JP2015004056A - Curable composition for electronic component and connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition for electronic components which can be cured quickly, and also can improve the moist heat resistance of a cured product.SOLUTION: A curable composition for electronic components according to the present invention comprises an epoxy compound not having a radical-polymerizable group, a curable compound having an epoxy group and a radical-polymerizable group, a latent epoxy curing agent, a photo- or thermal-radical polymerization agent, and a compound having two or more thiol groups.

Description

  The present invention relates to a curable composition for an electronic component comprising an epoxy compound and a curing agent. Moreover, this invention relates to the connection structure using the said curable composition for electronic components.

  The epoxy resin composition has properties that the cured product has high adhesive strength and is excellent in water resistance and heat resistance of the cured product. For this reason, epoxy resin compositions are widely used in various applications such as electronics, architecture, and vehicles. Moreover, in order to electrically connect various connection object members, conductive particles may be blended in the epoxy resin composition. The epoxy resin composition containing conductive particles is called an anisotropic conductive material.

  The anisotropic conductive material is 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 disposing an anisotropic conductive material between the electrode of the IC chip and the electrode of the circuit board, these electrodes can be electrically connected by conductive particles by heating and pressing.

  As an example of the epoxy resin composition, the following Patent Document 1 includes (1) an epoxy resin, (2) an acrylic ester monomer, an acrylic ester oligomer, a methacrylic ester monomer or a methacrylic ester oligomer, and (3 A composition comprising a latent epoxy curing agent, (4) a radical photopolymerization initiator, and (5) a compound having two or more thiol groups is disclosed. In 100% by weight of the composition, (5) the content of the compound having two or more thiol groups is 0.001 to 5 parts by weight. Patent Document 1 proposes to use the above composition as a liquid crystal sealant composition.

  Patent Document 2 below discloses a composition comprising a curing agent that generates free radicals, a radical polymerizable substance, and a compound having a secondary thiol group. The molecular weight of the compound having a secondary thiol group is 400 or more and less than 2000. Patent Document 2 describes that the composition may contain conductive particles, and describes that the composition is used as a circuit connection material. In the examples of Patent Document 2, bisphenol A / F copolymer phenoxy resin, polyurethane resin, styrene-maleic anhydride copolymer, urethane acrylate oligomer, dicyclopentadiene diacrylate, 2- Methacryloyloxyethyl acid phosphate, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione; Circuit connection materials containing 5-dimethyl-2,5-di (2-ethylhexanoyl) hexane and Ni powder are described.

WO2005 / 052021A1 JP 2012-146888 A

  In recent years, in order to efficiently connect electrodes of electronic components, it has been required to shorten the heating time required for curing the composition. By shortening the heating time, thermal deterioration of the obtained electronic component can be suppressed.

  A composition containing a compound having a radical polymerizable group such as a (meth) acryloyl group can be thermally cured relatively quickly. However, the resulting cured product may have low heat and humidity resistance.

  An object of the present invention is to provide a curable composition for electronic parts that can be cured quickly and can further improve the moisture and heat resistance of the cured product, and a connection using the curable composition for electronic parts. It is to provide a structure.

  According to a wide aspect of the present invention, an epoxy compound having no radical polymerizable group, a curable compound having an epoxy group and a radical polymerizable group, a latent epoxy curing agent, a light or thermal radical polymerization initiator, There is provided a curable composition for electronic parts, comprising a compound having two or more thiol groups.

  On the specific situation with the curable composition for electronic components which concerns on this invention, this curable composition for electronic components contains electroconductive particle.

  On the specific situation with the curable composition for electronic components which concerns on this invention, the said electroconductive particle is an electroconductive particle which has a solder on the electroconductive outer surface.

  On the specific situation with the curable composition for electronic components which concerns on this invention, the said electroconductive particle is a solder particle.

  On the specific situation with the curable composition for electronic components which concerns on this invention, it is used for the electrical connection of the electrode whose electrode width is 80 micrometers or less.

  On the specific situation with the curable composition for electronic components which concerns on this invention, the weight average molecular weight of the said curable compound is 500-150,000.

  On the specific situation with the curable composition for electronic components which concerns on this invention, the said radically polymerizable group of the said curable compound is a (meth) acryloyl group.

  In a specific aspect of the curable composition for electronic parts according to the present invention, the curable compound reacts a reaction product of bisphenol F and 1,6-hexanediol with a compound having a radical polymerizable group. Is obtained.

  According to a wide aspect of the present invention, a first connection target member, a second connection target member, and a connection portion connecting the first connection target member and the second connection target member. A connection structure is provided in which the connection portion is formed by curing the curable composition for electronic components described above.

  On the specific situation with the connection structure which concerns on this invention, the said curable composition for electronic components contains electroconductive particle, a said 1st connection object member has a 1st electrode on the surface, said 2nd The connection target member has a second electrode on the surface, and the first electrode and the second electrode are electrically connected by the conductive particles.

  On the specific situation with the connection structure which concerns on this invention, a said 1st electrode width and a said 2nd electrode width are 80 micrometers or less.

  The curable composition for electronic components according to the present invention includes an epoxy compound having no radical polymerizable group, a curable compound having an epoxy group and a radical polymerizable group, a latent epoxy curing agent, and a light or thermal radical. Since it contains a polymerization initiator and a compound having two or more thiol groups, it can be quickly cured. Furthermore, the moisture and heat resistance of the cured product can be increased.

FIG. 1 is a cross-sectional view schematically showing a connection structure using a curable composition for electronic parts according to an embodiment of the present invention. 2A to 2C are cross-sectional views for explaining each step of obtaining a connection structure using the curable composition for electronic components according to one embodiment of the present invention. FIG. 3 is a diagram showing an NMR chart of the compound represented by the formula (2) obtained in Synthesis Example 1. FIG. 4 is a cross-sectional view showing an example of conductive particles. FIG. 5 is a cross-sectional view showing a first modification of the conductive particles. FIG. 6 is a cross-sectional view showing a second modification of the conductive particles.

  Details of the present invention will be described below.

(Curable composition for electronic parts)
The curable composition for electronic parts according to the present invention (hereinafter sometimes abbreviated as curable composition) includes an epoxy compound having no radical polymerizable group, and a curable composition having an epoxy group and a radical polymerizable group. A compound, a latent epoxy curing agent, a light or thermal radical polymerization initiator, and a compound having two or more thiol groups. The said curable composition is used for an electronic component. The said curable composition is used suitably for the connection of an electronic component. It is preferable that the said curable composition is a connection material for electronic components.

  Since the curable composition for electronic components according to the present invention has the above-described composition, it can be cured quickly. Furthermore, the moisture and heat resistance of the cured product can be increased. Moreover, the thermal shock resistance of the cured product can be improved. In addition, when a UV or heat B-stage is used, even if the UV irradiation conditions and temperature conditions vary, a constant B-stage state can be obtained. , Voids can be made difficult to occur.

