JP2023176962A - Anisotropic conductive sheet and method for manufacturing anisotropic conductive sheet - Google Patents

Abstract

[Problem] An anisotropic structure that allows stable repeated inspections while suppressing the force applied to an object to be inspected such as a semiconductor device by dividing the penetration part into a configuration consisting of multiple through holes. The purpose of the present invention is to provide a conductive sheet with high conductivity.
[Solution] An anisotropic conductive sheet 1 includes a sheet-like insulating layer 2 made of a resin material, a plurality of through parts 3 penetrating the insulating layer 2 in the thickness direction, and a metal thin film formed in each of the through parts 3. The through hole 3 has a through electrode 31 (or a through electrode 32) consisting of a through electrode 31 (or a through electrode 32), and the through hole 3 is formed independently in the circumferential direction by partitioning a plurality of through holes 2c with a partition 2d. ) is a configuration arranged in the through hole 2c.
[Selection diagram] Figure 1

Description

The present invention relates to an anisotropic conductive sheet and a method for manufacturing an anisotropic conductive sheet for repeatedly testing objects to be inspected such as semiconductor devices.

Conventionally, a method for manufacturing an electrical connector has been proposed in which a through hole is formed in a base sheet made of a resin material to form a hollow structure, and a through electrode made of a metal thin film is formed in the through hole (Patent Document 1: Japanese Patent Application Laid-Open No. 2020-027859, Patent Document 2: International Publication No. 2018/212277).

Japanese Patent Application Publication No. 2020-027859 International Publication No. 2018/212277

Semiconductor devices are becoming increasingly integrated, and anisotropic conductive sheets having narrower pitch electrodes are required to accommodate these semiconductor devices. However, since the hollow structure reduces the volume of the through electrode and increases the resistance value, there is a quality problem in that the influence of the resistance value when testing electrical characteristics becomes large.

The present invention has been made in view of the above-mentioned circumstances, and by dividing the penetration part into a configuration consisting of a plurality of through holes, it is possible to stably repeat inspections while suppressing the force applied to the object to be inspected, such as a semiconductor device. An object of the present invention is to provide an anisotropic conductive sheet having a configuration that allows the following.

In one embodiment, the above problem is solved by a solution as disclosed below.

An anisotropic conductive sheet according to the present invention includes a sheet-shaped insulating layer made of a resin material, a plurality of through parts penetrating the insulating layer in the thickness direction, and a through electrode made of a metal thin film formed in the through parts. The through-hole is characterized in that the through-hole is formed independently in the circumferential direction by partitioning a plurality of through-holes into partitions, and the through-hole electrode is disposed in the through-hole.

According to this configuration, it is possible to suppress the force applied to the object to be inspected, and by reducing the resistance value of the through electrode, it is possible to repeatedly perform inspections stably.

The number of through holes in each of the through parts is two or more. It is preferable that the number of the through holes in each of the through parts is 2 or more and 9 or less. Thereby, expansion and contraction of the insulating layer can be maintained and a necessary resistance value can be ensured. It is more preferable that the number of the through holes in each of the through parts is six or less. This makes it easy to secure the necessary conductor area.

As an example, the shape of the penetrating portion is set to a semicircular shape, a fan shape, a triangular shape, a quadrangular shape, a hexagonal shape, a polygonal shape, a circular shape, etc. in plan view. As an example, the shape of the through hole is set to a semicircular shape, a fan shape, a triangular shape, a quadrangular shape, a hexagonal shape, a polygonal shape, a circular shape, etc. in plan view. Therefore, the shape of the through electrode is set to a semicircular shape, a fan shape, a triangular shape, a quadrangular shape, a hexagonal shape, a polygonal shape, a circular shape, etc. in plan view.

