Anisotropic conductive sheet, electrical inspection device, and electrical inspection method

Abstract

To provide an anisotropic conductive sheet in which the conductive layer is less likely to be broken even when it is repeatedly subjected to a pressing load and whose electrical resistance value is less likely to increase.SOLUTION: An anisotropic conductive sheet includes an insulating layer having a first surface that is located on one side in a thickness direction and on which an inspection target object is placed, a second surface located on the other side, and a plurality of through-holes penetrating from the first surface to the second surface, and a plurality of conductive portions arranged on the respective inner wall surfaces of the plurality of through-holes. The insulating layer includes a first elastomer layer and a second elastomer layer arranged to be closer to the second surface side than the first elastomer layer, and the hardness of the second elastomer layer is lower than the hardness of the first elastomer layer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an anisotropic conductive sheet, an electrical inspection device, and an electrical inspection method. [Background technology]

[0002] Semiconductor devices such as printed wiring boards mounted on electronic products are usually subjected to electrical testing. Electrical testing is usually performed by electrically connecting a board having electrodes of an electrical testing device to terminals of an object to be tested such as a semiconductor device, and reading the current when a predetermined voltage is applied between the terminals of the object to be tested. In order to ensure the electrical connection between the electrodes of the board of the electrical testing device and the terminals of the object to be tested, an anisotropic conductive sheet is placed between the board of the electrical testing device and the object to be tested.

[0003] An anisotropic conductive sheet is a sheet that is conductive in the thickness direction and insulating in the surface direction, and is used as a probe (contact) in electrical testing. Such an anisotropic conductive sheet is used by applying a pressing load to ensure electrical connection between the substrate of an electrical testing device and the object to be tested.

[0004] Various anisotropic conductive sheets are known. Figures 1A and 1B are schematic diagrams of the anisotropic conductive sheet of Patent Document 1. Patent Document 1 discloses an anisotropic conductive sheet 10 having an insulating layer 11 having a plurality of through holes 12 and a plurality of conductive layers 13 arranged corresponding to the plurality of through holes 12 (see Figures 1A and 1B). The insulating layer 11 includes an elastomer layer 11A (see Figure 1B). In this way, the insulating layer 11 includes the elastomer layer 11A, so that it can be elastically deformed by receiving a pressing load. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2021 / 100824 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, when performing electrical testing, in order to ensure an electrical connection between the electrodes of the board of the electrical testing device and the terminals of the test object, a pressing load is applied to the test object placed on the anisotropic conductive sheet. However, in the anisotropic conductive sheet as described above, the load tends to concentrate on the surface portion to which the pressing load is applied, and the surface portion is more likely to be distorted than other portions. This causes a problem that the conductive layer on the surface portion of the anisotropic conductive sheet is likely to crack or break, and the electrical resistance value is likely to increase.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide an anisotropic conductive sheet, an electrical inspection device, and an electrical inspection method in which the conductive layer is less likely to break and the electrical resistance value is less likely to increase even when repeatedly subjected to indentation loads. [Means for solving the problem]

[0008] The above problem can be solved by the following configuration.

[0009] [1] An anisotropic conductive sheet comprising: an insulating layer having a first surface on one side in a thickness direction, a second surface on the other side, and a plurality of through holes penetrating from the first surface to the second surface; a plurality of conductive portions arranged on inner wall surfaces of each of the plurality of through holes; a plurality of first conductive layers arranged on the first surface of the insulating layer and connected to one or more of the conductive portions; and a plurality of second conductive layers arranged on the second surface of the insulating layer and connected to one or more of the conductive portions, wherein the insulating layer comprises a first elastomer layer and a second elastomer layer arranged closer to the second surface than the first elastomer layer, and the hardness of the second elastomer layer is lower than the hardness of the first elastomer layer. [2] The anisotropic conductive sheet according to [1] or [2], further comprising a third elastomer layer arranged on the opposite side of the first elastomer layer with the second elastomer layer therebetween, wherein the hardness of the second elastomer layer is lower than the hardness of the third elastomer layer. [3] The anisotropic conductive sheet according to [1] or [2], wherein an object to be inspected is placed on the first surface side. [4] The anisotropic conductive sheet according to any one of [1] to [3], wherein the first elastomer layer has a hardness of 50 or more. [5] The anisotropic conductive sheet according to any one of [1] to [4], wherein the second elastomer layer has a hardness of 10 or more and less than 50. [6] The anisotropic conductive sheet according to any one of [1] to [5], wherein the difference in hardness between the first elastomer layer and the second elastomer layer is 10 or more. [7] The anisotropic conductive sheet according to any one of [1] to [6], wherein the second elastomer layer has a thickness greater than a thickness of the first elastomer layer. [8] The anisotropic conductive sheet according to any one of [1] to [7], wherein a ratio T2 / T1 of a thickness T2 of the second elastomer layer to a thickness T1 of the first elastomer layer is 1.5 to 5. [9] The anisotropic conductive sheet according to any one of [1] to [8], wherein the ratio Z2 / Z1 of the total thickness Z2 of the elastomer layers other than the elastomer layer with the highest hardness to the total thickness Z1 of the elastomer layer with the highest hardness among the elastomer layers included in the insulating layer is 1.5 to 5.

[10] The anisotropic conductive sheet according to any one of [1] to [9], wherein the first elastomer layer and the second elastomer layer each contain a crosslinked product of a silicone rubber composition.

[11] The anisotropic conductive sheet according to any of [1] to

[10] , wherein the insulating layer further comprises one or more first surface resin layers arranged on a surface of the first elastomer layer opposite to the second elastomer layer and constituting the first surface, and one or more second surface resin layers arranged on a surface of the second elastomer layer opposite to the first elastomer layer and constituting the second surface, wherein the storage modulus at 25°C of the one or more first surface resin layers and the one or more second surface resin layers is higher than the storage modulus at 25°C of the first elastomer layer and the second elastomer layer.

[12] The anisotropic conductive sheet described in

[11] , wherein the insulating layer further has an intermediate resin layer disposed between the first elastomer layer and the second elastomer layer, and the storage modulus of the intermediate resin layer at 25°C is higher than the storage modulus of the first elastomer layer and the second elastomer layer at 25°C.

[13] The anisotropic conductive sheet according to

[11] or

[12] , wherein the one or more first surface resin layers are a plurality of first surface resin layers, the one or more second surface resin layers are a plurality of second surface resin layers, each disposed on the plurality of first surface resin layers, the plurality of first conductive layers are each disposed on the plurality of first surface resin layers, and the plurality of second conductive layers are each disposed on the plurality of second surface resin layers.

[14] An electrical inspection device comprising: a testing board having a plurality of electrodes; and an anisotropic conductive sheet according to any one of [1] to

[13] , which is placed on a surface of the testing board on which the plurality of electrodes are arranged, and an object to be inspected is placed on the side of the first surface.

[15] An electrical inspection method comprising the steps of: stacking a testing board having a plurality of electrodes and an object to be inspected having terminals via an anisotropic conductive sheet described in any one of [1] to

[13] ; and electrically connecting the electrodes of the testing board and the terminals of the object to be inspected via the anisotropic conductive sheet; the object to be inspected is placed on the first surface side. Effect of the Invention

[0010] According to the present invention, it is possible to provide an anisotropic conductive sheet, an electrical inspection device, and an electrical inspection method in which the conductive layer is less likely to break and the electrical resistance is less likely to increase even when subjected to repeated indentation loads. [Brief description of the drawings]

[0011] [Figure 1] 1A and 1B are schematic diagrams of the anisotropic conductive sheet of Patent Document 1. [Diagram 2] FIG. 2A is a schematic partially enlarged plan view of the anisotropic conductive sheet according to the present embodiment, and FIG. 2B is a schematic partially enlarged cross-sectional view taken along line 2B-2B in FIG. 2A. [Diagram 3] 3A and 3B are schematic enlarged plan views showing modified examples of the first conductive layer. [Figure 4] 4A to 4F are schematic partially enlarged cross-sectional views showing a method for producing an anisotropic conductive sheet according to the present embodiment. [Diagram 5] 5A and 5B are schematic partially enlarged cross-sectional views showing a method for producing an anisotropic conductive sheet according to the present embodiment. [Figure 6] FIG. 6A is a schematic plan view of an anisotropic conductive sheet cut out in accordance with the present embodiment and fixed to a frame, and FIG. 6B is a schematic cross-sectional view of the framed anisotropic conductive sheet of FIG. 6A taken along line 6B-6B. [Figure 7] FIG. 7 is a schematic cross-sectional view of an electrical inspection device according to this embodiment. [Figure 8] 8A to 8C are schematic partially enlarged cross-sectional views showing a method for manufacturing an anisotropic conductive sheet according to a modified example. [Figure 9] FIG. 9A is a schematic cross-sectional view showing the configuration of an electrical inspection device in an embodiment, and FIG. 9B is an image showing the terminal surface of a test chip. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 1. Anisotropic conductive sheet Fig. 2A is a schematic partially enlarged plan view of an anisotropic conductive sheet 100 according to an embodiment of the present invention, and Fig. 2B is a schematic partially enlarged cross-sectional view of the anisotropic conductive sheet 100 of Fig. 2A taken along line 2B-2B. Figs. 3A and 3B are schematic enlarged plan views showing modified examples of the first conductive layer 122A.

