WO2003048788A1

WO2003048788A1 - Contact structure and production method thereof and probe contact assembly using same

Info

Publication number: WO2003048788A1
Application number: PCT/JP2002/012508
Authority: WO
Inventors: Yu Zhou; David Yu; Robert Edward Aldaz; Theodore A. Khoury
Original assignee: Advantest Corporation
Priority date: 2001-12-03
Filing date: 2002-11-29
Publication date: 2003-06-12
Also published as: JP2005512063A; KR100924623B1; KR20040070199A; TW200301360A; KR20090026815A; KR100888128B1

Abstract

A contact structure for establishing electrical connection with contact targets. The contact structure is formed of a contactor carrier and a plurality of contactors. The contactor carrier includes a sliding plate for locking the contactors on the contactor carrier. The contactor has an upper end having a cut-out to engage with the sliding plate, a lower end oriented in a direction opposite to the upper end and functions as a contact point for electrical connection with a contact target, and a diagonal beam portion provided between the upper end and the lower end to function as a spring. In another aspect, the contactors are first mounted on a contactor adapter and the contactor adapters are attached to the contactor carrier.

Description

DESCRIPTION

CONTACT STRUCTURE AND PRODUCTION METHOD THEREOF AND PROBE CONTACT ASSEMBLY USING SAME

Field of the Invention This invention relates to a contact structure and a production method thereof and a probe contact assembly using the contact structure, and more particularly, to a contact structure having a large number of contactors in a vertical direction and to a method for producing such a large number of contactors on a semiconductor wafer in a horizonal direction and removing the contactors from the wafer to be mounted on a substrate in a vertical direction to form the contact structure such as a contact probe assembly, probe card, IC chip, or other contact mechanism.

'■ Background of the Invention

In testing high density and high speed electrical devices such as LSI and VLSI circuits, a high performance contact structure such as a probe card having a large number of contactors must be used. In other applications, contact structures may be used for IC packages as IC leads.

The present invention is directed to a structure and production process of such contact structures for use in testing and burning-in LSI and VLSI chips, semiconductor wafers and dice, packaged semiconductor devices , printed circuit boards and the like. The present invention can also be applied to other purposes such as forming leads or terminal pins of IC chips, IC packages or other electronic devices. However, for the simplicity and convenience of explanation, the present invention is described mainly with respect to the semiconductor wafer testing.

In the case where semiconductor devices to be tested are in the form of a semiconductor wafer, a semiconductor test system such as an IC tester is usually connected to a substrate handler, such as an automatic wafer prober, to automatically test the semiconductor wafer. Such an example is shown in Figure 1 in which a semiconductor test system has a test head 100 which is ordinarily in a separate housing and electrically connected to the test system with a bundle of cables 110. The test head 100 and a substrate handler 400 are mechanically as well as electrically connected through an interface component 140 with one another with the aid of a manipulator 500 which is driven by a motor 510. The semiconductor wafers to be tested are automatically provided to a test position of the test head 100 by the substrate handler 400.

On the test head 100, the semiconductor wafer to be tested is provided with test signals generated by the semiconductor test system. The resultant output signals from the semiconductor wafer under test (IC circuits formed on the semiconductor wafer) are transmitted to the semiconductor test system. In the semiconductor test system, the output signals from the wafer are compared with expected data to determine whether the IC circuits on the semiconductor wafer function correctly or not .

Referring to Figures 1 and 2 , the test head 100 and the substrate handler 400 are connected through an interface component 140 consisting of a performance board 120, coaxial cables, pόgo-pins and connectors. The performance board 120 is a printed circuit board having circuit connections unique to electrical footprints of the test head 100. The test head 100 includes a large number of printed circuit boards 150 which correspond to the number of test channels (test pins) of the semiconductor test system. Each of the printed circuit boards 150 has a connector 160 to receive a corresponding contact terminal 121 mounted on the performance board 120. A "frog" ring (pogo-pin block) 130 is connected to the performance board 120 to accurately determine the contact position relative to the substrate handler 400. The frog ring 130 has a large number of contact pins 141, such as ZIF connectors or pogo-pins, connected to contact terminals 121, through coaxial cables 124.

As shown in Figure 2, the test head 100 is positioned over the substrate handler 400 and connected to the substrate handler through the interface component 140. In the substrate handler 400, a semiconductor wafer 300 to be tested is mounted on a chuck 180. In this example, a probe card 170 is provided above the semiconductor wafer 300 to be tested. The probe card 170 has a large number of probe contactors (such as cantilevers or needles) 190 to contact with contact targets such as circuit terminals or pads in the IC circuits on the semiconductor wafer 300 under test. Electrodes (contact pads) of the probe card 170 are electrically connected to the contact pins 141 provided on the frog ring 130. The contact pins 141 are also connected to the contact terminals 121 of the performance board 120 through the coaxial cables 124 where each contact terminal 121 is connected to the corresponding printed circuit board 150 of the test head 100. Further, the printed circuit boards 150 are connected to the semiconductor test system through the cable 110 having, for example, several hundreds of inner cables.

Under this arrangement, the probe contactors (needles) 190 contact the surface (contact target) of the semiconductor wafer 300 on the chuck 180 to apply test signals to the semiconductor wafer 300 and receive the resultant output signals from the wafer 300. As noted above, the resultant output signals from the semiconductor wafer 300 under test are compared with the expected data. generated by the semiconductor test system to determine whether the IC circuits on the semiconductor wafer 300 performs properly. Figure 3 is a bottom view of the probe card 170 of

Figure 2. '^■' In this example, the probe card 170 has an epoxy ring on which a plurality of probe contactors 190 called needles or cantilevers are mounted. When the chuck 180 mounting the semiconductor wafer 300 moves upward in Figure 2, the tips of the contactors 190 contact the pads or bumps (contact targets) on the wafer 300. The ends of the needles 190 are connected to wires 194 which are further connected to transmission lines (not shown) formed on the probe card 170. The transmission lines are connected to a plurality of electrodes (contact pads) 197 which are in communication with the pogo pins 141 of Figure 2.

Typically, the probe card 170 is structured by a multilayer of polyimide substrates having ground planes, power planes , signal transmission lines on many layers . As is well known¹ in the art, each of the signal transmission lines is designed to have a characteristic impedance such as 50 ohms by balancing the distributed parameters, i.e., dielectric constant and magnetic permeability of the polyimidei," inductances and capacitances of the signal paths within the probe card 170. Thus, the signal lines are impedance ' matched establishing a high frequency transmission bandwidth to the wafer 300 for supplying currents in a steady state as well as high current peaks generated by the device's outputs switching in a transient state. For removing noise, capacitors 193 and 195 are provided on the probe card between the power and ground planes .

An equivalent circuit of the probe card 170 is shown in Figure 4. ' As shown in Figures 4A and 4B, the signal transmission line on the probe card 170 extends from the electrode 197, the strip (impedance matched) line 196, the wire 194, to the contactor (needle) 190. Since the wire 194 and contactor 190 are not impedance matched, these portions are deemed as an inductor L in the high frequency band as shown in Figure 4C. Because of the overall length of the wire 194 and contactor 190 is around 20-30mm, significant limitations will be resulted from the inductor when testing a high frequency performance of a device under test.

Other factors which limit the frequency bandwidth in the probe card 170 reside in the power and ground contactors shown in Figures 4D and 4E. If the power line can provide large enough currents to the device under test, it will not seriously limit the operational bandwidth in testing the device.. However, because the series connected wire 194 and needle 190 for supplying the power (Figure 4D) as well as the series connected wire 194 and contactor (needle) 190 for grounding the power and signals (Figure 4E) are equivalent to inductors, the high speed current flow is seriously restricted.

