JP2001021584A - Vertical probe card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical probe card having excellent thermal stress resistance and high rigidity by reinforcing support plates, while enhancing the reliability of probe testing accuracy by preventing movement of a needle contact end, and suited for application to a multiple pin configuration used at a high temperatures, particularly a DRAM. SOLUTION: In this vertical probe card, a number of probing needles 4 are arranged between both upper and lower support plates 5, 3, and each needle is connected at its connecting end 4a to a lead part 7 via a guide hole 14 provided in the upper support plate 5 and has its contact end 4b passed through and supported against a guide hole 13 in the lower support plate 3. Reinforcing plates 20 made from carbon fiber reinforced plastic(CFRP) are bonded to both the front and back faces of the base 21 of the lower support plate to form the lower support plate 3 integrally, and window hole parts for exposing the guide hole 13 are bored in the reinforcing plates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical probe card, more specifically, a structure in which a large number of probe needles are arranged between upper and lower support plates, and the needles are configured to be in vertical contact with electrode pads on the surface of a semiconductor wafer. The present invention relates to a probe card for transmitting and receiving an electric signal to and from the pad.

[0002]

2. Description of the Related Art A vertical probe card can reduce the length and length of a probe as compared with a cantilever type in which a large number of probe needles are horizontally arranged on the bottom surface using epoxy resin. It is widely used because of its advantages such as a uniform diameter, less damage to electrode pads, and an increase in the degree of freedom in electrode pad arrangement. In this vertical type, generally, a large number of probe needles are arranged between upper and lower support plates, and connection ends of the needles are inserted into and supported by guide holes provided in an upper support plate, and are connected to electric signal input terminals. In addition, a configuration is known in which the other contact end is inserted and supported in a guide hole of a lower support plate. As the upper and lower support plates, a plastic thin plate of polyimide or the like is used. In addition, recent semiconductor wafer chips have a large number of electrodes, and correspondingly, probe cards are also required to have a large number of pins by increasing the number of probe needles. In particular, the arrangement pitch of the needle contact ends, that is, the interval between the guide holes of the lower support plate is as small as about 0.1 mm.

[0003]

However, conventionally, DRA
When performing a high-temperature test at a temperature of 85 to 150 ° C. using the above-described vertical probe card as in a probe test of a memory device such as M, distortion (bending) is caused by the coefficient of thermal expansion of the lower support plate. In some cases, the pitch between the guide holes changes, and the position of the needle contact end shifts. This misalignment of the needle contact end
A misalignment occurs between the set contact end and the chip electrode pad of the semiconductor wafer, which causes an inspection error such as a contact failure. Particularly in a multi-pin configuration where the electrode pitch is small, a slight misalignment occurs. This also causes a contact failure and significantly reduces the reliability of the probe test.

In order to solve the above problem, a material having a low coefficient of thermal expansion, for example, a ceramic or an invar alloy may be used as the upper and lower support plates, especially the lower support plate. However, in that case, in order to protect the needle contact end and secure the insulating layer, an insulating coating such as a resin must be applied to the inner surface of the guide hole in which the needle contact end slides, Therefore, the guide hole diameter of the material of the lower support plate itself becomes twice as large as the coating layer,
In view of strength, there is a problem that the pitch of the holes cannot be reduced correspondingly and multi-pinning cannot be achieved.

In view of the above-mentioned circumstances, the present invention reinforces the support plate to provide excellent heat stress resistance and high rigidity, and to reduce the pitch deviation of the guide holes, that is, the position deviation of the needle contact end. Probe card, especially DRA, which prevents and improves the reliability of probe test accuracy
It is an object of the present invention to provide a vertical probe card suitable for application to a multi-pin configuration used at high temperatures such as M.

[0006]

According to the present invention, in a vertical probe card, a reinforcing plate made of carbon fiber reinforced plastics (CFRP) is adhered to both the front and back surfaces of the lower support plate to integrally form the same. The reinforcing plate has a window hole for exposing the guide hole. According to the present invention, even if the lower support plate is a plastic thin plate similar to the conventional one, even if it is used under high temperature, its heat stress resistance and high rigidity are improved by the reinforcing plate made of CFRP, Deformation and thermal expansion are suppressed, and pitch deviation of the guide holes can be prevented. The above-mentioned CFRP is not limited to the weaving structure such as biaxial woven fabric, triaxial woven fabric, and four-axial woven fabric as long as the woven fabric is arranged to have pseudo-isotropy.
In consideration of the cost and the reinforcing effect, it is preferable to use a biaxial woven fabric which is inexpensive to manufacture.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of a probe card 1 in a sectional view. In the figure, a probe card 1 is fixed to a probe bar (not shown) and can move relative to a wafer 2 to be inspected fixed on a chuck (not shown). The probe card 1 includes a lower support plate 3, an upper support plate 5 integrated with the lower support plate 3 via a spacer 12,
It comprises a needle 4, an electrical connector 6 and a wiring board 8.

