JP3051599B2 - Semiconductor chip test socket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor chip test socket, and more particularly, to a semiconductor chip test socket used for electrically inspecting a bare chip IC cut from a wafer.

[0002]

2. Description of the Related Art A semiconductor chip test socket is an IC.
The bare chip is held inside to protect it, and is transported into a test apparatus for use in a burn-in test or the like of the IC. Although it is also called a chip carrier because it is used for such transport, it is not limited to a mere transport jig, but is intended to make electrical contact in an operation test easy and reliable. For this reason, it is necessary to support the electrical coupling by matching between the fine and narrow pitch pads of the IC chip (semiconductor chip) and the contact pins with a not so fine and wide pitch on the tester side. .

As a conventional semiconductor chip test socket, there is one in which a probe card and a small XYZ stage are combined (Nikkei Micro Devices, April 1993).
Monthly issue P41). In this method, a bare chip of an IC is placed on a stage, the XY movement mechanism of the stage is operated with respect to the pad of the IC chip, the pin end of the probe card is aligned, and the Z movement mechanism of the stage is operated to perform probe operation. The pins of the card are brought into contact with the IC chip. Contact terminals with contact pins on the tester side are provided on the outer peripheral portion of the upper surface of the probe card, and these are respectively connected to corresponding pins of the probe card by wiring. This supports the matching and electrical coupling functions described above.

[0004]

Such a conventional semiconductor chip test socket follows the conventional manual prober technology, and it can be said that only the mechanical section is made independent. For this reason, miniaturization is difficult and at most 10c
The m-square is the limit and is not suitable for use as a chip carrier. Also, because many precision parts are required,
The height is increased, and the pin support mechanism is complicated. further,
Adjustment of the height of the probe pin to be brought into contact with the IC chip must be performed for each pin by bending the elastic pin until it is plastically deformed. Therefore, it is difficult to make the height uniform and the adjustment operation is complicated and difficult. Therefore, not only productivity but also maintainability (maintenance) are not good.

[0005] In this case, even if it can be used experimentally or on a test basis, it cannot meet the expected increase in the demand for testing bare IC chips in the future, which is a problem. SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem of the prior art, and realizes a semiconductor chip test socket suitable for IC bare chip testing and having a configuration in which the pin heights are aligned with high precision. Is to do.

[0006]

To achieve this object, a semiconductor chip test socket according to the present invention has the following structure.
Attaching to the material of the test contact pin on the substrate layer or
Forming a first metal layer of a material to be bonded;
Second gold provided to the test contact pin
A metal layer is formed by plating to cover the second metal layer.
Cover all parts other than the tip used for the test contact pins.
A substrate film and a first metal layer.
Multiple wiring paths formed by separating the
Turn and connect to the middle or rear end of these wiring patterns.
Flexible base based on film with contact terminals
A plate, a frame that directly or indirectly receives and holds a semiconductor chip on which an integrated circuit is formed, and each of the contact terminals is arranged at a position to receive a contact pin or a probe pin from the outside; A clamper for fixing the flexible substrate to the frame so that each of the tip portions comes into contact with each of the pad portions, and directly or indirectly pressing a portion of the tip portion near the tip with the clamper. Thus, a contact force between the pad portion and the tip portion is obtained.

[0007]

In the semiconductor chip test socket of the present invention having such a configuration, the frame for fixing the flexible substrate can hold the semiconductor chip (hereinafter referred to as IC chip) inside. Further, in relation to the flexible substrate, the contact terminals on the flexible substrate are arranged at positions where the contact pins or probe pins on the tester side are received. As a result, matching with respect to a difference in pin pitch between the IC chip and the tester is achieved, electrical connection is supported, and a bare chip test can be performed.

