TWI704581B - Conductive material and connection structure - Google Patents

Abstract

The present invention provides a conductive material capable of selectively disposing solder in conductive particles on an electrode to improve conduction reliability. The conductive material of the present invention contains a plurality of conductive particles having solder on the outer surface of the conductive part and a thermosetting component, and the conductive particles and the above-mentioned conductive particles are heated at a temperature increase rate of 10°C/min from 25°C. When performing differential scanning calorimetry for thermosetting components, the temperature region showing the endothermic peak derived from the melting of the solder in the conductive particles and the temperature region showing the exothermic peak derived from the hardening of the thermosetting component overlap at least in part .

Description

Conductive material and connection structure

The present invention relates to a conductive material containing conductive particles with solder. In addition, the present invention relates to a connection structure using the above-mentioned conductive material.

Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film have been widely known. In the anisotropic conductive material described above, conductive particles are dispersed in the adhesive.

In order to obtain various connection structures, the above-mentioned anisotropic conductive materials are used for, for example, the connection between flexible printed substrates and glass substrates (FOG (Film on Glass)), and the connection between semiconductor chips and flexible printed substrates (COF (Chip on Film), the connection between the semiconductor chip and the glass substrate (COG (Chip on Glass, chip on glass)), and the connection between the flexible printed substrate and the epoxy glass substrate (FOB (Film on Board, coated board) )Wait.

When electrically connecting the electrode of the flexible printed circuit board and the electrode of the glass epoxy substrate using the above-mentioned anisotropic conductive material, the anisotropic conductive material containing conductive particles is arranged on the glass epoxy substrate. Then, the flexible printed circuit board is laminated and heated and pressurized. Thereby, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connected structure.

As an example of the anisotropic conductive material described above, Patent Document 1 below describes an anisotropic conductive material containing conductive particles and a resin component that has not finished curing at the melting point of the conductive particles. Specific examples of the above-mentioned conductive particles include tin (Sn), indium (In), bismuth (Bi), silver (Ag), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd) ), gallium (Ga) and thallium (Tl) and other metals, Or an alloy of these metals.

In Patent Document 1, it is described that the electrodes are electrically connected through the following steps: a resin heating step of heating an anisotropic conductive resin to a temperature higher than the melting point of the conductive particles and the temperature at which the resin component has not finished curing ; The resin component hardening step of hardening the above-mentioned resin component. In addition, it is described in Patent Document 1 that the mounting is performed under the temperature distribution shown in FIG. 8 of Patent Document 1. In Patent Document 1, the conductive particles are melted in a resin component that has not finished curing at the temperature at which the anisotropic conductive resin is heated.

Patent Document 2 described below discloses an adhesive tape that includes a resin layer containing a thermosetting resin, solder powder, and a hardening agent, and the solder powder and the hardening agent are present in the resin layer. The adhesive tape is film-like rather than pasty.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2004-260131

[Patent Document 2] WO2008/023452A1

In the conventional anisotropic conductive material containing solder powder or conductive particles with a solder layer on the surface, there are cases where the solder powder or conductive particles are not efficiently arranged on the electrode (wire).

In addition, if 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 containing solder may not be efficiently arranged on the electrodes ( Online). In addition, in the example of Patent Document 1, in order to make the solder sufficiently move at a temperature above the melting point of the solder, the temperature is maintained to connect the structure The manufacturing efficiency becomes low. If the installation is performed under the temperature distribution shown in FIG. 8 of Patent Document 1, the manufacturing efficiency of the connection structure becomes low.

In addition, the adhesive tape described in Patent Document 2 has a film shape rather than a paste shape. In the adhesive tape having the composition described in Patent Document 2, it is difficult to efficiently arrange the solder powder on the electrode (wire). For example, in the adhesive tape described in Patent Document 2, it is easy to arrange a part of the solder powder in the region (space) where the electrode is not formed. The solder powder arranged in the area where the electrode is not formed does not contribute to the conduction between the electrodes.

The object of the present invention is to provide a conductive material capable of selectively disposing solder in conductive particles on electrodes to improve the reliability of conduction. Furthermore, an object of the present invention is to provide a connection structure using the above-mentioned conductive material.

According to a broad aspect of the present invention, there is provided a conductive material, which contains a plurality of conductive particles with solder on the outer surface of the conductive part, and a thermosetting component, and the temperature is 10°C/min from 25°C. When performing differential scanning calorimetry by heating the conductive particles and the thermosetting component at the heating rate, the temperature range showing the endothermic peak derived from the melting of the solder in the conductive particles and the temperature region showing the endothermic peak derived from the thermosetting component The temperature region of the exothermic peak of hardening is at least partially repeated.

In a specific aspect of the electrically conductive material of the present invention, the total exothermic heat derived from the hardening of the thermosetting component in the temperature range below the endothermic peak temperature of the melting of the solder in the conductive particles is smaller than the source The total exothermic heat derived from the hardening of the thermosetting component in the temperature region above the endothermic peak top temperature of the melting of the solder in the above-mentioned conductive particles.

In a specific aspect of the conductive material of the present invention, there is a hardening derived from the thermosetting component at a lower temperature than the endothermic peak temperature derived from the melting of the solder in the conductive particle The first exothermic peak temperature is higher than the endothermic peak temperature derived from the melting of the solder in the conductive particles, and there is a second exothermic peak temperature derived from the hardening of the thermosetting component.

In a specific aspect of the conductive material of the present invention, the absolute value of the difference between the endothermic peak top temperature and the first exothermic peak top temperature is 3°C or more and 60°C or less, and the endothermic peak top temperature is the same as the second exothermic peak temperature. The absolute value of the difference in exothermic peak top temperature is 5°C or more and 60°C or less.

In a specific aspect of the conductive material of the present invention, the end temperature of the peak on the high temperature side of the endothermic peak is lower than the end temperature of the peak on the high temperature side of the exothermic peak on the highest temperature side.

In a specific aspect of the conductive material of the present invention, the end temperature of the peak on the high temperature side of the endothermic peak is lower than the end temperature of the peak on the high temperature side of the exothermic peak on the highest temperature side, and the peak start temperature on the low temperature side of the endothermic peak is higher The peak starting temperature on the low temperature side of the above exothermic peak on the lowest temperature side.

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

In a specific aspect of the conductive material of the present invention, carboxyl groups are present on the outer surface of the conductive particles.

In a specific aspect of the conductive material of the present invention, the conductive material is liquid and conductive paste at 25°C.

According to a broad aspect of the present invention, there is provided a connection structure including a first connection object member having at least one first electrode on the surface, a second connection object member having at least one second electrode on the surface, and the first A connection part where the connection object member and the second connection object member are connected, and the connection part is a cured product of the conductive material, and the first electrode and the second electrode are electrically connected by the solder part in the connection part.

In a specific aspect of the connection structure of the present invention, it is preferable to observe the opposing relationship between the first electrode and the second electrode in the direction in which the first electrode, the connecting portion, and the second electrode are stacked. Part, on the opposite side of the first electrode and the second electrode More than 50% of the product 100% is configured with the solder part in the above-mentioned connection part.

Since the conductive material of the present invention contains a plurality of conductive particles having solder on the outer surface of the conductive part, and a thermosetting component, the conductive particles and the heat-curing components are heated at a heating rate of 10°C/min from 25°C. When the thermosetting component is subjected to differential scanning calorimetry, at least a part of the temperature region showing the endothermic peak derived from the melting of the solder in the conductive particles and the temperature region showing the exothermic peak derived from the hardening of the thermosetting component Repeating, therefore, the solder in the conductive particles can be selectively arranged on the electrode, and the conduction reliability can be improved.

