JP2010065188A - Electroconductive adhesive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electroconductive adhesive sheet, having an adhesive surface, capable of being attached without using an adhesive and imparting good electric connection by being inserted between boxes or the like, and having good workability in attaching the same. <P>SOLUTION: The electroconductive adhesive sheet 10 includes an electroconductive powder in an elastic polymer and comprises two or more electroconductive parts 1 and insulation parts 2, wherein the electroconductive powder is arranged in the thickness direction in a mutually contacted state and the insulation parts 2 mutually and insulatively hold the electroconductive parts. The hardness of the electroconductive adhesive sheet 10 is ≥10 and ≤100 in degree of needle penetration and the surface adhesive force is in a range of ball tack of ≥No.4 and ≤No.20 in ball tackiness force. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a conductive pressure-sensitive adhesive sheet having conductivity in the thickness direction of the sheet.

  In recent years, electromagnetic interference such as malfunction of other electronic devices due to electromagnetic noise radiated from electronic devices such as mobile phones, laptop computers, car navigation systems, and influences on human bodies has become a problem. Electronic devices are increasingly equipped with wireless components that emit radio waves, and there are many inconveniences such as failure in receiving broadcast radio waves and global positioning system (GPS) radio waves. As countermeasures, devices have a shielding structure that covers shield parts, multilayer circuit boards and parts on the board in order to prevent these obstacles, or make the housing itself conductive to provide shielding. Many technologies are used. However, the use of these construction methods and conductive parts alone does not provide sufficient countermeasures against radio wave interference, and many parts with various shielding properties have been developed and used as countermeasures.

  Conventionally, the thing of various structures is known as an electroconductive sheet used for such a use. For example, a conductive sheet (Patent Document 1) in which metal particles are uniformly dispersed in rubber, and a plurality of conductive circuits extending in the thickness direction of the sheet by dispersing conductive powder in a polymer material. Conductive sheet (Patent Document 2) in which an insulating part to be insulated is formed, Anisotropic conductive sheet (Patent Document 3) in which a step is formed between the conductive part and the insulating part of the anisotropic conductive sheet, Adhesiveness An anisotropic conductive sheet containing an improver (Patent Document 4) has been proposed. These anisotropic conductive sheets are contained in an insulating base material made of an elastic polymer in a state in which conductive particles are aligned so as to be aligned in the thickness direction. A road is formed.

When these conductive sheets are sandwiched between an electric circuit having a potential difference or a metal casing and pressed for electrical connection, the conductive sheet needs to be fixed to the casing surface or the like. However, if a large amount of conductive filler is mixed and filled in the polymer material in order to obtain the required conductivity, the surface of the sheet becomes smooth, the surface adhesiveness is remarkably reduced, and the surface adhesiveness is sacrificed. End up. When these conductive sheets having a smooth sheet surface are adhesively fixed to the housing, it is necessary to form an adhesive part in which an adhesive or the like is previously applied to the sheet surface. Furthermore, since the conductive sheet in which metal particles are uniformly dispersed in a large amount in rubber is filled with a large amount of expensive conductive filler, there is a problem that the conductive sheet becomes expensive. Furthermore, these products have a problem that the strength is low, the conductive sheet is torn easily and tears, and it cannot be reused and repair workability is difficult.
JP 51-93393 A Japanese Patent Laid-Open No. 53-147772 JP-A-61-250906 JP 2006-335926 A

  In order to solve the above-mentioned conventional problems, the present invention can adhere to the surface of the sheet without using an adhesive, and can be sandwiched between cases to obtain a good electrical connection. Provided is a conductive pressure-sensitive adhesive sheet having good workability when attached.

  The conductive pressure-sensitive adhesive sheet of the present invention is a conductive pressure-sensitive adhesive sheet in which conductive magnetic powder is contained in an elastic polymer, and the conductive magnetic powder is oriented in the thickness direction in the sheet and in contact with each other. The conductive adhesive sheet has a penetration of 10 or more and 100 or less, and the surface adhesive force is ball tack force. Ball tack No. 4 or more The range is 20 or less.

