 2, characterized

in that the refraction element (3) is connected to the plane-parallel plate (2) or both detachably directly adjoining one another or side by side with one another Space (10) between the adjacent surfaces

are arranged.

4. Prober according to one of claims 2 or 3, characterized in that the refraction element (3) is smaller in such an extent than the plane-parallel

Plate (2), which allows observation by the plane-parallel plate (2) both by the refraction element (3) and on the refraction element (3) over.

5. Prober according to one of claims 2 to 4, characterized in that an interface between the plane-parallel plate (2) and the refraction element (3) is formed anti-reflective.

6. Prober according to one of claims 2 to 5, characterized in that between the plane-parallel plate (2) and the refraction element (3) an immersion medium is arranged.

7. Prober according to one of claims 2 to 6, characterized in that the refraction element (3) within the housing (21) over the probe tips (32) of the probes (28) is arranged.

8. Prober according to one of the preceding claims,

characterized in that the refraction element (3) is a cylinder or a pyramid or a

Truncated cone with increasing towards the component or

decreasing cross-section.

9. Prober according to one of the preceding claims,

characterized in that the optical

Instrument (23, 23 ^Λ ) is a microscope and the microscope is an optical element to compensate for a through the

Refraction element (3) caused optical error includes.