1: Connection structure

1X: Connection structure

2: The first connection object component

2a: first electrode

3: The second connection object component

3a: second electrode

4: Connection part

4A: Solder part

4B: Hardened part

4X: Connection part

4XA: Solder Department

4XB: Hardened part

11: conductive material

11A: Solder particles (conductive particles)

11B: Thermosetting component

21: Conductive particles (solder particles)

31: Conductive particles

32: Substrate particles

33: Conductive part (conductive part with solder)

33A: The second conductive part

33B: Solder section

41: conductive particles

42: Solder Department

FIG. 1 is a schematic diagram showing an example of the relationship between the endothermic peak derived from the melting of solder in conductive particles and the exothermic peak derived from the hardening of the thermosetting component in differential scanning calorimetry.

Fig. 2 is a cross-sectional view schematically showing a connection structure obtained by using a conductive material according to an embodiment of the present invention.

3(a) to (c) are cross-sectional views for explaining each step of an example of a method of manufacturing a connection structure using a conductive material according to an embodiment of the present invention.

Fig. 4 is a cross-sectional view showing a modification of the connection structure.

Fig. 5 is a cross-sectional view showing a first example of conductive particles that can be used for conductive materials.

Fig. 6 is a cross-sectional view showing a second example of conductive particles that can be used for conductive materials.

Fig. 7 is a cross-sectional view showing a third example of conductive particles that can be used for conductive materials.

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

(Conductive material)

The conductive material of the present invention contains a plurality of conductive particles and a binder. The above conductive particles With conductive parts. The said electroconductive particle has solder on the outer surface part of a conductive part. The solder is contained in the conductive part and is part or all of the conductive part.

The conductive material of the present invention contains a thermosetting component as the above-mentioned binder. The said thermosetting component preferably contains a thermosetting compound and a thermosetting agent.

In the present invention, when heating is performed at a temperature increase rate of 10°C/min from 25°C and differential scanning calorimetry is performed, the temperature range and the source of the endothermic peak derived from the melting of the solder in the conductive particles are shown At least a part of the temperature region from the exothermic peak of the curing of the thermosetting component is repeated.

Specifically, the above-mentioned thermosetting component is heated at a temperature increase rate of 10°C/min, and differential scanning calorimetry (DSC) is performed. In addition, the conductive particles were heated at a temperature increase rate of 10°C/min, and differential scanning calorimetry (DSC) was performed. The measurement can be performed using conductive materials. As shown schematically in Figure 1, in the DSC, in the conductive material of the present invention, the temperature range of the endothermic peak P3 derived from the melting of the solder in the conductive particles is shown to be derived from the heat The temperature region of the exothermic peaks P1 and P2 of hardening of the hardening component overlaps at least partially.

In the present invention, since the above-mentioned structure is provided, the solder in the conductive particles can be selectively arranged on the electrode. When the electrodes are electrically connected, the solder in the conductive particles tends to gather between the electrodes facing up and down, and the solder in the conductive particles can be efficiently arranged on the electrodes (wires). In addition, it becomes less likely that the cured product of the thermosetting component remains between the electrode and the solder portion, and the contact area between the electrode and the solder portion can be increased.

In addition, it is difficult to arrange a part of the solder in the conductive particles in the area (space) where the electrode is not formed, and the amount of the solder to be arranged in the area where the electrode is not formed can be very small. In the present invention, the solder not located between the facing electrodes can be efficiently moved between the facing electrodes. Therefore, the reliability of conduction between the electrodes can be improved. And it can prevent the electrical connection between the laterally adjacent electrodes that cannot be connected, and can improve the insulation reliability.

As shown in Fig. 1, it is preferable that the total exothermic amount of heat derived from the hardening of the thermosetting component in the temperature range below the P3t temperature of the endothermic peak of the melting of the solder in the conductive particles (1) is less than the source The total exothermic amount of heat derived from the hardening of the thermosetting component in the temperature range above the P3t temperature of the endothermic peak top of the melting of the solder in the above-mentioned conductive particles (2). The total heat release (1) is preferably 1/2 or less of the total heat release (2), more preferably 1/5 or less. Since the total amount of heat (1) is relatively small, the thickness of the conductive material can be sufficiently ensured before the solder is melted, and the positions of the conductive particles can be brought close. As a result, the conductive particles can be further moved to the electrode. Especially when mounting semiconductor chips on the surface, since the resin flows from the center to the outer periphery, the amount of solder on the electrodes at the center and the outer periphery is likely to be different. The total amount of heat released by the hardening of the hardening component is adjusted to the above range, so that the amount of solder on the center and outer periphery of the electrode can be installed uniformly, and the unevenness of the amount of solder on the electrode can be effectively suppressed. Due to the relatively large total heat release (2), after the solder is melted, the solder disposed on the electrode can stay on the electrode, thereby further increasing the amount of solder on the electrode.

As shown in Fig. 1, it is preferable that the first exothermic peak P1t temperature derived from the hardening of the thermosetting component is present at a lower temperature than the endothermic peak top P3t temperature derived from the melting of the solder in the conductive particles. In addition, there is a second exothermic peak P2t temperature derived from the hardening of the thermosetting component on the higher temperature side than the endothermic peak top P3t temperature derived from the melting of the solder in the conductive particles. In this case, the positions of a plurality of conductive particles can be brought close. As the positions of the plurality of conductive particles are close, the solder will melt rapidly, and as a result, the plurality of conductive particles can be moved further to the electrode.

The absolute value of the difference between the temperature of the endothermic peak top P3t and the temperature of the first exothermic peak top P1t is better It is 3°C or higher, more preferably 5°C or higher, still more preferably 8°C or higher, and preferably 60°C or lower, more preferably 58°C or lower, and still more preferably 55°C or lower. In this case, the positions of a plurality of conductive particles can be brought close. As the positions of the plurality of conductive particles are close, the solder will melt rapidly, and as a result, the plurality of conductive particles can be moved further to the electrode.

The absolute value of the difference between the temperature of the endothermic peak top P3t and the temperature of the second exothermic peak top P2t is preferably 5°C or higher, more preferably 8°C or higher, still more preferably 10°C or higher, and preferably 60°C or lower, It is more preferably 58°C or lower, and still more preferably 55°C or lower. In this case, after disposing the molten solder on the electrode, the solder can stay on the electrode, which further increases the amount of solder on the electrode.

From the viewpoint of disposing the solder on the electrode more efficiently, as shown in FIG. 1, it is preferable that the peak height of the exothermic peak at the temperature of the first exothermic peak P1t is smaller than that at the temperature of the second exothermic peak P2t. The peak height of the exothermic peak.

The temperature of the exothermic peak tops P1t and P2t and the temperature of the endothermic peak top P3t indicate the temperature at which the exothermic heat or endothermic heat of the exothermic peaks P1, P2 or the endothermic peak P3 becomes the highest. The so-called exothermic peaks P1 and P2 indicate the part where the exothermic heat starts to rise from the reference line B (the temperature in this part is the exothermic start temperature), and the exothermic heat decreases after reaching the exothermic peaks P1t and P2t, and the exothermic heat again The part that starts to increase or the heat release reaches the baseline B. The above-mentioned endothermic peak P3 represents the part where the endothermic heat starts to rise from the reference line B (the temperature in this part is the endothermic starting temperature), and the endothermic heat decreases after reaching the endothermic peak P3t, and the endothermic heat reaches the reference line B The part. In order to make the temperature of the exothermic peak top P1t and P2t and the temperature of the endothermic peak top P3t meet the above relationship, appropriately adjust the type of thermosetting compound in the thermosetting component, the type of thermosetting agent, and the solder in the conductive particles The composition and so on.

From the viewpoint of disposing the solder more efficiently on the electrode, it is preferable that the end temperature of the peak on the high-temperature side of the endothermic peak derived from the melting of the solder in the conductive particles be lower than that derived from the thermal hardening The end temperature of the peak at the high temperature side of the exothermic peak at the highest temperature side of the hardening of the chemical component. The end temperature of the peak on the high temperature side of the endothermic peak derived from the melting of the solder in the conductive particles is the temperature at which the endothermic peak P3 in FIG. 1 is connected to the reference line B on the high temperature side. The peak end temperature on the high temperature side of the exothermic peak on the highest temperature side of the hardening of the thermosetting component is the temperature at which the exothermic peak P2 in FIG. 1 is connected to the reference line B on the high temperature side.

