JP5192950B2 - Curable epoxy composition, anisotropic conductive material, laminate, connection structure, and method for manufacturing connection structure - Google Patents

Description

  In the present invention, when stored in a semi-cured state that is not completely cured, curing does not easily proceed, and even when used for connection of a connection target member after being stored in a semi-cured state, The present invention relates to a curable epoxy composition that can be easily connected, an anisotropic conductive material using the curable epoxy composition, a laminate, a connection structure, and a method for manufacturing the connection structure.

  Anisotropic conductive materials such as anisotropic conductive pastes, anisotropic conductive inks, anisotropic conductive adhesives, anisotropic conductive films, and anisotropic conductive sheets are widely known.

  Anisotropic conductive materials are used for connection between an IC chip and a flexible printed circuit board, connection between an IC chip and a circuit board having an ITO electrode, and the like. 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, Patent Document 1 below includes a thermosetting adhesive, conductive particles, a latent curing agent having an imidazole structure, and a latent curing agent having an amine structure. An anisotropic conductive adhesive film is disclosed. Patent Document 1 describes that even when the anisotropic conductive adhesive film is cured at a relatively low temperature, the connection reliability is excellent.
JP-A-9-115335

  The anisotropic conductive adhesive film described in Patent Document 1 is formed on a protective film. When an IC chip is mounted on a circuit board using the anisotropic conductive adhesive film formed on the protective film, the anisotropic conductive adhesive film is peeled off from the protective film. An anisotropic conductive adhesive film is disposed between the IC chip and the circuit board, and the IC chip and the circuit board are thermocompression bonded.

  Therefore, the process of peeling an anisotropic conductive adhesive film from a protective film was required. Furthermore, the process of arrange | positioning an anisotropic conductive adhesive film between an IC chip and a circuit board was required. Since the protective film is peeled from the anisotropic conductive adhesive film, there is a problem that a large amount of the protective film is discarded. Further, since the anisotropic conductive adhesive film is disposed between the IC chip and the circuit board, there is a problem that the manufacturing process becomes complicated. Furthermore, it may be difficult to accurately position the anisotropic conductive adhesive film between the IC chip and the circuit board. Therefore, it has been strongly desired to omit such a process.

  In order to omit the above steps, it has been studied to previously form an anisotropic conductive adhesive layer on a circuit board. However, when an anisotropic conductive adhesive layer is formed on the circuit board by the anisotropic conductive adhesive film described in Patent Document 1, it is difficult to handle because the anisotropic conductive adhesive layer has high adhesiveness. There was a problem.

  Furthermore, in order to reduce the tackiness of the anisotropic conductive adhesive layer, when the anisotropic conductive adhesive layer is cured, the anisotropic conductive adhesive layer is not completely cured. It was difficult to control the curing reaction of the isotropic conductive adhesive layer. Further, when the anisotropic conductive adhesive layer in a semi-cured state is stored, the curing further proceeds and the stickiness of the anisotropic conductive adhesive layer may be lowered. For this reason, the IC chip and the circuit board may not be reliably connected.

  The object of the present invention is that the curing is difficult to proceed when stored in a semi-cured state that is not completely cured, and even if it is used for connection of a connection target member after being stored in a semi-cured state, An object of the present invention is to provide a curable epoxy composition capable of easily connecting members, an anisotropic conductive material using the curable epoxy composition, a laminate, a connection structure, and a method for manufacturing the connection structure.

  According to the present invention, a monomer of an epoxy compound having a structure represented by the following formula (1), a multimer in which at least two of the epoxy compounds are bonded, or a mixture of the monomer and the multimer There is provided a curable epoxy composition characterized by containing an epoxy component which is: at least one of an acrylic polymer having an epoxy group and a styrene polymer having an epoxy group, and a curing agent.

  In the above formula (1), R1 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a structure represented by the following formula (2), R2 represents an alkylene group having 1 to 5 carbon atoms, and R3 represents carbon. The alkylene group of number 1-5 is represented.

  In said formula (2), R4 represents a C1-C5 alkylene group.

  The anisotropic conductive material according to the present invention contains a curable epoxy composition constituted according to the present invention and conductive particles.

  The laminated body which concerns on this invention is equipped with the 1st connection object member and the semi-hardened material layer laminated | stacked on this 1st connection object member, and the said semi-hardened material layer is a said 1st connection object member. After coating the curable epoxy composition of the present invention or the anisotropic conductive material containing the curable epoxy composition and conductive particles, the curable epoxy composition or the anisotropic conductive material is applied. It is formed by pre-curing.