[0013] As shown in FIGS. 2A and 2B, the anisotropic conductive sheet 100 according to the present embodiment has an insulating layer 110, a plurality of conductive layers 120, and a plurality of conductive fillers .

[0014] 1-1. Insulating layer 110 The insulating layer 110 has a first surface 110a on one side in the thickness direction, a second surface 110b on the other side, and a plurality of through holes 115 penetrating from the first surface 110a to the second surface 110b (see FIG. 2B). In this embodiment, an object to be inspected is placed on the first surface 110a.

[0015] In addition, in this embodiment, the insulating layer 110 includes a first elastomer layer 111A, a second elastomer layer 111B, one or more first surface resin layers 112A, one or more second surface resin layers 112B, an intermediate resin layer 113, and four primer layers 114 (see FIG. 2B).

[0016] Here, the first elastomer layer 111A and the second elastomer layer 111B are layers containing an elastic material and can impart elasticity to the insulating layer 110. However, if these elastomer layers have the same hardness, when an object to be inspected is placed on the first surface 110a and pressed, the pressing load is likely to concentrate on the first elastomer layer 111A on the first surface 110a side, and the amount of distortion of the elastomer layer on the first surface 110a side is likely to increase. This makes it easier for cracks and breakage to occur in the conductive layer 120 on the first surface 110a side. In particular, when the intermediate resin layer 113 is present, the pressing load is less likely to be distributed, making it easier for breakage and the like to occur in the conductive layer 120 on the first surface 110a side.

[0017] In contrast, in this embodiment, the hardness of the second elastomer layer 111B on the second surface 110b side, which is away from the first surface 110a on which the test object is placed, is made lower than the hardness of the first elastomer layer 111A on the first surface 110a side. This makes it possible to make the second elastomer layer 111B more easily distorted and the first elastomer layer 111A less easily distorted when an indentation load is applied to the first surface 110a. That is, the indentation load concentrated on the first elastomer layer 111A can be dispersed to the second elastomer layer 111B. This makes it possible to suppress breakage of the conductive layer 120 on the first surface 110a. Each layer will be specifically described below.

[0018] (First elastomer layer 111A) As described above, the first elastomer layer 111A is a layer that contains an elastic material. The first elastomer layer 111A is disposed closer to the first surface 110a than the second elastomer layer 111B.

[0019] As described above, the hardness of the first elastomer layer 111A may be higher than the hardness of the second elastomer layer 111B. The hardness of the first elastomer layer 111A is preferably 30 or more, more preferably 40 or more, and even more preferably 50 or more. When the hardness of the first elastomer layer 111A is 30 or more, the amount of distortion of the first elastomer layer 111A when a pressing load is applied can be reduced, so that the conductive layer 120 on the first surface 110a side receiving the pressing load is less likely to break. On the other hand, the upper limit of the hardness of the first elastomer layer 111A is preferably 100 or less, more preferably 90 or less, from the viewpoint of maintaining the elastic deformability of the insulating layer 110. The hardness of the first elastomer layer 111A can be adjusted by the crosslinking degree of the crosslinked product of the rubber composition described later and the content of the filler.

[0020] The hardness of the first elastomer layer 111A can be measured by a durometer (type A) in accordance with ASTM D 2240 (JIS K 6253-2012). Specifically, the first elastomer layer 111A is cut out to obtain a sample piece having a thickness of 10 mm. The hardness of this sample piece can be measured at 23° C. using a type A durometer tester.

[0021] The storage modulus of the first elastomer layer 111A at 25° C. is lower than the storage modulus of the first outer resin layer 112A and the intermediate resin layer 113 at 25° C. Also, the storage modulus of the first elastomer layer 111A at 25° C. is higher than the storage modulus of the second elastomer layer 111B at 25° C. The storage modulus of the first elastomer layer 111A at 25° C. is 1.0×10 7 Pa or less, and 1.0×10 5 ~9.0×10 6 It is more preferably in Pa. The storage modulus can be measured in accordance with JIS K 7244-1:1998 / ISO6721-1:1994.

[0022] The glass transition temperature of the first elastomer layer 111A is not particularly limited, but from the viewpoint of preventing damage to the terminals of the test object, it is preferably −30° C. or lower, and more preferably −40° C. or lower. The glass transition temperature can be measured in accordance with JIS K 7095:2012.

[0023] The hardness, storage modulus, and glass transition temperature of first elastomer layer 111A can be adjusted by the type and composition of the elastic material.

[0024] That is, the elastic material constituting the first elastomer layer 111A is not particularly limited as long as it satisfies the above-mentioned hardness relationship. Examples of the elastic material may include a crosslinked product of a rubber composition containing silicone rubber, urethane rubber (urethane polymer), acrylic rubber (acrylic polymer), ethylene-propylene-diene copolymer (EPDM), chloroprene rubber, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polybutadiene rubber, natural rubber, fluorine-based rubber, etc., or a thermoplastic elastomer composition containing a polyester-based thermoplastic elastomer, an olefin-based thermoplastic elastomer, etc. Among them, a crosslinked product of a rubber composition is preferable, and a crosslinked product of a silicone rubber composition is preferable. The silicone rubber may be any of an addition type, a condensation type, and a radical type.

[0025] The rubber composition may further contain a crosslinking agent as necessary. The crosslinking agent may be appropriately selected depending on the type of rubber. For example, examples of crosslinking agents for silicone rubber include addition reaction catalysts such as metals, metal compounds, and metal complexes (platinum, platinum compounds, and complexes thereof) having catalytic activity for hydrosilylation reactions; and organic peroxides such as benzoyl peroxide, bis-2,4-dichlorobenzoyl peroxide, dicumyl peroxide, and di-t-butyl peroxide. Examples of crosslinking agents for acrylic rubber include epoxy compounds, melamine compounds, and isocyanate compounds.

[0026] For example, examples of crosslinked rubber compositions containing silicone rubber include an addition crosslinked product of a composition containing an organopolysiloxane having a hydrosilyl group (SiH group), an organopolysiloxane having a vinyl group, and an addition reaction catalyst; an addition crosslinked product of a composition containing an organopolysiloxane having a vinyl group and an addition reaction catalyst; and a crosslinked product of a composition containing an organopolysiloxane having a SiCH3 group and an organic peroxide curing agent.

[0027] The rubber composition may further contain other components such as a silane coupling agent, a filler, etc. Examples of the filler include silica particles.

[0028] The thickness of first elastomer layer 111A is not particularly limited, but is preferably thinner than the thickness of second elastomer layer 111B in order to further increase the elasticity of the entire insulating layer 110. The thickness of first elastomer layer 111A may be, for example, 10 to 300 μm, and preferably 20 to 150 μm.

[0029] (Second elastomer layer 111B) Second elastomer layer 111B is a layer containing an elastic material, similar to first elastomer layer 111A. Second elastomer layer 111B is disposed closer to second surface 110b than first elastomer layer 111A.

[0030] As described above, the hardness of the second elastomer layer 111B may be lower than the hardness of the first elastomer layer 111A. The hardness of the second elastomer layer 111B is preferably, for example, 80 or less, more preferably less than 50, more preferably 40 or less, and even more preferably 30 or less. When the hardness of the second elastomer layer 111B is 80 or less, the second elastomer layer 111B is more likely to disperse the indentation load, so that the amount of distortion of the first elastomer layer 111A can be reduced. On the other hand, the lower limit of the hardness of the second elastomer layer 111B is preferably, for example, 10 or more, more preferably 20 or more. When the hardness of the second elastomer layer 111B is 10 or more, the amount of distortion of the second elastomer layer 111B is less likely to be excessive, so that the breakage of the conductive layer 120 near the second elastomer layer 111B can be more effectively prevented. From these viewpoints, the hardness of the second elastomer layer 111B is preferably 10 or more and less than 50, for example.

[0031] The difference in hardness between the first elastomer layer 111A and the second elastomer layer 111B is preferably 10 or more. When the difference in hardness is 10 or more, the hardness of the second elastomer layer 111B is smaller, so that the indentation load can be more dispersed. From the same viewpoint, the difference in hardness is more preferably 10 to 60, and more preferably 20 to 50.

[0032] The storage modulus of second elastomer layer 111B at 25° C. may be the same as above, except that it is lower than the storage modulus of first elastomer layer 111A at 25° C. In addition, the glass transition temperature of second elastomer layer 111B may also be the same as above.

[0033] The elastic material constituting the second elastomer layer 111B is not particularly limited as long as it satisfies the above-mentioned hardness relationship, and the same elastic material as the above-mentioned can be used. In the present embodiment, the second elastomer layer 111B preferably contains a cross-linked product of a rubber composition, and more preferably contains a cross-linked product of a silicone rubber composition.

[0034] The hardness of second elastomer layer 111B can be adjusted by the composition and crosslinking degree of the elastic material, the filler content, etc. For example, the crosslinking degree of the crosslinked product of second elastomer layer 111B may be lower than the crosslinking degree of the crosslinked product of first elastomer layer 111A. Also, the filler content of second elastomer layer 111B may be lower than the filler content of first elastomer layer 111A.

