KR20180043191A - Conductive material and connection structure - Google Patents

Abstract

A conductive material excellent in transparency of a cured product and hardly discolored due to excellent heat resistance of the cured product is provided. A conductive material according to the present invention is a conductive material that includes a plurality of conductive particles having a solder, a thermosetting compound, and a thermosetting agent on an outer surface portion of a conductive portion, wherein the thermosetting compound has a thermosetting compound having a thiirane group and a triazine skeleton .

Description

Conductive material and connection structure

The present invention relates to a conductive material comprising conductive particles having solder. The present invention also relates to a connection structure using the conductive material.

Anisotropic conductive paste such as anisotropic conductive paste and anisotropic conductive film are widely known. In the anisotropic conductive material, conductive particles are dispersed in the binder.

The anisotropic conductive material can be used for various connection structures, for example, connection (FOG (Film on Glass)) between a flexible printed board and a glass substrate, connection (COF (Chip on Film)) between a semiconductor chip and a flexible printed board, (COG (Chip on Glass)) between a semiconductor chip and a glass substrate, and connection (FOB (Film on Board)) between a flexible printed substrate and a glass epoxy substrate.

For example, when an electrode of a flexible printed substrate and an electrode of a glass epoxy substrate are electrically connected by the anisotropic conductive material, an anisotropic conductive material containing conductive particles is disposed on a glass epoxy substrate. Subsequently, the flexible printed circuit board is laminated and heated and pressed. Thereby, the anisotropic conductive material is cured, and the electrodes are electrically connected through the conductive particles to obtain a connection structure.

As an example of the anisotropic conductive material, Patent Document 1 below discloses an anisotropic conductive material containing conductive particles and a resin component that is not completely cured at the melting point of the conductive particles. Specific examples of the conductive particles include tin (Sn), indium (In), bismuth (Bi), silver (Ag), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd) (Ga), silver (Ag) and thallium (Tl), or alloys of these metals.

Patent Document 1 discloses a resin heating step of heating an anisotropic conductive resin at a temperature higher than the melting point of the conductive particles and not curing the resin component and a resin component curing step of curing the resin component, And the electrodes are electrically connected to each other. In addition, Patent Document 1 describes that mounting is performed by the temperature profile shown in Fig. 8 of Patent Document 1. In Patent Document 1, the conductive particles are melted in the resin component whose curing is not completed at the temperature at which the anisotropic conductive resin is heated.

Patent Document 2 discloses an adhesive tape comprising a resin layer containing a thermosetting resin, solder powder, and a curing agent, wherein the solder powder and the curing agent are present in the resin layer. The adhesive tape is in the form of a film, not a paste.

Japanese Patent Application Laid-Open No. 2004-260131 WO2008 / 023452A1

In a conventional solder powder or an anisotropic conductive paste containing conductive particles having a solder layer on its surface, the transparency of the cured product may be low. Further, the heat resistance of the cured product is low, and the cured product exposed under a high temperature may be discolored.

An object of the present invention is to provide a conductive material which is excellent in transparency of a cured product and excellent in heat resistance of a cured product and therefore is hardly discolored. It is also an object of the present invention to provide a connection structure using the conductive material.

According to a broad aspect of the present invention, a thermosetting compound containing a plurality of conductive particles having solder on an outer surface portion of a conductive portion, a thermosetting compound, and a thermosetting agent, wherein the thermosetting compound has a thiirane group and a triazine skeleton A conductive material is provided.

In a specific aspect of the conductive material according to the present invention, the melting point of the thermosetting compound having a thiadiene group and a triazine skeleton is 140 캜 or higher.

In certain aspects of the conductive material according to the present invention, the conductive material comprises a thermosetting compound different from the thermosetting compound having a thiirane group and a triazine skeleton.

In a specific aspect of the conductive material according to the present invention, the acid value of the conductive particles is 0.1 mg / KOH or more and 10 mg / KOH or less.

In certain aspects of the conductive material according to the present invention, the conductive material comprises a flux.

In a specific aspect of the conductive material according to the present invention, the flux is a flux having an amide group and an aromatic skeleton, or a reactant of an amino group-containing compound having an amide group and having a pKa of 9.5 or less and a carboxylic acid or a carboxylic acid anhydride Flux.

In certain aspects of the conductive material according to the present invention, the flux is solid at 25 占 폚.

In certain aspects of the conductive material according to the present invention, the conductive material comprises a carbodiimide compound.

In a specific aspect of the conductive material according to the present invention, the conductive particles are solder particles.

In a specific aspect of the conductive material according to the present invention, the conductive material includes insulating particles not attached to the surface of the conductive particles.

In a specific aspect of the conductive material according to the present invention, the average particle diameter of the conductive particles is 1 占 퐉 or more and 40 占 퐉 or less.

In a specific aspect of the conductive material according to the present invention, the content of the conductive particles in 100 wt% of the conductive material is 10 wt% or more and 80 wt% or less.

In one specific aspect of the conductive material according to the present invention, the conductive material is a liquid at 25 占 폚 and is a conductive paste.

According to a broad aspect of the present invention, there is provided a display device comprising: a first connection object member having at least one first electrode on its surface; a second connection object member having at least one second electrode on a surface; And a connecting portion connecting the second connection target member, wherein the material of the connecting portion is the above-described conductive material, and the first electrode and the second electrode are electrically connected by the solder portion in the connecting portion Structure is provided.

In a specific aspect of the connection structure according to the present invention, when the mutually opposing portions of the first electrode and the second electrode in the lamination direction of the first electrode, the connection portion, and the second electrode are viewed, And the solder portion in the connection portion is disposed at 50% or more of the area 100% of the portions facing each other of the second electrode.

A conductive material according to the present invention is a conductive material that includes a plurality of conductive particles having a solder, a thermosetting compound, and a thermosetting agent on an outer surface portion of a conductive portion, wherein the thermosetting compound has a thermosetting compound having a thiirane group and a triazine skeleton It is excellent in transparency of the cured product and excellent in heat resistance of the cured product, so that it is difficult to discolor.

1 is a cross-sectional view schematically showing a connection structure obtained by using a conductive material according to an embodiment of the present invention.
2 (a) to 2 (c) are cross-sectional views for explaining each step of an example of a method of manufacturing a connection structure using a conductive material according to an embodiment of the present invention.
3 is a cross-sectional view showing a modification of the connection structure.
4 is a cross-sectional view showing a first example of conductive particles usable in a conductive material.
5 is a cross-sectional view showing a second example of conductive particles usable for a conductive material.
6 is a cross-sectional view showing a third example of conductive particles usable in a conductive material.

Hereinafter, the present invention will be described in detail.

(Conductive material)

The conductive material according to the present invention includes a plurality of conductive particles and a binder. The conductive particle has a conductive portion. The conductive particles have solder on the outer surface portion of the conductive portion. The solder is included in the conductive portion, and is part or all of the conductive portion. The binder is a component other than the conductive particles contained in the conductive material.

The conductive material according to the present invention includes, as the binder, a thermosetting component. The thermosetting component includes a thermosetting compound and a thermosetting agent.

In the conductive material according to the present invention, the thermosetting compound includes a thermosetting compound having a thiirane group and a triazine skeleton.

In the present invention, since the above constitution is provided, the transparency of the cured product can be enhanced, and the heat resistance of the cured product is excellent, so that it is possible to prevent the cured product from being discolored even when exposed to a high temperature.

Further, in the present invention, even if the electrode width is narrow, the solder in the conductive particles can be efficiently arranged on the electrode. When the electrode width is narrow, it tends to be difficult to collect the solder of the conductive particles on the electrode. In the present invention, however, even if the electrode width is narrow, the solder can be sufficiently collected on the electrode. In the present invention, solder in the conductive particles is easily located between the vertically opposed electrodes when the electrodes are electrically connected to each other, and the solder in the conductive particles is electrically connected to the electrode (line) It is possible to efficiently arrange it on the screen. Further, in the present invention, when the electrode width is wide, the solder in the conductive particles is more efficiently arranged on the electrode.

In addition, a part of the solder in the conductive particles is hardly arranged in a region (space) where no electrode is formed, and the amount of solder disposed in the region where no electrode is formed can be significantly reduced. In the present invention, solder not located between opposing electrodes can be efficiently moved between opposing electrodes. Therefore, the conduction reliability between the electrodes can be improved. In addition, it is possible to prevent electrical connection between adjacent electrodes in the lateral direction which should not be connected, and the insulation reliability can be improved.

Further, in the present invention, the heat resistance of the cured product of the conductive material can be increased. Particularly, when a conductive material is used for the optical semiconductor device, heat is generated at the time of light irradiation, and the cured product of the conductive material is exposed at a high temperature. The conductive material according to the present invention is excellent in heat resistance of a cured product and can be suitably used in optical semiconductor devices. In particular, since a thermosetting compound having a thiirane group and a triazine skeleton is used, the heat resistance of the cured product of the conductive material is enhanced.

Further, in the present invention, the refractive index of the cured product of the conductive material can be increased. Particularly, in the present invention, since a thermosetting compound having a thiadiene group and a triazine skeleton is used, the refractive index of the cured product of the conductive material becomes high. From the viewpoint of further increasing the refractive index of the cured product of the conductive material, the thermosetting compound preferably contains a thermosetting compound having a triazine skeleton, more preferably a thermosetting compound having a thiirane group and a triazine skeleton In the present invention, the thermosetting compound includes a thermosetting compound having a thiirane group and a triazine skeleton. The refractive index of the thermosetting compound is preferably 1.75 or more, more preferably 1.8 or more, preferably 1.9 or less, more preferably 1.85 or less. When the refractive index of the thermosetting compound is lower than the lower limit, the refractive index of the cured product of the conductive material can be further increased.

The refractive index of the thermosetting compound can be measured using a Kalman refractometer. For example, KPR-3000 manufactured by Shimadzu Seisakusho Co., Ltd. is used as the above-mentioned Kalnew refractometer.

Further, in the present invention, the water absorption rate of the cured product of the conductive material can be lowered. Particularly, in the present invention, since a thermosetting compound having a thiadiene group and a triazine skeleton is used, the water absorption of the cured product of the conductive material is lowered. From the viewpoint of further lowering the water absorption of the cured product of the conductive material, the thermosetting compound preferably contains a thermosetting compound having a triazine skeleton, more preferably a thermosetting compound having a thiazine group and a triazine skeleton In the present invention, the thermosetting compound includes a thermosetting compound having a thiirane group and a triazine skeleton. The water absorption rate of the thermosetting compound is preferably 2% or less, more preferably 1.5% or less. If the water absorption rate of the thermosetting compound is not more than the upper limit, the water absorption of the cured product of the conductive material can be further lowered. The lower limit of the absorption rate of the thermosetting compound is not particularly limited. The water absorption rate of the thermosetting compound may be 0.1% or more. From the viewpoint of further lowering the water absorption of the cured product of the conductive material, the water absorption rate of the thermosetting compound is preferably low.

The water absorption of the thermosetting compound can be measured in the following manner.

5 g of the thermosetting compound is placed in a water system and the weight is measured after drying at 105 DEG C for 5 hours, whereby the water absorption rate can be calculated. As the moisture meter, for example, "MOC63u" manufactured by Shimadzu Corporation is used.

In addition, in the present invention, it is possible to prevent displacement between electrodes. In the present invention, in a state in which the electrode of the first connection target member and the electrode of the second connection target member are out of alignment when the second connection target member is superposed on the first connection target member having the conductive material arranged on the upper surface, The electrode of the first connection target member and the electrode of the second connection target member can be connected by correcting the shift even when the first connection target member and the second connection target member overlap each other (self-alignment effect).

In order to more effectively arrange the solder on the electrode, the conductive material is preferably liquid at 25 占 폚, and is preferably a conductive paste. In order to more effectively arrange the solder on the electrode, the viscosity (? 25) of the conductive material at 25 占 폚 is preferably 10 Pa · s or more, more preferably 50 Pa · s or more, still more preferably 100 Pa · s Preferably not more than 800 Pa · s, more preferably not more than 600 Pa · s, even more preferably not more than 500 Pa · s. The viscosity (? 25) can be appropriately adjusted depending on the type and blending amount of the compounding ingredients. In addition, by using the filler, the viscosity can be relatively increased.

