JP2001351445A - Manufacturing method of compound sheet and compound sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anisotropic conductive compound sheet which is capable of having a higher density of a conductive part as formed in a given position, has a low-resistance conductive part with a high anisotropic conductivity toward width direction, has good heat resistance, endurance, mechanical intensity, and adhesion with semiconductor devices, and provide a heat-conductive compound sheet with a similar manufacturing method. SOLUTION: A sheet-shaped composition 7 which is structured with a fibrous filler 5 having a magnetism and/or a binder 6 curing by light, is held between magnetic polar boards 11 consisting of a pair each of a magnetic polar boards 8 having projected magnetic polar surfaces 12 and of electromagnets 10, and is applied with a magnetic field parallel to the perpendicular direction of the sheet-shaped composition, and the binder is cured by heating or the like of the sheet-shaped composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a composite sheet and a composite sheet.

[0002]

2. Description of the Related Art In recent years, the number of electrodes of a semiconductor element has increased due to the high performance, miniaturization, or high-density wiring of electric or electronic equipment, and the inspection and inspection of electric circuit components, electric circuit boards, etc. The measurement or the electrical connection between them is performed through a fine pitch between electrodes. The electrode pitch of such a semiconductor element also tends to be further miniaturized. In mounting the semiconductor element on a substrate and inspecting the same, the miniaturized electrode pitch is securely connected with a low resistance without a short circuit. Is becoming a big issue.

In response, a compact electrical connection is achieved without using means such as soldering or mechanical fitting, and a soft connection is made possible by absorbing mechanical shock and distortion. Development of an anisotropic conductive sheet has been attempted. For example, JP-B-56-48951, JP-A-51-93393, and JP-A-53-147772.
Japanese Patent Application Laid-Open No. 54-146873 and JP-A-54-146873 disclose a conductive material having conductivity only in the thickness direction of a sheet or a plurality of pressurized conductive materials having conductivity only in the thickness direction when pressed. Anisotropic conductive sheets having various structures such as having a portion are described. Such anisotropic conductive materials can be used to ensure reliable electrical connection without damaging electrodes during electrical inspection of a circuit board or the like. It is effective in that it can be achieved, and among these, an anisotropic conductive sheet having conductive particles in a resin, wherein the conductive particles are oriented in the thickness direction of the sheet to form a conductive portion. Was particularly effective for connection of a finer electrode pitch.

[0004] However, in order to cope with further miniaturization of electrode dimensions and interelectrode dimensions of electronic circuit boards and the like, and further advancement of densification, further miniaturization of conductive portions of an anisotropic conductive sheet is required. Had become. For example, the pitch interval between conductive parts such as semiconductor elements has been 500 μm.
The electrode pitch of the conductive part such as a semiconductor element is becoming finer and finer, such as the appearance of electronic circuit boards with a pitch interval of 100 μm or less. In order to ensure accurate and reliable electrical connection between the conductive portion of the anisotropic conductive sheet formed by the orientation and the like, and the conductive portion of the semiconductor element or the like, the distance between the conductive portions in the anisotropic conductive sheet is required. For example, several tens μm
It has been necessary to further increase the density of the conductive portions of the anisotropic conductive sheet, for example, by setting the interval to about the same.

[0005] Therefore, in an anisotropic conductive sheet in which conductive particles are formed in a resin and the conductive particles are oriented in the thickness direction of the sheet to form a conductive portion, an anisotropic conductive sheet is used. Attempts have been made to develop an anisotropic conductive sheet in which the conductive particles contained in the sheet are miniaturized and the conductive fine particles are oriented in the thickness direction. However, even if the pitch interval of the conductive portion of the anisotropic conductive sheet is reduced by using such fine conductive particles, the conductive particles are oriented in the thickness direction of the anisotropic conductive sheet with the miniaturization of the conductive particles. There is a problem in that the contact resistance between the conductive particles increases and the conductivity decreases. Further, when the density of the conductive portion of the anisotropic conductive sheet is increased, the orientation of the conductive particles during molding of the anisotropic conductive sheet is an important factor. There is also a problem that the frequency of contact of the conductive portion composed of the rows of conductive particles oriented in a high frequency increases, and the thickness and the insulating property in the vertical direction may decrease. Furthermore, in order to reduce the contact resistance between such fine conductive particles or reduce the contact between the conductive parts, an attempt was made to reduce the thickness of the anisotropic conductive sheet. There has been a problem that thickness variation, sheet distortion and the like occur, and the durability of the anisotropic conductive sheet decreases.

Accordingly, the present inventors have conducted intensive studies to solve the above-mentioned problems, and in a binder in a hardened or semi-hardened state, a fibrous filler having a magnetic substance and a noble metal adhered to the surface thereof in the thickness direction of the sheet. According to the anisotropic conductive sheet in which the bundles of the fibrous filler are unevenly distributed at predetermined positions of the sheet, the conductive portion made of the fibrous filler can be accurately corresponded to a desired position, and the anisotropic conductive It has been found that it is possible to make the pitch interval between the conductive portions in the conductive sheet fine. In addition, according to the conductive portion formed by the fibrous filler, the contact resistance between the conductive particles can be significantly reduced as compared with the case where the conductive particles are used for the conductive portion. It has been found that the thickness of the conductive sheet can be increased and a sheet having excellent conductivity in the thickness direction of the sheet can be obtained. Furthermore, this anisotropic conductive sheet is found to be excellent in heat resistance, durability and mechanical strength, and also excellent in adhesion to a semiconductor element, and as a magnetic fibrous filler in the fiber direction. It was also found that when a filler having high thermal conductivity was used, good thermal conductivity was also exhibited, and the present invention was completed.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems associated with the prior art as described above, wherein the magnetic fibrous filler is oriented in the sheet thickness direction while being oriented in the sheet thickness direction. It is an object of the present invention to provide a composite sheet having a convergence portion formed at a predetermined position. In addition, it is possible to increase the density of the conductive portion made of a fibrous filler, and the conductive portion has low resistance and high anisotropic conductivity in the thickness direction, and has heat resistance, durability, mechanical strength, and a semiconductor element. An object of the present invention is to provide a method of manufacturing an anisotropic conductive sheet having excellent adhesion and an anisotropic conductive sheet obtained by the manufacturing method. Another object of the present invention is to provide a thermally conductive sheet obtained by a similar manufacturing method.

[0008]

SUMMARY OF THE INVENTION A method for producing a composite sheet according to the present invention comprises:
A sheet-shaped composition comprising a fibrous filler (A) having magnetism and a binder (B) curable by heat and / or light is sandwiched between a pair of pole plates having a protruding pole face on the surface. A magnetic field parallel to the thickness direction of the sheet of the sheet composition is applied, and the fibrous filler having the magnetism is applied.
While orienting (A) in the thickness direction of the sheet, the fibrous filler (A) having magnetism is focused around the protruding surface of the pole plate, and the binder (B) is cured by heat and / or light. It is characterized by having

When the composite sheet is an anisotropic conductive composite sheet, the magnetic fibrous filler (A) is preferably a conductive filler having a noble metal adhered to the surface. When the composite sheet is a heat conductive composite sheet, the thermal conductivity in the fiber direction of the fibrous filler (A) having magnetism is preferably 100 W · m ⁻¹ · K ⁻¹ or more.
The fibrous filler (A) having magnetism is preferably a metal fiber having magnetism, or a fiber having a different magnetic susceptibility in a fiber axial direction and a fiber circumferential direction. The fibers having different magnetic susceptibilities in the fiber axis direction and the fiber circumferential direction are preferably carbon fibers. The magnetic fibrous filler (A) is preferably made of fibers having a magnetic substance adhered to the surface.

