TWM629691U - Conductive adhesive for chip testing - Google Patents

Abstract

The present invention relates to a conductive adhesive used for wafer testing, including a support frame for supporting the conductive glue, conductive pillars distributed on the support frame according to the positions of the pins of the chip, elastic springs filled between the conductive pillars An insulating glue and a flexible circuit board laid on the surface of the conductive post and the elastic insulating glue; wherein, a conductive metal layer corresponding to the position of the conductive post is arranged on the flexible circuit board. In this creation, the probe is replaced by the conductive glue, and the elasticity of the conductive glue itself is used to slow down the impact force that collides with the chip pins during the test, thereby prolonging the service life; The flexible circuit board is provided with a conductive metal layer corresponding to the position of the conductive column, so as to avoid the direct contact of the chip pins with the conductive glue during testing, further improving the service life of the conductive glue and reducing the test cost. At the same time, the conductive adhesive also has the advantage of small loss of high-frequency signals.

Description

Conductive Adhesives for Wafer Testing

The present invention relates to the technical field of wafer testing equipment, in particular to a conductive adhesive for wafer testing.

At present, after the integrated circuit chip is packaged, the function of the chip needs to be tested to screen qualified products. The tester puts the chip to be tested into the test equipment equipped with test probes, and tests one end of each test probe corresponding to the chip. When testing the pins, the probes intermittently touch the pins of the chip at high frequency to cause wear. However, for some chips that require high-frequency test signals (such as test chips), the test chips need to be used to pass the high frequency. This kind of high-frequency test probe is expensive, which makes the test cost high; on the other hand, when the test probe is used for testing, there is also a problem of large loss of high-frequency signal.

The technical problem to be solved by this creation is to provide a conductive adhesive and a testing device for the above-mentioned defects in the prior art.

The technical solution adopted by this creation to solve the technical problem is to construct a conductive adhesive for wafer testing, which includes elastic conductive pillars distributed corresponding to the test points of the wafer, elastic insulating adhesive filled between the conductive pillars, and a supporting arrangement. A support frame around the elastic insulating glue, and a flexible circuit board disposed on the surface of the conductive post adjacent to the test point of the chip; wherein the conductive post penetrates the elastic The flexible circuit board is provided with a conductive metal layer corresponding to the conductive column and conductively connected to the test point of the chip and the conductive column.

Preferably, the conductive pillars comprise conductive metal particles and silica gel mixed together to form conductive paths.

Preferably, the flexible circuit board includes a flexible double-sided circuit board; the flexible double-sided circuit board includes an insulating base material, a conductive metal layer is provided on the front and back of the insulating base material, and a front side is opened on the base material. or, the flexible circuit board includes a flexible single-sided circuit board, and the flexible single-sided circuit board includes an insulating base material, a conductive through slot provided on the insulating base material, and a conductive metal layer embedded in the conductive through groove and conductively connected to the front and back sides of the insulating substrate.

Preferably, the conductive metal layer is a complete surface, or, the surface of the conductive metal layer is provided with cracks for facilitating elastic deformation under pressure.

Preferably, the thickness of the conductive metal layer is between 0.01 and 0.1 mm.

Preferably, the surface of the conductive metal layer is gold-plated, platinum or palladium.

Preferably, the shape of the conductive metal layer is a circle, an ellipse or a rectangle.

Preferably, the supporting frame is provided with a positioning hole, through which the conductive posts on the conductive adhesive are in a one-to-one correspondence with the pin positions of the chip.

Preferably, an adhesive for increasing the bonding force between the conductive metal layer and the elastic insulating glue is provided between the flexible circuit board and the elastic insulating glue.

The conductive glue implemented in this creation has the following beneficial effects: the conductive glue replaces the probe, and the elasticity of the conductive glue itself is used to slow down the impact force when it touches the chip pins during testing, thereby prolonging the service life; A layer of flexible circuit board is bonded to the surface of the conductive column of the conductive adhesive, and a conductive metal layer corresponding to the position of the conductive column is arranged on the flexible circuit board, so as to avoid the lead of the wafer during testing. The feet directly touch the conductive adhesive, which further improves the service life of the conductive adhesive and reduces the test cost. At the same time, the conductive adhesive also has the advantage of small loss of high-frequency signals.

