JP2012178342A - Anisotropic conductive material and connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anisotropic conductive material capable of enhancing conduction reliability when used for connection between electrodes in a connection structure, and also to provide the connection structure using the anisotropic conductive material.SOLUTION: The anisotropic conductive material contains a curable compound capable of being cured by the irradiation with light or the application of heat; at least one of a photopolymerization initiator and a thermosetting agent; a conductive particle; and a filler of which the particle size is 10 nm or more and 1,000 nm or less. In the whole 100 wt.% of the filler of which the particle size is 10 nm or more and 1,000 nm or less, the content of the filler of which the particle size is 10 nm or more and less than 300 nm is 10 wt.% or more and 65 wt.% or less, and the content of the filler of which the particle size is 300 nm or more and 1,000 nm or less is 35 wt.% or more and 90 wt.% or less.

Description

  The present invention relates to an anisotropic conductive material including a plurality of conductive particles, and for example, can be used for electrical connection between electrodes of various connection target members such as a flexible printed board, a glass substrate, and a semiconductor chip. The present invention relates to an isotropic conductive material and a connection structure using the anisotropic conductive material.

  Pasty or film-like anisotropic conductive materials are widely known. In the anisotropic conductive material, a plurality of conductive particles are dispersed in a binder resin or the like.

  Specifically, the anisotropic conductive material includes a connection between the IC chip and the flexible printed circuit board, a connection between the IC chip and the circuit board having the ITO electrode, and a circuit board having the ITO electrode and the flexible printed circuit board. It is used for connection. For example, after an anisotropic conductive material is arranged between the electrode of the IC chip and the electrode of the circuit board, these electrodes can be connected by heating and pressurizing.

  As an example of the anisotropic conductive material, the following Patent Document 1 includes an epoxy resin having an average of 1.2 or more epoxy groups in one molecule, rubber-like polymer fine particles, a thermal latent epoxy curing agent, An anisotropic conductive paste containing high softening point polymer fine particles and conductive particles is disclosed. The rubbery polymer fine particles have a softening point of 0 ° C. or lower and a primary particle size of 5 μm or lower. The high softening point polymer fine particles have a softening point of 50 ° C. or more and a primary particle diameter of 2 μm or less. The conductive particles have an average particle size of 5 to 15 μm, a maximum particle size of 20 μm or less, and a minimum particle size of 0.1 μm or more. Patent Document 1 describes that an inorganic filler may be used, and silica and alumina are used as the inorganic filler in the examples.

Japanese Patent No. 3904798

  For example, when an electrode of a semiconductor chip and an electrode of a glass substrate are electrically connected by a conventional anisotropic conductive material as described in Patent Document 1, for example, a different particle containing conductive particles is formed on the glass substrate. An isotropic conductive material is disposed. Next, the semiconductor chips are stacked, and heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.

  The anisotropic conductive material described in Patent Document 1 has a problem that the rubbery polymer fine particles and the high softening point polymer fine particles are easily sandwiched between the conductive particles and the electrode. When these fine particles are sandwiched between the conductive particles and the electrode, poor conduction occurs or the connection resistance increases. Therefore, there is a problem that conduction reliability in the obtained connection structure is lowered.

  Furthermore, in the conventional anisotropic conductive material, in the connection structure using the anisotropic conductive material for connection between the electrodes, when the thermal shock such as a thermal cycle is applied, the anisotropic conductive material is cured. Cracks may occur in the material layer. That is, a connection structure using a conventional anisotropic conductive material may have low thermal shock characteristics.

  An object of the present invention is to provide an anisotropic conductive material capable of enhancing conduction reliability when used for connection between electrodes in a connection structure, and a connection structure using the anisotropic conductive material. That is.

  A limited object of the present invention is to provide an anisotropic conductive material capable of enhancing the thermal shock resistance of a connection structure against a thermal shock such as a cold cycle, and a connection structure using the anisotropic conductive material. That is.

  According to a wide aspect of the present invention, a curable compound curable by light irradiation or heat application, at least one of a photopolymerization initiator and a thermosetting agent, conductive particles, and a particle size of 10 nm. The filler (A) containing a filler (X) having a particle size of 1000 nm or less and having a particle size of 10 nm or more and less than 300 nm in 100% by weight of the whole filler (X) having a particle size of 10 nm or more and 1000 nm or less. The content of filler is 10 wt% or more and 65 wt% or less, and the content of the filler (B) having a particle diameter of 300 nm or more and 1000 nm or less is 35 wt% or more and 90 wt% or less. A conductive material is provided.

  The average particle size of the conductive particles is preferably 1 μm or more and 100 μm or less.

  In a specific aspect of the anisotropic conductive material according to the present invention, a filler having a particle diameter of 300 nm or more and less than 600 nm in 100% by weight of the whole filler (X) having a particle diameter of 10 nm or more and 1000 nm or less ( The content of B1) is 10% by weight or less.

  In another specific aspect of the anisotropic conductive material according to the present invention, a filler having a particle size of 600 nm or more and 1000 nm or less in 100% by weight of the whole filler (X) having a particle size of 10 nm or more and 1000 nm or less. The content of (B2) is 30% by weight or more.

  In still another specific aspect of the anisotropic conductive material according to the present invention, the filler (A) having a particle diameter of 10 nm or more and less than 300 nm includes core-shell particles.

  In another specific aspect of the anisotropic conductive material according to the present invention, the filler (A) having a particle diameter of 10 nm or more and less than 300 nm includes inorganic particles.

  In still another specific aspect of the anisotropic conductive material according to the present invention, the filler (A) having a particle diameter of 10 nm or more and less than 300 nm includes both core-shell particles and inorganic particles.

  In another specific aspect of the anisotropic conductive material according to the present invention, the filler (B2) having a particle diameter of 600 nm or more and 1000 nm or less is a hydrophobized filler.

  The total content of the filler (X) having a particle diameter of 10 nm or more and 1000 nm or less with respect to 100 parts by weight of the curable compound is preferably 15 parts by weight or more and 75 parts by weight or less.

  The connection structure according to the present invention includes a first connection target member, a second connection target member, and a connection part that electrically connects the first and second connection target members. The connecting portion is formed by curing an anisotropic conductive material configured according to the present invention.

An anisotropic conductive material according to the present invention includes a curable compound curable by light irradiation or heat application, at least one of a photopolymerization initiator and a thermosetting agent, conductive particles, and a particle diameter. And filler (X) having a particle diameter of 10 nm or more and 1000 nm or less, and the filler having a particle diameter of 10 nm or more and less than 300 nm in 100% by weight of the whole filler (X) having a particle diameter of 10 nm or more and 1000 nm or less Since the content of (A) is 10% by weight or more and 65% by weight or less, and the content of the filler (B) having a particle diameter of 300 nm or more and 1000 nm or less is 35% by weight or more and 90% by weight or less. When the anisotropic conductive material according to the present invention is used for connection between electrodes in a connection structure, conduction reliability can be improved.

FIG. 1 is a front sectional view schematically showing a connection structure using an anisotropic conductive material according to an embodiment of the present invention. 2A to 2C are front cross-sectional views for explaining each step of obtaining a connection structure using the anisotropic conductive material according to the embodiment of the present invention.

  Hereinafter, the present invention will be described in detail.

  An anisotropic conductive material according to the present invention includes a curable compound curable by light irradiation or heat application, at least one of a photopolymerization initiator and a thermosetting agent, conductive particles, and a particle diameter. And filler (X) that is 10 nm or more and 1000 nm or less. When the curable compound is curable by light irradiation, it preferably contains a photopolymerization initiator. When the curable compound is curable by application of heat, it preferably contains a thermosetting agent. In the case where the curable compound can be cured by both irradiation with light and application of heat, it is preferable to include both a photopolymerization initiator and a thermosetting agent.

  In the anisotropic conductive material according to the present invention, the content of the filler (A) having a particle diameter of 10 nm or more and less than 300 nm in 100% by weight of the whole filler (X) having a particle diameter of 10 nm or more and 1000 nm or less. Is 10 wt% or more and 65 wt% or less, and the content of the filler (B) having a particle size of 300 nm or more and 1000 nm or less is 35 wt% or more and 90 wt% or less.

  When the anisotropic conductive material according to the present invention is used for connection between the electrodes in the connection structure by adopting the above-described configuration including the specific filler (X) as described above, between the electrode and the conductive particles. It becomes difficult for the filler (X) to be sandwiched between the two. For this reason, the conduction | electrical_connection reliability in the connection structure obtained can be improved. Furthermore, the adoption of the above configuration improves the dispersibility of the filler in the anisotropic conductive material. As a result, it is possible to improve the thermal shock resistance against thermal shock such as a cooling / heating cycle of the obtained connection structure. For example, cracks are less likely to occur in the cured anisotropic conductive material.

  The anisotropic conductive material according to the present invention may be a paste-like anisotropic conductive paste or a film-like anisotropic conductive film. The anisotropic conductive material according to the present invention is preferably an anisotropic conductive paste. In this case, the filler is more difficult to be sandwiched between the electrode and the conductive particles. Therefore, the conduction reliability in the obtained connection structure can be improved.

  Hereinafter, first, the details of each component contained in the anisotropic conductive material according to the present invention will be described.

(Curable compound)
The curable compound contained in the anisotropic conductive material according to the present invention can be cured by light irradiation or heat application. The curable compound is not particularly limited. A conventionally known curable compound can be used as the curable compound. As for the said sclerosing | hardenable compound, only 1 type may be used and 2 or more types may be used together.