The lower support plate 3 has a number of connection holes 13 opened in parallel, and the upper support plate 5 also has a number of connection holes 14 opened in parallel. The needle 4 is located between the upper support plate 5 and the lower support plate 3, is slidably inserted into the coupling holes 14, 13 of the upper and lower support plates, and is located above the upper support plate 5 and the lower surface of the lower support plate 3. Both ends protrude slightly on each side. The electrical connector 6 has a lead 7 that is in electrical contact with the upper end of the needle 4 protruding from the coupling hole 14 on the upper surface of the upper support plate 5 and transmits an electric signal. The wiring board 8 supports the upper and lower support plates 5 and 3 and the electrical connector 6 and is fixed to a prober (not shown).

The coupling holes 13 of the lower support plate 3 are arranged in accordance with the arrangement of the electrodes (pads) 15 on the wafer 2 to be inspected, and are inserted into the coupling holes 13 in the electrodes 15 on the wafer 2 at the time of inspection. The lower tip of each needle 4 can individually obtain electrical continuity with each electrode. Needle 4 above
Is deformed when it comes into contact with the electrode 15 and can be pushed up by approaching the electrode 15 at the time of inspection, exerts an appropriate spring property, and is connected to the end faces of the leads 7 aligned with each other through the coupling hole 14 of the upper support plate 5. Contact and electrical conduction. The electrical connector 6 is made of an insulating material such as plastic, and has a hole drilled at a position corresponding to the coupling hole 14 of the upper support plate 5. An electrode is formed for contact with the substrate 4 to obtain conduction. The wiring board 8 is a multi-layer wiring board based on a general epoxy resin containing glass fiber.
11 (generally a seat for contacting a spring probe of the performance board) is arranged and connected to the tester via the performance board. Also, the wiring board 8
Is provided with an electrode 9 for connection to the lead 7, and the electrode 9 and the electrode 11 are connected to each other through a through hole or a via hole and an internal wiring pattern 10.

The lower support plate 3 is provided with reinforcing plates on both the front and back surfaces of a base material 21 made of an insulating thin plate such as plastic.
20 are integrally formed by bonding, the details of which will be described with reference to FIGS. The base material 21 of the lower support plate includes a plurality of chips 31 formed on the semiconductor wafer 2 (in FIG.
a, 31b, 31c, 31d), a rectangular plastic part of a size to be tested at the same time and a peripheral part fixed by the spacer 12, and a 0.5 mm thick polyimide plastic thin plate is used. An example is shown. As an example, the semiconductor wafer 2 is one on which chips 31 for a DRAM are formed, and four adjacent chips to be tested at the same time (one cell in the wafer 2 in FIG. 3 indicates one chip). Are 31a to 31d. As an example of the arrangement of the electrode pads of each of the chips 31a to 31d, a form is shown in which a large number of electrode pads 32a are formed at a predetermined pitch in the center and electrode pads 32b are formed at each corner.

The chip 31a is provided on the base material 21 of the lower support plate.
Guide holes 1 corresponding to the respective electrode pads 32a, 32b
3. Specifically, the guide hole rows 13a and 13b are pierced. The guide hole array 13a is formed by drilling a large number of electrode pads 32a arranged in parallel at a predetermined pitch. By the way, the guide holes 13a, 13
The hole diameter of b is 0.07 mm, and the pitch of the guide hole array 13a is 0.1 mm. In FIG. 3, counterboring is performed near the guide holes 13 a and 13 b of the base member 21, but this is to limit the length of the hole serving as the sliding portion, and the counterbore need not be provided.

The two reinforcing plates 20 are provided on the base material 21 of the lower support plate 3.
Are bonded to each other with the same structure on the front and back sides, and for convenience of description, both will be described using the same reference numerals. The reinforcing plate 20 is made of CFRP made by impregnating a thermosetting resin (for example, an epoxy resin) into a carbon fiber woven fabric having a thickness of about 0.3 mm thinner than the base material 21 and having the same shape as the base material 21. Sheet. The reinforcing plate 20 has an elongated window hole portion 34a corresponding to the guide hole rows 13a and 13b of the base material 21.
Then, the rectangular window holes 34b to 34d are opened in advance. Specifically, the window hole portion 34a is connected to two adjacent chips 31a.
The openings 31b and 31c and 31d are formed in a long shape to expose the guide holes 13a and 31a facing the electrode pads 32a and 32a, and the window holes 34b are formed in the electrode pads 32b at the corners of the chips 31a to 31d. Is opened so as to expose the guide hole 13b opposed to. The window hole 34c is formed in the guide hole 13 facing the adjacent electrode pads 32b of the two adjacent chips.
The openings are opened so as to expose the b and 13b, and the window holes 34d are formed in the adjacent electrode pads 32b, 32b and 32 of the four adjacent chips.
Opening is made so as to expose the guide holes 13b, 13b, 13b, 13b opposed to b, 32b. The window holes 34a and 34b
34d is for preventing the upper and lower portions of the guide holes 13a and 13b of the base material 21 from being closed, and since the carbon fibers of the reinforcing plate 20 are conductive, the needle 4 inserted into the guide holes is used.
This prevents electrical conduction between the guide hole wall and the sliding portion 4b.

