KR20180044224A - Conductive material and connection structure - Google Patents

Abstract

Provided is a conductive material capable of suppressing generation of black soot in a cured product, selectively arranging solder in conductive particles on the electrode, and improving conduction reliability. [MEANS FOR SOLVING PROBLEMS] A conductive material according to the present invention is a conductive material which comprises a plurality of conductive particles having a solder, a thermosetting component, and a flux on an outer surface portion of a conductive portion, wherein the thermosetting component or the flux has an isocyanurate skeleton , And the viscosity of the conductive material at the melting point of the solder in the conductive particle is 0.1 Pa · s or more and 20 Pa · s or less.

Description

Conductive material and connection structure

The present invention relates to a conductive material containing 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, the 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) and thallium (Tl), and 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, Are electrically connected to each other. In addition, Patent Document 1 describes that mounting is performed with the temperature profile shown in Fig. 8 of Patent Document 1. In Patent Document 1, the conductive particles are melted in the resin component in which 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. This adhesive tape is in the form of a film, not a paste.

Japanese Patent Application Laid-Open No. 2004-260131 WO 2008/023452 A1

The present inventors have found that a conventional solder powder or an anisotropic conductive material containing conductive particles having a solder layer on its surface may contain black soot derived from solder in the cured product of the anisotropic conductive material . Especially, when the solder is subjected to the flux action by the flux, black soot tends to occur. This black soot increases the connection resistance between the electrodes, thereby lowering the conduction reliability.

Further, when the anisotropic conductive material described in Patent Document 1 is used to electrically connect the electrodes by the method described in Patent Document 1, conductive particles including solder may not be efficiently arranged on the electrode (line). Further, in the embodiment of Patent Document 1, at a temperature equal to or higher than the melting point of the solder, the solder is maintained at a constant temperature for sufficiently moving the solder, thereby lowering the manufacturing efficiency of the connection structure. When mounting is performed with the temperature profile shown in Fig. 8 of Patent Document 1, the manufacturing efficiency of the connection structure is lowered.

The adhesive tape described in Patent Document 2 is in the form of a film, not a paste. In the adhesive tape having the composition as described in Patent Document 2, it is difficult to efficiently dispose the solder powder on the electrode (line). For example, in the adhesive tape described in Patent Document 2, a part of the solder powder is likely to be disposed in an area (space) where no electrode is formed. The solder powder disposed in the region where no electrode is formed does not contribute to conduction between the electrodes.

An object of the present invention is to provide a conductive material capable of suppressing the generation of black soot in a cured product and capable of selectively disposing solder in the conductive particles on the electrode, thereby improving conduction reliability. 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, there is provided a method of manufacturing a semiconductor device, which comprises a plurality of conductive particles having solder, a thermosetting component, and a flux, and a compound having an isocyanurate skeleton as the thermosetting component or the flux And the viscosity of the conductive material at the melting point of the solder in the conductive particles is 0.1 Pa · s or more and 20 Pa · s or less.

The weight ratio of the content of the compound having an isocyanurate skeleton to the content of the flux is preferably 0.5 or more and 20 or less. The weight ratio of the content of the compound having an isocyanurate skeleton to the content of the conductive particles is preferably 0.05 or more and 0.5 or less.

In a specific aspect of the conductive material according to the present invention, the molecular weight of the compound having an isocyanurate skeleton is 200 or more and 1000 or less.

In a specific aspect of the conductive material according to the present invention, the conductive material includes, as the thermosetting component, a thermosetting compound having an isocyanurate skeleton or a thermosetting agent having an isocyanurate skeleton.

In a specific aspect of the conductive material according to the present invention, the conductive material includes a thermosetting compound having an isocyanurate skeleton as the thermosetting component.

In a specific aspect of the conductive material according to the present invention, the conductive material includes a thermosetting compound having no isocyanurate skeleton as the thermosetting component.

In a specific aspect of the conductive material according to the present invention, the thermosetting component includes a thermosetting compound having an isocyanurate skeleton and a thermosetting compound having no isocyanurate skeleton.

In a specific aspect of the conductive material according to the present invention, the thermosetting compound having no isocyanurate skeleton is a thermosetting compound having no isocyanurate skeleton and having an aromatic skeleton or alicyclic skeleton.

In a specific aspect of the conductive material according to the present invention, the conductive material includes a phosphoric acid 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 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 the connection portion is a cured product of the conductive material, and the first electrode and the second electrode are electrically connected to each other by the solder portion in the connection portion, A connection 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 a solder portion in the connection portion is disposed in 50% or more of an area of 100% of portions of the electrodes facing each other facing the second electrode.

The conductive material according to the present invention includes a compound having an isocyanurate skeleton as the above-mentioned thermosetting component or flux, a plurality of conductive particles having solder on the outer surface portion of the conductive portion, a thermosetting component, and a flux And the viscosity of the conductive material at the melting point of the solder in the conductive particles is not less than 0.1Pa · s and not more than 20Pa · s so that occurrence of black soot can be suppressed in the cured product of the conductive material. In addition, the solder in the conductive particles can be selectively disposed on the electrode, and the conduction reliability can be improved.

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 respective steps 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 modified example of the connection structure.
4 is a cross-sectional view showing a first example of conductive particles usable for a conductive material.
5 is a cross-sectional view showing a second example of conductive particles usable in a conductive material.
6 is a cross-sectional view showing a third example of conductive particles usable for a conductive material.

Hereinafter, the details of the present invention will be described.