  Examples of the curable compound include light and thermosetting compounds, photocurable compounds, and thermosetting compounds. The light and thermosetting compounds have photocuring properties and thermosetting properties. The said photocurable compound has photocurability, for example, and does not have thermosetting. The said thermosetting compound does not have photocurability, for example, and has thermosetting.

  It is preferable that the said curable compound contains light and a thermosetting compound, or contains both a photocurable compound and a thermosetting compound.

[Thermosetting compound]
Examples of the thermosetting compound include epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenolic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimide compounds. As for the said thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of easily controlling the curing of the anisotropic conductive material or further improving the conduction reliability of the connection structure, the thermosetting compound is a thermosetting compound having an epoxy group or a thiirane group. It is preferable that The compound having an epoxy group is an epoxy compound. The compound having a thiirane group is an episulfide compound. From the viewpoint of allowing thermosetting to proceed more rapidly, the thermosetting compound is preferably an episulfide compound.

  Since the episulfide compound has a thiirane group instead of an epoxy group, it can be cured quickly at a low temperature. That is, the episulfide compound having a thiirane group can be cured at a lower temperature derived from the thiirane group as compared with the epoxy compound having an epoxy group.

  The epoxy compound and the episulfide compound preferably have an aromatic ring. Examples of the aromatic ring include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, tetracene ring, chrysene ring, triphenylene ring, tetraphen ring, pyrene ring, pentacene ring, picene ring, and perylene ring. Especially, it is preferable that the said aromatic ring is a benzene ring, a naphthalene ring, or an anthracene ring.

  From the viewpoint of curing more rapidly at a low temperature, the episulfide compound is an episulfide compound having a structure represented by the following formula (1-1), (2-1), (3), (7) or (8). It is preferable that it is an episulfide compound having a structure represented by the following formula (1-1), (2-1) or (3). In the following formula (1-1), the bonding sites of the six groups bonded to the benzene ring are not particularly limited. In the following formula (2-1), the bonding sites of the eight groups bonded to the naphthalene ring are not particularly limited.

  In said formula (1-1), R1 and R2 represent a C1-C5 alkylene group, respectively. Of the four groups R3, R4, R5 and R6, 2 to 4 groups represent hydrogen. The group which is not hydrogen among R3, R4, R5 and R6 represents a group represented by the following formula (4). All four groups of R3, R4, R5 and R6 may be hydrogen. One or two of the four groups of R3, R4, R5 and R6 is a group represented by the following formula (4), and among the four groups of R3, R4, R5 and R6 The group that is not a group represented by the following formula (4) may be hydrogen.

  In said formula (4), R7 represents a C1-C5 alkylene group.

  In said formula (2-1), R51 and R52 represent a C1-C5 alkylene group, respectively. Of the 6 groups of R53, R54, R55, R56, R57 and R58, 4 to 6 groups represent hydrogen. The group which is not hydrogen among R53, R54, R55, R56, R57 and R58 represents a group represented by the following formula (5). All of the six groups of R53, R54, R55, R56, R57 and R58 may be hydrogen. One or two of the six groups of R53, R54, R55, R56, R57 and R58 are groups represented by the following formula (5), and R53, R54, R55, R56, R57 and R58. Of these, a group that is not a group represented by the following formula (5) may be hydrogen.

  In said formula (5), R59 represents a C1-C5 alkylene group.

  In said formula (3), R101 and R102 represent a C1-C5 alkylene group, respectively. Six to eight groups out of the eight groups of R103, R104, R105, R106, R107, R108, R109 and R110 represent hydrogen. The group which is not hydrogen among R103, R104, R105, R106, R107, R108, R109 and R110 represents a group represented by the following formula (6). All of the eight groups of R103, R104, R105, R106, R107, R108, R109 and R110 may be hydrogen. One or two of the eight groups of R103, R104, R105, R106, R107, R108, R109 and R110 are groups represented by the following formula (6), and R103, R104, R105, R106 , R107, R108, R109 and R110, which is not a group represented by the following formula (6), may be hydrogen.

  In said formula (6), R111 represents a C1-C5 alkylene group.

  In said formula (7), R1 and R2 represent a C1-C5 alkylene group, respectively.

  In said formula (8), R3 and R4 represent a C1-C5 alkylene group, respectively.

  The episulfide compound having a structure represented by the above formulas (1-1) and (2-1) is preferably an episulfide compound having a structure represented by the following formulas (1) and (2).

  In the above formula (1), R1 to R6 are the same groups as R1 to R6 in the above formula (1-1).

  In the above formula (2), R51 to R58 are the same groups as R51 to R58 in the above formula (2-1).

  The anisotropic conductive material may include a modified phenoxy resin having a thiirane group in which an epoxy group of the phenoxy resin is converted into a thiirane group as an episulfide compound. Using a sulfurizing agent, the epoxy group of the phenoxy resin can be converted to a thiirane group by a conventionally known method.

  The “phenoxy resin” is generally a resin obtained by reacting, for example, an epihalohydrin and a divalent phenol compound, or a resin obtained by reacting a divalent epoxy compound with a divalent phenol compound. .

In the above reaction for obtaining a phenoxy resin, by using a compound having a thiirane group obtained by converting the epoxy group of the compound having an epoxy group into a thiirane group instead of the compound having an epoxy group as a raw material of the phenoxy resin, The phenoxy resin which has can be obtained. Furthermore, a phenoxy resin having a thiirane group can also be obtained by preparing a phenoxy resin having an epoxy group and converting the epoxy group of the phenoxy resin having an epoxy group into a thiirane group.

  The epoxy compound is not particularly limited. A conventionally well-known epoxy compound can be used as an epoxy compound. As for the said epoxy compound, only 1 type may be used and 2 or more types may be used together.

  Examples of the epoxy compound include phenoxy resin having an epoxy group, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, biphenol type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, phenol aralkyl type epoxy. Examples thereof include a resin, a naphthol aralkyl type epoxy resin, a dicyclopentadiene type epoxy resin, an anthracene type epoxy resin, an epoxy resin having an adamantane skeleton, an epoxy resin having a tricyclodecane skeleton, and an epoxy resin having a triazine nucleus in the skeleton.

  Specific examples of the epoxy compound include, for example, epichlorohydrin and bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol D type epoxy resin and the like, bisphenol type epoxy resin, and epichlorohydrin and phenol novolac or cresol novolak. And epoxy novolac resins derived from Various epoxy compounds having two or more oxirane groups in one molecule such as glycidylamine, glycidyl ester, and alicyclic or heterocyclic may be used.

  Furthermore, as the epoxy compound, for example, a structure in which the thiirane group in the structure represented by the formula (1-1), (2-1), (3), (7) or (8) is replaced with an epoxy group is used. You may use the epoxy compound which has.

  Further, the anisotropic conductive material may be an epoxy compound monomer having a structure represented by the following formula (21), a multimer in which at least two of the epoxy compounds are bonded, or the monomer as an epoxy compound. It may contain a mixture of the body and the multimer.

  In said formula (21), R1 represents a C1-C5 alkylene group, R2 represents a C1-C5 alkylene group, R3 is a hydrogen atom, a C1-C5 alkyl group, or following formula ( 22), R4 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a structure represented by the following formula (23).

  In said formula (22), R5 represents a C1-C5 alkylene group.

  In said formula (23), R6 represents a C1-C5 alkylene group.

  The epoxy compound having the structure represented by the above formula (21) has an unsaturated double bond and at least two epoxy groups. By using the epoxy compound having the structure represented by the above formula (21), the anisotropic conductive material can be rapidly cured at a lower temperature.

  The anisotropic conductive material is, as an epoxy compound or an episulfide compound, a monomer of a compound having a structure represented by the following formula (31), a multimer in which at least two of the compounds are bonded, or the monomer And a mixture of the multimers.

  In the above formula (31), R1 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a structure represented by the following formula (32), R2 represents an alkylene group having 1 to 5 carbon atoms, and R3 represents carbon. X 1 represents an oxygen atom or a sulfur atom, and X 2 represents an oxygen atom or a sulfur atom.

  In said formula (32), R4 represents a C1-C5 alkylene group, X3 represents an oxygen atom or a sulfur atom.

  The anisotropic conductive material may contain an epoxy compound having a heterocyclic ring containing a nitrogen atom as an epoxy compound. The epoxy compound having a heterocyclic ring containing a nitrogen atom is preferably an epoxy compound represented by the following formula (41) or an epoxy compound represented by the following formula (42). By using such a compound, the curing rate of the anisotropic conductive material can be further increased, and the heat resistance of the cured product can be further enhanced.

  In said formula (41), R1-R3 represents a C1-C5 alkylene group, respectively, Z represents an epoxy group or a hydroxymethyl group. R1 to R3 may be the same or different.

  In the above formula (42), R1 to R3 each represent an alkylene group having 1 to 5 carbon atoms, p, q and r each represents an integer of 1 to 5, and R4 to R6 each represent an alkylene having 1 to 5 carbon atoms. Represents a group. R1 to R3 may be the same or different. p, q and r may be the same or different. R4-6 may be the same or different.

  The epoxy compound having a heterocyclic ring containing a nitrogen atom is preferably triglycidyl isocyanurate or trishydroxyethyl isocyanurate triglycidyl ether. By using these compounds, the curing rate of the anisotropic conductive material can be further increased.

  The anisotropic conductive material preferably contains an epoxy compound having an aromatic ring as an epoxy compound. By using an epoxy compound having an aromatic ring, the curing rate of the anisotropic conductive material can be further increased and the anisotropic conductive paste can be easily applied. From the viewpoint of further improving the applicability of the anisotropic conductive paste, the aromatic ring is preferably a benzene ring, a naphthalene ring or an anthracene ring. Examples of the epoxy compound having an aromatic ring include resorcinol diglycidyl ether or 1,6-naphthalenediglycidyl ether. Of these, resorcinol diglycidyl ether is particularly preferable. By using resorcinol diglycidyl ether, the curing rate of the anisotropic conductive material can be increased and the paste-like anisotropic conductive paste can be easily applied.

