JPH0783076B2 - 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 out from a wafer.

[0002]

2. Description of the Related Art A semiconductor chip test socket is an IC
The bare chip is held inside so as to be protected, and is transferred into a test device for a burn-in test of the IC. Although it is also called a chip carrier because it is used for such transportation, it is not limited to a mere transportation jig, but it is for easily and surely making electrical contact in an operation test. Therefore, it is necessary to support the electrical coupling by matching between the fine and narrow pitch pads of the IC chip and the contact pins on the tester side, which are not so fine and have a wide pitch.

As a conventional semiconductor chip test socket, there is one in which a probe card and a small XYZ stage are combined (Nikkei Microdevice, April 1993).
(See P41 of the monthly issue). This is because the bare IC chip is placed on the stage, the XY moving mechanism of the stage is operated with respect to the pad of this IC chip to align the pin tip of the probe card, and the Z moving mechanism of the stage is operated to operate the probe. The pins of the card are brought into contact with the IC chip. Contact terminals for contact pins on the tester side are provided on the outer peripheral portion of the upper surface of the probe card, and each of these is connected to the corresponding pin of the probe card by wiring. This supports the matching and electrical coupling features described above.

[0004]

Such a conventional semiconductor chip test socket follows the technique of the conventional manual prober, and it can be said that only its mechanical portion is independent. For this reason, downsizing is difficult and at best 10c
It is not suitable for use as a chip carrier because the limit is about m square. Also, since many precision parts are required,
The height is high, the pin support mechanism is complicated, the productivity is low, and the cost is high. Therefore, even if it can be used experimentally and experimentally, if it is left as it is, it is not possible to meet the expected increase in the demand for testing bare chips of ICs, which is a problem. An object of the present invention is to solve the above-mentioned problems of the prior art, and it is possible to test the bare chip of the IC in a state close to the mounted state, and further, the height is small, the size is high, and the productivity is high. It is to realize a semiconductor chip test socket having a configuration.

[0005]

The structure of the semiconductor chip test socket of the present invention for achieving this object is as follows.
A flexible substrate having a plurality of wiring patterns, each of which has its tip end exposed without being supported by the substrate and having a contact terminal in the middle or on the rear end side, and a semiconductor chip having an integrated circuit formed thereon Each of the contact terminals having a through opening is arranged at a position for receiving a contact pin or a probe pin from the outside, and each of the tip portions is in contact with the respective pad portions of the semiconductor chip in the through opening. A frame for fixing the substrate and a semiconductor chip inserted through the opening of the through opening on the side opposite to the side where the contact pin or the probe pin comes into contact are held in the through opening by contacting the lower surface of the semiconductor chip. A holding plate,
The distance from the tip of the tip portion to the semiconductor chip contact surface of the holding plate is the same as or slightly smaller than the thickness of the semiconductor chip.

[0006]

In the semiconductor chip test socket of the present invention having such a structure, in the inner portion, the distance between the tip of the tip of the flexible substrate fixed to the frame and the contact surface of the holding plate is the same. The thickness is equal to or slightly smaller than the thickness of the IC chip (hereinafter referred to as an IC chip). Thus, the semiconductor chip can be held inside the socket by sandwiching it between the tip portion and the holding plate simply by abutting the holding plate on the through opening into which the semiconductor chip is inserted. Further, in the outer portion, the contact terminal on the flexible substrate is arranged at a position for receiving the contact pin or the probe pin on the tester side. As a result, the matching with respect to the difference in pin pitch between the IC chip and the tester is taken, and the electrical coupling is supported.

Further, the IC chip is inserted through the opening of the through opening on the side opposite to the contact side such as the contact pin, and the lower surface of the IC chip is held by the holding plate.
It can be almost the same as the normal mounting state. Therefore,
It becomes possible to test the bare chip of the IC in a state closer to the mounted state. In addition, basically, a mechanism in which the flexible substrate and the IC chip are mounted on the frame and fixed by the holding plate is sufficient. Therefore, a large number of complicated parts are unnecessary, and a sufficient miniaturization can be achieved.

Further, a flexible substrate having a wiring pattern having a tip as a contact pin for contacting the IC chip is manufactured by plating. Therefore, it is possible to efficiently manufacture an IC chip-side contact pin that can secure a sufficient overdrive and contact pressure even with the demand for a large number of pins and a narrow pitch.
Moreover, since the flexible substrate itself can be used as the supporting plate, the supporting mechanism can be simplified and the thickness can be reduced. As a result, the entire socket becomes smaller and its height can be reduced.