Moreover, the capacitors 193 and 195 are provided between the power line and the ground line to secure a proper performance of the device under test by filtering out the noise ΌΓ surge pulses on the power lines. The capacitors 193 have a relatively large value such as lOμF and can' be disconnected from the power lines by switches if necessary. The capacitors 195 have a relatively small capacitance value such as O.OlμF and fixedly connected close to the DUT. These capacitors serve the function as high frequency 'decoupling on the power lines. In other words, the capacitors limit the high frequency performance of the probe contactor.

Accordingly, the most widely used probe contactors as noted above are limited to the frequency bandwidth of approximately 200MHz which is insufficient to test recent semiconductor devices. In the industry, it is considered that the frequency bandwidth on the order of 1GHz or higher, will be necessary in the near future. Further, it is desired in the industry that a probe card is capable of handling a large number of semiconductor devices, especially memories, such as 32 or more, in a parallel fashion to increase test throughput.

In' the conventional technology, the probe card and probe contactors such as shown in Figure 3 are manually made, resulting in inconsistent quality. Such inconsistent quality includes fluctuations of size, frequency bandwidth, contact forces and resistance, etc. In the conventional probe contactors, another factor making the contact performance unreliable is a temperature change under which the probe contactors and the semiconductor wafer under test have different temperature expansion ratios. Thus, under the varying temperature, the contact positions therebetween vary which adversely affects the contact force, contact resistance and bandwidth. Thus, there is a need of a contact structure with a new concept which can satisfy the requirement in the next generation semiconductor test technology.

Summary of the Invention Therefore, it is an object of the present invention to provide a contact structure having a large number of contactors for electrically contacting with contact targets with a high frequency bandwidth, high pin counts and high contact performance as well as high reliability.

It is a further object of the present invention to provide a contact structure having a large number of contactors where the contactors and the contactor carrier can be assembled easily by using a lock mechanism incorporating a sliding plate.

It is a further object of the present invention to provide a contact structure formed of a contactor carrier and a plurality of contactors where the contactors are easily and securely mounted on the contactor carrier with use of a contactor adapter.

It is a further object of the present invention to provide a contact structure to establish electrical connection with a large number of semiconductor devices for testing such semiconductor devices in parallel at the same time.

It is¹ a further object of the present invention to provide a method for producing a large number of contactors in a two dimensional manner on a silicon substrate, removing the contactors from the substrate and mounting the contactors on a contact substrate in a three dimensional manner to form a contact structure.

In the present invention, a contact structure is formed of a large number of contactors produced on a planar surface of a dielectric substrate such as a silicon substrate by a photolithography technology. The contact structure of the present invention is advantageously applied to testing and burning-in¹ semiconductor devices, such as LSI and VLSI chips, semiconductor wafers and dice, packaged ICs, printed circuit boards and the like. The contact structure of the present invention can also be used as components of electronics devices such as IC leads and pins .

The first aspect of the present invention is a contact structure' for establishing electrical connection with contact targets . The contact structure is formed of a contactor carrier and a plurality of contactors . The contactor ' has an upper end oriented in a vertical direction with a cut-out to establish a lock mechanism, a lower end portion oriented in a direction opposite to the upper end which functions as a contact point for electrical connection with a contact target , and a diagonal beam portion provided between the upper end and the lower end to function as a spring. The second aspect of the present invention is a contact structure which is formed of a contactor carrier and a plurality of contactors . The contactors are mounted on the contactor carrier through a contactor adapter. The contactor has an upper end oriented in a vertical direction, a lower end which functions as a contact point for electrical connection with a contact target, a diagonal beam portion provided between the upper end and the lower end to function as a spring.

A further aspect of the present invention is a method of producing the contactors in a two dimensional manner on a silicon substrate and removing therefrom for establishing a contact structure. Various production methods are used for producing the contactor on the planar surface of the substrate. The contactors are removed from the substrate and mounted on the contactor carrier.

A further aspect of the second present invention is a probe contact assembly including the contact structure of the present invention. The probe contact assembly is formed of a contactor carrier having a plurality of contactors mounted on a surface thereof, a probe card for mounting the contactor carrier and establishing electrical communication betwee ' the contactors and electrodes provided on the probe card, and a pin block having a plurality of contact pins to interface between the probe card and a semiconductor test system when the pin block is attached to the probe card. Each contactor has a structure as described above with respect to the first aspect of the present invention. According to the present invention, the contact structure .has a large number of contactors which are easily and securely mounted on the contactor carrier with use of the shift lock mechanism or the contactor adapters . The contact structure has a very high frequency bandwidth and is able to achieve the consistent quality, high reliability and long life in the contact performance as well as low cost. Further, because the contactors are assembled on the same substrate material as that of the device under test, it is possible to compensate positional errors caused by temperature changes.

Further, according to the present invention, the production process is able to produce a large number of contactors in a horizontal direction on the silicon substrate .by using relatively simple technique. Such contactors are removed from the substrate and mounted on a contact substrate in a vertical direction then assembled using the cut on the upper end of the contacts and sliding the top 'layer of the carrier. The contact structure produced by the present invention are low cost and high efficiency and have high mechanical strength and reliability.

Brief Description of the Drawings

Figure 1 is a schematic diagram showing a structural relationship between a substrate handler and a semiconductor test system having a test head.

Figure 2 is a diagram showing an example of more detailed structure for connecting the test head of the semiconductor test system to the substrate handler through an interface component .

Figure 3 is a bottom view showing an example of the probe card having an epoxy ring for mounting a plurality of probe contactors in the conventional technology. Figures 4A-4E are circuit diagrams showing equivalent circuits of the probe card of Figure 3.

Figures 5A-5C are schematic diagrams showing examples of contact structure of the present invention using contactors produced in a horizontal direction on a substrate and vertically mounted on a contactor carrier.

Figures 6A and 6B are schematic diagrams showing a basic concept of production method of the present invention in which a large number of contactors are formed on a planar surface of a substrate and removed therefrom for later processes .'

Figures 7A-7C are diagrams showing details of the contactor of the present invention wherein Figures 7A and 7B are front views of the contactor when no pressure is applied thereto and Figure 7C is a front view of the contactor of Figure 7B when pressed against the contact target.

Figures 8A-8L are schematic diagrams showing an example of production process in the present invention for producing the contactors of the present invention. Figures 9A-9D are schematic diagrams showing another example of production process in the present invention for producing i he contactors of the present invention.

Figures 10A-10N are schematic diagrams showing an example of process for producing the contactors of the present invention on the surface of a substrate and transferring the contactors to an intermediate plate.

Figures 11A and 11B are schematic diagrams showing an example of pick and place mechanism and its process for picking the contactors and placing the same on a contactor carrier to produce the contact structure of the present invention.

Figures 12A-12C are schematic diagrams showing the process for assembling and locking the contactors on the contactor carrier in the present invention. Figure 13 is a cross sectional view showing an example of probe contact assembly using the contact structure of the present invention for use between a semiconductor device under test and a test head of a semiconductor test system.

Figure 14. is a cross sectional view showing another example of probe contact assembly using the contact structure of the present invention for use as an interface between the semiconductor device under test and a test head of the semiconductor test system.

Figure 15 is a cross sectional view showing a further example of contact structure of the present invention including' the contactors, contactor carrier and contactor adapter.

Figures 16A-16C are front views showing examples of structure ■ of the contactors of the present invention using the concept shown in Figure 15.

Figures 17A-17D are perspective views showing the contact structure of the present invention based on the concept of Figure 15 in which Figure 17A shows the contactor. Figure 17B shows the contactor adapter. Figure 17C shows the contactor .'adapter with the contactors mounted thereon, and Figure 17D shows the contactor carrier for mounting the contactor adapter of Figure 17C.