Further, a flexible substrate having a wiring pattern having a tip portion as a contact pin for contacting an IC chip is manufactured based on a plating process .
One, the contact pin contact surface is plated with a metal layer
The surface from which the metal layer has been peeled off is used above. This
As the height of the tip of the probe pin is the same,
The contact between the IC pad and the probe pin is uniform
You. As a result, when they come into contact,
In addition, each probe pin can be pressurized by a spring,
Mechanisms and devices that give a large bias to the probe pin
It becomes unnecessary and can be incorporated as a probe needle into a small one.
And pressurization with a clamper is sufficient.
High contact pressure can be obtained. As a result, a small chip
A prober as a test socket can be realized.
Therefore, even when the number of pins is increased at a narrow pitch, the contact pins on the IC chip have the same height with high accuracy. Moreover,
Since a configuration is employed in which the contact portion between the pad portion and the tip portion is obtained by pressing a portion of the tip portion near the tip with a clamper, sufficient overdrive and contact pressure can be ensured even with a thin pin. . This eliminates the need for difficult pin-to-pin height adjustment, and eliminates or makes it extremely easy to adjust the pin height. Therefore, the semiconductor chip test socket of the present invention is suitable for testing a bare chip of an IC, and the pin heights are aligned with high precision.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a chip carrier as one embodiment of a semiconductor chip test socket of the present invention will be described in detail with reference to the drawings. FIG. 1A is a perspective view of the external appearance of a chip carrier in a state where the IC chip 30 is mounted and assembled, and FIG.
FIG. 3 is an enlarged cross-sectional view of a contact portion with the contact. FIG. 2 is a development view of the chip carrier in that state. FIG. 3 is an enlarged schematic view of the flexible substrate.

Here, reference numeral 20 denotes a frame main body which forms a main part of the frame, 21 denotes a positioning plate having an opening at the center, 2
2 is a flexible substrate having a plurality of wiring patterns, 2
3 is a clamper for pressing the flexible substrate 22 from above,
Reference numeral 24 designates the clamper 23 by the spring
It is a stop plate to be fixed to. Reference numeral 25 denotes a lower plate as a holding plate for holding the IC 30 inserted from below, from below, and is attached to the frame main body 20 by bolts 26.

The flexible substrate 22 has a plurality of wiring patterns (see 14 and the like in FIG. 3), and the details of the manufacturing method will be described later. The respective tips (see 14d in FIG. 3) of these wiring patterns are exposed without being supported by the substrate, and are used as IC chip-side contact pins. Wiring pattern 1
The contact terminal (1 in FIG.
4e), and the contact of the tester with the contact pins can support the electrical connection between the IC chip 30 and the tester.

The flexible substrate 22 has at its center a substantially rectangular opening slightly larger than the contact pads of the IC chip (see 15b in FIG. 3). And each tip part 14d etc. protrude along each side of this opening 15b. By having this opening, the tip part functions as an IC-side contact pin, and the contact state between the tip of the tip part 14d and the contact pad of the IC 30 can be monitored. Note that the flexible substrate 22 can be easily deformed without being damaged.
A cut may be provided at the corner of the opening.

Further, the positions of the tips are provided corresponding to the arrangement of the contact pads of the IC chip 30, and the contact terminals at a wide pitch corresponding to the arrangement of the tester-side contact pins are provided at the rear end of the wiring pattern connected thereto. Is provided. As a result, it is possible to achieve matching between the fine, narrow-pitch pads of the IC chip and the not-so-fine, wide-pitch contact pins on the tester side. In addition, IC
If the contact pads of the chip 30 are not provided on all four sides but only on some of them,
It is sufficient to provide the tip portion at least for two or more opposing sides. If there are tip portions on two opposing sides, the IC chip can be stably pressed and held.

The clamper 23 has a tip 14
A through-thread 23a is provided in a portion near d. A screw is screwed into the through female screw 23a, and the male screw presses a portion of the flexible substrate 22 near the distal end portion 14d. When the male screw is rotated in this state,
The inclination of the flexible substrate 22 can be adjusted by changing the pushing amount of the flexible substrate 22. Thus, the male screw inserted into the internal female screw 23a of the clamper 23 functions as a height adjusting screw of the distal end portion 14d.

In this embodiment, the clamper 23
Between the plate and the flexible substrate 22
b and an insulating sheet 23c. Then, the height adjusting male screw pushes the flexible substrate 22 via the clamp plate 23c. By interposing the clamp plate in this way, it is possible to prevent local deformation of the soft flexible substrate 22 and easily adjust the inclination of the distal end as a whole. In this case, it is sufficient if at least two or more adjustment screws are provided on each side, and it is sufficient if the clamp plate 23c is provided in a portion near the tip portion 14d.

The clamp plate 23c has a thickness of 1
A copper plate of about mm is used, which has a mechanical function as a clamp mechanism and also has an electrical function as a ground plate for the wiring pattern 14 and the like. However, if the processing accuracy of the frame body 20, the clamper 23, and the like is sufficiently high, it is sufficient to directly press the portion of the distal end portion 14d close to the distal end with the clamper 23 without providing such an adjustment screw. When the clamper 23 is not an insulator, it may be held down via an insulating sheet. Which configuration to use is determined by comparing the processing cost and the adjustment cost, but in any case, the pin heights can be aligned with high accuracy.