(Conductive material)

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

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

The conductive material according to the present invention includes, as the thermosetting component or the flux, a compound having an isocyanurate skeleton. The compound having an isocyanurate skeleton may be a thermosetting component having an isocyanurate skeleton, a flux having an isocyanurate skeleton, a thermosetting compound having an isocyanurate skeleton or a thermosetting agent having an isocyanurate skeleton . The thermosetting component having the isocyanurate skeleton may be a thermosetting compound having an isocyanurate skeleton or a thermosetting agent having an isocyanurate skeleton.

In the conductive material according to the present invention, the viscosity of the conductive material at the melting point of the solder in the conductive particles is 0.1 Pa · s or more and 20 Pa · s or less.

In the present invention, since the above structure is provided, it is possible to suppress black soot derived from solder in the cured product of the conductive material. When black soot is contained in the cured product of the conductive material, the connection resistance between the electrodes is increased, and the reliability of conduction is lowered. In the present invention, generation of black soot can be suppressed, so that the connection resistance between the electrodes can be made low, and the reliability of conduction can be enhanced.

Further, in the present invention, since the above-described configuration is provided, in particular, since the viscosity of the conductive particles of the conductive material at the melting point of the solder is within the above-mentioned range, solder in the conductive particles is selectively Can be deployed. When the electrodes are electrically connected, the solder in the conductive particles tends to collect between the upper and lower opposing electrodes, so that the solder in the conductive particles can be efficiently arranged on the electrode (line).

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 transverse direction which should not be connected, and the insulation reliability can be improved.

In order to more effectively arrange the solder on the electrode, the conductive material is preferably liquid at 25 DEG C and is preferably a conductive paste.

In order to efficiently dispose the solder on the electrode, the viscosity of the conductive material at the melting point of the solder in the conductive particle is not less than 0.1 Pa · s and not more than 20 Pa · s. From the viewpoint of more efficiently placing the solder on the electrode, the viscosity? Mp is preferably 1 Pa · s or more, preferably 15 Pa · s or less, more preferably 10 Pa · s or less. When the viscosity (? Mp) is equal to or more than the lower limit and the upper limit, the conductive particles or solder move efficiently from the initial stage to the middle stage at the time of conductive connection.

The viscosity was measured at a strain rate of 1 rad, a frequency of 1 Hz, a temperature raising rate of 20 DEG C / min, and a measurement temperature range of 40 to 200 DEG C (provided that solder The upper limit of the temperature is defined as the melting point of the solder). The melting point of the solder may be 200 占 폚 or less.

The conductive material can be used as a conductive paste and a conductive film. The conductive material is preferably an anisotropic conductive material. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film. The conductive material is suitably used for electrical connection of electrodes. The conductive material is preferably a circuit connecting material.

From the viewpoint of further suppressing the occurrence of black soot, the molecular weight of the compound having an isocyanurate skeleton is preferably 200 or more, more preferably 300 or more, preferably 1000 or less, more preferably 600 or less to be.

From the viewpoint of further suppressing the occurrence of black soot, the content of the compound having an isocyanurate skeleton in 100 wt% of the conductive material is preferably at least 5 wt%, more preferably at least 10 wt% Preferably 30% by weight or less, more preferably 20% by weight or less.

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. The solder particles are formed by solder. The solder particles have solder on the outer surface portion of the conductive portion. The solder particle is a solder particle in which both the center portion of the solder particle and the outer surface portion of the conductive portion are solder. In the solder particles, both the central portion and the outer surface portion of the conductive portion are formed by solder. The conductive particles may have a base particle and a conductive portion disposed on the surface of the base particle. In this case, the conductive particles have solder on the outer surface portion of the conductive portion.

In addition, 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 do not easily gather on the electrodes, The conductive particles moved on the electrode tends to move to the outside of the electrode because the solder bonding property is low and the effect of suppressing the positional deviation between the electrodes tends to be lowered. Therefore, the conductive particles are preferably solder particles.

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) , A carboxyl group or a group containing an amino group is covalently bonded through 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 is lowered and the generation of voids is suppressed Possible conductive particles are obtained.

In the conductive particles, a coordination bond is not necessarily included in the solder surface and a bond form of a group containing a carboxyl group, and binding due to the chelate coordination is not required.

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 conductive 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 compound having a flux action may be used alone or in combination of two or more.

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. 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 in which the nitrogen atom of the group derived from the isocyanate group is 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 to the surface of the solder through the group represented by the formula (X) by reacting the compound with the solder surface and then 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 residual unsaturated double bond and having a carboxyl group to form a carboxyl group on the surface of the solder through the group represented by the formula Can be introduced.

Examples of the silane coupling agent include 3-isocyanate propyltriethoxysilane (KBE-9007 manufactured by Shinetsu Silicone Co., Ltd.) and 3-isocyanate propyl trimethoxysilane (Y-5187 manufactured by MOMENTIVE) . The silane coupling agent may be used alone 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 a hydroxyl group on the surface of the solder using conductive particles, and an isocyanate compound is reacted with a compound having at least one carboxyl group, 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 using a reaction catalyst of a hydroxyl group and an 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 between 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 lowering 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 a 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 anionic polymer may be used singly or in combination of two or more kinds. 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 a method of reacting the carboxyl group of the anionic polymer with the hydroxyl group on the surface of the conductive particle body using vinyl alcohol ("Gosenel T" manufactured by Nippon Kagaku Co., Ltd.).