Figure 18 is a cross sectional view showing a further example. of probe contact assembly using the contact structure of Figure 15 arranged between a semiconductor device under test and a test head of a semiconductor test system.

Figure 19 is a cross sectional view showing a further example of probe contact assembly using the contact structure of Figure 15 arranged between the semiconductor device under test and a test head of the semiconductor test system.

Detailed Description of the Invention The first embodiment of the present invention will now be explained in detail with reference to Figures 5-14. It should be noted that the description of the present invention includes such terms as "horizontal" and "vertical" . The inventors use these terms to describe relative positional relationship of the components associated with the present invention. Therefore, the interpretation of the terms "horizontal" and "vertical" should not be limited to absolute meanings such as earth horizontal or gravity vertical . Figure 5A and Figure 5B show an example of contact structure in the first embodiment of the present invention. The contact structure is configured by a contactor carrier 20 and contactors 30. In an application of semiconductor test, the contact structure is positioned, for example, over a semiconductor device such as a semiconductor wafer 300 to be tested. When the silicon wafer 300 is moved upward, the lower ends of the contactors 30 contact with contact pads 320 on the semiconductor wafer 300 to establish electrical communication therebetween. The contactor carrier 20 is comprised of a system carrier 22 and a sliding plate (layer) 25. The sliding plate 25 is to lock the contactors 30 on the contactor carrier 20 by sliding (shifting) on the system carrier 22. Figure 5A shows the situation prior to locking the contactors 30 on the contactor carrier 20 and Figure 5B shows the ' situation where the contactors 30 are locked on the contactor carrier by shifting the sliding plate 25. The contactor carrier 20 is preferably made of silicon or dielectric material such as polyimide, ceramic or glass. The system carrier 22 and the sliding plate 25 both have through holes for mounting the contactors 30.

In Figures 5A and 5B, each contactor 30 is composed of an upper end (base portion) 33, a diagonal beam (spring) portion 32, and a lower end (contact portion) 35. Each contactor 30 is produced so that the upper end 33 of the contactor has a cut-out (lock groove) 39 to receive the sliding plate 25 to lock the contactors on the contactor carrier 20. Preferably, stopper 38 is provided to each contactor 30 to securely mount the contactor 30 on the contactor carrier 20. Namely, the stopper 38 limits the upward movement of the contactor 30 by engaging with the bottom surface of the system carrier 22. The stopper 38 also functions to firmly lock the contactors 30 on the contactor carrier 20 in combination with the sliding plate 25 when the sliding plate 25 fits in the cut-outs 39.

The diagonal beam portion 32 diagonally extends from the upper lend 33 to the lower end 35. The upper end 33 and the lower end 35 function as contact points to establish electrical communication with other components. In the semiconductor test application, the upper end 33 functions to contact with a probe card of the test system and the lower end 35 functions to contact with a contact target such as the contact pad 320 on the semiconductor wafer 300. For assembling the contactors 30 on the contactor carrier 20, first, the contactors 30 are inserted in the through holes produced on the sliding plate 25 and the system carrier 22. For this purpose, the sliding plate 25 is horizontally shifted on the surface of the system carrier 22 so that the through holes on the sliding plate 25 and the through holes on the system carrier match with one another on the same vertical axes. In the example of Figure 5A, the sliding plate 25 is positioned in the right hand side. In Figure 5B, after inserting all the contactors in the through holes on the system carrier and the sliding plate, the sliding plate 25 is shifted in the horizontal position toward the left to be inserted in the cut-outs 39 of the contactors 30. Accordingly, the contactors 30 are locked on the contactor carrier 20.

Figure 5C shows another example of the contact structure of the present invention. In this example, the contactor: carrier 20 is comprised of a system carrier 22, a top carrier 24, a sliding plate 25, an intermediate carrier 26, and a bottom carrier 28. The contactor carrier 20 is preferably made of silicon or dielectric material such as polyimide; ceramic or glass. The system carrier 22 supports the top, intermediate, and bottom carriers with predetermined spaces therebetween.

The top carrier 24, the intermediate carrier 26 and the bottom carrier 28 respectively have through holes for mounting the contactors 30. The sliding plate 25 is provided slidably on the top carrier 24 in the horizontal direction. In the same manner stated above with reference to Figures 5A and 5B, the sliding plate 25 also has through holes for inserting the contactors 30 therein. After inserting the contactors 30 in the through holes on the top carrier 24 and the sliding plate 25, the sliding plate 25 is shifted toward the left to lock the contactors 30 by fitting the sliding plate 25 in the cut-outs 39 of the contactors 30. This locking mechanism (shift-lock mechanism) and process will be explained in more detail later with reference to Figures 12A-12C.

In Figure 5C, each contactor 30 has a cantilever like shape as a whole which is composed of an upper end (base portion) 33, a diagonal beam (spring) portion 32, a straight beam portion 36, a lower end (contact portion) 35 and a return portion 37. Each contactor 30 are produced so that the upper end 33 of the contactor would have the cut-out 39 to receive the sliding plate 25 on the top carrier 24. Preferably, stoppers 34 and 38 are provided to each contactor 30 to securely mount the contactor 30 on the contactor _' carrier 20. The stopper 38 limits the upward movement of the contactor 30 by engaging with the top carrier 24 and the stopper 34 limits the downward movement of the contactor 30 by engaging with the intermediate carrier 26.

The diagonal beam portion 32 diagonally extends between the upper end 33 and the straight beam portion 36. The straight beam portion 36 extends downwardly between the diagonal beam portion 32 and the lower end 35. The upper end 33 and the lower end 35 function as contact points to establish'electrical communication with other components. In the semiconductor test application, the upper end 33 functions to contact with a probe card of the test system and the lower end 35 functions to contact with a contact target such as the contact pad 320 on the semiconductor wafer 300.¹

The return portion 37 runs upwardly from the lower end 35 in parallel with the straight beam portion 36. In other words, the return portion 37 and the straight beam portion 36 constitute a space (gap) S therebetween at about a position inserted in the through hole of the bottom plate carrier 28. This structure ensures a sufficient width with respect to the through holes on the bottom carrier 28 and allows flexibility when deforming the contactor 30. This is effective when the contactor is pressed against the contact target, which will be further explained later with reference to Figures 7A and 7B.

The contactors 30 are mounted on the contactor carrier 20 via the through holes provided therein. In this example, the top carrier 24, the sliding plate 25, the intermediate carrier: 26 and the bottom carrier 28 respectively include the through holes to receive the contactors 30 therein. The upper end 33 is projected from the upper surface of the top carrier 24 and the lower end 35 is projected from the lower surface of the bottom carrier 28. The sliding plate 25 can slide on the top carrier 24 so that it engages with the cutout 39 on i the upper end of the contactor 30, thereby locking the contactors 30 on the contactor carrier 20.

The middle portion of the contactor 30 may be loosely coupled to the intermediate carrier 26. Thus, the contactor 30 is movable in the intermediate portion and the lower portion while the upper end portion is locked on the top carrier 24. When the contact structure is pressed against a contact target, such as the contact pad 320 on the semiconductor wafer 300, the contactor 30 deforms to effectuate the spring action noted below.

The diagonal beam (spring) portion 32 of the contactor 30 functions as a spring to produce a resilient force when the lower end 35 is pressed against the contact target. The lower end (contact point) 35 of the contactor 30 is preferably sharpened to be able to scrub the surface of the contact pad 320. The resilient force promotes such a scrubbing effect at the lower end 35 against the surface of contact pad 320. The scrubbing effect improves the contact performance when the contact point scrubs the metal oxide surface layer of the contact pad 320 to electrically contact the conductive material of the contact pad 320 under the metal oxide surface layer.