From the viewpoint of disposing the solder more efficiently on the electrode, it is preferable that the peak start temperature on the low-temperature side of the endothermic peak derived from the melting of the solder in the conductive particles is higher than that derived from the thermosetting component. The peak starting temperature on the low temperature side of the exothermic peak on the lowest temperature side of hardening. The peak starting temperature on the low temperature side of the endothermic peak derived from the melting of the solder in the conductive particles is the temperature at which the endothermic peak P3 in FIG. 1 is connected to the reference line B on the low temperature side. The peak start temperature on the low temperature side of the exothermic peak on the lowest temperature side of the hardening of the above-mentioned thermosetting component is the temperature at which the exothermic peak P1 in FIG. 1 is connected to the reference line B on the low temperature side.

From the viewpoint of disposing the solder more efficiently on the electrode, and from the viewpoint of disposing the solder more efficiently on the electrode, the high temperature derived from the endothermic peak of the melting of the solder in the conductive particles is preferred The end temperature of the peak on the side is lower than the end temperature of the peak on the high temperature side of the exothermic peak on the highest temperature side of the hardening of the above-mentioned thermosetting component, and starts from the peak on the low temperature side of the endothermic peak of the melting of the solder in the conductive particles The onset temperature is higher than the peak onset temperature on the low temperature side of the exothermic peak on the lowest temperature side of the hardening of the above-mentioned thermosetting component.

In order to dispose the solder on the electrode more efficiently, the above-mentioned conductive material is preferably liquid at 25° C., and preferably a conductive paste.

In order to arrange the solder on the electrode more efficiently, the viscosity (η25) of the conductive material at 25°C is preferably 20Pa. s or more, more preferably 25Pa. s or more, and preferably 600Pa. s or less, more preferably 550Pa. s or less. The viscosity of the above conductive materials at 25°C will affect the conductive particles Or the initial movement speed of the solder conductive connection.

In order to arrange the solder on the electrode more efficiently, the viscosity (η25) of the conductive material at 25°C relative to the viscosity (η100) of the conductive material at 100°C is preferably 10 or more, more preferably 80 or more , And more preferably 100 or more, more preferably 2500 or less, more preferably 2000 or less. The viscosity of the above-mentioned conductive material at 100°C will affect the movement speed of the conductive particles or solder in the middle of the conductive connection. If the ratio (η25/η100) is greater than or equal to the above lower limit and less than or equal to the above upper limit, the conductive particles or solder will efficiently move from the initial stage to the middle stage during conductive connection.

The above-mentioned viscosity can be measured under the conditions of strain control 1rad, frequency 1Hz, heating rate 20°C/min, and measurement temperature range 25~200°C using STRESSTECH (manufactured by EOLOGICA), etc.

In addition, the viscosity of the conductive material after holding the conductive material for 10 seconds at the temperature of the exothermic peak P1t derived from the hardening of the thermosetting component is preferably 1 Pa. s or more, more preferably 3Pa. s or more, and preferably 10Pa. s or less, more preferably 8Pa. s or less. Furthermore, the viscosity of the conductive material after holding the conductive material for 10 seconds at the temperature of the exothermic peak P2t derived from the hardening of the thermosetting component is preferably 100 Pa. s or more, more preferably 110Pa. s or more, and preferably 10000Pa. s or less, more preferably 9500Pa. s or less.

The aforementioned conductive material can be used in the form of a conductive paste, a conductive film, and the like. The aforementioned conductive material is preferably an anisotropic conductive material. The aforementioned conductive paste is preferably an anisotropic conductive paste. The above-mentioned conductive film is preferably an anisotropic conductive film. The above-mentioned conductive materials can be preferably used for electrical connection of electrodes. The above-mentioned conductive material is preferably a circuit connection material.

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

(Conductive particles)

The said electroconductive particle electrically connects between electrodes of a connection object member. Above conductivity The particles have solder on the outer surface of the conductive part. The aforementioned conductive particles may be solder particles. The above-mentioned solder particles are formed of solder. The solder particles have solder on the outer surface portion of the conductive part. The solder particles are particles in which the center part and the outer surface part of the conductive part of the solder particles are both solder particles. Regarding the above-mentioned solder particles, the central part and the outer surface part of the conductive part are formed of solder. The said electroconductive particle may have a base particle and the electroconductive part arrange|positioned on the surface of this base particle. In this case, the conductive particles have solder on the outer surface of the conductive part.

Furthermore, compared with the case of using the above-mentioned solder particles, when using conductive particles having base particles not formed of solder and a solder portion arranged on the surface of the base particles, conductive particles become difficult Concentrated on the electrode, the solder bonding between the conductive particles is low. Therefore, the conductive particles moving on the electrode tend to easily move outside the electrode, and the effect of suppressing the displacement between the electrodes also tends to decrease. Therefore, the aforementioned conductive particles are preferably solder particles.

From the viewpoint of effectively reducing the connection resistance in the connection structure and effectively suppressing the generation of voids, it is preferable that a carboxyl group or an amine group is present on the outer surface of the conductive particles (outside the solder surface), and preferably there is The carboxyl group preferably has an amine group. Preferably, a carboxyl group or an amino group is covalently bonded to the outer surface of the conductive particle (outside the solder surface) via a Si-O bond, an ether bond, an ester bond or a group represented by the following formula (X) The group is more preferably a group containing a carboxyl group or an amino group which is covalently bonded to the outer surface of the conductive particle (outside the solder surface) via 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 addition, in the following formula (X), the right end part and the left end part represent bonding sites.

[化1]

There are hydroxyl groups on the surface of the solder. By covalently bonding the hydroxyl group and the carboxyl-containing group, it is possible to form a stronger bond than the bonding by other coordination bonds (chelation coordination), etc., so that the Conductive particles that connect resistance and can suppress the generation of pores.

In the above-mentioned conductive particles, the bonding form between the surface of the solder and the carboxyl group-containing group may not contain a coordinate bond or may not contain a bond formed by chelate coordination.

From the viewpoint of effectively reducing the connection resistance in the connection structure and effectively suppressing the generation of pores, the above-mentioned conductive particles are preferably used by using a compound having a functional group capable of reacting with a hydroxyl group and a carboxyl group or amino group (hereinafter Sometimes referred to as compound X), it is obtained by reacting the hydroxyl group on the solder surface with the above-mentioned functional group capable of reacting with the hydroxyl group. In the above reaction, a covalent bond is formed. By reacting the hydroxyl group on the surface of the solder with the above-mentioned functional group capable of reacting with the hydroxyl group in the above-mentioned compound, conductive particles with a carboxyl group or amino group-containing group covalently bonded to the surface of the solder can be easily obtained. Obtain conductive particles having a group containing a carboxyl group or an amino group covalently bonded to the surface of the solder via an ether bond or an ester bond. By reacting the hydroxyl group on the surface of the solder with the functional group capable of reacting with the hydroxyl group, the compound X can be chemically bonded to the surface of the solder in the form of a covalent bond.

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. Preferably, it is a hydroxyl group or a carboxyl group. The functional group capable of reacting with the hydroxyl group may be a hydroxyl group or a carboxyl group.