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 the surface treatment is to use a compound having a functional group reactive with the hydroxyl group on the surface of the conductive particle body and having a functional group capable of being polymerized by addition or condensation reaction, 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. As a result, the cohesiveness of the conductive particles can be effectively increased during the conductive connection, and the oxide film on the electrode surface 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 solder particles at the time of conductive connection, It can be arranged 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 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 anionic polymer and then measuring the weight average molecular weight of the remaining anionic polymer.

The amount of the conductive polymer to be introduced into the surface of the conductive particles is preferably 1 mgKOH or more, more preferably 2 mgKOH or more, and more preferably 10 mgKOH or less, per 1 g of the conductive particles Is not more than 6 mgKOH.

The acid value can be measured in the following manner. 1 g of the conductive particles was added to 36 g of acetone and dispersed by ultrasonic wave for 1 minute. Thereafter, phenolphthalein is used as an indicator and titrated with a 0.1 mol / L potassium hydroxide ethanol solution.

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 for 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 in 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. [ 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 the second conductive portion 33A and the 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. Therefore, 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. (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 soldering 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, a polyethylene terephthalate, a polysulfone, a polyphenylene oxide, a polyacetal, a polyimide, a polyamideimide, a polyetheretherketone, a polyether sulfone, a divinylbenzene polymer, 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 monomer that is incompatible with the monomer and a monomer that is crosslinkable.

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) (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, trimethoxysilyl (meth) acrylate, trimethylolpropane trimethoxysilane, triallyl trimellitate, divinyl benzene, diallyl phthalate, diallyl acrylamide, diallyl ether, And silane-containing monomers such as styrene and vinyltrimethoxysilane.

The above-mentioned resin particles can be obtained by polymerizing the above-mentioned polymerizable monomer having an ethylenic unsaturated group by a known method. This method includes, for example, suspension polymerization in the presence of a radical polymerization initiator and polymerization in which monomer is swollen together with the radical polymerization initiator using uncrosslinked seed particles.

When the base particles are inorganic particles other than metals or organic-inorganic hybrid particles, examples of inorganic materials 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 cross-linked polymer particles, and then firing as needed have. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

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, further 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 less than the above lower limit, the contact area between the conductive particles and the electrode is increased, so that the reliability of the conduction between the electrodes can be further improved, and the connection resistance between the electrodes connected via the conductive particles is further lowered . When the particle diameter of the base particles is less 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 further reduced.

The particle diameter of the base particles indicates the diameter when the base particles are spherical, and the maximum diameter when the 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 diameter of the base particles is within the range of 2 탆 or more and 5 탆 or less, the interval between the electrodes can be made smaller, and even if the thickness of the conductive part 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 of forming the conductive portion and the solder portion include a method of electroless plating, a method of electroplating, a method of physical impact, a method of mechanochemical reaction, a method of 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, a settler (manufactured by Tokushu Kousaku Co., Ltd.) or the like 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 lower 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. If the content of tin contained in the solder in the conductive particles is 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 is 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" manufactured by 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, so that the solder conducts between 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 an electrode. Tin-bismuth alloy, and tin-indium alloy.

The material constituting the solder (soldering portion) is preferably a consumable material (melting additive) having a liquidus line 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) process 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, More preferably greater than 500 ° C, and most preferably greater than 600 ° C. 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. Preferably, the conductive particles are used by melting the solder portion. It is preferable that the conductive particles are used without melting the solder portion and melting the second conductive portion. The melting point of the second conductive portion is higher than the melting point of the soldering portion so that 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 part 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 solder 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, so that the conductive particles are sufficiently deformed upon connection between the electrodes.

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. When the average particle diameter 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, and to easily arrange more solder in the conductive particles between the electrodes So that conduction reliability is further enhanced.

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 of any conductive particles with an electron microscope or an optical microscope and calculating an average value.

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 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. If the content of the conductive particles is lower than or equal to the lower limit and lower than or equal to the upper limit, it is possible to more effectively arrange the solder in the conductive particles on the electrode, and it is easy to arrange more 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 and an epoxy compound is more preferable from the viewpoint of further improving the curability and viscosity of the conductive material and further improving the connection reliability. The conductive material preferably includes an epoxy compound. The thermosetting compound may be used alone or in combination of two or more.

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. In the step of joining the members to be connected by using the above-described preferable epoxy compound, when the viscosity is high and acceleration is imparted by impact such as transportation, misalignment of the positions 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.

From the viewpoint of suppressing the occurrence of black soot, it is preferable that the conductive material includes a thermosetting compound having an isocyanurate skeleton as the thermosetting component and the thermosetting compound. From the viewpoint of enhancing the curability of the conductive material and improving the connection reliability, the thermosetting compound having an isocyanurate skeleton preferably has an epoxy group or a thiadiene group, and an epoxy compound having an isocyanurate skeleton or an epoxy compound having an isocyanurate skeleton It is preferably an episulfide compound. Epoxy compounds having an isocyanurate skeleton are particularly preferred. The conductive material may include a thermosetting compound having no isocyanurate skeleton.

Examples of the thermosetting compound having an isocyanurate skeleton include triazine triglycidyl ether and the like, and TEPIC series (TEPIC-G, TEPIC-S, TEPIC-SS, TEPIC-HP and TEPIC-L manufactured by Nissan Kagakugo Co., , TEPIC-PAS, TEPIC-VL, TEPIC-UC).

The episulfide compound having an isocyanurate skeleton is obtained, for example, by converting an epoxy group of an epoxy compound having an isocyanurate skeleton into a thiadiene group. This conversion method is known.

From the viewpoint of further suppressing the occurrence of black soot, the molecular weight of the thermosetting compound having an isocyanurate skeleton is preferably 200 or more, more preferably 300 or more, preferably 1000 or less, more preferably 600 Or less.

