Anisotropic conductive connector

Abstract

To provide an anisotropic conductive connector capable of reducing distortion remaining in a base layer and a conductive thin wire even if compression and release are repeated, and suppressing distortion of the conductive thin wire following the movement of the base layer.SOLUTION: The anisotropic conductive connector 10 includes a base layer 11 interposed between a wiring board 1 for inspection and a BGA3, and a plurality of bendable metallic thin wires 12 incorporated in the base layer 11 and having both upper and lower ends exposed, wherein the ends of the plurality of metallic thin wires 12 come into conductive contact with electrodes of the wiring board 1 for inspection or solder balls 4 of the BGA3. The base layer 11 is formed into a rubber sheet by primary vulcanization and secondary vulcanization of a molding material containing silicone rubber excellent in at least impact resilience and durability, and the Shore A hardness before the secondary vulcanization measured according to JIS K6235 of the base layer 11 is set to ≥ 52 ° H and ≤ 59 ° H, and the Shore A hardness after the secondary vulcanization measured according to JIS K6235 of the base layer 11 is set to ≥ 65 ° H and ≤ 71 ° H.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an anisotropic conductive connector used for inspecting and connecting various wiring boards and semiconductor packages. [Background technology]

[0002] A surface-mount semiconductor package, such as a BGA 3 shown in FIG. 8 with multiple solder balls, excels in high mounting density and electrical properties, but has the disadvantage of being difficult to test. In view of this, an anisotropic conductive connector 10 shown in FIG. 8 has been used in conventional BGA 3 testing (see Patent Document 1). This anisotropic conductive connector 10 includes a base layer 11 interposed between a lower wiring board 1 for testing and an upper BGA 3, and multiple thin metal wires 12 embedded in the base layer 11 with both upper and lower ends exposed. These multiple thin metal wires 12 electrically connect the electrodes of the wiring board 1 for testing and the solder balls 4 of the BGA 3.

[0003] The wiring board for testing 1 is made of, for example, a printed wiring board on which an anisotropic conductive connector 10 is mounted, and a guide frame 2 that is approximately frame-shaped in plan view and has an inverted L-shaped cross section and surrounds the anisotropic conductive connector 10 is attached to the surface, and a BGA 3 to be mounted on the anisotropic conductive connector 10 is detachably positioned and fitted into the opening of this guide frame 2. The BGA 3 has a package that is approximately rectangular in plan view, and a plurality of solder balls 4 that serve as electrodes are arranged at predetermined intervals in the X and Y directions on the lower surface of the lower part of this package.

[0004] The base layer 11 of the anisotropic conductive connector 10 is formed from an elastically deformable flat rectangular rubber sheet. A plurality of thin metal wires 12 are arranged at predetermined intervals in the X and Y directions of the base layer 11 and are oriented at a predetermined angle (e.g., 0° to 60°) in the thickness direction of the base layer 11. Each thin metal wire 12 is made of a bendable pure gold wire, gold alloy wire, gold-plated wire, gold-plated brass wire, solder-plated wire, copper alloy wire, or the like having a diameter of 90 μm or less.

[0005] In order to avoid contact between the metal fine wires 12, both ends of the metal fine wires 12 protrude slightly from both the front and back sides of the base layer 11, preferably by a length of 10 μm or more and 20 μm or less, with the lower end making direct contact with the electrode of the testing wiring board 1 so as to be conductive, and the upper end making direct contact with the solder ball 4 of the BGA 3 so as to be conductive.