[Photocurable compound]
The anisotropic conductive material according to the present invention may contain a photocurable compound so as to be cured by light irradiation. By photoirradiation, the photocurable compound can be semi-cured to reduce the fluidity of the curable compound.

  It does not specifically limit as said photocurable compound, (meth) acrylic resin, cyclic ether group containing resin, etc. are mentioned.

  The photocurable compound is preferably a photocurable compound having a (meth) acryloyl group. The photocurable compound having the (meth) acryloyl group has no epoxy group and thiirane group, and has a (meth) acryloyl group, and has an epoxy group or thiirane group, and ( The photocurable compound which has a (meth) acryloyl group is mentioned.

  The photocurable compound having the (meth) acryloyl group is obtained by reacting (meth) acrylic acid with a compound having a hydroxyl group, and reacting (meth) acrylic acid with an epoxy compound. Epoxy (meth) acrylate or urethane (meth) acrylate obtained by reacting an isocyanate with a (meth) acrylic acid derivative having a hydroxyl group is preferably used. The “(meth) acryloyl group” refers to an acryloyl group and a methacryloyl group. The “(meth) acryl” refers to acryl and methacryl. The “(meth) acrylate” refers to acrylate and methacrylate.

  The ester compound obtained by making the said (meth) acrylic acid and the compound which has a hydroxyl group react is not specifically limited. As the ester compound, any of a monofunctional ester compound, a bifunctional ester compound, and a trifunctional or higher functional ester compound can be used.

  The photocurable compound having the epoxy group or thiirane group and having a (meth) acryloyl group is a part of the epoxy group or part of thiirane of the compound having two or more epoxy groups or two or more thiirane groups. It is preferable that it is a photocurable compound obtained by converting a group into a (meth) acryloyl group. Such a photocurable compound is a partially (meth) acrylated epoxy compound or a partially (meth) acrylated episulfide compound.

  The photocurable compound is preferably a reaction product of a compound having two or more epoxy groups or two or more thiirane groups and (meth) acrylic acid. This reaction product is obtained by reacting a compound having two or more epoxy groups or two or more thiirane groups with (meth) acrylic acid in the presence of a basic catalyst according to a conventional method. It is preferable that 20% or more of the epoxy group or thiirane group is converted (converted) to a (meth) acryloyl group. The conversion is more preferably 30% or more, preferably 80% or less, more preferably 70% or less. Most preferably, 40% or more and 60% or less of the epoxy group or thiirane group is converted to a (meth) acryloyl group.

  Examples of the partially (meth) acrylated epoxy compound include bisphenol type epoxy (meth) acrylate, cresol novolac type epoxy (meth) acrylate, carboxylic acid anhydride-modified epoxy (meth) acrylate, and phenol novolac type epoxy (meth) acrylate. Is mentioned.

  Even if it uses the modified phenoxy resin which converted some epoxy groups or some thiirane groups of the phenoxy resin which has two or more epoxy groups or two or more thiirane groups into a (meth) acryloyl group as a photocurable compound. Good. That is, a modified phenoxy resin having an epoxy group or thiirane group and a (meth) acryloyl group may be used.

  Further, the photocurable compound may be a crosslinkable compound or a non-crosslinkable compound.

  Specific examples of the crosslinkable compound include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, (poly ) Ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, glycerol methacrylate acrylate, pentaerythritol tri (meth) acrylate, tri Examples include methylolpropane trimethacrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, polyester (meth) acrylate, and urethane (meth) acrylate.

  Specific examples of the non-crosslinkable compound include ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) ) Acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl (Meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, and the like.

  When a photocurable compound and a thermosetting compound are used in combination, the blending ratio of the photocurable compound and the thermosetting compound is appropriately adjusted according to the type of the photocurable compound and the thermosetting compound. The When the photocurable compound and the thermosetting compound are used in combination, the anisotropic conductive material according to the present invention has a weight ratio of the photocurable compound and the thermosetting compound of 1:99 to 90:10. Preferably, it is included at 5:95 to 60:40, more preferably 10:90 to 40:60.

(Thermosetting agent)
The said thermosetting agent is not specifically limited. A conventionally known thermosetting agent can be used as the thermosetting agent. Examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents, acid anhydrides, and cationic curing agents. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  Since the anisotropic conductive material can be cured more rapidly at a low temperature, the thermosetting agent is preferably an imidazole curing agent, a polythiol curing agent, or an amine curing agent. In addition, a latent curing agent is preferable because the storage stability of the anisotropic conductive material can be improved. The latent curing agent is preferably a latent imidazole curing agent, a latent polythiol curing agent or a latent amine curing agent. The thermosetting agent may be coated with a polymer material such as polyurethane resin or polyester resin.

  When the conductive surface of the conductive particles is a low melting point metal layer, it is preferable to use a cationic curing agent. With the acid generated from the cationic curing agent during curing, the oxide film present on the surface of the low melting point metal layer can be removed, the electrodes can be connected, and high reliability can be obtained.

  The imidazole curing agent is not particularly limited, and 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s- Examples include triazine isocyanuric acid adducts.

  The polythiol curing agent is not particularly limited, and examples thereof include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate. .

  The amine curing agent is not particularly limited, and hexamethylene diamine, octamethylene diamine, decamethylene diamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5]. Examples include undecane, bis (4-aminocyclohexyl) methane, metaphenylenediamine, and diaminodiphenylsulfone.

  As the cationic curing agent, an iodonium salt or a sulfonium salt is preferably used. Examples of the cationic curing agent include San-Aid SI-45L, SI-60L, SI-80L, SI-100L, SI-110L, and SI-150L manufactured by Sanshin Chemical Industry Co., Ltd., and ADEKA SP-150 and SP-170 etc. are mentioned.

Preferred anionic portions of the cationic curing agent include PF ₆ , BF ₄ , and B (C ₆ F ₅ ) ₄ .

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, with respect to 100 parts by weight of the total of the curable compound, preferably 100 parts by weight of the thermosetting compound. , Preferably 30 parts by weight or less, more preferably 20 parts by weight or less. When the content of the thermosetting agent is not less than the above lower limit and not more than the above upper limit, the anisotropic conductive material can be sufficiently thermoset.

(Photocuring initiator)
The photocuring initiator (photopolymerization initiator) is not particularly limited. A conventionally known photocuring initiator can be used as the photocuring initiator. As for the said photocuring initiator, only 1 type may be used and 2 or more types may be used together.

  The photocuring initiator is not particularly limited, and examples thereof include acetophenone photocuring initiator, benzophenone photocuring initiator, thioxanthone, ketal photocuring initiator, halogenated ketone, acyl phosphinoxide, and acyl phosphonate. .

  Specific examples of the acetophenone photocuring initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, methoxy Examples include acetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 2-hydroxy-2-cyclohexylacetophenone. Specific examples of the ketal photocuring initiator include benzyldimethyl ketal.

  The content of the photocuring initiator is not particularly limited. The content of the photocuring initiator is preferably 0.1 parts by weight or more, more preferably 0, with respect to 100 parts by weight of the total of the curable compound, preferably with respect to 100 parts by weight of the photocurable compound. .2 parts by weight or more, preferably 2 parts by weight or less, more preferably 1 part by weight or less. When the content of the photocuring initiator is not less than the above lower limit and not more than the above upper limit, the anisotropic conductive material can be appropriately photocured. By irradiating the anisotropic conductive material with light to form a B stage, the flow of the anisotropic conductive material can be suppressed. Moreover, the flow of the anisotropic conductive material can be suppressed by irradiating the anisotropic conductive material with light and semi-curing the light.

(Filler)
The anisotropic conductive material according to the present invention includes a filler (X) having a particle size of 10 nm or more and 1000 nm or less. The content of the filler (A) having a particle diameter of 10 nm or more and less than 300 nm is 10% by weight or more and 65% by weight or less in 100% by weight of the whole filler (X) having a particle diameter of 10 nm or more and 1000 nm or less. And the content of the filler (B) having a particle diameter of 300 nm or more and 1000 nm or less is 35 wt% or more and 90 wt% or less. By using the filler (X) satisfying such a content relationship, the conduction reliability in the connection structure can be increased. The content of the filler (A) having a particle diameter of 10 nm or more and less than 300 nm in the total 100% by weight of the filler (X) is preferably 11% by weight or more, and preferably 64% by weight or less.

  The filler (A) enhances crack resistance by a stress relaxation action. Accordingly, the use of the filler (A) improves the crack resistance, so that the conduction reliability in the connection structure can be further improved.

  From the viewpoint of further improving the conduction reliability in the connection structure, the filler having a particle diameter of 300 nm or more and less than 600 nm in 100% by weight of the whole filler (X) having a particle diameter of 10 nm or more and 1000 nm or less (B1 ) Is preferably 0% by weight or more and 10% by weight or less. The filler (B1) may not be included and may be included. Even if the filler (B1) is included, the conduction reliability in the connection structure can be increased.