[0035] The thickness of second elastomer layer 111B is not particularly limited, but is preferably thicker than first elastomer layer 111A in order to maintain the elastic deformation of insulating layer 110 as a whole. The thickness of second elastomer layer 111B may be, for example, 20 to 1000 μm, and preferably 30 to 800 μm.

[0036] When the thickness of second elastomer layer 111B is T2 and the thickness of first elastomer layer 111A is T1, the thickness ratio T2 / T1 is preferably 1.5 to 5 (see FIG. 2B). When the thickness ratio T2 / T1 is 1.5 or more, the indentation load can be further dispersed by second elastomer layer 111B. When the thickness ratio T2 / T1 is 5 or less, the elasticity of insulating layer 110 can be prevented from becoming excessive.

[0037] (1st surface resin layer 112A) The one or more first surface resin layers 112A are layers containing resin and can impart appropriate rigidity to the insulating layer 110. The one or more first surface resin layers 112A are disposed on the surface of the first elastomer layer 111A opposite to the second elastomer layer 111B, and constitute the first surface 110a of the insulating layer 110.

[0038] The one or more first surface resin layers 112A may be one continuous layer that is not completely divided by the first groove portion 116a, or may be multiple layers that are completely divided by the first groove portion 116a. In this embodiment, the one or more first surface resin layers 112A are multiple first surface resin layers 112A that are completely divided by the first groove portion 116a (see FIG. 2B). The multiple first surface resin layers 112A are disposed on the first elastomer layer 111A and spaced apart from each other.

[0039] The storage modulus of the first surface resin layer 112A at 25° C. is higher than the storage modulus of the first elastomer layer 111A and the second elastomer layer 111B at 25° C. Therefore, even if heating is performed during electrical inspection, the thermal fluctuation of the distance between the centers of gravity of the multiple conductive layers 120 can be suppressed.

[0040] The storage modulus of the first outer resin layer 112A at 25° C. may be higher than the storage modulus of the first elastomer layer 111A and the second elastomer layer 111B at 25° C., and may be, for example, 1.0×10 8 ~1.0×10 10 Pa is preferably 1.0×10 8 ~8.0×10 9 It is more preferable that the storage modulus is 100 to 100,000 Pa. The ratio (G3 / G1) of the storage modulus G3 at 25° C. of the first outer resin layer 112A to the storage modulus G1 at 25° C. of the first elastomer layer 111A or the second elastomer layer 111B may be, for example, 100 to 100,000.

[0041] The linear expansion coefficient of the first surface resin layer 112A is preferably lower than the linear expansion coefficients of the first elastomer layer 111A and the second elastomer layer 111B. Specifically, the linear expansion coefficient of the first surface resin layer 112A is preferably 60 ppm / K or less, and more preferably 50 ppm / K or less.

[0042] The glass transition temperature of the first surface resin layer 112A is preferably higher than the glass transition temperatures of the first elastomer layer 111A and the second elastomer layer 111B. Specifically, since the electrical inspection is performed at approximately -40 to 150°C, the glass transition temperature of the first surface resin layer 112A is preferably 150°C or higher, and more preferably 150 to 500°C. The glass transition temperature can be measured by the same method as described above.

[0043] The material constituting the first outer resin layer 112A is not particularly limited as long as it contains at least a resin whose storage modulus satisfies the above range. Examples of the resin contained in the first outer resin layer 112A include engineering plastics such as polyamide, polycarbonate, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, and polyetherimide, acrylic resin, urethane resin, epoxy resin, and olefin resin. Among them, the first outer resin layer 112A preferably contains a heat-resistant resin whose glass transition temperature satisfies the above range, and more preferably contains polyimide. The first outer resin layer 112A may further contain other components such as a filler as necessary.

[0044] The thickness of the first surface resin layer 112A is not particularly limited, but from the viewpoint of further increasing the elasticity of the insulating layer 110, it is preferable that the thickness is thinner than the thickness of the first elastomer layer 111A (see FIG. 2B). Specifically, the ratio (T3 / T1) of the thickness (T3) of the first surface resin layer 112A to the thickness (T1) of the first elastomer layer 111A is preferably, for example, 0.01 to 0.2, and more preferably 0.02 to 0.15. When the ratio of the thickness of the first surface resin layer 112A is equal to or greater than a certain value, the insulating layer 110 can be given an appropriate stiffness without impairing the elastic deformation of the insulating layer 110. This not only improves the handling property, but also suppresses the fluctuation of the center-to-center distance of the plurality of through holes 115 due to heat.

[0045] (Second surface resin layer 112B) The one or more second surface resin layers 112B are layers containing resin, similar to the one or more first surface resin layers 112A. The one or more second surface resin layers 112B are disposed on the surface of the second elastomer layer 111B opposite to the first elastomer layer 111A, and constitute the second surface 110b of the insulating layer 110.

[0046] The one or more second surface resin layers 112B may be one continuous layer that is not completely divided by the second groove portion 116b, or may be multiple layers that are completely divided by the second groove portion 116b. In this embodiment, the one or more second surface resin layers 112B are multiple second surface resin layers 112B that are completely divided by the second groove portion 116b (see FIG. 2B). The multiple second surface resin layers 112B are disposed on the second elastomer layer 111B and spaced apart from each other.

[0047] The second outer resin layer 112B has the same or similar structure as the first outer resin layer 112A described above, and detailed description thereof will be omitted. That is, the shape, material, and physical properties of the second outer resin layer 112B may be the same or similar to the shape, material, and physical properties of the first outer resin layer 112A described above.

[0048] The composition of the first outer resin layer 112A may be different from the composition of the second outer resin layer 112B. The thickness of the first outer resin layer 112A may be different from the thickness of the second outer resin layer 112B, but is preferably the same from the viewpoint of suppressing warping of the anisotropic conductive sheet 100, and the ratio of the thickness of the second outer resin layer 112B to the thickness of the first outer resin layer 112A may be, for example, 0.8 to 1.2.

[0049] (Intermediate resin layer 113) The intermediate resin layer 113 is also a layer containing resin, similar to the first outer resin layer 112A and the second outer resin layer 112B. The intermediate resin layer 113 is disposed between the first elastomer layer 111A and the second elastomer layer 111B.

[0050] The storage modulus of intermediate resin layer 113 at 25° C. is higher than the storage modulus of first elastomer layer 111A and second elastomer layer 111B at 25° C. Such intermediate resin layer 113 can impart appropriate rigidity to insulating layer 110, and can reduce dimensional change, for example, when a sheet is cut to a predetermined size.

[0051] The storage modulus, glass transition temperature, and linear expansion coefficient of the intermediate resin layer 113 at 25° C. may be the same as or similar to the storage modulus, glass transition temperature, and linear expansion coefficient of the first outer resin layer 112A at 25° C. The resin composition constituting the intermediate resin layer 113 may be the same as or similar to the resin composition constituting the first outer resin layer 112A.

[0052] The storage modulus, glass transition temperature and linear expansion coefficient of the intermediate resin layer 113 at 25° C. may be different from those of the first surface resin layer 112A at 25° C. For example, the storage modulus of the intermediate resin layer 113 may be higher or lower than those of the first surface resin layer 112A. Furthermore, the composition of the intermediate resin layer 113 may be different from the composition of the first surface resin layer 112A.

[0053] The thickness of the intermediate resin layer 113 may be the same as or different from the thickness of the first outer resin layer 112A. For example, the thickness of the intermediate resin layer 113 may be thicker than the thickness of the first outer resin layer 112A (see FIG. 2B) or thinner. The ratio (T4 / T1) of the thickness (T4) of the intermediate resin layer 113 to the thickness (T1) of the first elastomer layer 111A is, for example, preferably 0.01 to 0.15, and more preferably 0.05 to 0.1. The ratio (T4 / T) of the thickness (T4) of the intermediate resin layer 113 to the thickness (T) of the insulating layer 110 can be 0.005 to 0.1, and preferably 0.008 to 0.08. The thickness of the intermediate resin layer 113 can be, for example, 5 to 20 μm.

[0054] (Primer layer 114) The four primer layers 114 are respectively disposed between the first elastomer layer 111A and the first surface resin layer 112A, between the first elastomer layer 111A and the intermediate resin layer 113, between the second elastomer layer 111B and the intermediate resin layer 113, and between the second elastomer layer 111B and the second surface resin layer 112B, which can enhance the adhesion between the layers (see FIG. 2B).

[0055] The primer layer 114 preferably contains a polycondensate of a metal alkoxide. The polycondensate of a metal alkoxide exhibits good affinity to both organic compounds such as heat-resistant resins and inorganic compounds such as silicone compounds. Therefore, the primer layer 114 exhibits good affinity to both the first outer resin layer 112A containing, for example, a heat-resistant resin and the first elastomer layer 111A containing, for example, a cross-linked product of a silicone rubber composition, and can enhance the adhesion between these layers.

[0056] The primer layer 114 is obtained by polycondensing a metal alkoxide by a sol-gel method in a primer solution containing a metal alkoxide and an organic solvent or water.

[0057] The metal alkoxide is represented by the following general formula (1). Formula (1):R 1 n M(OR 2 )m

[0058] In formula (1), M represents a metal atom. Examples of the metal atom include silicon, zirconium, titanium, aluminum, etc., and is preferably silicon. R 1 and R 2 are each an organic group having a carbon number of 1 to 8. Examples of the organic group include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and an i-butyl group. m represents an integer of 1 or more, n represents an integer of 0 or more, and n+m represents the valence of M.