[0006] In the above configuration, when inspecting a BGA 3, the BGA 3 is positioned and fitted into the opening of the guide frame 2 to be mounted on the anisotropic conductive connector 10, the solder balls 4 of the BGA 3 are brought into contact with the ends of the fine metal wires 12, and then the BGA 3 is pressed down. This compresses the base layer 11 of the anisotropic conductive connector 10, electrically connecting the wiring board for inspection 1, the fine metal wires 12, and the BGA 3, allowing the BGA 3 to be inspected. Once inspection of the BGA 3 is complete, the BGA 3 is released from the press and removed from the guide frame 2, completing the BGA 3 inspection process. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 11-211754 Summary of the Invention [Problem to be solved by the invention]

[0008] The conventional anisotropic conductive connector 10 is configured as described above, and because the base layer 11 is simply formed from an elastically deformable rubber sheet, repeated compression and release causes a problem in that distortion remains in the base layer 11 and the plurality of thin metal wires 12. Furthermore, if the material of the thin metal wires 12 is flexible, the thin metal wires 12 will follow the movement of the base layer 11 and become distorted, which may make it impossible to maintain the connection between the electrodes of the wiring board 1 for testing and the solder balls 4 of the BGA 3.

[0009] The present invention has been made in consideration of the above, and aims to provide an anisotropic conductive connector that reduces residual distortion in the base layer and conductive wires even when compression and release are repeated, and that can prevent the conductive wires from being distorted due to movement of the base layer. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, the present invention provides a conductive element including a base layer interposed between a plurality of electrical connecting objects, and a plurality of bendable thin conductive wires embedded in the base layer and having both ends exposed, the ends of the plurality of thin conductive wires being in conductive contact with the electrical connecting objects, The base layer is formed into a rubber sheet by primary and secondary vulcanization of a molding material containing silicone rubber, which has excellent impact resilience and durability, and is characterized by a Shore A hardness of 52°H or more and 59°H or less before secondary vulcanization, measured in accordance with JIS K 6253, and a Shore A hardness of 65°H or more and 71°H or less after secondary vulcanization, measured in accordance with JIS K 6253.

[0011] The base layer can be sandwiched between the wiring board and the surface-mount semiconductor package. The molding material may contain 0.4 to 0.6 parts by mass of a catalyst and 4.9 to 5.1 parts by mass of a crosslinking agent per 100 parts by mass of insulating silicone rubber. Furthermore, the base layer preferably has a median compression set of 1.6% or more and 1.9% or less, measured multiple times in accordance with JIS K 6262.

[0012] Furthermore, when the base layer is subjected to repeated 10 compression load displacement measurements, the load difference between the compression load and the return load at the first measurement is preferably 635N or more and 655N or less, and the load difference at the tenth measurement is preferably 299N or more and 319N or less. Furthermore, when the base layer is subjected to 10 repeated compression load displacement measurements, the difference in peak load between the first and tenth repeated compressions is preferably 182 N or more and 202 N or less.

[0013] Here, the electrical junctions in the claims include at least printed wiring boards, various wiring boards made of high-density flexible substrates, semiconductor packages such as DIP and QFP, etc. Furthermore, surface-mount semiconductor packages include at least BGA, LGA, and PGA. Each numerical value may include measurement error and other different numerical values ​​as long as there is no difference in the effects of the present invention.

[0014] The up / down, front / rear, left / right directions of the anisotropic conductive connector according to the present invention are directions based on the drawings and can be appropriately changed as needed. Furthermore, although the subject of the present invention is an anisotropic conductive connector, if the configuration of another application is the same as the configuration of the present invention and can be converted into an anisotropic conductive connector, and the effects of the present invention are achieved, the configuration of the other application falls within the technical scope of the present invention.

[0015] According to the present invention, the base layer of the anisotropic conductive connector is formed on a rubber sheet using silicone rubber, which has excellent impact resilience and durability, so that the base layer is less susceptible to compression deformation, and the base layer can be compressed multiple times with approximately the same load or amount of compression. Furthermore, even if the conductive thin wires are made of a flexible material, the conductive thin wires, which have low spring properties, can follow the movement of the base layer and easily restore their original shape. [Effects of the Invention]

[0016] According to the present invention, even if compression and release are repeated, residual distortion in the base layer and conductive fine wires of the anisotropic conductive connector can be reduced, and distortion of the conductive fine wires due to movement of the base layer can be suppressed. According to the invention of claim 2, it is possible to easily inspect a surface mount type semiconductor package, which contributes to facilitating mounting and the like.