1: Conductive column

2: Elastic insulating glue

3: Support frame

4: Positioning hole

5: Conductive metal particles

6: Conductive metal layer

61: Crucifix

62: Trident Crack

63: Five-pronged crack

7: Flexible circuit board

9: Protect the ring

This creation will be further described below in conjunction with the accompanying drawings and embodiments. Among the accompanying drawings: Figure 1 is a top view of the three-dimensional structure of the conductive adhesive of this creation; Figure 2 is a front view of the three-dimensional structure of the conductive glue of this creation; Schematic diagram of the structure of the conductive column created by the creation; Figure 4 is the schematic diagram of the structure of the conductive metal layer and the flexible circuit board of the creation; Figure 5 is the schematic diagram of the structure of the conductive metal layer of the creation; Figure 6 is the conductive metal layer of the creation. Schematic diagram of the crack structure; Figure 7 is a schematic diagram of the crack-free structure of the conductive metal layer of this creation; Figure 8 is a schematic structural diagram of the protection ring of this creation.

The technical solutions in the creative embodiment will be clearly and completely described below with reference to the accompanying drawings in the creative embodiment. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments in this creation, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of this creation. It should be understood that the accompanying drawings are only provided for reference and illustration, and are not used to limit the present invention. The connections shown in the drawings are only for the convenience of clear description, and do not limit the connection manner.

As shown in FIG. 1 and FIG. 2, a conductive adhesive for wafer testing provided by the present invention is characterized in that it includes elastic conductive pillars 1 distributed corresponding to the test points of the wafer, filled in the conductive adhesive. The elastic insulating glue 2 between the electrical posts 1, the supporting frame 3 arranged around the elastic insulating glue 2, and the flexible circuit board 7 arranged on the surface of the conductive post 1 adjacent to the test point of the chip; wherein, The conductive post 1 penetrates through the elastic insulating glue 2 , and a conductive metal layer 6 corresponding to the conductive post 1 and conductively connected to the chip and the conductive post 1 is provided on the flexible circuit board.

Further, positioning holes 4 are provided around the support frame 3 , through which the conductive posts 1 on the conductive glue are in a one-to-one correspondence with the pin positions of the wafer.

Further, as shown in FIG. 3 , the conductive pillars include conductive metal particles and silica gel which are mixed together to form conductive paths. Among them, the conductive metal particles 5 in the conductive column 1 provide an electrical signal path, and the elastic properties of the silicone rubber slow down the impact force when it touches the chip pins during testing, thereby prolonging the service life. The conductive silicone rubber has a cost relative to the test probe. It has the advantages of small signal loss when passing high-frequency signals.

In some embodiments, as shown in FIG. 4, the flexible circuit board 7 includes a flexible double-sided circuit board; the flexible double-sided circuit board includes an insulating base material, and conductive metal layers 6, And the conductive through holes that connect the conductive metal layers 6 on the front and the back are provided on the base material; or, the flexible circuit board 7 includes a flexible single-sided circuit board, and the flexible single-sided circuit board includes an insulating The conductive through groove provided on the conductive through groove, and the conductive metal layer 6 embedded in the conductive through groove and conductively connected to the front and back sides of the insulating base material.

Further, as shown in FIG. 5 to FIG. 7 , the surface of the conductive metal layer 6 is provided with cracks for facilitating elastic deformation under pressure; of course, the conductive metal layer 6 may be a complete surface in some embodiments. Wherein, the cracks can be carved out by etching or laser engraving. Preferably, the cracks can be cross-shaped cracks 61, trident-shaped cracks 62, penta-shaped cracks 63, etc. Of course, they can also be cracks of other shapes. Here No specific restrictions are made. In addition, the conductive metal layer may not have cracks, but it is necessary to ensure that the thickness of the conductive metal layer 6 is thin enough, generally within 100um, so that the The conductive metal layer 6 itself is sufficiently soft, and the elasticity of the entire conductive adhesive will not be affected by the hardness of the conductive metal layer 6 .

Further, the crack extends from the conductive metal layer 6 to the protection ring 9 , and is located in or beyond the area where the conductive metal layer 6 is located. As shown in FIG. 8 , the crack exceeds the area where the conductive metal layer 6 is located; a protective ring 9 is also provided around the conductive metal layer. When the crack exceeds the boundary of the conductive metal layer, the protective ring 9 can prevent the crack from further cracking, increasing the The firmness of cracks. Preferably, the protection ring 9 may be a copper ring or other alloy rings, which are not specifically limited here.