Figures 6A-6B show the basic concept of the present invention for producing such contactors. In the present invention, as shown in Figure 6A, the contactors 30 are produced on a planar surface of a substrate 40 in a horizontal direction, i.e., in parallel with the planar surface of the substrate 40. In other words, the contactors 30 are built in a two dimensional manner on the substrate 40. Then, the contactors 30 are removed from the substrate 40 to be mounted on the contactor carrier 20 shown in Figures 5A- 5C in a vertical direction, i.e., in a three dimensional manner. Typically, the substrate 40 is a silicon substrate although other substrate such using dielectric materials are also feasible.

In the example of Figures 6A and 6B, as noted above, the contactors 30 are produced on the planar surface of the substrate 40 in the horizontal direction. Then, in the example of Figure 6B, the contactors 30 are transferred from the substrate 40 to an adhesive member 90, such as an adhesive tape, adhesive film or adhesive plate (collectively "adhesive tape"). In the further process, the contactors 30 on the adhesive tape 90 are removed therefrom to be mounted on the contactor carrier 20 of Figures 5A-5C in a vertical direction, i.e., in a three dimensional manner with use, for example, of a pick and place mechanism.

Figure 7A shows more details of the contactor 30 of the present invention used in the contact structure of Figures 5 and 5B. Figures 7B and 7C show more details of the contactor' 30 of the present invention used in the contact structure . of Figure 5C. Figure 7B is a front view of the contactor 30 when no pressure is applied thereto, and Figure 7C is a front view of the contactor 30 when the pressure is applied to the contact structure by being pressed against the contact target.

As noted above with reference to Figures 5A and 5B, the contactor i 30 of Figures 7A has the upper end (base portion) 33 with the cut-out 39, the diagonal beam (spring) portion 32, and the lower end (contact portion) 35. In the example of Figures 7B and 7C, the contactor 30 has the upper end (base portion) 33 with the cut-out 39, the diagonal beam (spring) portion 32, the straight beam portion 36, the lower end (contact portion) 35 and the return portion 37. On each contactor 30, the cut-out 39 is provided to the upper end 33 so that it can receive the sliding plate 25 on the contactor carrier 2.0 to lock the contactor in place.

In the semiconductor test application, the upper end 33 contacts with a probe card of the test system such as shown in Figure 13 and the lower end 35 contacts with the contact target such as a semiconductor wafer under test. When mounted on the contactor carrier 20 of Figure 5C, the upper end 33 is projected from the upper surface of top carrier 24 of the contactor carrier 20 and the lower end 35 is projected from the lower surface of bottom carrier 28 of the contactor carrier 20.

In the front view of Figure 7B, the diagonal beam portion 32 and the straight beam portion 36 preferably have a width. which is smaller than that of the upper end 33 or the lower end 35 to promote the spring actions. The space (gap) S between the return portion 37 and the straight beam portion 36 further promotes the spring actions as shown in Figure 7C. Namely, the space S allows the horizontal movements of the straight beam portion 36 and the diagonal beam portion 32 in the manner shown in Figure 7C. Because of the reduced width and of the beams portions 32 and 36 and the space S formed at the lower end 35, the diagonal beam portion 32 and the straight beam portion 36 easily deform when the contactor 30 is pressed against the contact target. Figures 8A-8L are schematic diagrams showing an example of production process for producing the contactor 30 of the present invention. In Figure 8A, a sacrificial layer 42 is formed on a substrate 40 which is typically a silicon substrate. Other substrate is also feasible such as a glass substrate ; and a ceramic substrate. The sacrificial layer 42 is made, for example, of silicon dioxide (Si0₂) through a deposition process such as a chemical vapor deposition (CVD) . The sacrificial layer 42 is to separate contactors 30 from the silicon substrate in the later stage of the production process .

An adhesion promoter layer 44 is formed on the sacrificial layer 42 as shown in Figure 8B through, for example, an evaporation process. An example of material for the adhesion promoter layer 44 includes chromium (Cr) and titanium (Ti) with a thickness of about 200-1,000 angstrom, for example. The adhesion promoter layer 44 is to facilitate the adhesion of conductive layer 46 of Figure 8C on the silicon substrate 40. The conductive layer 46 is made, for example, of copper (Cu) or nickel (Ni) , with a thickness of about 1,000-5,000 angstrom, for example. The conductive layer 46 is to establish electrical conductivity for an electroplating process in the later stage.

In the next process, a photoresist layer 48 is formed on the conductive layer 46 over which a photo mask 50 is precisely aligned to be exposed with ultraviolet (UV) light as shown in Figure 8D. The photo mask 50 shows a two dimensional image of the contactor 30 which will be developed on the photoresist layer 48. As is well known in the art, positive as well as negative photoresist can be used for this purpose. If a positive acting resist is used, the photoresist covered by the opaque portions of the mask 50 hardens (cure) after the exposure. Examples of photoresist material include Novolak (M-Cresol-formaldehyde) , PMMA (Poly Methyl Methacrylate), SU-8 and photo sensitive polyimide. In the development process, the exposed part of the resist can be dissolved and washed away, leaving a photoresist layer 48 of Figure 8E having an opening or pattern "A". Thus, the top view of Figure 8F shows the pattern or opening "A" on the photoresist layer 48 having the image (shape) of the contactor 30.

In the photolithography process in the foregoing, instead of the UN light, it is also possible to expose the photoresist layer 48 with an electron beam or X-rays as is known in the art. Further, it is also possible to directly write the image of the contact structure on the photoresist layer 48 by exposing the photoresist 48 with a direct write electron beam. X-ray or light source (laser).

The conductive material such as copper (Cu), nickel (Νi), aluminum (Al), rhodium (Rh), palladium (Pd) , tungsten (W) or other metal, nickel-cobalt (ΝiCo) or other alloy combinations thereof is deposited (electroplated) in the pattern "A" of the photoresist layer 48 to form the contactor 30 as shown in Figure 8G. Preferably, a contact material which is different from that of the conductive layer 46 should be used to differentiate etching characteristics from one another as will be described later. The over plated portion of the contactor 30 in Figure 8G is removed in the grinding (planarizing) process of Figure 8H. The above noted process may be repeated for producing contactors having different thickness by forming two or more conductive layers . For example, a certain portion of the contactor 30 may be designed to have a thickness larger than that of the other portions. In such a case, after forming a first layer of the contactors (conductive material), if necessary, the processes of Figures 8D-8H will be repeated to form a second layer or further layers on the first layer of the contactors .

In the next process, the photoresist layer 48 is removed in a resist stripping process as shown in Figure 81. Typically, the photoresist layer 48 is removed by wet chemical processing. Other examples of stripping are acetone-based stripping and plasma 0₂ stripping. In Figure 8J, the sacrificial layer 42 is etched away so that the contactor 30 is separated from the silicon substrate 40. Another etching process is conducted so that the adhesion promoter layer 44 and the conductive layer 46 are removed from the contactor 30 as shown in Figure 8K.

The etching condition can be selected to etch the layers 44 and 46 but not to etch the contactor 30. In other words, to etch the conductive layer 46 without etching the contactor 30, as noted above, the conductive material used for the contactor 30 must be different from the material of the conductive layer 46. Finally, the contactor 30 is separated from any other materials as shown in the perspective view of Figure 8L. Although the production process iii Figures 8A-8L shows only one contactor 30, in an actual production process, as shown in Figures 6A and 6B, a large number of contactors are produced at the same time.