  The connection structure according to the present invention includes a first connection target member, a second connection target member, and a connection portion connecting the first and second connection target members, and the connection portion includes: It is formed by the anisotropic conductive material containing the curable epoxy composition of this invention or this curable epoxy composition, and electroconductive particle, It is characterized by the above-mentioned.

  The method for manufacturing a connection structure according to the present invention includes a step of laminating a second connection target member on the semi-cured product layer of the laminate configured according to the present invention, and laminating the second connection target member. Then, the semi-cured material layer is heated and cured to form a connection portion in which the semi-cured material layer is cured, and the first and second connection target members are connected by the connection portion. It is characterized by that.

  The curable epoxy composition according to the present invention is a monomer of an epoxy compound having the above specific structure, a multimer in which at least two epoxy compounds are bonded, or a mixture of the monomer and the multimer. It contains a certain epoxy component, at least one of an acrylic polymer having an epoxy group and a styrene polymer having an epoxy group, and a curing agent. Hardening does not proceed when stored in Furthermore, when the curable epoxy composition according to the present invention is stored in a semi-cured state and then used to connect the connection target members, the connection target members can be easily connected.

  Further, when the anisotropic conductive material according to the present invention is stored in a semi-cured state and then used for connection between electrodes of an electronic component, the electrodes of the electronic component can be easily connected.

  Details of the present invention will be described below.

(Curable epoxy composition)
The curable epoxy composition according to the present invention includes an epoxy compound monomer having a structure represented by the following formula (1), a multimer in which at least two epoxy compounds are bonded, or the monomer and the monomer. An epoxy component (hereinafter also referred to as epoxy component A) which is a mixture with a multimer, and at least one polymer (hereinafter also referred to as polymer B) of an acrylic polymer having an epoxy group and a styrene polymer having an epoxy group. And a curing agent. The epoxy component A is a monomer of an epoxy compound having a structure represented by the following formula (1), a multimer in which at least two epoxy compounds are bonded, or a mixture of the monomer and the multimer. Is one of the following.

  In the above formula (1), R1 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a structure represented by the following formula (2), R2 represents an alkylene group having 1 to 5 carbon atoms, and R3 represents carbon. The alkylene group of number 1-5 is represented.

  In said formula (2), R4 represents a C1-C5 alkylene group.

  When carbon number of the said alkyl group exceeds 5, the cure rate of a curable epoxy composition may fall. Moreover, when carbon number of the said alkylene group exceeds 5, the cure rate of a curable epoxy composition may fall.

  R1 in the above formula (1) is preferably an alkyl group having 1 to 3 carbon atoms or a structure represented by the above formula (2), and more preferably a structure represented by the above formula (2). preferable. The alkyl group may be an alkyl group having a straight chain structure or an alkyl group having a branched structure.

  R2 in the above formula (1) is preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a methylene group. R3 in the above formula (1) is preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a methylene group. The alkylene group may be an alkylene group having a straight chain structure or an alkylene group having a branched structure. R2 and R3 may be the same or different.

  R4 in the above formula (2) is preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a methylene group. The alkylene group may be an alkylene group having a straight chain structure or an alkylene group having a branched structure.

  The epoxy compound having the structure represented by the above formula (1) has a fluorene structure and at least two epoxy groups. The curable epoxy composition of the present invention contains the above-mentioned epoxy component A and at least one of an acrylic polymer having an epoxy group and a styrene polymer having an epoxy group, which will be described later, and is not completely cured. Appropriate tackiness when in a semi-cured state. Furthermore, even if the curable epoxy composition is stored in a semi-cured state, the curing hardly proceeds. When the curable epoxy composition is stored in a semi-cured state and then used for connection of the connection target member, the connection target member can be easily connected.

  Furthermore, when an anisotropic conductive material in which conductive particles are added to the curable epoxy composition of the present invention is stored in a semi-cured state and then used for connection between electrodes of an electronic component, the electrodes are easily connected. it can. Furthermore, the reliability of the electrical connection between the electrodes can be increased.

  Specific examples of the epoxy compound having the structure represented by the above formula (1) include an epoxy compound represented by the following formula (3). The epoxy compound represented by the following formula (3) has a structure in which R2 in the above formula (1) is a methylene group, R3 is a methylene group, and R1 is represented by the above formula (2). It is an epoxy compound in which R4 in the above formula (2) is a methylene group.