As a compound having a functional group capable of reacting with a hydroxyl group, acetyl propionic acid, pentane Diacid, glycolic acid, succinic acid, malic acid, oxalic acid, malonic acid, adipic acid, 5-ketohexanoic acid, 3-hydroxypropionic acid, 4-aminobutyric acid, 3-mercaptopropionic acid, 3-mercapto Isobutyric acid, 3-methylthiopropionic acid, 3-phenylpropionic acid, 3-phenylisobutyric acid, 4-phenylbutyric acid, capric acid, dodecanoic acid, tetradecanoic acid, pentadecane Acid, hexadecanoic acid, 9-hexadecenoic acid, heptadecanoic acid, stearic acid, oleic acid, isoleic acid, linoleic acid, (9,12,15)-linolenic acid, nineteen Alkanoic acid, arachidic acid, sebacic acid and dodecanedioic acid, etc. Preferably it is glutaric acid or glycolic acid. The compound having a functional group capable of reacting with a hydroxyl group may be used alone or in combination of two or more kinds. The compound having a functional group capable of reacting with a hydroxyl group is preferably a compound having at least one carboxyl group.

The above-mentioned compound X preferably has a soldering function, and the above-mentioned compound X preferably has a soldering function when bonded to the surface of the solder. The compound with the effect of soldering can remove the oxide film on the solder surface and the oxide film on the electrode surface. The carboxyl group has a fluxing effect.

Examples of compounds with fluxing effect include: acetylpropionic acid, glutaric acid, glycolic acid, succinic acid, 5-ketohexanoic acid, 3-hydroxypropionic acid, 4-aminobutyric acid, 3-mercaptopropionic acid , 3-mercaptoisobutyric acid, 3-methylthiopropionic acid, 3-phenylpropionic acid, 3-phenylisobutyric acid and 4-phenylbutyric acid, etc. Preferably it is glutaric acid or glycolic acid. Only one kind of the above-mentioned compound having a fluxing effect may be used, or two or more kinds may be used in combination.

From the viewpoint of effectively reducing the connection resistance in the connection structure and effectively suppressing the generation of pores, 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 a 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 groups of a compound having at least two carboxyl groups with the hydroxyl groups on the surface of the solder, conductive particles with carboxyl-containing groups covalently bonded to the surface of the solder can be obtained.

The manufacturing method of the said electroconductive particle has, for example, the step of using electroconductive particle, and mixing this electroconductive particle, the compound which has a functional group and a carboxyl group which can react with a hydroxyl group, a catalyst, and a solvent. In the manufacturing method of the said electroconductive particle, the electroconductive particle which the group containing a carboxyl group was covalently bonded to the surface of a solder can be obtained easily by the said mixing process.

In addition, in the above-mentioned method for producing conductive particles, it is preferable to use conductive particles, to mix the conductive particles, the above-mentioned compound having a functional group capable of reacting with a hydroxyl group and a carboxyl group, the above-mentioned catalyst and the above-mentioned solvent, and Heat up. Through the mixing and heating steps, conductive particles with carboxyl-containing groups covalently bonded to the surface of the solder can be more easily obtained.

As said solvent, alcohol solvents, such as methanol, ethanol, propanol, and butanol, or acetone, methyl ethyl ketone, ethyl acetate, toluene, xylene, etc. are mentioned. The above-mentioned solvent is preferably an organic solvent, more preferably toluene. Only one type of the above-mentioned solvent may be used, or two or more types may be used in combination.

As said catalyst, p-toluenesulfonic acid, benzenesulfonic acid, 10-camphorsulfonic acid, etc. are mentioned. The above-mentioned catalyst is preferably p-toluenesulfonic acid. Only one kind of the above-mentioned catalyst may be used, or two or more kinds may be used in combination.

It is preferable to heat during the above mixing. The heating temperature is preferably 90°C or higher, more preferably 100°C or higher, and preferably 130°C or lower, and more preferably 110°C or lower.

From the viewpoint of effectively reducing the connection resistance in the connection structure and effectively suppressing the generation of voids, the conductive particles are preferably obtained through the following steps: using an isocyanate compound, the hydroxyl group on the solder surface is combined with the isocyanate compound reaction. In the above reaction, a covalent bond is formed. By reacting the hydroxyl group on the surface of the solder with the above-mentioned isocyanate compound, it is possible to easily obtain conductive particles in which a nitrogen atom derived from an isocyanate group is covalently bonded to the surface of the solder. By reacting the hydroxyl group on the surface of the solder with the isocyanate compound, the group derived from the isocyanate group can be chemically bonded to the surface of the solder in the form of a covalent bond.

In addition, a group derived from an isocyanate group can be easily reacted with a silane coupling agent. As can The above-mentioned conductive particles are easily obtained. Therefore, the above-mentioned carboxyl-containing group is preferably introduced by a reaction using a silane coupling agent having a carboxyl group, or by reacting with a silane coupling agent to make The group reacts with a compound having at least one carboxyl group to be introduced. The conductive particles are preferably obtained by using the isocyanate compound to react the hydroxyl group on the solder surface with the isocyanate compound and then react with a compound having at least one carboxyl group.

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

As said isocyanate compound, diphenylmethane-4,4'-diisocyanate (MDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), etc. are mentioned. Isocyanate compounds other than these can also be used. After reacting the compound with the surface of the solder, the residual isocyanate group is reacted with a compound that is reactive with the residual isocyanate group and has a carboxyl group, whereby the carboxyl group can be introduced to the surface via the group represented by the above formula (X) The surface of the solder.

As the aforementioned isocyanate compound, a compound having an unsaturated double bond and an isocyanate group can also be used. For example, 2-propenoxyethyl isocyanate and 2-isocyanatoethyl methacrylate can be mentioned. By reacting the isocyanate group of the compound with the surface of the solder, and then reacting with a compound having a carboxyl group and a functional group reactive to the remaining unsaturated double bonds, the group represented by the above formula (X) The carboxyl group is introduced to the surface of the solder.

As the above-mentioned silane coupling agent, 3-isocyanatopropyltriethoxysilane ("KBE-9007" manufactured by Shin-Etsu Silicones), and 3-isocyanatopropyltrimethoxysilane ( "Y-5187" manufactured by MOMENTIVE Company) etc. Only one type of the above-mentioned silane coupling agent may be used, or two or more types may be used in combination.

As the above-mentioned compound having at least one carboxyl group, acetyl propionic acid, glutaric acid, Glycolic acid, succinic acid, malic acid, oxalic acid, malonic acid, adipic acid, 5-ketohexanoic acid, 3-hydroxypropionic acid, 4-aminobutyric acid, 3-mercaptopropionic acid, 3-mercaptoisobutyric acid , 3-methylthiopropionic acid, 3-phenylpropionic acid, 3-phenylisobutyric acid, 4-phenylbutyric acid, capric acid, dodecanoic acid, tetradecanoic acid, pentadecanoic acid, ten Hexadecanoic acid, 9-hexadecenoic acid, heptadecanoic acid, stearic acid, oleic acid, isoleic acid, linoleic acid, (9,12,15)-linolenic acid, nonadenoic acid, Arachidic acid, sebacic acid and dodecanedioic acid, etc. Preferably it is glutaric acid, adipic acid or glycolic acid. The above-mentioned compound having at least one carboxyl group may be used alone or in combination of two or more kinds.

After the above isocyanate compound is used to react the hydroxyl groups on the solder surface with the isocyanate compound, a part of the carboxyl groups of the compound having multiple carboxyl groups is reacted with the hydroxyl groups on the solder surface, thereby allowing the carboxyl-containing groups to remain.

In the above-mentioned method for producing conductive particles, conductive particles are used, and isocyanate compounds are used, and the hydroxyl groups on the solder surface are reacted with the isocyanate compounds, and then reacted with a compound having at least one carboxyl group to obtain the formula (X ) The conductive particles containing the carboxyl group are bonded to the surface of the solder. In the above-mentioned method for producing conductive particles, conductive particles having a carboxyl group-containing group introduced into the surface of the solder can be easily obtained by the above-mentioned steps.