Figures 9A-9D are schematic diagrams showing an example of production process for producing the contactors of the present invention. In this example, an adhesive tape 90 is incorporated in the production process to transfer the contactors 30 from the silicon substrate 40 to the adhesive tape. Figures 9A-9D only show the latter part of the production process in which the adhesive tape 90 is involved. Figure 9A shows a process which is equivalent to the process shown in Figure 81 where the photoresist layer 48 is removed in the resist stripping process. Then, also in the process of Figure 9A, an adhesive tape 90 is placed on an upper surface of the contactor 30 so that the contactor 30 adheres to the adhesive tape 90. As noted above with reference to Figure 6B, within the context of the present invention, the adhesive tape 90 includes other types of adhesive member, such as an adhesive film and adhesive plate, and the like. The adhesive tape 90 also includes any member which attracts the contactor 30 such as a magnetic plate or tape, an electrically charged plate or tape, and the like.

In the process shown in Figure 9B, the sacrificial layer 42 is etched away so that the contactor 30 on the adhesive tape 90 is separated from the silicon substrate 40. Another etching process is conducted so that the adhesion promoter layer 44 and the conductive layer 46 are removed from the contactor 30 as shown in Figure 9C.

As noted above, in order to etch the conductive layer 46 without etching the contactor 30, the conductive material used for the contactor 30 must be different from the material of the conductive layer. Although the production process iii Figures 9A-9C shows only one contactor, in an actual production process, a large number of contactors are produced at the same time. Thus, a large number of contactors 30 are transferred to the adhesive tape 90 and separated ' from the silicon substrate and other materials as shown in the top view of Figure 9D.

Figures 10A-10N are schematic diagrams showing a further example of production process for producing the contactor; 30 where the contactors are transferred to the adhesive tape. In Figure 10A, an electroplate seed (conductive) layer 342 is formed on a substrate 340 which is typically a silicon or glass substrate. The seed layer 342 is made, for example, of copper (Cu) or nickel (Ni) , with a thickness of about 1,000-5,000 angstrom, for example. A chrome-inconel layer 344 is formed on the seed layer 342 as shown in Figure 10B through, for example, a sputtering process . In the next process in Figure 10C, a conductive substrate 346 is formed on the chrome-inconel layer 344. The conductive substrate 346 is made, for example, of nickel-cobalt (NiCo) with a thickness of about 100-130μm. After passivating the conductive substrate 346, a photoresist layer 348 with a thickness of about 100-120μm is formed on the conductive substrate 346 in Figure 10D and a photo mask 350 is precisely aligned so that the photoresist layer 348 is exposed with ultraviolet (UN) light as shown in Figure 10E. The photo mask 350 shows a two dimensional image of the contactor 30 which will be developed on the surface of the photoresist layer 348.

In the development process, the exposed part of the resist can be dissolved and washed away, leaving a photoresist layer 348 of Figure 10F having a plating pattern transferred from the photo mask 350 having the image (shape) of the contactor 30. In the step of Figure 10G, contactor material is electroplated in the plating pattern on the photoresist layer 348 with a thickness of about 50-60μm. An example of the conductive material is nickel-cobalt (ΝiCo) . The nickel-cobalt contactor material will not strongly adhere to the conductive substrate 346 made of nickel-cobalt.

In the case where the contactor has two or more different thickness, the above noted process may be repeated for producing the contactor by forming two or more conductive layers. Namely, after forming a first layer of the contactors, if necessary, the processes of Figures 10D- 10G are repeated to form a second layer or further layers on the first layer of the contactors .

In the next process, the photoresist layer 348 is removed in' a resist stripping process as shown in Figure 10H. In Figure 101, the conductive substrate 346 is peeled from the chrome-inconel layer 344 on the substrate 340. The conductive substrate 346 is a thin substrate on which the contactors 30 are mounted with a relatively weak adhesive strength. The top view of the conductive substrate 346 having the contactors 30 is shown in Figure 10J.

Figure 10K shows a process in which an adhesive tape 90 is placed on an upper surface of the contactors 30. The adhesive strength between the adhesive tape 90 and the contactors 30 is greater than that between the contactors 30 and the <■. conductive substrate 346. Thus, when the adhesive tape 90 is removed from the conductive substrate 346, the contactors 30 are transferred from the conductive substrate 346 to the adhesive tape 90 as shown in Figure 10L. Figure 10M shows a top view of the adhesive tape 90 having the contactors 30 thereon and Figure ION is a cross sectional view of the adhesive tape 90 having the contactors 30 thereon.

Figures 11A and 11B are schematic diagrams showing an example of process for picking the contactors 30 from the adhesive tape 90 and placing the contactors on the contactor carrier 20. The pick and place mechanism of Figures 11A and 11B is advantageously applied to the contactors produced by the production process of the present invention described with reference to Figures 9A-9D and Figures 10A-10N involving ' the adhesive tape. Figure 11A is a front view of the pick and place mechanism 80 showing the first half process of the pick and place operation. Figure 11B is a front view of the pick and place mechanism 80 showing the second half process of the pick and place operation.

In this example, the pick and place mechanism 80 is comprised of a transfer mechanism 84 to pick and place the contactors 30, mobile arms 86 and 87 to allow movements of the transfer mechanism 84 in X, Y and Z directions, tables 81 and 82 whose positions are adjustable in X, Y and Z directions, and a monitor camera 78 having, for example, a CCD image sensor therein. The transfer mechanism 84 includes a suction arm 85 that performs suction (pick operation) and suction release (place operation) operations for the contactors 30. The suction force is created, for example, by a negative pressure such as vacuum. The suction arm 85 rotates in a predetermined angle such as 90 degrees.

In operation, the adhesive tape 90 having the contactors 30 and the contactor carrier 20 having the bonding¹ locations 32 (or through holes) are positioned on the respective tables 81 and 82 on the pick and place mechanism 80. As shown in Figure 11A, the transfer mechanism 80 picks the contactor 30 from the adhesive tape 90 by suction force of the suction arm 85. After picking the contactor 30, the suction arm 85 rotates by 90 degrees. for example, as shown in Figure 11B. Thus, the orientation of the contactor 30 is changed from the horizontal direction to the vertical direction. This orientation change mechanism is just an example, and a person skilled in the art knows that there are many other ways to change the orientation of the contactors. The transfer mechanism 80 then places the contactor 30 on the contactor carrier 20. The contactor 30 is attached to the contactor carrier 20 using the sliding plate on the carrier to lock the contactor and the carrier after the contactors are inserted in the through holes.

Figures 12A-12C are schematic diagrams showing the process to securely assemble and lock the contactors 30 on the contactor carrier 20 with the use of the sliding plate (layer): 25. The sliding plate 25 fits with the cut-outs 39 formed on the upper portion of the contactors 30. As shown in Figure 12A, the contactor carrier 20 is provided with the sliding plate 25 on the system carrier 22. Through holes 29 of the sliding plate 25 and through holes 23 of the system carrier 22 match with one another on the same vertical axes. A spacer 27 may be inserted in the gap between the sliding plate 25 and the system carrier 22 to maintain the position of the sliding plate 25.

Then, the contactors 30 are placed through the through holes 23 and 29 on the system carrier 22 and the sliding plate 25 as shown in Figure 12B. The cut-outs 39 of the contactors 30 are positioned on the same vertical position as the sliding plate 25 on the contactor carrier 20. The stopper 38 formed at the middle portion of the contactor 30 prohibits the upper movement of the contactor when engaging with the bottom surface of the system carrier 22.