  The epoxy compound having the structure represented by the formula (1) described above is a monomer. In this invention, it replaces with the monomer of the epoxy compound which has a structure represented by the said Formula (1), or the epoxy compound which has a structure represented by the said Formula (1) with the monomer of this epoxy compound A multimer in which at least two are bonded may be used. The epoxy component A is a monomer of an epoxy compound having a structure represented by the above formula (1), a multimer in which 2 to 10 epoxy compounds are bonded, or the monomer and the multimer. It is preferably a mixture, more preferably a monomer of the above epoxy compound, a multimer in which two or three of the epoxy compounds are bonded, or a mixture of the monomer and the multimer. More preferably, it is a monomer of the epoxy compound. When a multimer in which more than 10 epoxy compounds having a structure represented by the above formula (1) are combined is used, the viscosity of the curable epoxy composition may be too high. In addition, when the monomer of the epoxy compound having the structure represented by the above formula (1) is synthesized, a multimer in which two or three of the monomers are combined may be included as a by-product. .

  In a total of 100% by weight of the epoxy component A and the polymer B, the epoxy component A is preferably contained within a range of 40 to 80% by weight, and contained within a range of 50 to 70% by weight. It is more preferable. If the content of the epoxy component A is too small, a cured product having a sufficiently low linear expansion coefficient may not be obtained. If the content of the epoxy component A is too large, the curable epoxy composition is semi-cured and may be easily cured when stored in a semi-cured state.

  The curable epoxy composition of the present invention includes at least one of an acrylic polymer having an epoxy group and a styrene polymer having an epoxy group. The styrene polymer having an epoxy group has a structure in which part of the benzene ring of polystyrene is substituted with an epoxy group.

  Since the curable epoxy composition of the present invention contains the polymer B together with the epoxy component A, the connection target member can be easily connected even if the connection target member is connected after being stored in a semi-cured state.

  The styrene polymer having an epoxy group preferably has a skeleton represented by the following formula (4). In this case, when the curable epoxy composition is semi-cured and stored in a semi-cured state, the curing becomes more difficult to proceed.

  In a total of 100% by weight of the epoxy component A and the polymer B, the polymer B is preferably contained within a range of 20 to 60% by weight, and contained within a range of 30 to 50% by weight. Is more preferable. If the content of the polymer B is too small, the curable epoxy composition is semi-cured and may be easily cured when stored in a semi-cured state. When there is too much content of the said polymer B, the hardened | cured material with a sufficiently low linear expansion coefficient may not be obtained.

  The weight average molecular weight of the acrylic polymer having an epoxy group is preferably in the range of 100,000 to 300,000, and more preferably in the range of 200,000 to 250,000. The weight average molecular weight of the styrene polymer having an epoxy group is preferably in the range of 10,000 to 100,000, and more preferably in the range of 15,000 to 50,000. When the weight average molecular weight is within the above range, the connection target member can be easily connected even if the connection target member is connected after the curable epoxy composition is stored in a semi-cured state.

  The epoxy equivalent of the polymer B is preferably in the range of 200 g / eq to 5000 g / eq, and more preferably in the range of 300 g / eq to 1000 g / eq.

  As a commercial product of the acrylic polymer having the epoxy group, Marproof G2050M and the like can be mentioned. Examples of commercially available styrene polymers having an epoxy group include Marproof G-0250S, Marproof G-1005S, Marproof G-1005SA and Marproof G-1010S (all of which are manufactured by NOF Corporation). The acrylic polymer having the epoxy group and the styrene polymer having the epoxy group may be used alone or in combination. Especially, since the adhesive force with respect to a circuit board is high, it is preferable to use the acrylic polymer which has the said epoxy group.

  The curable epoxy composition according to the present invention may contain an epoxy resin other than the epoxy component A and the polymer B, or an epoxy compound.

  The “epoxy resin” generally means a low molecular weight polymer or prepolymer having two or more epoxy groups in one molecule and having a molecular weight of 10,000 or less, or an epoxy group of the polymer or prepolymer. It is a curable resin produced by a ring-opening reaction. The curable resin may be a thermosetting resin or a photocurable resin.

  Specific examples of the epoxy resin include a bisphenol type epoxy resin, an epoxy novolac resin, and an epoxy resin having a naphthalene structure.

  Examples of commercially available epoxy compounds include Adeka Resin EP-3300S and Adeka Resin EP-3300E (all of which are manufactured by ADEKA). The curable epoxy composition preferably contains at least one of Adeka Resin EP-3300S and Adeka Resin EP-3300E, and more preferably contains Adeka Resin EP-3300S. By using these preferable commercial products, the viscosity of the curable epoxy composition can be adjusted.