As a specific manufacturing method of the said electroconductive particle, the following methods are mentioned. Disperse conductive particles in an organic solvent, and add a silane coupling agent having an isocyanate group. Then, the reaction catalyst of the hydroxyl group and isocyanate group on the solder surface of the conductive particles is used to covalently bond the silane coupling agent to the solder surface. Then, the alkoxy group bonded to the silicon atom of the silane coupling agent is hydrolyzed to generate a hydroxyl group. The generated hydroxyl group is reacted with the carboxyl group of a compound having at least one carboxyl group.

Moreover, as a specific manufacturing method of the said electroconductive particle, the following methods are mentioned. Make The conductive particles are dispersed in an organic solvent, and a compound having an isocyanate group and an unsaturated double bond is added. Thereafter, a reaction catalyst of the hydroxyl group on the solder surface of the conductive particle and the isocyanate group is used to form a covalent bond. Thereafter, the introduced unsaturated double bond is reacted with the unsaturated double bond and the compound having a carboxyl group.

As the reaction catalyst of the hydroxyl group on the solder surface of the conductive particles and the isocyanate group, examples include tin-based catalysts (dibutyltin dilaurate, etc.), amine-based catalysts (triethylenediamine, etc.), and carboxylate catalysts (Lead naphthenate, potassium acetate, etc.), and trialkylphosphine catalysts (triethylphosphine, etc.), etc.

From the viewpoint of effectively reducing the connection resistance in the connection structure and effectively suppressing the generation of voids, the compound having at least one carboxyl group is preferably a compound represented by the following formula (1). The compound represented by the following formula (1) has a fluxing effect. In addition, the compound represented by the following formula (1) has a fluxing effect when it is introduced to the surface of the solder.

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 carbon atoms, hydrogen atoms and oxygen atoms. The organic group may be a divalent hydrocarbon group with 1 to 5 carbon atoms. The main chain of the aforementioned organic group is preferably a divalent hydrocarbon group. In the organic group, a carboxyl group or a hydroxyl group may be bonded to the divalent hydrocarbon group. The compound represented by the above formula (1) contains citric acid, for example.

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

[化3]

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

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

Preferably, the base represented by the following formula (2A) or the following formula (2B) is bonded to the surface of the solder. It is preferable that the base represented by the following formula (2A) is bonded to the surface of the solder, and it is more preferable that the base represented by the following formula (2B) is bonded. In addition, in the following formula (2A) and the following formula (2B), the left end part represents a bonding site.

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

[化6]

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

From the viewpoint of improving the wettability of the solder surface, the molecular weight of the compound having at least one carboxyl group is preferably 10,000 or less, more preferably 1,000 or less, and still more preferably 500 or less.

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

In terms of effectively improving the aggregation of conductive particles at the time of conductive connection, the conductive particles preferably have a conductive particle body and an anionic polymer arranged on the surface of the conductive particle body. The above-mentioned conductive particles are preferably obtained by subjecting the conductive particle body to surface treatment with an anionic polymer or an anionic polymer compound. The conductive particles are preferably surface-treated products treated with an anionic polymer or a compound that becomes an anionic polymer. The above-mentioned anionic polymer and the above-mentioned anionic polymer-forming compound may use only one type, or two or more types may be used in combination. The above-mentioned anionic polymer is a polymer having an acidic group.

As a method of surface-treating the conductive particle body with an anionic polymer, the following methods can be cited: as an anionic polymer, for example, a (meth)acrylic polymer obtained by copolymerizing (meth)acrylic acid, A polyester polymer synthesized from dicarboxylic acid and diol and having carboxyl groups at both ends, obtained by the intermolecular dehydration condensation reaction of dicarboxylic acid and having carboxyl groups at both ends Polymers, polyester polymers synthesized from dicarboxylic acids and diamines with carboxyl groups at both ends, and modified polyvinyl alcohols with carboxyl groups (“Gohsenx T” manufactured by Nippon Synthetic Chemical Co., Ltd.), etc., make anionic polymers The carboxyl group reacts with the hydroxyl group on the surface of the conductive particle body.

The anionic portion of the anionic polymer include a carboxyl group, in addition, include toluene sulfonic acyl _{(pH 3 CC 6 H 4 S} (= O) 2 -), sulfonate ion group (-SO ₃ ^-) and phosphate ion group (-PO ₄ ^-) and the like.

In addition, as another method of surface treatment, the following method can be exemplified: using a compound having a functional group that reacts with the hydroxyl group on the surface of the conductive particle body, and further having a functional group that can be polymerized by addition or condensation reaction, to make the The compound is polymerized on the surface of the conductive particle body. Examples of the functional groups that react with the hydroxyl groups on the surface of the conductive particles include carboxyl groups and isocyanate groups. Examples of functional groups that undergo polymerization by addition and condensation reactions include hydroxyl groups, carboxyl groups, amine groups, and (formaldehyde). Base) Acrylic acid base.

The weight average molecular weight of the anionic polymer is preferably 2,000 or more, more preferably 3,000 or more, and preferably 10,000 or less, and more preferably 8,000 or less. If the weight average molecular weight is greater than or equal to the aforementioned lower limit and less than or equal to the aforementioned upper limit, a sufficient amount of charge and fluxing properties can be introduced to the surface of the conductive particles. Thereby, the agglomeration of conductive particles can be effectively improved during the conductive connection, and the oxide film on the electrode surface can be effectively removed during the connection of the connection target member.

If the weight average molecular weight is above the above lower limit and below the above upper limit, it is easy to dispose an anionic polymer on the surface of the conductive particle body, which can effectively improve the agglomeration of solder particles during conductive connection, and the conductive particles can be more Efficiently arranged on the electrode.

The above-mentioned weight average molecular weight means a weight average molecular weight measured by gel permeation chromatography (GPC) in terms of polystyrene.

The weight average molecular weight of the anionic polymer can be obtained by dissolving the solder in the conductive particles The solution is obtained by measuring the weight average molecular weight of the remaining anionic polymer after removing the conductive particles with dilute hydrochloric acid which does not cause decomposition of the anionic polymer.

Regarding the introduction amount of the anionic polymer to the surface of the conductive particles, the acid value per 1 g of the conductive particles is preferably 1 mgKOH or more, more preferably 2 mgKOH or more, and preferably 10 mgKOH or less, and more preferably 6 mgKOH or less.

The above-mentioned acid value can be measured by the following method. 1 g of conductive particles were added to 36 g of acetone, and ultrasonically dispersed for 1 minute. After that, using phenolphthalein as an indicator, titration was performed with a 0.1 mol/L potassium hydroxide ethanol solution.

Then, referring to the drawings, a specific example of the conductive particles will be described.

Fig. 5 is a cross-sectional view showing a first example of conductive particles that can be used for conductive materials.

The conductive particles 21 shown in FIG. 5 are solder particles. The conductive particles 21 are entirely formed of solder. The conductive particles 21 do not have substrate particles in the core, and are not core-shell particles. Both the center part and the outer surface part of the conductive part of the conductive particle 21 are formed by solder.

Fig. 6 is a cross-sectional view showing a second example of conductive particles that can be used for conductive materials.

The conductive particle 31 shown in FIG. 6 includes a base particle 32 and a conductive portion 33 arranged on the surface of the base particle 32. The conductive portion 33 covers the surface of the substrate particle 32. The conductive particles 31 are coated particles in which the surface of the substrate particle 32 is covered with the conductive portion 33.

The conductive portion 33 has a second conductive portion 33A and a solder portion 33B (first conductive portion). The conductive particle 31 includes a second conductive portion 33A between the base particle 32 and the solder portion 33B. Therefore, the conductive particle 31 includes the base particle 32, the second conductive portion 33A arranged on the surface of the base particle 32, and the solder portion 33B arranged on the outer surface of the second conductive portion 33A.

Fig. 7 is a cross-sectional view showing a third example of conductive particles that can be used for conductive materials.

As described above, the conductive portion 33 in the conductive particle 31 has a two-layer structure. Conductivity shown in Figure 7 The sexual particles 41 have a solder portion 42 as a single-layer conductive portion. The conductive particle 41 includes a base particle 32 and a solder portion 42 arranged on the surface of the base particle 32.