[0059] Examples of metal alkoxides represented by formula (1) include alkoxysilanes such as tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, p-styryltrimethoxysilane, 3-chloropropyltriethoxysilane, trifluoromethyltrimethoxysilane, and trifluoromethyltriethoxysilane, as well as corresponding alkoxyaluminum, alkoxyzirconium, and alkoxytitanium.

[0060] The content of the metal alkoxide may be 50% by mass or more, and preferably 70 to 100% by mass, based on the non-volatile components of the primer solution.

[0061] The thickness of primer layer 114 is not particularly limited, but is, for example, 0.01 to 5 μm, and preferably 0.05 to 3 μm. Whether primer layer 114 is present or not can be confirmed, for example, by observing a cross section using an electron microscope.

[0062] (other layers) Insulating layer 110 may further include layers other than those described above as necessary. The other layers may include, for example, an adhesive layer. The adhesive layer may be an elastomer layer different from first elastomer layer 111A and second elastomer layer 111B.

[0063] (Through hole 115) The plurality of through holes 115 are holes that penetrate from the first surface 110a to the second surface 110b of the insulating layer 110 (see FIG. 2B).

[0064] The axial direction of the through hole 115 may be approximately parallel to the thickness direction of the insulating layer 110 or may be inclined. Approximately parallel means that the angle with respect to the thickness direction of the insulating layer 110 is 10° or less. Inclined means that the angle with respect to the thickness direction of the insulating layer 110 is more than 10° and 50° or less, preferably 20 to 45°. In this embodiment, the axial direction of the through hole 115 is approximately parallel to the thickness direction of the insulating layer 110 (see FIG. 2B). The axial direction means the direction of a line connecting the centers of gravity of the opening of the through hole 115 on the first surface 110a side and the opening on the second surface 110b side.

[0065] The shape of the opening of through-hole 115 in first surface 110a is not particularly limited and may be, for example, a circle, a rectangle, another polygon, etc. In this embodiment, the shape of the opening of through-hole 115 in first surface 110a is a circle (see FIG. 2A).

[0066] The circle-equivalent diameter D of the opening of the through-hole 115 on the first surface 110a side is not particularly limited, and is preferably 1 to 330 μm, more preferably 2 to 200 μm, and further preferably 10 to 100 μm (see FIG. 2B). The circle-equivalent diameter D of the opening of the through-hole 115 on the first surface 110a side refers to the circle-equivalent diameter (diameter of a perfect circle equivalent to the area of ​​the opening) of the through-hole 115 when viewed along the axial direction of the through-hole 115 from the first surface 110a side. The circle-equivalent diameter D of the opening of the through-hole 115 on the first surface 110a side and the circle-equivalent diameter D of the opening of the through-hole 115 on the second surface 110b side may be the same or different.

[0067] The center-to-center distance (pitch) p of the openings of the plurality of through holes 115 on the first surface 110a side is not particularly limited and can be appropriately set in accordance with the pitch of the terminals of the test object (see FIG. 2B). Since the pitch of the terminals of the HBM (High Bandwidth Memory) as the test object is 55 μm and the pitch of the terminals of the PoP (Package on Package) is 400 to 650 μm, the center-to-center distance p of the openings of the plurality of through holes 115 can be, for example, 5 to 650 μm. In particular, from the viewpoint of making it alignment-free, it is more preferable that the center-to-center distance p of the openings of the plurality of through holes 115 on the first surface 110a side is 5 to 55 μm. The center-to-center distance p of the openings of the plurality of through holes 115 on the first surface 110a side refers to the minimum value of the center-to-center distances of the openings of the plurality of through holes 115 on the first surface 110a side. The center of the opening of the through hole 115 is the center of gravity of the opening. The center-to-center distance between the openings of the plurality of through-holes 115 on the first surface 110a side and the center-to-center distance between the openings of the plurality of through-holes 115 on the second surface 110b side may be the same or different.

[0068] The ratio T / D of the axial length of through hole 115 (thickness T of insulating layer 110) to the circle-equivalent diameter D of the opening of through hole 115 on the first surface 110a side is not particularly limited, but is preferably 3 to 40 (see FIG. 2B).

[0069] (insulation layer thickness) The thickness (T) of the insulating layer 110 is not particularly limited as long as it is sufficient to ensure insulation in the non-conductive portions, and may be, for example, 40 to 700 μm, and preferably 100 to 400 μm.

[0070] 1-2. Conductive layer 120 The multiple conductive layers 120 are arranged corresponding to one or more through holes 115. The conductive layers 120 include one or more conductive portions 121, a first conductive layer 122A, and a second conductive layer 122B (see FIG. 2B).

[0071] The conductive portion 121 is disposed on the inner wall surface of the through hole 115 .

[0072] The first conductive layer 122A is disposed on the first surface 110a of the insulating layer 110 (on the first outer resin layer 112A in this embodiment) and is connected to one or more conductive portions 121. The multiple first conductive layers 122A are disposed spaced apart from one another via the first groove portion 116a. The second conductive layer 122B is disposed on the second surface 110b of the insulating layer 110 (on the second outer resin layer 112B in this embodiment) and is connected to one or more conductive portions 121. The multiple second conductive layers 122B are disposed spaced apart from each other via the second groove portion 116b.

[0073] In a plan view of the insulating layer 110, the shapes of the first conductive layer 122A and the second conductive layer 122B are not particularly limited and may be any of a rectangle, a triangle, other polygons, a circle, and the like. In this embodiment, the shapes of the first conductive layer 122A and the second conductive layer 122B are both rectangular (see FIG. 2A). In this embodiment, the shapes and sizes of the multiple first conductive layers 122A are all the same, and the shapes and sizes of the multiple second conductive layers 122B are all the same.

[0074] In addition, in a plan view of the insulating layer 110, the first conductive layer 122A may be located inside the outer edge of the first surface resin layer 112A. Similarly, the second conductive layer 122B may be located inside the outer edge of the second surface resin layer 112B.

[0075] Further, in this embodiment, one first conductive layer 122A is arranged for each through hole 115, however, this is not limited thereto, and one first conductive layer 122A may be arranged for two or more through holes 115 (see Figures 3A and 3B).

[0076] The volume resistivity of the material constituting the conductive layer 120 is not particularly limited as long as sufficient electrical conductivity can be obtained. For example, -4 It is preferable that the resistance is Ω·m or less, and 1.0×10 -5 ~1.0×10 -9 It is more preferable that the volume resistivity is Ω·m. The volume resistivity can be measured by the method described in ASTM D 991.

[0077] The material constituting the conductive layer 120 may have a volume resistivity that satisfies the above range. Examples of materials constituting the conductive layer 120 include metal materials such as copper, gold, platinum, silver, nickel, tin, iron, or an alloy of one of these metals, and carbon materials such as carbon black. In particular, from the viewpoint of having high conductivity and flexibility, the conductive layer 120 preferably contains one or more selected from the group consisting of gold, silver, and copper as a main component. "Containing as a main component" means, for example, that the conductive layer 120 contains 70 mass % or more, preferably 80 mass % or more.

[0078] The materials constituting conductive portion 121, first conductive layer 122A, and second conductive layer 122B may be the same or different, but are preferably the same from the viewpoints of ease of manufacture and ease of achieving stable conduction.

[0079] The thickness (t) of the conductive layer 120 may be within a range that is sufficient to obtain electrical continuity and does not block the through-hole 115, and may be, for example, 0.1 to 5 μm. In the conductive layer 120, the thickness of the conductive portion 121 is in a direction perpendicular to the thickness direction of the insulating layer 110, and the thicknesses of the first conductive layer 122A and the second conductive layer 122B are in a direction parallel to the thickness direction of the insulating layer 110 (see FIG. 2B).

[0080] The first grooves 116a disposed between the multiple first conductive layers 122A are recesses disposed on the first surface 110a.

[0081] The cross-sectional shape of the first groove portion 116a in a direction perpendicular to the extension direction is not particularly limited, and may be any of a rectangle, a semicircle, a U-shape, and a V-shape. In the present embodiment, the cross-sectional shape of the first groove portion 116a is a rectangle.

[0082] It is preferable that the width w and depth d of the first groove portion 116a be set within a range in which the first conductive layer 122A on one side does not come into contact with the first conductive layer 122A on the other side via the first groove portion 116a when a pressing load is applied (see FIG. 2B).

[0083] The width w of the first groove portion 116a is the maximum width in a direction perpendicular to the direction in which the first groove portion 116a extends on the first surface 110a (see FIG. 2B).

[0084] The depth d of the first groove 116a is not particularly limited, but is preferably equal to or greater than the thickness of the first surface resin layer 112A. That is, the deepest part of the first groove 116a may be located on the surface of the first elastomer layer 111A or inside the surface. The depth d of the first groove 116a refers to the depth from the surface to the deepest part of the first conductive layer 122A in the thickness direction of the insulating layer 110 (see FIG. 2B). By dividing the first surface resin layer 112A into a plurality of parts by the first groove 116a, it is possible to prevent the surrounding conductive layer 120 from being pressed in when the inspection target 520 is placed and pressed in.