Further, when mass-producing ICs, a large number of semiconductor chip test sockets having the same specifications are required.
Compared to a conventional probe card that requires so-called needle-stand work for each probe pin, a flexible substrate that is relatively mass-produced has high productivity and low cost. Moreover,
Even when assembling a semiconductor chip test socket,
By handling the flexible substrate, the plurality of IC chip side contact pins are handled integrally. Therefore, the productivity of the semiconductor chip test socket as a whole is high.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A chip carrier as an embodiment of a semiconductor chip test socket of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a development view of a chip carrier in which the IC chip 30 is mounted and assembled. FIG. 2A shows a perspective view of the appearance of the chip carrier, and FIG. 2B shows an enlarged cross-sectional view of a portion particularly in contact with the IC chip. Also, in FIG.
The expanded schematic diagram of a flexible substrate is shown.

Here, 20 is a frame main body which is a main part of the frame, 21 is a positioning plate having an opening in the center, 2
2 is a flexible substrate having a plurality of wiring patterns, 2
3 is an upper plate for pressing the flexible substrate 22 from above, 24
Is a clamper for fixing the upper plate 23 to the frame body 20 by a spring force. Also, 25 is an IC inserted from below
A lower plate as a holding plate for holding 30 from below,
It is attached to the frame body 20 with bolts 26.

The flexible substrate 22 has a plurality of wiring patterns (see 14 etc. in FIG. 3), and details of its manufacturing method will be described later. The respective tip portions (see 14d in FIG. 3) of these wiring patterns are exposed without being supported by the substrate, and these are used as IC chip side contact pins. Wiring pattern 1
4 or the like in the middle or at the rear end side (1 in FIG. 3).
4e) is provided, and the contact pin on the tester side is brought into contact therewith, so that electrical coupling between the IC chip 30 and the tester can be supported.

The flexible substrate 22 has a substantially rectangular opening at the center, which is slightly larger than the portion where the contact pads of the IC chip are arranged (see 15b in FIG. 3). Then, the respective tip portions 14d and the like project along the respective sides of the opening 15b. With this opening, the tip portion functions as an IC-side contact pin, and the contact state between the tip of the tip portion 14d and the contact pad of the IC 30 can be monitored. In order that the flexible substrate 22 can be easily deformed without being damaged,
Notches may be provided at the corners of the openings.

Further, the position of the tip end portion is provided corresponding to the arrangement of the contact pads of the IC chip 30, and the contact terminals are arranged at a wide pitch at the rear end side of the wiring pattern connected to the tip pads in correspondence with the arrangement of the tester side contact pins. Is provided. As a result, the fine and narrow pitch pads of the IC chip and the contact pins on the tester side, which are not so fine and have a wide pitch, can be aligned. In addition, IC
If the contact pads of the chip 30 are not provided on all four sides but only on some sides,
It suffices to provide the tip portions on at least two opposite sides. If there are tip portions on the two opposite sides, the IC chip can be stably pressed and held.

A procedure for inserting the IC chip 30 into the chip carrier composed of 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 respective openings aligned. Further, the upper plate 23 is placed on the opening so that the openings are aligned with each other, and the clamper 24 is locked to the frame 20 from above. The clamper 24 is a kind of leaf spring whose central portion is bent.
Press and fix.

All of these parts have openings corresponding to the insertion positions of the IC 30. As a result, the IC 30 that is later inserted from below through this opening can be observed. Further, the upper plate 23 and the clamper 24 are substantially rectangular in plan view, and the contact terminals of the flexible substrate 22 are assembled so as to come to the outside on the long side thereof (reference numeral in FIG. 2A). 22). As a result, the contact terminal can receive the contact pin or the probe pin coming into contact with the external terminal from above.

A portion of the lower surface of the upper plate 23 near the opening is slightly inclined. This causes the tip of the flexible substrate 22 to incline slightly downward. The IC chip 30 is placed upward on the lower plate 25, and in this state, the lower plate 25 is temporarily fixed to the frame 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 to be 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. Since it is smaller than the outer shape of, the IC 30 is lightly held between the tip portion and the lower plate 25.