Examples of the substrate particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles. The above-mentioned substrate particles are preferably substrate particles other than metals, preferably resin particles, inorganic particles other than metal particles, or organic-inorganic hybrid particles. The aforementioned substrate particles may be copper particles. The substrate particles may have a core and a shell arranged on the surface of the core, and 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 above-mentioned resin particles, various organic substances can be preferably used. Examples of resins used to form the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; polymethacrylic acid Acrylic resins such as methyl ester and polymethyl acrylate; polycarbonate, 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 resin, saturated polyester resin, polyethylene terephthalate, polysulfide, polyphenylene ether, polyacetal, polyimide, polyimide imide, Polyether ether ketone, polyether agglomerate, divinylbenzene polymer, and divinylbenzene copolymer, etc. As said divinylbenzene copolymer etc., a divinylbenzene-styrene copolymer, a divinylbenzene-(meth)acrylate copolymer, etc. are mentioned. Since the hardness of the resin particles can be easily controlled within a preferred range, the resin used to form the resin particles is preferably made by polymerizing one or two or more polymerizable monomers with ethylenically unsaturated groups. Chengzhi polymer.

In the case of polymerizing a polymerizable monomer having an ethylenically unsaturated group to obtain the resin particles, examples of the polymerizable monomer having an ethylenically unsaturated group include non-crosslinkable monomers and crosslinking The monomer of sex.

As the above-mentioned non-crosslinkable monomers, for example, benzene such as styrene and α-methylstyrene Vinyl monomers; (meth)acrylic acid, maleic acid, maleic anhydride and other carboxyl-containing monomers; (meth)acrylate, ethyl (meth)acrylate, (meth)acrylic acid Propyl ester, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, ( Alkyl (meth)acrylate compounds such as cyclohexyl methacrylate and isoester (meth)acrylate; 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate (Meth)acrylate compounds containing oxygen atoms such as acrylate and glycidyl (meth)acrylate; nitrile monomers such as (meth)acrylonitrile; methyl vinyl ether, ethyl vinyl ether, propyl Vinyl ether compounds such as vinyl ether; acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate, and vinyl stearate; unsaturated hydrocarbons such as ethylene, propylene, isoprene, butadiene; Halogen-containing monomers such as trifluoromethyl meth)acrylate, pentafluoroethyl (meth)acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene.

Examples of the above-mentioned crosslinkable monomer include: tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, and tetramethylolmethane di(meth)acrylic acid Ester, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, glyceryl tri(meth)acrylate, di(meth)acrylic acid Glycerides, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, (poly)tetramethylene glycol di(meth)acrylate, 1,4- Multifunctional (meth)acrylate compounds such as butanediol di(meth)acrylate; triallyl (iso)cyanurate, triallyl trimellitate, divinylbenzene, diphthalate Allyl ester, diallyl acrylamide, diallyl ether; and γ-(meth)acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane Containing silane monomers, etc.

The above-mentioned resin particles can be obtained by polymerizing the above-mentioned polymerizable monomer having an ethylenically unsaturated group by a known method. As this method, for example, it can be listed in the initiation of radical polymerization The method of carrying out suspension polymerization in the presence of the agent, and the method of polymerizing the monomer by using non-crosslinked seed particles together with a radical polymerization initiator to swell the monomer.

When the above-mentioned substrate particles are inorganic particles or organic-inorganic mixed particles other than metals, examples of inorganic substances used to form the substrate particles include silica, alumina, barium titanate, zirconia, and carbon black Wait. The above-mentioned inorganic substance is preferably not a metal. The particles formed of silicon dioxide are not particularly limited. For example, a silicon compound having two or more hydrolyzable alkoxysilyl groups is hydrolyzed to form cross-linked polymer particles, and then as needed Particles obtained by calcination. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and acrylic resin.

In the case where the aforementioned substrate particles are metal particles, examples of the metal used to form the metal particles include silver, copper, nickel, silicon, gold, and titanium. When the aforementioned substrate particles are metal particles, the metal particles are preferably copper particles. However, it is preferable that the aforementioned substrate particles are not metal particles.

The particle size of the substrate particles is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, and preferably 100 μm or less, more preferably 50 μm or less, and still more preferably It is 40 μm or less, more preferably 20 μm or less, still more preferably 10 μm or less, particularly preferably 5 μm or less, and most preferably 3 μm or less. If the particle size of the substrate particles is greater than or equal to the above lower limit, the contact area between the conductive particles and the electrode becomes larger. Therefore, the reliability of conduction between the electrodes can be further improved, and the gap between the electrodes connected via the conductive particles can be further reduced. Connect resistance. If the particle size of the substrate particles is equal to or less than the above upper limit, the conductive particles can be easily compressed sufficiently, the connection resistance between the electrodes can be further reduced, and the distance between the electrodes can be further reduced.

The particle diameter of the aforementioned substrate particle represents the diameter when the substrate particle is a true spherical shape, and represents the maximum diameter when the substrate particle is not a true spherical shape.

The particle size of the aforementioned substrate particles is particularly preferably 2 μm or more and 5 μm or less. If the above substrate particles If the particle size is within the range of 2μm or more and 5μm or less, the distance between the electrodes can be further reduced, and even if the thickness of the conductive part is increased, smaller conductive particles can be obtained.

The method of forming a conductive part on the surface of the said base material particle, and the method of forming a solder part on the surface of the said base particle or the surface of the said 2nd conductive part are not specifically limited. As a method of forming the conductive portion and the solder portion, for example, a method using electroless plating, a method using electroplating, a method using physical collision, a method using mechanochemical reaction, a method using physical vapor deposition or physical adsorption can be mentioned. , And a method of coating the surface of the substrate particle with a paste containing metal powder or metal powder and a binder. Preferably, methods using electroless plating, electroplating or physical collision are used. As the method using the physical vapor deposition described above, methods such as vacuum vapor deposition, ion plating, and ion sputtering can be cited. In addition, in the above-mentioned method of using physical collision, for example, Thetacomposer (manufactured by Tokuju Works Co., Ltd.) is used.

The melting point of the substrate particle is preferably higher than the melting point of the conductive portion and the solder portion. The melting point of the substrate particles is preferably more than 160°C, more preferably more than 300°C, still more preferably more than 400°C, and particularly preferably more than 450°C. Furthermore, the melting point of the aforementioned substrate particles may not reach 400°C. The melting point of the aforementioned substrate particles may be 160°C or lower. The softening point of the substrate particles is preferably 260°C or higher. The softening point of the aforementioned substrate particles may not reach 260°C.

The said electroconductive particle may have a single-layer solder part. The above-mentioned conductive particles may have a plurality of layers of conductive parts (solder part, second conductive part). That is, in the above-mentioned conductive particles, two or more layers of conductive parts can be laminated. When the conductive part has two or more layers, the conductive particles preferably have solder on the outer surface of the conductive part.

The above-mentioned solder is preferably a metal (low melting point metal) having a melting point of 450°C or less. The solder portion is preferably a metal layer (low melting point metal layer) having a melting point of 450°C or less. The aforementioned low melting point metal layer is a layer containing a low melting point metal. The solder in the conductive particles is preferably a metal with a melting point of 450°C or less Particles (low melting point metal particles). The aforementioned low melting point metal particles are particles containing low melting point metals. The so-called low melting point metal refers to a metal having a melting point of 450°C or less. The melting point of the low melting point metal is preferably 300°C or less, more preferably 160°C or less. In addition, the solder in the conductive particles preferably contains tin. In 100% by weight of the metal contained in the solder portion and 100% by weight of the metal contained in the solder in the conductive particles, the content of tin is preferably 30% by weight or more, more preferably 40% by weight or more, and more preferably It is 70% by weight or more, particularly preferably 90% by weight or more. If the content of tin contained in the solder in the conductive particles is greater than or equal to the above lower limit, the reliability of conduction between the conductive particles and the electrode is further improved.