[0085] The second grooves 116b arranged between the multiple second conductive layers 122B on the second surface 110b may be the same as or similar to the first grooves 116a arranged between the multiple first conductive layers 122A on the first surface 110a.

[0086] 1-3.Conductive filling material 130 The multiple conductive fillers 130 are filled inside the multiple through holes 115, specifically, inside the cavities 115' of the through holes 115 surrounded by the conductive portions 121. This can increase the conductivity of the anisotropic conductive sheet 100 while suppressing peeling of the conductive portions 121.

[0087] The conductive filler 130 includes a crosslinked product of a conductive rubber composition that includes conductive particles and a rubber component.

[0088] The material constituting the conductive particles is not particularly limited, but from the viewpoint of excellent conductivity and flexibility, particles containing one or more elements selected from the group consisting of gold, silver, and copper are preferred.

[0089] The type of rubber component is not particularly limited, and may be the same as the rubber component constituting first elastomer layer 111A and second elastomer layer 111B (hereinafter, these are also collectively referred to as "elastomer layer 111"). The type of rubber component constituting conductive filler 130 may be the same as or different from the type of rubber component constituting elastomer layer 111. From the viewpoint of flexibility, etc., silicone rubber is preferable.

[0090] The content of the rubber component is preferably 5 to 50 mass % based on the total amount of the conductive particles and the rubber component. When the content of the rubber component is 5 mass % or more, the adhesion of the conductive part 121 to the inner wall surface of the through hole 115 is easily increased, and the cross-linked product of the conductive rubber composition has sufficient flexibility, so that cracks and peeling of the conductive part 121 are easily suppressed.

[0091] The conductive rubber composition may further contain other components such as a crosslinking agent as necessary. The type of crosslinking agent is not particularly limited, and the same crosslinking agent as that used in the rubber composition constituting the elastomer layer 111 can be used.

[0092] The storage modulus at 25°C of the crosslinked product of the conductive rubber composition constituting the conductive filler 130 is not particularly limited, but is usually likely to be higher than the storage modulus at 25°C of the crosslinked product of the rubber composition constituting the elastomer layer 111. However, from the viewpoint of suppressing defects caused by the pressure during pressing being concentrated on the conductive filler 130, it is preferable that the storage modulus is moderately low. Specifically, the storage modulus at 25°C of the crosslinked product of the conductive rubber composition is preferably 0.1 to 30 MPa, more preferably 0.2 to 20 MPa. The storage modulus can be measured in a compression deformation mode by the same method as above.

[0093] The volume resistivity of the crosslinked conductive rubber composition is 10 ―2 It is preferable that the resistance is Ω·m or less, and 1×10 -8 ~1×10 -2 It is more preferable that the volume resistivity is Ω·m. The volume resistivity can be measured in the same manner as above.

[0094] 1-4.Other As described above, the anisotropic conductive sheet 100 may have one or more electrode regions in which a plurality of conductive layers 120 and a plurality of conductive fillers 130 are formed on the insulating layer 110 . On the surface of the anisotropic conductive sheet 100, the periphery of the electrode region may be surrounded by a first exposed portion 140a where the insulating layer 110 is exposed by not arranging a conductive layer or the like (see FIG. 2A). As a result, when cutting out the anisotropic conductive sheet 100 into individual electrode regions, cutting along the first exposed portion 140a can reduce the generation of chips of the conductive layer 120 (which may cause foreign matter).

[0095] 2. Manufacturing method of anisotropic conductive sheet 4A to 4F, 5A and 6B are schematic enlarged partial cross-sectional views showing a method for producing the anisotropic conductive sheet 100. In FIG.

[0096] In this embodiment, the anisotropic conductive sheet 100 is 1) A step of obtaining a laminated sheet 150 including at least a first elastomer layer 111A, a second elastomer layer 111B, a first outer resin layer 112A, a second outer resin layer 112B, and an intermediate resin layer 113 (see FIG. 4A ); 2) forming a plurality of through holes 115 in the laminated sheet 150 (see FIG. 4B); 3) forming one continuous conductive layer 151 in each area of ​​the laminated sheet 150 where the through holes 115 are formed (see FIG. 4C ); 4) filling the inside of the plurality of through holes 115 with a conductive rubber composition L (see FIG. 4D ); and 5) A process of forming a plurality of first grooves 116a and a plurality of second grooves 116b on the first surface 150a and the second surface 150b of the laminated sheet 150, and dividing the portion of the conductive layer 151 on the first surface 150a side into a plurality of first conductive layers 122A and the portion on the second surface 150b side into a plurality of second conductive layers 122B (see FIGS. 4E and 4F). It can be manufactured through the following steps.

[0097] Regarding step 1) First, there is prepared a laminate sheet 150 including a first elastomer layer 111A, a second elastomer layer 111B, a first outer resin layer 112A, a second outer resin layer 112B, and an intermediate resin layer 113. The laminate sheet 150 can be manufactured by any method, and can be manufactured, for example, by the following procedure.

[0098] (Preparation of surface sheets S1-A and S1-B) A primer layer 114 and a first elastomer layer 111A are formed in this order on one surface of the first outer resin layer 112A to obtain the outer sheet S1-A (see FIG. 5A). Similarly, a primer layer 114 and a second elastomer layer 111B are formed in that order on one surface of the second outer resin layer 112B to obtain the outer sheet S1-B (see FIG. 5A).

[0099] The primer layer 114 can be formed by applying a solution containing the above-mentioned metal alkoxide, followed by drying and heating, thereby polycondensing the metal alkoxide by a sol-gel method.

[0100] The first elastomer layer 111A and the second elastomer layer 111B may be formed by applying a liquid rubber composition onto the primer layer 114 and then drying or crosslinking the composition, or may be formed by laminating an elastomer sheet onto the primer layer 114, optionally via an adhesive layer.

[0101] The adhesive layer may be formed, for example, by applying, drying, or heating a rubber composition. The rubber composition is preferably the same as the rubber composition contained in the elastomer sheet, and is preferably a silicone rubber composition. Examples of such rubber compositions include two-liquid additive liquid silicone rubber compositions (KE2061-50-A / B, KE2061-70-A / B, etc., manufactured by Shin-Etsu Silicone Co., Ltd.). The thickness of the adhesive layer may be much thinner than the thickness of the elastomer sheet, for example, 5 μm or less.

[0102] (Preparation of intermediate sheet S2) A primer layer 114 is formed on each of both sides of the intermediate resin layer 113 to obtain an intermediate sheet S2 (see FIG. 5A).

[0103] The primer layer 114 can be formed in the same manner as described above.

[0104] (Joining) The surface layer sheet S1-A, the intermediate sheet S2, and the surface layer sheet S1-B prepared above are laminated and bonded together (see Figs. 5A and 5B). The bonding can be performed by heating the laminated assembly with a hot plate or the like.

[0105] In order to increase the bonding strength, the first elastomer layer 111A of the surface sheet S1-A and the second elastomer layer 111B of the surface sheet S1-B may be subjected to a surface treatment such as plasma irradiation before bonding. For example, when these elastomer layers contain a cured product of a silicone rubber composition, silanol groups (Si-OH) are generated by plasma irradiation. These silanol groups can further increase the adhesion with the primer layer 114.

[0106] In addition, in Fig. 5A and 5B, the primer layer 114 of the intermediate sheet S2 and the first elastomer layer 111A of the surface sheet S1-A are bonded to each other, but this is not limited thereto. For example, an adhesive layer containing a crosslinked product of a silicone rubber composition may be further formed on the primer layer 114 of the intermediate sheet S2. Then, after the adhesive layer is irradiated with plasma, it may be bonded to the plasma-treated surface of the first elastomer layer 111A of the surface sheet S1-A. This allows for good bonding by condensation reaction between silanol groups. In this case, the heating temperature may be any temperature that allows bonding, and may be, for example, a temperature at which condensation reaction between silanol groups occurs.

[0107] Regarding step 2) Next, a plurality of through holes 115 are formed in a predetermined region of the laminated sheet 150 (see FIG. 4B). The through holes 115 can be formed by any method, for example, by mechanical processing (e.g., pressing or punching) or by a laser processing method. Among these, it is more preferable to form the through holes 115 by a laser processing method, since it is possible to form fine through holes 115 with high shape accuracy.

[0108] The laser can be an excimer laser, a carbon dioxide gas laser, a YAG laser, or the like, which can accurately drill holes in resin. Among them, it is preferable to use an excimer laser. The pulse width of the laser is not particularly limited, and may be any of a microsecond laser, a nanosecond laser, a picosecond laser, and a femtosecond laser. The wavelength of the laser is also not particularly limited.

[0109] Regarding step 3) Next, one continuous conductive layer 151 is formed in each region of the laminated sheet 150 where the multiple through holes 115 are formed (see FIG. 4C). Specifically, the conductive layer 151 is formed continuously on the inner wall surfaces of the multiple through holes 115 of the laminated sheet 150 and on the first surface 150a and the second surface 150b around the openings.

[0110] The conductive layer 151 can be formed by any method. Since the conductive layer 151 can be formed thin and with a uniform thickness without blocking the through-hole 115, it is preferable to form the conductive layer 151 by a plating method (for example, an electroless plating method or an electrolytic plating method).