The viscosity (? 25) can be measured at 25 占 폚 and 5 rpm using, for example, an E-type viscometer ("TVE22L" manufactured by Axis Industries, Inc.).

The conductive material can be used as a conductive paste and a conductive film. The conductive paste is preferably an anisotropic conductive paste, and the conductive film is preferably an anisotropic conductive film. From the standpoint of more efficiently arranging the solder in the conductive particles on the electrode, the conductive material is preferably a conductive paste. The conductive material is suitably used for electrical connection of electrodes. The conductive material is preferably a circuit connecting material.

Hereinafter, each component contained in the conductive material will be described.

(Conductive particles)

The conductive particles electrically connect the electrodes of the member to be connected. The conductive particles have solder on the outer surface portion of the conductive portion. The conductive particles may be solder particles formed by solder. The solder particles have solder on the outer surface portion of the conductive portion. In the solder particles, the center portion and the outer surface portion of the conductive portion are all formed of solder. The solder particles are particles in which both the center portion of the solder particles and the conductive outer surface are solder. The conductive particles may have base particles and conductive parts disposed on the surface of the base particles. In this case, the conductive particles have solder on the outer surface portion of the conductive portion.

Further, in the case of using the conductive particles having the base particles not formed by solder and the solder portions disposed on the surface of the base particles, as compared with the case of using the solder particles, the conductive particles are less likely to gather on the electrode, Since the solder bonding property between the particles is low, the conductive particles moved on the electrode tends to move out of the electrode, and the effect of suppressing the positional displacement between the electrodes tends to be lowered. Therefore, it is preferable that the conductive particles are solder particles formed by solder.

It is preferable that a carboxyl group or an amino group is present on the outer surface (outer surface of the solder) of the conductive particles, and a carboxyl group is present in the outer surface of the conductive particles effectively from the viewpoint of effectively lowering the connection resistance in the connection structure and effectively suppressing the generation of voids It is preferable that an amino group is present. It is preferable that a carboxyl group or a group containing an amino group is covalently bonded to the outer surface (outer surface of the solder) of the conductive particle through a Si-O bond, an ether bond, an ester bond or a group represented by the following formula (X) . The group containing a carboxyl group or an amino group may contain both a carboxyl group and an amino group. In the following formula (X), the right end and the left end indicate binding sites.

There is a hydroxyl group on the surface of the solder. By covalently bonding the hydroxyl group and the group containing a carboxyl group, it is possible to form a stronger bond than in the case of bonding with another coordination bond (chelate coordination) or the like, so that the connection resistance between the electrodes can be lowered and the generation of voids can be suppressed Conductive particles are obtained.

In the conductive particles, a coordination bond may not be contained in the solder surface and a bond form of a group containing a carboxyl group, and a bond due to the chelate coordination may not be included.

From the viewpoint of effectively lowering the connection resistance in the connection structure and effectively suppressing the generation of voids, the conductive particles are preferably a compound having a functional group capable of reacting with a hydroxyl group and a carboxyl group or an amino group (hereinafter sometimes referred to as a compound X) Is preferably obtained by reacting the hydroxyl group of the solder surface with a functional group capable of reacting with the hydroxyl group. In this reaction, a covalent bond is formed. By reacting the hydroxyl group on the surface of the solder with the functional group capable of reacting with the hydroxyl group in the compound X, it is possible to easily obtain conductive particles having a carboxyl group or a group containing an amino group covalently bonded to the surface of the solder, A solder particle in which a carboxyl group or a group containing an amino group is covalently bonded through an ester bond can be obtained. The compound X can be chemically bonded to the solder surface in the form of a covalent bond by reacting the hydroxyl group of the surface of the solder with the functional group capable of reacting with the hydroxyl group.

Examples of the functional group capable of reacting with the hydroxyl group include a hydroxyl group, a carboxyl group, an ester group, and a carbonyl group. A hydroxyl group or a carboxyl group is preferable. The functional group capable of reacting with the hydroxyl group may be a hydroxyl group or a carboxyl group.

Examples of the compound having a functional group capable of reacting with a hydroxyl group include compounds having a functional group reactive with a hydroxyl group such as levulic acid, glutaric acid, glycolic acid, succinic acid, malic acid, oxalic acid, malonic acid, adipic acid, , 3-mercaptopropionic acid, 3-mercaptopropionic acid, 3-phenylpropionic acid, 3-phenylisobutyric acid, 4-phenylbutyric acid, decanoic acid, dodecanoic acid, tetradecanoic acid, pentadecane (9,12,15) -linolenic acid, nonadecanoic acid, arachidic acid, decanedioic acid, dodecanedioic acid and dodecanedioic acid, and mixtures thereof. And Osan. Glutaric acid or glycolic acid is preferred. The compound having a functional group capable of reacting with the hydroxyl group may be used alone, or two or more compounds may be used in combination. The compound having a functional group capable of reacting with the hydroxyl group is preferably a compound having at least one carboxyl group.

The compound X preferably has a flux action, and the compound X preferably has a flux action in a state bonded to the solder surface. The compound having a flux action can remove the oxide film on the solder surface and the oxide film on the electrode surface. The carboxyl group has a flux action.

Examples of the compound having a flux action include levulic acid, glutaric acid, glycolic acid, succinic acid, 5-ketohexanoic acid, 3-hydroxypropionic acid, 4-aminobutyric acid, 3- mercaptopropionic acid, 3- , 3-methylthiopropionic acid, 3-phenylpropionic acid, 3-phenylisobutyric acid, and 4-phenylbutyric acid. Glutaric acid or glycolic acid is preferred. The above-mentioned compounds having a flux action may be used alone, or two or more thereof may be used in combination.

From the viewpoint of effectively lowering the connection resistance in the connection structure and suppressing the generation of voids effectively, it is preferable that the functional group capable of reacting with the hydroxyl group in the compound X is a hydroxyl group or a carboxyl group. The functional group capable of reacting with the hydroxyl group in the compound X may be a hydroxyl group or a carboxyl group. When the functional group capable of reacting with the hydroxyl group is a carboxyl group, the compound X preferably has at least two carboxyl groups. By reacting a part of the carboxyl group of the compound having at least two carboxyl groups with the hydroxyl group on the surface of the solder, conductive particles having a carboxyl group-containing group covalently bonded to the surface of the solder are obtained.

The method for producing the conductive particles includes a step of mixing conductive particles, a compound having a functional group capable of reacting with a hydroxyl group and a carboxyl group, a catalyst and a solvent using conductive particles, for example. In the method for producing conductive particles, conductive particles having a carboxyl group-containing covalent bond on the solder surface can be easily obtained by the mixing step.

In the method for producing the conductive particles, it is preferable to use conductive particles to mix the conductive particles, a compound having a functional group capable of reacting with the hydroxyl group and a carboxyl group, the catalyst and the solvent, and then heating them. By the mixing and heating process, conductive particles having a carboxyl group-containing covalent bond on the solder surface can be obtained more easily.

Examples of the solvent include alcohol solvents such as methanol, ethanol, propanol and butanol, acetone, methyl ethyl ketone, ethyl acetate, toluene and xylene. The solvent is preferably an organic solvent, more preferably toluene. The solvent may be used alone, or two or more solvents may be used in combination.

Examples of the catalyst include p-toluenesulfonic acid, benzenesulfonic acid and 10-camphorsulfonic acid. The catalyst is preferably p-toluenesulfonic acid. The catalyst may be used alone or in combination of two or more.

It is preferable to heat at the time of mixing. The heating temperature is preferably 90 占 폚 or higher, more preferably 100 占 폚 or higher, preferably 130 占 폚 or lower, more preferably 110 占 폚 or lower.

From the viewpoint of effectively lowering the connection resistance in the connection structure and effectively suppressing the generation of voids, it is preferable that the conductive particles are obtained through a step of reacting the isocyanate compound with the hydroxyl group on the surface of the solder using an isocyanate compound Do. In this reaction, a covalent bond is formed. By reacting the hydroxyl group on the surface of the solder with the isocyanate compound, conductive particles having the nitrogen atom of the group derived from the isocyanate group covalently bonded to the surface of the solder can be easily obtained. By reacting the hydroxyl group of the surface of the solder with the isocyanate compound, a group derived from an isocyanate group can be chemically bonded to the surface of the solder in the form of a covalent bond.

In addition, a silane coupling agent can be easily reacted with a group derived from an isocyanate group. The conductive particles can be easily obtained. Therefore, when the group containing a carboxyl group is introduced by a reaction using a silane coupling agent having a carboxyl group, or after a reaction using a silane coupling agent, a carboxyl group is introduced into a group derived from the silane coupling agent It is preferable that the compound is introduced by reacting at least one compound. It is preferable that the conductive particles are obtained by reacting the isocyanate compound with the hydroxyl group on the surface of the solder using the isocyanate compound and then reacting the compound having at least one carboxyl group.

From the viewpoint of effectively lowering the connection resistance in the connection structure and effectively suppressing the generation of voids, it is preferable that the compound having at least one carboxyl group has a plurality of carboxyl groups.

Examples of the isocyanate compound include diphenylmethane-4,4'-diisocyanate (MDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI) and isophorone diisocyanate (IPDI). Other isocyanate compounds may be used. The carboxyl group can be introduced into the surface of the solder through the group represented by the formula (X) by reacting the compound with the solder surface, reacting the remaining isocyanate group with a compound having a carboxyl group and reactivity with the remaining isocyanate group .

As the isocyanate compound, a compound having an unsaturated double bond and having an isocyanate group may be used. For example, 2-acryloyloxyethyl isocyanate and 2-isocyanatoethyl methacrylate. Reacting the isocyanate group of the compound with the surface of the solder and then reacting the compound having a functional group having reactivity with the remaining unsaturated double bond and having a carboxyl group to form a carboxyl group on the surface of the solder through a group represented by the formula Can be introduced.

Examples of the silane coupling agent include 3-isocyanate propyltriethoxysilane (KBE-9007 manufactured by Shin-Etsu Silicone Co., Ltd.) and 3-isocyanatepropyltrimethoxysilane (Y-5187 manufactured by MOMENTIVE). The silane coupling agent may be used either singly or in combination of two or more.

Examples of the compound having at least one carboxyl group include at least one compound selected from the group consisting of levulic acid, glutaric acid, glycolic acid, succinic acid, malic acid, oxalic acid, malonic acid, adipic acid, 5-ketohexanoic acid, 3-hydroxypropionic acid, 3-mercaptopropionic acid, 3-phenylisobutyric acid, 4-phenylbutyric acid, decanoic acid, dodecanoic acid, tetradecanoic acid, pentadecanoic acid, 3-mercaptopropionic acid, 3-mercaptopropionic acid, 3- (9,12,15) -linolenic acid, nonadecanoic acid, arachidic acid, decanedioic acid, and dodecanedioic acid, such as, for example, stearic acid, hexadecanoic acid, 9-hexadecenoic acid, heptadecanoic acid, stearic acid, oleic acid, And the like. Glutaric acid, adipic acid or glycolic acid are preferable. The compound having at least one carboxyl group may be used alone, or two or more compounds may be used in combination.

A group containing a carboxyl group may be left by reacting a hydroxyl group of the surface of the solder with the isocyanate compound using the isocyanate compound and then reacting a part of the carboxyl group of the compound having a plurality of carboxyl groups with the hydroxyl group on the surface of the solder.

In the method for producing the conductive particles, the isocyanate compound is reacted with the hydroxyl group on the surface of the solder using conductive particles or an isocyanate compound, and then the compound having at least one carboxyl group is reacted, A conductive particle to which a group containing a carboxyl group is bonded is obtained through a group represented by the formula (X). In the method for producing the conductive particles, conductive particles into which a group containing a carboxyl group is introduced on the surface of the solder can be easily obtained by the above process.

Specific methods for producing the conductive particles include the following methods. Conductive particles are dispersed in an organic solvent, and a silane coupling agent having an isocyanate group is added. Thereafter, a silane coupling agent is covalently bonded to the surface of the solder by using a reaction catalyst of a hydroxyl group and an isocyanate group on the solder surface of the conductive particles. Subsequently, the hydroxyl group is generated by hydrolyzing the alkoxy group bonded to the silicon atom of the silane coupling agent. A carboxyl group of a compound having at least one carboxyl group is reacted with the produced hydroxyl group.