[0017] According to the invention described in claim 3, the median value of the compression set of the base layer measured multiple times in accordance with JIS K 6262 is 1.6% or more and 1.9% or less, thereby reducing residual distortion in the base layer.

[0018] According to the invention described in claim 4, when the compressive load displacement of the base layer is measured repeatedly 10 times, the load difference between the compressive load and the return load for the first time is 635N or more and 655N or less, and the load difference for the tenth time is 299N or more and 319N or less, making it possible to make the base layer less susceptible to compressive deformation. According to the invention described in claim 5, when the compressive load displacement of the base layer is measured after 10 repeated compressions, the peak load difference between the first and tenth repeated compressions is 182 N or more and 202 N or less, so that improved durability of the base layer can be expected. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a graph showing the rubber properties when a compressive load is repeatedly applied 10 times to a test piece in an example of an anisotropically conductive connector according to the present invention. [Figure 2] 10 is a graph showing the load difference between the peak loads of the first and tenth repeated compressions in an example of an anisotropically conductive connector according to the present invention. [Figure 3] 10 is a graph showing load characteristics in an example of an anisotropic conductive connector according to the present invention. [Figure 4] 10 is a graph showing the relationship between load and resistance value in an example of an anisotropic conductive connector according to the present invention. [Figure 5] 10 is a graph showing the rubber properties when a compressive load is repeatedly applied 10 times to a test piece in a comparative example of an anisotropically conductive connector according to the present invention. [Figure 6] 10 is a graph showing load characteristics in a comparative example of an anisotropic conductive connector according to the present invention. [Figure 7] 10 is a graph showing the relationship between load and resistance value in a comparative example of an anisotropic conductive connector according to the present invention. [Figure 8] 10 is a partial cross-sectional explanatory view schematically showing an inspection state of a BGA using an anisotropic conductive connector. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] A preferred embodiment of the present invention will now be described with reference to the drawings. As shown in FIG. 8, the anisotropic conductive connector 10 in this embodiment comprises a compressible and deformable base layer 11 interposed between a lower inspection wiring board 1 and an upper BGA 3, and a plurality of bendable thin metal wires 12 embedded in this base layer 11 with both upper and lower ends exposed, and the ends of the plurality of thin metal wires 12 are in close contact with electrodes of the inspection wiring board 1 or solder balls 4 of the BGA 3 so as to be conductive. The base layer 11 is formed into a rubber sheet by primary vulcanization and secondary vulcanization of silicone rubber, which has at least excellent resilience and durability, thereby contributing to the achievement of Goal 9 of the SDGs adopted at the United Nations Summit.

[0021] The wiring board for testing 1 and BGA 3 have the same configuration as in the conventional example, and therefore a description thereof will be omitted. The silicone rubber sheet of the base layer 11 is produced by first vulcanizing (molding) a rubber sheet using a molding material containing silicone rubber, which has superior rebound resilience, durability, flexibility, insulation, heat resistance, weather resistance, flame retardancy, etc. compared to general silicone rubber, and then by second vulcanizing the rubber sheet to remove low-molecular-weight siloxane and stabilize physical properties.

[0022] The molding material contains a paste-type silicone rubber, which is excellent in elasticity and durability. In addition to this paste-type silicone rubber, the molding material also contains a room-temperature curing catalyst that functions as a vulcanizing agent and a crosslinking agent that functions as a regulator to improve rubber hardness. The catalyst, for example, is an addition-type C-19A (product name, manufactured by Shin-Etsu Chemical Co., Ltd.), and is added in an amount of 0.4 to 0.6 parts by mass, preferably 0.5 parts by mass, per 100 parts by mass of silicone rubber. In contrast, the crosslinking agent, for example, is an addition-type C-19B (product name, manufactured by Shin-Etsu Chemical Co., Ltd.), and is added in an amount of 4.9 to 5.1 parts by mass, preferably 5 parts by mass, per 100 parts by mass of silicone rubber, which is higher than conventional amounts. This crosslinking agent functions to improve rubber hardness after secondary vulcanization.