[0111] 4) About the process Next, the inside of the plurality of cavities 115' surrounded by the conductive layer 151 is filled with a conductive rubber composition L (see FIG. 4D).

[0112] The conductive rubber composition L can be filled by, for example, applying the conductive rubber composition L onto the first surface 150a and drawing a vacuum inside the cavity 115' from the second surface 150b side. Then, the filled conductive rubber composition L is crosslinked.

[0113] 5) About the process Next, a plurality of first grooves 116a and a plurality of second grooves 116b are formed on the first surface 150a and the second surface 150b of the laminated sheet 150, respectively (see FIGS. 4E and 4F). As a result, the portion of the conductive layer 151 on the first surface 150a side is divided into a plurality of first conductive layers 122A, and the portion of the conductive layer 151 on the second surface 150b side is divided into a plurality of second conductive layers 122B. Furthermore, in this embodiment, the first surface resin layer 112A is divided into a plurality of first surface resin layers 112A, and the second surface resin layer 112B is divided into a plurality of second surface resin layers 112B. The formation of the first grooves 116a and the second grooves 116b can be performed, for example, by a laser processing method. As a result, an anisotropic conductive sheet 100 can be obtained having an electrode region in which a plurality of conductive layers 120 and a plurality of conductive fillers 130 are formed on the insulating layer 110 .

[0114] The method for producing the anisotropic conductive sheet 100 may further include other steps than those described above, as necessary. For example, a pretreatment may be performed between steps 2) and 3) to facilitate the formation of the conductive layer 151.

[0115] For example, it is preferable to perform a desmear treatment (pretreatment) on the laminated sheet 150 having a plurality of through holes 115 formed therein in order to facilitate the formation of the conductive layer 151. The desmear treatment can be performed by a wet method or a dry method, and either method may be used.

[0116] As the wet desmear treatment, in addition to alkali treatment, known wet processes such as a sulfuric acid method, a chromic acid method, a permanganate method, etc. can be used.

[0117] An example of the desmear treatment by the dry method is plasma treatment. For example, when the laminated sheet 150 is made of a cross-linked product of a silicone rubber composition, the sheet can be subjected to plasma treatment to not only perform ashing / etching but also oxidize the surface of the silicone to form a silica film. Forming a silica film can facilitate the infiltration of the plating solution into the through-hole 115 and can increase the adhesion between the conductive portion 121 and the inner wall surface of the through-hole 115. The oxygen plasma treatment can be performed using, for example, a plasma asher, a high-frequency plasma etching device, or a microwave plasma etching device.

[0118] The anisotropic conductive sheet 100 may be cut to a predetermined size and fixed to the frame 200.

[0119] 3. Anisotropic conductive sheet with frame Fig. 6A is a schematic plan view of the framed anisotropic conductive sheet 400, and Fig. 6B is a schematic enlarged cross-sectional view of the framed anisotropic conductive sheet 400 taken along line 6B-6B in Fig. 6A. Note that hatching of the cross section is omitted in Fig. 6B.

[0120] As shown in FIGS. 6A and 6B, in this embodiment, a framed anisotropic conductive sheet 400 has a frame 200, two anisotropic conductive sheets 100P, and two sealing materials 300.

[0121] The frame 200 has two openings 210 through which the anisotropic conductive sheet 100P is inserted, and four positioning holes 220 (see FIG. 6B). The material constituting the frame 200 is preferably a material having a higher strength than the material constituting the elastomer layer 111 of the anisotropic conductive sheet 100P. Such materials include metal, glass, ceramics, heat-resistant resin, etc., and are preferably metal such as stainless steel (SUS). When the frame 200 is made of metal, an insulating layer or the like is disposed on a second surface 200b of the frame 200 opposite to the first surface 200a.

[0122] The thickness of the frame 200 is smaller than the thickness of the anisotropic conductive sheet 100P. This allows the anisotropic conductive sheet 100P to protrude from at least the first surface 200a of the frame 200.

[0123] The openings 210 are through holes provided in the frame 200, into which the anisotropic conductive sheet 100P is inserted. In this embodiment, the number of openings 210 is two, but it may be one, or three or more (see FIG. 6A). The size of the openings 210 only needs to be large enough to allow the anisotropic conductive sheet 100P to be inserted, and is preferably equal to or slightly larger than the size of the anisotropic conductive sheet 100P.

[0124] The anisotropic conductive sheet 100P is cut out from the above-mentioned anisotropic conductive sheet 100. In this embodiment, the anisotropic conductive sheet 100 protrudes from at least the first surface 200a of the frame 200 when inserted into the opening 210 of the frame 200 (see FIG. 6B). An object to be inspected is placed on the surface of the anisotropic conductive sheet 100P protruding from the first surface 200a of the frame 200.

[0125] In this embodiment, the first surface 110a side of the insulating layer 110 has a larger protruding length than the second surface 110b side. The protruding length Ha of the anisotropic conductive sheet 100P from the first surface 200a of the frame 200 is not particularly limited, but is, for example, 100 μm or more, and preferably 150 to 400 μm. The protruding length Hb of the anisotropic conductive sheet 100P from the second surface 200b of the frame 200 is not particularly limited, but is, for example, 30 to 40 μm. This allows the terminals of the test object and the electrodes of the test board to be more reliably electrically connected via the anisotropic conductive sheet 100P.

[0126] The anisotropic conductive sheet 100P is usually rectangular in shape in plan view. The size of the anisotropic conductive sheet 100P in plan view can be, for example, 1 to 30 mm in the X direction (long side) and 1 to 30 mm in the Y direction (short side).

[0127] A sealing material 300 is used to bond between the first surface 200a of the frame 200 and the anisotropic conductive sheet 100P protruding from the first surface 200a.

[0128] The sealing material 300 preferably has affinity with the material constituting the elastomer layer 111 of the anisotropic conductive sheet 100P. Therefore, the sealing material 300 preferably contains a cross-linked product of a rubber composition. The type of rubber component contained in the sealing material 300 may be the same as the rubber component contained in the elastomer layer 111. The type of rubber component contained in the sealing material 300 may be the same as or different from the rubber component contained in the elastomer layer 111. Among them, silicone rubber is preferable.

[0129] The anisotropic conductive sheet 400 with the frame is obtained by cutting the anisotropic conductive sheet 100 (original sheet) to a size that fits the opening 210 of the frame 200 to obtain the anisotropic conductive sheet 100P. This is inserted into the opening 210 of the frame 200, and a sealing material 300 is formed between the first surface 200a of the frame 200, thereby obtaining the anisotropic conductive sheet 400 with the frame.

[0130] 4. Electrical inspection equipment and electrical inspection method 7 is a schematic cross-sectional view of an electrical inspection device 500 according to this embodiment, in which the dimensions of the main parts in the thickness direction are shown relatively large.

[0131] Electrical inspection device 500 is a device that inspects electrical characteristics (such as continuity) between terminals 521 (between measurement points) of an object under inspection 520. Note that in this figure, object under inspection 520 is also shown in order to explain the electrical inspection method.

[0132] As shown in FIG. 7, an electrical inspection device 500 has a substrate 510 (test board) having a plurality of electrodes, and an anisotropic conductive sheet 400 with a frame.

[0133] The substrate 510 has, on its surface facing the test object 520 , a plurality of electrodes 511 facing each measurement point of the test object 520 .

[0134] The framed anisotropic conductive sheet 400 is placed on the substrate 510 by inserting the positioning pins 512 of the substrate 510 into the positioning holes 220. This brings the electrodes 511 of the substrate 510 into contact with the second conductive layer 122B (not shown) of the anisotropic conductive sheet 100P.

[0135] Then, the inspection object 520 is placed on the anisotropic conductive sheet 100P of the framed anisotropic conductive sheet 400. Specifically, the inspection object 520 is placed on the first surface 110a side of the insulating layer 110 of the anisotropic conductive sheet 100P.

[0136] The inspection object 520 is not particularly limited, and examples thereof include various semiconductor devices (semiconductor packages) such as HBM and PoP, electronic components, and printed circuit boards. When the inspection object 520 is a semiconductor package, the measurement points may be bumps (terminals). When the inspection object 520 is a printed circuit board, the measurement points may be measurement lands or component mounting lands provided on a conductive pattern. The inspection object 520 includes, for example, a chip having a total of 264 solder ball electrodes (material: lead-free solder) with a diameter of 0.2 mm and a height of 0.17 mm, arranged at a pitch of 0.3 mm.

[0137] Next, an electrical inspection method using electrical inspection device 500 will be described.

[0138] 7, in the electrical inspection method according to the present embodiment, a substrate 510 having electrodes 511 and an object to be inspected 520 are laminated via an anisotropic conductive sheet 100P fixed by a frame 200. As a result, the electrodes 511 of the substrate 510 and the terminals 521 of the object to be inspected 520 are electrically connected via the anisotropic conductive sheet 100P.

[0139] When carrying out the above process, in order to facilitate sufficient electrical continuity between the electrodes 511 of the substrate 510 and the terminals 521 of the object to be inspected 520 via the anisotropic conductive sheet 100P, the object to be inspected 520 may be pressed to apply pressure or brought into contact under a heated atmosphere, if necessary.