After all of the contactors 30 are inserted in the through holes, the spacer 27 is removed from the contactor carrier 20, therefore allowing the sliding plate 25 to spring back toward the left. Thus, the sliding plate 25 fits in the cut-outs 39 on the upper portions of the contactors 30 as shown in Figure 12C. By inserting the sliding plate 25 into the cut-outs 39, the contactors 30 and the contactor carrier 20 are easily and securely assembled. Furthermore, if the contactor carrier 20 is not provided with the mechanism to spring back the sliding plate 25 noted above, the sliding plate 25 may be manually shifted to the left and is maintained in the left position by using the spacer 27 in the side opposite to that of Figure 12B. Figure 13 is a cross sectional view showing an example of total stack-up structure for forming a probe contact assembly using the contact structure of the present invention. The probe contact assembly is used as an interface between the device under test (DUT) and the test head of the semiconductor test system such as shown in Figure 2. In this example, the probe contact assembly includes a routing board (probe card) 260, and a pogo-pin block (frog ring) 130 provided over the contact structure in the order shown in Figure 13. The contact structure is configured by a plurality of contactors 30 mounted on the contactor carrier 20. The upper end (base portion) 33 of each of the contactors 30 is projected at the upper surface of the contactor carrier 20. The lower end (contact portion) 35 is projected from the lower surface of the contactor carrier 20. In the present invention, the diagonal beam (spring) portion 32 between the upper end 33 and the intermediate portion has a cantilever shape which is inclined upwardly from the intermediate plate carrier 26. The contactors 30 may be slightly loosely inserted in the through holes on the contactor carrier 20 in a manner allowing small movements in the vertical and horizontal directions when pressed against the semiconductor wafer 300 and the probe card 260.

The probe card 260, pogo-pin block 130 and contact structure are mechanically as well as electronically connected with one another, thereby forming a probe contact assembly. Thus, electrical paths are created from the contact point of the contactors 30 to the test head 100 through the cables 124 and performance board 120 (Figure 2). Thus, when the semiconductor wafer 300 and the probe contact assembly are pressed with each other, electrical communication will be established between the DUT (contact pads 320 on the wafer 300) and the test system.

The pogo-pin block (frog ring) 130 is equivalent to the one shown in Figure 2 having a large number of pogo-pins to interface between the probe card 260 and the performance board 120. At upper ends of the pogo-pins, cables 124 such as coaxial cables are connected to transmit signals to printed circuit boards (pin electronics cards) 150 in the test head 100 in Figure 2 through the performance board 120. The probe card 260 has a large number of electrodes 262 and 265 on the upper and lower surfaces thereof.

When assembled, the base portions (upper ends) 33 of the contactors 30 contact the electrodes 262. The electrodes 262 and 265 are connected through interconnect traces 263 to fan-out the pitch of the contact structure to meet the pitch of the pogo-pins in the pogo-pin block 130. Because' the contactors 30 are loosely inserted in the through holes of the contactor carrier 20, the diagonal beam portions 32 of the contactors 30 deform easily and produce resilient contact forces toward the electrodes 262 and the contact pads 320 when pressed against the semiconductor wafer 300.

Figure 14 is a cross sectional view showing another example of probe contact assembly using the contact structure of the present invention. In this example, the probe contact assembly includes a conductive elastomer 250, a probe card 260, and a pogo-pin block (frog ring) 130 provided over the contact structure. Since the contactor 30 has the diagonal beam (spring) portion as mentioned above to produce elasticity in the vertical direction, such a conductive elastomer is usually unnecessary. However, the conductive elastomer is still useful for compensating the unevenness of the gaps (planarity) between the probe card 260 and the contact structure.

The conductive elastomer 250 is provided between the contact structure and the probe card 260. When assembled, the upper ends 33 of the contactors 30 contact the conductive elastomer 250. The conductive elastomer 250 is an elastic sheet having a large number of conductive wires 252 in a vertical direction. For example, the conductive elastomer 250 is comprised of a silicon rubber sheet and a multiple rows of metal filaments 252. The metal filaments (wires) 2'52 are provided in the vertical direction of Figure 14, i.e. , orthogonal to the horizontal sheet of the conductive elastomer 250. An example of pitch between the metal filaments is 0.05mm or less and thickness of the silicon rubber sheet is about 0.2mm. Such a conductive elastomer is produced by Shin-Etsu Polymer Co. Ltd, Japan, and available in the market.

The second embodiment of the present invention will now be explained in detail with reference to Figures 15-19. Figure 15 is a cross sectional view showing an example of contact structure in the second embodiment of the present invention. The contact structure is configured by a contactor carrier 420, a contactor adapter 425, and a plurality^of contactors 430. In the application of semiconductor testing, when the silicon wafer 300 is moved upward, the lower ends of the contactors 430 contact with contact pads 320 on the semiconductor wafer 300 to establish electrical communication therebetween.

The contactor carrier 420 and the contactor adapter 425 are made, for example, of silicon or dielectric material such as polyimide, ceramic and glass. The contactors 430 are made of conductive material or coated with conductive material. Two or more contactors 430 are attached to the contactor adapter 425 and the contactor adapter is attached to the contactor carrier 420. Two or more contactor adapters 25 each carrying a plurality of contactors 430 are attached to the contactor carrier, more details of which will be: described later with reference to Figures 17A-17D.

In Figure 15, each contactor 430 is composed of an upper end (base portion) 433, a diagonal (spring) portion 432, and a lower end (contact portion) 435. A stopper 438 is provided to each contactor 430 with a predetermined distance from the upper end 433 to securely mount the contactor 430 on the contactor adapter 425. Namely, the upper end 433 and the stopper 438 form a cut-out 439 (Figures 16A-16C) to be fit in a groove 427 on the contactor adapter 425. In other words, the distance between the upper end 433 and the stopper 438 is formed to be about the same as the thickness of the contactor adapter 425. The cut-outs 439, the contactor adapter 425 and the contactor carrier 420 create a lock mechanism for securely and easily mounting the contactors 430 on the contactor carrier 420.

The diagonal portion 432 diagonally extends from the upper end 433 to the lower end 435. The upper end 433 and the lower end 435 function as contact points to establish electrical communication with other components. In the semiconductor test application, the upper end 433 functions to contact with a probe card of the test system and the lower end 435 functions to contact with a contact target such as the contact pad 320 on the semiconductor wafer 300. As noted above, the contactors 430 are mounted on the contactor carrier 420 via the contactor adapter 425. The upper end 433 and the lower end 435 are respectively projected from the upper surface and the lower surface of the contactor adapter 425. The diagonal (spring) portion 432 of the contactor 430 functions as a spring to produce a resilient force when the lower end 435 is pressed against the contact target such as the contact pad 320. The lower end (contact point) 435 of the contactor 430 is preferably sharpened to be able to scrub the surface of the contact pad 320. The resilient force promotes such a scrubbing effect at the lower end 435 against the surface of contact pad 320. The scrubbing effect promotes the contact performance when the contact point 435 scrubs the metal oxide surface layer of the contact pad 320 to electrically contact the conductive material of the contact pad 320 under the metal oxide surface layer.

Figures 16A-16C show examples of shape of the contactor 430 of the present invention. As noted above with reference to Figure 15, the contactor 430 has the upper end (base portion) 433, the diagonal (spring) portion 432, and the lower end (contact portion) 435. Cut-outs (indentations) 439 are formed by the upper end 433 and the stopper 438 so that the .contactor 430 can snugly fit in the groove formed on the contactor adapter 425.

In the example of Figure 16A, the diagonal portion 432 is a straight beam running in a diagonal direction to promote' the spring action. In the example of Figure 16B, the diagonal portion 432 is bent in a zig-zag fashion at the intermediate position to promote the spring action. In the example of Figure 16C, the cut-out 439 is formed only one side of the upper portion of the contactor 430. Many other shapes of the contactor can be used in the contact structure of the present invention so long as it has a structure to be properly attached to the contactor adapter 425.