  The curable composition for electronic components according to the present invention preferably contains conductive particles. In a connection structure in which electrodes are electrically connected by conductive particles, it is very important to have high conductivity and high heat and humidity resistance. The curable composition for electronic parts according to the present invention includes an epoxy compound having no radical polymerizable group, a curable compound having an epoxy group and a radical polymerizable group, a latent epoxy curing agent, and a light or thermal radical. By including a polymerization initiator, a compound having two or more thiol groups, and conductive particles, the conductivity and wet heat resistance are sufficiently enhanced in a connection structure in which electrodes are electrically connected by conductive particles. be able to.

  In the curable composition for electronic parts according to the present invention, the conductive particles are preferably conductive particles having solder on the conductive outer surface, and more preferably solder particles. The curable composition for electronic parts according to the present invention has the above-described composition, and thus can be cured quickly. However, when the curing rate is increased, a region having no electrode (space (S)) when the connection structure is produced. Once the conductive particles are disposed on the conductive structure, the conductive particles tend to remain disposed in a region where there is no electrode in the obtained connection structure. If the conductive particles are conductive particles having a solder on the outer surface of the conductive particles, even if the conductive particles are once arranged in a region (space (S)) where there is no electrode when the connection structure is manufactured, the conductive particles Can easily move to a certain area (line (L)), and as a result, the number of conductive particles arranged on the upper and lower electrodes to be connected can be increased, and in the lateral direction that should not be connected The number of conductive particles arranged between adjacent electrodes can be reduced. As a result, by using conductive particles having solder on the conductive outer surface, the particles can be cured quickly, and the conductivity and heat and humidity resistance can be effectively increased. In particular, when the conductive particles are solder particles, the conductive particles can be quickly cured, and the conduction reliability and heat-and-moisture resistance can be further effectively improved. In particular, when electrically connecting electrodes having a small electrode width, the use of conductive particles or solder particles having solder on the conductive outer surface can significantly increase conduction reliability and moisture and heat resistance. it can.

  Hereinafter, the detail of each component contained in the curable composition for electronic components which concerns on this invention is demonstrated.

[Epoxy compound]
The epoxy compound has an epoxy group. The said epoxy compound does not have a radically polymerizable group. As for the said epoxy compound, only 1 type may be used and 2 or more types may be used together.

  The above epoxy compounds include bisphenol type epoxy compounds, phenol novolac type epoxy compounds, biphenyl novolac type epoxy compounds, biphenol type epoxy compounds, resorcin type epoxy compounds, naphthalene type epoxy compounds, fluorene type epoxy compounds, phenol aralkyl type epoxy compounds, naphthol. Aralkyl epoxy compounds, dicyclopentadiene epoxy compounds, anthracene epoxy compounds, epoxy compounds having an adamantane skeleton, epoxy compounds having a tricyclodecane skeleton, polyether epoxy compounds, aliphatic epoxy compounds, and triazine skeletons The epoxy compound etc. which are contained in are mentioned. Examples of the bisphenol type epoxy compound include a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, and a bisphenol S type epoxy compound.

[Curable compound]
The curable compound has an epoxy group and a radical polymerizable group. As for the said sclerosing | hardenable compound, only 1 type may be used and 2 or more types may be used together.

  The radical polymerizable group means a group capable of addition polymerization by a radical. Examples of the radical polymerizable group include a group containing an unsaturated double bond. Specific examples of the radical polymerizable group include allyl group, isopropenyl group, maleoyl group, styryl group, vinylbenzyl group, (meth) acryloyl group and vinyl group. The (meth) acryloyl group means an acryloyl group and a methacryloyl group.

  From the viewpoint of further improving the fast curability of the composition and the heat and moisture resistance of the cured product, the radical polymerizable group preferably has a vinyl group, and more preferably a (meth) acryloyl group. When the radical polymerizable group is a (meth) acryloyl group, the radical polymerizable group has a vinyl group.

  From the viewpoint of further improving the quick curability of the composition, the curable compound preferably has an epoxy group at both ends. From the viewpoint of further improving the heat and moisture resistance of the cured product, the curable compound preferably has a vinyl group in the side chain, and preferably has a (meth) acryloyl group.

  From the viewpoint of further improving the rapid curability of the composition and the heat and moisture resistance of the cured product, the weight average molecular weight of the epoxy compound is preferably 500 or more, more preferably 1000 or more, preferably 150,000 or less, more preferably 50000 or less. More preferably, it is 15000 or less.

  The peak molecular weight of the epoxy compound is preferably 5000 or more, more preferably 10,000 or more, preferably 50000 or less, more preferably 30000 or less.

  It is preferable that both the polymerization average molecular weight and the peak molecular weight are in the preferable ranges described above. Thereby, both the adhesive force and semi-curability by UV and the suppression of voids can be achieved.

  The weight average molecular weight and peak molecular weight of the epoxy compound indicate the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

  The epoxy compound is more preferably a reaction product using a diol compound and a compound having two epoxy groups. The epoxy compound is obtained by reacting a hydroxyl group of a reaction product of a diol compound and a compound having two epoxy groups with a compound having a functional group capable of reacting with a hydroxyl group and having a radical polymerizable group, or a diol. It is preferably obtained by reacting a compound having a functional group capable of reacting with an epoxy group and a compound having a radical polymerizable group at both terminal epoxy groups of a reaction product of the compound and a compound having two epoxy groups. . In addition, even when using a curable compound having an epoxy group and a radical polymerizable group other than these curable compounds having an epoxy group and a radical polymerizable group, a curable compound having an epoxy group and a radical polymerizable group is used. , Epoxy compounds that do not have radically polymerizable groups, latent epoxy curing agents, light or thermal radical polymerization initiators, and compounds that have two or more thiol groups, compared to when they are not used together Thus, the effect of the present invention is more excellent.

  The epoxy compound preferably has one or more vinyl groups in the side chain, and more preferably has two or more vinyl groups in the side chain in total. As the number of vinyl groups increases, the heating time can be further shortened, and the adhesiveness and heat-and-moisture resistance of the cured product can be further improved. The introduction rate of the vinyl group is preferably 5% or more, more preferably 10% or more, preferably 60% or less, more preferably 40%, based on the number of side chain hydroxyl groups (number of side chain hydroxyl groups before reaction: 100%). It is as follows.

  In addition, when a B-stage is formed by UV or heat, it becomes easy to control the degree of B-stage by the amount of thiol compound added, and the influence on the degree of B-stage due to variations in UV irradiation conditions and temperature conditions is reduced. It is possible.

  The epoxy compound is preferably a reaction product of a compound having two or more phenolic hydroxyl groups and a compound having two or more epoxy groups.

  Examples of the compound having two or more phenolic hydroxyl groups include bisphenol compounds, resorcinol and naphthalenol. Examples of the bisphenol compound include bisphenol F, bisphenol A, bisphenol S, bisphenol SA, and bisphenol E.