It is preferable that the projections of the pole plate having the projection-shaped magnetic pole surfaces on the surface are a plurality of strip-shaped projections arranged in parallel with each other or island-shaped projections arranged at a predetermined interval. Further, the pole plate having a protruding pole face on the surface may be a pole plate having a flat surface with concave portions filled with a non-magnetic material. Further, the pole plate having the protruding pole face on the surface is a flat pole plate in which the concave portion of the magnetic plate is filled with a non-magnetic material, and the surface of the pole plate further has a non-magnetic material. It may be a magnetic pole plate on which projections of a predetermined shape made of a magnetic material are fixed or adhered.

The composite sheet according to the present invention is a composite sheet containing a binder and a magnetic fibrous filler (A), wherein the magnetic fibrous filler (A) is contained in the binder. The fibrous filler (A) having magnetism oriented in the thickness direction of the composite sheet and oriented in the thickness direction of the composite sheet forms a plurality of converging portions. Further, in the composite sheet according to the present invention, it is preferable that the convergence portion of the fibrous filler (A) having magnetism oriented in the thickness direction of the composite sheet is formed in a band shape in the sheet surface direction, Focusing part of fibrous filler (A) having magnetism oriented in the thickness direction of
It may be formed in an island shape in the sheet surface direction.

[0012]

DETAILED DESCRIPTION OF THE INVENTION <Composite Sheet> The composite sheet according to the present invention comprises a binder and a magnetic fibrous filler.
(A) and wherein the fibrous filler (A) having the magnetism in the binder is oriented in the thickness direction of the composite sheet, and the magnetism oriented in the thickness direction of the composite sheet. The fibrous filler (A) has a plurality of converging portions, for example, a sheet having anisotropic conductivity or anisotropic thermal conductivity.

[0013] The composite sheet according to the present invention comprises a sheet-like composition comprising a fibrous filler (A) having magnetism and a binder (B) curable by heat and / or light. A magnetic field parallel to the thickness direction of the sheet composition, whereby the magnetic fibrous filler in the sheet is applied in the thickness direction of the sheet. It is obtained by orienting, focusing the fibrous filler near the protruding surface of the pole plate, and curing or semi-curing the binder with heat and / or light. When the fibrous filler having magnetism has high conductivity, it provides an effective method for producing an anisotropic conductive composite sheet, and when the fibrous filler has high heat conductivity in the fiber direction, heat is applied. An effective method for producing a conductive composite sheet is provided.

The details will be described below. In this specification, the term “orientation” means a case where the fibrous filler is oriented in a substantially constant direction. <Sheet composition for sheet> Fibrous filler having magnetism (A) As the `` fibrous filler having magnetism (A) '' according to the present invention, when a magnetic field is applied to the sheet composition according to the present invention, The fiber has a strength with a certain diameter that can be oriented substantially parallel to the direction of the magnetic field without refraction or breakage, and
It is a fibrous filler having a certain preferred aspect ratio, having resistance to heat applied as needed when forming or using the sheet according to the present invention (for example, having a melting point of 100 ° C. or more).

The fibrous filler having such magnetic properties
(A) includes metal fibers or fibers having different magnetic susceptibilities in the fiber axis direction and the fiber circumferential direction. When processed into a fibrous form, such metal fibers exhibit magnetic anisotropy derived from the shape, such as metals such as Fe, Co, and Ni, alloys thereof, and magnetism such as oxides thereof. Fibers.

The fibers having different magnetic susceptibilities in the fiber axis direction and the fiber circumferential direction are easily formed into a structure in which aromatic rings such as carbon fibers, aramid fibers, and fibers of polyparabenzazoles are arranged in parallel in the fiber direction. And fibers exhibiting essentially magnetic anisotropy. Of such fibers,
The carbon fiber can be selected from, for example, carbon fibers such as cellulose-based, PAN-based, and pitch-based carbon fibers depending on the type of the raw material. From the viewpoint of adding good thermal conductivity, pitch-based carbon fibers are used. It is preferable to use Among pitch-based carbon fibers, any of anisotropic carbon fibers and isotropic carbon fibers can be used as long as they exhibit high thermal conductivity. Examples of the aramid fiber include poly-p-phenylene terephthalamide, poly-m-phenylene isophthalamide, and the like. Of these, poly-p-phenylene terephthalamide fiber is preferable.
As a fiber of polyparabenzazoles, poly-p-
Phenylene benzobisoxazole, poly-p-phenylene benzobisthiazole and the like.
Poly-p-phenylene benzobisoxazole is preferred.

Further, fibers having different magnetic susceptibilities in the fiber axis direction and the fiber circumferential direction, such as the above-mentioned carbon fibers, aramid fibers, and polyparabenzazole fibers, or other fibers, such as Fe, Co, Ni, etc. The fibers to which the ferromagnetic substance is attached can also be used as the fibrous filler (A) according to the present invention. Examples of such fibers other than carbon fibers, aramid fibers, and polyparabenzazole fibers include known regenerated fibers and synthetic fibers. For example, regenerated fibers made of rayon and the like, and fats such as nylon 6, nylon 66, and the like. Group polyamide, polyethylene terephthalate (PE
T), synthetic fibers such as polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polypropylene (PP), polyvinyl chloride (PVC), polyethylene (PE), polyphenylene sulfide (PPS), ultra-high molecular weight polyethylene (UHMWPE), Fibers made of a polymer having a high heat resistance such as polyoxymethylene (POM), fibers made of a polymer having a so-called high elastic modulus and high strength such as wholly aromatic polyester and polyimide, and glass fibers are exemplified.

Among these, from the viewpoints of heat resistance, strength, etc., for example, wholly aromatic polyesters, polyimides, and glass fibers are preferable, and polyimide, wholly aromatic polyesters, and the like can be particularly preferably used. As such a fiber having a different magnetic susceptibility in the fiber axis direction and the fiber circumferential direction, such as carbon fiber and aramid fiber, or a ferromagnetic substance to be attached to other fibers, a magnetic field was applied by a method described later. In this case, as long as the magnetic layer exhibits a degree of magnetism that can be oriented in the direction of the magnetic field, it may be attached to the entire fiber surface in a layered manner or may be partially attached to the fiber surface without forming a layer.