[0023] The primary vulcanization of the silicone rubber sheet is carried out by hot press molding for 10 to 15 minutes at a high temperature of, for example, 130 to 140°C, whereas the secondary vulcanization is carried out by placing the sheet in a thermostatic chamber and heat treating it for 2 to 4 hours at a high temperature of 200 to 220°C.

[0024] In order to obtain high impact resilience, the Shore A hardness of the base layer 11 after primary vulcanization and before secondary vulcanization, when measured in accordance with JIS K 6253, is lower than conventional values, 52°H to 59°H, preferably 55°H to 58°H, and more preferably 57.4°H. In contrast, in order to obtain high impact resilience, the Shore A hardness after secondary vulcanization, when measured in accordance with JIS K 6253, is lower than conventional values, 65°H to 71°H, preferably 68°H to 71°H, and more preferably 70.4°H.

[0025] To reduce residual distortion, the base layer 11 has a median compression set measured three times in accordance with JIS K 6262, which is half the conventional value, of 1.6% to 1.9%, preferably 1.7% to 1.85%, and more preferably 1.8%. Furthermore, when the base layer 11 is repeatedly subjected to 10 compression load displacement measurements using a specified testing machine, the first load difference between the compression load and the return load is lower than conventional values, 635 N to 655 N, preferably 640 N to 650 N, and more preferably 645 N, to reduce compressive deformation. The load difference at the tenth measurement is lower than conventional values, 299 N to 319 N, preferably 304 N to 314 N, and more preferably 309 N, to reduce compressive deformation.

[0026] When the compression load displacement of the base layer 11 is measured 10 times using a specified testing machine, from the viewpoint of improving durability, the difference in peak load between the first and tenth repeated compressions should be lower than conventional values, that is, 182N or more and 202N or less, preferably 187N or more and 197N or less, and more preferably 192N. The plurality of thin metal wires 12 embedded in the base layer 11 are the same as those in the conventional example, and therefore a description thereof will be omitted.

[0027] In the above, when manufacturing the anisotropic conductive connector 10, first, a plurality of resin films made of polyethylene terephthalate resin, polyester resin, or the like are prepared to form the base layer 11, and a paste molding material is dispensed and laminated evenly onto the surface of each of the plurality of resin films. After dispensing and laminating the molding material in this manner, a plurality of flexible thin metal wires 12 are arranged in a horizontal row at predetermined intervals on the surface of one molding material, and another molding material is laminated onto the surface of one molding material to form a core sheet sandwiching the plurality of thin metal wires 12.

[0028] The core sheet is then heat-press molded in a dryer under normal pressure, or heat-press molded in a heat-pressure treatment device for primary vulcanization, the resin film is peeled off from this primarily vulcanized core sheet, and a liquid silicone rubber adhesive layer is screen-printed on one side of the core sheet, and multiple core sheets are laminated and bonded together with the liquid silicone rubber interposed between them to form a block. The Shore A hardness of the primarily vulcanized core sheet, as measured in accordance with JIS K 6253, is 52°H to 59°H, preferably 57.4°H.

[0029] Once the block is constructed, it is degassed and post-vulcanized, and then cut into the desired size to produce the anisotropic conductive connector 10. The post-vulcanization is performed by placing the block in a thermostatic chamber equipped with a forced exhaust system and heat-treating it at a high temperature of approximately 205°C for two hours. The Shore A hardness of the post-vulcanized block, as measured in accordance with JIS K 6253, is preferably 65°H to 71°H, and more preferably 70.4°H. The base layer 11 of the manufactured anisotropic conductive connector 10 has a thickness of, for example, 0.3 mm to 1.5 mm, preferably 0.5 mm to 1.2 mm, and more preferably 0.5 mm to 1.0 mm.