When compared with a hollow structure in which the penetrating portion is circular in plan view, by dividing the circular shape into two or more, the shape of the penetrating electrode becomes semicircular or fan-shaped. Therefore, when comparing the area with a simple perfect circle, a semicircular shape with two divisions is about 1.6 times, a fan shape with three divisions is about 1.9 times, and a fan shape with four divisions is about 2.2 times. So, for a fan shape with 5 divisions, it will be about 2.5 times, for a fan shape of 6 divisions, it will be about 2.8 times, for a fan shape of 7 divisions, it will be about 3.1 times, and for a sector shape of 8 divisions, it will be about 3. It becomes 3 times as much, and becomes about 3.6 times in the fan shape of 9 divisions, and by increasing the number of divisions of the penetration part, it is possible to expand the area in contact with the external electrode of the object to be inspected. As a result, while suppressing the force applied to the test object due to the hollow structure, it is possible to reduce the resistance value and perform repeated tests stably.

When compared with a hollow structure in which the penetrating portion has a rectangular shape in plan view, the shape of the through electrode becomes triangular by dividing the rectangular shape into two or more. Therefore, when comparing the area with a simple square, a triangle divided into two is approximately 1.45 times larger, a triangle divided into three is approximately 1.7 times larger, a triangle divided into four is approximately 1.95 times larger, and a triangle divided into four is approximately 1.95 times larger. For a triangular shape divided into three parts, it becomes about 2.2 times, for a triangular shape divided into six parts, it becomes about 2.45 times, for a triangular shape divided into seven parts, it becomes about 2.7 times, and for a triangular shape divided into eight parts, it becomes about 2.95 times. , is approximately 3.2 times larger in a triangular shape divided into nine parts, and by increasing the number of divisions of the penetration part, the area in contact with the external electrode of the object to be inspected can be expanded. As a result, while suppressing the force applied to the test object due to the hollow structure, it is possible to reduce the resistance value and perform repeated tests stably.

The thickness of the insulating layer is preferably 0.05 mm or more. Thereby, the pressing force when inspecting the object to be inspected can be alleviated. It is preferable that the thickness of the insulating layer is 2.00 mm or less. This makes it possible to suppress fluctuations in the resistance value when the test object is made conductive. The thickness of the insulating layer is more preferably 0.1 mm or more and 0.5 mm or less. As an example, the resin material is made of a rubber elastic body. This makes it possible to create a structure that is highly stretchable and has excellent elastic restoring force. As an example, the diameter of the penetrating portion is set to 0.001 mm or more and 0.040 mm or less.

As an example, one end surface and the other end surface of the through electrode in the thickness direction each protrude by 0.8 times or less the thickness of the insulating layer. With this configuration, conduction with the through electrode can be more ensured when inspecting an object to be inspected, and contact resistance can be reduced.

The method for producing an anisotropic conductive sheet according to the present invention includes a sheet-like insulating layer made of a resin material, a plurality of penetration parts penetrating the insulating layer in the thickness direction, and a metal thin film formed in the penetration parts. A method for manufacturing an anisotropic conductive sheet having a through electrode, wherein a plurality of through holes are divided into partitions and formed independently in the circumferential direction of the through hole, and the through electrode is disposed in the through hole. It is characterized by

According to this configuration, it is possible to suppress the force applied to the object to be inspected, and by reducing the resistance value of the through electrode, it is possible to repeatedly perform inspections stably. As an example, the through electrode is formed by metal plating.

According to the present invention, by dividing the penetration part into a configuration consisting of a plurality of through holes, the configuration allows stable repeated inspection while suppressing the force applied to the object to be inspected such as a semiconductor device. Anisotropic conductive sheets can be realized.