From the viewpoint of enhancing the curability of the conductive material and enhancing the connection reliability, the conductive material preferably contains, as the thermosetting component and the thermosetting compound, the thermosetting compound having the isocyanurate skeleton and the thermosetting compound having no isocyanurate skeleton . From the viewpoint of enhancing the curability of the conductive material and the heat resistance of the cured product and improving the connection reliability, the thermosetting compound having no isocyanurate skeleton preferably has an aromatic skeleton or an alicyclic skeleton, and does not have an isocyanurate skeleton, And is preferably a thermosetting compound having an aromatic skeleton or alicyclic skeleton.

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 displacement between the electrodes is further suppressed, Can be increased. From the viewpoint of further improving the impact resistance, the content of the above-mentioned thermosetting compound is preferably large. The content of the epoxy compound in 100 wt% of the conductive material is preferably 10 wt% or more, more preferably 15 wt% or more, and still more preferably 15 wt% or less, from the viewpoint of further improving the curability and viscosity of the conductive material and further improving the connection reliability. By weight or more, preferably 50% by weight or less, more preferably 30% by weight or less.

From the viewpoint of further suppressing black soot generation, the content of the thermosetting component having the isocyanurate skeleton in 100 wt% of the conductive material is preferably 5 wt% or more, more preferably 10 wt% or more , Preferably not more than 30 wt%, more preferably not more than 20 wt%.

From the viewpoint of further suppressing black soot generation, the content of the thermosetting compound having an isocyanurate skeleton in 100 wt% of the conductive material is preferably 5 wt% or more, more preferably 10 wt% or more , Preferably not more than 30 wt%, more preferably not more than 20 wt%.

The content of the thermosetting compound having no isocyanurate skeleton in 100% by weight of the conductive material is preferably 1% by weight or more, more preferably 2% by weight or less, %, Preferably not more than 20 wt%, more preferably not more than 15 wt%.

From the viewpoint of further suppressing the occurrence of black soot, the weight ratio of the content of the compound having an isocyanurate skeleton to the content of the flux (the content of the isocyanurate skeleton / the content of the flux) is preferably Is preferably 0.5 or more, more preferably 3 or more, preferably 20 or less, more preferably 15 or less, and may be 1 or less. In the case where the flux includes a flux having an isocyanurate skeleton, the content of the flux also includes the content of the flux having an isocyanurate skeleton.

From the viewpoint of further suppressing the occurrence of black soot, the weight ratio of the content of the thermosetting component having the isocyanurate skeleton to the content of the flux (the content of the thermosetting component having isocyanurate skeleton / the content of flux) Preferably 0.5 or more, more preferably 3 or more, preferably 20 or less, and more preferably 15 or less.

From the viewpoint of further suppressing the occurrence of black soot, the weight ratio of the content of the thermosetting compound having the isocyanurate skeleton to the content of the flux (the content of the thermosetting compound having an isocyanurate skeleton / the content of the flux) Preferably 0.5 or more, more preferably 3 or more, preferably 20 or less, more preferably 15 or less.

From the viewpoint of further suppressing the occurrence of black soot, the weight ratio of the content of the compound having an isocyanurate skeleton to the content of the conductive particles (the content of the isocyanurate skeleton-containing compound / the content of the conductive particles) Preferably 0.05 or more, more preferably 0.1 or more, preferably 0.5 or less, more preferably 0.4 or less.

The weight ratio of the content of the thermosetting component having the isocyanurate skeleton to the content of the conductive particles (the content of the thermosetting component having an isocyanurate skeleton / the content of the conductive particles) Is preferably 0.05 or more, more preferably 0.1 or more, preferably 0.5 or less, more preferably 0.4 or less.

The weight ratio of the content of the thermosetting compound having an isocyanurate skeleton to the content of the conductive particles (the content of the thermosetting compound having isocyanurate skeleton / the content of the conductive particles) Is preferably 0.05 or more, more preferably 0.1 or more, preferably 0.5 or less, more preferably 0.4 or less.

(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 further suppressing the occurrence of black soot, a thermosetting agent having a isocyanurate skeleton or a thiol curing agent is preferred. From the viewpoint of further suppressing the occurrence of black soot, a thermosetting agent having an isocyanurate skeleton is preferable, and a thiol curing agent is preferred. The conductive material may include a thermosetting agent having no isocyanurate skeleton.

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 examples thereof include 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 is 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 include an iodonium cation curing agent, an oxonium cation curing agent, and a sulfonium cation 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 azo compounds and organic peroxides. 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.

Examples of the thermosetting agent having an isocyanurate skeleton include tris- [(3-mercaptopropionyloxy) -ethyl] -isocyanurate and the like.

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. When the reaction initiation temperature of the thermosetting agent is lower than or equal to the lower limit and below the upper limit, 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, more preferably 10 deg. Is more preferable.

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

From the viewpoint of further suppressing the occurrence of black soot, the molecular weight of the thermosetting agent having an isocyanurate skeleton is preferably 200 or more, more preferably 300 or more, preferably 1000 or less, more preferably 600 Or less.

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, preferably 200 parts by weight or less, and even more preferably 100 parts by weight or less with respect to 100 parts by weight of the thermosetting compound 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, which has not been involved in curing after curing, is hardly left, and furthermore, the heat resistance of the cured product is further increased.

From the viewpoint of further suppressing black soot generation, the content of the thermosetting agent having an isocyanurate skeleton in 100 wt% of the conductive material is preferably 5 wt% or more, more preferably 10 wt% or more , Preferably not more than 30 wt%, more preferably not more than 20 wt%.