A procedure for inserting the IC chip 30 into a chip carrier having such components will be described. The positioning plate 21 is placed on the mounting portion of the frame body 20. The flexible substrate 22 is placed on this with the openings aligned. The insulating sheet 23c and the clamp plate 23b are overlaid on the flexible board 22.
In addition, on top of the opening, also align the opening,
The clamper 23 is placed, and the stopper plate 24 is locked to the frame body 20 from above. The stopper plate 24 is a kind of leaf spring whose central portion is bent, and presses and fixes the clamper 23 here.

All of these parts are provided with openings corresponding to the positions where the ICs 30 are inserted. Thereby, the IC 30 inserted later from below through the opening can be observed. The clamper 23 and the stopper plate 24 have a substantially rectangular shape when viewed in plan, and the contact terminals of the flexible substrate 22 are assembled so as to be located outside the longer sides (reference numerals in FIG. 1A). 22). Thereby, the contact terminal can receive the contact pin or the probe pin which comes in contact from above the outside.

The lower surface of the clamper 23 is slightly inclined near the opening. As a result, the distal end of the flexible substrate 22 is slightly inclined downward. The IC chip 30 is placed on the lower plate 25 facing upward, and in this state, the lower plate 25 is temporarily fixed to the frame main body 20 from below. Then, the distance between the tip of the tip of the flexible substrate 22 and the upper surface of the lower plate 25 is set slightly smaller than the thickness of the IC chip 30, and the tip of the flexible substrate 22 corresponds to the contact pad of the IC 30. , The IC 30 is lightly held between the tip and the lower plate 25.

At this stage, while checking the positional relationship between the tip of the tip and the contact pad of the IC 30 by monitoring the inside through the upper opening, the positioning plate 21 is moved or a needle-shaped jig is used. The IC 30 is moved to perform alignment so that the corresponding tip portion and the contact pad coincide with each other. When the dicing accuracy of the IC 30 is sufficiently good and the relative position between the chip outer shape and the contact pad is stable, the positions of the positioning plate 21 and the flexible substrate 22 are previously adjusted to fix them. It is good to assemble. In this case, since the opening of the positioning plate 21 corresponds to the outer shape of the IC chip 30, the positioning work performed while monitoring the IC 30 becomes unnecessary, and the insertion work can be performed efficiently.

When the positioning is completed, the lower plate 25 is fixed to the frame body 20 in full scale. As a result, the middle of the inclined front end portion is formed by the clamper 23 or the clamp plate 2.
When pressed by 3c, a so-called overdrive is applied to the tip portion, and this is securely contacted with the contact pad to establish a line of electrical coupling (see FIG. 1B). If necessary, the inclination of the entire distal end portion is adjusted with an adjusting screw so that the contact force of each distal end portion is substantially uniform. This state is very similar to the state where the IC chip 30 is mounted on a so-called multi-chip module or the like. Therefore, it is possible to test the operation state of the IC almost in the mounted state, which contributes to the improvement of the reliability of the test result.

In the case where a bump is provided on the contact pad portion of the IC 30 or on the tip of the flexible substrate 22, overdrive is performed within the range of the height of the bump. You don't have to. The chip carrier assembled in this way is a small chip carrier of about 1 inch square (about 2.5 cm square), and is most suitable for a dynamic burn-in test or the like.

Finally, a method of manufacturing the flexible substrate 22 will be described. FIG. 4 is a schematic cross-sectional view in each step. This is for illustrative purposes, and in fact, IC
Generally, the number of the side contact pins is several tens to several hundreds, and the pitch is not always constant. In the following, IC
The side contact pins are simply called pins, the wiring patterns are called patterns, and the pins 14d and the patterns 14e are called pins 14 together. The entirety of the pin 14 and the like and the film 15 is referred to as a pin film body 22.

The pin manufacturing process mainly includes a first metal layer forming process, a resist pattern forming process which is the first half of the plating process, and a second metal layer as the second half of the plating process. It comprises an electroplating step to be formed, a film deposition step, a peeling step which is the first half of the separation step, and a removal step which is the second half of the separation step. The pin 14
Is preferably Ni from the viewpoint of strength and toughness. further,
Pd or the like may be included. When importance is placed on conductivity, gold is preferably coated to increase conductivity. Alternatively, beryllium copper may be used instead of Ni. Hereinafter, each step will be described in this order.