FIG. 1 is a perspective view schematically showing a first example of an anisotropic conductive sheet according to an embodiment of the present invention. FIG. 2A is a plan view schematically showing essential parts of the anisotropic conductive sheet of the first example, FIG. 2B is a sectional view taken along line BB in FIG. 2A, and FIG. 2C is a bottom view in FIG. 2A. . FIG. 3A is a plan view schematically showing the main parts of the anisotropic conductive sheet of the second example, FIG. 3B is a sectional view taken along the line BB in FIG. 3A, and FIG. 3C is a bottom view in FIG. 3A. . FIG. 4 is a flow diagram showing a manufacturing procedure of an anisotropic conductive sheet according to an embodiment of the present invention. FIG. 5A is a plan view schematically showing a main part of a modification of the first example, FIG. 5B is a plan view schematically showing a main part of a modification of the first example, and FIG. 5C is a plan view schematically showing a main part of a modification of the first example. It is a top view which shows typically the principal part of the modification. FIG. 6 is a side view schematically showing the positional relationship between the anisotropic conductive sheet and the semiconductor device according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The anisotropic conductive sheet 1 according to this embodiment is applied to testing the electrical characteristics of objects to be tested such as semiconductor devices and semiconductor elements. The anisotropic conductive sheet 1 includes a sheet-like insulating layer 2 made of a resin material, a plurality of through parts 3 that penetrate the insulating layer 2 in the thickness direction, and a through electrode made of a metal thin film formed in each of the through parts 3. 31 (or through electrode 32), the through hole 3 has a plurality of through holes 2c separated by partitions 2d and formed independently in the circumferential direction, and the through hole 31 (or through electrode 32) has a through hole. 2c. Here, in order to make it easier to explain the positional relationship of each part of the anisotropic conductive sheet 1, the directions are indicated by X, Y, and Z arrows in the figure. The anisotropic conductive sheet 1 can be used in any orientation. In addition, in all the figures for explaining the embodiment, members having the same function are given the same reference numerals, and repeated explanation thereof may be omitted.

The resin material constituting the insulating layer 2 is made of a rubber elastic body. The resin materials include silicone rubber, fluorine rubber, urethane rubber, acrylic rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, ethylene-vinyl acetate rubber, chloroprene rubber, Chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, thiol rubber, natural rubber, nitrile rubber, and other known rubber elastic bodies are applicable. In particular, silicone rubber, fluororubber, urethane rubber, and acrylic rubber are preferred because they have excellent chemical resistance.

As an example, the thickness of the insulating layer 2 is 2.00 mm or less, the compressive elastic modulus of the insulating layer 2 in the thickness direction is set to 5 N/mm ² or less, and the volume resistivity of the insulating layer 2 is more than 10^12 Ω·cm. is set to When inspecting the test object 40 such as a semiconductor device or a semiconductor element, the load applied to the test object 40 is set to 10 gf or less.

The through electrode 31 (or the through electrode 32) is formed of a highly conductive metal conductor. As the highly conductive metal conductor, gold, platinum, copper, copper alloy, nickel, nickel alloy, and other known noble metals can be suitably employed. For example, 5 to 50 through holes 2c in which the through electrodes 31 (or through electrodes 32) are formed are arranged in the X direction at a pitch P1, and 5 to 50 through holes 2c are arranged in the Y direction at a pitch P1. ing. The through holes 2c are arranged in a matrix, and the pitch P1 is, for example, 0.005 mm or more and 0.05 mm or less. The shape of the through hole 2c is set to a semicircular shape, a fan shape, a triangular shape, a quadrangular shape, a hexagonal shape, a polygonal shape, a circular shape, etc. in plan view. As an example, the diameter of the through hole 2c is set to 0.005 mm or more and 0.025 mm or less. Here, the shape and arrangement of the penetration part 3 are such that two or more of the plurality of penetration electrodes 31 (or penetration electrodes 32) can come into contact with the external electrode 41 of the test object 40 such as a semiconductor device or a semiconductor element. Any configuration may be used, and the configuration is not limited to the above configuration. Note that the external electrode 41 is not limited to a metal terminal, but may be a solder ball.

Next, the first example of the anisotropic conductive sheet 1A will be described below.