As such a ferromagnetic material, for example,
Metals such as iron, cobalt and nickel or alloys composed of such metals are mentioned. Further, an intermetallic compound containing a ferromagnetic metal such as iron, cobalt and nickel or a metal compound such as a metal oxide of the metal is used. No.
The rate of adhesion of these ferromagnetic materials to the fibrous filler (the area ratio of adhesion) is not particularly limited, and as described above, by the method described below, the magnetism is such that it can be oriented in the direction of the magnetic field when a magnetic field is applied. It is not particularly limited if shown, for example,
It is preferable that the magnetic substance adhesion ratio (adhesion area ratio) on the surface of the fibrous filler is 30% or more, more preferably 50% or more, and particularly preferably 80% or more. The film thickness when the ferromagnetic material is deposited on the surface of the fibrous filler is, for example, 0.01 to 10 μm.
m, preferably 0.1-5 μm, particularly preferably 0.2
It is desirably about 1 μm.

The magnetic material can be attached to the fiber surface by, for example, electroless plating such as chemical plating. The shape of the magnetic fibrous filler (A) according to the present invention is preferably cylindrical. The diameter of the fiber according to the present invention is preferably 5 to 500 μm, more preferably 10 to 200 μm.
It is.

Such a “filamentous filler having magnetism”
(A) "is contained in the total volume of the sheet composition in a total volume of 1 to 20% by volume in the total volume of the sheet composition.
And more preferably 2 to 15
It is desirable for the amount to be in the range of% by volume, particularly preferably 2 to 10% by volume. When this ratio is less than 2% by volume, the thermal conductivity or conductivity in the thickness direction of the sheet obtained by curing the sheet composition may not be sufficiently increased,
On the other hand, if this proportion exceeds 20% by volume, the orientation tends to be insufficient because there is not enough space for the filler to move in the uncured binder in response to the magnetic field.

In the present invention, the magnetic fibrous filler (A) can be intensively distributed in a necessary portion and compared with the case where the magnetic fibrous filler (A) is distributed over the entire surface. Even if the content of (A) is small, it is possible to obtain a sheet giving sufficient anisotropic and thermal conductivity. (Conductive Composite Sheet, Thermal Conductive Composite Sheet) When the magnetic fibrous filler (A) according to the present invention has high conductivity in the fiber direction, it may be an anisotropic conductive composite sheet. Can, the magnetic fibrous filler (A)
However, when it has high thermal conductivity in the fiber direction, the resulting composite sheet can be a thermally conductive composite sheet.

When a heat conductive composite sheet is obtained, the above-mentioned magnetic filler (A) has a heat conductivity (W m ^-1 K ^-1 ) in the fiber direction of 100 or more, preferably 500 or more, particularly preferably 500 or more. Preferably, it is 1200 or more. Among the fibrous fillers, the fibrous filler for the heat conductive composite sheet is preferably a carbon fiber, an aramid fiber, a fiber of polyparabenzazoles, or a material obtained by attaching a magnetic substance to these. Further, metal fibers made of Fe, Co, and Ni can also be preferably used.

When a conductive composite sheet is obtained, the fibrous filler (A) having magnetism may be any of those exemplified above.
A metal that imparts conductivity may be attached to a metal fiber or a fiber having a different magnetic susceptibility in the fiber axis direction and the fiber circumferential direction. As such a material, a noble metal which is hardly oxidized in air and has high conductivity is preferable, and examples of such a noble metal include gold, silver, ruthenium, palladium, rhodium, osmium, iridium, and platinum. And preferably gold and silver. Such a noble metal may or may not be attached to the entire fiber surface in a film form, as long as it is attached to the fiber surface so that the anisotropic conductive composite sheet has conductivity. The noble metal can be attached to the fiber surface by, for example, electroless plating such as chemical plating. Further, since such a noble metal has an antioxidant effect, it is preferable to attach the noble metal to the outermost side. Examples of such fibers in which the magnetic substance and the noble metal adhere to the surface include:
For example, a fiber in which nickel as a magnetic substance is adhered to the surface of a carbon fiber, and a noble metal such as gold or silver is adhered to the surface of the carbon fiber is exemplified.

The adhesion rate (adhesion area ratio) of the noble metal to the fibrous filler is preferably at least 30%, more preferably at least 50%, particularly preferably at least 80%. In addition, as a film thickness when the noble metal is deposited on the surface of the fibrous filler, for example, 0.01 to 2 μm,
Preferably 0.02 to 1 μm, particularly preferably 0.05
It is desirable that the thickness be 0.5 μm.

As the magnetic fibrous filler (A) according to the present invention, those whose surface is further treated with a coupling agent such as a silane coupling agent can be used as appropriate. When the surface of the magnetic fibrous filler is further treated with a coupling agent, the adhesiveness between the fibrous filler and the binder is increased, and as a result, the obtained heat conductive composite sheet or conductive composite sheet is , High durability.

Binder (B) In the sheet composition for forming the composite sheet of the present invention, either a rubbery polymer or a resinous polymer can be used as the binder, and the binder may be used in a state before curing or semi-curing. A liquid binder can be preferably used.
Further, a photo-curable component and / or a thermo-curable component can be added to the binder, and the rubber-like polymer or the resin-like polymer as the binder component can be added to the photo-curable component and / or the thermo-curable component. It can also serve as a component.

The rubbery polymer, resinous polymer, photo-curable component and thermo-curable component used in the present invention will be described below. (Rubber-like polymer) Specific examples of the rubber-like polymer used in the present invention include conjugated diene-based rubbers such as polybutadiene, natural rubber, polyisoprene, SBR and NBR, hydrogenated products thereof, and styrene-butadiene block. Copolymers, block copolymers such as styrene isoprene block copolymers and their hydrogenated products, chloroprene, urethane rubber, polyester rubber, epichlorohydrin rubber, silicone rubber, ethylene propylene copolymer, ethylene propylene diene copolymer And the like. Among these, silicone rubber is particularly preferred from the viewpoint of moldability, weather resistance, heat resistance and the like.

Here, the silicone rubber will be described in more detail. It is preferable to use liquid silicone rubber as the silicone rubber. Liquid silicone rubber is
Any of a condensation type and an addition type may be used. Specific examples include dimethylsilicone raw rubber, methylphenylvinylsilicone raw rubber, and those containing a functional group such as a vinyl group, a hydroxyl group, a hydrosilyl group, a phenyl group, or a fluoro group. (Resinous polymer) As the resinous polymer according to the present invention,
Specifically, an epoxy resin, a phenol resin, a melamine resin, an unsaturated polyester resin, or the like can be used.
Of these, it is preferable to use an epoxy resin.

As the epoxy resin, those having two or more epoxy groups in one molecule are preferable. For example, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, Bisphenol AD type epoxy resin, alicyclic epoxy resin, or polyglycidyl (meth) acrylate, a copolymer of glycidyl (meth) acrylate and another copolymer monomer, and the like can be given. (Photo-curable component) As the photo-curable component contained in the binder according to the present invention, there are photo-radical polymerizable, photo-cationic polymerizable, coordinating photo-polymerizable, which is cured by ultraviolet light, electron beam,
Examples include monomers, oligomers, prepolymers or polymers that are photopolyaddition reactive. Such photocurable monomers, oligomers, prepolymers or polymers include (meth) acrylic compounds, vinyl ether-
Photo-radical polymerizable polymer such as maleic acid copolymer, thiol-
Preferred are photopolyaddition-reactive compounds such as ene-based compounds, and among them, (meth) acrylic-based compounds are particularly preferred. As the photocurable component according to the present invention, a monomer of a (meth) acrylic compound, which requires a short time for photocuring, is preferably used.