Specific examples of the method for producing the conductive particles include the following methods. A conductive particle is dispersed in an organic solvent, and a compound having an isocyanate group and an unsaturated double bond is added. Thereafter, a covalent bond is formed by using a reaction catalyst of hydroxyl group and isocyanate group on the solder surface of the conductive particles. Thereafter, a compound having an unsaturated double bond and a carboxyl group is reacted with the introduced unsaturated double bond.

Examples of the reaction catalyst of the hydroxyl group and the isocyanate group on the solder surface of the conductive particles include tin catalysts such as dibutyltin dilaurate, amine catalysts such as triethylenediamine, carboxylate catalysts such as naphthenic acid, ), And trialkylphosphine catalysts (such as triethylphosphine).

From the viewpoint of effectively reducing the connection resistance in the connection structure and effectively suppressing the generation of voids, the compound having at least one carboxyl group is preferably a compound represented by the following formula (1). The compound represented by the following formula (1) has a flux action. Further, the compound represented by the following formula (1) has a flux action in a state of being introduced on the solder surface.

In the above formula (1), X represents a functional group capable of reacting with a hydroxyl group, and R represents a divalent organic group having 1 to 5 carbon atoms. The organic group may contain a carbon atom, a hydrogen atom and an oxygen atom. The organic group may be a divalent hydrocarbon having 1 to 5 carbon atoms. The main chain of the organic group is preferably a divalent hydrocarbon group. In the corresponding organic group, a carboxyl group or a hydroxyl group may be bonded to a bivalent hydrocarbon group. The compound represented by the above formula (1) includes, for example, citric acid.

The compound having at least one carboxyl group is preferably a compound represented by the following formula (1A) or (1B). The compound having at least one carboxyl group is preferably a compound represented by the following formula (1A), more preferably a compound represented by the following formula (1B).

In the above formula (1A), R represents a divalent organic group having 1 to 5 carbon atoms. R in the formula (1A) is the same as R in the formula (1).

In the above formula (1B), R represents a divalent organic group having 1 to 5 carbon atoms. R in the formula (1B) is the same as R in the formula (1).

It is preferable that a group represented by the following formula (2A) or a group represented by the following formula (2B) is bonded to the surface of the solder. It is preferable that a group represented by the following formula (2A) is bonded to the surface of the solder, and it is more preferable that a group represented by the following formula (2B) is bonded. In the following formulas (2A) and (2B), the left end indicates a bonding site.

In the formula (2A), R represents a divalent organic group having 1 to 5 carbon atoms. R in the formula (2A) is the same as R in the formula (1).

In the formula (2B), R represents a divalent organic group having 1 to 5 carbon atoms. R in the formula (2B) is the same as R in the formula (1).

From the viewpoint of enhancing the wettability of the solder surface, the molecular weight of the compound having at least one carboxyl group is preferably 10000 or less, more preferably 1000 or less, still more preferably 500 or less.

The molecular weight means the molecular weight that can be calculated from the structural formula when the compound having at least one carboxyl group is not a polymer and when the structural formula of the compound having at least one carboxyl group can be specified. When the compound having at least one carboxyl group is a polymer, it means a weight average molecular weight.

It is preferable that the conductive particles have a conductive particle body and an anionic polymer disposed on the surface of the conductive particle body in that the cohesiveness of the conductive particles can be effectively increased at the time of conductive connection. The conductive particles are preferably obtained by surface-treating the conductive particle body with an anionic polymer or a compound to be an anionic polymer. The conductive particles are preferably surface-treated with an anionic polymer or a compound to be an anionic polymer. The anionic polymer and the compound to be the anionic polymer may be used alone or in combination of two or more. The anionic polymer is a polymer having an acidic group.

Examples of the method of surface-treating the conductive particle body with the anionic polymer include anionic polymers such as (meth) acrylic polymers obtained by copolymerizing (meth) acrylic acid, polyesters synthesized from dicarboxylic acids and diols and having carboxyl groups at both terminals A polymer obtained by an intermolecular dehydration condensation reaction of a polymer and a dicarboxylic acid and having a carboxyl group at both terminals, a polyester polymer synthesized from a dicarboxylic acid and a diamine and having a carboxyl group at both terminals, and a modified polymer having a carboxyl group And "Gosenel T" manufactured by Nippon Gosei Chemical Industry Co., Ltd.), and the like. The carboxyl group of the anionic polymer is reacted with the hydroxyl group on the surface of the conductive particle body.

Examples of the anion moiety of the anionic polymer include the carboxyl groups described above, and other groups include a tosyl group (pH ₃ CC ₆ H ₄ S (═O) ₂ -), a sulfonic acid ion group (-SO ₃ ^- ), -PO ₄ ^- ).

Another method of surface treatment is to use a compound having a functional group that reacts with the hydroxyl group on the surface of the conductive particle body and further having a functional group capable of being polymerized by an addition or condensation reaction to form the compound on the surface of the conductive particle body Followed by polymerization. Examples of the functional group that reacts with the hydroxyl group on the surface of the conductive particle body include a carboxyl group and an isocyanate group. Examples of the functional group capable of polymerizing by an addition or condensation reaction include a hydroxyl group, a carboxyl group, an amino group and a (meth) acryloyl group .

The weight average molecular weight of the anionic polymer is preferably 2000 or more, more preferably 3000 or more, preferably 10000 or less, more preferably 8000 or less. When the weight average molecular weight is not less than the lower limit and not higher than the upper limit, a sufficient amount of charge and fluxability can be introduced into the surface of the conductive particles. Thereby, the cohesiveness of the conductive particles can be effectively increased at the time of conductive connection, and the oxide film on the surface of the electrode can be effectively removed at the time of connection of the member to be connected.

When the weight average molecular weight is not less than the lower limit and not more than the upper limit, it is easy to dispose the anionic polymer on the surface of the conductive particle body, effectively increase the cohesiveness of the conductive particle at the time of conductive connection, It can be arranged more efficiently.

The weight average molecular weight refers to the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

The weight average molecular weight of the polymer obtained by subjecting the conductive particle body to surface treatment with a compound to be an anionic polymer can be determined by dissolving the solder in the conductive particles and removing the conductive particles with dilute acid or the like which does not cause decomposition of the polymer, And measuring the weight average molecular weight.

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

4 is a cross-sectional view showing a first example of conductive particles usable in a conductive material.

The conductive particles 21 shown in Fig. 4 are solder particles. The conductive particles 21 are entirely formed of solder. The conductive particles 21 do not have the base particles in the core, and are not core shell particles. In the conductive particles 21, both the center portion and the outer surface portion of the conductive portion are formed by solder.

5 is a cross-sectional view showing a second example of conductive particles usable for a conductive material.

The conductive particles 31 shown in Fig. 5 include base particles 32 and conductive portions 33 disposed on the surface of the base particles 32. As shown in Fig. The conductive portion 33 covers the surface of the base particle 32. The conductive particles 31 are coated particles in which the surface of the base particles 32 is covered with the conductive portions 33.

The conductive portion 33 has a second conductive portion 33A and a solder portion 33B (first conductive portion). The conductive particles 31 include a second conductive portion 33A between the base particles 32 and the solder portion 33B. Thus, the conductive particles 31 include the base particles 32, the second conductive portions 33A disposed on the surface of the base particles 32, and the second conductive portions 33A disposed on the outer surfaces of the second conductive portions 33A And a soldering portion 33B.

6 is a cross-sectional view showing a third example of conductive particles usable for a conductive material.

As described above, the conductive portions 33 of the conductive particles 31 have a two-layer structure. The conductive particles 41 shown in Fig. 6 have a solder portion 42 as a single-layer conductive portion. The conductive particles 41 include base particles 32 and a soldering portion 42 disposed on the surface of the base particles 32.

Examples of the base particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles and metal particles. The base particles are preferably base particles other than metal, and are preferably resin particles, inorganic particles other than metal particles, or organic-inorganic hybrid particles. The base particles may be copper particles. The base particles may have a core and a shell disposed on the surface of the core, or may be core shell particles. The core may be an organic core, and the shell may be an inorganic shell.

As the resin for forming the resin particles, various organic materials are suitably used. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; Acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester A resin, a saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, polyetheretherketone, polyether sulfone, divinylbenzene polymer, and divinylbenzene copolymer And the like. Examples of the divinylbenzene-based copolymer and the like include a divinylbenzene-styrene copolymer and a divinylbenzene- (meth) acrylate copolymer. It is preferable that the resin for forming the resin particles is a polymer obtained by polymerizing at least one polymerizable monomer having an ethylenic unsaturated group.

When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenic unsaturated group, examples of the polymerizable monomer having the ethylenic unsaturated group include a non-cross-linkable monomer and a cross-linkable monomer.

Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and? -Methylstyrene; Carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; (Meth) acrylate, ethyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl Alkyl (meth) acrylate compounds such as acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; (Meth) acrylate compounds such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate; Nitrile-containing monomers such as (meth) acrylonitrile; Vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether and propyl vinyl ether; Acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate and vinyl stearate; Unsaturated hydrocarbons such as ethylene, propylene, isoprene and butadiene; Halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride and chlorostyrene.

Examples of the crosslinkable monomer include tetramethylolmethane tetra (meth) acrylate, tetramethylol methane tri (meth) acrylate, tetramethylol methane di (meth) acrylate, trimethylolpropane tri (Meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di Polyfunctional (meth) acrylate compounds such as (meth) acrylate, (poly) propylene glycol di (meth) acrylate, (poly) tetramethylene glycol di (meth) acrylate and 1,4-butanediol di (meth) acrylate; (Meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, trimethylolpropane trimethoxysilane, triallyl trimellitate, divinyl benzene, diallyl phthalate, diallyl acrylamide, diallyl ether, , Silane-containing monomers such as vinyltrimethoxysilane, and the like.

The term " (meth) acrylate " refers to acrylate and methacrylate. The term " (meth) acryl " refers to acrylic and methacrylic. The term " (meth) acryloyl " refers to acryloyl and methacryloyl.

The above-mentioned resin particles can be obtained by polymerizing the above-mentioned polymerizable monomer having an ethylenic unsaturated group by a known method. Examples of the method include suspension polymerization in the presence of, for example, a radical polymerization initiator, and polymerization by swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

When the base particles are inorganic particles other than metals or organic-inorganic hybrid particles, examples of inorganic substances for forming base particles include silica, alumina, barium titanate, zirconia and carbon black. It is preferable that the inorganic substance is not a metal. The particles formed by the silica are not particularly limited. For example, particles obtained by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, followed by calcination if necessary have. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell disposed on the surface of the core. The core is preferably an organic core. Preferably, the shell is an inorganic shell. From the viewpoint of effectively lowering the connection resistance between the electrodes, the base particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell disposed on the surface of the organic core.

As the material for forming the organic core, a resin for forming the above-mentioned resin particles can be mentioned.

Examples of the material for forming the inorganic shell include inorganic materials for forming the base particles described above. The material for forming the inorganic shell is preferably silica. It is preferable that the inorganic shell is formed on the surface of the core by making the metal alkoxide into a shell shape by a sol-gel method and then sintering the shell shape. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed by silane alkoxide.

The particle diameter of the core is preferably 0.5 占 퐉 or more, more preferably 1 占 퐉 or more, preferably 100 占 퐉 or less, more preferably 50 占 퐉 or less, further preferably 40 占 퐉 or less, 30 mu m or less, and most preferably 15 mu m or less. When the particle diameter of the core is not less than the lower limit and not more than the upper limit, electroconductive particles more suitable for electrical connection between the electrodes are obtained, and the base particles can be suitably used for the electroconductive particles. For example, when the particle diameter of the core is above the lower limit and below the upper limit, when the electrodes are connected using the conductive particles, the contact area between the conductive particles and the electrode becomes sufficiently large, When the conductive part is formed, it is difficult to form the agglomerated conductive particles. Further, the distance between the electrodes connected via the conductive particles is not excessively large, and the conductive portion is difficult to peel off from the surface of the base particle.

The particle diameter of the core means a diameter when the core has a sphericity, and the maximum diameter when the core has a shape other than sphericity. The particle diameter of the core means the average particle diameter of the core measured by an arbitrary particle diameter measuring apparatus. For example, a particle size distribution measuring device using principles such as laser light scattering, electrical resistance value change, image analysis after image pick-up, etc. can be used.