[0140] In this embodiment, the anisotropic conductive sheet 100P has a second elastomer layer 111B that is lower in hardness than the first elastomer layer 111A. Therefore, the indentation load can be dispersed to the second elastomer layer 111B, and the load can be prevented from concentrating on the first elastomer layer 111A. This can reduce the amount of distortion of the first elastomer layer 111A, and therefore can prevent an increase in electrical resistance caused by cracks or breakage in the conductive layer 120.

[0141] 5. Variations In the anisotropic conductive sheet 100 according to the above embodiment, the insulating layer 110 has two elastomer layers (first elastomer layer 111A, second elastomer layer 111B), but is not limited thereto and may have three or more elastomer layers. In that case, it is sufficient that the hardness of at least one elastomer layer on the first surface side among the three or more elastomer layers is higher than the hardness of at least one elastomer layer on the second surface side.

[0142] 8A to 8C are schematic partially enlarged cross-sectional views showing a method for manufacturing an anisotropic conductive sheet according to a modified example. 8A, the insulating layer 110 may further include a third elastomer layer 111C disposed on the opposite side of the second elastomer layer 111B from the first elastomer layer 111A. The hardness of the second elastomer layer 111B is lower than the hardness of the third elastomer layer 111C. The third elastomer layer 111C may be configured in the same manner as or similar to the first elastomer layer 111A. The composition and physical properties of the third elastomer layer 111C may be different from the composition and physical properties of the first elastomer layer 111A. For example, the hardness and thickness of the third elastomer layer 111C may be different from the hardness and thickness of the first elastomer layer 111A.

[0143] 8B, insulating layer 110 may further include intermediate resin layer 113 disposed between second elastomer layer 111B and third elastomer layer 111C. Intermediate resin layer 113 disposed between second elastomer layer 111B and third elastomer layer 111C may be configured in the same manner as intermediate resin layer 113 disposed between second elastomer layer 111B and first elastomer layer 111A. The two intermediate resin layers 113, 113 may have different compositions and physical properties.

[0144] 8C, insulating layer 110 may not include intermediate resin layer 113, and may instead have first elastomer layer 111A, second elastomer layer 111B, and third elastomer layer 111C laminated directly in this order.

[0145] In this way, when insulating layer 110 includes three or more elastomer layers, it is preferable that the total thickness Z1 of the elastomer layer having the highest hardness is smaller than the total thickness Z2 of the other elastomer layers. Specifically, it is preferable that the ratio (Z2 / Z1) of the total thickness Z1 of the elastomer layer having the highest hardness to the total thickness Z2 of the other elastomer layers is 1.5 to 5. For example, in Figures 8A and 8B, when the first elastomer layer 111A and the third elastomer layer 111C have the same hardness, it is preferable that the ratio (Z2 / Z1) of their total thickness Z1 to the thickness Z2 of the second elastomer layer 111B other than them is within the above range.

[0146] In addition, in the anisotropic conductive sheet 100 according to the above embodiment, the insulating layer 110 has a plurality of first surface resin layers 112A, a plurality of second surface resin layers 112B and an intermediate resin layer 113, but is not limited to this and may not have some or all of these depending on the required handling properties and dimensional stability.

[0147] In addition, in the anisotropic conductive sheet 100 according to the above embodiment, the insulating layer 110 has four primer layers 114, but depending on the degree of adhesion between the layers, some or all of these primer layers 114 may be omitted.

[0148] In the anisotropic conductive sheet 100 according to the above embodiment, the inside of the through hole 115 is filled with the conductive filler 130, but this is not limited thereto and the through hole 115 may not be filled. In addition, the conductive layer 120 has the first conductive layer 122A and the second conductive layer 122B, but this is not limited thereto and the first conductive layer 122A and the second conductive layer 122B may not be included depending on the desired level of conductivity. EXAMPLES

[0149] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these.

[0150] [Example 1] (1) Preparation of laminated sheet A laminated sheet (total thickness 347.5 μm) having a laminated structure of polyimide resin layer / silicone-based elastomer layer A (hardness 50) / polyimide resin layer / silicone-based elastomer layer B (hardness 20) / polyimide resin layer (7.5 μm / 110 μm / 12.5 μm / 210 μm / 7.5 μm) was prepared by the following procedure.

[0151] (1-1) Preparation of surface sheet S1-A A solution containing a metal alkoxide (Primer No. 4, manufactured by Shin-Etsu Silicones) was applied to one side of a polyimide film (thickness 7.5 μm, Kapton 30 (registered trademark), Tg>300°C, storage modulus at 25°C 5 GPa) (first outer resin layer 112A) and dried to form a primer layer (primer layer 114, thickness 0.7 μm). Next, a two-liquid additive liquid silicone rubber composition was applied onto the primer layer, and then a commercially available silicone rubber sheet (Sirius manufactured by Fuso Rubber Co., Ltd., thickness 110 μm, hardness 50, storage modulus at 25° C. 3.5 MPa) was laminated under normal pressure and heated on a hot plate at 50° C. for 10 minutes to bond, forming a silicone-based elastomer layer A (first elastomer layer 111A). Prior to lamination, the surfaces to be laminated were irradiated with plasma at 800 W, 0.5 L / min, and 1 minute. Thereby, a surface sheet S1-A having a laminated structure of polyimide film / primer layer / silicone-based elastomer layer A (first elastomer layer 111A) was prepared.

[0152] (1-2) Preparation of surface sheet S1-B In producing the surface sheet S1-A, a surface sheet S1-B having a laminated structure of polyimide film / primer layer / silicone-based elastomer layer B (second elastomer layer 111B) was prepared in the same manner as the surface sheet S1-A, except that a commercially available silicone rubber sheet (Sirius manufactured by Fuso Rubber Co., Ltd., thickness 210 μm, hardness 20, storage modulus at 25°C 0.8 MPa) was used instead of the above silicone rubber sheet.

[0153] (1-3) Preparation of intermediate sheet S2 A primer layer (primer layer 114) having a thickness of 0.7 μm was formed on both sides of a polyimide film (thickness 12.5 μm, Kapton 50EN (registered trademark) manufactured by Toray DuPont, Tg > 300°C, storage modulus at 25°C 5 GPa) (intermediate resin layer 113) in the same manner as described above. Next, a two-part additive liquid silicone rubber composition was further applied onto the primer layer and cured to form an adhesive layer (thickness: 5 μm). As a result, an intermediate sheet S2 having a laminated structure of adhesive layer / primer layer / polyimide film / primer layer / adhesive layer was obtained.

[0154] (1-4) Preparation of laminated sheet The adhesive layer of the intermediate sheet S2, the silicone elastomer layer A of the top sheet S1-A, and the silicone elastomer layer B of the top sheet S2-B were each irradiated with plasma under the same conditions as above. Then, the plasma-irradiated surface of the adhesive layer of the intermediate sheet S2 and the plasma-irradiated silicone elastomer layers A and B of the two surface sheets S1-A and S1-B were attached to each other under normal pressure (see FIG. 5A), and heated on a hot plate at 50° C. for 10 minutes to bond them together. This resulted in a laminated sheet having the above-mentioned laminated structure (see FIG. 5B).

[0155] (1-5) Measurement methods for physical properties The hardness of the silicone-based elastomer layers A and B was a value measured with a durometer (type A) in accordance with ASTM D 2240 (JIS K 6253-2012). The storage modulus was measured in accordance with JIS K 7244-1: 1998 / ISO6721-1: 1994. The Tg of the polyimide film was measured in accordance with JIS K 7095: 2012, and although no clear glass transition temperature was observed, it was determined to be 300°C or higher because it showed a viscoelastic change at 300°C or higher.

[0156] (2) Preparation of anisotropic conductive sheet A plurality of through holes 115 (the openings of the plurality of through holes 115 on the first surface 150a side have a circle equivalent diameter of 100 μm) were formed in the stacking direction (thickness direction) of the obtained laminated sheet, and then a continuous gold (Au) layer (conductive layer 151) was formed by plating on the surface of the laminated sheet (the inner wall surfaces of the through holes 115, the first surface 150a and the second surface 150b). Next, on the first surface 150a of the obtained sheet, ThreeBond 3303B (containing Ag particles, silicone rubber, and a crosslinking agent, the volume resistivity of the crosslinked product according to ASTM D 991 is 3×10) manufactured by ThreeBond Co., Ltd. was applied as a conductive elastomer composition. ―5 The composition was introduced and filled into cavity 115' corresponding to through hole 115 while drawing a vacuum from the second surface 150b side, and was then heated at 170°C to cause crosslinking. Next, a plurality of first grooves 116a and second grooves 116b were formed in a lattice pattern on the first surface 150a and second surface 150b of the obtained sheet by laser processing. As a result, the first surface resin layer 112A was divided into a plurality of first surface resin layers 113A, and the second surface resin layer 112B was divided into a plurality of second surface resin layers 113B. In addition, the conductive layer 151 was divided into a plurality of first conductive layers 122A and a plurality of second conductive layers 122B. Next, the peripheral portions of the first conductive layer 122A and the second conductive layer 122B were further removed by laser processing to obtain the anisotropic conductive sheet 100. As a result, an anisotropic conductive sheet 100 (total thickness 347.5 μm) having a laminated structure of polyimide resin layer / silicone-based elastomer layer A (hardness 50) / polyimide resin layer / silicone-based elastomer layer B (hardness 20) / polyimide resin layer (7.5 μm / 110 μm / 12.5 μm / 210 μm / 7.5 μm) was obtained (see FIGS. 2A and 2B). The distance between the centers of gravity of the multiple first conductive layers 122A was 300 μm.