  The chlorine concentration of the curable epoxy composition is preferably 500 ppm or less. If the chlorine concentration is too high, the curing rate of the curable epoxy composition may be slow. The chlorine concentration can be measured by, for example, ICP emission analysis.

  The said hardening | curing agent is not specifically limited. Examples of the curing agent include an imidazole curing agent, an amine curing agent, a phenol curing agent, and an acid anhydride curing agent. Among them, an imidazole curing agent or an amine curing agent is preferable because the curable epoxy composition can be cured more rapidly at a low temperature. Moreover, since the storage stability of the mixture of the said epoxy component A, the said polymer B, and the said hardening | curing agent can be improved, a latent hardening | curing agent is preferable. More preferably, the latent curing agent is a latent imidazole curing agent or a latent amine curing agent. These curing agents may be used alone or in combination of two or more. The curing agent may be coated with a polymer material such as polyurethane resin or polyester resin.

  The content of the curing agent is not particularly limited. It is preferable that the said hardening | curing agent is contained within the range of 1-40 weight part with respect to the total 100 weight part of all the epoxy components. When the amount of the curing agent is less than 1 part by weight, the curable epoxy composition may not be sufficiently cured. If the amount of the curing agent exceeds 40 parts by weight, the curing rate of the curable epoxy composition may not be controlled. “Total 100 parts by weight of all epoxy components” means that when epoxy components other than the epoxy component A and the polymer B are not included, the total of 100 weights of the epoxy component A and the polymer B Parts, and when the epoxy component other than the epoxy component A and the polymer B is included, it means a total of 100 parts by weight of the epoxy component A, the polymer B, and the other epoxy components.

  When the said hardening | curing agent is an imidazole hardening | curing agent, it is preferable that an imidazole hardening | curing agent contains in the range of 1-15 weight part with respect to a total of 100 weight part of all the said epoxy components. When the said hardening | curing agent is an amine hardening | curing agent, it is preferable that an amine hardening | curing agent contains in the range of 15-40 weight part with respect to a total of 100 weight part of all the said epoxy components.

  The curable epoxy composition according to the present invention preferably contains a solvent.

  The solvent is not particularly limited. For example, when the epoxy component A or the polymer B is solid, when the solvent is added to the solid epoxy component A or the polymer B (hereinafter also referred to as solid content), the solid content is dissolved in the solvent. For this reason, when a solvent is used, the dispersibility of the said solid content in a curable epoxy composition can be improved. The solvent is preferably an organic solvent. Examples of the organic solvent include methyl cellosolve, methyl ethyl ketone, cyclohexane, toluene, and ethylene glycol diacetate.

  The content of the solvent is not particularly limited. The solvent is preferably contained within a range of 10 to 65 parts by weight, and more preferably within a range of 15 to 60 parts by weight, based on a total of 100 parts by weight of all epoxy components. When the solvent is used within this range, a more uniform curable epoxy composition can be obtained.

  In order to adjust the viscosity of the curable epoxy composition or to prevent the applied curable epoxy composition from getting wet and spreading, the curable epoxy composition of the present invention may further contain a polymerizable compound. Good. The polymerizable compound is not particularly limited. As said polymeric compound, a crosslinkable compound or a non-crosslinkable compound is mentioned, for example. The said polymeric compound may be used independently and 2 or more types may be used together.

  The crosslinkable compound is not particularly limited. Specific examples of the crosslinkable compound include, for example, 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, glycerine methacrylate acrylate, pentaerythritol tri (meth) acrylate, trimethylol Propane trimethacrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, glycidyl (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate, etc. And the like.

  The non-crosslinkable compound is not particularly limited. Specific examples of the non-crosslinkable compound include, for example, 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, Examples include decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, and tetradecyl (meth) acrylate.

  The polymerizable compound is preferably contained within a range of 10 to 60 parts by weight with respect to a total of 100 parts by weight of all the epoxy components. When the content of the polymerizable compound is less than 10 parts by weight, the viscosity of the curable epoxy composition may not be adjusted. When content of the said polymeric compound exceeds 60 weight part, the viscosity of a curable epoxy composition may become high too much.

  The curable epoxy composition of the present invention preferably contains an adhesive strength modifier. When the adhesive strength modifier is used, the adhesive strength of the cured product of the curable epoxy composition can be increased. The adhesive strength adjusting agent is preferably a silane coupling agent.