[0030] According to the above, the base layer 11 of the anisotropically conductive connector 10 is formed into a rubber sheet using silicone rubber, which has at least excellent resilience and durability, so that the base layer 11 is less susceptible to compression deformation, and it is possible to apply approximately the same load or to make the amount of compression approximately the same when compressing the base layer 11 multiple times. Therefore, even if the anisotropically conductive connector 10 is repeatedly compressed and released, it is possible to reduce residual distortion in the base layer 11 and the multiple thin metal wires 12.

[0031] Furthermore, since it is possible to apply substantially the same load to the base layer 11 and to make the compression amount substantially the same, even if the thin metal wires 12 are made of a flexible material, the thin metal wires 12, which have low spring properties, can be easily restored by following the movement of the base layer 11. Therefore, it is possible to properly bring both ends of the thin metal wires 12 into close contact with the electrodes of the wiring board 1 for testing and the solder balls 4 of the BGA 3, and to reliably maintain the connection characteristics between the electrodes and the solder balls 4.

[0032] In addition, a silane coupling agent (e.g., product name KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) may be added to the molding material in the above embodiment as needed. The base layer 11 of the anisotropic conductive connector 10 may be sandwiched between the lower testing wiring board 1 and the upper printed wiring board. Furthermore, all of the technologies described in this specification may be subject to patent rights through amendments or divisional applications. [Example]

[0033] Examples of the anisotropically conductive connector according to the present invention will be described below together with comparative examples. [Example] To verify the performance of the anisotropic conductive connector, test pieces of the base layer were manufactured and the Shore A hardness, compression set, and compression load displacement of these test pieces were measured. In addition, the load characteristics, load and resistance values ​​of the anisotropic conductive connector were measured and the relationship between these was considered.

[0034] Test piece manufacturing and Shore A hardness A resin film made of polyethylene terephthalate resin was prepared, and a molding material for a test piece was evenly dispensed onto the surface of this resin film to form a core sheet. This core sheet was then hot-press molded in a dryer under normal pressure to undergo primary vulcanization, and the resin film was then peeled off from the primary vulcanized core sheet to obtain a test piece.

[0035] The molding material was prepared by blending 100 parts by mass of a silicone rubber paste, which offers excellent elasticity and durability, 0.5 parts by mass of catalyst C-19A (product name, manufactured by Shin-Etsu Chemical Co., Ltd.), which functions as a vulcanizing agent, and 5 parts by mass of crosslinking agent C-19B (product name, manufactured by Shin-Etsu Chemical Co., Ltd.), which improves rubber hardness. Primary vulcanization was performed by hot-press molding at a temperature of 135°C for 10 minutes. The Shore A hardness of this primary vulcanized test piece was measured using a Type A durometer in accordance with JIS K 6253 and was found to be 57.4°H.

[0036] Once the test pieces were obtained, they were degassed and post-vulcanized to obtain complete test pieces. The post-vulcanization was carried out by hot molding at a temperature of 205°C for 2 hours. The Shore A hardness of the post-vulcanized test pieces was measured using a Type A durometer in accordance with JIS K 6253 and was found to be 70.4°H.

[0037] Compression set of test piece A large test piece was placed in an environmental testing machine (manufactured by Isuzu Manufacturing Co., Ltd.: product name VTEC-154-H) conforming to JIS K 6262, and the original thickness h0 (mm) of the test piece, the thickness h1 (mm) of the test piece removed from the environmental testing machine, and the thickness h of the spacer were measured every hour. s The compression set CS (%) of the test piece was calculated from these values ​​using the specified formula (1). The compression set CS (%) of the test piece was measured three times, and the median value of the compression set CS (%) of the test piece was calculated and used as the median value of the compression set CS (%) of the test piece. These values ​​are summarized in Table 1.

[0038] The large test pieces were cut to a size of 29±0.5 mm in diameter and 12.5±0.5 mm in thickness. The test conditions were as follows: Test temperature: 70℃ Test time: 24 hours Compression ratio: 25% It was decided.