(Phosphoric acid compound)

From the viewpoint of more efficiently collecting the solder on the electrode, it is preferable that the conductive material includes a phosphoric acid compound. The phosphoric acid compound may be used alone or in combination of two or more.

From the viewpoint of more efficiently collecting the solder on the electrode, the phosphoric acid compound is preferably a phosphorous acid or a phosphorous acid ester, more preferably a phosphorous acid ester, and the phosphorous acid ester is a phosphorous acid ester represented by the following formula (11) desirable.

In the formula (11), R is preferably an organic group having a carbon number of 1 or more and 15 or less, and more preferably an organic group having a carbon number of 6 or more and 15 or less.

The phosphoric acid compound preferably has at least one organic group having 6 or more and 15 or less carbon atoms, more preferably 1 or more hydrocarbon groups having 6 or more carbon atoms and 15 or less carbon atoms, and an aryl group having 6 or more carbon atoms and 15 or less at 1 Is particularly preferable. The phosphoric acid compound may have two of these groups. Particularly preferred is a phosphorous acid having at least one aryl group, more preferably a phosphorous acid having two aryl groups, more preferably diphenylphosphoric acid or dibenzylphosphoric acid. The phosphorous acid having two aryl groups may have one phenyl group, two phenyl groups, one benzyl group, or two benzyl groups.

The pH of an aqueous solution obtained by dissolving 1 g of the phosphate compound in 10 g of water is measured. The pH of the aqueous solution is preferably 3.5 or more, more preferably 3.7 or more, further preferably 5 or more, and preferably 6 or less. The pH of the aqueous solution may be 5 or less. When the pH of the aqueous solution is not less than the lower limit and not more than the upper limit, the solder more efficiently collects on the electrode. The pH of the aqueous solution may be more than 3, more than 4, more than 5, or not less than 7.

The pH of the aqueous solution can be measured using a pH meter (" D-72 " manufactured by HORIBA) and an electrode ToupH electrode 9615-10D.

From the viewpoint of more efficiently collecting the solder on the electrode, it is preferable that the phosphorous acid ester is a phosphorous acid monoester or a dibasic acid diester. From the viewpoint of more efficiently collecting the solder on the electrode, it is preferable that the phosphoric acid compound does not have a (meth) acryloyl group and is not a (meth) acrylate compound.

The phosphoric acid compound may be a phosphoric acid or a reaction product of a phosphoric acid compound and an imidazole compound.

 The content of the phosphate compound in the conductive material is preferably 0.1% by weight or more, more preferably 1% by weight or more, and still more preferably 1% by weight or more, from the viewpoint of more efficiently arranging the solder on the electrode and further enhancing the conduction reliability. By weight, preferably not more than 15% by weight, more preferably not more than 10% by weight.

(Flux)

The conductive material includes a flux. By using the flux, the solder can be arranged more effectively on the electrode. When the solder is subjected to the flux action by the flux, black soot is likely to occur. However, in the present invention, since a compound having an isocyanurate skeleton is used, generation of black soot can be suppressed. The flux is not particularly limited. As the flux, a flux generally used for solder bonding 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 or a transfer paper. The flux may be an organic acid having two or more carboxyl groups, or may be fed. The use of an organic acid having two or more carboxyl groups and a papermaking layer further improves the conductivity reliability between the electrodes.

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 conduction reliability between the electrodes is further increased.

From the viewpoint of further suppressing black soot generation, a flux having an isocyanurate skeleton is preferable. The conductive material may include a flux not having an isocyanurate skeleton.

Examples of the flux having the isocyanurate skeleton include a compound having a carboxyl group and an isocyanurate skeleton. Examples of commercial products of the flux having the isocyanurate skeleton include CIC acid and MACIC-1 (manufactured by Shikoku Kasei Kogyo Co., Ltd.). The conductive material may include a flux not having an isocyanurate skeleton.

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, further preferably 150 ° C or lower, further 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 higher and 190 ° C or lower. It is particularly preferable that the activation temperature (melting point) of the flux is 80 캜 or more and 140 캜 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 (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 higher, more preferably 10 ° C or higher Do.

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, and still more preferably 10 ° C or higher.

The flux may be dispersed in the conductive material or attached to 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, since the temperature of the electrode portion first reaches the melting point (active temperature) of the flux, the oxide film on the surface of the solder in the conductive particles reaching the electrode preferentially is removed first, The solder can be spread on the surface of the electrode by neutralizing the charge on the surface of the solder. As a result, the solder can be agglomerated efficiently on the electrode.

The flux is preferably a flux that releases cations by heating. The solder can be disposed on the electrode more efficiently by using the flux that releases the positive ions by heating.

As the flux that releases the cation by the heating, the thermal cationic initiator may be mentioned.

From the viewpoint of further suppressing black soot generation, the molecular weight of the flux having the isocyanurate skeleton is preferably 200 or more, more preferably 300 or more, preferably 1000 or less, more preferably 600 or less to be.

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. 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.

From the viewpoint of further suppressing the occurrence of black soot, the content of the flux having the isocyanurate skeleton in 100 wt% of the conductive material is preferably 5 wt% or more, more preferably 10 wt% or more, Preferably 30% by weight or less, more preferably 20% by weight or less.

(Other components)

The conductive material may contain various additives such as fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, lubricants, antistatic agents and flame retardants .