The thickness of the shell is preferably 100 nm or more, more preferably 200 nm or more, preferably 5 占 퐉 or less, and more preferably 3 占 퐉 or less. When the thickness of the shell is not less than the lower limit and not more than the upper limit, conductive particles more suitable for electrical connection between the electrodes are obtained, and base particles can be used suitably for the conductive particles. The thickness of the shell is an average thickness per base particle. By controlling the sol-gel method, the thickness of the shell can be controlled.

In the case where the base particles are metal particles, silver, copper, nickel, silicon, gold, titanium and the like can be given as metals for forming the metal particles. When the base particles are metal particles, the metal particles are preferably copper particles. However, it is preferable that the base particles are not metal particles.

The particle diameter of the base particles is preferably 0.1 占 퐉 or more, more preferably 1 占 퐉 or more, further preferably 1.5 占 퐉 or more, particularly preferably 2 占 퐉 or more, preferably 100 占 퐉 or less, Is preferably 50 占 퐉 or less, still more preferably 40 占 퐉 or less, further preferably 20 占 퐉 or less, still more preferably 10 占 퐉 or less, particularly preferably 5 占 퐉 or less and most preferably 3 占 퐉 or less. When the particle diameter of the base particles is not lower than the lower limit described above, the contact area between the conductive particles and the electrode becomes larger, so that the reliability of the connection between the electrodes can be further enhanced and the connection resistance between the electrodes connected via the conductive particles can be further lowered . When the particle diameter of the base particles is not more than the upper limit, the conductive particles are easily compressed sufficiently, the connection resistance between the electrodes can be further lowered, and the interval between the electrodes can be made smaller.

The particle diameter of the base particles shows a diameter when base particles are spherical, and shows a maximum diameter when base particles are not spherical.

Particle diameter of the base particles is particularly preferably 2 탆 or more and 5 탆 or less. If the particle size of the base particles is within the range of 2 占 퐉 or more and 5 占 퐉 or less, the distance between the electrodes can be further reduced, and even if the thickness of the conductive layer is increased, small conductive particles can be obtained.

A method of forming a conductive portion on the surface of the base particle and a method of forming a solder portion on the surface of the base particle or on the surface of the second conductive portion are not particularly limited. Examples of the method for forming the conductive portion and the solder portion include a method by electroless plating, a method by electroplating, a method by physical impact, a method by mechanochemical reaction, a method by physical vapor deposition or physical adsorption And a method of coating the surface of the base particles with a paste containing a metal powder or a metal powder and a binder. Electroless plating, electroplating or physical impacts are suitable. Examples of the physical deposition method include vacuum deposition, ion plating and ion sputtering. Further, in the above-mentioned physical collision method, for example, Seta Composer (manufactured by Tokushu Kogaku Co., Ltd.) is used.

The melting point of the base particles is preferably higher than the melting point of the conductive portion and the soldering portion. The melting point of the base particles preferably exceeds 160 캜, more preferably exceeds 300 캜, more preferably exceeds 400 캜, and particularly preferably exceeds 450 캜. The melting point of the base particles may be less than 400 占 폚. The melting point of the base particles may be 160 캜 or less. The base particles preferably have a softening point of 260 캜 or higher. The softening point of the base particles may be less than 260 캜.

The conductive particles may have a single-layered solder portion. The conductive particles may have a plurality of conductive portions (solder portions, second conductive portions). That is, in the conductive particles, two or more conductive portions may be laminated. When the conductive portion is two or more layers, it is preferable that the conductive particles have solder on the outer surface portion of the conductive portion.

The solder is preferably a metal having a melting point of 450 캜 or less (low melting point metal). The solder portion is preferably a metal layer (low-melting-point metal layer) having a melting point of 450 DEG C or lower. The low melting point metal layer is a layer containing a low melting point metal. The solder in the conductive particle is preferably a metal particle (low melting point metal particle) having a melting point of 450 캜 or lower. The low melting point metal particles are particles containing a low melting point metal. The low melting point metal means a metal having a melting point of 450 캜 or lower. The melting point of the low melting point metal is preferably 300 DEG C or lower, more preferably 160 DEG C or lower. It is preferable that the solder in the conductive particle includes tin. The content of tin among the 100 wt% of the metal contained in the soldering portion and the 100 wt% of the metal contained in the solder in the conductive particles is preferably 30 wt% or more, more preferably 40 wt% Preferably not less than 70% by weight, particularly preferably not less than 90% by weight. When the content of tin contained in the solder in the conductive particles is not lower than the lower limit described above, the conductivity reliability of the conductive particles and the electrode is further enhanced.

The content of the tin was determined by using a high frequency inductively coupled plasma emission spectrochemical analyzer ("ICP-AES" manufactured by Horiba Seisakusho Co., Ltd.) or a fluorescent X-ray analyzer ("EDX-800HS" available from Shimadzu Corporation) .

By using the conductive particles having the solder on the outer surface portion of the conductive portion, the solder is melted and bonded to the electrode, and the solder conducts the electrodes. For example, if the solder and the electrode are not in point contact, they are likely to come into contact, so that the connection resistance is lowered. The use of the conductive particles having the solder on the outer surface portion of the conductive portion increases the bonding strength between the solder and the electrode. As a result, the solder and the electrode are less likely to be peeled off, and the reliability of conduction is effectively increased.

The soldering portion and the low melting point metal constituting the solder particle are not particularly limited. The low melting point metal is preferably an alloy containing tin or tin. Examples of the alloy include tin-silver alloy, tin-copper alloy, tin-silver-copper alloy, tin-bismuth alloy, tin-zinc alloy and tin-indium alloy. The low melting point metal is preferably tin, a tin-silver alloy, a tin-silver-copper alloy, a tin-bismuth alloy, and a tin-indium alloy from the viewpoint of excellent wettability to the electrode. Tin-bismuth alloy, and tin-indium alloy.

The material constituting the solder (soldering portion) is preferably a filler material having a liquidus temperature of 450 DEG C or less based on JIS Z3001: welding terminology. Examples of the composition of the solder include a metal composition including zinc, gold, silver, lead, copper, tin, bismuth, indium and the like. Tin-indium based (117 占 폚 eutectic) or tin-bismuth (139 占 폚) low melting point and lead-free are 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 solder and the electrode, the solder in the conductive particle is preferably selected from the group consisting of nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, , Chromium, molybdenum, palladium, and the like. From the viewpoint of further increasing the bonding strength between the solder and the electrode, it is preferable that the solder in the conductive particle includes nickel, copper, antimony, aluminum or zinc. From the viewpoint of further increasing the bonding strength between the solder and the electrode in the solder portion or the conductive particles, the content of these metals for increasing the bonding strength is preferably 0.0001 wt% Or more, preferably 1 wt% or less.

The melting point of the second conductive portion is preferably higher than the melting point of the soldering portion. The melting point of the second conductive portion is preferably more than 160 ° C, more preferably more than 300 ° C, more preferably more than 400 ° C, even more preferably more than 450 ° C, Gt; 500 C, < / RTI > and most preferably greater than 600 C. < / RTI > Since the solder portion has a low melting point, it is melted at the time of conductive connection. It is preferable that the second conductive portion is not melted at the time of conductive connection. It is preferable that the conductive particles are used by melting the solder. It is preferable that the conductive particles are used by melting the solder portion, and it is preferable that the conductive particles are used without melting the solder portion and melting the second conductive portion. Since the melting point of the second conductive portion is higher than the melting point of the soldering portion, only the soldering portion can be melted without melting the second conductive portion at the time of conductive connection.

The maximum value of the difference between the melting point of the soldering portion and the melting point of the second conductive portion is preferably more than 0 ° C, preferably 5 ° C or more, more preferably 10 ° C or more, still more preferably 30 ° C or more, Lt; RTI ID = 0.0 > 50 C, < / RTI >

The second conductive portion preferably includes a metal. The metal constituting the second conductive portion is not particularly limited. As the metal, for example, gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, . As the metal, tin-doped indium oxide (ITO) may be used. The metal may be used alone or in combination of two or more.

The second conductive portion 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 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 a nickel layer or a gold layer, and more preferably a copper layer. By using the conductive particles having these preferable conductive portions for connection between the electrodes, the connection resistance between the electrodes is further lowered. In addition, solder portions can be formed more easily on the surfaces of these preferable conductive portions.

The thickness of the soldering portion is preferably 0.005 占 퐉 or more, more preferably 0.01 占 퐉 or more, preferably 10 占 퐉 or less, more preferably 1 占 퐉 or less, further preferably 0.3 占 퐉 or less. When the thickness of the soldering portion is not less than the lower limit and not more than the upper limit, sufficient conductivity is obtained, and the conductive particles are not excessively hardened, and the conductive particles are sufficiently deformed when the electrodes are connected.

The average particle diameter of the conductive particles is preferably 0.5 占 퐉 or more, more preferably 1 占 퐉 or more, further preferably 3 占 퐉 or more, preferably 100 占 퐉 or less, more preferably 50 占 퐉 or less Or less, and particularly preferably 30 mu m or less. It is possible to more effectively arrange the solder in the conductive particles on the electrode and to arrange more solder in the conductive particles between the electrodes when the conductive particles are not less than the lower limit and the upper limit, .

The " average particle diameter " of the conductive particles indicates the number average particle diameter. The average particle diameter of the conductive particles can be obtained, for example, by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating an average value.

The coefficient of variation of the particle diameter of the conductive particles is preferably 5% or more, more preferably 10% or more, preferably 40% or less, and more preferably 30% or less. When the coefficient of variation of the particle diameter is not less than the lower limit and not more than the upper limit, solder in the conductive particles can be more efficiently arranged on the electrode. However, the coefficient of variation of the particle diameter of the conductive particles may be less than 5%.

The coefficient of variation (CV value) is expressed by the following equation.

CV value (%) = (rho / Dn) x100

ρ: standard deviation of the particle diameter of the conductive particles

Dn: Average value of particle diameter of conductive particles

The shape of the conductive particles is not particularly limited. The shape of the conductive particles may be a spherical shape or a shape other than a spherical shape such as a flat shape.

The acid value of the conductive particles is preferably 0.1 mg / KOH or more, more preferably 1 mg / KOH or more, preferably 10 mg / KOH or less, more preferably 7 mg / KOH or less. If the acid value is higher than or equal to the lower limit and lower than or equal to the upper limit, the heat resistance of the cured product is further increased, and the discoloration of the cured product is further suppressed.

The acid value can be measured in the following manner. Phenolphthalein was added to ethanol, and 50 ml of the solution neutralized with 0.1 N-KOH was added with 1 g of conductive particles and dispersed by ultrasonic treatment, followed by titration with 0.1 N-KOH.

The content of the conductive particles in 100 wt% of the conductive material is preferably 1 wt% or more, more preferably 2 wt% or more, still more preferably 10 wt% or more, particularly preferably 20 wt% Preferably 30% by weight or more, preferably 80% by weight or less, more preferably 60% by weight or less, further preferably 50% by weight or less. When the content of the conductive particles is not less than the lower limit and not more than the upper limit, it is possible to more effectively arrange the solder in the conductive particles on the electrode, to easily arrange a large amount of solder in the conductive particles between the electrodes, The conduction reliability is further increased. From the viewpoint of further enhancing conduction reliability, the content of the conductive particles is preferably large.

(Thermosetting compound)

The thermosetting compound is a compound that can be cured by heating. Examples of the thermosetting compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds and polyimide compounds. An epoxy compound or an episulfide compound is preferable from the viewpoint of further improving the curability and viscosity of the conductive material and further improving the connection reliability. The thermosetting compound may be used alone or in combination of two or more.

In the present invention, the thermosetting compound includes a thermosetting compound having a thiirane group and a triazine skeleton. By using such a specific thermosetting property, the transparency of the cured product is enhanced, and the heat resistance of the cured product is enhanced. In addition, since the thermosetting compound has a triazine skeleton, the dielectric constant of the cured product is effectively lowered.