  The silane coupling agent is not particularly limited. Examples of the silane coupling agent include N-phenyl-3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, and N- (2-aminoethyl) -3-amino. Propylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyldimethylethoxysilane, 3-amino Propylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, vinyltrichlorosilane, 3-glycidoxypropyltrimethoxysilane , 3-g Sidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, dodecyltri Examples include ethoxysilane, hexyltrimethoxysilane, isobutyldiethoxysilane, methylphenyldiethoxysilane, and methylphenyldimethoxysilane. The said silane coupling agent may be used independently and 2 or more types may be used together.

  It is preferable that the said silane coupling agent is contained within the range of 4-20 weight part with respect to 100 weight part in total of all the said epoxy components. When the content of the silane coupling agent is less than 4 parts by weight, the adhesive strength of the cured product of the curable epoxy composition may be reduced. When content of the said silane coupling agent exceeds 20 weight part, a curable epoxy composition may become difficult to harden | cure.

  The curable epoxy composition of the present invention preferably contains inorganic particles. By using the inorganic particles, the thermal expansion of the cured product of the curable epoxy composition can be suppressed. The inorganic particles are not particularly limited. Examples of the inorganic particles include silica, aluminum nitride, and alumina. An inorganic particle may be used independently and 2 or more types may be used together.

  The inorganic particles are preferably contained within a range of 3 to 900 parts by weight with respect to a total of 100 parts by weight of all the epoxy components. When inorganic particles are used within this range, the thermal expansion of the cured product of the curable epoxy composition can be further suppressed.

  The curable epoxy composition of the present invention may contain a polymerization initiator that generates reactive species by light irradiation or heating. By using the polymerization initiator, the curing rate of the curable epoxy composition can be increased.

  The said polymerization initiator is not specifically limited. Examples of the polymerization initiator include acetophenone polymerization initiators, ketal polymerization initiators, halogenated ketones, acyl phosphinoxides, and acyl phosphonates. The acetophenone polymerization initiator is not particularly limited. Specific examples of the acetophenone polymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, methoxyacetophenone, Examples include 2,2-dimethoxy-1,2-diphenylethane-1-one and 2-hydroxy-2-cyclohexylacetophenone. The ketal polymerization initiator is not particularly limited. Specific examples of the ketal polymerization initiator include benzyldimethyl ketal. These polymerization initiators may be used independently and 2 or more types may be used together.

  The polymerization initiator is preferably contained within a range of 2 to 10 parts by weight with respect to a total of 100 parts by weight of all the epoxy components. If the content of the polymerization initiator is less than 2 parts by weight, the effect of adding the polymerization initiator may not be sufficiently obtained. When content of the said polymerization initiator exceeds 10 weight part, the adhesive force of the hardened | cured material of a curable epoxy composition may fall.

  The manufacturing method of the curable epoxy composition of this invention is not specifically limited. As a specific example of the method for producing a curable epoxy composition, the epoxy component A, the polymer B, and the solvent are mixed to prepare an epoxy composition, and then the curing agent is added to the epoxy composition. The manufacturing method which mix | blends with the other component added as needed, and mixes using a planetary stirrer etc. is mentioned.

  The curable epoxy composition of the present invention can be used as a one-component adhesive for bonding liquid crystal panels, semiconductor chips, and the like. The curable epoxy composition of the present invention may be a paste-like adhesive or a film-like adhesive.

  The method for processing the curable epoxy composition of the present invention into a film adhesive is not particularly limited. For example, a method of applying the curable epoxy composition of the present invention to a substrate such as a release paper and processing it into a film-like adhesive, or a substrate such as a release paper of the curable epoxy composition of the present invention containing a solvent. And a method of evaporating the solvent at a temperature lower than the activation temperature of the curing agent and processing it into a film-like adhesive.

  As a method of curing the curable epoxy composition of the present invention, a method of heating the curable epoxy composition, a method of irradiating the curable epoxy composition with light, and then heating the curable epoxy composition, or curable The method etc. which heat a curable epoxy composition simultaneously with irradiating light to an epoxy composition are mentioned.

  The heating temperature for curing the curable epoxy composition of the present invention is preferably in the range of 100 to 250 ° C, and more preferably in the range of 160 to 200 ° C. Since the curable epoxy composition of the present invention can be cured at a low temperature, the amount of energy required for heating can be reduced.

  Among the methods of curing the curable epoxy composition of the present invention, the method of irradiating the curable epoxy composition with light and then heating the curable epoxy composition cures more than the method using only heating. The curable epoxy composition can be cured in a short time.