(Connection structure and manufacturing method of connection structure)

A connection structure according to the present invention includes 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 connecting portion is the above-described conductive material, and the connecting portion is a cured product of 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 manufacturing method of the connection structure includes the steps of disposing the conductive material on a surface of a first connection target member having at least one first electrode on a surface thereof using the conductive material described above, A step of disposing a second connection target member having at least one second electrode on a surface thereof on a surface opposite to the connection target member side so that the first electrode and the second electrode face each other, The connecting member connecting the first connection target member and the second connection target member is formed by the conductive material and the first connection target member and the second connection target member are connected to each other by heating the conductive material at a temperature equal to or higher than the melting point of the solder, And electrically connecting the second electrode with the solder portion in the connection 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, solder in a plurality of conductive particles is likely to gather between the first electrode and the second electrode, ). ≪ / RTI > 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 transverse direction which should not be connected, and the insulation reliability can be improved.

Further, 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, it is preferable to use a conductive paste instead of a conductive film .

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 area of the solder wetting on the surface of the electrode is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, and preferably 100% or more Is less than 100%.

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 In the step of disposing the second connection target member and the step of forming the connecting portion, the conductive material is not subjected to a pressing force exceeding the force of the weight of the second connection object member . In these cases, the uniformity of the amount of solder can be further increased in a plurality of solder portions. In addition, the thickness of the solder portion can be made even thicker, and the solder in the plurality of conductive particles can be easily gathered between the electrodes, so that the solder in the plurality of conductive particles can be formed more efficiently Can be deployed. In addition, a part of the solder in the plurality of conductive particles is hardly arranged in a region (space) where no electrode is formed, 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. In addition, electrical connection between adjacent electrodes in the transverse direction which should not be connected can be further prevented, and the insulation reliability can be further enhanced.

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 applied to the conductive material without applying pressure, The solder disposed in the region (space) where the first electrode and the second electrode are 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 also found out that I could. In the present invention, a configuration in which a conductive paste is used 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 is employed in combination, It is meaningful to get the effect of a higher level.

Further, in WO 2008/023452 A1, it is described that the solder powder should be pressed at a predetermined pressure at the time of bonding in order to flow the solder powder efficiently on the electrode surface, 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 causes It is described that a predetermined pressure may be applied. In WO 2008/023452 A1, it is described that the pressure to be intentionally applied to the adhesive tape may be 0 MPa, but there is no description about the difference in the effect when the pressure exceeding 0 MPa is applied and the case where the pressure is 0 MPa. Further, in WO 2008/023452 A1, the importance of using paste pastes instead of films is not recognized at all.

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, so that 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.

1 includes a first connection target member 2, a second connection target member 3, a first connection target member 2 and a second connection target member 3, And a connecting portion 4 connected thereto. The connecting portion 4 is formed of the above-described conductive material. In the present embodiment, the conductive material includes solder particles as conductive particles.

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. There is no solder in the region (cured portion 4B) different from the soldering portion 4A gathered between the first electrode 2a and the second electrode 3a in the connecting portion 4 . There is no solder spaced apart from the soldering portion 4A in the region different from the soldering portion 4A (portion of the cured portion 4B). In the case of 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, Melts on the surface of the electrode and then solidifies to form the soldering portion 4A. This increases the connection area between the solder portion 4A and the first electrode 2a and between the solder portion 4A and the second electrode 3a. 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. As a result, conduction reliability and connection reliability in the connection structure 1 are enhanced.

Further, by heating, the flux generally gradually deactivates.

In the connection structure 1 shown in Fig. 1, all of the soldering portions 4A are located in areas facing each other between the first and second electrodes 2a, 3a. 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 . Further, in the present embodiment, the amount of solder spaced 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.

It is preferable that the first electrode and the second electrode are arranged such that when the first electrode and the second electrode are opposed to each other in the stacking direction of the first electrode and the connection portion and the second electrode, (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 area of mutually opposing portions of the second electrode , And a solder portion in the connection portion is preferably disposed.

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 11 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 on the region (space) where the first electrode 2a is not formed.

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. Next, as shown in Fig. 2 (b), the conductive material 11 on the surface of the first connection target member 2 is bonded to the side of the first connection target member 2 of the conductive material 11 The second connection target member 3 is disposed on the surface on the opposite side (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.

Next, 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 above the curing temperature of the thermosetting component 11B (binder). During this heating, the solder particles 11A existing in the regions where the electrodes are not formed are gathered between the first electrodes 2a and the second electrodes 3a (magnetic cohesion effect). When conductive paste is used instead of a conductive film, solder particles 11A effectively gather 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 connecting portion 4 connecting the first connection target member 2 and the second connection target member 3 is formed by the conductive material 11 do. 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, .

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 applied to the conductive material 11. As a result, 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. In addition, 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 to gather between the first electrode and the second electrode is hindered.

In addition, in the present embodiment, since the pressing is not performed, when the second connection target member is overlapped with the first connection target member coated with the conductive material, the electrode of the first connection target member and the electrode 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). 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 made of solder between the electrode of the first connection target member and the electrode of the second connection target member, This is because the minimum contact area of the other components is energetically stable, so that a connecting structure that is the minimum connection area structure is formed. At this time, it is preferable that the conductive material is not cured, and the viscosity of the components other than the conductive particles of the conductive material is sufficiently low at the temperature and time.

In this manner, 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 ° C or higher, more preferably 160 ° C or higher, preferably 450 ° C or lower, more preferably 250 ° C or lower, still more preferably 200 ° C or lower .

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 equal to or higher than the melting point of the solder and the curing temperature of the thermosetting component, And then heating the mixture.