  Examples of the curable compound having two or more epoxy groups include aliphatic epoxy compounds and aromatic epoxy compounds. Examples of the aliphatic epoxy compound include a compound having a glycidyl ether group at both ends of an alkyl chain having 3 to 12 carbon atoms, and a polyether skeleton having 2 to 4 carbon atoms. Examples thereof include polyether type epoxy compounds having structural units bonded continuously.

  The epoxy compound has a radical polymerizable group in a reaction product of bisphenol F or resorcinol and 1,6-hexanediol diglycidyl ether or resorcinol diglycidyl ether (hereinafter sometimes referred to as a reaction product X). It is preferably obtained by reacting a compound. In this reaction, the reaction is performed so that the radical polymerizable group remains.

  The compound having a radical polymerizable group is a compound having a (meth) acryloyl group and a carboxyl group, a compound having a (meth) acryloyl group and an isocyanate group, or a compound having a (meth) acryl group and an epoxy group. It is preferable. Preferable specific examples of the compound having a radical polymerizable group include (meth) acrylic acid, 2- (meth) acryloyloxyethyl isocyanate and 4-hydroxybutyl glycidyl ether. In the curable compound synthesized using such a compound, it can be cured more rapidly, and the adhesiveness and heat-and-moisture resistance of the cured product can be further enhanced. The compound having a radical polymerizable group is more preferably (meth) acrylic acid or (meth) acryloyloxyethyl isocyanate.

  Examples of the reactant X include a first reactant of bisphenol F and 1,6-hexanediol diglycidyl ether, a second reactant of resorcinol and 1,6-hexanediol diglycidyl ether, resorcinol and resorcinol di A third reaction product with glycidyl ether and a fourth reaction product with bisphenol F and resorcinol diglycidyl ether can be mentioned.

  The first reaction product has a structural unit in which the skeleton derived from bisphenol F and the skeleton derived from 1,6-hexanediol diglycidyl ether are bonded to the main chain, and 1,6-hexanediol diglycidyl. It has an epoxy group derived from ether at both ends. The second reaction product has a structural unit derived from resorcinol and a structural unit derived from 1,6-hexanediol diglycidyl ether in the main chain, and is derived from 1,6-hexanediol diglycidyl ether. It has an epoxy group at both ends. The third reaction product has a skeleton derived from resorcinol and a skeleton derived from resorcinol diglycidyl ether in the main chain, and has an epoxy group derived from resorcinol diglycidyl ether at both ends. The fourth reaction product has a skeleton derived from bisphenol F and a skeleton derived from resorcinol diglycidyl ether in the main chain, and an epoxy group derived from resorcinol diglycidyl ether at both ends.

  From the viewpoint of easy synthesis, allowing the curable compound to be cured more rapidly, and further enhancing the adhesion and moisture resistance of the cured product, the first, second, third, and fourth described above. Among the reactants, the first reactant, the second reactant, or the third reactant is preferable. The reactant X is preferably the first reactant, preferably the second reactant, and further preferably the third reactant.

  The content of the curable compound is preferably 10 parts by weight or more with respect to a total of 100 parts by weight of the epoxy compound having no radical polymerizable group and the curable compound having the epoxy group and the radical polymerizable group. More preferably, it is 30 parts by weight or more, preferably 90 parts by weight or less, more preferably 70 parts by weight or less. When the content of the curable compound is not less than the above lower limit and not more than the above upper limit, the B-staged state, fast curability, and moist heat resistance of the cured product are improved in good balance.

[Latent epoxy curing agent]
The latent epoxy curing agent advances curing of a compound having an epoxy group. The latent epoxy curing agent is not particularly limited. As the latent epoxy curing agent, a known latent epoxy curing agent can be used. As for the said latent epoxy hardening | curing agent, only 1 type may be used and 2 or more types may be used together.

  Preferable examples of the latent epoxy curing agent include organic acid dihydrazide compounds, imidazole compounds and amine compounds. Latent epoxy compounds other than these may be used. Examples of the amine compound include dicyandiamide and aromatic amine compounds. As for the said latent epoxy hardening | curing agent, only 1 type may be used and 2 or more types may be used together.

  The latent epoxy curing agent is preferably an amine compound. The nucleophilic addition property by heat of the active hydrogen of the amine compound to the radical polymerizable group of the curable compound is good.

  The melting point of the latent epoxy curing agent is preferably 100 ° C. or higher. The softening point temperature of the latent epoxy curing agent by the ring and ball method is preferably 100 ° C. or higher. When these temperatures are 100 ° C. or higher, the storage stability of the curable composition is improved, and the curable composition can be used for a long time, for example, during coating.

  Specific examples of the latent epoxy curing agent include dicyandiamides such as cyandiamide (melting point 209 ° C), adipic acid dihydrazide (melting point 181 ° C), 1,3-bis (hydrazinocarbonoethyl) -5-isopropyl. Organic acid dihydrazide such as hydantoin (melting point 120 ° C.), 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyltriazine (melting point 215 to 225 ° C.), 2-phenylimidazole (melting point) 137-147 ° C) and the like.

  The content of the latent epoxy curing agent is preferably 5 parts by weight or more, more preferably 20 parts by weight or more, preferably 60 parts by weight or less, with respect to 100 parts by weight of the total of the epoxy compound and the curable compound. More preferably, it is 50 parts by weight or less. When the content of the latent epoxy curing agent is not less than the above lower limit and not more than the above upper limit, the fast curability of the composition and the moist heat resistance of the cured product are improved in a well-balanced manner.

[Light or thermal radical polymerization initiator]
The light or thermal radical polymerization initiator generates radical species by light irradiation or heating. The light or thermal radical polymerization initiator advances the curing of the curable compound having a radical polymerizable group. The light or thermal radical polymerization initiator is not particularly limited. As the light or thermal radical polymerization initiator, a conventionally known light or thermal radical polymerization initiator can be used. The light or thermal radical polymerization initiator may be a photo radical polymerization initiator or a thermal radical polymerization initiator. As for the said photoradical initiator, only 1 type may be used and 2 or more types may be used together.

  The photo radical polymerization initiator is not particularly limited, and includes acetophenone photo radical polymerization initiator, benzophenone photo radical polymerization initiator, thioxanthone, ketal photo radical polymerization initiator, halogenated ketone, acyl phosphinoxide, and acyl phosphonate. Is mentioned.

  Specific examples of the acetophenone photoradical polymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, Examples include methoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 2-hydroxy-2-cyclohexylacetophenone. Specific examples of the ketal radical photopolymerization initiator include benzyl dimethyl ketal.

  The thermal radical polymerization initiator is not particularly limited, and examples thereof include azo compounds and organic peroxides. Examples of the organic peroxide include diacyl peroxide compounds, peroxy ester compounds, hydroperoxide compounds, peroxydicarbonate compounds, peroxyketal compounds, dialkyl peroxide compounds, and ketone peroxide compounds.

  Examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 1 , 1′-azobis-1-cyclohexanecarbonitrile, dimethyl-2,2′-azobisisobutyrate, dimethyl-2,2′-azobis (2-methylpropionate), dimethyl-1,1′-azobis (1-cyclohexanecarboxylate), 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-amidinopropane) dihydrochloride, 2-tert-butylazo-2-cyanopropane, 2 2,2′-azobis (2-methylpropionamide) dihydrate, 2,2′-azobis (2,4,4-trimethylpentane), and the like.

  Examples of the diacyl peroxide compound include benzoyl peroxide, diisobutyryl peroxide, di (3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, and disuccinic acid peroxide. Examples of the peroxyester compound include cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, tert-hexylperoxyneodecanoate, and tert-butylperoxyneo. Decanoate, tert-butylperoxyneoheptanoate, tert-hexylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2 , 5-di (2-ethylhexanoylperoxy) hexane, tert-hexylperoxy-2-ethylhexanoate, tert-butylperoxypivalate, tert-butylperoxy-2-ethylhexanoate, tert -Butyl peroxyisobutyrate, tert-butyl per Kishiraureto, tert- butylperoxy isophthalate, tert- butylperoxy acetate, tert- butylperoxy octoate and tert- butyl peroxybenzoate, and the like. Examples of the hydroperoxide compound include cumene hydroperoxide and p-menthane hydroperoxide. Examples of the peroxydicarbonate compound include di-sec-butyl peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-n-propyl peroxydicarbonate, diisopropyl peroxycarbonate, and di- (2-ethylhexyl) peroxycarbonate and the like. Other examples of the peroxide include methyl ethyl ketone peroxide, potassium persulfate, and 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane.

  The decomposition temperature for obtaining the 10-hour half-life of the thermal radical polymerization initiator is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, preferably 90 ° C. or lower, more preferably 80 ° C. or lower. When the decomposition temperature for obtaining the 10-hour half-life of the thermal radical polymerization initiator is less than 30 ° C., the storage stability of the curable composition tends to be lowered. It tends to be difficult to sufficiently heat-cure the composition.

  The content of the light or thermal radical polymerization initiator is not particularly limited. The content of the light or thermal radical polymerization initiator with respect to 100 parts by weight of the curable compound is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, preferably 10 parts by weight or less. More preferably, it is 5 parts by weight or less. When the content of the light or thermal radical curing agent is not less than the above lower limit and not more than the above upper limit, the fast curability of the composition and the moist heat resistance of the cured product are improved in a well-balanced manner.

[Compound having two or more thiol groups]
The compound having two or more thiol groups is not particularly limited as long as it has two or more thiol groups. Conventionally known compounds can be used as the compound having two or more thiol groups. As for the compound which has 2 or more of the said thiol groups, only 1 type may be used and 2 or more types may be used together.

  Examples of the compound having two or more thiol groups include mercapto ester compounds, aliphatic polythiols, aromatic polythiols, and thiol-modified reactive silicone oils. Examples of the mercaptoester compound include a reaction product of a mercaptocarboxylic acid and a polyhydric alcohol. You may use compounds other than these.

  The content of the compound having a thiol group with respect to a total of 100 parts by weight of the epoxy compound and the curable compound is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, preferably 5 parts by weight or less, more preferably 3 parts by weight or less. When the content of the compound having a thiol group is not less than the above lower limit and not more than the above upper limit, the fast curability of the composition and the moist heat resistance of the cured product are improved in a well-balanced manner.

[Other ingredients]
The said curable composition may further contain the adhesive force regulator, the flux, the inorganic filler, the solvent, the storage stabilizer, the ion scavenger, the silane coupling agent, etc. as needed.

(Curable composition for electronic parts containing conductive particles)
When the curable composition contains conductive particles, the curable composition can be used as a conductive material. The conductive material is preferably an anisotropic conductive material. The conductive material is preferably used for electrical connection of electrodes. The conductive material is preferably a circuit connection material. The conductive material may not be a liquid crystal sealant composition.

  The conductive particles electrically connect the electrodes of the connection target member. Specifically, the conductive particles electrically connect, for example, electrodes between a circuit board and a semiconductor chip. The conductive particles are not particularly limited as long as they are conductive particles. The said electroconductive particle should just have an electroconductive part on the electroconductive surface.

  Examples of the conductive particles include organic particles, inorganic particles excluding metals, organic / inorganic hybrid particles, or conductive particles whose surfaces are covered with a conductive layer (metal layer), or substantially only metals. Metal particles to be used. The substrate particles inside the conductive layer are preferably substrate particles excluding metal, and more preferably resin particles or organic-inorganic hybrid particles.

  The conductive part is not particularly limited. Gold, silver, copper, nickel, palladium, tin, etc. are mentioned as a metal which comprises the said electroconductive part. Examples of the conductive layer include a gold layer, a silver layer, a copper layer, a nickel layer, a palladium layer, or a conductive 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 is composed of the base material and the conductive material disposed on the surface of the base material particle. It is preferable to have a layer (first conductive layer). From the viewpoint of further improving the conduction reliability between the electrodes, the conductive particles are preferably conductive particles having at least a conductive outer surface of a low melting point metal layer. More preferably, the conductive particles have base particles and a conductive layer disposed on the surface of the base 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 preferably contains tin. In 100% by weight of the metal contained in the low melting point metal, 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 is not less than the lower limit, the connection reliability between the low melting point metal 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 portion 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. Further, the use of conductive particles having at least a conductive outer surface of a low-melting-point metal layer increases the bonding strength between the low-melting-point metal layer and the electrode, resulting in further peeling between the low-melting-point metal layer and the electrode. It becomes difficult to occur, and 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 is preferably solder. Although the material which comprises the said solder is not specifically limited, Based on JISZ3001: welding terminology, it is preferable that it is a filler material whose liquidus is 450 degrees C or less. Examples of the solder composition include metal compositions containing zinc, gold, lead, copper, tin, bismuth, indium and the like. 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 preferably does not contain lead, and is preferably a solder containing tin and indium or a solder containing tin and bismuth.

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

  The conductive particles have base particles and a conductive layer disposed on the surface of the base particles, and the outer surface of the conductive layer is a low melting point metal layer, and the base particles and the above In addition to the low melting point metal layer, a second conductive layer is preferably provided between the low melting point metal layer (such as a solder 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, tungsten, molybdenum and cadmium, and alloys thereof. Is mentioned. 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 average particle diameter of the conductive particles is preferably 100 μm or less, more preferably 20 μm or less, still more preferably less than 20 μm, still more preferably 15 μm or less, particularly preferably 10 μm or less, and most preferably 4 μm or less. The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more. From the viewpoint of further improving the connection reliability of the connection structure when subjected to a thermal history, the average particle diameter of the conductive particles is particularly preferably 1 μm or more and 10 μm or less, and is 1 μm or more and 4 μm or less. Most preferred.

  Since the size is suitable for the conductive particles in the conductive material and the distance between the electrodes can be further reduced, the average particle size of the conductive particles is particularly preferably 1 μm or more and 100 μm or less. .

  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 such as insulating particles, flux, or the like. It is preferable that the insulating material, 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 is suppressed.