Specific examples of such photopolymerizable monomers, oligomers, prepolymers or monomers of (meth) acrylic compounds include monomers which can be derived from cyano group-containing vinyl compounds such as acrylonitrile and methacrylonitrile. , (Meth) acrylamide compounds and (meth) acrylic esters. Examples of the (meth) acrylamide compound include acrylamide, methacrylamide, N, N-dimethylacrylamide and the like, and these may be used alone or as a mixture.

The (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxyethyl (meth) acrylate, and phenyl (meth) acrylate. ) Monofunctional (meth) acrylates such as acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, and tricyclodecanyl (meth) acrylate; Used alone or as a mixture.

As the (meth) acrylic acid ester, a polyfunctional (meth) acrylate can be used. Examples of the polyfunctional (meth) acrylate include ethylene glycol di (meth) acrylate and diethylene glycol di (meth) acrylate. , Propylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth)
Acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9 -Nonanediol di (meth) acrylate,
1,10-decanediol di (meth) acrylate, glycerol di (meth) acrylate, bisphenol A
Ethylene oxide, diacrylate of propylene oxide adduct, bifunctional (meth) acrylate such as bisphenol A-diepoxy-acrylic acid adduct, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, glycerin tri ( And trifunctional (meth) acrylates such as (meth) acrylate.

Of these, particularly preferred are di (meth) acrylates such as diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate and glycerol di (meth) acrylate. . These may be used alone or as a mixture. (Thermosetting component) Examples of the thermosetting component that can be preferably used as the binder according to the present invention include monomers, oligomers, prepolymers and polymers having a functional group that is cured by heat.

As such functional groups, epoxy groups, hydroxyl groups, carboxyl groups, amino groups, isocyanate groups,
Examples thereof include a vinyl group and a hydrosilyl group, and an epoxy group, a vinyl group, and a hydrosilyl group are preferable from the viewpoint of reactivity. Monomers, oligomers having such functional groups,
Examples of the prepolymer or polymer include an epoxy compound, a urethane compound, and a silicone compound. Among these, it is preferable to use an epoxy compound and a silicone compound from the viewpoint of shortening the heat curing time. Further, the epoxy compound or the silicone compound has two or more epoxy groups, vinyl groups or hydrosilyl groups in the molecule. It is desirable to have.

The molecular weight of such an epoxy compound is not particularly limited, but is usually from 70 to 20,000.
Preferably, it is 300 to 5000, and specifically, various epoxy resins having a certain molecular weight or more, such as oligomers, prepolymers, or polymers of the epoxy compound, are preferably used. Specific examples of such an epoxy compound include, for example, the above-mentioned phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, alicyclic ring Examples include a formula epoxy resin, a polyglycidyl (meth) acrylate, and a copolymer of glycidyl (meth) acrylate with another copolymerized monomer.

When these phenol novolak type epoxy resins and the like are used as thermosetting components, they can also serve as resinous polymer components at the same time. Examples of the silicone-based compound include the above-described vinyl-containing silicone rubber, and a vinyl-containing silicone type is preferred as a silicone-based compound because of its reactivity with a hydrosilyl-containing compound used as a curing agent. When these silicone compounds are used as thermosetting components, they can also serve as rubbery polymer components at the same time.

A commercially available silicone compound which can also serve as a rubber-like polymer component is a room temperature-curable two-part addition type thermosetting liquid silicone rubber containing a hydrosilyl compound as a curing agent. Can be mentioned. These resins are used alone or as a mixture. (Combined Use of Photocurable Component and Thermosetting Component) As the binder according to the present invention, the photocurable component and the thermosetting component can be used in combination. In such a combined system, it is preferable that the thermosetting component does not cure under light curing conditions. As described above, when the photo-curable component and the thermo-curable component are used in combination as the binder according to the present invention, the mixing ratio (photo-curable component / thermo-curable component) is preferably from 80/20 to 20/20. /
80% by weight, more preferably 70/30 to 30/70
% By weight, particularly preferably 40/60 to 40/60% by weight
It is desirable that When the photocurable component and the thermosetting component are in such a range, the orientation of the fibrous filler in the composite sheet in a semi-cured state in the thickness direction of the sheet is sufficiently achieved, and When the sheet is cured, a composite sheet having excellent adhesiveness can be obtained.

As such a photo-curable component and a thermo-curable component according to the present invention, the combination of the (meth) acrylic compound and the epoxy compound may be used to form a semi-cured heat conductive composite sheet. This is preferred from the viewpoints of shortening the time and excellent adhesiveness. The method of mixing such a photocurable component and a thermosetting component is not particularly limited. For example, using the acrylic compound monomer as a photocurable component,
When using the epoxy resin as a thermosetting component,
The epoxy resin can be dissolved and mixed with the acrylic compound monomer.

As a component of the binder according to the present invention, a compound containing, in one molecule, a photocurable functional group and a thermosetting functional group that does not cure under photocuring conditions is used, and both components are used. You can also double. Examples of the compound containing such a photocurable functional group include the (meth) acrylic compound, and the thermosetting functional group include the epoxy group. Specific examples of the compound that can serve as both components include: Epoxy (meth) acrylamide such as glycidyl (meth) acrylamide, epoxy (meth) acrylate such as glycidyl (meth) acrylate, and 3,4-epoxycyclohexyl (meth) acrylate are exemplified.

Also, a reactive monomer having an unsaturated double bond can be contained as a binder component. Examples of such a reactive monomer include hydroxystyrene, isopropenylphenol, styrene, α-
Aromatic vinyl compounds such as methylstyrene, p-methylstyrene, chlorostyrene, p-methoxystyrene,
Hetero atom-containing alicyclic vinyl compounds such as vinylpyrrolidone and vinylcaprolactam. (Photoinitiator) In the composition for a composite sheet according to the present invention, depending on the type of radiation used for curing the photocurable component,
For example, in the case of ultraviolet curing, a photoinitiator and the like can be mixed.

Such a photoinitiator may be any as long as it cures the photocurable component contained in the sheet composition under the photocuring conditions according to the present invention. When a thermosetting component is used in combination, the photocurable component is cured and the thermosetting component is not cured, and a known photoinitiator can be used. Examples of such a photoinitiator include α-diketones such as benzyl and diacetyl; acyloins such as benzoin; acyloin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether; thioxanthon, 2,4- Diethylthioxanthone, thioxanthone-4-sulfonic acid, benzophenone, 4,4
(-Bis (dimethylamino) benzophenone, 4,4 '
Benzophenones such as -bis (diethylamino) benzophenone; acetophenone, p-dimethylaminoacetophenone, α, α′-dimethoxyacetoxybenzophenone, 2,2′-dimethoxy-2-phenylacetophenone, p-methoxyacetophenone, 2-methyl [4 −
(Methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-
Acetophenones such as (4-morpholinophenyl) -butan-1-one; quinones such as anthraquinone and 1,4-naphthoquinone; phenacyl chloride, tribromomethylphenylsulfone, and tris (trichloromethyl)
Halogen compounds such as -s-triazine; peroxides such as di-t-butyl peroxide; acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide. Also,
Commercial products include Irgacure 184, 651, 50
0,907, CG1369, CG24-61, Darocur 1116, 1173 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Lucirin LR8728, TPO (BA
SF) and Ubecryl P36 (UCB).