  The present invention includes a portion where conductive magnetic powder gathers to conduct electricity in the thickness direction of the sheet, and an insulating portion made of the elastic polymer, and the hardness is 10 to 100 in terms of penetration, Adhesive strength is ball tack force. 5-No. By being in the range of 11, the surface of the sheet is sticky, and can be sandwiched between the casings to obtain a good electrical connection, and a conductive pressure-sensitive adhesive sheet with good workability at the time of attachment can be provided. In other words, since there is electrical conductivity in the thickness direction of the sheet, it is possible to electrically conduct each other when sandwiched between the casings. Furthermore, since the elastic polymer portion on the surface of the sheet other than the aggregate portion of the conductive magnetic powder has adhesiveness, it becomes a joined state such that the casings are joined with a double-sided tape by the adhesive force, With respect to external factors such as vibration and impact received by the casing, good adhesiveness can be exhibited without applying an adhesive or the like, and good electrical conductivity can be maintained.

  The anisotropic conductive pressure-sensitive adhesive sheet of the present invention is a sheet including a portion in which conductive magnetic powder is arranged in an elastic polymer material and disposed as an aggregate, and the aggregate of the conductive magnetic powder is in the form of a sheet. They are arranged in the thickness direction. Since conductive magnetic powder is arranged and arranged as an aggregate in the conductive path in the sheet, the minimum necessary conductive magnetic powder is used for conductivity. Furthermore, the arrangement of the conductive magnetic powder in the sheet, the position of the aggregate, the density, etc. can be freely designed according to the desired electrical characteristics. Furthermore, the surface of the other rubber part where the conductive magnetic powder is not gathered has the adhesiveness of the rubber itself. The thickness of the conductive pressure-sensitive adhesive sheet is 0.10 mm to 0.5 mm, particularly preferably 0.10 mm to 0.30 mm. Hereinafter, each member will be described.

  Examples of the elastic polymer material of the conductive adhesive sheet containing conductive magnetic powder include isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, and ethylene propylene. Rubber, acrylic rubber, urethane rubber, silicone rubber, fluoro rubber, polyester rubber, styrene butadiene rubber, and the like. It is important that these polymer materials have liquid or fluidity for the purpose of appropriately mixing the conductive magnetic powder during sheet molding. Since it is liquid at room temperature and needs to be able to be cured by heating to form a sheet, use a polymer material that is fluid at the time of sheet molding and can be molded even if it is solid at room temperature Can do. Among the liquid silicone rubbers, addition reaction type liquid silicone rubber is preferable. This addition reaction type liquid silicone rubber is cured by a reaction between a vinyl group and a Si—H bond, and is a two-component type of A and B parts made of a polysiloxane containing a vinyl group and a polysiloxane containing a Si—H bond. Are commercially available.

  The addition reaction type liquid silicone rubber becomes a crosslinked structure after sheet molding, and is preferable from the viewpoint of required characteristics such as durability and heat resistance. Depending on the application, the elasticity may be high or low, and the adhesiveness may be high or low. These elastic polymer materials are selected without being limited to the above examples. The addition reaction type liquid silicone rubber of the present invention preferably has a viscosity of 5P to 300P at room temperature (25 ° C.), more preferably 20P to 200P. When the viscosity of the addition reaction type liquid silicone rubber is less than 5P, the conductive magnetic powder settles in the silicone rubber when the sheet is molded, and when the magnetic field is applied, the conductive magnetic powder is It becomes difficult to arrange and arrange as an aggregate to form a conductive chain. On the other hand, when the viscosity exceeds 200 P, it becomes difficult to form conductive chains by arranging the conductive magnetic powder as an aggregate when a magnetic field is applied when the sheet is molded. The penetration of the addition reaction type liquid silicone rubber at normal temperature (25 ° C.) after curing is preferably 10 to 100, more preferably 25 to 70 (ASTM D1403 1/4 cone).

  When the penetration of the addition reaction type liquid silicone rubber is less than 10, the conductive pressure-sensitive adhesive sheet has a weak adhesive force, and the conductive pressure-sensitive adhesive sheet cannot be fixed to the housing or the substrate during the assembly operation of the electronic equipment. On the other hand, when the penetration exceeds 100, when the conductive adhesive sheet is pressurized, the conductive parts arranged as an aggregate of conductive magnetic powder are excessively soft and cannot hold the conductive path. It becomes easy to be distorted, and the conductive path cannot be held here. In addition, it is extremely soft and tears immediately, making it extremely difficult to handle. The penetration is measured according to the measuring method ASTM D1403. As the addition reaction type liquid silicone rubber having such characteristics, those commercially available as CY52-276 (product name, manufactured by Toray Dow Corning Co., Ltd.) can be used.