At this stage, while checking the inner side through the upper opening to check the positional relationship between the tip of the tip and the contact pad of the IC 30, 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 match. When the dicing accuracy of the IC 30 is sufficiently high and the relative position between the chip outer shape and the contact pad is stable, the position of the alignment plate 21 and the flexible substrate 22 are adjusted in advance to fix them. It is good to assemble. In this case, since the opening of the alignment plate 21 corresponds to the outer shape of the IC chip 30, the alignment work performed while monitoring the IC 30 becomes unnecessary, and the insertion work can be performed efficiently.

When the alignment is completed, the lower plate 25 is fixed to the frame body 20 in earnest. As a result, so-called overdrive is applied to the inclined tip portion, and this is surely brought into contact with the contact pad to establish an electrical coupling line (see FIG. 2B). This state is very similar to the state in which the IC chip 30 is mounted on a so-called multichip module or the like. Therefore, it is possible to test the operation state of the IC in the almost mounted state, which also contributes to improvement of reliability of the test result.

When a bump is provided on the contact pad portion of the IC 30 or on the tip of the flexible substrate 22, overdriving is applied within the range of the height of the bump, so that the tip is inclined in advance. You don't have to. The chip carrier assembled in this way is small, 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 shows a schematic sectional view in each step. This is for illustration purposes only
The number of side contact pins is generally several tens to several hundreds, and the pitch is not always constant. In the following, IC
The side contact pin is simply called a pin, the wiring pattern is called a pattern, and the pin 14d and the pattern 14e are collectively called a pin 14. The pin 14 and the film 15 are collectively referred to as a pin film body 22.

In the pin manufacturing process, mainly, the first metal layer forming process, the resist pattern forming process which is the first half of the plating process, and the second metal layer forming the second half of the plating process are performed. It includes an electrolytic plating step of forming, a film adhering step, a peeling step which is the first half of the separating step, and a removing step which is the second half of the separating step. In addition, pin 14
The material is preferably Ni from the viewpoint of strength and toughness. further,
Pd and the like may be included. Further, when importance is attached to conductivity, it is preferable to coat gold 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 the first metal layer is formed on the stainless steel plate 10 as the substrate layer by electrolytic plating. The use of copper as the first metal layer has excellent adherence to the Ni-made pins 14 and the like, and the adhesion to the stainless steel plate 10 is weaker than the adhesion of the film 15 to the Ni-made pins 14 and the like. , Because it is a good conductor. Since copper has better conductivity than stainless steel, electrolytic plating can be performed quickly and uniformly. The stainless steel plate 10 is mirror-finished so that its surface is flat and smooth.

In the resist pattern forming step, the copper layer 11 is used.
A photoresist 12 is coated on the above (see FIG. 4A), and is exposed through a mask 13 (see FIG. 4B). As a result, 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 electroplating step, the void 12a above the copper layer 11 that appears in the portion not covered with the resist mask is used.
Then, Ni is attached and grown by electrolytic plating (see (d) of FIG. 4). After the completion of Ni plating, the resist 12 is removed and the mask is removed (see FIG. 4D). The Ni layer thus formed is used for the pin 14.

In the film deposition step, a polyimide film 15 is coated on the Ni layer (14) to cover the pattern 14e and the like other than the portion provided for the pin 14d. Specifically, the adhesive plastic 15a is sandwiched and thermocompression bonding is performed from above the film 15 with a jig having a flat pressing surface (FIG. 4).
(F)). This makes the plastic side pin 1
Since it is partially deformed in accordance with No. 4, minute irregularities and uneven thickness 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 also has an opening 15b (see FIG. 3). The opening 15b is bonded so as to correspond to the pin 14d. As a result, the pin 14d is supported by the film 15 in a cantilevered state, and the film 15 is used as a substrate that integrally supports the pin 14d and the like.

In the peeling step, the portion consisting of the copper layer 11, the Ni layer (14) and the film 15 is peeled from the stainless plate 10 between the stainless plate 10 and the copper layer 11 to separate it. As described above in the description of the step of forming the first metal layer, the adhesion force to the stainless steel plate 10 is weaker than the adhesion force of the film 15 to the Ni pins 14 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, an Ni layer (14) is formed by using an etching solution having a high selectivity.
The copper layer 11 is removed without damaging. As a result, the portion including the film 15 and the pin 14 is separated from the stainless layer 10 and the copper layer 11. The IC-side contact pin 14 thus manufactured has a substantially rectangular cross section (normally 50 μm × 50 μm). So, when you make a contact by bending it in a cantilever shape,
Greater contact pressure and overdrive capability than those with a triangular or circular cross section. In addition, the bending rigidity in the diagonal direction is large, and it rarely bends at an angle. Therefore, there is no inconvenience even if the pitch is narrowed (about 80 μm).