  The light source used when irradiating light to the curable epoxy composition of this invention 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 a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excitation mercury lamp, or a metal halide lamp. Of these, a chemical lamp is preferable. The chemical lamp efficiently emits light in the active wavelength region of the polymerization initiator and emits less light in the light absorption wavelength region of the composition components other than the polymerization initiator. Furthermore, when a chemical lamp is used, light can efficiently reach the polymerization initiator present in the composition.

For example, when a cleavage type polymerization initiator having an acetophenone group is contained, the light irradiation intensity in the wavelength region of 365 nm to 420 nm is preferably in the range of 0.1 to 100 mW / cm ² .

(Anisotropic conductive material)
An anisotropic conductive material can be obtained by including conductive particles in the curable epoxy composition of the present invention.

  The conductive particles electrically connect, for example, electrodes of electronic components. The conductive particles are not particularly limited as long as at least the surface has conductivity. Examples of the conductive particles include conductive particles obtained by coating the surfaces of organic particles, inorganic particles, organic-inorganic hybrid particles, metal particles, and the like with a metal layer, or metal particles that are substantially composed of only metal. . 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.

  It is preferable that the said electroconductive particle is contained within the range of 0.5-5 weight part with respect to a total of 100 weight part of all the said epoxy components. If the amount of the conductive particles is less than 0.5 parts by weight, the electrodes or the like may not be reliably conducted. When content of the said electroconductive particle exceeds 5 weight part, the short circuit between adjacent electrodes may arise.

  The chlorine concentration of the anisotropic conductive material is preferably 500 ppm or less. When the said chlorine concentration is too high, the cure rate of the curable epoxy composition contained in the anisotropic conductive material may become slow.

  The anisotropic conductive material according to the present invention can be used as an anisotropic conductive paste, anisotropic conductive ink, anisotropic conductive adhesive, anisotropic conductive film or anisotropic conductive sheet. When the anisotropic conductive material is used as a film-like adhesive such as an anisotropic conductive film or anisotropic conductive sheet, the film-like adhesive containing the conductive particles and the conductive particles are contained. A film-like adhesive that is not used may be laminated.

(Laminate)
In FIG. 1, sectional drawing of the laminated body which concerns on one Embodiment of this invention is shown.

  The laminated body 1 shown in FIG. 1 is provided with the 1st connection object member 2 and the semi-hardened material layer 3 laminated | stacked on the upper surface 2a of the 1st connection object member 2. As shown in FIG. An electrode 2 b is formed on the upper surface 2 a of the first connection target member 2. The semi-cured product layer 3 contains conductive particles 4. The semi-cured material layer 3 is formed by applying an anisotropic conductive material containing a curable epoxy composition and conductive particles 4 to the upper surface 2a of the first connection target member 2, and then applying the anisotropic conductive material. It is formed by pre-curing. Instead of the anisotropic conductive material containing the curable epoxy composition and the conductive particles 4, the curable epoxy composition not containing the conductive particles 4 may be used.

  “Pre-curing” refers to semi-curing the curable epoxy composition without completely curing it. The semi-cured state may be referred to as a B stage state. The cured product layer can be formed by further proceeding the curing of the semi-cured product layer. The semi-cured product layer is a layer that is not completely cured. The semi-cured product layer is a layer that can be further cured.

(Connection structure)
FIG. 2 shows a cross-sectional view of a connection structure according to an embodiment of the present invention.

  A connection structure 11 shown in FIG. 2 can be formed using the laminate 1.

  The connection structure 11 shown in FIG. 2 includes a first connection target member 2, a second connection target member 12, and a connection portion 3 </ b> A connecting the first and second connection target members 2 and 12. Prepare. The connection portion 3A is formed by curing the semi-cured product layer 3. An electrode 12 b is formed on the lower surface 12 a of the second connection target member 12. The electrodes 2 b and 12 b of the first and second connection target members 2 and 12 are connected by the conductive particles 4.

  Specifically, as the connection structure 11, an electronic component chip such as a semiconductor chip, a capacitor chip, or a diode chip is mounted on a circuit board, and an electrode of the electronic component chip is electrically connected to an electrode on the circuit board. Connection structure etc. which are connected in general. Examples of circuit boards include various printed boards such as flexible printed boards, glass boards, and various circuit boards such as boards on which metal foils are laminated.

  The manufacturing method of the connection structure 11 is not specifically limited. Specific examples of the manufacturing method of the connection structure 11 include the following first and second manufacturing methods.