  As the conductive magnetic powder mixed in the elastic polymer material, magnetically arranged in the sheet and arranged as an aggregate, substantially spherical particles are preferable. Moreover, it is a powder which has a ferromagnetic characteristic and the surface has electroconductivity. The material may be a single magnetic metal, an alloy with other metals, or composite particles. The core material may be an inorganic material, and coated type particles in which only the surface is covered with a magnetic metal may be used. As such conductive magnetic powder, nickel, iron, cobalt and other ferromagnetic metal particles or alloy particles containing these, or the surface of these particles plated with gold, palladium, silver, tin, etc., Alternatively, the surface of these alloys may be coated by a plating method or the like, or the above-described plating may be applied to particles using a non-magnetic metal powder or resin, glass, carbon powder or the like as a core material to form a conductive magnetic powder. More preferably, nickel particles which are ferromagnetic materials are used as a core material, and the surface thereof is plated with gold having excellent conductivity. The means for coating the surface of the core material with gold plating or the like is not particularly limited, but can be performed by, for example, electroless plating. After performing nickel plating using graphite powder as a core material, a conductive magnetic powder can be obtained by applying the gold plating having excellent conductivity by the above-described method.

  The average particle size of the conductive magnetic powder is preferably 1 μm to 300 μm, more preferably 10 μm to 150 μm. The particle size distribution of the conductive magnetic powder is preferably 60 μm to 100 μm. Any shape that allows easy electrical contact between the conductive magnetic powders by pressure deformation, spherical or star-shaped, mine-like, from the viewpoint that it can be easily mixed and dispersed in the elastic polymer material, A complex tow shape is preferred. The particle size of the conductive magnetic powder is measured by laser diffraction analysis.

  The surface of the conductive magnetic powder is preferably surface-treated with a coupling agent such as a silane coupling agent. By treating the surface of the conductive magnetic powder with a silane coupling agent, the adhesion between the conductive magnetic powder and the elastic polymer material is improved. As a result, the aggregate of the conductive magnetic powder in the conductive adhesive sheet is improved. It becomes an electroconductive adhesive sheet of the stable electroconductive characteristic, without arrangement | positioning disintegrating. The kind of the silane coupling agent, the treatment method for the conductive magnetic powder, and the treatment amount are appropriately selected within a range that does not affect the conductivity. The type of silane coupling agent is appropriately selected in consideration of the type of surface treatment of the conductive magnetic powder and the type of elastic polymer material. As the silane coupling agent having such characteristics, a commercially available primer D (product name, manufactured by Toray Dow Corning Co., Ltd.) can be used. The treatment amount of the silane coupling agent is preferably the minimum coverage area of the silane coupling agent. Surface treatment with a silane coupling agent is important for arranging conductive parts in a sheet, arranged as an aggregate, having elasticity, maintaining conductivity, and maintaining the surface adhesion of the conductive adhesive sheet It is.

  It is preferable to arrange a conductive mesh on the single-sided surface layer portion of the conductive pressure-sensitive adhesive sheet. The material of the conductive fibrous fabric is selected from conductive or insulating materials. As the conductive material, for example, a metal having a thickness of 10 to 30 μm such as copper wire, phosphor bronze wire, brass wire, nickel wire, tungsten wire, etc. Selected from thin lines. Or you may choose from the electroconductive thickness 10-30 micrometers thin wire which plated and vapor-deposited conductors, such as copper and nickel. The insulating material is selected from insulating polymers, for example, a thin wire having a thickness of 10 to 60 μ, such as a nylon wire, a polyester wire, or a PET wire. Or you may choose from the electroconductive thickness 10-60 micrometers thin wire which plated and vapor-deposited conductors, such as copper and nickel. They are woven in a flat shape using plain weave or twill weave. When a conductive mesh fabric is used, for example, the embodiment shown in FIG. 2 is preferable because the conductivity of the product is improved. In the embodiment of FIG. 3, conductivity is not necessarily required, and a mesh fabric using synthetic fibers such as non-conductive polyester fiber, nylon fiber, polyolefin fiber, etc. may be used.