When the photocurable component and the thermosetting component are used together as a binder, the photocurable component contained in the sheet composition is a (meth) acrylic compound,
When the thermosetting component is an epoxy compound, a photoinitiator such as Irgacure 651 or Lucirin TPO, which has a high curing rate, can be preferably used. The amount of the photoinitiator used is preferably an appropriate amount in consideration of the actual curing speed, the balance with the pot life, and the like. Specifically, based on 100 parts by weight of the photocurable component, , 1 to 50 parts by weight, preferably in the binder.
It is particularly preferred that it is contained in a proportion of up to 30 parts by weight. 1
If the amount is less than 10 parts by weight, the sensitivity is easily reduced by oxygen. If the amount is more than 50 parts by weight, the compatibility is deteriorated or the storage stability is deteriorated.

A photoinitiator may be used in combination with such a photoinitiator. When a photoinitiator is used in combination, the initiation reaction is promoted as compared with the use of the photoinitiator alone,
The curing reaction can be performed efficiently. As such a photo-initiating aid, a commonly used photo-initiating aid can be used. Such photoinitiating aids include, for example, triethanolamine, methyldiethanolamine, triisopropanolamine, n-butylamine, N-
Aliphatic amines such as methyldiethanolamine and diethylaminoethyl (meth) acrylate, Michler's ketone, 4,4′-diethylaminophenone, ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate,
Isoamyl dimethylaminobenzoate and the like. (Thermosetting agent) A thermosetting agent may be mixed with the sheet composition according to the present invention in order to promote the thermosetting of the thermosetting component. As such a thermosetting agent according to the present invention, a known thermosetting agent can be used. Examples of such a thermosetting agent include amines, dicyandiamide, dibasic dihydrazide, imidazoles, hydrosilyl compounds, vinylsilyl compounds, and the like.

Specifically, polymethylenediamine, diethylenetriamine, dimethylaminopropylamine, bishexamethylenetriamine, diethylaminopropylamine, polyetherdiamine, 1,3-diaminocyclohexane, diaminodiphenylmethane, diaminodiphenylsulfone, 4,4 ′ -Bis (o-toluidine), m-phenylenediamine, 2-phenyl-4-methyl-5-hydroxymethylimidazole, block imidazole, polydimethylsiloxane containing both ends hydrosilyl group, polydimethylsiloxane containing both ends vinyl group, etc. Can be

It is preferable to use an appropriate amount of such a thermosetting agent in consideration of the balance between the actual curing speed and the pot life, but specifically, the thermosetting agent is a thermosetting agent. The binder is preferably contained in a proportion of 1 to 50 parts by weight, particularly preferably 1 to 30 parts by weight, based on 100 parts by weight of the active ingredient. The method of adding the photoinitiator and the thermosetting agent is not particularly limited, but it is preferable that the photoinitiator and the thermosetting agent are preliminarily mixed with a binder from the viewpoint of storage stability, prevention of uneven distribution of the catalyst when mixing the components, and the like. .

Other Additives In the present invention, the sheet composition may contain, if necessary, an inorganic filler such as ordinary silica powder, colloidal silica, airgel silica, and alumina. By including such an inorganic filler,
The thixotropic property at the time of uncuring is ensured, the viscosity is increased, and the dispersion stability in the composition of the fibrous filler (A) having magnetism is improved, and the strength of the sheet after curing or semi-curing is improved. Can be done. The amount of the inorganic filler used is not particularly limited, but if used in an excessively large amount, the orientation of the magnetic fibrous filler by the magnetic field may not be sufficiently achieved.

Preparation of Sheet Composition The sheet composition according to the present invention can be prepared by any of the conventionally known methods. For example, a binder, a magnetic fibrous filler, or if necessary, A method of mixing and kneading a photoinitiator, a thermosetting agent, an inorganic filler, and the like can be given.

The viscosity of the sheet composition of the present invention is preferably in the range of 10,000 to 1,000,000 cp at a temperature of 25 ° C., and such a sheet composition is preferably in the form of a paste. Is preferred. In order to form the sheet composition according to the present invention into a sheet shape, a conventionally known method can be employed, but a coating method, a roll rolling method, a casting method, or the like can be employed. <Magnetic Plate> The magnetic plate according to the present invention is a magnetic plate having a projecting magnetic pole surface on its surface so as to localize a magnetic field. Such a magnetic pole plate is preferably made of a strong metal such as iron, iron-nickel alloy, iron-cobalt alloy, nickel, and cobalt.

By the arrangement and the arrangement pattern of the projections of the magnetic pole plate, the fibrous filler having magnetism can be focused at a desired position in the sheet. For example, the semiconductor element can be mounted on the substrate. In addition, in the case of an anisotropic conductive composite sheet used for the inspection, in accordance with the fine electrode position of the semiconductor element, a convex portion is formed on the pole plate so that the fibrous filler with the noble metal attached to the surface is unevenly distributed. Preferably, it is provided. Further, in the case of the anisotropic conductive composite sheet, it is more preferable to provide the magnetic pole plate with a convex portion so that the fibrous filler having a high thermal conductivity in the fiber direction is unevenly distributed according to the shape of the heat generating portion.

The specific arrangement and arrangement pattern of such protrusions include, for example, a plurality of band-like protrusions arranged in parallel with each other, or island-like protrusions arranged at a predetermined interval. Further, such projections may be combined with various arrangement patterns. Further, in the pole plate having the protruding pole face according to the present invention, the recess can be filled with a non-magnetic material to make the pole plate surface flat. Further, in the magnetic pole plate, after the concave portion is filled with a non-magnetic material, a non-magnetic material having a projection of a predetermined shape can be further fixed or adhered to the surface thereof. By thus variously selecting the shape of the surface of the pole plate, it is possible to obtain surface projections of the composite sheet as desired. For example, when manufacturing an anisotropic conductive composite sheet used for mounting a semiconductor element on a substrate and inspecting the same, the composite sheet is formed into a sheet according to the bump shape of an electrode portion, a step between a resist and an electrode portion, and the like. One having a projection on the surface or one having no projection can be appropriately selected. Further, also in the heat conductive composite sheet, the surface shape can be appropriately selected according to the surface shape of the heating element. The non-magnetic material that can be filled in the concave portion may be a non-magnetic resin that is stable by heat, a magnetic field, and the like. For example, a polyimide resin,
Epoxy resins, phenolic resins and the like can be mentioned.