Examples of the thermosetting compound having a triazine skeleton include triazine triglycidyl ether and the like, and TEPIC series (TEPIC-G, TEPIC-S, TEPIC-SS, TEPIC-HP, TEPIC- -PAS, TEPIC-VL, TEPIC-UC). The thermosetting compound having a thiirane group and a triazine skeleton can be obtained, for example, by converting the epoxy group of the thermosetting compound having the triazine skeleton into a thiadiene group. A method of converting an epoxy group into a thiadiene group is known.

The melting point of the thermosetting compound having a thiadiene group and a triazine skeleton is preferably 140 占 폚 or higher, and more preferably 150 占 폚 or higher. When the melting point is the lower limit or higher, the conductive particles are more efficiently arranged between the electrodes. The melting point of the thermosetting compound having a thiirane group and a triazine skeleton is preferably not less than the melting point of the solder in the conductive particle.

The thermosetting compound may contain a thermosetting compound different from the thermosetting compound having a thiirane group and a triazine skeleton. The thermosetting compound other than the thermosetting compound having the thiirane group and the triazine skeleton may be a thermosetting compound having no thiamine group, a thermosetting compound having no triazine skeleton, or an epoxy compound.

Examples of the epoxy compound include aromatic epoxy compounds. A crystalline epoxy compound such as a resorcinol-type epoxy compound, a naphthalene-type epoxy compound, a biphenyl-type epoxy compound, and a benzophenone-type epoxy compound is preferable. An epoxy compound which is solid at normal temperature (23 DEG C) and whose melting temperature is not higher than the melting point of the solder is preferable. The melting temperature is preferably 100 占 폚 or lower, more preferably 80 占 폚 or lower, and preferably 40 占 폚 or higher. By using the above-mentioned preferable epoxy compound, in the step of joining the members to be connected, when the viscosity is high and acceleration is imparted by impact such as transportation, displacement of the first connection object member and the second connection object member is suppressed In addition, the viscosity of the conductive material can be greatly lowered by the heat at the time of curing, and the agglomeration of the solder can be promoted efficiently.

The total content of the thermosetting compound in 100 wt% of the conductive material is preferably 20 wt% or more, more preferably 40 wt% or more, further preferably 50 wt% or more, and preferably 99 wt% or less , More preferably not more than 98 wt%, further preferably not more than 90 wt%, particularly preferably not more than 80 wt%. When the content of the thermosetting compound is lower than or equal to the lower limit and lower than or equal to the upper limit, the solder in the conductive particles is more efficiently arranged on the electrode, the positional displacement between the electrodes is further suppressed, . From the viewpoint of further improving the impact resistance, the content of the above-mentioned thermosetting compound is preferably large.

The content of the thermosetting compound having a thiirane group and a triazine skeleton in 100 wt% of the conductive material is preferably 10 wt% or more, more preferably 20 wt% or more, and preferably 90 wt% And more preferably 80% by weight or less. When the content of the thermosetting compound having a thiirane group and a triazine skeleton is not less than the lower limit and not more than the upper limit, the transparency and heat resistance of the cured product are effectively increased.

(Thermosetting agent)

The thermosetting agent thermally cures the thermosetting compound. Examples of the heat curing agent include an imidazole curing agent, a phenol curing agent, a thiol curing agent, an amine curing agent, an acid anhydride curing agent, a thermal cationic initiator (thermal cationic curing agent), and a thermal radical generator. The thermosetting agent may be used alone or in combination of two or more.

From the viewpoint of enabling the conductive material to be cured more rapidly at a low temperature, it is preferable that the heat curing agent is an imidazole curing agent, a thiol curing agent, or an amine curing agent. From the viewpoint of enhancing the storage stability when the thermosetting compound and the thermosetting agent are mixed, it is preferable that the thermosetting agent is a latent curing agent. The latent curing agent is preferably a latent imidazole curing agent, a latent thiol curing agent or a latent amine curing agent. The thermosetting agent may be coated with a polymer material such as a polyurethane resin or a polyester resin.

The imidazole curing agent is not particularly limited, and examples thereof include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl- Phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')] - ethyl-s-triazine and 2,4- diamino-6- [2 '-Methylimidazolyl- (1')] - ethyl-s-triazine isocyanuric acid adduct.

The thiol curing agent is not particularly limited, and trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate and dipentaerythritol hexa-3-mercaptopropionate And the like.

The solubility parameter of the thiol curing agent is preferably 9.5 or more, and preferably 12 or less. The solubility parameter is calculated by the Fedors method. For example, the solubility parameter of trimethylolpropane tris-3-mercaptopropionate is 9.6 and the solubility parameter of dipentaerythritol hexa-3-mercaptopropionate is 11.4.

The amine curing agent is not particularly limited and includes hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetaspiro [5.5] undecane, bis (4-aminocyclohexyl) methane, metaphenylenediamine, and diaminodiphenylsulfone.

Examples of the thermal cationic initiator (thermal cationic curing agent) include an iodonium-based cationic curing agent, an oxonium-based cationic curing agent, and a sulfonium-based cationic curing agent. Examples of the iodonium-based cationic curing agent include bis (4-tert-butylphenyl) iodonium hexafluorophosphate and the like. Examples of the oxonium-based cation curing agent include trimethyloxonium tetrafluoroborate and the like. Examples of the sulfonium cation-based curing agent include tri-p-tolylsulfonium hexafluorophosphate and the like.

The heat radical generator is not particularly limited, and examples thereof include an azo compound and an organic peroxide. Examples of the azo compound include azobisisobutyronitrile (AIBN) and the like. Examples of the organic peroxide include di-tert-butyl peroxide and methyl ethyl ketone peroxide.

The reaction initiation temperature of the thermosetting agent is preferably 50 占 폚 or higher, more preferably 70 占 폚 or higher, further preferably 80 占 폚 or higher, preferably 250 占 폚 or lower, more preferably 200 占 폚 or lower 150 DEG C or less, particularly preferably 140 DEG C or less. If the reaction initiation temperature of the thermosetting agent is lower than or equal to the lower limit and below the upper limit, the solder is more efficiently disposed on the electrode. The reaction initiation temperature of the thermosetting agent is particularly preferably 80 deg. C or more and 140 deg. C or less.

From the viewpoint of more efficiently placing the solder on the electrode, the reaction initiation temperature of the heat curing agent is preferably higher than the melting point of the solder in the conductive particle, more preferably 5 deg. C or higher, Or more.

The reaction initiation temperature of the heat curing agent means the temperature at which the exothermic peak in DSC starts rising.

The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, and preferably 200 parts by weight or less, more preferably 100 parts by weight or less, based on 100 parts by weight of the total amount of the thermosetting compound Or less, more preferably 75 parts by weight or less. When the content of the heat curing agent is lower than the lower limit, it is easy to sufficiently cure the conductive material. If the content of the thermosetting agent is less than the upper limit, an excess of the thermosetting agent that is not involved in curing after curing is hardly left, and the heat resistance of the cured product is further increased.

(Flux)

It is preferable that the conductive paste includes a flux. By using the flux, the solder can be arranged more effectively on the electrode. The flux is not particularly limited. As the flux, a flux generally used for joining solder or the like can be used.

Examples of the flux include zinc chloride, a mixture of zinc chloride and an inorganic halide, a mixture of zinc chloride and an inorganic acid, a molten salt, a phosphoric acid, a derivative of phosphoric acid, an organic halide, a hydrazine, an organic acid, The flux may be used alone, or two or more fluxes may be used in combination.

Examples of the molten salt include ammonium chloride and the like. Examples of the organic acid include lactic acid, citric acid, stearic acid, glutamic acid and glutaric acid. Examples of the papermaking papers include activated papermaking and inactive papermaking. It is preferable that the flux is an organic acid having two or more carboxyl groups, and a feedstock. The flux may be an organic acid having two or more carboxyl groups, or may be fed. By using an organic acid having two or more carboxyl groups and a papermaking paper, the reliability of conduction between the electrodes is further enhanced.

The above paper is a rosin mainly containing abietic acid. The flux is preferably rosin, more preferably abietic acid. By using this preferable flux, the reliability of conduction between the electrodes is further enhanced.

It is preferable that the flux is a flux having an amide group and an aromatic skeleton or a flux which is a reactant of an amino group-containing compound having an amide group and having a pKa of 9.5 or less with a carboxylic acid or a carboxylic acid anhydride. In this case, the storage stability of the conductive material is enhanced, and the components other than the conductive particles are less likely to flow excessively at the time of connection between the electrodes, thereby increasing the adhesive strength and increasing the reliability of conduction.

The flux is preferably a flux having an amide group and an aromatic skeleton. It is also preferably a flux that has an amide group and is a reaction product of a carboxylic acid or a carboxylic acid anhydride with an amino group-containing compound having a pKa of 9.5 or less. The flux may be used alone, or two or more fluxes may be used in combination.

When the flux is a reaction product of a carboxylic acid or a carboxylic acid anhydride with an amino group-containing compound having a pKa of 9.5 or less, the range of reactants using an amino group-containing compound having a pKa in a specific range may be varied depending on structure or characteristics It is impossible to directly specify.

From the viewpoints of effectively increasing the storage stability of the conductive material and making it more difficult for the components other than the conductive particles to flow at the time of connection between the electrodes, the flux is preferably solid at 25 占 폚.

The flux can be obtained, for example, by reacting a carboxylic acid or a carboxylic anhydride with an amino group-containing compound.

Examples of the carboxylic acid or carboxylic acid anhydride include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and malic acid.

Examples of the amino group-containing compound include benzylamine, aniline, and diphenylamine. The amino group-containing compound is preferably an aromatic amine compound from the viewpoints of effectively increasing the storage stability of the conductive material and making it more difficult for the components other than the conductive particles to flow at the time of connection between the electrodes.

The active temperature (melting point) of the flux is preferably 50 ° C or more, more preferably 70 ° C or more, further preferably 80 ° C or more, preferably 200 ° C or less, more preferably 190 ° C or less, More preferably 160 ° C or lower, even more preferably 150 ° C or lower, still more preferably 140 ° C or lower. When the activation temperature of the flux is higher than or equal to the lower limit and lower than or equal to the upper limit, the flux effect is more effectively exerted and the solder is more efficiently disposed on the electrode. The active temperature (melting point) of the flux is preferably 80 ° C or more and 190 ° C or less. It is particularly preferable that the activation temperature (melting point) of the flux is 80 ° C or more and 140 ° C or less.

(Melting point: 186 占 폚), glutaric acid (melting point: 96 占 폚), adipic acid (melting point: 152 占 폚), pimelic acid (melting point: 104 占 폚), and the like, (Melting point: 122 占 폚), malic acid (melting point: 130 占 폚), and the like.

The boiling point of the flux is preferably 200 ° C or lower.

From the viewpoint of more efficiently placing the solder on the electrode, the melting point of the flux is preferably higher than the melting point of the solder in the conductive particle, more preferably 5 ° C or more, and more preferably 10 ° C or more More preferable.

From the viewpoint of more efficiently placing the solder on the electrode, the melting point of the flux is preferably higher than the reaction initiation temperature of the thermosetting agent, more preferably 5 ° C or higher, further preferably 10 ° C or higher do.

The flux may be dispersed in the conductive material or attached on the surface of the conductive particle.

When the melting point of the flux is higher than the melting point of the solder, the solder can be agglomerated efficiently on the electrode portion. This is because, when heat is applied at the time of bonding, when the electrode formed on the member to be connected and the portion of the member to be connected in the vicinity of the electrode are compared, the thermal conductivity of the electrode portion is higher than the thermal conductivity of the member to be connected to the periphery of the electrode, The temperature rise of the part is caused by the fast. In the step of exceeding the melting point of the solder in the conductive particle, the solder in the conductive particle dissolves but the oxide film formed on the surface does not reach the melting point (active temperature) of the flux and is not removed. In this state, in order for the temperature of the electrode portion to reach the melting point (active temperature) of the flux first, the oxide film on the surface of the solder in the conductive particles that have reached the electrode on the priority is removed first, The charge on the surface of the solder in the conductive particles is neutralized, so that the solder can diffuse on the surface of the electrode. As a result, the solder can be effectively agglomerated on the electrode.

The content of the flux in 100 wt% of the conductive material is preferably 0.5 wt% or more, preferably 30 wt% or less, more preferably 25 wt% or less. The conductive material may not contain a flux. If the content of the flux is lower than or equal to the lower limit and lower than or equal to the upper limit, it is difficult to further form an oxide film on the surface of the solder and the electrode, and furthermore, the oxide film formed on the surface of the solder and the electrode can be removed more effectively.