  For example, the conductive pressure-sensitive adhesive sheet can be molded as follows. FIG. 5 is a schematic cross-sectional view of a magnetic molding die for producing a conductive adhesive sheet in one embodiment of the present invention. After preparing a compound in which conductive magnetic powder is dispersed in an addition reaction type liquid silicone rubber, this compound 27 is injected into the magnetic mold 20. The magnetic molding die 20 includes an upper die 23 composed of a magnetic material portion 21 and a nonmagnetic material portion 22, and a lower die 26 composed of a magnetic material portion 24 and a nonmagnetic material portion 25.

  FIG. 6 is a sectional view showing a magnetic molding machine 30 using the magnetic molding die 20. In the magnetic molding machine 30, an electromagnetic coil 32 is wound around an electromagnetic core material 31, and a magnetic orientation force in a predetermined direction is applied to the electromagnetic core material 31 by energizing the electromagnetic coil 32. The magnetic molding die 20 is heated by heating a hot plate 34 having a heater 33 below and / or above the magnetic molding die 20. Further, a press mechanism 35 for applying pressure to the magnetic molding die 20 is provided.

  The compound 27 in which the conductive magnetic powder is dispersed in the addition reaction type liquid silicone rubber is put into the magnetic molding machine 30 and the electromagnetic coil 32 is energized to cause magnetism to act in the thickness direction of the compound 27. As a result, the conductive magnetic powder dispersed in the compound 27 is gathered by the magnetism in the mold and arranged side by side in the thickness direction. In this state, the temperature of the hot plate 34 of the magnetic molding machine is raised and the compound 27 is thermoset.

  FIG. 1A is a cross-sectional view of a conductive pressure-sensitive adhesive sheet 10 in one embodiment of the present invention, and FIG. 1B is a plan view thereof. As shown in FIGS. 1A and 1B, a portion (conductive portion) 1 in which conductive magnetic powder is densely gathered in an addition reaction type liquid silicone rubber, and a rubber portion that does not or hardly exist in the addition reaction type liquid silicone rubber ( Insulating part) 2. The curing conditions for the conductive pressure-sensitive adhesive sheet are appropriately selected depending on the type of addition reaction type liquid silicone rubber to be used, but are usually cured by heat curing. Room temperature curable silicone rubber can also be used. It is appropriately selected in consideration of specific temperature, pressure, time, heat curing conditions depending on the blending amount of the conductive magnetic powder, and the like.

  The conductive magnetic powder of the conductive part in which the conductive magnetic powder is arranged and arranged as an aggregate is preferably 10 to 21% by volume with respect to 100% by volume of the conductive polymer material. If this ratio is less than 10% by volume, sufficient electrical conductivity may not be obtained. On the other hand, if this ratio exceeds 21% by volume, the conductive part is brittle and the mechanical properties are lowered. Furthermore, the elasticity and the resilience required for the conductive part tend not to be obtained.

The electric resistance in the thickness direction of the conductive adhesive sheet may be 0.5Ω or less in a state where it is pressed with a load of 30 gr / mm ² while being sandwiched in parallel with a flat electrode plated with gold on a glass epoxy substrate. preferable.

  The conductive adhesive sheet has a penetration of 10 to 100. When the penetration is less than 10, the adhesive strength of the sheet is weak, and the sheet cannot be fixed to the casing or the substrate during the assembly operation of the electronic equipment. When the sheet exceeds 100, when the sheet is pressed, the aggregate portion of the conductive magnetic powder is soft and cannot hold the conductive path by compression. A preferable penetration is 30 to 75. More preferably, it is 25-75.

  The surface tack of the anisotropic conductive adhesive sheet is No. 4-No. 20. More preferably, the ball tack force No. 5-No. 11 range. Ball tack force is no. If it is less than 4, the adhesive strength of the sheet becomes weak, and the sheet cannot be fixed during the assembly work of the electronic equipment. When the ball tack force exceeds 20, the sheet has a strong adhesive force, and the work becomes difficult at the time of assembling work. The measuring method of the ball tack force was JIS-Z0237, and the angle of the inclined plate was 30 degrees.

  FIGS. 2A-B and FIGS. 3A-B are examples in which the conductive mesh fabric in another embodiment of the present invention is disposed on the one-side surface layer portion of the conductive adhesive sheet. 2A is a cross-sectional view in which the constituent fiber yarns (warp and / or weft) 3 of the conductive fibrous fabric are arranged on the single-sided surface layer portion of the conductive adhesive sheet 11 and the conductive portion 1, and FIG. 2B is the same plan view. is there. FIG. 3A is a cross-sectional view in which constituent fiber yarns (warps and / or wefts) 3 of a conductive fibrous fabric are arranged on one side of the anisotropic conductive adhesive sheet 12 and in the insulating portion 2, and FIG. 3B is the same plane. FIG. As described above, when the conductive mesh fabric is integrated on one side of the conductive adhesive sheet, the surface becomes a non-adhesive surface, and only the other surface has adhesiveness, and the conductive adhesive sheet has good handleability. .