It is preferable that the magnetic pole plate according to the present invention having a projecting magnetic pole surface can be separated into a magnet portion such as an electromagnet and a magnetic plate having a projecting magnetic pole surface on the surface. According to this method, it is not necessary to use a specially shaped magnet, and by attaching a magnetic plate having a projecting pole face to the surface of a commercially available electromagnet having a parallel magnetic field, a projection having a desired pattern can be formed. A certain pole plate can be easily obtained. For example, when the magnetic plate is used for mounting a semiconductor element on a substrate and manufacturing an anisotropic conductive composite sheet used for the inspection, a projection may be formed according to a pattern of an electrode portion thereof. Although it is preferable, the processing method of the protrusion can be appropriately selected according to the arrangement of the electrode portions and the pitch between the electrodes. For example, for processing a magnetic plate corresponding to a semiconductor element having electrodes with a fine pitch of 100 μm or less, on a plate having magnetism such as an iron plate,
After patterning by a photolithographic process using a resist, it can be obtained by plating a magnetic material such as Fe or Ni. <Method of Manufacturing Composite Sheet> FIG. 1 is a three-dimensional view (a) of the composite sheet according to the present invention as viewed from the sheet surface side and bb thereof.
FIG. 4B is a sectional view taken along the line of FIG. As shown in FIG. 1 (a), the composite sheet 1 according to the present invention has a magnetic fibrous filler 3 in a binder 2 which is cured by heat and / or light.
The convergence portion is formed in an island shape at a predetermined interval while being oriented in the thickness direction of the sheet. Further, as shown in FIG. 1 (b), the fibrous filler 3 having magnetism is oriented in the thickness direction of the sheet and is focused at a predetermined position. The surface of the composite sheet is flat.

As shown in FIG. 3 (a), such a composite sheet is prepared by mixing a sheet composition 7 comprising a fibrous filler 5 having magnetism and a binder 6 before curing, as shown in FIG. 3 (b).
A magnetic plate 8 having island-like projections 12 arranged at predetermined intervals as shown in FIG. 1 and an electromagnet 10 between a pair of magnetic pole plates 11 in which recesses of the magnetic plate are filled with a nonmagnetic material 9. And applying a parallel magnetic field to the sheet composition 7 via the magnetic plate 8 and curing the sheet composition by heating or the like.

For example, as shown in FIG.
When a composite sheet is manufactured in the same manner as described above using a magnetic plate in which the belt-shaped protrusions 13 are arranged in parallel with each other as the magnetic plate 8, as shown in FIG.
Are oriented in the thickness direction of the sheet, and as shown in FIG.
The composite sheet 1 in which the fibrous fillers 4 having magnetism are formed in parallel band-shaped convergence portions at predetermined intervals.

Further, if the composite sheet is manufactured by the above-described method without filling the recesses of the magnetic plate 8 shown in FIG. A composite sheet having band-shaped or island-shaped projections can be manufactured. Further, a pole plate of a desired shape made of a non-magnetic material is further fixed or adhered to the surface of a pole plate 11 made of a magnetic plate 8 and a non-magnetic material 9 shown in FIG. Is used, a composite sheet having a desired surface shape can be manufactured.

The composite sheet thus produced is
When the magnetic fibrous filler (A) is a conductive filler having a noble metal adhered to the surface, the magnetic fibrous filler (A) becomes an anisotropic conductive composite sheet. If a fibrous filler having a high thermal conductivity is used (for example, 100 (Wm ^-1 · K ^-1 ) or more), a heat conductive composite sheet can be obtained.

The strength of the magnetic field applied to orient the magnetic fibrous filler in the sheet composition according to the present invention in the thickness direction of the sheet composition is preferably 500 to 50,000 gauss. Degree, more preferably 2
The magnetic field application time is preferably about 1 to 120 minutes, more preferably about 5 to 30000 Gauss.
It takes about 0 minutes. The application of the magnetic field may be performed at room temperature or may be performed by heating as needed.

The method of curing or semi-curing the sheet composition according to the present invention depends on the kind of the binder used and the required sheet performance and is not limited. For example, the epoxy resin is preferably used as a binder component, preferably from 80 to 180. ° C, more preferably 100-160
By heating in the range of ° C., the sheet composition can be cured. The heating method is not particularly limited, and a known method can be used, and the composition for a sheet may be cured using a usual heater or the like.
The heating time is not particularly limited, and is preferably in a range of about 5 to 120 minutes.

In the composite sheet according to the present invention obtained by such a production method, the fibrous filler (A) may be exposed or present on the surface of the composite sheet. Further, such a fibrous filler (A) may be exposed on the surface of the composite sheet when the composite sheet is compressed in its thickness direction. In this specification, the term “exposed” to the surface of the composite sheet means that the end of the fibrous filler is present on the surface of the sheet, and for example, the composite sheet surface is bonded to the surface of another member. Sometimes, it means that the mating member and the fibrous filler can be in contact with each other.

The method of compressing the composite sheet can be selected according to the use of the sheet and the like, and is not particularly limited. For example, a constant weight is applied in the thickness direction of the sheet or a constant distortion is applied to the sheet thickness. It can be done by giving from outside. Further, the sheet to be formed can be compressed by utilizing the curing shrinkage caused by curing the composition capable of forming the sheet according to the present invention from an uncured liquid state. Further, the sheet in a semi-cured state can be compressed by thermocompression bonding to cure the sheet under pressure.

[0061]

According to the production method of the present invention, the fibrous filler having magnetism is oriented in the thickness direction of the sheet, and the fibrous filler having magnetism oriented in the thickness direction of the sheet forms a plurality of bundles. For example, when the fibrous filler has high conductivity, it is possible to increase the density of the conductive portion while forming the conductive portion of the anisotropic conductive composite sheet at a predetermined position. Obtaining an anisotropically conductive composite sheet that is possible, has a low resistance in the conductive part, has high anisotropic conductivity in the thickness direction, and has excellent heat resistance, durability, mechanical strength, and adhesion to a semiconductor element. Can be. Further, a heat conductive composite sheet can be obtained by the same manufacturing method.

[0062]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by these Examples.

[0063]

Example 1 [Production of anisotropic conductive composite sheet] (1) Preparation of composition for anisotropic conductive composite sheet After electroless plating nickel on the surface so as to have an average film thickness of 0.8 µm, A carbon fiber having an average diameter of 10 μm and an average length of 100 μm obtained by electrolessly plating silver on the surface so as to have an average film thickness of 0.1 μm is applied to a two-pack type addition-type thermosetting liquid silicone rubber (viscosity of 10 P) by 5%. The volume fraction (%) was added and mixed in a vacuum for 30 minutes to obtain a composition for an anisotropic conductive composite sheet. (2) Magnetic plate with projections on the surface Using a 50 μm thick resist on a 5 mm thick iron plate,
An opening of 70 μmφ was arranged on a straight line at a pitch of 120 μm and patterned. After the opening was plated with Ni as a magnetic pole, the surface was trimmed to produce a magnetic plate for molding an anisotropic conductive composite sheet. In addition, since the magnetic material plate was used by aligning the upper and lower sides, pin holes for positioning were formed at four corners based on the production pattern. (3) Production of anisotropic conductive composite sheet The above composition was placed in two PET films (50 μm each) placed in parallel via a 0.1 mm thick spacer.
) To obtain a sheet-like composition. Next, the sheet-shaped composition is sandwiched between the positioned upper and lower magnetic materials,
Use an electromagnet so that the lines of magnetic force pass in the thickness direction.
After processing at a magnetic field strength of 000 gauss for 20 minutes, the mixture was heated to 100 ° C. while applying the pressure, and the thickness of the cured state was increased to 0.
A 1 mm anisotropic conductive composite sheet was obtained. The anisotropic conductive performance in the thickness direction of the anisotropic conductive composite sheet was evaluated by the following method.