  Next, specific examples of conductive particles will be described with reference to FIGS.

  FIG. 4 is a cross-sectional view showing an example of conductive particles.

  The conductive particles shown in FIG. 4 are solder particles 21. The solder particles 21 are formed only by solder. The solder particles 21 do not have base particles in the core and are not core-shell particles. The solder particles 21 are formed of solder at both the central portion and the outer surface.

  FIG. 5 is a cross-sectional view showing a first modification of the conductive particles.

  The conductive particle 31 shown in FIG. 5 includes a base particle 32 and a conductive layer 33 disposed on the surface of the base particle 32. The conductive layer 33 covers the surface of the base particle 32. The conductive particles 31 are coated particles in which the surface of the base particle 32 is coated with the conductive layer 33.

  The conductive layer 33 includes a second conductive layer 33A and a solder layer 33B (first conductive layer) disposed on the surface of the second conductive layer 33A. The conductive particle 31 includes a second conductive layer 33A between the base particle 32 and the solder layer 33B. Accordingly, the conductive particles 31 include the base particle 32, the second conductive layer 33A disposed on the surface of the base particle 32, and the solder layer 33B disposed on the surface of the second conductive layer 33A. Is provided. Thus, the conductive layer 33 may have a multilayer structure or may have a stacked structure of two or more layers.

  As described above, the conductive layer 33 in the conductive particles 31 has a two-layer structure. As in the second modification shown in FIG. 6, the conductive particles 41 may have a solder layer 42 as a single conductive layer. The conductive particles 41 include base material particles 32 and a solder layer 42 disposed on the surface of the base material particles 32.

  All of the conductive particles 21, 31, 41 have solder on the conductive outer surface.

  The content of the conductive particles is not particularly limited. In 100% by weight of the curable composition, the content of the conductive particles 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. Hereinafter, it is more preferably 15% 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 prevented.

(Use of curable composition for electronic parts)
The said curable composition can be used in order to adhere | attach various connection object members.

  When the curable composition is a conductive material containing conductive particles, the conductive material can be used as a conductive paste, a conductive film, or the like. When the conductive material is used as a conductive film, a film not containing conductive particles may be laminated on the conductive film containing conductive particles. The film includes a sheet. The curable composition is preferably a paste-like conductive paste. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

  The said curable composition can be used in order to adhere | attach various connection object members. The said curable composition is a connection structure provided with the 1st connection object member, the 2nd connection object member, and the connection part which has connected the said 1st connection object member and the said 2nd connection object member. It is preferably used to obtain a body. The connection part is formed by curing the curable composition.

  The curable composition for electronic parts includes conductive particles, the first connection target member has a first electrode on the surface, and the second connection target member has a second electrode on the surface. It is preferable to obtain a connection structure in which the first electrode and the second electrode are electrically connected by the conductive particles.

  In FIG. 1, an example of the connection structure using the curable composition which concerns on one Embodiment of this invention is typically shown with sectional drawing.

  The connection structure 1 shown in FIG. 1 is a connection that connects the first connection target member 2, the second connection target member 4, and the first connection target member 2 and the second connection target member 4. Part 3. The connection part 3 is a cured product layer and is formed by curing a curable composition for electronic parts (conductive material) including the conductive particles 5.

  The first connection target member 2 has a plurality of first electrodes 2a on the surface (upper surface). The second connection target member 4 has a plurality of second electrodes 4a on the surface (lower surface). The first electrode 2 a and the second electrode 4 a 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. Instead of the conductive particles 5, conductive particles 21, 31, 41 may be used. It is preferable to use conductive particles having solder on the conductive outer surface, and it is more preferable to use solder particles.

  The connection between the first and second electrodes 2a and 4a is usually performed by connecting the first connection target member 2 and the second connection target member 4 with the first and second electrodes 2a through the curable composition. , 4a are overlapped so as to face each other, and then the curable composition is cured by pressurization. Generally, the conductive particles 5 are compressed by pressurization.

  The said 1st, 2nd connection object member is not specifically limited. Specifically, the first and second connection target members include electronic components such as semiconductor chips, capacitors, and diodes, and circuit boards such as printed boards, flexible printed boards, glass epoxy boards, and glass boards. Examples include parts.

  The electrode width (the width of the region where the electrode is present, the width of the line (L), the first and second electrode widths) is preferably 200 μm or less, more preferably 150 μm or less, still more preferably 100 μm or less, and particularly preferably 80 μm or less. It is. By using conductive particles having solder on the outer surface of the conductive as the conductive particles when the electrode width is small, even in the case of a curable composition that cures quickly, the conductivity and wet heat resistance are effectively improved. Even if it is a curable composition which hardens | cures rapidly by using a solder particle, electrical conductivity and heat-and-moisture resistance can be improved much more effectively.

  The width between the electrodes (the width of the region without electrodes, the width of the space (S), the width between the first and second electrodes) is preferably 200 μm or less, more preferably 150 μm or less, still more preferably 100 μm or less, particularly preferably 80 μm or less. By using conductive particles having solder on the conductive outer surface as the conductive particles when the width between the electrodes is small, even in the case of a curable composition that cures quickly, the insulation reliability is effectively increased. In addition, the use of solder particles can increase the insulation reliability even more effectively even with a curable composition that cures quickly.

  The electrode width / interelectrode width (L / S) is preferably 200 μm or less / 200 μm or less, more preferably 150 μm or less / 150 μm or less, still more preferably 100 μm or less / 100 μm or less, and particularly preferably 80 μm or less / 80 μm or less.

  The connection structure 1 shown in FIG. 1 can be obtained as follows, for example, through the states shown in FIGS.

  As shown in FIG. 2A, a first connection target member 2 having a first electrode 2a on the surface (upper surface) is prepared. Next, a curable composition (conductive material) including a plurality of conductive particles 5 is disposed on the surface of the first connection target member 2, and the curable composition layer is formed on the surface of the first connection target member 2. 3A is formed. At this time, it is preferable that one or a plurality of conductive particles 5 be disposed on the first electrode 2a.

  Next, the curing of the curable composition layer 3A is advanced by irradiating light or applying heat to the curable composition layer 3A. 2A to 2C, the curable composition layer 3 </ b> A is irradiated with light, and the curable composition layer 3 </ b> A is cured to be B-staged. That is, as shown in FIG. 2B, the B-staged curable composition layer 3 </ b> B is formed on the surface of the first connection target member 2. By the B stage, the first connection target member 2 and the B-stage curable composition layer 3B are temporarily bonded. The B-staged curable composition layer 3B is a semi-cured product in a semi-cured state. The B-staged curable composition layer 3B is not completely cured, and thermal curing can further proceed.

In order to effectively advance the curing of the curable composition layer 3A, the light irradiation intensity at the time of irradiation with light is preferably in the range of 0.1 to 8000 mW / cm ² . The integrated light quantity is preferably 0.1 to 20000 J / 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 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, a metal halide lamp, and an LED lamp.