  FIG. 4 is a cross-sectional view of a conductive adhesive sheet 13 having a non-adhesive layer 4 formed on one side thereof in still another embodiment of the present invention. As an example, the non-adhesive layer 4 is liquid and transfers a crosslinking agent such as an organohydrogenpolysiloxane containing three SiH groups in one molecule from the polyester film to the surface of one side of the compound sheet, and is heated. Crosslinking is performed with a high crosslinking density. Even if it does in this way, a handleability improves.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not construed as being limited to the following examples.

Example 1
For 100% by weight of 60% by weight nickel graphite conductive magnetic powder having an average particle size of 80 μm (60% by weight of nickel, 40% by weight of graphite powder, powder obtained by electroless nickel plating using graphite powder as a core material), The powder surface-treated with primer D (trade name, manufactured by Toray Dow Corning Co., Ltd.) 0.1% by weight was prepared. Next, the filler is mixed with 2.5% by weight of silicone rubber, CY52-276 (product name, manufactured by Toray Dow Corning Co., Ltd.) 100% by weight, and then the air in the composition is vacuumed. The formulation 1 was prepared by removing.

Next, this compound 1 was sandwiched between polyethylene terephthalate (PET) films having a thickness of 0.1 mm, rolled to a thickness of 0.22 mm, formed into a sheet, and then placed in a magnetic mold shown in FIG. First, 0.6 ampere (A) and 13.5 volts (V) of electricity were applied to the electromagnetic coil from a DC power source, and conductive magnetic powders were assembled and arranged. Next, the press was closed to a predetermined position. At this time, the press operated to a predetermined position and the sheet was sandwiched. Strictly speaking, the pressure was applied by the weight of the press, but no positive pressure was applied. Thereafter, the blend sheet was heat cured at a temperature of 80 ° C. for 20 minutes. Thereafter, the PET films on both sides were peeled off to obtain a sheet having a thickness of 0.2 mm. The obtained sheet is as shown in FIGS. 1A-B, the conductive particle aggregates are arranged in a matrix in the plane direction at a pitch of 1 mm, and the size of the aggregates is a circle with a diameter of 0.75 mmφ, The resistance value per 10 mm ² is 400 mΩ at 5% compression, the penetration is 55, the ball tack force is ball tack No. 7.

(Example 2)
Primer D (100% by weight of 15% silver / nickel conductive magnetic powder having an average particle size of 40 μm (silver 15% by weight, nickel powder 85% by weight, powder plated with nickel powder as a core material) The powder surface-treated with 0.1% by weight (trade name, manufactured by Toray Dow Corning Co., Ltd.) was prepared. Next, 90% by weight of the filler is mixed with 100% by weight of silicone rubber, CY52-276 (product name, manufactured by Toray Dow Corning Co., Ltd.), and then the air in the composition is evacuated in a vacuum state. Formulation 2 was made.

Next, after blending this compound 2 with a thickness of 0.1 mm between polyethylene terephthalate films and rolling to 0.22 mm, it was placed in a magnetic mold as in Example 1 and heat-cured at 80 ° C. for 20 minutes with a magnetic molding machine. The films on both sides were peeled off to obtain a sheet having a thickness of 0.2 mm. The obtained sheet is as shown in FIGS. 1A and 1B, and the conductive particle aggregates are arranged in a matrix in the plane direction at a pitch of 1 mm, and the size of the aggregate is a circular shape of 0.70 mm, 10 mm The electrical resistance value per ² is 100 mΩ at 5% compression, the penetration is 63, and the ball tack force is ball tack no. 7.

(Example 3)
Primer D (100% by weight of 15% silver / nickel conductive magnetic powder having an average particle size of 40 μm (silver 15% by weight, nickel powder 85% by weight, powder plated with nickel powder as a core material) The powder surface-treated with 0.1% by weight (trade name, manufactured by Toray Dow Corning Co., Ltd.) was prepared. Next, after mixing 30% by weight of the filler with 100% by weight of silicone rubber, CY52-276 (product name, manufactured by Toray Dow Corning Co., Ltd.), the mixture is evacuated to release air in the composition. A formulation sheet 3 having a thickness of 0.2 mm was prepared.