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 the conductive film is used for connecting the connection target member, the solder tends to be difficult to collect on the electrode. 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 by using the conductive paste, 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 is further improved by not performing the pressing compared with the case of using other members to be connected such as a semiconductor chip .

The shape of the member to be connected includes a periphery, an area array, and the like. As a feature of each member, in the peripheral substrate, the electrode exists only on the outer peripheral portion of the substrate. In the area array substrate, electrodes are present on the surface.

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 connection target member 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.

The shape of the member to be connected includes a periphery, an area array, or the like. As a feature of each member, in the peripheral substrate, the electrode exists only on the outer peripheral portion of the substrate. In the area array substrate, electrodes are present on the surface.

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.

Thermosetting compound:

&Quot; YL980 " manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin

TEPIC-PAS " manufactured by Nissan Kagakugo Co., Ltd., epoxy compound having an isocyanurate skeleton

Modified product of TEPIC-PAS: A compound (synthetic product) obtained by converting epoxy group into thiadiene of "TEPIC" manufactured by Nissan Kagakugo Co., Ltd., episulfide compound having isocyanurate skeleton

"TEPIC-VL" manufactured by Nissan Kagakugo Co., Ltd.

TEPIC-UC manufactured by Nissan Kagakugo Co., Ltd.

Thermal curing agent:

&Quot; HXA3922HP " manufactured by Asahi Kasei Immeltiles Co.,

Quot; TEMPIC " manufactured by SC Yuki Kagaku Co.,

Curing accelerator:

2MA-OK " manufactured by Shikoku Kasei Kogyo Co., Ltd., imidazole hardening accelerator

Phosphoric acid compound:

'S hoku Kagaku Kogyo Preparation "JP260", diphenyl hydrogen _{phosphite, (C 6 H 5 -O-)} 2 P (= O) H

Flux:

Glutaric acid

"CIC" manufactured by Shikoku Kasei Corporation

MACIC-1 " manufactured by Shikoku Kasei Corporation

Conductive particles:

SnBi solder particles (average particle diameter 30 占 퐉), Sn42Bi58

(Examples 1 to 11 and Comparative Example 1)

(1) Fabrication of anisotropic conductive paste

The components shown in the following Tables 1 and 2 were compounded in amounts shown in Tables 1 and 2 below to obtain an anisotropic conductive paste.

(2) Fabrication of first connection structure (area array substrate)

As the first connection target member, copper electrodes of 250 占 퐉 at a pitch of 400 占 퐉 are arranged on the surface of the semiconductor chip body (size 5 占 5mm, thickness 0.4mm) in an area array, and a passivation film A thickness of 5 mu m, and an opening diameter of the electrode portion of 200 mu m) were formed. The total number of copper electrodes is 10 x 10 per 100 semiconductor chips.

As the second connection target member, a copper electrode was arranged on the surface of the glass epoxy substrate main body (size 20 x 20 mm, thickness 1.2 mm, material FR-4) so as to have the same pattern as the electrode of the first connection object member And a solder resist film was formed on a region where the copper electrode was not disposed. The step difference between the surface of the copper electrode and the surface of the solder resist film is 15 mu m, and the solder resist film protrudes from the copper electrode.

An anisotropic conductive paste immediately after fabrication was coated on the upper surface of the glass epoxy substrate so as to have a thickness of 100 m to form an anisotropic conductive paste layer. Subsequently, the semiconductor chips were stacked on the upper surface of the anisotropic conductive paste layer so that the electrodes were opposed to each other. The weight of the semiconductor chip is applied to the anisotropic conductive paste layer. From this state, the temperature of the anisotropic conductive paste layer was heated to 139 占 폚 (melting point of solder) after 5 seconds from the start of raising the temperature. Further, after 15 seconds from the start of the temperature rise, the anisotropic conductive paste layer was heated so that the temperature of the anisotropic conductive paste layer became 160 占 폚 to cure the anisotropic conductive paste to obtain a connection structure. At the time of heating, no pressure was applied.

(3) Fabrication of second connection structure (peripheral substrate)

As the first connection target member, a copper electrode having a thickness of 400 占 퐉 and a thickness of 250 占 퐉 is disposed (peripheral) on the periphery of the chip on the surface of the semiconductor chip body (size 5 占 5mm, thickness 0.4mm) A semiconductor chip in which a film (polyimide, thickness: 5 mu m, opening diameter of electrode portion: 200 mu m) was prepared. The number of copper electrodes is 36 in total of 10 x 4 sides per semiconductor chip.

As the second connection target member, a copper electrode was arranged on the surface of the glass epoxy substrate main body (size 20 x 20 mm, thickness 1.2 mm, material FR-4) so as to have the same pattern as the electrode of the first connection object member And the step difference between the surface of the copper electrode where the solder resist film is formed in the region where the copper electrode is not disposed and the surface of the solder resist film is 15 mu m and the solder resist film protrudes more than the copper electrode.

An anisotropic conductive paste immediately after fabrication was applied to the peripheral portion of the upper surface of the glass epoxy substrate so as to have a thickness of 100 m to form an anisotropic conductive paste layer. Subsequently, the semiconductor chips were stacked on the upper surface of the anisotropic conductive paste layer so that the electrodes were opposed to each other. The weight of the semiconductor chip is applied to the anisotropic conductive paste layer. From this state, the temperature of the anisotropic conductive paste layer was heated to 139 占 폚 (melting point of solder) after 5 seconds from the start of raising the temperature. Further, after 15 seconds from the start of the temperature rise, the anisotropic conductive paste layer was heated so that the temperature of the anisotropic conductive paste layer became 160 占 폚 to cure the anisotropic conductive paste to obtain a connection structure. At the time of heating, no pressure was applied.