(Insulating particles)

From the viewpoint of controlling the distance between the connection target members connected by the cured product of the conductive material and the distance between the connection target members connected by the solder in the conductive particles with high accuracy, it is preferable that the conductive material includes insulating particles desirable. In the conductive material, the insulating particles may not be attached to the surface of the conductive particles. In the conductive material, it is preferable that the insulating particles are spaced apart from the conductive particles.

The average particle diameter of the insulating particles is preferably 10 占 퐉 or more, more preferably 20 占 퐉 or more, further preferably 25 占 퐉 or more, preferably 100 占 퐉 or less, more preferably 75 占 퐉 or less Or less. The distance between the connection target members connected by the cured product of the conductive material and the distance between the connection target members connected by the solder in the conductive particles is not more than the lower limit and the upper limit, It becomes more suitable.

Examples of the material of the insulating particles include an insulating resin and an insulating inorganic material. Examples of the insulating resin include the resins listed as resins for forming resin particles that can be used as base particles. Examples of the insulating inorganic material include the inorganic materials listed as inorganic materials for forming the inorganic particles usable as the base particles.

Specific examples of the insulating resin that is the material of the insulating particles include polyolefins, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, thermosetting resins and water- .

Examples of the polyolefins include polyethylene, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid ester copolymer. Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polyethyl (meth) acrylate, and polybutyl (meth) acrylate. Examples of the block polymer include polystyrene, styrene-acrylic acid ester copolymer, SB-type styrene-butadiene block copolymer and SBS-type styrene-butadiene block copolymer, and hydrogenated products thereof. Examples of the thermoplastic resin include a vinyl polymer and a vinyl copolymer. Examples of the thermosetting resin include an epoxy resin, a phenol resin, and a melamine resin. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, methylcellulose and the like. Soluble resin is preferable, and polyvinyl alcohol is more preferable.

Specific examples of the insulating inorganic material that is the material of the insulating particles include silica and organic-inorganic hybrid particles. The particles formed by the silica are not particularly limited. For example, particles obtained by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, followed by calcination if necessary have. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

The content of the insulating particles in 100 wt% of the conductive material is preferably 0.1 wt% or more, more preferably 0.5 wt% or more, preferably 10 wt% or less, more preferably 5 wt% or less. The conductive material may not contain insulating particles. When the content of the insulating particles is not less than the lower limit and not more than the upper limit, the distance between the connection target members connected by the cured product of the conductive material and the gap between the connection target members connected by the solder in the conductive particles become more appropriate .

(Carbodiimide compound)

From the viewpoint of effectively increasing the transparency and heat resistance of the cured product, it is preferable that the conductive material includes a carbodiimide compound.

Examples of the carbodiimide compound include 1,3-diisopropylcarbodiimide, bis (2,6-diisopropylphenyl) carbodiimide, 1-ethyl-3- (3- dimethylaminopropyl) carbodiimide hydrochloride , N, N'-dicyclohexylcarbodiimide, N, N'-diisopropylcarbodiimide, N-cyclohexyl-N (N'-dicyclohexylcarbodiimide) '' - (2-morpholinoethyl) carbodiimide meth-p-toluenesulfonate, a terminal isocyanate-modified polycarbodiimide compound, a cyclic carbodiimide compound and a carbodiimidization catalyst And a polycarbodiimide compound obtained by subjecting the compound A polycarbodiimide compound is preferable because it has a large molecular weight and is difficult to generate outgas.

Examples of commercially available products of the above-mentioned polycarbodiimide compounds include carbodelite V02B, carbodelite V04K, and carbodelite V05 (both manufactured by Nisshinbo).

From the viewpoint of effectively increasing the transparency and heat resistance of the cured product, the content of the carbodiimide compound in 100 wt% of the conductive material is preferably 0.01 wt% or more, more preferably 0.1 wt% or more, By weight or less, more preferably 3% by weight or less.

(Other components)

The conductive material may contain one or more additives such as a coupling agent, a light shielding agent, a reactive diluent, a defoaming agent, a leveling agent, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, , An ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant.

(Connection structure and manufacturing method of connection structure)

A connection structure according to the present invention comprises a first connection target member having at least one first electrode on its surface, a second connection target member having at least one second electrode on its surface, And a connecting portion connecting the second connection target member. In the connection structure according to the present invention, the material of the connection portion is the above-described conductive material. The connecting portion is a cured product of the above-described conductive material. The connection portion is formed by the above-described conductive material. In the connection structure according to the present invention, the first electrode and the second electrode are electrically connected by a soldering portion in the connection portion.

The method of manufacturing the connection structure may include the steps of disposing the conductive material on the surface of the first connection target member having at least one first electrode on the surface thereof using the conductive material described above, Disposing a second connection target member having at least one second electrode on a surface thereof on a surface opposite to the first connection target member side so that the first electrode and the second electrode face each other; The connecting material connecting the first connection target member and the second connection target member is formed by the conductive material by heating the conductive material at a temperature equal to or higher than the melting point of the solder in the particle, And electrically connecting the second electrode with a soldering portion of the connecting portion. Preferably, the conductive material is heated above the curing temperature of the thermosetting component, the thermosetting compound.

In the connection structure according to the present invention and the method for manufacturing the connection structure, since a specific conductive material is used, the solder in the plurality of conductive particles easily collects between the first electrode and the second electrode, It is possible to efficiently arrange it on the screen. Further, a part of the solder is hardly arranged in a region where no electrode is formed (space), and the amount of solder disposed in an area where no electrode is formed can be significantly reduced. Therefore, the conduction reliability between the first electrode and the second electrode can be improved. In addition, it is possible to prevent electrical connection between adjacent electrodes in the lateral direction which should not be connected, and the insulation reliability can be improved.

In order to efficiently dispose the solder in the plurality of conductive particles on the electrode and considerably reduce the amount of the solder disposed in the region where no electrode is formed, Is preferably used.

The thickness of the solder portion between the electrodes is preferably 10 占 퐉 or more, more preferably 20 占 퐉 or more, preferably 100 占 퐉 or less, and more preferably 80 占 퐉 or less. The wetting area of the solder on the electrode surface (the area where the solder in contact with the exposed area of 100% of the electrode contacts) is preferably 50% or more, more preferably 70% or more, and preferably 100% or less.

In the method of manufacturing a connection structure according to the present invention, in the step of disposing the second connection target member and the step of forming the connection portion, the weight of the second connection target member is It is preferable that the step of disposing the second connection target member and the step of forming the connection portion are such that a pressing pressure exceeding the force of the weight of the second connection object member is not applied to the conductive material desirable. In these cases, the uniformity of the solder amount can be further increased in a plurality of solder portions. In addition, the thickness of the solder portion can be made even thicker, the solder in the plurality of conductive particles can easily gather more between the electrodes, and the solder in the plurality of conductive particles can be more efficiently Can be deployed. Further, a part of the solder in the plurality of conductive particles is hardly arranged in a region where no electrode is formed (space), and the amount of solder in the conductive particles disposed in the region where no electrode is formed is further reduced . Therefore, the conduction reliability between the electrodes can be further enhanced. Furthermore, electrical connection between adjacent electrodes in the lateral direction which should not be connected can be further prevented, and the insulation reliability can be further improved.

In the step of disposing the second connection target member and the step of forming the connection portion, if the weight of the second connection target member is added to the conductive material without applying pressure, The solder arranged in the region (space) where the electrode is not formed is more likely to be gathered between the first electrode and the second electrode, so that the solder in the plurality of conductive particles is arranged more efficiently on the electrode I found out what I could. The present invention employs a combination of using a conductive paste instead of a conductive film and a configuration in which the weight of the second connection target member is added to the conductive paste without applying pressure, There is great significance in getting the effect to a higher level.

In addition, in WO2008 / 023452A1, it is described that, from the viewpoint of efficiently moving solder powder to the surface of the electrode, the solder powder is pressed at a predetermined pressure at the time of bonding, For example, 0 MPa or more, preferably 1 MPa or more, and even if the pressure to be intentionally applied to the adhesive tape is 0 MPa, the self-weight of the member disposed on the adhesive tape may cause It is also possible to apply a pressure of a predetermined pressure to the pressure-sensitive adhesive layer. WO2008 / 023452A1 discloses that the pressure to be intentionally applied to the adhesive tape may be 0 MPa. However, there is no description about the difference in the effect when the pressure exceeding 0 MPa is applied and when the pressure is 0 MPa. Further, in WO2008 / 023452A1, it is not recognized at all about the importance of using a paste-like conductive paste, not a film shape.

When a conductive paste is used instead of a conductive film, it is easy to adjust the thickness of the connecting portion and the solder portion by the amount of application of the conductive paste. On the other hand, in the case of the conductive film, in order to change or adjust the thickness of the connection portion, there is a problem that a conductive film having a different thickness or a conductive film having a predetermined thickness must be prepared. Further, in the conductive film, the melt viscosity of the conductive film can not be sufficiently lowered at the melting temperature of the solder, as compared with the conductive paste, and the agglomeration of the solder tends to be inhibited.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

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

The connection structure 1 shown in Fig. 1 has a structure in which the first connection target member 2, the second connection target member 3, the first connection target member 2 and the second connection target member 3 are connected (Not shown). The connecting portion 4 is formed by the above-described conductive material. In the present embodiment, the conductive material includes conductive particles and a binder. In the present embodiment, the conductive material includes solder particles as conductive particles. In the present embodiment, the binder includes a thermosetting compound and a thermosetting agent. The thermosetting compound and the thermosetting agent are referred to as a thermosetting component.

The connecting portion 4 has a soldering portion 4A in which a plurality of solder particles are gathered and joined together and a cured portion 4B in which a thermosetting component is thermally cured.

The first connection target member 2 has a plurality of first electrodes 2a on its surface (upper surface). The second connection target member 3 has a plurality of second electrodes 3a on its surface (lower surface). The first electrode 2a and the second electrode 3a are electrically connected by the solder portion 4A. Therefore, the first connection target member 2 and the second connection target member 3 are electrically connected by the soldering portion 4A. In the connecting portion 4, there is no solder in a region different from the soldering portion 4A gathered between the first electrode 2a and the second electrode 3a (cured portion 4B). There is no solder spaced apart from the soldering portion 4A in the region different from the soldering portion 4A (portion of the hardened portion 4B). If it is a small amount, solder may be present in a region (cured portion 4B) different from the soldering portion 4A gathered between the first electrode 2a and the second electrode 3a.

As shown in Fig. 1, in the connection structure 1, a plurality of solder particles are collected between the first electrode 2a and the second electrode 3a, and a plurality of solder particles are melted, The solder paste is solidified after being spread on the surface of the electrode, and a soldering portion 4A is formed. Therefore, the connection area between the solder portion 4A and the first electrode 2a, and between the solder portion 4A and the second electrode 3a is increased. That is, by using the solder particles, the solder portion 4A and the first electrode 2a, and the solder portion 4A (solder paste) are used as compared with the case where the outer surface portion of the conductive portion is made of metal such as nickel, gold, And the second electrode 3a is increased. For this reason, conduction reliability and connection reliability in the connection structure 1 are improved.

In the connection structure 1 shown in Fig. 1, all of the soldering portions 4A are located in the regions where the first and second electrodes 2a and 3a face each other. In the connection structure 1X of the modification shown in Fig. 3, only the connection portion 4X is different from the connection structure 1 shown in Fig. The connecting portion 4X has a soldering portion 4XA and a cured portion 4XB. Most of the soldering portion 4XA is located in the region where the first and second electrodes 2a and 3a face each other and the soldering portion 4XA is part of the first and second electrodes 2a and 3a, But may be sideways from the opposed regions of the electrodes 2a and 3a. The soldering portion 4XA that is sideways away from the opposing region of the first and second electrodes 2a and 3a is part of the soldering portion 4XA and is not solder spaced apart from the soldering portion 4XA . In the present embodiment, the amount of solder spaced apart from the solder portion can be reduced, but solder spaced from the solder portion may be present in the hardened portion.

When the usage amount of the solder particles is reduced, it is easy to obtain the connection structure 1. If the amount of solder particles used is increased, it is easy to obtain the connection structure 1X.