The reinforcing plate 20 is made of a prepreg made of CFRP, and is formed by punching or cutting into a predetermined shape from a CFRP sheet in a prepreg state.
Open ~ 34d. These window holes 34a, 34b to 34d are CF
By opening from the RP prepreg, the window holes and the like can be easily processed.
a, 34b-34d, the opening of the reinforcing plate 20 from the CFRP sheet.
It may be processed at the same time when the 13 is formed by punching or cutting. Further, the carbon fiber of CFRP of the reinforcing plate 20 is illustrated as a case where the carbon fiber is woven into a biaxial woven fabric composed of warps and wefts.

The reinforcing plate 20 is provided in a prepreg state on each of the front and back surfaces of the base material 21 of the lower support plate.
Polymerization is performed so that a and 13b are exposed from the window holes 34a and 34b to 34d. Thereafter, the substrate is heated and pressed to adhere to the base material 21 to produce a lower support plate 3 having an integral structure. Thus,
The lower support plate 3 is excellent in heat stress resistance and high rigidity is secured by bonding the reinforcing plate, and the pitch of the guide holes 13 is stabilized even at a high temperature, and the generation of distortion is prevented. Further, even when there is a temperature difference between the upper and lower surfaces of the lower support plate 3 due to the low coefficient of thermal expansion of the carbon fiber, the lower support plate 3 has no distortion such as warpage and the positional stability of the guide holes 13 is maintained. Further, heat generation due to conduction current of the needle 4 and temperature rise due to heat conduction of the needle 4 from the wafer to be inspected can be suppressed by the thermal conductivity of the carbon fiber.

In the above embodiment, the case where the reinforcing plate 20 is provided only for the lower support plate 3 has been described. However, the present invention is not limited to this.
The reinforcing plate 20 'made of RP may be bonded, so that the support structure of the needle 4 can be further stabilized. Further, in the embodiment, the reinforcing plate 20 is a thin plate reinforced with a carbon fiber woven fabric, but the reinforcing carbon fiber may be any high-rigidity and low-thermal-expansion fiber such as Kepler. It is not limited to.

[0016]

According to the present invention, the lower support plate is provided with high rigidity and the heat stress resistance is improved by bonding the CFRP reinforcing plate. The occurrence of pitch deviation of the guide holes can be prevented. Therefore, the displacement of the probe contact ends arranged on the lower support plate is eliminated, and the alignment accuracy with the electrode pads formed on the semiconductor wafer is ensured. Accuracy can be improved and reliability can be secured. Moreover, since the lower support plate can be made of the same plastic material as before without using ceramic or invar, a highly reliable probe card can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an outline of a vertical probe card of the present invention.

FIG. 2 is a plan view showing a correspondence between a lower support plate and a semiconductor wafer.

FIG. 3 shows an exploded perspective view of a lower support plate together with a semiconductor wafer.

[Explanation of symbols]

1: Probe card 3: Lower support plate
4: Needle 5: Upper support plate 8: Wiring board 13, 13a, 13b: Guide hole 20: Reinforcement plate on front and back of lower support plate 21: Base material of lower support plate 34a, 34b to 34d: Window hole

[Procedure amendment]

[Submission date] June 20, 2000 (2006.2.
0)

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

According to the present invention, in a vertical probe card, a reinforcing plate made of carbon fiber reinforced plastics (CFRP) is adhered to both the front and back surfaces of the lower support plate to integrally form the same. The reinforcing plate has a window hole for exposing the guide hole. According to the present invention, even if the lower support plate is a plastic thin plate similar to the conventional one, even if it is used under high temperature, its heat stress resistance and high rigidity are improved by the reinforcing plate made of CFRP, Deformation and thermal expansion are suppressed, and pitch deviation of the guide holes can be prevented. The above-mentioned CFRP is not limited to the weaving structure such as biaxial woven fabric, triaxial woven fabric, and four-axial woven fabric as long as the woven fabric is arranged to have pseudo-isotropy.
In consideration of the cost, the reinforcing effect, and the number of assembling steps , it is preferable to use an inexpensive biaxial woven fabric.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G011 AA17 AA21 AB06 AB07 AC14 AE03 AF07 4M106 AA01 AA02 BA01 BA14 CA60 DD10

Claims (1)

[Claims] 1. A large number of probe needles are arranged between upper and lower support plates, and connection ends of the needles are inserted into and supported by guide holes provided in an upper support plate, and are connected to electric signal input terminals. In a vertical probe card in which the other contact end is inserted into and supported by a guide hole of a lower support plate, a reinforcing plate made of carbon fiber reinforced plastics (CFRP) is adhered to both the front and back surfaces of the lower support plate. A probe card, wherein the reinforcing plate has a window hole for exposing the guide hole.