  Next, as shown in FIG.2 (c), the 2nd connection object member 4 is laminated | stacked on the surface opposite to the 1st connection object member 2 side of the curable composition layer 3B made into B stage. To do. The second connection target member 4 is laminated so that the first electrode 2a on the surface of the first connection target member 2 and the second electrode 4a on the surface of the second connection target member 4 face each other.

  Further, when the second connection target member 4 is laminated, the B-staged curable composition layer 3B is further cured by heating the B-staged curable composition layer 3B. 3 is formed. However, the B-staged curable composition layer 3B may be heated before the second connection target member 4 is laminated. Furthermore, you may heat the curable composition layer 3B B-staged after the lamination | stacking of the 2nd connection object member 4. FIG.

  The heating temperature for curing the B-staged curable composition layer 3B is preferably 50 ° C or higher, more preferably 80 ° C or higher, still more preferably 100 ° C or higher, still more preferably 140 ° C or higher, particularly preferably. Is 160 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower.

  It is preferable to apply pressure when the B-staged curable composition layer 3B is cured. By compressing the conductive particles 5 between the first electrode 2a and the second electrode 4a by pressurization, the contact area between the first and second electrodes 2a, 4a and the conductive particles 5 is increased. For this reason, the conduction | electrical_connection reliability between the 1st, 2nd electrodes 2a and 4a becomes high. Further, by compressing the conductive particles 5, even if the distance between the first and second electrodes 2a and 4a increases, the particle diameter of the conductive particles 5 increases so as to follow this expansion.

  By curing the B-staged curable composition layer 3 </ b> B, the first connection target member 2 and the second connection target member 4 are connected via the connection portion 3. In addition, the first electrode 2 a and the second electrode 4 a are electrically connected through the conductive particles 5. In this way, the connection structure 1 shown in FIG. 1 can be obtained. Here, since photocuring and thermosetting are used in combination, the curable composition has the specific composition described above, and therefore the curable composition can be cured in a short time.

  In addition, the said curable composition does not need to contain electroconductive particle. In this case, the curable composition is used to bond and connect the first and second connection target members without electrically connecting the first and second connection target members.

  When the curable composition is a conductive material, the conductive material may be, for example, a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), a connection between a semiconductor chip and a flexible printed circuit board (COF ( (Chip on Film)), connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)), or the like. Especially, the said electrically-conductive material is suitable for a FOG use or a COG use, and is more suitable for a COG use. The curable composition is preferably a conductive material used for connection between the flexible printed circuit board and the glass substrate, or between the semiconductor chip and the flexible printed circuit board, and is used for connection between the semiconductor chip and the flexible printed circuit board. More preferably, it is a conductive material.

  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.

(Synthesis Example 1)
(1) Synthesis of a first reaction product of bisphenol F and 1,6-hexanediol diglycidyl ether:
72 parts by weight of bisphenol F (containing 4,4′-methylene bisphenol, 2,4′-methylene bisphenol and 2,2′-methylene bisphenol at a weight ratio of 31:52:17), 1,6-hexanediol 100 parts by weight of glycidyl ether and 1 part by weight of triphenylphosphine were placed in a three-necked flask and dissolved at 150 ° C. Thereafter, the first reaction product was obtained by addition polymerization at 180 ° C. for 6 hours.

  After confirming that the addition polymerization reaction has progressed, the first reaction product has a structural unit in which the skeleton derived from bisphenol F and the skeleton derived from 1,6-hexanediol diglycidyl ether are bonded to the main chain. And having an epoxy group derived from 1,6-hexanediol diglycidyl ether at both ends was confirmed.

(2) Synthesis of a curable compound obtained by reacting the first reactant with acrylic acid:
100 parts by weight of the obtained first reactant and 4 parts by weight of acrylic acid were blended, and the temperature was raised to 80 ° C. After raising the temperature, 1 part by weight of dimesitylammonium pentafluorobenzenesulfonate, which is a dehydration condensation catalyst of secondary hydroxyl group and carboxyl group, is put into a condensation reaction for 4 hours to have an epoxy group at both ends, and A curable compound 1 (compound represented by the following formula (2)) having 20% vinyl groups in the side chain with respect to 100% of the total number of hydroxyl groups before the reaction was obtained.

  The resulting curable compound 1 had a weight average molecular weight of 8,000. The resulting curable compound 1 had only one peak in the molecular weight distribution, and no low molecular weight derived from acrylic acid was observed. Further, it was confirmed by NMR that acrylic acid reacted with the hydroxyl group, and that 20% of the vinyl group was introduced into the side chain with respect to 100% of the total number of hydroxyl groups before the reaction.

  In the above formula (2), 80% of the total number of R represents an OH group, and 20% of the total number of R represents a group represented by the following formula (a2).

  In addition, the chart of NMR of the compound represented by Formula (2) obtained was shown in FIG. The chemical shift is as follows.

_1.3-1.6ppm: -C _{6 H 12} - internal 6H
2.6-3.0 ppm: H of terminal epoxy group
3.3-3.7 ppm: 5H of —CH ₂ —CHR—CH ₂ —
_3.8-4.0ppm: -C _{6 H 12} - internal 6H
4.1-4.2ppm: _-Ph-CH 2 -Ph- of CH ₂ of 2H
5.8-6.5 ppm: 0.6H with 20% acryloyl group introduced into R
6.7-7.2ppm: 8H of _-Ph-CH 2 -Ph- of Ph

(Synthesis Example 2)
Synthesis of an epoxy compound obtained by reacting the first reactant obtained in Synthesis Example 1 with 2-methacryloyloxyethyl isocyanate:
After blending 100 parts by weight of the first reactant obtained in Synthesis Example 1, 4 parts by weight of 2-methacryloyloxyethyl isocyanate, and 0.3 parts by weight of dibutyltin laurate, the mixture was mixed at 80 ° C. for 4 hours. By addition reaction, a curable compound 2 having an epoxy group at both ends and a vinyl group in the side chain of 20% with respect to 100% of the total number of hydroxyl groups before the reaction was obtained.

  The resulting curable compound 2 had a weight average molecular weight of 12,000. The resulting curable compound 2 had only one peak in the molecular weight distribution, and no low molecular peak derived from the methacrylic acid compound was observed. Further, NMR confirmed that 2-methacryloyloxyethyl isocyanate had reacted with the hydroxyl group, and that 20% of the vinyl group had been introduced into the side chain with respect to 100% of the total number of hydroxyl groups before the reaction.

  Moreover, the following compounding components were prepared.

(Radical polymerizable compound without epoxy group)
Radical polymerizable compound (“A-TMM-3” manufactured by Pentaerythritol Triacrylate)

(Epoxy compound)
Epoxy compound 1 (resorcinol type epoxy compound, “EX-201” manufactured by Nagase ChemteX Corporation)
Epoxy compound 2 (triazine triglycidyl ether, “TEPIC-SS” manufactured by Nissan Chemical Co., Ltd.)