Further, the thickness of the conductive metal layer 6 is between 0.01 and 0.1 mm.

Further, the surface of the conductive metal layer 6 is platinum or palladium. By plating the surface of the conductive metal layer with a wear-resistant alloy metal, on the one hand, the use time of the conductive metal layer can be increased, and on the other hand, it can also prevent the conductive column from being damaged. Conductive metal particles oxidize.

Further, the shape of the conductive metal layer 6 is a circle, an ellipse or a rectangle. Of course, the conductive metal layer can be set according to the shape of the test pin, which is not specifically limited here.

In some embodiments, an adhesive for increasing the bonding force between the conductive metal layer 6 and the elastic insulating adhesive 2 is provided between the flexible circuit board 7 and the elastic insulating adhesive 2 .

The present invention also provides a testing device including any one of the above conductive adhesives.

In specific use, the test conductive adhesive is customized according to the pin position of the chip to be tested. Through the positioning holes on the support frame, the conductive posts on the conductive adhesive are in one-to-one correspondence with each pin position of the chip, and the conductive adhesive The other side is connected to the signal output circuit board and the test equipment, so that the signal of the test equipment is connected to the wafer to be tested through the test device for testing.

It can be understood that the above embodiments only express the preferred embodiments of the present creation, and the description thereof is more specific and detailed, but it should not be construed as a limitation on the scope of the invention patent; Generally speaking, on the premise of not departing from the creative concept, the above technical features can be freely combined, and some deformations and improvements can also be made. These all belong to the protection scope of this creation; therefore, all equivalent transformations and modifications made to the patent scope of this creation shall fall within the scope of the patent scope of this creation.

1: Conductive column

2: Elastic insulating glue

3: Support frame

4: Positioning hole

Claims (10)

A conductive glue for chip testing, comprising an elastic conductive column corresponding to a test point of a chip, an elastic insulating glue filled between the elastic conductive columns, and a supporting frame arranged around the elastic insulating glue , and a flexible circuit board arranged on the surface of the elastic conductive post and the test point of the chip adjacent to the side; wherein, the elastic conductive post penetrates the elastic insulating glue, and the flexible circuit board is provided with the elastic The conductive pillars correspond to a conductive metal layer of the elastic conductive pillars and are conductively connected to the test points of the chip and the elastic conductive pillars. The conductive adhesive for wafer testing according to claim 1, wherein the elastic conductive pillars comprise conductive metal particles and silicone adhesives mixed together to form conductive paths. The conductive adhesive for wafer testing according to claim 1, wherein the flexible circuit board includes a flexible double-sided circuit board; the flexible double-sided circuit board includes an insulating substrate, and the front and back sides of the insulating substrate are The conductive metal layer is provided, and a conductive through hole is formed on the insulating base material to electrically connect the conductive metal layers on the front and back sides; or the flexible circuit board includes a flexible single-sided circuit board, and the flexible single-sided circuit The board includes an insulating base material, a conductive through groove set on the insulating base material, and the conductive metal layer embedded in the conductive through groove and conductively connected to the front and back sides of the insulating base material. The conductive adhesive for wafer testing according to claim 3, wherein the conductive metal layer is a complete surface, or a crack is formed on the surface of the conductive metal layer to facilitate elastic deformation under pressure. The conductive adhesive for wafer testing according to item 4 of the patent application scope, wherein the thickness of the conductive metal layer is between 0.01 and 0.1 mm. The conductive adhesive for wafer testing according to claim 5, wherein the surface of the conductive metal layer is plated with gold, platinum or palladium. The conductive adhesive for wafer testing according to claim 6, wherein the shape of the conductive metal layer is a circle, an ellipse or a rectangle. The conductive adhesive for wafer testing according to item 6 of the scope of the patent application, wherein the periphery of the conductive metal layer is further provided with a protective ring for increasing the firmness of cracks; the crack extends from the conductive metal layer to the protective ring The direction extends in or beyond the area where the conductive metal layer is located. The conductive adhesive for chip testing according to claim 1, wherein the support frame is provided with a positioning hole around it, through which the elastic conductive posts on the conductive adhesive and the pin positions of the chip are located one by one. correspond. The conductive adhesive for chip testing according to claim 1, wherein an adhesive bond for increasing the bonding force between the conductive metal layer and the elastic insulating adhesive is provided between the flexible circuit board and the elastic insulating adhesive agent.

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