<Anisotropic Conductivity Test> (1) Evaluation of Conductivity in Thickness Direction The above-described anisotropic conductive composite sheet was placed on a test substrate in which 1,000 electrodes of 70 μmφ were linearly arranged at a pitch of 120 μm. N, with gold plating on the surface
After stacking the i-plates, the weight of the anisotropic conductive composite sheet was evaluated by measuring the resistance between the electrodes by applying a light weight with a weight, and measuring the resistance between the electrodes. (2) Insulation evaluation in the direction perpendicular to the thickness direction In place of a Ni plate with a gold-plated surface, the same configuration as described above except that a resinous insulation plate is stacked, and the resistance between adjacent electrodes is measured. Thereby, the insulating property in the direction perpendicular to the thickness direction of the anisotropic conductive composite sheet was evaluated.

The thermal conductivity was evaluated by the following method. <Thermal Conductivity Test> FIG. 4 shows a method for evaluating the thermal diffusivity of a thermally conductive composite sheet by a thermal alternating current method. The thermal diffusivity (α) is calculated based on the relationship shown in Expression 2, and the thermal conductivity in the thickness direction of the heat conductive composite sheet is calculated from the values of the heat capacity and density separately obtained by a conventional method based on Expression 1 below. (Λ) can be obtained.

As shown in FIG. 4, the system for measuring the phase difference (△ θ) of the temperature change by the thermal alternating current method comprises a function generator 17, a lock-in amplifier 18, a personal computer 19, a sample 14, electrodes 15 and 16. .
By sandwiching both surfaces of sample 14 between electrodes 15 and 16 (a metal thin film provided on a glass plate by sputtering), and applying an AC voltage to one electrode 15, sample 1
4 was heated, the temperature change was detected from the resistance change of the other electrode 16, and as shown in FIG. 5, the phase difference (Δθ) of the temperature change (ΔT) was measured from the response delay. The thermal diffusivity (α) was determined based on Equation 2, and the conductivity (λ) was determined based on Equation 1. In addition, under normal conditions, the measurement was performed under the condition that the sample was not compressed as much as possible.

[0067]

(Equation 1)

[0068]

(Equation 2)

[0069]

Example 2 (1) Preparation of Composition for Anisotropically Conductive Composite Sheet After electrolessly plating nickel on the surface so as to have an average film thickness of 0.8 μm, the composition was further adjusted to have an average film thickness of 0.1 μm. A carbon fiber having an average diameter of 10 μm and an average length of 200 μm obtained by electrolessly plating gold on the surface is coated on a bisphenol A type epoxy resin (EP828, Yuka Shell Epoxy Co., Ltd.)
10% by volume to a binder containing 10% by weight of an imidazole-based curing agent (2P4MHZ-PW, manufactured by Shikoku Chemicals Co., Ltd.), and mixed in a vacuum for 30 minutes. A composition for an electroconductive composite sheet was obtained. (2) Magnetic plate with protrusions on the surface A 5 mm thick iron plate is machined to a depth of 100 μm, 70
The grooves having a width of μm were arranged on a straight line at a pitch of 120 μm. After the grooves were filled with a liquid epoxy resin, they were cured by heating, and then the surface was flattened to prepare a magnetic plate for molding an anisotropic conductive composite sheet. In addition, since the magnetic material plate was used by aligning the upper and lower sides, pin holes for positioning were formed at four corners based on the production pattern. (3) Production of an anisotropic conductive composite sheet This composition was placed on two PET films (50 μm each) placed in parallel via a 0.2 mm thick spacer.
) To obtain a sheet-like composition. Next, the sheet-shaped composition is sandwiched between the positioned upper and lower magnetic materials,
After processing at room temperature with a magnetic field strength of about 4000 gauss for 20 minutes at room temperature by an electromagnet so that lines of magnetic force pass in the thickness direction,
While the application was continued, the mixture was heated to 100 ° C. to obtain a cured anisotropic conductive composite sheet having a thickness of 0.2 mm.

The anisotropic conductivity of the obtained anisotropic conductive composite sheet was evaluated except that a test substrate in which 1,000 rectangular electrodes of 70 × 300 μm were arranged in a straight line at a pitch of 120 μm was used as a test substrate. Was performed in the same manner as in Example 1. The thermal conductivity was evaluated in the same manner as in Example 1.

[0071]

Example 3 [Production of anisotropic conductive composite sheet] (1) Preparation of composition for anisotropic conductive composite sheet After electroless plating nickel on the surface so as to have an average film thickness of 0.8 µm, A carbon fiber having an average diameter of 10 μm and an average length of 200 μm obtained by electrolessly plating silver on the surface so as to have an average film thickness of 0.4 μm is applied to a two-pack type addition-type thermosetting liquid silicone rubber (viscosity 10 P) by 5%. The volume fraction (%) was added and mixed in a vacuum for 30 minutes to obtain a composition for an anisotropic conductive composite sheet. (2) Magnetic plate with projections on the surface Using a 50 μm thick resist on a 5 mm thick iron plate,
An opening of 70 μmφ was arranged on a straight line at a pitch of 120 μm and patterned. After the opening was plated with Ni as a magnetic pole, the surface was flattened to obtain a smooth magnetic plate. Further, a resist having a thickness of 50 μm was applied thereon,
, And the openings having a diameter of 70 μm were arranged on a straight line at a pitch of 120 μm again and patterned to obtain a magnetic plate. In addition, since the magnetic material plate was used by aligning the top and bottom, positioning pin holes were formed at four corners based on the production pattern. (3) Production of an anisotropic conductive composite sheet The above composition was placed in two PET films (50 μm each) placed in parallel via a 0.2 mm thick spacer.
) To obtain a sheet-like composition. Next, the sheet-shaped composition is sandwiched between the positioned upper and lower magnetic materials,
Use an electromagnet so that the lines of magnetic force pass in the thickness direction.
After processing at a magnetic field strength of 000 gauss for 20 minutes, the coating was heated to 100 ° C. while the application was continued, so that the cured state had a thickness of 0.1 mm.
A 1 mm anisotropic conductive composite sheet was obtained. The anisotropic conductive performance in the thickness direction of the anisotropic conductive composite sheet was evaluated by the following method.

The anisotropic conductivity of the obtained anisotropically conductive composite sheet was evaluated by using a 70 μmφ electrode as a test substrate.
The test was performed in the same manner as in Example 1, except that 1000 test substrates were linearly arranged at a pitch of 0 μm and the periphery of the electrodes was covered with a 50 μm thick resist.
The thermal conductivity was evaluated in the same manner as in Example 1.