  The content of the filler (B2) having a particle diameter of 600 nm or more and 1000 nm or less is preferably 30% by weight or more in 100% by weight of the whole filler (X) having a particle diameter of 10 nm or more and 1000 nm or less. Such a filler (B2) has high electrical insulation, and short circuit defects can be suppressed by using the filler (B2), so that the conduction reliability in the connection structure can be further improved. From the viewpoint of making the electrical insulation even better, the content of the filler (B2) in the total 100% by weight of the filler (X) is more preferably 35% by weight or more, preferably 90% by weight or less, more Preferably it is 80 weight% or less. From the viewpoint of further improving the crack resistance and further improving the conduction reliability in the connection structure, the filler (A) having a particle diameter of 10 nm or more and less than 300 nm preferably contains core-shell particles. The core-shell particles have a core layer and a shell layer that covers the surface of the core layer. From the viewpoint of further suppressing the core-shell particles from being sandwiched between the conductive particles and the electrode, the core layer is preferably formed of a silicone resin, and the shell layer is formed of a (meth) acrylic resin. Preferably it is formed. From the viewpoint of further suppressing the core-shell particle from being sandwiched between the conductive particle and the electrode, the core-shell particle is a shell layer in which a core layer formed of a silicone resin is formed of a (meth) acrylic resin. It is preferably coated.

  Furthermore, the filler (A) having a particle diameter of 10 nm or more and less than 300 nm preferably contains inorganic particles from the viewpoint of further improving the applicability and further improving the conduction reliability in the connection structure. Examples of the material of the inorganic particles include alumina, synthetic magnesite, silica, boron nitride, aluminum nitride, silicon nitride, silicon carbide, zinc oxide, magnesium oxide, talc, mica and hydrotalcite. Among these, silica is preferable because the coating property is further improved.

  The filler (B2) having a particle size of 600 nm or more and 1000 nm or less is preferably a hydrophobized filler. The surface of the filler is hydrophobized by surface treatment with a silane coupling agent having a hydrophobic group. When the filler is hydrophobized, the compatibility with the binder resin is improved, particularly the compatibility with the epoxy resin as the binder resin is improved, and the dispersibility is further improved. Examples of the compound used for the hydrophobization treatment include vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxylane, γ-glyridoxypropyl-trimethoxysilane, and vinyltrimethoxysilane.

  In the present specification, the “particle diameter” of the filler is a particle diameter obtained from a volume average particle diameter obtained from a volume distribution measured by a laser diffraction particle size distribution measuring apparatus.

The total content of the filler (X) having a particle diameter of 10 nm or more and 1000 nm or less with respect to 100 parts by weight of the curable compound is preferably 15 parts by weight or more, more preferably 30 parts by weight or more, preferably 75 parts by weight or less, more preferably 65 parts by weight or less. When the filler content is not less than the above lower limit and not more than the above upper limit, the conduction reliability in the obtained connection structure can be further enhanced.

  The added weight part of the filler with respect to 100 parts by weight of the curable compound can be calculated from the specific gravity of the curable compound and the specific gravity of the filler.

(Conductive particles)
The conductive particles contained in the anisotropic conductive material electrically connect the electrodes of the first and second connection target members. The conductive particles are not particularly limited as long as they are conductive particles. The surface of the conductive layer of the conductive particles may be covered with an insulating layer. In this case, the insulating layer between the conductive layer and the electrode is excluded when the connection target member is connected. Examples of the conductive particles include conductive particles whose surfaces are covered with a metal layer, such as organic particles, inorganic particles, organic-inorganic hybrid particles, or metal particles, or metal particles that are substantially composed only of metal. It is done. The metal layer is not particularly limited. Examples of the metal layer include a gold layer, a silver layer, a copper layer, a nickel layer, a palladium layer, or a metal layer containing tin.

  From the viewpoint of increasing the contact area between the electrode and the conductive particle and further improving the conduction reliability between the electrodes, the conductive particle includes a resin particle and a conductive layer disposed on the surface of the resin particle. It is preferable to have. From the viewpoint of further improving the conduction reliability between the electrodes, the conductive particles are preferably conductive particles having at least an outer conductive surface as a low melting point metal layer. More preferably, the conductive particles include resin particles and a conductive layer disposed on the surface of the resin particles, and at least the outer surface of the conductive layer is a low melting point metal layer.

  The low melting point metal layer is a layer containing a low melting point metal. The low melting point metal is a metal having a melting point of 450 ° C. or lower. The melting point of the low melting point metal is preferably 300 ° C. or lower, more preferably 160 ° C. or lower. The low melting point metal layer preferably contains tin. In 100% by weight of the metal contained in the low melting point metal layer, the content of tin is preferably 30% by weight or more, more preferably 40% by weight or more, still more preferably 70% by weight or more, and particularly preferably 90% by weight or more. . When the content of tin in the low melting point metal layer is not less than the above lower limit, the connection reliability between the low melting point metal layer and the electrode is further enhanced. The tin content is determined using a high frequency inductively coupled plasma optical emission spectrometer (“ICP-AES” manufactured by Horiba, Ltd.) or a fluorescent X-ray analyzer (“EDX-800HS” manufactured by Shimadzu). It can be measured.

  When the outer surface of the conductive layer is a low melting point metal layer, the low melting point metal layer is melted and joined to the electrodes, and the low melting point metal layer conducts between the electrodes. For example, since the low-melting point metal layer and the electrode are not in point contact but in surface contact, the connection resistance is lowered. In addition, the use of conductive particles having at least the outer surface of a low-melting-point metal layer increases the bonding strength between the low-melting-point metal layer and the electrode. , The conduction reliability is effectively increased.

  The low melting point metal which comprises the said low melting metal layer is not specifically limited. The low melting point metal is preferably tin or an alloy containing tin. Examples of the alloy include a tin-silver alloy, a tin-copper alloy, a tin-silver-copper alloy, a tin-bismuth alloy, a tin-zinc alloy, and a tin-indium alloy. Especially, since it is excellent in the wettability with respect to an electrode, it is preferable that the said low melting metal is a tin, a tin-silver alloy, a tin-silver-copper alloy, a tin-bismuth alloy, and a tin-indium alloy. More preferred are a tin-bismuth alloy and a tin-indium alloy.

The low melting point metal layer is preferably a solder layer. Although the material which comprises the said solder layer is not specifically limited, Based on JISZ3001: solvent term, it is preferable that it is a meltable material whose liquidus is 450 degrees C or less. As a composition of the said solder layer, the metal composition containing zinc, gold | metal | money, lead, copper, tin, bismuth, indium etc. is mentioned, for example. Among them, a tin-indium system (117 ° C. eutectic) or a tin-bismuth system (139 ° C. eutectic) which is low-melting and lead-free is preferable. That is, the solder layer preferably does not contain lead, and is preferably a solder layer containing tin and indium or a solder layer containing tin and bismuth.

  In order to further increase the bonding strength between the low melting point metal layer and the electrode, the low melting point metal layer is made of nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, bismuth. Further, it may contain a metal such as manganese, chromium, molybdenum and palladium. From the viewpoint of further increasing the bonding strength between the low melting point metal and the electrode, the low melting point metal preferably contains nickel, copper, antimony, aluminum, or zinc. From the viewpoint of further increasing the bonding strength between the low melting point metal layer and the electrode, the content of these metals for increasing the bonding strength is 100 wt% of the low melting point metal layer, preferably 0.0001 wt% or more, Preferably it is 1 weight% or less.

  The conductive particles include resin particles and a conductive layer disposed on the surface of the resin particles, and the outer surface of the conductive layer is a low melting point metal layer (such as a solder layer). In addition to the low melting point metal layer, a second conductive layer is preferably provided between the low melting point metal layer and the low melting point metal layer. In this case, the low melting point metal layer is a part of the entire conductive layer, and the second conductive layer is a part of the entire conductive layer.

  The second conductive layer different from the low melting point metal layer preferably contains a metal. The metal constituting the second conductive layer is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and alloys thereof. Further, tin-doped indium oxide (ITO) may be used as the metal. As for the said metal, only 1 type may be used and 2 or more types may be used together.

  The second conductive layer is preferably a nickel layer, a palladium layer, a copper layer, or a gold layer, more preferably a nickel layer or a gold layer, and even more preferably a copper layer. The conductive particles preferably have a nickel layer, a palladium layer, a copper layer, or a gold layer, more preferably have a nickel layer or a gold layer, and still more preferably have a copper layer. By using the conductive particles having these preferable conductive layers for the connection between the electrodes, the connection resistance between the electrodes is further reduced. In addition, a low melting point metal layer can be more easily formed on the surface of these preferable conductive layers. The second conductive layer may be a low melting point metal layer such as a solder layer. The conductive particles may have a plurality of low melting point metal layers.

  The thickness of the low melting point metal layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, still more preferably 1 μm or more, preferably 50 μm or less, more preferably 10 μm or less, still more preferably 5 μm or less, particularly preferably. 3 μm or less. When the thickness of the low melting point metal layer is not less than the above lower limit, the conductivity is sufficiently high. When the thickness of the low melting point metal layer is not more than the above upper limit, the difference in thermal expansion coefficient between the resin particles and the low melting point metal layer becomes small, and the low melting point metal layer is hardly peeled off.

  When the conductive layer is a conductive layer other than the low melting point metal layer, or when the conductive layer has a multilayer structure, the total thickness of the conductive layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, Preferably it is 1 micrometer or more, Preferably it is 50 micrometers or less, More preferably, it is 10 micrometers or less, More preferably, it is 5 micrometers or less, Most preferably, it is 3 micrometers or less.

  The particle diameter of the conductive particles is preferably 100 μm or less, more preferably less than 20 μm, still more preferably 15 μm or less, and particularly preferably 10 μm or less. The particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more.

  Since the size is suitable for the conductive particles in the anisotropic conductive material and the distance between the electrodes can be further reduced, the average particle diameter of the conductive particles is in the range of 1 μm to 100 μm. Is particularly preferred.