[0039] Formula (1) for calculating compression set is: CS=h0-h1 / h0-h s ×100 …(1) CS: Compression set (%) h0: original thickness of the specimen (mm) h1: Thickness of the test piece taken out of the environmental test chamber (mm) h s :Spacer thickness (mm) is.

[0040] Compression load displacement of test piece The compressive load displacement of a large test piece was measured 10 times repeatedly, and the load difference between the compressive load and the return load at the first time and the load difference at the tenth time were measured and shown in Figure 1, and summarized in Tables 2 and 3. In addition, when the compressive load displacement was measured 10 times repeatedly, the peak load difference between the first and tenth repeated compressions was measured and shown in Figure 2, and summarized in Table 4.

[0041] Large test pieces were cut to a size of 29 mm in diameter and 12.5 ± 0.5 mm in thickness, and placed in a universal testing machine to measure the compression load, return load, etc. The universal testing machine used was the RTF-1250 (product name, manufactured by A&D Co., Ltd.). The load cell used in this universal testing machine was the NUR-1KN-D (product name, manufactured by A&D Co., Ltd.) with a weight of 5 kgN.

[0042] The measurement conditions for the universal testing machine were as follows: the initial load of approximately 0.04 N was applied as the zero point, and the compression load was repeated 10 times using a compression jig. This cycle was repeated with an upper limit of 3.75 mm, a stop of 1 s, and a lower limit of 0.00 mm, a stop of 1 s. The compression speed was set to 1 mm / min, and the compression rate was 30% (compression amount 3.75 mm). The arrow in Figure 1 indicates 20% compression.

[0043] ·Load characteristics of anisotropic conductive connectors The anisotropic conductive connector shown in Figure 8 was manufactured, a surface mount semiconductor package was mounted on this anisotropic conductive connector, and the surface mount semiconductor package was compressed 20,000 times to measure the load characteristics. The measurement results are shown in Figure 3, and the load change rate at 0.06 mm compression is summarized in Table 5. The compression load and movement amount of the anisotropic conductive connector were also measured and are shown in Figure 4.

[0044] The anisotropic conductive connector was manufactured using the manufacturing method of the embodiment, in which multiple flexible pure gold wires with a diameter of 40 μm were arranged in a horizontal row at a predetermined interval on the surface of one molding material, and another molding material was laminated on the surface of the first molding material to form a core sheet sandwiching the multiple pure gold wires.In addition, the surface mount semiconductor package used was a PGA type in which multiple pins serving as electrode terminals were arranged at a predetermined interval in the X and Y directions on the lower surface of the package.

[0045] The load characteristics of the anisotropic conductive connector were measured by setting the anisotropic conductive connector in a universal testing machine. The universal testing machine used was the Tensilon RTF-1250 (product name, manufactured by A&D Co., Ltd.). The load cell used in this universal testing machine was the NUR-1KN-D (product name, manufactured by A&D Co., Ltd.) with a weight of 5 kgN.

[0046] In addition, the measurement conditions using a universal testing machine are as follows: Repeated compression times: 20,000 times Compression terminal: φ5mm Load: 1000N Position where the compressed terminal stops from the zero position: 0.15 mm Measurement speed: 0.1 (mm / min) Repeated compression speed: 100 (mm / min) Zero Level: Compression pause time: 1 second It was decided.

[0047] Comparative Example As in the examples, to verify the performance of the anisotropic conductive connector, test pieces of the base layer were manufactured, and the Shore A hardness, compression set, and compression load displacement of the test pieces were measured. In addition, the load characteristics, load and resistance values ​​of the anisotropic conductive connector were measured, and the relationship between these was considered.

[0048] Test piece manufacturing and Shore A hardness The molding material was prepared by blending 100 parts by mass of a general-purpose silicone rubber paste, 0.5 parts by mass of catalyst C-19A (product name, manufactured by Shin-Etsu Chemical Co., Ltd.) which functions as a vulcanizing agent, and 2.5 parts by mass of crosslinking agent C-19B (product name, manufactured by Shin-Etsu Chemical Co., Ltd.) which improves rubber hardness. Primary vulcanization was performed by hot press molding at a temperature of 135°C for 10 minutes. The Shore A hardness of this primary vulcanized test piece was measured using a Type A durometer in accordance with JIS K 6253, and was found to be 60.7°H.