The connection structures 1 and 1X are provided with the first electrodes 2a and the first electrodes 2a in the stacking direction of the first electrodes 2a and the connection portions 4 and 4X and the second electrodes 3a, It is preferable that at least 50% of the area 100% of the mutually opposing portions of the first electrode 2a and the second electrode 3a should be soldered in the connecting portions 4 and 4X, It is preferable that the lead portions 4A and 4XA are disposed.

When viewed from mutually facing portions of the first electrode and the second electrode in the stacking direction of the first electrode, the connection portion, and the second electrode, from the viewpoint of further enhancing conduction reliability, (More preferably 60% or more, more preferably 70% or more, particularly preferably 80% or more, and most preferably 90% or more) of 100% of the areas of mutually opposing two electrodes. It is preferable that a solder portion in the connecting portion is disposed.

In view of further enhancing the conduction reliability, when the mutually facing portions of the first electrode and the second electrode facing each other in the direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, (More preferably at least 70%, more preferably at least 90%, particularly preferably at least 95%, most preferably at least 90%, most preferably at least 90%, most preferably at least 90% Is more than 99%).

Next, an example of a method of manufacturing the connection structure 1 using the conductive material according to one embodiment of the present invention will be described.

First, a first connection target member 2 having a first electrode 2a on its surface (upper surface) is prepared. Next, as shown in Fig. 2A, a thermosetting component 11B and a conductive material 11 including a plurality of solder particles 11A are placed on the surface of the first connection target member 2 (First step). The conductive material used includes a thermosetting compound and a thermosetting agent as the thermosetting component 11B.

The conductive material 11 is disposed on the surface of the first connection target member 2 on which the first electrode 2a is provided. After the conductive material 11 is disposed, the solder particles 11A are disposed on both the first electrode 2a (line) and the region where the first electrode 2a is not formed (space).

The method for disposing the conductive material 11 is not particularly limited, and examples thereof include coating with a dispenser, screen printing, and ejection with an inkjet apparatus.

Furthermore, a second connection target member 3 having a second electrode 3a on its surface (lower surface) is prepared. 2 (b), in the conductive material 11 on the surface of the first connection target member 2, a portion of the conductive material 11 opposite to the first connection target member 2 side The second connection target member 3 is arranged on the surface (second step). The second connection target member 3 is disposed on the surface of the conductive material 11 from the second electrode 3a side. At this time, the first electrode 2a and the second electrode 3a are opposed to each other.

Subsequently, the conductive material 11 is heated to a temperature equal to or higher than the melting point of the solder particles 11A (third step). Preferably, the conductive material 11 is heated to a temperature not lower than the curing temperature of the thermosetting component 11B (thermosetting compound). During the heating, the solder particles 11A existing in the regions where the electrodes are not formed are gathered between the first electrode 2a and the second electrode 3a (magnetic cohesion effect). When a conductive paste is used instead of a conductive film, solder particles 11A are effectively gathered between the first electrode 2a and the second electrode 3a. Further, the solder particles 11A are melted and bonded to each other. Further, the thermosetting component 11B is thermally cured. As a result, as shown in Fig. 2 (c), the connection portion 4 connecting the first connection target member 2 and the second connection target member 3 is formed by the conductive material 11 . The connecting portion 4 is formed by the conductive material 11 and the solder portion 4A is formed by bonding a plurality of solder particles 11A to thermally cure the thermosetting component 11B, . When the solder particles 11A sufficiently move, the movement of the solder particles 11A, which are not located between the first electrode 2a and the second electrode 3a, starts, and then the first electrode 2a and the second electrode 3a, It is not necessary to keep the temperature constant until the movement of the solder particles 11A is completed between the solder balls 3a.

In the present embodiment, it is preferable that no pressure is applied in the second step and the third step. In this case, the weight of the second connection target member 3 is added to the conductive material 11. Therefore, at the time of forming the connecting portion 4, the solder particles 11A effectively gather between the first electrode 2a and the second electrode 3a. When the pressing is performed in at least one of the second step and the third step, the tendency that the action of the solder particles 11A to gather between the first electrode 2a and the second electrode 3a is inhibited .

Further, in this embodiment, when the second connection target member is superimposed on the first connection target member to which the conductive material is applied, the first connection target member and the second connection target member are not pressurized, Even if the first connection target member and the second connection target member are overlapped with each other in the state where the alignment of the electrodes of the target member is shifted, the misalignment is corrected so that the electrodes of the first connection target member and the electrodes of the second connection target member (Self-alignment effect). This is because the molten solder magnetically agglomerated between the electrode of the first connection target member and the electrode of the second connection target member is soldered between the electrode of the first connection target member and the electrode of the second connection target member, This is because the area where the components contact with each other becomes the minimum is stabilized energetically, so that a force of the alignment connecting structure which is the minimum area is applied. At this time, it is preferable that the conductive material is not cured and that the viscosity of components other than the conductive particles of the conductive material is sufficiently low at the temperature and time.

In this way, the connection structure 1 shown in Fig. 1 is obtained. Further, the second step and the third step may be performed continuously. After the second step is performed, the resulting laminate of the first connection target member 2, the conductive material 11, and the second connection target member 3 is moved to the heating portion, and the third step is performed . In order to perform the heating, the laminate may be disposed on the heating member, or the laminate may be disposed in the heated space.

The heating temperature in the third step is preferably 140 占 폚 or higher, more preferably 160 占 폚 or higher, preferably 450 占 폚 or lower, more preferably 250 占 폚 or lower, still more preferably 200 占 폚 or lower to be.

As the heating method in the third step, the entire connection structure may be heated by using a reflow furnace or an oven at a temperature not lower than the melting point of the solder and not lower than the hardening temperature of the thermosetting compound, And a method of local heating.

The first and second connection target members are not particularly limited. Specific examples of the first and second connection target members include semiconductor chips, semiconductor packages, LED chips, LED packages, electronic components such as capacitors and diodes, resin films, printed boards, flexible printed boards, flexible flat cables, An electronic component such as a rigid flexible substrate, a glass epoxy substrate, and a circuit substrate such as a glass substrate. It is preferable that the first and second connection target members are electronic parts.

It is preferable that at least one of the first connection target member and the second connection target member is a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate. It is preferable that the second connection target member is a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate. The resin film, the flexible printed circuit board, the flexible flat cable, and the rigid flexible substrate have high flexibility and relatively light weight properties. When a conductive film is used for connecting the connection target member, the solder tends to be difficult to collect on the electrode. By using the conductive paste, on the other hand, even if a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate is used, the reliability of conduction between the electrodes can be sufficiently improved by collecting the solder efficiently on the electrode. In the case of using a resin film, a flexible printed circuit board, a flexible flat cable or a rigid flexible substrate, the effect of improving the conduction reliability between the electrodes by not pressing is further improved as compared with the case of using other members to be connected such as semiconductor chips .

Examples of the electrode provided on the member to be connected include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes, SUS electrodes and tungsten electrodes. When the connection target member is a flexible printed circuit board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode, or a copper electrode. When the member to be connected is a glass substrate, it is preferable that the electrode is an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. When the electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode in which an aluminum layer is laminated on the surface of the metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al, and Ga.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. The present invention is not limited to the following embodiments.

(1) Synthesis of thermosetting compound A having a thiirane group and a triazine skeleton:

In a container equipped with a stirrer, a condenser and a thermometer, 1100 mL of methanol and 400 g of trimethylthiourea were added to prepare a first solution in a vessel. Thereafter, the temperature in the container was maintained at 60 캜.

Subsequently, 600 g of TEPIC-VL (manufactured by Nissan Chemical Industries, Ltd.) and 3600 ml of toluene were placed in the first solution while stirring the first solution maintained at 60 占 폚, and the mixture was further stirred for 30 minutes to obtain an epoxy compound-containing solution .

Then, the epoxy compound-containing solution was reacted at 60 DEG C for 5 hours under a nitrogen flow while stirring. Thereafter, the solution in the vessel was transferred to a separating funnel, allowed to stand for 2 hours, and the solution was separated. The solution in the lower portion of the separating funnel was discharged, and the supernatant was taken out. 950 mL of toluene was added to the supernatant taken out, stirred, and allowed to stand for 2 hours.

Subsequently, pure water was added to the supernatant to which toluene had been added, and the solution was washed by repeating stirring and discharging the solution downward.

Thereafter, 200 g of magnesium sulfate was added to the supernatant, and the mixture was stirred for 5 minutes. After stirring, the magnesium sulfate was removed by a filter paper, and the solution was separated. The remaining solvent was removed by vacuum drying using a vacuum drier. Thus, a thermosetting compound A having a thiazine group and a triazine skeleton was obtained.

¹ H-NMR measurement of the obtained thermosetting compound A was performed using chloroform as a solvent. As a result, it was confirmed that the epoxy group was converted into an episulfide group.

(2) Synthesis of thermosetting compound B having thiirane group and triazine skeleton:

Except that TEPIC-VL (manufactured by Nissan Chemical Industries, Ltd.) was changed to TEPIC-HP (manufactured by Nissan Chemical Industries, Ltd.) and the temperature in the vessel was changed to 80 캜. A thermosetting compound B having an azine skeleton was obtained.

¹ H-NMR measurement of the obtained thermosetting compound B was carried out using chloroform as a solvent. As a result, it was confirmed that the epoxy group was converted into an episulfide group. The melting point of the obtained thermosetting compound B was 150 캜.

Thermosetting compound 1: Epoxy compound "EP-3300" manufactured by Adeka Co., epoxy equivalent weight 160 g / eq

Thermosetting compound 2: epoxy compound, "TEPIC-SS" manufactured by Nissan Chemical Industries, Ltd., epoxy equivalent weight 100 g / eq

Thermosetting compound 3: epoxy compound, "TEPIC-VL" manufactured by Nissan Chemical Industries, Ltd., epoxy equivalent weight 135 g / eq

Thermal curing agent 1: trimethylolpropane tris (3-mercaptopropionate), TM TM manufactured by Yuki Kagaku Co., Ltd.

Latent epoxy thermosetting agent 1: Fujikure 7000 manufactured by T & K TOKA

Latent epoxy thermosetting agent 2: " HXA-3922HP " manufactured by Asahi Kasei Immeltilizers

Synthesis of flux 1:

25 parts by weight of glutaric acid and 25 parts by weight of monomethyl glutarate were placed in a three-necked flask and dissolved at 80 占 폚 under a nitrogen flow. Thereafter, 57 parts by weight of benzylamine was added and reacted at 150 캜 for 2 hours under reduced pressure to obtain a flux 1 having an amide group which was solid at 25 캜.

Flux 2: monomethyl glutarate, manufactured by Wako Pure Chemical Industries, Ltd.

Insulating particles: average particle diameter 30 占 퐉, CV value 5%, softening point 330 占 폚, divinylbenzene crosslinked particles manufactured by Sekisui Chemical Co., Ltd.

Carbodiimide Compound 1: Carbodilite V02B (manufactured by Nisshinbo)

Manufacturing Method of Solder Particle 1:

, 20 g of a silane coupling agent having an isocyanate group (" KBE-9007 ", manufactured by Shin-Etsu Silicone Co., Ltd.) and 70 g of acetone were charged into three portions of SnBi solder particles (DS- The flask was weighed. While stirring at room temperature, 0.25 g of dibutyltin laurate as a reaction catalyst between the hydroxyl group and the isocyanate group on the surface of the solder particles was added and the mixture was heated at 100 ° C for 2 hours under a nitrogen atmosphere with stirring. Then, 120 g of methanol and 0.05 g of acetic acid were added, and the mixture was heated at 60 占 폚 for 1 hour under a nitrogen atmosphere with stirring.

Thereafter, the resultant was cooled to room temperature, the solder particles were filtered with a filter paper, and the solvent was removed by vacuum drying at room temperature for 1 hour to obtain solder particles.

The above solder particles were put in a three-necked flask, and 45 g of acetone, 40 g of monoethyl adipate and 0.2 g of dimethyisilylammonium pentafluorobenzenesulfonate were added and reacted at 65 DEG C for 1 hour under nitrogen atmosphere with stirring Thereafter, the solvent was removed by vacuum drying.