  The resin particles can be properly used depending on the electrode size or land diameter of the substrate to be mounted.

  From the viewpoint of more reliably connecting the upper and lower electrodes and further suppressing the short circuit between the electrodes adjacent in the lateral direction, the ratio of the average particle diameter C of the conductive particles to the average particle diameter A of the resin particles ( C / A) is more than 1.0, preferably 3.0 or less. In addition, when the second conductive layer is present between the resin particles and the solder layer, the ratio of the resin particles to the average particle size B with respect to the average particle size B of the conductive particle portion excluding the solder layer (B / A) is greater than 1.0, preferably 2.0 or less. Further, when there is the second conductive layer between the resin particles and the solder layer, the average particle diameter B of the conductive particle portion excluding the solder layer having the average particle diameter C of the conductive particles including the solder layer. The ratio (C / B) to is more than 1.0, preferably 2.0 or less. When the ratio (B / A) is within the above range or the ratio (C / B) is within the above range, electrodes that are more reliably connected between the upper and lower electrodes and that are adjacent in the lateral direction The short circuit between them can be further suppressed.

Anisotropic conductive materials for FOB and FOF applications:
The anisotropic conductive material is used for connection between a flexible printed circuit board and a glass epoxy board (FOB (Film on Board)), or between a flexible printed circuit board and a flexible printed circuit board (FOF (Film on Film)). Preferably used.

  In FOB and FOF applications, L & S, which is the size of a portion (line) with an electrode and a portion (space) without an electrode, is generally 100 to 500 μm. The average particle diameter of the resin particles used for FOB and FOF applications is preferably 10 to 100 μm. When the average particle diameter of the resin particles is 10 μm or more, the thickness of the anisotropic conductive material disposed between the electrodes and the connection portion is sufficiently increased, and the adhesive force is further increased. When the average particle diameter of the resin particles is 100 μm or less, a short circuit is more unlikely to occur between adjacent electrodes.

Anisotropic conductive materials for flip chip applications:
The anisotropic conductive material is suitably used for flip chip applications.

  For flip chip applications, the land diameter is generally 15-80 μm. The average particle size of the resin particles used for flip chip applications is preferably 1 to 15 μm. When the average particle diameter of the resin particles is 1 μm or more, the thickness of the solder layer disposed on the surface of the resin particles can be sufficiently increased, and the electrodes can be more reliably electrically connected. it can. When the average particle diameter of the resin particles is 10 μm or less, a short circuit is more unlikely to occur between adjacent electrodes.

Anisotropic conductive material for COF:
The anisotropic conductive material is preferably used for connection between a semiconductor chip and a flexible printed board (COF (Chip on Film)).

In a COF application, L & S, which is a dimension between a portion (line) with an electrode and a portion (space) without an electrode (space), is generally 10 to 50 μm. The average particle diameter of the resin particles used for COF applications is preferably 1 to 10 μm. When the average particle diameter of the resin particles is 1 μm or more, the thickness of the solder layer disposed on the surface of the resin particles can be sufficiently increased, and the electrodes can be more reliably electrically connected. it can. When the average particle diameter of the resin particles is 10 μm or less, a short circuit is more unlikely to occur between adjacent electrodes.

  The “average particle size” of the conductive particles indicates a number average particle size. The average particle diameter of the conductive particles can be obtained by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating an average value.

  The surface of the conductive particles may be insulated with an insulating material, insulating particles, flux, or the like. It is preferable that the insulating material, the insulating particles, the flux, and the like are removed from the connection portion by being softened and flowed by heat at the time of connection. Thereby, the short circuit between electrodes can be suppressed.

  The content of the conductive particles is not particularly limited. The content of the conductive particles in 100% by weight of the anisotropic conductive material is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 40% by weight or less, more preferably 20% by weight. % Or less, more preferably 10% by weight or less. A conductive particle can be easily arrange | positioned between the upper and lower electrodes which should be connected as content of the said electroconductive particle is more than the said minimum and below the said upper limit. Furthermore, it becomes difficult to electrically connect adjacent electrodes that should not be connected via a plurality of conductive particles. That is, a short circuit between adjacent electrodes can be further prevented.

  When the conductive layer in the conductive particles has a low melting point metal layer, and the low melting point metal layer is located on the conductive surface outside the conductive particles, the oxide film formed on the outer surface of the low melting point metal layer The thickness of is preferably 10 nm or less. If it is 10 nm or less, the oxide film is destroyed by the pressure applied when the connection structure is connected, and good connection is possible. The thickness of the oxide film can be measured with a transmission electron microscope (TEM).

(Other ingredients)
The anisotropic conductive material preferably further contains a curing accelerator. By using a curing accelerator, the curing rate can be further increased. As for a hardening accelerator, only 1 type may be used and 2 or more types may be used together.

  Specific examples of the curing accelerator include imidazole curing accelerators and amine curing accelerators. Of these, imidazole curing accelerators are preferred. In addition, an imidazole hardening accelerator or an amine hardening accelerator can be used also as an imidazole hardening agent or an amine hardening agent.

  Examples of the imidazole curing accelerator include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino- 6- [2′-Methylimidazolyl- (1 ′)]-ethyl-s-triazine and 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine isocyanuric acid addition Thing etc. are mentioned.

  The content of the curing accelerator is preferably 0.5 parts by weight or more, more preferably 1 part by weight with respect to 100 parts by weight of the total of the curable compound, preferably 100 parts by weight of the thermosetting compound. Part or more, preferably 6 parts by weight or less, more preferably 4 parts by weight or less. When the content of the curing accelerator is not less than the above lower limit, it is easy to sufficiently cure the anisotropic conductive material. When the content of the curing accelerator is less than or equal to the above upper limit, it is difficult for an excessive curing accelerator that did not participate in curing after curing to remain.

It is preferable that the anisotropic conductive material further includes a phenolic compound together with the episulfide compound. The combined use of the episulfide compound, the thermosetting agent, and the phenolic compound makes it more difficult for the thiirane group to open during storage of the anisotropic conductive material. Moreover, when an anisotropic conductive material is arrange | positioned between electrodes and an electroconductive particle is compressed appropriately, an appropriate indentation can be formed in an electrode. Therefore, the connection resistance between the electrodes can be lowered.

  The phenolic compound has a phenolic hydroxyl group in which a hydroxyl group is bonded to a benzene ring. Examples of the phenolic compound include polyphenol, triol, hydroquinone, and tocopherol (vitamin E). As for the said phenolic compound, only 1 type may be used and 2 or more types may be used together.

  The anisotropic conductive material may contain a solvent. By using the solvent, the viscosity of the anisotropic conductive material can be easily adjusted. Examples of the solvent include ethyl acetate, methyl cellosolve, toluene, acetone, methyl ethyl ketone, cyclohexane, n-hexane, tetrahydrofuran, and diethyl ether.

  The anisotropic conductive material preferably contains a storage stabilizer. The anisotropic conductive material preferably contains at least one selected from the group consisting of phosphate ester, phosphite ester and borate ester as the storage stabilizer. It is more preferable that at least one of them is included, and it is even more preferable that a phosphite is included. By using these storage stabilizers, particularly by using phosphites, the storage stability of the episulfide compound can be further enhanced. As for the said storage stabilizer, only 1 type may be used and 2 or more types may be used together.

  The anisotropic conductive material includes at least one component selected from the group consisting of ascorbic acid, ascorbic acid derivatives, ascorbic acid salts, isoascorbic acid, isoascorbic acid derivatives, and isoascorbic acid salts. You may go out. By blending these components, the storage stability of the anisotropic conductive material is increased.

  The anisotropic conductive material may further contain an ion scavenger or a silane coupling agent as necessary.

  In addition, the anisotropic conductive material may contain a photocurable compound and a photopolymerization initiator so that the anisotropic conductive material can be cured by light irradiation. In the case of a two-step reaction in which the resin is semi-cured by light irradiation and then fully cured by heat, the anisotropic conductive material can shorten the reaction time during the main curing.

(Details and applications of anisotropic conductive materials)
The anisotropic conductive material according to the present invention is a paste-like or film-like anisotropic conductive material, and is preferably a paste-like anisotropic conductive material. The paste-like anisotropic conductive material is an anisotropic conductive paste. The film-like anisotropic conductive material is an anisotropic conductive film. When the anisotropic conductive material is an anisotropic conductive film, a film that does not include conductive particles may be laminated on the anisotropic conductive film that includes the conductive particles.

  The viscosity of the anisotropic conductive paste at 25 ° C. is preferably 20 Pa · s or more, and preferably 300 Pa · s or less. When the viscosity is equal to or higher than the lower limit, sedimentation of conductive particles in the anisotropic conductive paste can be suppressed. When the viscosity is equal to or lower than the upper limit, the dispersibility of the conductive particles is further increased. If the viscosity of the anisotropic conductive paste before coating is within the above range, after applying the anisotropic conductive paste on the first connection target member, the flow of the anisotropic conductive paste before curing is further increased. It can be further suppressed.

  The anisotropic conductive material which concerns on this invention can be used in order to adhere | attach various connection object members. The anisotropic conductive material is suitably used for obtaining a connection structure in which the first and second connection target members are electrically connected.

  FIG. 1 is a cross-sectional view schematically showing an example of a connection structure using an anisotropic conductive material according to an embodiment of the present invention.

  A connection structure 1 shown in FIG. 1 includes a first connection target member 2, a second connection target member 4, and a connection part 3 connecting the first and second connection target members 2 and 4. Prepare. The connection portion 3 is a cured product layer and is formed by curing an anisotropic conductive material including the conductive particles 5.