In addition, the content of tin can use a high frequency inductively coupled plasma emission spectrometer ("ICP-AES" manufactured by Horiba) or a fluorescent X-ray analyzer ("EDX-800HS" manufactured by Shimadzu) ) And so on.

By using conductive particles having solder on the outer surface of the conductive portion, the solder melts and joins the electrodes, and the solder conducts the electrodes. For example, since the solder and the electrode easily make surface contact rather than point contact, the connection resistance becomes low. In addition, by using conductive particles having solder on the outer surface of the conductive portion, the bonding strength between the solder and the electrode becomes higher, and as a result, it becomes more difficult to cause peeling of the solder and the electrode, and the conduction reliability is effectively improved.

The low melting point metal constituting the solder portion and the solder particles is not particularly limited. The low melting point metal is preferably tin or an alloy containing tin. Examples of the alloy include tin-silver alloy, tin-copper alloy, tin-silver-copper alloy, tin-bismuth alloy, tin-zinc alloy, tin-indium alloy, and the like. In terms of excellent wettability of the counter electrode, the aforementioned low melting point metal is preferably tin, tin-silver alloy, tin-silver-copper alloy, tin-bismuth alloy, and tin-indium alloy. More preferred are tin-bismuth alloys and tin-indium alloys.

Based on JIS Z3001: soldering terms, the material constituting the above-mentioned solder (solder portion) is preferably a filler material having a liquidus line of 450°C or less. As the composition of the above solder, for example, zinc, gold, Metal composition of silver, lead, copper, tin, bismuth, indium, etc. Preferably, it is a low melting point and lead-free tin-indium system (117°C eutectic) or tin-bismuth system (139°C eutectic). That is, the above-mentioned 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 improve the bonding strength between the solder and the electrode, the solder in the conductive particles may also contain nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, bismuth, manganese, and chromium. , Molybdenum, Palladium and other metals. In addition, from the viewpoint of further enhancing the bonding strength between the solder and the electrode, the solder in the conductive particles preferably contains nickel, copper, antimony, aluminum, or zinc. From the viewpoint of further improving the bonding strength between the solder in the solder portion or the conductive particles and the electrode, the content of these metals for increasing the bonding strength is in 100% by weight of the solder in the conductive particles, preferably 0.0001% by weight or more, and preferably 1% by weight or less.

The melting point of the second conductive portion is preferably higher than the melting point of the solder portion. The melting point of the second conductive part is preferably more than 160°C, more preferably more than 300°C, still more preferably more than 400°C, still more preferably more than 450°C, particularly preferably more than 500°C, most preferably more than 600°C . The above-mentioned solder part melts during conductive connection due to its low melting point. It is preferable that the above-mentioned second conductive portion does not melt during conductive connection. The conductive particles are preferably used by melting solder, preferably by melting the solder portion, and preferably by melting the solder portion without melting the second conductive portion. Since the melting point of the second conductive portion is higher than the melting point of the solder portion, it is possible to melt only the solder portion without melting the second conductive portion during conductive connection.

The absolute value of the difference between the melting point of the solder portion and the melting point of the second conductive portion exceeds 0°C, preferably 5°C or higher, more preferably 10°C or higher, still more preferably 30°C or higher, and particularly preferably 50°C or higher , The best temperature is above 100°C.

It is preferable that the said 2nd conductive part contains a metal. The metal constituting the second conductive portion is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, Indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and their alloys. In addition, as the above metal, tin-doped indium oxide (ITO) can be used. Only one kind of the above-mentioned metals may be used, or two or more kinds may be used in combination.

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 still more preferably a copper layer. The conductive particles preferably have a nickel layer, a palladium layer, a copper layer, or a gold layer, more preferably have a nickel layer or a gold layer, and still more preferably have a copper layer. By using the conductive particles with these better conductive parts for the connection between the electrodes, the connection resistance between the electrodes is further reduced. In addition, solder parts can be more easily formed on the surfaces of these better conductive parts.

The thickness of the aforementioned solder portion is preferably 0.005 μm or more, more preferably 0.01 μm or more, and preferably 10 μm or less, more preferably 1 μm or less, and still more preferably 0.3 μm or less. If the thickness of the solder portion is more than the above lower limit and below the above upper limit, sufficient conductivity can be obtained, the conductive particles will not become too hard, and the conductive particles will be sufficiently deformed during the connection between the electrodes.

The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 3 μm or more, and preferably 100 μm or less, more preferably 50 μm or less, and still more preferably 40 μm or less, particularly preferably It is 30μm or less. If the average particle size of the conductive particles is greater than or equal to the lower limit and less than the upper limit, the solder in the conductive particles can be more efficiently arranged on the electrodes, and it is easy to arrange a large amount of the solder in the conductive particles between the electrodes. The turn-on reliability is further improved.

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

The shape of the said electroconductive particle is not specifically limited. The shape of the said electroconductive particle may be spherical, and may be a shape other than a spherical shape, such as a flat shape.

In 100% by weight of the conductive material, the content of the conductive particles is preferably 1% by weight or more Above, it is more preferably 2% by weight or more, still more preferably 10% by weight or more, particularly preferably 20% by weight or more, most preferably 30% by weight or more, and preferably 80% by weight or less, more preferably 60% by weight Hereinafter, it is more preferably 50% by weight or less. If the content of the conductive particles is above the above lower limit and below the above upper limit, the solder in the conductive particles can be more efficiently arranged on the electrodes, and it is easy to arrange a large amount of the solder in the conductive particles between the electrodes, and conduction reliability Further improve. From the viewpoint of further improving the conduction reliability, the content of the conductive particles is preferably larger.

(Thermosetting compound)

The aforementioned thermosetting compound is a compound that can be cured by heating. Examples of the above-mentioned thermosetting compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth)acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, and polyurethane compounds. Ester compounds, polysiloxane compounds, polyimide compounds, etc. From the viewpoint of improving the curability and viscosity of the conductive material and further improving the connection reliability, an epoxy compound or an episulfide compound is preferable, and an epoxy compound is more preferable. The aforementioned conductive material preferably contains an epoxy compound. As for the said thermosetting compound, only 1 type may be used, and 2 or more types may be used together.

From the viewpoint of further suppressing the corrosion of the electrode and maintaining the connection resistance lower, the thermosetting compound preferably contains a thermosetting compound having a nitrogen atom, and preferably contains a thermosetting compound having a triple skeleton.

Examples of the above-mentioned thermosetting compounds having nitrogen atoms include triglycidyl ethers, etc., including TEPIC series manufactured by Nissan Chemical Industry Co., Ltd. (TEPIC-G, TEPIC-S, TEPIC-SS, TEPIC-HP, TEPIC-L , TEPIC-PAS, TEPIC-VL, TEPIC-UC) etc.

As said epoxy compound, aromatic epoxy compound is mentioned. Preferably, they are resorcinol type epoxy compounds, naphthalene type epoxy compounds, biphenyl type epoxy compounds, and benzophenone type epoxy compounds Crystalline epoxy compounds such as compounds. It is preferably an epoxy compound that is solid at normal temperature (23°C) and has a melting temperature below the melting point of the solder. The melting temperature is preferably 100°C or lower, more preferably 80°C or lower, and preferably 40°C or higher. By using the above-mentioned preferable epoxy compound, the viscosity is relatively high at the stage where the connection object member is attached, and when acceleration is given due to impact such as transportation, it can suppress the first connection object member and the second connection object member. Dislocation, and by the heat during hardening, the viscosity of the conductive material can be greatly reduced, and the agglomeration of the solder can be performed efficiently.