Preferably, the diagonal portion 432 has a width and/or thickness : smaller than that of the upper end 433 to promote the spring action. Because of the reduced width and of the diagonal portion 432, it can easily deform when the contactor 430 is pressed against the contact target. As noted above with reference to Figures 6 and 8-10, the contactors 430 are produced on the horizontal surface of the silicon substrate in the horizontal direction. To achieve such difference in the thickness of the contactor 430, the process for depositing the conductive material will be repeated in the production process described above with reference. to Figures 8-10.

Figure 17A-17D are schematic diagrams showing the process to securely mount the contactors 430 on the contactor carrier 420 using the contactor adapter 425. As shown in Figure 17A, the contactor 430 is provided with the cut-outs (indentations) 439 at both sides of the upper portion thereof. The cut-out 439 has a predetermined length (distance between the upper end 433 and the stopper 438) to be securely attached to the contactor adapter 425.

The contactor adapter 425 is provided with grooves 427 and a stopper 426 as shown in Figure 17B. The cut-outs 439 of the contactor 430 and the grooves 427 of the contactor adapter 425 are produced so that they will snugly fit to one another. Namely, the width and thickness of the cut-outs 439 of the contactor 430 are made identical to the width and thickness of the groove 427 on the contactor adapter 425. Further, the distance between the upper end 433 and the stopper 438 of the contactor is made identical to the thickness of the contactor adapter 425. The contactor adapter 425 has a stopper (step) 426 to fit with the contactor carrier 420.

In Figure 17C, the contactors 430 are mounted on the contactor adapter 425 by fitting the cut-outs 439 in the grooves 427. When mounted, the contactor adapter 425 and the contactors 430 are flush with one another at the front surfaces in Figure 17C. Adhesives (not shown) may be applied' to the contactors 430 and the contactor adapter 425 to be securely fixed with each other.

In Figure 17D, the contactor adapter 425 having the plurality of contactors 430 is inserted into the contactor carrier^: 420. In the example of Figure 17D, the contactor carrier^' 420 has a plurality of slots 424 to receive the contactor adapters 425 mounted with the contactors 430. Each slot has a step (stopper) 428 to engage with the stopper 426 of the contactor adapter 425. By inserting the contactor adapter 425 having the contactors 430 into the slot 424 of the contactor carrier 420, the contactors 430 and the contactor carrier 420 are securely and easily assembled with one another. The stopper 426 of the contactor adapter 425 contacts with the step 428 formed in the slot 424, thereby determining the vertical position of the contactors 430.

Figure 18 is a cross sectional view showing an example of total stack-up structure for forming a probe contact assembly using the contact structure in the second embodiment of the present invention. The probe contact assembly is used as an interface between the device under test (DUT) and the test head of the semiconductor test system such as shown in Figure 2. In this example, the probe contact assembly includes a routing board (probe card) 260, and a pogo-pin block (frog ring) 130 provided over the contact structure in the order shown in Figure 18.

The contact structure is configured by a plurality of contactors 430 mounted on the contactor carrier 420. The upper end (base portion) 433 of each of the contactors 430 is projected at the upper surface of the contactor carrier 420. The lower end (contact portion) 435 is projected from the lower surface of the contactor carrier 420. The contactors 430 are inserted in the slots 424 on the contactor carrier 420 via the contactor adapter 425. As noted above, the diagonal (spring) portion 432 extends in a diagonal direction between the upper end 433 and the lower end 435. The diagonal portion 432 produces a resilient force when pressed against the semiconductor wafer 300. The probe card 260, pogo-pin block 130 and contact structure are mechanically as well as electronically connected with one another, thereby forming a probe contact assembly.¹ Thus, electrical paths are created from the contact point of the contactors 430 to the test head 100 through the cables 124 and performance board 120 (Figure 2). Thus, when the semiconductor wafer 300 and the probe contact assembly are pressed with each other, electrical communication will be established between the DUT (contact pads 320 on the wafer 300) and the test system.

The pogo-pin block (frog ring) 130, the probe card 260, and the cables 124 are the same as that shown in Figures 13 and 14 and transmit signals to the printed circuit boards (pin electronics cards) 150 in the test head 100 in Figure 2 through the performance board 120. When assembled, the upper ends 433 of the contactors 430 contact the electrodes 262 of the probe card. Because the contactors 430 mounted on the contactor carrier 420 have the diagonal portions 432, the contactors 430 deform easily and produce resilient contact forces toward the contact pads 320 when pressed against the semiconductor wafer 300. Figure 19 is a cross sectional view showing another example of probe contact assembly using the contact structure in the second embodiment of the present invention. In this example, the probe contact assembly includes a conductive elastomer 250 in addition to the probe contact assembly of Figure 18. The conductive elastomer 250 is provided between the contact structure and the probe card 260. When assembled, the upper ends 433 of the contactors 430 contact the conductive elastomer 250. As noted above with reference to Figure 14, the conductive elastomer 250 is an elastic sheet such as silicon rubber having a large number of ' conductive wires 252 in a vertical direction.

According to the present invention, the contact structure has a very high frequency bandwidth to meet the test requirements of next generation semiconductor technology. In the first embodiment, the contact structure is formed' easily and securely by the shift locking mechanism wherein. the contactors are locked on the contactor carrier by the sliding plate. In the second embodiment, the contact structure is formed easily and securely by mounting the contactors on the contactor carrier through the contactor adapter. Since the large number of contactors are produced at the same time on the substrate without involving manual handling, it is possible to achieve consistent quality, high reliability and long life in the contact performance. Although only a preferred embodiment is specifically illustrated and described herein, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teachings and within the purview of the appended claims without departing the spirit and intended scope of the invention.

Claims

1. A contact structure for establishing electrical connection with contact targets, comprising: ' a plurality of contactors made of conductive material where each of the contactors is comprised of an upper end oriented in a vertical direction and has a cut-out, a lower end oriented in a direction opposite to the upper end and functions as a contact point for electrical connection with a contact target, and a diagonal beam portion provided between the upper end and the lower end to function as a spring; and a contactor carrier having a sliding plate on a upper surface thereof for mounting said plurality of contactors when said sliding plate fits in the cut-outs of¹ the contactors after inserting the contactors in through holes formed on the contactor carrier; wherein said upper end of each contactor is projected from said upper surface of said contactor carrier and said lower end of each contactor is projected from said lower surface of said contactor carrier.

2. A contact structure for establishing electrical connection with contact targets as defined in Claim 1, wherein the contactor carrier further includes a top carrier having said upper surface thereon, a bottom carrier having said lower surface thereon, and an intermediate carrier provided between the top carrier and the bottom carrier.

3. ^■ ' A contact structure for establishing electrical connection with contact targets as defined in Claim 2, wherein the contactor carrier includes a system carrier for supporting the top carrier, the intermediate carrier and the bottom carrier.

4. A contact structure for establishing electrical connection with contact targets as defined in Claim 1, wherein said contactor carrier and said sliding plate are provided with through holes for mounting the contactors therethrough.

5. A contact structure for establishing electrical connection with contact targets as defined in Claim 2, wherein said contactor is provided with a first stopper for limiting an upward displacement of the contactor by engaging with the top carrier and a second stopper for limiting a downward displacement of the contactor by engaging with the intermediate carrier.

6.i A contact structure for establishing electrical connection with contact targets as defined in Claim 1, further comprising a straight beam portion at the lower end, a return portion returned from a bottom end of the straight beam portion and running in parallel with the straight beam portion to create a predetermined gap therebetween.