[First example]
FIG. 2A is a plan view schematically showing a main part of the anisotropic conductive sheet 1A of the first example, FIG. 2B is a sectional view taken along the line BB in FIG. 2A, and FIG. 2C is a bottom view in FIG. 2A. be. The anisotropic conductive sheet 1A includes a sheet-like insulating layer 2 made of a resin material, a plurality of circular penetration parts 3 penetrating the insulating layer 2 in the thickness direction, and a metal thin film formed in each of the penetration parts 3. The penetrating part 3 has a total of three fan-shaped through holes 2c divided by partition parts 2d formed on the inner wall of the insulating layer 2, and formed independently at equal intervals in the circumferential direction. , the through electrodes 31 are arranged in each of the through holes 2c. The through electrode 31 is arranged at a position rotationally symmetrical with respect to the center line P3 of the through part 3 in the thickness direction. Each through electrode 31 has a fan shape in plan view. Here, the number of through electrodes 31 can be increased or decreased within the range of 2 to 9. FIG. 5A is a plan view schematically showing a main part of a modification of the first example, and in this example, a total of two semicircular through electrodes 31 are arranged to form the through part 3. FIG. 5B is a plan view schematically showing a main part of a modification of the first example, and in this example, a total of four fan-shaped through electrodes 31 are arranged to form the through part 3.

In the example of FIG. 2B, the size T2 of the through electrode 31 in the thickness direction is set to a larger value than the size T2 of the insulating layer 2 in the thickness direction. One end surface and the other end surface of the through electrode 31 in the thickness direction each protrude by 0.8 times or less the thickness of the insulating layer 2.

FIG. 6 is a side view schematically showing the positional relationship between the anisotropic conductive sheet 1A and an object to be inspected 40 such as a semiconductor device, and is a partially enlarged view. As an example, the test object 40 is a chip-type IC, and has a plurality of external electrodes 41. Here, the pitch P1 of the penetrating portions 3 is set to a smaller value than the pitch P2 of the external electrodes 41. As an example, the pitch P1 is set to 1/3 or less of the pitch P2. As a result, a configuration can be created in which two or more of the plurality of through electrodes 31 (or through electrodes 32) in the through part 3 can come into contact with the external electrode 41 of the object to be inspected 40 such as a semiconductor device or a semiconductor element. A multi-contact structure is formed, and the degree of freedom in alignment between the through electrode 31 (or the through electrode 32) and the external electrode 41 is increased.

According to this embodiment, the anisotropic conductive sheet 1A can be configured to easily accommodate variations in the pitch, size, etc. of the external electrodes 41 in the object 40 to be inspected. The force applied to the object 40 to be inspected, such as a semiconductor device or a semiconductor element, can be suppressed and evenly distributed. Furthermore, the resistance value of the through electrode 31 can be reduced. The partitions also provide a more robust structure. Therefore, inspections can be performed repeatedly and stably.

FIG. 4 is a flow diagram showing the manufacturing procedure of the anisotropic conductive sheet 1 according to this embodiment. Next, the manufacturing method of this embodiment will be described below along with a flowchart.

A base is prepared in which circular needle-shaped core materials made of metal are arranged at a pitch P1. The core material has slits formed at equal intervals in the outer circumferential direction, and is divided into sections by the slits. In step S1, the core material is plated with a metal made of gold, platinum, or copper to form a plurality of through electrodes 31 on the outer periphery of the divided core material.

Following step S1, in step S2, for example, liquid silicone resin, fluororesin, or urethane resin is poured into the mold in which the base is placed, and the resin is cured to form an insulating layer including the partitioned portion 2d. form 2.

Following step S2, in step S3, the core material is melted with an etchant to remove unnecessary areas. For example, when the core material is iron or aluminum and the metal plating is gold or platinum, hydrogen fluoride (HF) can be used as the etchant. The etchant is discharged from the nozzle in the form of an etchant dissolved in water or an aqueous solution at a desired etchant concentration. After removing the unnecessary area, the etching solution is washed away with water or the like. In this way, the anisotropic conductive sheet 1 is manufactured.