  As a first manufacturing method, a laminate 1 in which a curable epoxy composition of the present invention or a semi-cured product layer 3 formed of the curable epoxy composition is laminated on an upper surface 2a of a first connection target member 2. A step of laminating the second connection target member 12 on the upper surface 3a of the semi-cured product layer 3 and a step of heating and curing the semi-cured product layer 3 after laminating the second connection target member 12. The manufacturing method provided is mentioned. By curing the semi-cured product layer 3, a connection portion 3A in which the semi-cured product layer 3 is cured is formed. The connection portion 3A is a cured product layer obtained by curing the semi-cured product layer 3. The first and second connection target members 2 and 12 are connected by the connecting portion 3A.

  As a second manufacturing method, the curable epoxy composition of the present invention or the curable epoxy composition and the conductive particles are different between the first connection target member 2 and the second connection target member 12. Examples include a manufacturing method including a step of disposing an anisotropic conductive material and a step of curing the curable epoxy composition or the anisotropic conductive material. In the second manufacturing method, the curable epoxy composition or the anisotropic conductive material is preferably cured in one step without being semi-cured to form the connection portion 3A. The first and second connection target members 2 and 12 are connected by the connecting portion 3A.

  Of the first and second manufacturing methods of the connection structure 11, the first manufacturing method is preferable.

  In the first manufacturing method, the upper surface 2a of the first connection target member 2 is coated with the curable epoxy composition of the present invention or an anisotropic conductive material containing the curable epoxy composition and conductive particles. And a step of forming a semi-cured product layer 3 on the upper surface 2a of the first connection target member 2 by pre-curing the curable epoxy composition or anisotropic conductive material. Good.

  In the first manufacturing method, as a method of applying a curable epoxy composition or an anisotropic conductive material to the upper surface 2a of the first connection target member 2, an electrode of the first connection target member 2 is formed. A method of applying a paste-like curable epoxy composition or an anisotropic conductive material on the coated surface, or a film-shaped curable epoxy composition or a different surface on the surface on which the electrode of the first connection target member 2 is formed. For example, a method of attaching an isotropic conductive material may be used.

  In the said 1st manufacturing method, the temperature at the time of preheating the semi-hardened material layer 3 is not specifically limited. The preheating temperature is set to a temperature at which the curable epoxy composition or the anisotropic conductive material is not completely cured. It is preferable that the solvent is not completely removed during the preheating.

  When a conventional anisotropic conductive material is stored in a semi-cured state that is not completely cured, the curing reaction easily proceeds in a short time. For this reason, when the conventional anisotropic conductive material is stored in a semi-cured state that is not completely cured and then used for connection of the connection target member, the connection target member may not be reliably connected.

  When the curable epoxy composition or anisotropic conductive material of the present invention is stored in a semi-cured state that is not completely cured as compared with the conventional curable epoxy composition or anisotropic conductive material, Curing is difficult to proceed. For this reason, when it uses for the connection of a connection object member after storing the curable epoxy composition or anisotropic conductive material of this invention in a semi-hardened state, a connection object member can be connected easily.

  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
40 parts by weight of the epoxy compound represented by the above formula (3) as the epoxy component A, a styrene polymer having the epoxy group (weight average molecular weight 20000, epoxy equivalent 310 g / eq, “Marproof G-0250S manufactured by NOF Corporation) ”) 160 parts by weight of a mixture containing 60 parts by weight of ethylene glycol diacetate as the solvent was dissolved at 160 ° C. while refluxing to obtain a resin composition.

  In the obtained resin composition, 15 parts by weight of an amine adduct type curing agent (“PN-23J” manufactured by Ajinomoto Fine Techno Co.) as a curing agent and N-phenyl-3-aminopropyltrimethoxy as a silane coupling agent 6 parts by weight of silane and 2 parts by weight of conductive particles having an average particle diameter of 3 μm were added and stirred for 8 minutes at 2000 rpm using a planetary stirrer to obtain a curable composition. The conductive particles 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. there were.

  The obtained curable composition was filtered through a nylon filter paper (pore diameter: 10 μm) to produce an anisotropic conductive material.

(Example 2)
The above styrene polymer having an epoxy group (weight average molecular weight 20000, epoxy equivalent 310 g / eq, “Marproof G-0250S” manufactured by NOF Corporation) and an acrylic polymer having an epoxy group (weight average molecular weight 200000, epoxy equivalent 340 g / eq) An anisotropic conductive material was produced in the same manner as in Example 1 except that it was changed to “Marproof G-2050M” manufactured by NOF Corporation.