7. A contact structure for establishing electrical connection with contact targets, comprising: a plurality of contactors made of conductive material where each of the contactors is comprised of an upper end oriented in a vertical direction and has a cut-out, a lower end oriented in a direction opposite to the upper end and functions as a contact point for electrical connection with a contact target, and a diagonal portion provided between the upper end and the lower end to function as a spring; a contactor adapter having a plurality of grooves running in a vertical direction for attaching the contactors by fitting in the cut-out of the contactor in the corresponding groove thereof; and a contactor carrier having a slot for mounting the plurality of contactors when the contactor adapter having the contactors is inserted therein; wherein said upper end of each contactor is projected from said upper surface of said contactor carrier and said lower end of each contactor is projected from said lower surface of said contactor carrier.

8. A contact structure for establishing electrical connection with contact targets as defined in Claim 7, wherein the contactor further includes a stopper which contacts a bottom surface of the contactor adapter when fit in the groove of the contactor adapter, and wherein the cutout is formed between the upper end and the stopper of the contactor.

9. A contact structure for establishing electrical connection with contact targets as defined in Claim 7, wherein the cut-out is formed at both sides of the contactor and width between the cut-outs of the contactor is substantially the same as width of the groove of the contactor adapter.

10. A contact structure for establishing electrical connection with contact targets as defined in Claim 7, wherein the cut-out is formed at one side of the contactor and width of the contactor at the cut-out is substantially the same as width of the groove of the contactor adapter.

11. A contact structure for establishing electrical connection with contact targets as defined in Claim 7, wherein¹ the contactor adapter further includes a stopper which engage with a step formed in the slot of the contactor carrier to determined a vertical position of the contactors when the contactor adapter is inserted in the slot .

12. A method for producing a contact structure, comprising the following steps of:

(a) forming a sacrificial layer on a surface of a substrate;

(b) forming a photoresist layer on the sacrificial layer; (σ) developing patterns of the image of the contactors on a surface of the photoresist layer;

(d) forming the contactors made of conductive material in the patterns on the photoresist layer by depositing the conductive material, each of the contactors having an upper end with a cut-out for fitting with a sliding plate or a contactor adapter to be mounted on a contactor carrier, a lower end oriented in a direction opposite to the upper end to function as a contact point, and a diagonal beam portion provided between the upper end and the lower end to function as a spring;

(e) stripping the photoresist layer off;

(f) removing the sacrificial layer so that the contactors are separated from the substrate; and (g) mounting the contactors on the contactor carrier by engaging the sliding plate with the cut-outs of the contactors or by mounting the contactor adapter having the contactors on the contactor carrier.

13. ' A method for producing a contact structure as defined in Claim 12, after forming the contactors by depositing the conductive material, the method further comprising a step of placing an adhesive tape on the contactors so that upper surfaces of the contactors are attached to the adhesive tape.

14. A method for producing a contact structure as defined in Claim 13, said step of mounting the contactors on the contactor carrier including a step of picking the contactor from the adhesive tape and changing orientation of the contactor and placing the contactor on the contactor carrier with use of a pick and place mechanism which utilizes a suction force to attract the contactor.

15. A method for producing a contact structure. comprising the following steps of:

¹ (a) forming an conductive substrate made of electric conductive material on a base substrate;

(b) forming a photoresist layer on the conductive substrate;

(c) aligning a photo mask over the photoresist layer and exposing the photoresist layer through the photo mask where the photo mask includes an image of the contactors; (d) developing patterns of the image of the contactors on a surface of the photoresist layer;

(e) forming the contactors made of conductive material in the patterns on the photoresist layer by depositing the conductive material, each of the contactors having an upper end with a cut-out for fitting with a sliding plate or a contactor adapter to be mounted on a contactor carrier, a lower end oriented in a direction opposite to the upper end to function as a contact point, and a diagonal beam portion provided between the upper end and the lower end to function as a spring;

(f) stripping off the photoresist layer;

(g) peeling the conductive substrate having contactors thereon from the base substrate; (h) placing an adhesive tape on the contactors on the conductive substrate so that upper surfaces of the contactors adhere to the adhesive tape wherein adhesive strength between the contactors and the adhesive tape is larger than that between the contactors and the conductive substrate; (i) peeling the conductive substrate so that the contactors on the adhesive tape are separated from the conductive substrate; and

( j ) mounting the contactors on the contactor carrier by engaging the sliding plate with the cut-outs of the contactors or by mounting the contactor adapter having the contactors on the contactor carrier.

16. A probe contact assembly for establishing electrical connection with contact targets, comprising: a contactor carrier having a plurality of contactors mounted on a surface thereof and a sliding plate for locking the contactors on the contactor carrier; a probe card for mounting the contactor carrier and establishing electrical communication between the contactors and electrodes provided on the probe card; and a pin block having a plurality of contact pins to interface between the probe card and a semiconductor test system when the pin block is attached to the probe card; wherein each of the contactors is comprised of an upper end oriented in a vertical direction and has a cut-out for fitting with the sliding plate thereby being mounted on the contactor carrier, a lower end oriented in a direction opposite to the upper end and functions as a contact point for electrical connection with a contact target, and a diagonal beam portion provided between the upper end and the lower end to function as a spring.

17. ' A probe contact assembly for establishing electrical connection with contact targets as defined in Claim 16, wherein the contactor carrier has an upper surface and a lower surface for mounting said plurality of contactors , and wherein said upper end of each contactor is projected from said upper surface of said contactor carrier and said lower end of each contactor is projected from said lower surface of said contactor carrier.

18. ' A probe contact assembly for establishing electrical connection with contact targets as defined in Claim 16, wherein the contactor carrier includes a top carrier having said upper surface thereon, a bottom carrier having said lower surface thereon, and an intermediate carrier provided between the top carrier and the bottom carrier.

19. A probe contact assembly for establishing electrical connection with contact targets as defined in Claim 18, wherein each of the top carrier, the intermediate carrier and the bottom carrier is provided with through holes for mounting the contactors therethrough.

20. A probe contact assembly for establishing electrical connection with contact targets, comprising: a contactor carrier having a contactor adapter inserted in a slot where the contactor has a plurality of contactors in a manner that cut-outs of the contactors are fitted in grooves on the contactor adapter; a probe card for mounting the contactor carrier and establishing electrical communication between the contactors and electrodes provided on the probe card; and a pin block having a plurality of contact pins to interface between the probe card and a semiconductor test system when the pin block is attached to the probe card; wherein each of the contactors is comprised of an upper end oriented in a vertical direction and has the cut-out for being fitted in the groove on the contactor adapter, a lower end oriented in a direction opposite to the upper end and functions as a contact point for electrical connection with a contact target, and a diagonal portion provided between the upper end and the lower end to function as a spring.

21. A probe contact assembly for establishing electrical connection with contact targets as defined in Claim 20,ι wherein the contactor further includes a stopper which contacts a bottom surface of the contactor adapter when fit in the groove of the contactor adapter, and wherein the cut-out is formed between the upper end and the stopper of the contactor.

22. .A probe contact assembly for establishing electrical connection with contact targets as defined in Claim 20, wherein the cut-out is formed at both sides of the contactor and width between the cut-outs of the contactor is substantially the same as width of the groove of the contactor adapter.

23. _' A probe contact assembly for establishing electrical connection with contact targets as defined in Claim 20, wherein the cut-out is formed at one side of the contactor and width of the contactor at the cut-out is substantially the same as width of the groove of the contactor adapter.

24. A probe contact assembly for establishing electrical connection with contact targets as defined in Claim 20, wherein the contactor adapter further includes a stopper which engage with a step formed in the slot of the contactor carrier to determined a vertical position of the contactors when the contactor adapter is inserted in the slot.