(evaluation)

(1) Viscosity

The viscosity (ηmp) of the solder in the conductive particles of the anisotropic conductive paste at the melting point of C was measured with a strain control 1rad, 20 [deg.] C / min and a measurement temperature range of 40 to 200 [deg.] C.

(2) occurrence of black soot

Whether or not black soot derived from the solder was contained in the connection portions (hardened portions) of the obtained first and second connection structures was evaluated. The generation of black soot was judged by the following criteria.

[Criteria for black soot]

○○○: No occurrence of black soot, nor a thin spot

○○: There is no black soot, and there are some areas that are lightly tinted.

○: Black soot occurs very little (does not affect connection resistance)

△: Black soot occurs a little (it has a little influence on connection resistance)

×: black soot occurs (enough to affect connection resistance)

(3) Arrangement accuracy of the solder on the electrode

In the obtained first and second connection structures, when the portions of the first electrode and the second electrode facing each other in the stacking direction of the first electrode, the connection portion, and the second electrode are viewed, The ratio X of the area where the solder portion is arranged in the connection portion in the area 100% of the facing portion was evaluated. The placement accuracy of the solder on the electrode was evaluated based on the following criteria.

[Judgment Criteria of Arrangement Accuracy of Solder on Electrode]

X: At least 95% of ratio X

○○: ratio X is 90% or more and less than 95%

?: The ratio X is 80% or more and less than 90%

DELTA: ratio X is 60% or more and less than 80%

X: ratio X is less than 60%

(4) Reliability of conduction between the upper and lower electrodes

In the obtained first and second connection structures (n = 15), the connection resistances between the upper and lower electrodes were measured by the four-terminal method, respectively. 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 8.0Ω or less

○: Average value of connection resistance is more than 8.0Ω, 10.0Ω or less

?: Average value of connection resistance exceeding 10.0?, Not exceeding 15.0?

X: Average value of connection resistance exceeds 15.0?

(5) Insulation reliability between adjacent electrodes

In the obtained first and second connection structures (n = 15), after being left for 100 hours in an atmosphere at a temperature of 85 캜 and a humidity of 85%, 5 V was applied between adjacent electrodes and the resistance value was measured at 25 points Respectively. The insulation reliability was judged based on the following criteria.

[Judgment Criteria of Insulation Reliability]

○○: Average value of connection resistance is more than 10 ⁷ Ω

○: Average value of connection resistance is 10 ⁶ Ω or more, less than 10 ⁷ Ω

?: Average value of connection resistance is 10 ⁵ ? Or more, less than 10 ⁶ ?

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

The results are shown in Tables 1 and 2 below.

Similar tendencies were also observed when a flexible printed circuit board, a resin film, a flexible flat cable and a rigid flexible substrate were used.

1, 1X: connection structure
2: first connection object member
2a: first electrode
3: second connection object member
3a: second electrode
4, 4X: connection
4A, 4XA: soldering portion
4B and 4XB:
11: Conductive material
11A: Solder particles (conductive particles)
11B: Thermosetting component
21: Conductive particles (solder particles)
31: conductive particles
32: Base particles
33: conductive part (conductive part having solder)
33A: second conductive part
33B: soldering portion
41: conductive particles
42: soldering portion

Claims (14)

A plurality of conductive particles having a solder, a thermosetting component, and a flux on the outer surface portion of the conductive portion,
As the thermosetting component or the flux, a compound having an isocyanurate skeleton,
Wherein a viscosity of the conductive material at the melting point of the solder in the conductive particle is not less than 0.1 Pa · s and not more than 20 Pa · s. The conductive material according to claim 1, wherein the weight ratio of the content of the compound having an isocyanurate skeleton to the content of the flux is 0.5 or more and 20 or less. 3. The conductive material according to claim 1 or 2, wherein the weight ratio of the content of the compound having an isocyanurate skeleton to the content of the conductive particles is 0.05 or more and 0.5 or less. The conductive material according to any one of claims 1 to 3, wherein the molecular weight of the compound having an isocyanurate skeleton is 200 or more and 1000 or less. 5. The conductive material according to any one of claims 1 to 4, which comprises, as the thermosetting component, a thermosetting compound having an isocyanurate skeleton or a thermosetting agent having an isocyanurate skeleton. 6. The conductive material of claim 5, wherein the thermosetting component comprises a thermosetting compound having an isocyanurate skeleton. 7. The conductive material according to any one of claims 1 to 6, wherein the thermosetting component comprises a thermosetting compound having no isocyanurate skeleton. 8. The conductive material according to claim 7, wherein the thermosetting component comprises a thermosetting compound having an isocyanurate skeleton and a thermosetting compound having no isocyanurate skeleton. The conductive material according to claim 7 or 8, wherein the thermosetting compound having no isocyanurate skeleton is a thermosetting compound having no isocyanurate skeleton and having an aromatic skeleton or alicyclic skeleton. 10. The conductive material according to any one of claims 1 to 9, comprising a phosphate compound. 11. The conductive material according to any one of claims 1 to 10, wherein the conductive particles are solder particles. 12. The conductive material according to any one of claims 1 to 11, which is liquid at 25 占 폚 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,
The connecting part is a cured product of the conductive material according to any one of claims 1 to 12,
And the first electrode and the second electrode are electrically connected to each other by the solder portion in the connection portion. 14. The method of claim 13, 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 at least 50% of an area of 100% of the mutually facing portions of the connecting portion is provided with a solder portion in the connecting portion.

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