[0073]

Comparative Example 1 Example 1 was repeated except that a cured sheet was obtained by directly sandwiching the sheet-like composition between electromagnets and applying a magnetic field without using a magnetic plate having protrusions on the surface.
In the same manner as in the above, a sheet was obtained. Evaluation of anisotropic conductivity and thermal conductivity was performed in the same manner as in Example 1.

[0074]

Comparative Example 2 An anisotropic conductive composite sheet was obtained in the same manner as in Example 1 except that silver was not adhered to the surface. Evaluation of anisotropic conductivity and thermal conductivity was performed in the same manner as in Example 1.

[0075]

Comparative Example 3 A sheet was obtained in the same manner as in Example 1 except that a cured sheet was obtained without applying a magnetic field. Evaluation of anisotropic conductivity and thermal conductivity was performed in the same manner as in Example 1. (Evaluation) Table 1 shows the conductivity of the sheets of Examples 1 and 2 and Comparative Examples 1 to 3 in the thickness direction and the direction perpendicular to the thickness direction. In addition, regarding the resistance in the thickness direction, 場合 when the resistance is 1Ω or less, Δ when the resistance is 1-10Ω, × when the resistance is 10 ohms or more.
And Regarding the resistance in the direction perpendicular to the thickness, a case of 1 MΩ or more was evaluated as ○, and a case of 1 MΩ or less was evaluated as ×.

The thermal conductivity of the sheets obtained in Examples 1 and 2 and Comparative Examples 1 to 3 was less than 5 times the thermal conductivity of the sheet obtained in Comparative Example 3; A sample of 5 times or more and less than 20 times was evaluated as Δ, and a sample of 20 times or more was evaluated as ○.
The results are shown in Table 1.

[0077]

[Table 1]

[Brief description of the drawings]

FIG. 1 (a) shows a composite sheet in which a magnetic fibrous filler is oriented in the thickness direction of the sheet and the fibrous filler forms an island-shaped convergence portion when viewed from the sheet surface side. FIG. FIG. 1 (b) is a schematic cross-sectional view taken along the line bb of a composite sheet in which magnetic fibrous fillers are oriented in the thickness direction of the sheet and the fibrous fillers are locally distributed in an island shape. FIG.

FIG. 2 (a) shows a composite sheet in which magnetic fibrous fillers are oriented in the thickness direction of the sheet, and the fibrous fillers form a band-shaped convergence section from the sheet surface side. It is a three-dimensional schematic diagram. FIG. 2B is a schematic cross-sectional view taken along line bb of a composite sheet in which the fibrous filler having magnetism is oriented in the thickness direction of the sheet and the fibrous filler is locally distributed in a strip shape. It is.

FIG. 3A is a schematic diagram of a cross section of a composite sheet manufacturing apparatus. FIG. 3B is a schematic view of a magnetic plate used in the manufacturing apparatus. FIG. 3C is a schematic view of a magnetic plate used in the manufacturing apparatus.

FIG. 4 is a diagram showing a method of measuring thermal conductivity by a thermal alternating current method.

FIG. 5 is a diagram showing a phase difference of a temperature change in a method of measuring thermal conductivity by a thermal alternating current method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Composite sheet 2 Binder 3 Magnetic fibrous filler oriented in the thickness direction of the sheet and converged in an island shape in the sheet surface direction 4 Magnetized in a band shape in the sheet surface direction and oriented in the thickness direction of the sheet surface Fibrous filler having 5 Fibrous filler having magnetism 6 Binder before curing 7 Composition for sheet 8 Magnetic plate 9 Nonmagnetic material 10 Electromagnet 11 Magnetic pole plate 12 Island projection 13 Band projection 14 Sample 15 Electrode 16 Electrode 17 Function generator 18 Lock-in amplifier 19 PC

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hozumi Sato 2-11-24 Tsukiji, Chuo-ku, Tokyo FSR term in JSR Corporation (reference) 5E051 CA04 5G307 HA02 HB03 HC01

Claims (12)

[Claims] 1. A sheet-like composition comprising a fibrous filler (A) having magnetism and a binder (B) curable by heat and / or light is applied between a pair of pole plates having a protruding pole face on the surface. While applying a magnetic field parallel to the thickness direction of the sheet of the sheet-shaped composition, while orienting the magnetic fibrous filler (A) in the sheet thickness direction, the magnetic fibrous filler ( A) is focused around the protruding surface of the pole plate, and the binder (B)
A composite sheet, which is cured by heat and / or light. 2. The magnetic fibrous filler (A)
2. The method for producing an anisotropic conductive composite sheet according to claim 1, wherein is a conductive filler having a noble metal adhered to the surface. 3. The magnetic fibrous filler (A)
The method for producing a thermally conductive composite sheet according to claim 1, wherein the thermal conductivity in the fiber direction is 100 W · m ^-1 · K ^-1 or more. 4. The fibrous filler having magnetic properties (A)
Is a metal fiber having magnetism, or a fiber having a different magnetic susceptibility in a fiber axial direction and a fiber circumferential direction, the method for producing a composite sheet according to any one of claims 1 to 3. 5. The method according to claim 4, wherein the fibers having different magnetic susceptibilities in the fiber axis direction and the fiber circumferential direction are carbon fibers. 6. The magnetic fibrous filler (A)
6. A method for producing a composite sheet according to claim 1, wherein the fiber comprises a fiber having a magnetic substance adhered to a surface thereof. 7. The projection of the pole plate having a projection-shaped magnetic pole surface on its surface is a plurality of strip-shaped projections arranged in parallel with each other or island-shaped projections arranged at a predetermined interval. The method for producing a composite sheet according to claim 1. 8. A magnetic pole plate having a protruding magnetic pole surface on the surface, wherein the concave portion of the magnetic pole plate is filled with a nonmagnetic material, and the surface is a flat magnetic pole plate. 8. The method for producing a composite sheet according to item 7. 9. A magnetic pole plate having a protruding magnetic pole surface on its surface, wherein the surface of the magnetic plate in which a concave portion of the magnetic plate is filled with a non-magnetic material is a planar magnetic plate, The method according to any one of claims 1 to 8, wherein the magnetic sheet is a magnetic pole plate to which projections of a predetermined shape made of a nonmagnetic material are fixed or adhered. 10. A composite sheet containing a binder and a fibrous filler (A) having magnetism, wherein the fibrous filler (A) having magnetism is oriented in a thickness direction of the composite sheet in the binder. A composite sheet, wherein the fibrous filler (A) having magnetism oriented in the thickness direction of the composite sheet forms a plurality of converging portions. 11. A convergence portion of a fibrous filler (A) having magnetism oriented in a thickness direction of the composite sheet is formed in a belt shape in a sheet surface direction.
The composite sheet according to 0. 12. The composite sheet according to claim 1, wherein the convergence portion of the fibrous filler (A) having magnetism oriented in the thickness direction is formed in an island shape in the sheet surface direction.
The composite sheet according to 0.