After applying a primer (product name: Primer D, manufactured by Toray Dow Corning Co., Ltd.) on one side of the compound sheet 3, the primer sheet is thoroughly dried at room temperature, and a conductive fibrous fabric (Seiren product name, “Su-10-33”, yarn material: Cu was plated on the surface of PET with a Cu plating thickness of 62 μm and a surface resistance of 0.02 Ω / Sq). Next, 0.1 mm thickness, sandwiched from both sides with a polyethylene terephthalate film, put in a magnetic molding die as in Example 1, heat cured at 80 ° C. for 20 minutes with a magnetic molding machine, peel off the films on both sides and thicken A sheet with a thickness of 0.56 mm was obtained. The obtained sheet was as shown in FIGS. 2A-B, and the conductive particle aggregates were arranged in a matrix in the plane direction at a pitch of 1 mm. Moreover, the size of the aggregate was a circle of 0.55 mm, and the electrical resistance value per 10 mm ² was 600 mΩ when compressed at 5%. The penetration was 63. Also, the ball tack force on the opposite side where the conductive fibrous fabric is not attached is No. It was 5. A conductive adhesive sheet having adhesiveness only on one side and good handleability was obtained.

Example 4
Primer for 100% by weight of nickel-graphite conductive magnetic powder with an average particle size of 80 μm (60% by weight of nickel, 40% by weight of graphite powder, powder obtained by electroless nickel plating using graphite powder as a core) The powder surface-treated with D (trade name, manufactured by Toray Dow Corning Co., Ltd.) 0.1% by weight was prepared. Next, the filler is mixed with 2.5% by weight of 100% by weight of silicone rubber, CY52-276 (product name, manufactured by Toray Dow Corning Co., Ltd.), and then the composition is air in the composition in a vacuum state. A formulation 4 was prepared.

Next, the electroconductive adhesive sheet which raised the crosslinking density only on one side was created as follows. A treatment film was prepared in which a liquid organoorganopolysiloxane containing 3 SiH groups in one molecule was applied to a thickness of 10 μm on one side of a 0.1 mm thick polyethylene terephthalate film using a screen printer. The compound 4 was placed on the treated film, covered with a 0.10 mm thick polyethylene terephthalate film on the other side, and rolled into a 0.5 mm thick sheet. Next, as in Example 1, it was placed in a magnetic molding die and heat-cured at 80 ° C. for 20 minutes with a magnetic molding machine, and the films on both sides were peeled off to obtain a sheet having a thickness of 0.5 mm. The obtained sheet is as shown in FIG. 4, and the conductive particle aggregates are arranged in a matrix in the surface direction at a pitch of 1 mm, and the aggregate size is a circular shape of 0.75 mm per 10 mm ^2. The electrical resistance value was 400 mΩ at 5% compression, and the penetration was 63. The ball tacking force on the surface opposite to the surface with the increased crosslink density (non-adhesive layer 4) was No. 3. It became the electroconductive adhesive sheet which has adhesiveness only on one side. In the non-adhesive layer 4, the liquid organoorganopolysiloxane containing three SiH groups in one molecule is transferred from the polyester film to the surface of one side of the compound sheet and crosslinked in a high concentration state. It is formed by. Even if it does in this way, handling property improves.

  Using the conductive adhesive sheets of Examples 1 to 4 obtained as described above, sandwiching between electric circuits with different potentials or metal casings, and pressurizing to make electrical connection, the surface of the casing is simple. The conductive sheet could be fixed to the conductive adhesive sheet, and a conductive adhesive sheet convenient for work was obtained. In addition, these anisotropically conductive adhesive sheets can be used to obtain a conductive sheet suitable for electrical connection by being sandwiched between an electric circuit or a metal casing having a potential difference and pressurizing. A good conductive sheet was obtained.