(Comparative Example 1)
40 parts by weight of the epoxy compound represented by the above formula (3) as the epoxy component A and a styrene polymer having the epoxy group (weight average molecular weight 20000, epoxy equivalent 310 g / eq, “Marproof G-0250S” manufactured by NOF Corporation) ]) An anisotropic conductive material was produced in the same manner as in Example 1 except that 60 parts by weight was changed to 100 parts by weight of bisphenol A type epoxy resin.

(Evaluation)
A glass substrate (length 3 cm × width 4 cm) on which a copper electrode (line / space = 10 μm / 10 μm) was formed was prepared.

  The anisotropic conductive materials obtained in Examples 1 and 2 and Comparative Example 1 were coated on the glass substrate so as to have a thickness of 50 μm, and an anisotropic conductive material layer was formed on the glass substrate.

  A glass substrate on which an anisotropic conductive material layer is formed is preheated at 110 ° C. for 20 minutes to semi-cure the anisotropic conductive material layer on the glass substrate, so that the anisotropic state of the semi-cured state on the glass substrate A conductive conductive material layer was formed. Thereafter, the glass substrate on which the semi-cured anisotropic conductive material layer was formed was stored for 3 days in an environment of room temperature of 25 ° C. and humidity of 50%.

  The anisotropic conductive material layer formed of the anisotropic conductive material of Examples 1 and 2 remained in a semi-cured state after being stored for 3 days. The anisotropic conductive material layer formed of the anisotropic conductive material of Comparative Example 1 was cured after being stored for 3 days.

  An IC chip (length 2 mm × width 2 cm) having an ITO electrode (line / space = 10 μm / 10 μm) formed on the lower surface was prepared. After the IC chip was laminated on the anisotropic conductive material layer on the glass substrate so that the electrodes face each other, the connection structure was produced by heating at 190 ° C. for 10 seconds.

  When the anisotropic conductive materials of Examples 1 and 2 were used, the glass substrate and the IC chip were simply heated at 190 ° C. for 10 seconds after preheating and after being stored in a semi-cured state for 3 days. It was easy to connect.

  In the case where the anisotropic conductive material of Comparative Example 1 was used, the circuit board and the IC chip could not be connected because the semi-cured material layer had been cured after being preheated and stored for 3 days.

FIG. 1 is a cross-sectional view of a laminate according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a connection structure according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laminated body 2 ... 1st connection object member 2a ... Upper surface 2b ... Electrode 3 ... Semi-hardened material layer 3a ... Upper surface 3A ... Connection part 4 ... Conductive particle 11 ... Connection structure 12 ... 2nd connection object member 12a ... Lower surface 12b ... Electrode

Claims (6)

An epoxy compound monomer having a structure represented by the following formula (1), a multimer in which at least two epoxy compounds are bonded, or an epoxy component that is a mixture of the monomer and the multimer;
At least one of an acrylic polymer having an epoxy group and a styrene polymer having an epoxy group;
A curable epoxy composition comprising a curing agent.

In the above formula (1), R1 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a structure represented by the following formula (2), R2 represents an alkylene group having 1 to 5 carbon atoms, and R3 represents carbon. The alkylene group of number 1-5 is represented.

In said formula (2), R4 represents a C1-C5 alkylene group. The epoxy component is contained within a range of 40 to 80% by weight in a total of 100% by weight of the epoxy component and at least one of the acrylic polymer having the epoxy group and the styrene polymer having the epoxy group, The curable epoxy composition according to claim 1, comprising at least one of the acrylic polymer having an epoxy group and the styrene polymer having an epoxy group in a range of 20 to 60% by weight. An anisotropic conductive material containing the curable epoxy composition according to claim 1 or 2 and conductive particles. A first connection target member, and a semi-cured material layer laminated on the first connection target member,
The said semi-hardened | cured material layer contains the curable epoxy composition of Claim 1 or 2 on the said 1st connection object member, or the anisotropic conductive material containing this curable epoxy composition and electroconductive particle. A layered product formed by pre-curing the curable epoxy composition or the anisotropic conductive material after coating. A first connection target member, a second connection target member, and a connection portion connecting the first and second connection target members;
The connection portion is formed of an anisotropic conductive material containing the curable epoxy composition according to claim 1 or 2 or the curable epoxy composition and conductive particles, Structure. The step of laminating the second connection target member on the semi-cured product layer of the laminate according to claim 4 ;
After laminating the second connection target member, the semi-cured material layer is heated and cured to form a connection portion where the semi-cured material layer is cured, and the first and second connection portions are formed by the connection portion. And a step of connecting the members to be connected.

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