In the step of forming the first metal layer, a thin copper layer 11 as a first metal layer is formed on a stainless steel plate 10 as a substrate layer by electrolytic plating. The use of copper as the first metal layer is excellent in the adherence to the Ni pins 14 and the like, and that the adherence to the stainless steel plate 10 is weaker than the adherence of the film 15 to the Ni pins 14 and the like. Because it is a good conductor. Since copper is superior in conductivity to stainless steel, electrolytic plating is performed quickly and uniformly. The stainless steel plate 10 is mirror-finished and has a flat and smooth surface.

The step of forming a resist pattern includes the steps of:
Is coated with a photoresist 12 (see FIG. 4A), and is exposed through a mask 13 (see FIG. 4B). Thus, the pattern corresponding to the mask 13 is transferred to the resist 12. Further, this is developed to form a resist 12 having a pattern corresponding to the mask 13, and a resist mask is applied on the copper layer 11 (see FIG. 4C).

In the electrolytic plating step, the air gap 12a above the copper layer 11 which appears in the portion where the resist mask is not
Next, Ni is formed by attaching and growing by electrolytic plating (see FIG. 4D). After the completion of the Ni plating, the resist 12 is removed and the mask is removed (see FIG. 4D). The Ni layer thus formed is provided for the pins 14.

In the film deposition step, a polyimide film 15 is deposited on the Ni layer (14) to cover the pattern 14e and the like other than the portions provided for the pins 14d. Specifically, thermocompression bonding is performed from above the film 15 with a jig having a flat pressing surface with the bonding plastic 15a interposed therebetween (FIG. 4).
(F)). This allows the plastic side to be pin 1
4, the fine irregularities and thickness unevenness existing on the upper surface of the Ni layer (14) are absorbed. As a result, the thickness of the pin film body 22 can be made uniform.

The film 15 has an opening 15b (see FIG. 3). The opening 15b is adhered to the pin 14d. As a result, the pins 14d are supported by the film 15 in a cantilever state, and the film 15 is used as a substrate that collectively supports the pins 14d and the like.

In the peeling step, a portion composed of the copper layer 11, the Ni layer (14), and the film 15 is separated from the stainless steel plate 10 by being peeled between the stainless steel plate 10 and the copper layer 11. As described in the description of the step of forming the first metal layer, since the adherence force to the stainless steel plate 10 is weaker than the adherence force of the film 15 to the Ni pins 14 and the like, these are not damaged without damaging the film 15 and the like. Separates easily.

In the removing step, the copper layer 11 is removed from the Ni layer (14) by wet etching. Since the copper layer 11 is thin, the Ni layer (14) is formed using an etching solution having a high selectivity.
The copper layer 11 is removed without impairing the structure. As a result, a portion composed of the film 15 and the pins 14 is separated from the stainless steel layer 10 and the copper layer 11. The cross section of the IC-side contact pin 14 manufactured in this manner is substantially rectangular (typically 50 μm × 50 μm). Therefore, when contacted by being bent into a cantilevered shape,
The contact pressure and the overdrive capability that are larger than those having a triangular cross section or a circular cross section can be exhibited. In addition, the bending rigidity in the oblique direction is large, and it is unlikely to bend obliquely. Therefore, there is no inconvenience (about 80 μm) even if the pitch is reduced.

Further, the side surface 1 for contacting the IC chip
4a, 14b, and 14c have the same height corresponding to the flat surface of the stainless steel plate 10.
When the pin film body 22 is held between the frame body 20 and the clamper 23 and the like and the pin 14d of the pin film body 22 is pressed by the clamper 23, the thickness of the pin film body 22 becomes one. Since the heights of the contact surfaces 14a, 14b, 14c, etc. are the same, there is no need to perform height adjustment for each pin.
The height of the pins is the same. It is also possible to use the pin film body 22 in an inverted state. In this case, the side surface opposite to the side surfaces 14a, 14b, and 14c is a contact surface. The height of the pins is almost the same.

Further, the side surfaces 14a, 14b and 14c to which a tensile stress is applied when they come into contact with the IC chip have a smooth surface state corresponding to the smooth surface of the stainless steel plate 10. Therefore, the fatigue strength affected by the surface smoothness increases, and the number of times of repeated use increases. Also, the flexible substrate 22 having such pins
The film 15 functions as a support plate for supporting the tip portion 14d of the pin. Therefore, a small chip carrier can be configured by providing upper and lower plates such as stopper plates in the height direction.