(Latent epoxy curing agent)
Latent epoxy curing agent 1 ("HXA3921HP" manufactured by Asahi Kasei E-Materials)
Latent epoxy curing agent 2 (inclusion imidazole compound, “TIC-188” manufactured by Nippon Soda Co., Ltd.)

(Compound having two or more thiol groups)
Thiol group-containing compound 1 (pentaerythritol tetrakis (3-mercaptobutyrate), “Karenz MT” manufactured by Showa Denko KK)
Thiol group-containing compound 2 (1,3,5-tris (3-mercaptobutyryloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, manufactured by Showa Denko KK “Karenzu MT NR1”)

(Conductive particles)
Conductive particles 1: SnBi solder particles ("Sn58Bi-20" manufactured by Fukuda Metals Co., Ltd., average particle size: 4.5 μm)
Conductive particles 2: (resin core solder coated particles, prepared by the following procedure)
Divinylbenzene resin particles (“Micropearl SP-207” manufactured by Sekisui Chemical Co., Ltd., average particle diameter 7 μm, softening point 330 ° C., 10% K value (23 ° C.) 4 GPa) are electroless nickel-plated on the surface of the resin particles A base nickel plating layer having a thickness of 0.1 μm was formed. 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 1 μm. Thus, a 1 μm thick copper layer is formed on the surface of the resin particles, and a 1 μm thick solder layer (tin: bismuth = 43 wt%: 57 wt%) is formed on the surface of the copper layer. Conductive particles (average particle size 14 μm, CV value 22%, resin core solder-coated particles) were prepared.
Conductive particles 3: Au-plated particles of divinylbenzene resin particles (“Au-210” manufactured by Sekisui Chemical Co., Ltd., average particle size 10 μm)

(Other ingredients)
Photo radical polymerization initiator (acylphosphine oxide compound, “DAROCUR TPO” manufactured by BASF Japan)
Thermal radical polymerization initiator (2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, “Perhexa 250” manufactured by NOF Corporation)
Filler (Nanosilica, “MT-10” manufactured by Tokuyama)
Adhesive agent (Shin-Etsu Chemical Co., Ltd. “KBE-403”)
Flux (“Glutaric acid” manufactured by Wako Pure Chemical Industries, Ltd.)

(Examples 1 to 15 and Comparative Examples 1 and 2)
The components shown in Tables 1 and 2 below were blended in the blending amounts shown in Tables 1 and 2 below, followed by stirring at 2000 rpm for 5 minutes using a planetary stirrer to obtain anisotropic conductive paste.

(Evaluation)
Production of connection structure A (FOB) used in the evaluation items (1) to (3) and (5):
A glass epoxy substrate (FR-4 substrate) having 70 copper electrodes on the upper surface with an electrode pattern having an L / S of 100 μm / 100 μm was prepared. Moreover, the flexible printed circuit board which has 70 copper electrodes on the lower surface with the electrode pattern whose L / S is 100 micrometers / 100 micrometers was prepared. The FR-4 substrate and the flexible printed circuit board pattern were designed so that a daisy chain could be formed by overlapping.

  The obtained anisotropic conductive paste was applied on the upper surface of the glass epoxy substrate so as to have a thickness of 200 μm to form an anisotropic conductive paste layer. Next, UV irradiation was performed for 10 seconds under the condition of 200 mW at a wavelength of 365 nm by an LED-UV irradiator, and the anisotropic conductive paste was made into a B-stage. The flexible printed circuit board was laminated on the B-staged anisotropic conductive paste layer so that the electrodes face each other. Then, while adjusting the temperature of the thermocompression bonding head so that the temperature of the anisotropic conductive paste layer becomes 170 ° C. (final pressure bonding temperature), the pressure bonding head is placed on the upper surface of the flexible printed circuit board and a pressure of 1 MPa is applied. Then, the anisotropic conductive paste layer was cured until curing was completed at 170 ° C. to obtain a connection structure A (FOB).

Production of connection structure B (FOB) used in the evaluation item of (7):
A glass epoxy substrate (FR-4 substrate) having 70 copper electrodes on the upper surface with an electrode pattern having an L / S of 50 μm / 50 μm was prepared. Moreover, the flexible printed circuit board which has 70 copper electrodes on the lower surface with the electrode pattern whose L / S is 50 micrometers / 50 micrometers was prepared. The FR-4 substrate and the flexible printed circuit board pattern were designed so that a daisy chain could be formed by overlapping.

  A connection structure B (FOB) was obtained in the same manner as the connection structure A except that a glass epoxy substrate and a flexible printed circuit board having different L / S were used.

(1) Curing speed When obtaining the said connection structure A, the time until an anisotropic conductive paste layer hardens | cures by heating was measured. The curing rate was determined according to the following criteria.

[Criteria for curing speed]
◯: 80% or more of the connection structure A (FOB) obtained by curing the anisotropic conductive paste layer until the adhesive force at the time of pressure bonding at 170 ° C. for 10 seconds, which is faster than that of Comparative Example 1, is completed. Less than 80% of the connection structure A (FOB) obtained by curing the anisotropic conductive paste layer until the curing is completed, the adhesive force when being bonded at 170 ° C. for 10 seconds, which is slower than Comparative Example 1.

(2) Conductivity 1
Using the obtained connection structure A, 20 connection resistances were evaluated by a four-terminal method. The conductivity was determined according to the following criteria.

[Criteria for conductivity 1]
○○: Average value of connection resistance is 8.0Ω or less ○: Average value of connection resistance exceeds 8.0Ω and 10.0Ω or less △: Average value of connection resistance exceeds 10.0Ω and 15.0Ω or less × Average connection resistance exceeds 15.0Ω

(3) Thermal shock resistance Ten prepared connection structures A were prepared, held at −30 ° C. for 5 minutes, then heated to 80 ° C., held for 5 minutes, and then cooled to −30 ° C. A cooling cycle test was performed in which the process was 1 cycle and 1 hour per cycle. Ten connection structures A were taken out after 500 cycles.

  With respect to 10 connection structures A after 500 cycles of the thermal cycle test, the number of defective conduction between the upper and lower electrodes was counted. Thermal shock resistance was determined according to the following criteria.

[Criteria for thermal shock resistance]
◯: In all 10 connection structures A, the rate of increase in connection resistance from the connection resistance before the thermal cycle test is 5% or less. ○: In all 10 connection structures A, before the thermal cycle test. The increase rate of the connection resistance from the connection resistance is more than 5% and 10% or less. X: Among the 10 connection structures A, the increase rate of the connection resistance from the connection resistance before the thermal cycle test is 10%. There is one or more connection structure A exceeding

(4) Moist heat resistance 1
Wet heat resistance was evaluated by a bias test. Specifically, a glass epoxy substrate (FR-4 substrate) having 70 comb-shaped copper electrode patterns with L / S of 100 μm / 100 μm on the upper surface was prepared. Moreover, the flexible printed circuit board which has 70 comb-shaped copper electrode patterns with L / S of 100 micrometers / 100 micrometers on the lower surface was prepared. A connection structure A ′ was obtained by the same method as the connection structure A used for the evaluation items (1) to (3). The patterns of the FR-4 substrate and the flexible printed circuit board were designed so that a comb pattern could be formed by overlapping. Wet heat resistance was determined according to the following criteria.