Thereafter, the solder particles were placed in a three-necked flask, and 85 g of acetone, 40 g of adipic acid and 0.5 g of lanthanum isopropoxide were added, reacted at 65 DEG C for 1 hour, cooled to room temperature, The particles were filtered, and the solder particles were washed twice with acetone and once with hexane on a filter paper, followed by vacuum drying for 1 hour at room temperature.

After the obtained solder particles were broken with a ball mill, a sieve was selected so as to have a predetermined CV value.

Thus, the solder particles 1 were obtained. The obtained solder particles 1 had a CV value of 20% and an acid value of 0.5 mg / KOH.

Manufacturing Method of Solder Particle 2:

The solder particles 2 were prepared in the same manner as the solder particles 1 except that the solder particles were washed once with hexane on the filter paper. The obtained solder particles 2 had a CV value of 20% and an acid value of 13 mg / KOH.

Solder particles A (SnBi solder particles, melting point 139 占 폚, DS-10 made by Mitsui Kinzoku Co., average particle diameter (median diameter 12 占 퐉)), acid value: 0.2 mg / KOH

(CV value of solder particles)

The CV value was measured by a laser diffraction particle size distribution measuring apparatus (" LA-920 " manufactured by Horiba Seisakusho Co., Ltd.).

(Acid value of solder particles)

Phenolphthalein was added to ethanol, and 50 ml of the solution neutralized with 0.1 N-KOH was added with 1 g of conductive particles (solder particles), dispersed by ultrasonic treatment, and titrated with 0.1 N-KOH to obtain acid value.

(Examples 1 to 5 and Comparative Examples 1 to 3)

(1) Fabrication of anisotropic conductive paste

The components shown in the following Table 1 were compounded in the amounts shown in Table 1 to obtain an anisotropic conductive paste.

The connection structure was manufactured as follows.

(2) Fabrication of connection structure (L / S = 75 탆 / 75 탆)

A glass epoxy substrate (FR-4 substrate, thickness 0.6 mm) (first connection target member) having a copper electrode pattern (copper electrode thickness of 12 탆) having an L / S of 75 탆 / Prepared. Further, a flexible printed circuit board having a copper electrode pattern (thickness of copper electrode: 12 mu m) having an L / S of 75 mu m / 75 mu m and an electrode length of 3 mm was formed on a flexible printed circuit board mm).

The overlapping area of the glass epoxy substrate and the flexible printed substrate was 1.5 cm x 3 mm, and the number of electrodes connected was 75 pairs.

An anisotropic conductive paste immediately after preparation was coated on the upper surface of the glass epoxy substrate so as to have a thickness of 100 mu m on the electrode of the glass epoxy substrate to form an anisotropic conductive paste layer. Subsequently, the flexible printed circuit board was laminated on the upper surface of the anisotropic conductive paste layer so that the electrodes were opposed to each other. While the heating head was placed on the upper surface of the flexible printed circuit board and the temperature was raised from room temperature to 180 ° C, And the solder particles were agglomerated and melted between the upper and lower electrodes and further heated at 180 캜 for 10 seconds to cure the anisotropic conductive paste layer to obtain a connection structure. At this time, the weight of the flexible printed circuit board and the pressure to the extent that the flexible printed circuit board does not bend are applied to the anisotropic conductive paste layer.

(evaluation)

(1) Viscosity

The viscosity (? 25) of the anisotropic conductive paste immediately after preparation was measured at 25 占 폚 at 25 占 폚 and 5 rpm using an E-type viscometer (TVE22L manufactured by Axis Industries, Inc.).

(2) Storage stability

The anisotropic conductive paste was stored at 23 占 폚 for 24 hours. After storage, the viscosity (? 25) of the anisotropic conductive paste at 25 占 폚 was measured under the conditions of 25 占 폚 and 5 rpm using an E-type viscometer (TVE22L manufactured by Axis Corporation). Storage stability was judged based on the following criteria.

[Criteria for storage stability]

○○: viscosity after storage / viscosity before storage less than 1.2 times

○: viscosity after storage / viscosity before storage 1.2 times or more and 1.5 times or less

Δ: viscosity after storage / viscosity before storage 1.5 times or more and less than 2 times

X: Viscosity after storage / viscosity before storage 2 times or more

(3) Prevention of spillage of components other than conductive particles

In the obtained connecting structure, the length of the part protruding from the electrode was observed and measured by a microscope to evaluate the leakage preventing property of the components excluding the conductive particles. The leakage inhibiting properties of the components other than the conductive particles were judged based on the following criteria.

[Criteria for preventing leakage of components other than conductive particles]

○ ○: The length of the portion which is emanated from the electrode is less than 150 μm

?: The length of a portion that is hollowed out from the electrode is 150 占 퐉 or more and less than 200 占 퐉

DELTA: length of a portion which is hollowed out from the electrode is 200 mu m or more and less than 300 mu m

X: length of a portion which is vacated from the electrode is 300 mu m or more

(4) Thickness of the soldering portion

The thicknesses of the solder portions positioned between the upper and lower electrodes were evaluated by observing the cross section of the obtained connection structure.

(5) Arrangement accuracy of solder on electrode 1

In the obtained connecting structure, when the mutually opposing portions of the first electrode and the second electrode in the lamination direction of the first electrode, the connecting portion and the second electrode are observed, the area of the mutually facing portions of the first electrode and the second electrode %, The ratio X of the area where the solder portion is arranged in the connection portion was evaluated. The placement accuracy 1 of the solder on the electrode was judged based on the following criteria.

[Criteria for Arrangement Precision 1 of Solder on Electrode]

○○: ratio X is 70% or more

○: ratio X is 60% or more and less than 70%

DELTA: ratio X is 50% or more and less than 60%

X: ratio X is less than 50%

(6) Arrangement accuracy of solder on electrode 2

In the obtained connecting structure, when the portions of the first electrode and the second electrode facing each other in the direction orthogonal to the stacking direction of the first electrode, the connecting portion and the second electrode are observed, among the solder 100% And the ratio Y of the solder portion in the connection portion disposed in the mutually opposing portion of the second electrode were evaluated. The placement accuracy 2 of the solder on the electrode was determined based on the following criteria.

[Criteria for Arrangement Accuracy 2 of Solder on Electrode]

○○: 99% or more of ratio Y

○: The ratio Y is 90% or more and less than 99%

DELTA: ratio Y is 70% or more and less than 90%

X: ratio Y is less than 70%

(7) Reliability of conduction between upper and lower electrodes

In the obtained connecting structures (n = 15), the connection resistances per connection portion between the upper and lower electrodes were measured by the four-terminal method. And the average value of the connection resistance was calculated. From the relationship of voltage = current x resistance, the connection resistance can be obtained by measuring the voltage when a constant current is passed. The conduction reliability was judged based on the following criteria.

[Criteria for reliability of conduction]

○○: Average value of connection resistance is less than 50mΩ

?: The average value of the connection resistance exceeds 50 m? And is 70 m?

DELTA: average value of connection resistance exceeding 70 m? And not exceeding 100 m?

×: Average value of connection resistance exceeds 100 mΩ or connection failure occurs

(8) Insulation reliability between electrodes adjacent in the transverse direction

In the obtained connecting structure (n = 15), after leaving for 100 hours in an atmosphere at 85 캜 and a humidity of 85%, 15 V was applied between adjacent electrodes in the transverse direction, and the resistance value was measured at 25 places. The insulation reliability was judged based on the following criteria.

[Judgment Criteria of Insulation Reliability]

○○○: Average value of connection resistance is more than 10 ¹⁴ Ω

○○: average value of connection resistance is more than 10 ⁸ Ω and less than 10 ¹⁴ Ω

○: The average value of the contact resistance more than 10 ⁶ Ω is less than 10 ⁸ Ω

△: average value of connection resistance is 10 ⁵ Ω or more and less than 10 ⁶ Ω

X: Average value of connection resistance is less than 10 ⁵ Ω

(9) Position deviation between upper and lower electrodes

In the obtained connecting structure, when the mutually opposing portions of the first electrode and the second electrode in the stacking direction of the first electrode, the connecting portion and the second electrode are viewed, the center line of the first electrode and the center line of the second electrode are aligned And the distance of the positional deviation were evaluated. The positional deviation between the upper and lower electrodes was determined based on the following criteria.

[Criteria for judging positional displacement between upper and lower electrodes]

○○: Position deviation is less than 15 탆

?: The positional deviation is not less than 15 占 퐉 and less than 25 占 퐉

DELTA: Position deviation is 25 占 퐉 or more and less than 40 占 퐉

X: position deviation is 40 占 퐉 or more

(10) Heat resistance (heat-resistant yellowing)

In the formulation components shown in the following Table 1, blends containing components other than the solder particles in the conductive paste were prepared to prepare a cured sheet having a thickness of 0.6 mm. After storing at 150 DEG C for 2000 hours, the transmittance at a measurement wavelength of 400 nm was measured to evaluate heat resistance (heat resistance yellowing). The heat resistance was judged based on the following criteria.

[Judgment criteria for heat resistance]

○○: The transmittance after storage at high temperature is 93% or more

○: transmittance after high temperature storage is 90% or more and less than 93%

?: Transmittance after storage at high temperature of 87% or more and less than 90%

×: Not equivalent to the criterion of ○ ○, ○ and Δ

The results are shown in Table 1 below.

The same tendency was seen in the case of using a resin film, a flexible flat cable and a rigid flexible substrate instead of the flexible printed substrate.

1, 1X ... Connection structure
2… The first connection object member
2a ... The first electrode
3 ... The second connection object member
3a ... The second electrode
4, 4X ... Connection
4A, 4XA ... Soldering portion
4B, 4XB ... Hardened portion
11 ... Conductive material
11A ... Solder particles (conductive particles)
11B ... Thermosetting component
21 ... Conductive particles (solder particles)
31 ... Conductive particle
32 ... Base particles
33 ... The conductive portion (conductive portion having solder)
33A ... The second conductive portion
33B ... Soldering portion
41 ... Conductive particle
42 ... Soldering portion

Claims (15)

A plurality of conductive particles having a solder on an outer surface portion of the conductive portion,
Thermosetting compounds,
A thermosetting agent,
Wherein the thermosetting compound comprises a thermosetting compound having a thiirane group and a triazine skeleton. The conductive material according to claim 1, wherein the melting point of the thermosetting compound having a thiadiene group and a triazine skeleton is 140 占 폚 or higher. The conductive material according to any one of claims 1 to 3, further comprising a thermosetting compound different from the thermosetting compound having a thiirane group and a triazine skeleton. The conductive material according to any one of claims 1 to 3, wherein the acid value of the conductive particles is 0.1 mg / KOH or more and 10 mg / KOH or less. The conductive material according to any one of claims 1 to 4, comprising a flux. 6. The conductive material according to claim 5, wherein the flux is a flux that is a flux having an amide group and an aromatic skeleton, or is a reactant of an amino group-containing compound having an amide group and having a pKa of 9.5 or less with a carboxylic acid or a carboxylic acid anhydride. 7. The conductive material according to claim 5 or 6, wherein the flux is solid at 25 占 폚. 8. The conductive material according to any one of claims 1 to 7, comprising a carbodiimide compound. The conductive material according to any one of claims 1 to 8, wherein the conductive particles are solder particles. 10. The conductive material according to any one of claims 1 to 9, comprising insulating particles not adhered to the surface of the conductive particles. 11. The conductive material according to any one of claims 1 to 10, wherein the conductive particles have an average particle diameter of 1 占 퐉 or more and 40 占 퐉 or less. 12. The conductive material according to any one of claims 1 to 11, wherein the content of the conductive particles in the conductive material is 100 wt% or more and 10 wt% or more and 80 wt% or less. 13. The conductive material according to any one of claims 1 to 12, which is liquid at 25 DEG C and is a conductive paste. A first connection target member having at least one first electrode on its surface,
A second connection object member having at least one second electrode on its surface,
And a connecting portion connecting the first connection target member and the second connection target member,
Wherein the material of the connecting portion is the conductive material according to any one of claims 1 to 13,
And the first electrode and the second electrode are electrically connected to each other by the solder portion in the connection portion. 15. The method according to claim 14, wherein when viewing the mutually opposing portions of the first electrode and the second electrode in the stacking direction of the first electrode, the connection portion, and the second electrode, Wherein a solder portion in the connection portion is disposed at 50% or more of an area of 100% of a portion facing each other.

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