The side surface 1 that contacts the IC chip
4a, 14b, and 14c have a uniform height corresponding to the flat surface of the stainless steel plate 10.
Therefore, there is no need to perform work for adjusting the height of the pin tip. Further, the side surfaces 14a, 14b, 14c to which tensile stress is applied when making contact with the IC chip have a smooth surface state corresponding to the smooth surface of the stainless plate 10. Therefore, the fatigue strength affected by the smoothness of the surface is increased, and the number of times of repeated use is improved. Then, in the flexible substrate 22 having such pins, the film 15 functions as a support plate that supports the tip end portions 14d of the pins. Therefore, a small chip carrier can be constructed by providing upper and lower plates such as clampers in the height direction.

[0031]

As can be understood from the above description, in the semiconductor chip test socket of the present invention, the tips of the plurality of wiring patterns are exposed without being supported by the substrate and the contact terminals are provided on the rear side. A flexible substrate having a through hole, a frame for fixing the flexible substrate so that the tip portion contacts a pad portion of the semiconductor chip having a through opening, and a holding plate for holding the semiconductor chip in the through hole,
The distance between the tip of the tip of the flexible substrate and the contact surface of the holding plate is the same as or slightly smaller than the thickness of the semiconductor chip. As a result, the bare chip of the IC can be tested in a state close to the mounted state, and a semiconductor chip test socket having a low height, a small size, and high productivity can be realized.

[Brief description of drawings]

FIG. 1 is a development view of a chip carrier as an example of a semiconductor chip test socket having the structure of the present invention.

FIG. 2A is a perspective view of the external appearance of the chip carrier, and FIG. 2B is an enlarged cross-sectional view of a contact portion with an IC chip.

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

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

[Explanation of symbols]

 10 Stainless Steel Plate 11 Copper Layer 12 Photoresist 13 Photomask 14 Pins 15 Film 20 Frame Body 21 Positioning Plate 22 Flexible Board 23 Top Plate 24 Clamper 25 Bottom Plate 26 Bolt 30 IC Chip

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Etch Dun Higgins United States, Arizona, Gilbert, Suite 101, North Tech Boulevard 1478 in Fresh Quest Corporation (72) Inventor Pete Normington United States, Arizona, Gilbert, Sweet 101, Nostech Boulevard 1478 in Fresh Quest Corporation (56) Reference JP 62-276861 (JP, A) Actual development Sho 64-33745 (JP, U)

Claims (3)

[Claims] 1. A flexible substrate having a plurality of wiring patterns, each of which has its tip end exposed without being supported by the substrate and having a contact terminal in the middle or at the rear end side thereof, and an integrated circuit formed on the flexible substrate. Has a through hole for receiving 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 each of the tip portions contacts each pad portion of the semiconductor chip in the through hole. As described above, a frame for fixing the flexible substrate, and a semiconductor chip inserted through the opening of the through opening on the side opposite to the side where the contact pin or the probe pin comes into contact are brought into contact with the lower surface of the semiconductor chip and the through hole is formed. A holding plate for holding the opening in the opening; and a semiconductor chip of the holding plate from the tip of the tip portion. Semiconductor chip test socket distance to Sawamen is characterized in that the thickness of the semiconductor chip and the same or it slightly smaller than the. 2. The through-opening is a rectangular shape which is larger than this and corresponds to the outer shape of the semiconductor chip, and the flexible substrate is a substantially rectangular opening which is larger than this corresponding to the arrangement of the pads of the semiconductor chip. Alternatively, the positioning has a notch, the pitch of each contact terminal is larger than the pitch of each tip, and an opening corresponding to the outer shape of the semiconductor chip is provided between the tip and the holding plate. The semiconductor chip test socket according to claim 1, further comprising a plate. 3. The semiconductor chip test socket according to claim 2, wherein the tip portion is inclined toward the side where the semiconductor chip is inserted.