[Criteria for wet heat resistance 1]
○○: Resistance value is 10 ⁸ Ω or more ○: Resistance value is 10 ⁷ Ω or more, less than 10 ⁸ Ω ×: Resistance value is less than 10 ⁷ Ω

(5) Evaluation of voids The obtained connection structure A (FOB) was observed, and voids were determined according to the following criteria.

[Void judgment criteria]
○○: 10 or less voids of 50 μm or more among 10 positions between electrodes of the obtained connection structure A (FOB) ○: 100 μm among 10 positions between electrodes of the obtained connection structure A (FOB) The number of the voids is 1 or less. ×: Among the 10 positions between the electrodes of the obtained connection structure A (FOB), the void of 100 μm or more exceeds 1 position.

(6) UV irradiation margin Connections used in the evaluation items (1) to (3) and (5) except that UV irradiation was performed for 20 seconds after 5 seconds under the condition of 200 mW at a wavelength of 365 nm with an LED-UV irradiation machine. The connection structure A ″ (FOB) was obtained in the same manner as the structure A (FOB). Voids were evaluated for the connection structure A ″ irradiated with UV for 5 seconds and 20 seconds.

[Criteria for UV irradiation margin]
Judgment criteria]
○○: Connection structure A ″ (FOB) irradiated with UV for 5 seconds and 20 seconds, and within 10 locations between electrodes, 1 void or less of 50 μm or more ○: Connection irradiated with UV irradiation for 5 seconds and 20 seconds In any one of the structures A ″ (FOB), among the 10 positions between the electrodes, 100 μm or more voids are 1 or less ×: any of the connection structures A ″ (FOB) irradiated with UV for 5 seconds and 20 seconds Of the 10 positions between the electrodes, the void of 100 μm or more exceeds 1 position.

(7) Conductivity 2
Using the obtained connection structure B, the connection resistance at 20 locations was evaluated by the four-terminal method. The conductivity was determined according to the following criteria.

[Criteria for conductivity 2]
○○: Average value of connection resistance is 8.0Ω or less ○: Average value of connection resistance exceeds 8.0Ω and 10.0Ω or less △: Average value of connection resistance exceeds 10.0Ω and 15.0Ω or less × Average connection resistance exceeds 15.0Ω

(8) Moist heat resistance 2
Wet heat resistance was evaluated by a bias test. Specifically, a glass epoxy substrate (FR-4 substrate) having 70 comb-shaped copper electrode patterns with L / S of 50 μm / 50 μm on the upper surface was prepared. Moreover, the flexible printed circuit board which has the 70 comb-shaped copper electrode pattern whose L / S is 50 micrometers / 50 micrometers on the lower surface was prepared. A connection structure B ′ was obtained by the same method as the manufacturing method of the connection structure B used for the evaluation item of (7). The patterns of the FR-4 substrate and the flexible printed circuit board were designed so that a comb pattern could be formed by overlapping. Wet heat resistance was determined according to the following criteria.

[Criteria for wet heat resistance 2]
○○: Resistance value is 10 ⁸ Ω or more ○ 1: Resistance value is 5 × 10 ⁷ Ω or more and less than 10 ⁸ Ω ○ 2: Resistance value is 10 ⁷ Ω or more and less than 5 × 10 ⁷ Ω ×: Resistance value is 10 < ⁷ Ω

  The results are shown in Tables 1 and 2 below.

  In addition, in connection structure A, A 'of Example 1, many conductive particles are arrange | positioned between the electrodes which should be connected rather than connection structure A, A' of Example 6, 7, Example 6 is shown. In the connection structures A and A ′, more conductive particles were arranged between the electrodes to be connected than in the connection structures A and A ′ of Example 7. In the connection structures B and B ′ of the first embodiment, more conductive particles are arranged between the electrodes to be connected than in the connection structures B and B ′ of the sixth and seventh embodiments. In the structures B and B ′, more conductive particles are arranged between the electrodes to be connected than in the connection structures B and B ′ in Example 7. Moreover, although the evaluation results of the continuity 1 of Examples 1, 6, and 7 are all “◯◯”, the connection resistance of the connection structure A of Example 1 is that of the connection structure A of Examples 6 and 7. The connection resistance of the connection structure A in Example 6 was lower than the connection resistance of the connection structure A in Example 7. The evaluation results of the wet heat resistance 1 of Examples 1, 6 and 7 are all “◯◯”, but the resistance value of the connection structure A ′ of Example 1 is the resistance of the connection structure A of Examples 6 and 7. The resistance value of the connection structure A ′ of Example 6 was higher than the resistance value of the connection structure A of Example 7.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... 1st electrode 3 ... Connection part 3A ... Curable composition layer (conductive material layer)
3B ... B-staged curable composition layer (conductive material layer)
DESCRIPTION OF SYMBOLS 4 ... 2nd connection object member 4a ... 2nd electrode 5 ... Conductive particle 21 ... Solder particle 31 ... Conductive particle 32 ... Base particle 33 ... Conductive layer 33A ... 2nd conductive layer 33B ... Solder layer 41 ... Conductive particles 42 ... solder layer

Claims (11)

An epoxy compound having no radically polymerizable group;
A curable compound having an epoxy group and a radically polymerizable group;
A latent epoxy curing agent;
A light or thermal radical polymerization initiator;
A curable composition for electronic parts, comprising a compound having two or more thiol groups.   The curable composition for electronic components according to claim 1, comprising conductive particles.   The curable composition for electronic components according to claim 2, wherein the conductive particles are conductive particles having solder on a conductive outer surface.   The curable composition for electronic components according to claim 3, wherein the conductive particles are solder particles.   The curable composition for electronic components of any one of Claims 2-4 used for the electrical connection of the electrode whose electrode width is 80 micrometers or less.   The curable composition for electronic components according to any one of claims 1 to 5, wherein the curable compound has a weight average molecular weight of 500 or more and 150,000 or less.   The curable composition for electronic components according to any one of claims 1 to 6, wherein the radical polymerizable group of the curable compound is a (meth) acryloyl group.   The electron according to any one of claims 1 to 7, wherein the curable compound is obtained by reacting a reaction product of bisphenol F and 1,6-hexanediol with a compound having a radical polymerizable group. Curable composition for parts. A first connection target member;
A second connection target member;
A connection portion connecting the first connection target member and the second connection target member;
The connection structure in which the said connection part is formed by hardening the curable composition for electronic components of any one of Claims 1-8. The curable composition for electronic parts contains conductive particles,
The first connection object member has a first electrode on the surface,
The second connection object member has a second electrode on the surface,
The connection structure according to claim 9, wherein the first electrode and the second electrode are electrically connected by the conductive particles.   The connection structure according to claim 9 or 10, wherein the first electrode width and the second electrode width are 80 µm or less.

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