[0157] [Comparative Example 1] An anisotropic conductive sheet was produced in the same manner as in Example 1, except that the silicone-based elastomer layer B was changed to a silicone-based elastomer layer A, i.e., a laminate sheet (total thickness 347.5 μm) having a laminate structure of polyimide resin layer / silicone-based elastomer layer A (hardness 50) / polyimide resin layer / silicone-based elastomer layer A (hardness 50) / polyimide resin layer (7.5 μm / 110 μm / 12.5 μm / 210 μm / 7.5 μm) was used.

[0158] [evaluation] For the anisotropically conductive sheet thus obtained, the average resistance value was measured by the following method when the indentation load was changed.

[0159] (Pressure test) The obtained anisotropically conductive sheet 100 was cut into a size of 10 × 20 mm by a femtosecond laser to obtain an anisotropically conductive sheet 100 P. This was fixed to a frame as shown in Figures 6A and 6B to obtain a framed anisotropically conductive sheet 400. 9A, the anisotropic conductive sheet 100 was positioned on the testing board 310 by inserting the positioning pins 512 of the testing board 510 into the positioning holes (not shown) of the framed anisotropic conductive sheet 400. A test chip 520 was placed on the anisotropic conductive sheet 100P as an object to be tested, and these were fixed with a pressing jig.

[0160] The test chip 520 used had a total of 264 solder ball electrodes (material: lead-free solder) with a diameter of 0.2 mm and a height of 0.17 mm, arranged at a pitch of 0.3 mm, with two of these solder ball electrodes electrically connected to each other by wiring within the test chip 520 (see Figure 9B).

[0161] Next, at 25° C., the load applied to the test chip 520 by the pressure jig was gradually changed (increased) and the electrical resistance value was measured at each load.

[0162] (Measurement of electrical resistance) The electrical resistance value was measured by the following method. A direct current of 10 mA was constantly applied between the external terminals (not shown) of the testing board 510, which were electrically connected to each other via the anisotropic conductive sheet 100P, the test chip 520, and the electrodes 511 (test electrodes) of the testing board 510 and their wiring (not shown), by a direct current power source 530 and a constant current control device 531, and the voltage between the external terminals of the testing board 510 when pressure was applied was measured by a voltmeter 332. The measured voltage value (V) was V1, and the applied direct current was I1 (=10 mA), and the electrical resistance value R1 was calculated by the following formula.

number

[0163] (Cycle test) In the electrical resistance measurement, a cycle of pressurization / depressurization of the test chip 520 was repeated under a load of 10 kg, and the number of cycles until the average resistance reached 100 mΩ was measured. In addition, the appearance of the electrode after the cycle test was observed.

[0164] The evaluation results are shown in Table 1. [Table 1]

[0165] As shown in Table 1, the anisotropic conductive sheet of Comparative Example 1, in which the hardness of the second elastomer layer on the second surface side and the hardness of the first elastomer layer on the first surface side were made the same, required 10,000 cycles for the average resistance to reach 100 mΩ. Furthermore, when the appearance of the electrode after the cycle test was observed, many cracks were confirmed in the conductive layer near the surface layer on the first surface side.

[0166] In contrast, the anisotropic conductive sheet of Example 1, in which the hardness of the second elastomer layer on the second surface side was lower than that of the first elastomer layer on the first surface side, required more than 50,000 cycles for the average resistance to reach 100 mΩ. Also, the conductive layer near the surface layer on the first surface side had significantly fewer cracks.

[0167] From these findings, it can be seen that by making the hardness of the second elastomer layer on the second surface side lower than the hardness of the first elastomer layer on the first surface side, cracks and other defects in the conductive layer near the surface on the first surface side can be suppressed, and an increase in electrical resistance can be suppressed. [Industrial Applicability]

[0168] According to the present invention, it is possible to provide an anisotropic conductive sheet in which the conductive layer is less susceptible to breakage and the like even when repeatedly subjected to a pressing load, and in which the electrical resistance value is less likely to increase. [Explanation of symbols]

[0169] 100 Anisotropic conductive sheet 100P (individually cut) anisotropic conductive sheet 110 Insulating layer 110a (insulating layer) first surface 110b (insulating layer) second surface 111A First Elastomer Layer 111B Second elastomer layer 111C Third elastomer layer 112A 1st surface resin layer 112B 2nd surface resin layer 113 Intermediate resin layer 114 Primer layer 115 Through hole 115' hollow 116a 1st groove 116b 2nd groove 120 Conductive layer 121 Conductive part 122A 1st conductive layer 122B Second conductive layer 130 Conductive filling 140a 1st exposed part 140b 2nd exposed part 150 Laminated Sheet 151 Conductive layer 200 frames 200a (frame) first surface 200b (frame) second surface 201 Base material layer 202 Frame insulation layer 210 Opening 300 Sealant 400 Anisotropic conductive sheet with frame 500 Electrical Testing Equipment 510 Substrate 511 Electrode 512 Locating pin 520 Inspection object 521 Terminal

Claims

1. an insulating layer having a first surface on one side in a thickness direction, a second surface on the other side, and a plurality of through holes penetrating from the first surface to the second surface; A plurality of conductive portions disposed on inner wall surfaces of the plurality of through holes; a plurality of first conductive layers disposed on the first surface of the insulating layer and connected to one or more of the conductive portions; a plurality of second conductive layers disposed on the second surface of the insulating layer and connected to one or more of the conductive portions; Including, The insulating layer is A first elastomeric layer; and a second elastomer layer disposed on the second surface side of the first elastomer layer; Including, The hardness of the second elastomer layer is lower than the hardness of the first elastomer layer. Anisotropic conductive sheet.

2. a third elastomer layer disposed on the opposite side of the second elastomer layer from the first elastomer layer, The hardness of the second elastomer layer is lower than the hardness of the third elastomer layer. The anisotropic conductive sheet according to claim 1 .

3. An object to be inspected is placed on the first surface side.

3. The anisotropic conductive sheet according to claim 1 or 2.

4. The hardness of the first elastomer layer is 50 or more.

3. The anisotropic conductive sheet according to claim 1 or 2.

5. The hardness of the second elastomer layer is 10 or more and less than 50.

3. The anisotropic conductive sheet according to claim 1 or 2.

6. The difference between the hardness of the first elastomer layer and the hardness of the second elastomer layer is 10 or more.

3. The anisotropic conductive sheet according to claim 1 or 2.

7. The thickness of the second elastomer layer is greater than the thickness of the first elastomer layer.

3. The anisotropic conductive sheet according to claim 1 or 2.

8. A ratio T2 / T1 of a thickness T2 of the second elastomer layer to a thickness T1 of the first elastomer layer is 1.5 to 5. The anisotropic conductive sheet according to claim 1 .

9. a ratio Z2 / Z1 of a total thickness Z2 of the elastomer layers other than the elastomer layer having the highest hardness to a total thickness Z1 of the elastomer layer having the highest hardness among the elastomer layers included in the insulating layer is 1.5 to 5; The anisotropic conductive sheet according to claim 2 .

10. the first elastomer layer and the second elastomer layer each contain a cross-linked product of a silicone rubber composition; 3. The anisotropic conductive sheet according to claim 1 or 2.

11. The insulating layer is one or more first surface resin layers arranged on a surface of the first elastomer layer opposite to the second elastomer layer and constituting the first surface; one or more second surface resin layers arranged on a surface of the second elastomer layer opposite to the first elastomer layer and constituting the second surface; and The storage modulus at 25° C. of the one or more first surface resin layers and the one or more second surface resin layers is higher than the storage modulus at 25° C. of the first elastomer layer and the second elastomer layer.

3. The anisotropic conductive sheet according to claim 1 or 2.

12. The insulating layer is an intermediate resin layer disposed between the first elastomer layer and the second elastomer layer; The storage modulus at 25°C of the intermediate resin layer is higher than the storage modulus at 25°C of the first elastomer layer and the second elastomer layer. The anisotropic conductive sheet according to claim 11.

13. The one or more first surface resin layers are a plurality of first surface resin layers, The one or more second surface resin layers are a plurality of second surface resin layers, the first conductive layers are disposed on the first outer resin layers, The plurality of second conductive layers are respectively disposed on the plurality of second surface resin layers. The anisotropic conductive sheet according to claim 11.

14. A testing substrate having a plurality of electrodes; The anisotropic conductive sheet according to claim 1 , which is disposed on a surface of the testing board on which the plurality of electrodes are disposed; having The inspection object is placed on the first surface side. Electrical testing equipment.

15. a step of laminating a testing board having a plurality of electrodes and a test object having terminals via the anisotropic conductive sheet according to claim 1, and electrically connecting the electrodes of the testing board and the terminals of the test object via the anisotropic conductive sheet, The inspection object is placed on the first surface side. Electrical testing methods.

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