It is particularly preferable that the opening of the clamper 23 is slightly smaller than the opening of the positioning plate 21. Thus, the upper clamper 23 of the flexible board 22 is used as the first clamper, and the lower alignment plate 2 of the flexible board 22 is used as the first clamper.
Assuming that 1 is a second clamper, a portion of the first clamper 23 that presses the flexible substrate 22 and is closest to the distal end of the distal end portion 14d is a portion of the second clamper 21 that fixes the flexible substrate 22. Therefore, it is closer to the tip of the tip 14d than to the portion closest to the tip of the tip 14d. As a specific example, the former is 5 mm from the tip
The latter is about 10 mm from the tip. This and the flexibility of the flexible substrate 22 make it possible to further secure the contact force and facilitate the height adjustment.

[0035]

As can be understood from the above description, in the semiconductor chip test socket of the present invention, the front ends of the plurality of wiring patterns are exposed without being supported by the substrate, and the contact terminals are formed on the rear end side. A flexible substrate having a semiconductor chip, a frame for holding the semiconductor chip, and a clamper for fixing the flexible substrate to the frame so that the tip of the semiconductor chip contacts the pad of the semiconductor chip. To obtain the contact force between the pad and the tip. This has the effect of realizing a semiconductor chip test socket that is suitable for testing an IC bare chip and that has a configuration in which the pin heights are aligned with high precision.

[Brief description of the drawings]

FIG. 1 shows a chip carrier as one embodiment of a semiconductor chip test socket having a configuration of the present invention;
(A) is a perspective view of the appearance, and (b) is an enlarged cross-sectional view of a contact portion with an IC chip.

FIG. 2 is a development view of the chip carrier.

FIG. 3 is an enlarged schematic view of a flexible substrate.

FIG. 4 is an explanatory diagram of a manufacturing process of the flexible substrate.

[Explanation of symbols]

 Reference Signs List 10 stainless steel plate 11 copper layer 12 photoresist 13 photomask 14 pin 15 film 20 frame body 21 positioning plate 22 flexible substrate 23 clamper 23a through female screw 23b clamp plate 23c insulating sheet 24 stopper plate 25 lower plate 26 bolt 30 IC chip

 ──────────────────────────────────────────────────続 き Continuing the front page (72) Inventor Etch Dun Higgins United States of America, Arizona, Gilbert, Suite 101, North Stick Boulevard 1478 Fresh Quest Corporation (72) Inventor Pete Normington United States of America, Arizona, Gilbert , Sweet 101, Nostec Boulevard 1478 Inside the Fresh Quest Corporation (56) References JP-A-3-112143 (JP, A) JP-A 4-233480 (JP, A) JP-A-62-188396 (JP, A) JP-A-61-57867 (JP, U)

Claims (4)

(57) [Claims] An unmasked first metal layer is formed on a substrate layer, the first metal layer being made of a material that adheres to or is bonded to a material of a test contact pin, and a mask is formed on the first metal layer.
A second metal layer serving as the test contact pin was formed on a portion by plating, and the mask was removed.
The deposited film which covers the other tip is subjected to the test contact pin on the second metal layer
The film and the second metal layer obtained by separating a portion composed of a film and the second metal layer from a portion composed of the substrate layer and the first metal layer.
And a plurality of wiring patterns formed Ri, further a flexible substrate based on the film have a contact terminal in the middle or rear end side of this <br/> et wiring pattern, an integrated circuit is formed A frame for directly or indirectly receiving and holding the semiconductor chip, and each of the contact terminals is arranged at a position for receiving a contact pin or a probe pin from the outside; And a clamper for fixing the flexible substrate to the frame so that the portions are in contact with each other, wherein the pad portion and the tip portion are directly or indirectly pressed by the clamper on a portion of the tip portion near the tip. A semiconductor chip test socket characterized by obtaining a contact force. 2. The semiconductor chip test socket according to claim 1, wherein said clamper is a first clamper, a second clamper is provided on said frame, and said second clamper is said first clamper. The flexible substrate is fixed to the frame with the flexible substrate interposed between the clamper and a portion of the first clamper that presses the flexible substrate and a portion of the first clamper that is closest to the tip of the tip is the second portion. A semiconductor chip test socket, wherein a portion of the clamper to which the flexible substrate is fixed and which is closer to the tip of the tip than a portion closest to the tip of the tip. 3. The semiconductor chip test socket according to claim 1, wherein a female screw is provided at a portion of the clamper near the distal end, and the female screw is screwed to the female female screw. A socket for semiconductor chip test, wherein the socket is inserted and the male screw pushes the flexible substrate as a height adjusting screw at the tip. 4. The semiconductor chip test socket according to claim 3, wherein a clamp plate is provided between the clamper and the flexible substrate at least at a portion near the tip, and the male screw is provided on the clamp plate. A socket for testing the semiconductor chip, wherein the flexible substrate is pushed through the socket.