  As described above, the conductive pressure-sensitive adhesive sheet of the present invention does not mix and fill a large amount of conductive filler in the sheet in order to obtain conductivity. Therefore, the surface of the pressure-sensitive adhesive sheet is sufficiently sticky. Further, the conductive particles are arranged and arranged as an aggregate, have electrical conductivity through a chain of contact of the conductive particles, and the surface of the sheet has a sufficient adhesive force to adhere and fix to the housing. The anisotropic conductive pressure-sensitive adhesive sheet of the present invention does not need to be coated with a pressure-sensitive adhesive for developing adhesiveness, and does not need to disperse a large amount of metal particles in an elastic polymer material, so that sufficient electrical conductivity can be obtained. Can be obtained. It can be set as the electroconductive adhesive sheet provided with the adhesive force and electrical conductivity for the purpose of fixation.

FIG. 1A is a sectional view of a conductive pressure-sensitive adhesive sheet in one embodiment of the present invention, and FIG. 1B is a plan view of the same. FIG. 2A is a cross-sectional view in which a conductive fibrous fabric according to another embodiment of the present invention is disposed on a single-sided surface layer portion of a conductive pressure-sensitive adhesive sheet, and FIG. 2B is a plan view thereof. FIG. 3A is a cross-sectional view in which a conductive fibrous fabric according to still another embodiment of the present invention is disposed on a single-sided surface layer portion of a conductive pressure-sensitive adhesive sheet and an insulating portion, and FIG. 3B is a plan view thereof. FIG. 4 is a cross-sectional view of a conductive pressure-sensitive adhesive sheet having a non-adhesive layer formed on one side in yet another embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of a magnetic molding die for producing a conductive adhesive sheet in one embodiment of the present invention. FIG. 6 is a sectional view showing a magnetic molding machine using the magnetic molding die of FIG.

Explanation of symbols

1 Part where conductive magnetic powder is gathered densely (conducting part)
2 Rubber part (insulating part)
3 Constituent fiber yarn of conductive mesh fabric 4 Non-adhesive layer 10, 11, 12, 13 Conductive adhesive sheet 20 Magnetic molding die 21, 24 Magnetic material portion 22, 25 Non-magnetic material portion 23 Upper die 26 Lower die 27 Compound 30 Magnetic Molding Machine 31 Electromagnetic Core Material 32 Electromagnetic Coil 33 Heating Heater 34 Hot Plate 35 Press Mechanism

Claims (11)

A conductive pressure-sensitive adhesive sheet containing conductive magnetic powder in an elastic polymer,
A plurality of conductive portions in a state where the conductive magnetic powder is oriented in the thickness direction in the sheet and in contact with each other, and an insulating portion that holds these conductive portions insulated from each other;
The conductive adhesive sheet has a hardness of 10 to 100 in terms of penetration,
The surface adhesive force is ball tack force and ball tack no. 4 or more A conductive pressure-sensitive adhesive sheet having a range of 20 or less.   2. The conductive adhesive sheet according to claim 1, wherein a ratio of the conductive magnetic powder in the conductive part is in a range of 10 to 21% by volume with respect to 100% by volume of the elastic polymer.   The conductive adhesive sheet according to claim 1, wherein the conductive magnetic powder is a substantially spherical powder having a diameter of 1 μm to 300 μm.   The conductive adhesive sheet according to any one of claims 1 to 3, wherein the conductive magnetic powder is contained in an amount of 2.5 to 90 parts by weight in 100 parts by weight of the elastic polymer.   The conductive pressure-sensitive adhesive sheet according to claim 1, wherein the surface of the conductive magnetic powder is subjected to a conductive anticorrosion treatment.   The conductive adhesive sheet according to claim 1, wherein the surface of the conductive magnetic powder is treated with a silane coupling agent. The electric resistance in the thickness direction of the conductive adhesive sheet is 0.5Ω or less in a state of being sandwiched in parallel between flat electrodes plated with gold on a glass epoxy substrate and under a pressure of 30 gr / mm ^2. The conductive adhesive sheet according to any one of claims 1 to 6.   The conductive adhesive sheet according to any one of claims 1 to 7, wherein the conductive adhesive sheet has a penetration of 25 to 75.   The surface adhesive strength of the conductive adhesive sheet is No. 5-No. It is the range of 11. The electroconductive adhesive sheet in any one of Claims 1-8.   The conductive adhesive sheet according to any one of claims 1 to 9, further comprising a conductive fibrous fabric disposed on a single-sided surface layer portion of the conductive adhesive sheet.   The electroconductive adhesive sheet in any one of Claims 1-9 which formed the non-adhesion layer which raised the crosslinking density further in the single-sided surface layer part of the said electroconductive adhesive sheet.

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