  A plurality of electrodes 2 b are provided on the upper surface 2 a (front surface) of the first connection target member 2. A plurality of electrodes 4 b are provided on the lower surface 4 a (front surface) of the second connection target member 4. The electrode 2b and the electrode 4b are electrically connected by one or a plurality of conductive particles 5. Therefore, the first and second connection target members 2 and 4 are electrically connected by the conductive particles 5. In FIG. 1, since the filler (X) is small, the filler (X) is not shown.

  The connection between the electrodes 2b and 4b is usually performed after the first connection target member 2 and the second connection target member 4 are overlapped with each other via the anisotropic conductive material so that the electrodes 2b and 4b face each other. When the anisotropic conductive material is cured, it is performed by applying pressure. Generally, the conductive particles 5 are compressed by pressurization. Use of the anisotropic conductive material according to the present invention makes it difficult for the filler to be sandwiched between the conductive particles 5 and the electrodes 2b and 4b. For this reason, the connection reliability of the connection structure 1 obtained can be improved.

  Specifically, as the connection structure, an electronic component chip such as a semiconductor chip, a capacitor chip or a diode chip is mounted on a circuit board, and the electrode of the electronic component chip is connected to an electrode on the circuit board. Examples include electrically connected structures. As a circuit board, various printed circuit boards, such as various printed circuit boards, such as a flexible printed circuit board, a glass substrate, or a board | substrate with which metal foil was laminated | stacked are mentioned. The first and second connection target members are preferably electronic components or circuit boards.

  The connection structure 1 shown in FIG. 1 can be obtained, for example, through the state shown in FIGS. 2A and 2B as follows.

  As shown to Fig.2 (a), the 1st connection object member 2 which has the electrode 2b on the upper surface 2a is prepared. Next, an anisotropic conductive material including a plurality of conductive particles 5 is disposed on the upper surface 2a of the first connection target member 2, and the anisotropic conductive material layer 3A is disposed on the upper surface 2a of the first connection target member 2. Form. At this time, it is preferable that one or a plurality of conductive particles 5 be disposed on the electrode 2b.

  Next, the anisotropic conductive material layer 3A is cured by irradiating light or applying heat to the anisotropic conductive material layer 3A. In FIG. 2, the anisotropic conductive material layer 3 </ b> A is irradiated with light to advance the curing of the anisotropic conductive material layer 3 </ b> A, so that the anisotropic conductive material layer 3 </ b> A is B-staged. That is, as shown in FIG. 2 (b), a B-stage-shaped cured product layer 3 </ b> B that is B-staged is formed on the upper surface 2 a of the first connection target member 2. The first connection object member 2 and the B-stage-shaped cured product layer 3B are temporarily bonded by the B-stage. The B-stage-shaped cured product layer 3B is a semi-cured product in a semi-cured state. The B-stage-shaped cured product layer 3B is not completely cured, and thermal curing can further proceed. However, the anisotropic conductive material layer 3A is not irradiated with light, that is, the anisotropic conductive material layer 3A is not B-staged, and heat is applied to the anisotropic conductive material layer 3A. The material layer 3A may be cured at a time.

In order to appropriately cure the anisotropic conductive material layer 3A, it is preferable that the irradiation energy of light in the irradiation with light is in the range of 50 to 200 mJ / cm ² . The light source used when irradiating light is not specifically limited. Examples of the light source include a light source having a sufficient light emission distribution at a wavelength of 420 nm or less. Specific examples of the light source include, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excitation mercury lamp, and a metal halide lamp.

  Next, as shown in FIG.2 (c), the 2nd connection object member 4 is laminated | stacked on the upper surface 3a of B stage-shaped hardened | cured material layer 3B. The second connection target member 4 is laminated so that the electrode 2b on the upper surface 2a of the first connection target member 2 and the electrode 4b on the lower surface 4a of the second connection target member 4 face each other.

  Further, when the second connection target member 4 is laminated, by applying heat to the B-stage-shaped cured product layer 3B (heating), the B-stage cured product layer 3B is further cured to form a cured product layer. A connecting portion 3 is formed. However, before the second connection target member 4 is laminated, heat may be applied to the B-stage-shaped cured product layer 3B. Further, heat may be applied to the B-stage-shaped cured product layer 3B after the second connection target member 4 is laminated.

  The heating temperature for curing the anisotropic conductive material layer 3A or the B-stage cured product layer 3B by application of heat is preferably 160 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower.

  It is preferable to apply pressure when the B-stage-shaped cured product layer 3B is cured. By compressing the conductive particles 5 with the electrodes 2b and 4b by pressurization, the contact area between the electrodes 2b and 4b and the conductive particles 5 can be increased. For this reason, conduction reliability can be improved.

  By curing the B-stage-shaped cured product layer 3 </ b> B, the first connection target member 2 and the second connection target member 4 are connected via the connection portion 3. Further, the electrode 2 b and the electrode 4 b are electrically connected through the conductive particles 5. In this way, the connection structure 1 shown in FIG. 1 using the anisotropic conductive paste can be obtained. Here, since photocuring and thermosetting are used together, the anisotropic conductive paste can be cured in a short time.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

Example 1
(1) Preparation of anisotropic conductive paste An episulfide compound having a structure represented by the following formula (1B) was prepared.

Further, as filler (X) having a particle diameter of 10 nm or more and 1000 nm or less, silica having an introduced methyl group (average particle diameter 700 nm, hydrophobized filler, manufactured by Tokuyama Corporation (prototype), specific gravity: 2. 2) 45 parts by weight and core-shell particles (average particle size 200 nm,
Core layer: silicone resin, shell layer: (meth) acrylic resin, “W-450” manufactured by Mitsubishi Rayon Co., specific gravity: 1) 10 parts by weight, silica (average particle size 100 nm, “NSS-4N” manufactured by Tokuyama Co., Ltd., Specific gravity: 2.2) 2 parts by weight were prepared. Inclusion of filler (A) having a particle diameter of 10 nm or more and less than 300 nm in 100% by weight of the total mixture A (filler (X) having a particle diameter of 10 nm or more and 1000 nm or less) obtained by mixing these three kinds of fillers The content of the filler (B1) having an amount of 22% by weight, a particle size of 300 nm or more and less than 600 nm is 8% by weight, and the content of the filler (B2) having a particle size of 600 nm or more and 1000 nm or less is 69% by weight. there were. In addition, the particle size of the filler (X) in Example 1 and the examples and comparative examples described later are all determined from the volume distribution measured by a laser diffraction particle size distribution measuring device (“LA-920” manufactured by Horiba, Ltd.). The volume average particle diameter was obtained.

  100 parts by weight of an episulfide compound having a structure represented by the above formula (1B), 5 parts by weight of an amine adduct (“PN-23J” manufactured by Ajinomoto Fine Techno Co.) as a thermosetting agent, and 2- 1 part by weight of ethyl-4-methylimidazole, 45 parts by weight of the hydrophobized filler, 10 parts by weight of the core-shell particles, and 2 parts by weight of the silica are blended, and further conductive particles having an average particle diameter of 3 μm. After adding A so that the content in 100% by weight of the blend was 10% by weight, the blend was obtained by stirring for 5 minutes at 2000 rpm using a planetary stirrer.

  1 g of the resulting blend was diluted with 20 g of ethyl acetate, and the particle size distribution was measured using a laser diffraction particle size distribution analyzer (“LA-920” manufactured by Horiba Ltd.). The particle size was 10 nm or more and 300 nm. The filler (A) content is less than 22% by weight, the particle size is 300 nm or more and less than 600 nm, the filler (B1) content is 8% by weight, and the particle size is 600 nm or more and 1000 nm or less filler (B2 ) Content was 69% by weight, and there was no aggregation of particles. The parts by weight were calculated from the volume particle size distribution and specific gravity.

  The conductive particles A used are conductive particles having a metal layer in which a nickel plating layer is formed on the surface of divinylbenzene resin particles and a gold plating layer is formed on the surface of the nickel plating layer. It is.

  The obtained blend was filtered using a nylon filter paper (pore diameter: 10 μm) to obtain an anisotropic conductive paste having a conductive particle content of 10% by weight.

(2) Production of Connection Structure A transparent glass substrate having an ITO electrode pattern with an L / S of 20 μm / 20 μm formed on the upper surface was prepared. Further, a semiconductor chip having a copper electrode pattern with an L / S of 20 μm / 20 μm formed on the lower surface was prepared.

  On the said transparent glass substrate, the anisotropic electrically conductive paste which is the obtained curable composition was apply | coated so that it might become thickness 20 micrometers, and the anisotropic electrically conductive paste layer was formed. Next, the semiconductor chip was stacked on the anisotropic conductive paste layer so that the electrodes face each other and are connected. Then, while adjusting the temperature of the heating head so that the temperature of the anisotropic conductive paste layer is 185 ° C., the heating head is placed on the upper surface of the semiconductor chip and cured by applying a pressure of 3 MPa to obtain a connection structure. It was. In the connection structure obtained in Example 1, the deformation amount of the particle diameter of the conductive particles was 1000 nm.

(Example 2)
An episulfide compound having a structure represented by the following formula (2B) was prepared.

  An anisotropic conductive paste and a connecting structure as in Example 1 except that the episulfide compound having the structure represented by the above formula (1B) was changed to the episulfide compound represented by the above formula (2B). Got.

(Example 3)
An anisotropic conductive paste and a connecting structure in the same manner as in Example 1 except that the episulfide compound having the structure represented by the above formula (1B) was changed to an episulfide compound ("YL7007" manufactured by Mitsubishi Chemical Corporation). Got.