[0049] Once the test pieces were obtained, they were degassed and post-vulcanized to obtain complete test pieces. The post-vulcanization was carried out by hot molding at a temperature of 205°C for 2 hours. The Shore A hardness of the post-vulcanized test pieces was measured using a Type A durometer in accordance with JIS K 6253, and was found to be 73°H.

[0050] Compression set of test piece Basically, the procedure was the same as in the Examples. After measuring the compression set CS (%) of the test piece three times, the median value of the compression set CS (%) of the test piece was calculated and used as the median value of the compression set CS (%) of the test piece. These values ​​are listed in Table 1.

[0051] Compression load displacement of test piece The load difference between the first and tenth compression loads was measured in the same manner as in the example, and is shown in Fig. 5 and listed in Tables 2 and 3. When the compression load displacement was measured 10 times repeatedly, the peak load difference between the first and tenth compression cycles was measured and shown in Fig. 2 and summarized in Table 4.

[0052] ·Load characteristics of anisotropic conductive connectors An anisotropic conductive connector for comparison was manufactured, a surface mount semiconductor package was mounted on this anisotropic conductive connector, and the surface mount semiconductor package was pressed down 20,000 times to measure the load characteristics, and the measurement results are shown in Figure 6 and listed in Table 5. The compression load and movement amount of the anisotropic conductive connector were also measured and are shown in Figure 7.

[0053] [Table 1]

[0054] [Table 2]

[0055] [Table 3]

[0056] [Table 4]

[0057] [Table 5]

[0058] 〔evaluation〕 The anisotropic conductive connector of the embodiment can reduce the compressive load to 40% or less, as is clear from a comparison of Figures 3 and 6. Furthermore, as is clear from a comparison of Figures 4 and 7, unlike the comparative example, the region in which the connection is maintained can be extended even when the compression is released. [Industrial Applicability]

[0059] The anisotropic conductive connector according to the present invention is used in fields such as wiring boards and semiconductor packages. [Explanation of symbols]

[0060] 1. Test wiring board (electrical joint) 3 BGA (electrical joint, surface mount semiconductor package) 4 solder balls 10 Anisotropic conductive connector 11 Base Layer 12 Fine metal wire (conductive thin wire)

Claims

1. An anisotropic conductive connector including a base layer interposed between a plurality of electrical connecting members, and a plurality of flexible conductive thin wires embedded in the base layer and having both ends exposed, the ends of the conductive thin wires being in conductive contact with the electrical connecting members, The base layer is formed into a rubber sheet by primary vulcanization and secondary vulcanization of a molding material containing silicone rubber, which has excellent impact resilience and durability, and the Shore A hardness before secondary vulcanization, measured in accordance with JIS K 6253, is 52°H or more and 59°H or less, and the Shore A hardness after secondary vulcanization, measured in accordance with JIS K 6253, is 65°H or more and 71°H or less.

2. 2. The anisotropic conductive connector according to claim 1, wherein the base layer is sandwiched between the wiring board and the surface-mount semiconductor package.

3. 3. The anisotropically conductive connector according to claim 1, wherein the base layer has a median compression set of 1.6% or more and 1.9% or less, measured multiple times in accordance with JIS K 6262.

4. 3. An anisotropic conductive connector as described in claim 1 or 2, wherein when the compressive load displacement of the base layer is repeatedly measured 10 times, the load difference between the compressive load and the return load for the first time is 635 N or more and 655 N or less, and the load difference for the tenth time is 299 N or more and 319 N or less.

5. 5. The anisotropic conductive connector according to claim 4, wherein when the base layer is repeatedly compressed and the displacement under a compressive load is measured ten times, the difference in peak load between the first and tenth compressed times is 182 N or more and 202 N or less.

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