According to this configuration, the plurality of through electrodes 31 (or through electrodes 32) are formed at equal intervals in the circumferential direction of the through part 3, so that the force applied to the object to be inspected 40 such as a semiconductor device is suppressed and evenly distributed. be able to. Furthermore, the resistance value of the through electrode 31 (or the through electrode 32) can be reduced. Further, the partition portion 2d provides a more robust structure, and the adhesion between the through electrode 31 (or the through electrode 32) and the insulating layer 2 can be further improved. Furthermore, nanometer-sized penetration portions 3 can be manufactured with good reproducibility.

Next, a second example of the anisotropic conductive sheet 1B will be described below.

[Second example]
3A is a plan view schematically showing the main parts of the anisotropic conductive sheet 1B of the second example, FIG. 3B is a sectional view taken along the line BB in FIG. 3A, and FIG. 3C is a bottom view in FIG. 3A. be. The anisotropic conductive sheet 1B includes a sheet-shaped insulating layer 2 made of a resin material, a plurality of square-shaped penetration parts 3 penetrating the insulating layer 2 in the thickness direction, and a metal thin film formed in each of the penetration parts 3. The penetrating part 3 has a total of three triangular through holes 2c divided by partition parts 2d formed on the inner wall of the insulating layer 2, and formed independently at equal intervals in the circumferential direction. , the through electrodes 31 are arranged in each of the through holes 2c. The through electrode 31 is arranged at a position rotationally symmetrical with respect to the center line P3 of the through part 3 in the thickness direction. Each through electrode 32 has a triangular shape in plan view. Here, the number of through electrodes 32 can be increased or decreased within the range of 2 to 9. FIG. 5C is a plan view schematically showing a main part of a modification of the second example, and in this example, a total of six triangular through electrodes 32 are arranged to form a hexagonal through hole 3. .

In the example of FIG. 3B, the size T2 of the through electrode 32 in the thickness direction is set to a larger value than the size T2 of the insulating layer 2 in the thickness direction. One end surface and the other end surface of the through electrode 32 in the thickness direction each protrude by 0.8 times or less the thickness of the insulating layer 2.

The configuration of the second example is to prepare a base in which rectangular needle-shaped core materials made of metal are arranged at a pitch P1, and to form slits in the core materials at equal intervals in the outer circumferential direction. can be manufactured in the same way. The penetrating portion 3 is not limited to a square shape or a hexagonal shape, but may also be a pentagonal shape, an octagonal shape, or the like.

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the scope of the present invention.

1, 1A, 1B, 1C Anisotropic conductive sheet 2 Insulating layer, 2c Through hole, 2d Division section 3 Through section 31 Through electrode 32 Through electrode 40 Test object (semiconductor device)
41 External electrode

Claims (5)

It has a sheet-shaped insulating layer made of a resin material, a plurality of through parts penetrating the insulating layer in the thickness direction, and a through electrode made of a metal thin film formed in the through part, and the through part has a plurality of through parts. An anisotropic conductive sheet characterized in that the through holes are separated by partitions and formed independently in the circumferential direction, and the through electrodes are disposed in the through holes. The anisotropic conductive sheet according to claim 1, wherein the number of the through holes in each of the through parts is 2 or more and 9 or less. The anisotropic conductive sheet according to claim 1 or 2, wherein the thickness of the insulating layer is 0.05 to 2.00 mm. 4. The anisotropic conductive sheet according to claim 3, wherein one end surface and the other end surface of the through electrode in the thickness direction each protrude by 0.8 times or less the thickness of the insulating layer. A method for producing an anisotropic conductive sheet having a sheet-shaped insulating layer made of a resin material, a plurality of through parts penetrating the insulating layer in the thickness direction, and a through electrode made of a metal thin film formed in the through parts. A method for manufacturing an anisotropic conductive sheet, characterized in that a plurality of through holes are divided by partitions and formed independently in the circumferential direction of the through holes, and the through electrodes are arranged in the through holes. .

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