Example 4
An anisotropic conductive paste in the same manner as in Example 1 except that the episulfide compound having the structure represented by the above formula (1B) was changed to resorcinol glycidyl ether ("EX-201" manufactured by Nagase ChemteX Corporation). And the connection structure was obtained.

(Example 5)
53 parts by weight of silica having a methyl group introduced as a filler having a particle size of 10 nm or more and 1000 nm or less (average particle size 700 nm, hydrophobized filler, manufactured by Tokuyama (prototype), specific gravity: 2.2) 6.4 parts by weight of core-shell particles (average particle size 200 nm core layer: silicone resin, shell layer: (meth) acrylic resin, “W-450”, specific gravity: 1 manufactured by Mitsubishi Rayon Co., Ltd.) and silica (average particle size) 100 nm, “NSS-4N” manufactured by Tokuyama Corporation, specific gravity: 2.2) 0.2 parts by weight were prepared. Inclusion of filler (A) having a particle diameter of 10 nm or more and less than 300 nm in 100% by weight of the total mixture B (filler (X) having a particle diameter of 10 nm or more and 1000 nm or less) obtained by mixing these three kinds of fillers The content of the filler (B1) having an amount of 11% by weight, a particle size of 300 nm or more and less than 600 nm is 9% by weight, and the content of the filler (B2) having a particle size of 600 nm or more and 1000 nm or less is 80% by weight. there were.

  100 parts by weight of an episulfide compound having a structure represented by the above formula (1B), 5 parts by weight of an amine adduct (“PN-23J” manufactured by Ajinomoto Fine Techno Co.) as a thermosetting agent, and 2- 1 part by weight of ethyl-4-methylimidazole, 53 parts by weight of the hydrophobized filler, 6.4 parts by weight of the core-shell particles, and 0.2 part by weight of the silica are blended, and the average particle diameter is 3 μm. The conductive particles were added so that the content in 100% by weight of the formulation was 10% by weight, and then stirred for 5 minutes at 2000 rpm using a planetary stirrer to obtain a formulation.

  A connection structure was obtained in the same manner as in Example 1 except that the anisotropic conductive paste as the obtained composition was used.

(Example 6)
11 parts by weight of silica having a methyl group introduced as a filler having a particle size of 10 nm or more and 1000 nm or less (average particle size 700 nm, hydrophobized filler, manufactured by Tokuyama (prototype), specific gravity: 2.2) And 15 parts by weight of core-shell particles (average particle size 200 nm, core layer: silicone resin, shell layer: (meth) acrylic resin, “W-450”, specific gravity: 1 by Mitsubishi Rayon Co., Ltd.) and silica (average particle size 100 nm, “NSS-4N” manufactured by Tokuyama Corporation, specific gravity: 2.2) and 4.2 parts by weight were prepared. Inclusion of filler (A) having a particle diameter of 10 nm or more and less than 300 nm in 100% by weight of the mixture C (filler (X) having a particle diameter of 10 nm or more and 1000 nm or less) obtained by mixing these three kinds of fillers The amount of the filler (B1) having an amount of 64% by weight, a particle size of 300 nm or more and less than 600 nm is 4% by weight, and the content of the filler (B2) having a particle size of 600 nm or more and 1000 nm or less is 32% by weight. there were.

  100 parts by weight of an episulfide compound having a structure represented by the above formula (1B), 5 parts by weight of an amine adduct (“PN-23J” manufactured by Ajinomoto Fine Techno Co.) as a thermosetting agent, and 2- 1 part by weight of ethyl-4-methylimidazole, 11 parts by weight of the hydrophobized filler, 15 parts by weight of the core-shell particles, and 4.2 parts by weight of silica are blended, and a conductive material having an average particle diameter of 3 μm. After adding the functional particles so that the content in 100% by weight of the blend was 10% by weight, the blend was obtained by stirring for 5 minutes at 2000 rpm using a planetary stirrer.

  A connection structure was obtained in the same manner as in Example 1 except that the anisotropic conductive paste as the obtained composition was used.

(Example 7)
Conductive particles A2 having an average particle diameter of 7 μm were prepared. The conductive particles A2 have a metal layer in which a nickel plating layer is formed on the surface of the divinylbenzene resin particles and a gold plating layer is formed on the surface of the nickel plating layer.

  An anisotropic conductive paste and a connection structure were obtained in the same manner as in Example 1 except that the conductive particles A having an average particle diameter of 3 μm were changed to the conductive particles A2 having an average particle diameter of 7 μm.

(Comparative Example 1)
As a filler having a particle size of 10 nm or more and 1000 nm or less, 74 parts by weight of silica into which a methyl group has been introduced (average particle size 700 nm, hydrophobized filler, manufactured by Tokuyama (prototype), specific gravity: 2.2) 6.4 parts by weight of core-shell particles (average particle size 200 nm core layer: silicone resin, shell layer: (meth) acrylic resin, “W-450”, specific gravity: 1 manufactured by Mitsubishi Rayon Co., Ltd.) and silica (average particle size) 100 nm, “NSS-4N” manufactured by Tokuyama Corporation, specific gravity: 2.2) 0.2 parts by weight were prepared. Inclusion of filler (A) having a particle diameter of 10 nm or more and less than 300 nm in 100% by weight of the total mixture D (filler (X) having a particle diameter of 10 nm or more and 1000 nm or less) obtained by mixing these three kinds of fillers The amount was 8% by weight, the content of filler (B1) having a particle size of 300 nm or more and less than 600 nm was 11% by weight, and the content of filler (B2) having a particle size of 600 nm or more and 1000 nm or less was 81% by weight. It was.

  100 parts by weight of an episulfide compound having a structure represented by the above formula (1B), 5 parts by weight of an amine adduct (“PN-23J” manufactured by Ajinomoto Fine Techno Co.) as a thermosetting agent, and 2- 1 part by weight of ethyl-4-methylimidazole, 74 parts by weight of the hydrophobized filler, 6.4 parts by weight of the core-shell particles, and 0.2 part by weight of silica are blended, and the average particle size is 3 μm. The conductive particles were added so that the content in 100% by weight of the formulation was 10% by weight, and then stirred for 5 minutes at 2000 rpm using a planetary stirrer to obtain a formulation.

  A connection structure was obtained in the same manner as in Example 1 except that the anisotropic conductive paste as the obtained composition was used.

(Comparative Example 2)
11 parts by weight of silica having a methyl group introduced as a filler having a particle size of 10 nm or more and 1000 nm or less (average particle size 700 nm, hydrophobized filler, manufactured by Tokuyama (prototype), specific gravity: 2.2) And 19 parts by weight of core-shell particles (average particle size 200 nm core layer: silicone resin, shell layer: (meth) acrylic resin, “W-450”, specific gravity: 1 by Mitsubishi Rayon Co., Ltd.) and silica (average particle size 100 nm, “NSS-4N” manufactured by Tokuyama Corporation, specific gravity: 2.2) and 6.4 parts by weight were prepared. Inclusion of filler (A) having a particle diameter of 10 nm or more and less than 300 nm in 100% by weight of the mixture E (filler (X) having a particle diameter of 10 nm or more and 1000 nm or less) obtained by mixing these three kinds of fillers The content of the filler (B1) having an amount of 71% by weight, a particle size of 300 nm or more and less than 600 nm is 3% by weight, and the content of the filler (B2) having a particle size of 600 nm or more and 1000 nm or less is 26% by weight. there were.

  100 parts by weight of an episulfide compound having a structure represented by the above formula (1B), 5 parts by weight of an amine adduct (“PN-23J” manufactured by Ajinomoto Fine Techno Co.) as a thermosetting agent, and 2- 1 part by weight of ethyl-4-methylimidazole, 11 parts by weight of the hydrophobized filler, 19 parts by weight of the core-shell particles, and 6.4 parts by weight of silica are blended, and the conductive material has an average particle diameter of 3 μm. After adding the functional particles so that the content in 100% by weight of the blend was 10% by weight, the blend was obtained by stirring for 5 minutes at 2000 rpm using a planetary stirrer.

  A connection structure was obtained in the same manner as in Example 1 except that the anisotropic conductive paste as the obtained composition was used.

(Evaluation of Examples 1-7 and Comparative Examples 1-2)
(1) Conduction reliability (conductivity test between upper and lower electrodes)
The connection resistance between the upper and lower electrodes of 100 connection structures in which cracks are not generated in the cured product layer after performing a thermal cycle test (500 cycles and 1000 cycles) in the evaluation of (2) described later is a four-terminal method. It was measured by. The average value of the two connection resistances was calculated. The case where the average value of the connection resistance was 5.0Ω or less was judged as “good”, and the case where the average value of the connection resistance exceeded 5Ω was judged as “bad”.

  The conduction reliability was evaluated according to the following evaluation criteria from the proportion of connection structures determined to be good among 100 connection structures.

[Judgment criteria for conduction reliability]
◯: In 100 connection structures, the ratio of connection structures determined to be good is 95% or more. ○: In 100 connection structures, the ratio of connection structures determined as good is 90% or more. Less than 95% ×: Ratio of connection structures determined to be good in 100 connection structures is less than 90%

(2) Thermal shock characteristics Process of 200 obtained connection structures held at −30 ° C. for 30 minutes, then heated to 80 ° C., held at 80 ° C. for 30 minutes, and then cooled to −30 ° C. A cold cycle test was carried out with 1 cycle. After 500 cycles and 1000 cycles, 100 connection structures were taken out respectively.

It was evaluated whether or not cracks occurred in the cured product layer with respect to 100 connection structures after 500 cycles of the thermal cycle test and 100 connection structures after 1000 cycles of the thermal cycle test.

[Criteria for thermal shock resistance]
◯: The number of cracks not occurring in the cured product layer is 95 or more ○: The number of cracks not occurring in the cured product layer is 85 or more and less than 95 ×: The number of cracks not occurring in the cured product layer Less than 85

(Example 8)
(1) Preparation of anisotropic conductive paste 5 parts by weight of epoxy acrylate (“EBECRYL 3702” manufactured by Daicel-Cytec), which is a photocurable compound, and acylphosphine oxide compound (manufactured by Ciba Japan), which is a photopolymerization initiator An anisotropic conductive paste was obtained in the same manner as in Example 1 except that 0.1 part by weight of “DAROCUR TPO”) was further blended.

(2) Production of Connection Structure A transparent glass substrate having an ITO electrode pattern with an L / S of 20 μm / 20 μm formed on the upper surface was prepared. Further, a semiconductor chip having a copper electrode pattern with an L / S of 20 μm / 20 μm formed on the lower surface was prepared.

  On the transparent glass substrate, the obtained anisotropic conductive paste was applied to a thickness of 20 μm to form an anisotropic conductive paste layer. Next, the anisotropic conductive paste layer was irradiated with ultraviolet rays using an ultraviolet irradiation lamp, and the anisotropic conductive paste layer was semi-cured by photopolymerization to form a B stage. Next, the semiconductor chip was stacked on the anisotropic conductive paste layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and cured by applying a pressure of 3 MPa, and the connection structure is formed. Obtained.

Example 9
An anisotropic conductive paste and a connection structure were obtained in the same manner as in Example 1 except that the epoxy acrylate was changed to urethane acrylate ("EBECRYL8804" manufactured by Daicel-Cytec).

  (Evaluation of Examples 8-9)

(2) Conduction reliability (conductivity test between upper and lower electrodes)
In the same manner as in Examples 1 to 7 and Comparative Examples 1 and 2, the conduction reliability of the connection structures of Examples 8 to 9 was evaluated.

(3) Thermal shock characteristics The thermal shock characteristics of the connection structures of Examples 8-9 were evaluated in the same manner as in Examples 1-7 and Comparative Examples 1-2.

(Examples 10 to 18)
Divinylbenzene resin particles having an average particle diameter of 10 μm (“Micropearl SP-210” manufactured by Sekisui Chemical Co., Ltd.) were subjected to electroless nickel plating to form a base nickel plating layer having a thickness of 0.1 μm on the surface of the resin particles. Next, the resin particles on which the base nickel plating layer was formed were subjected to electrolytic copper plating to form a 1 μm thick copper layer. Furthermore, electrolytic plating was performed using an electrolytic plating solution containing tin and bismuth to form a solder layer having a thickness of 3 μm. Thus, a 1 μm thick copper layer is formed on the surface of the resin particles, and a 3 μm thick solder layer (tin: bismuth = 43 wt%: 57 wt%) is formed on the surface of the copper layer. Conductive particles B were prepared.

  In Example 10, the conductive particles A were changed to the conductive particles B, the filter paper used for the filtration was changed to nylon filter paper (pore diameter 30 μm), and the anisotropic conductive paste had a thickness of 40 μm. The anisotropic conductive paste and the connection structure were obtained in the same manner as in Example 1 except that the anisotropic conductive paste layer was formed.

  In Example 11, the conductive particles A were changed to the conductive particles B, the filter paper used for the filtration was changed to nylon filter paper (pore diameter 30 μm), and the anisotropic conductive paste had a thickness of 40 μm. The anisotropic conductive paste and the connection structure were obtained in the same manner as in Example 2 except that the anisotropic conductive paste layer was formed.

  In Example 12, the conductive particles A were changed to the conductive particles B, the filter paper used for the filtration was changed to nylon filter paper (pore diameter 30 μm), and the anisotropic conductive paste had a thickness of 40 μm. The anisotropic conductive paste and the connection structure were obtained in the same manner as in Example 3 except that the anisotropic conductive paste layer was formed.

  In Example 13, the conductive particles A were changed to the conductive particles B, the filter paper used for the filtration was changed to nylon filter paper (pore diameter 30 μm), and the anisotropic conductive paste had a thickness of 40 μm. The anisotropic conductive paste and the connection structure were obtained in the same manner as in Example 4 except that the anisotropic conductive paste layer was formed.

  In Example 14, the conductive particles A were changed to the conductive particles B, the filter paper used for the filtration was changed to nylon filter paper (pore diameter 30 μm), and the anisotropic conductive paste had a thickness of 40 μm. The anisotropic conductive paste and the connection structure were obtained in the same manner as in Example 5 except that the anisotropic conductive paste layer was formed.

  In Example 15, the conductive particles A were changed to the conductive particles B, the filter paper used for the filtration was changed to nylon filter paper (pore diameter 30 μm), and the anisotropic conductive paste had a thickness of 40 μm. The anisotropic conductive paste and the connection structure were obtained in the same manner as in Example 6 except that the anisotropic conductive paste layer was formed.

  In Example 16, the conductive particles A were changed to the conductive particles B, the filter paper used for the filtration was changed to nylon filter paper (pore diameter 30 μm), and the anisotropic conductive paste had a thickness of 40 μm. The anisotropic conductive paste and the connection structure were obtained in the same manner as in Example 8, except that the anisotropic conductive paste layer was formed.

  In Example 17, the conductive particles A were changed to the conductive particles B, the filter paper used for the filtration was changed to nylon filter paper (pore diameter 30 μm), and the anisotropic conductive paste had a thickness of 40 μm. The anisotropic conductive paste and the connection structure were obtained in the same manner as in Example 9, except that the anisotropic conductive paste layer was formed.

  In Example 18, the conductive particles A were changed to the conductive particles B, the filter paper used for the filtration was changed to nylon filter paper (pore size 30 μm), and the curing agent was a cationic curing agent (manufactured by Sanshin Chemical Industry Co., Ltd.). “SI-80”), and the anisotropic conductive paste was applied to a thickness of 40 μm to form an anisotropic conductive paste layer. An anisotropic conductive paste and a connection structure were obtained.

  (Evaluation of Examples 10-18)

(1) Conduction reliability (conductivity test between upper and lower electrodes)
In the same manner as in Examples 1 to 7 and Comparative Examples 1 and 2, the conduction reliability of the connection structures of Examples 10 to 18 was evaluated.

(2) Thermal shock characteristics The thermal shock characteristics of the connection structures of Examples 10 to 18 were evaluated in the same manner as in Examples 1 to 7 and Comparative Examples 1 and 2.

  The results are shown in Table 1 below.

  In Examples 10 to 18, the conduction reliability evaluation results are all “◯◯”, but the conduction reliability evaluation results of Examples 10 to 14 and 16 to 18 are the conduction reliability evaluation examples of Example 15. It was better than the evaluation result. Furthermore, in Examples 10 to 18, the thermal shock resistance evaluation results are all “◯◯”, but the conduction reliability evaluation results of Examples 10 to 13 and 15 to 18 are the thermal shock resistance of Example 14. It was better than the evaluation result of characteristics.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... Upper surface 2b ... Electrode 3 ... Connection part 3a ... Upper surface 3A ... Anisotropic conductive material layer 3B ... B stage-shaped hardened | cured material layer 4 ... 2nd connection object member 4a ... lower surface 4b ... electrode 5 ... conductive particles

Claims (10)

A curable compound curable by irradiation of light or application of heat, at least one of a photopolymerization initiator and a thermosetting agent, conductive particles, and a filler having a particle diameter of 10 nm or more and 1000 nm or less. Including
The content of the filler having a particle diameter of 10 nm or more and less than 300 nm is 10% by weight or more and 65% by weight or less in 100% by weight of the whole filler having a particle diameter of 10 nm or more and 1000 nm or less, and the particle diameter is An anisotropic conductive material in which the content of a filler that is 300 nm or more and 1000 nm or less is 35% by weight or more and 90% by weight or less.   The anisotropic conductive material of Claim 1 whose average particle diameter of the said electroconductive particle is 1 micrometer or more and 100 micrometers or less.   3. The difference according to claim 1, wherein the content of the filler having a particle diameter of 300 nm or more and less than 600 nm is 10% by weight or less in 100% by weight of the whole filler having a particle diameter of 10 nm or more and 1000 nm or less. Isotropic conductive material.   The content of the filler having a particle diameter of 600 nm or more and 1000 nm or less is 30% by weight or more in 100% by weight of the whole filler having a particle diameter of 10 nm or more and 1000 nm or less. The anisotropic conductive material according to item.   The anisotropic conductive material according to any one of claims 1 to 4, wherein the filler having a particle diameter of 10 nm or more and less than 300 nm includes core-shell particles.   The anisotropic conductive material according to any one of claims 1 to 4, wherein the filler having a particle diameter of 10 nm or more and less than 300 nm contains inorganic particles.   The anisotropic conductive material according to any one of claims 1 to 4, wherein the filler having a particle diameter of 10 nm or more and less than 300 nm includes both core-shell particles and inorganic particles.   The anisotropic conductive material according to claim 1, wherein the filler having a particle size of 600 nm or more and 1000 nm or less is a hydrophobized filler.   The total content of the filler having a particle size of 10 nm or more and 1000 nm or less with respect to 100 parts by weight of the curable compound is 15 parts by weight or more and 75 parts by weight or less. The anisotropic conductive material according to Item 1. A first connection target member, a second connection target member, and a connection portion that electrically connects the first and second connection target members;
The connection structure in which the said connection part is formed by hardening the anisotropic electrically-conductive material of any one of Claims 1-9.

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