In 100% by weight of the conductive material, the content of the thermosetting compound is preferably 20% by weight or more, more preferably 40% by weight or more, still more preferably 50% by weight or more, and preferably 99% by weight or less, and more It is preferably 98% by weight or less, more preferably 90% by weight or less, and particularly preferably 80% by weight or less. If the content of the thermosetting compound is above the above lower limit and below the above upper limit, the solder in the conductive particles can be further efficiently arranged on the electrodes, further suppressing the dislocation between the electrodes, and further improving the reliability of the conduction between the electrodes Sex. From the viewpoint of further improving impact resistance, it is preferable that the content of the above-mentioned thermosetting compound is large. From the viewpoint of improving the curability and viscosity of the conductive material and further improving the connection reliability, the content of the epoxy compound in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 15% by weight Above, it is preferably 50% by weight or less, more preferably 30% by weight or less.

(Thermal hardener)

The thermosetting agent thermally hardens the thermosetting compound. As the above-mentioned thermal curing agent, there are imidazole curing agents, phenolic curing agents, mercaptan curing agents, amine curing agents, acid anhydride curing agents, thermal cation initiators (thermal cation curing agents), thermal radical generators, and the like. Only one kind of the above-mentioned thermosetting agent may be used, or two or more kinds may be used in combination.

The imidazole curing agent is not particularly limited, and examples include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyano trimellitate. Ethyl-2-phenylimidazolium salt, 2,4-Diamino-6-[2'-Methylimidazolyl-(1')]-Ethyl-Tris and 2,4-Diamino-6-[2'-Methylimidazolyl- (1')]-Ethyl-s-triisocyanuric acid adduct, etc.

The mercaptan curing agent is not particularly limited, and examples thereof include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(3-mercaptopropionate), and dipentaerythritol hexa(3-mercaptopropionic acid) Ester) and so on.

The solubility parameter of the aforementioned mercaptan hardener is preferably 9.5 or more, and preferably 12 or less. The above solubility parameters are 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 examples thereof include hexamethylene diamine, octane diamine, decane diamine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraspiro [5.5] Undecane, bis(4-aminocyclohexyl)methane, m-phenylenediamine and diaminodiphenyl sulfide, etc.

Examples of the thermal cationic initiator include: cationic hardeners, cationic hardeners, cationic hardeners, and the like. Examples of the above-mentioned cationic hardener of the cationic group include bis(4-tert-butylphenyl) hexafluorophosphate and the like. Examples of the above-mentioned cationic hardener include trimethyl tetrafluoroborate and the like. Examples of the above-mentioned alumium-based cationic curing agent include tris(p-tolyl)sulfonium hexafluorophosphate and the like.

It does not specifically limit as said thermal radical generator, An azo compound, an organic peroxide, etc. are mentioned. As said azo compound, azobisisobutyronitrile (AIBN) etc. are mentioned. As said organic peroxide, di-tert-butyl peroxide, methyl ethyl ketone peroxide, etc. are mentioned.

The reaction initiation temperature of the above-mentioned thermosetting agent is preferably 50°C or higher, more preferably 70°C or higher, still more preferably 80°C or higher, and preferably 250°C or lower, more preferably 200°C or lower, and still more preferably 150°C or less, especially 140°C or less, if the reaction initiation temperature of the thermal hardener is the above Above the upper limit and below the above upper limit, the solder is more efficiently arranged on the electrode. The reaction initiation temperature of the thermal hardener is particularly preferably 80°C or more and 140°C or less.

From the viewpoint of disposing the solder more efficiently on the electrode, the reaction initiation temperature of the thermal hardening agent is preferably higher than the melting point of the solder in the conductive particles, more preferably 5°C or more, and more It is preferably higher than 10°C.

The reaction initiation temperature of the above-mentioned thermal hardener means the temperature at which the exothermic peak in DSC starts to rise.

The content of the aforementioned 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 more preferably 100 parts by weight or less relative to 100 parts by weight of the thermosetting compound. More preferably, it is 75 parts by weight or less. If the content of the thermosetting agent is more than the above lower limit, it is easy to sufficiently harden the conductive material. If the content of the thermosetting agent is less than the above upper limit, the remaining thermosetting agent that is not involved in hardening after hardening is unlikely to remain, and the heat resistance of the hardened product is further improved.

(Flux)

The aforementioned conductive material preferably contains a flux. By using flux, the solder can be more effectively arranged on the electrode. The flux is not particularly limited. As the flux, fluxes generally used for solder bonding and the like can be used. The aforementioned conductive material may also contain no flux.

Examples of the above-mentioned flux include: zinc chloride, a mixture of zinc chloride and inorganic halides, a mixture of zinc chloride and inorganic acids, molten salts, phosphoric acid, phosphoric acid derivatives, organic halides, hydrazine, and organic acids And rosin etc. Only one kind of the above-mentioned flux may be used, or two or more kinds may be used in combination.

As said molten salt, ammonium chloride etc. are mentioned. As said organic acid, lactic acid, citric acid, stearic acid, glutamic acid, glutaric acid, etc. are mentioned. Examples of the rosin include activated rosin and non-activated rosin. The above-mentioned flux is preferably an organic acid or rosin having two or more carboxyl groups. The above-mentioned flux may be an organic acid having two or more carboxyl groups, or may be rosin. By using 2 The organic acid and rosin with carboxyl group can further improve the reliability of the conduction between the electrodes.

The rosin is a kind of rosin with rosin acid as the main component. The flux is preferably rosin, more preferably rosin acid. By using the better flux, the reliability of conduction between the electrodes is further improved.

The activation temperature (melting point) of the aforementioned flux is preferably 50°C or higher, more preferably 70°C or higher, still more preferably 80°C or higher, and preferably 200°C or lower, more preferably 190°C or lower, and still more preferably 160°C or lower, more preferably 150°C or lower, and still more preferably 140°C or lower. If the activation temperature of the flux is above the above lower limit and below the above upper limit, the flux effect is more effectively exhibited, and the solder can be more efficiently arranged on the electrode. The activation temperature (melting point) of the aforementioned flux is preferably 80°C or higher and 190°C or lower. The activation temperature (melting point) of the above-mentioned flux is particularly preferably 80°C or more and 140°C or less.

Examples of the above-mentioned fluxes whose active temperature (melting point) of the flux is above 80°C and below 190°C include: succinic acid (melting point 186°C), glutaric acid (melting point 96°C), and adipic acid (melting point 152°C) , Pimelic acid (melting point 104°C), suberic acid (melting point 142°C) and other dicarboxylic acids; benzoic acid (melting point 122°C), malic acid (melting point 130°C), etc.

Moreover, it is preferable that the boiling point of the said flux is 200 degrees C or less.

From the viewpoint of disposing the solder more efficiently on the electrode, the melting point of the flux is preferably higher than the melting point of the solder in the conductive particles, more preferably 5°C or more, and more preferably 10 ℃ above.

From the viewpoint of disposing the solder more efficiently on the electrode, the melting point of the above-mentioned flux is preferably higher than the reaction initiation temperature of the above-mentioned thermal hardener, more preferably at least 5°C higher, and still more preferably 10 ℃ above.

The above-mentioned flux may be dispersed in a conductive material, or may be attached to the surface of the conductive particle.

The melting point of the flux is higher than the melting point of the solder, so that the solder can efficiently aggregate on the electrode part Minute. The reason is that when heat is applied during bonding, if the electrode formed on the connection object member is compared with the part of the connection object member around the electrode, the thermal conductivity of the electrode part is higher than the part of the connection object member around the electrode. The thermal conductivity, so the electrode part heats up faster. At the stage exceeding the melting point of the solder in the conductive particles, although the solder in the conductive particles is melted, since the melting point (activation temperature) of the flux is not reached, the oxide film formed on the surface is not removed. In this state, since the temperature of the electrode part first reaches the melting point (activation temperature) of the flux, the oxide film on the surface of the solder in the conductive particles reaching the electrode is preferentially removed, or the activated flux will increase the conductivity The charge on the surface of the solder in the particles is neutralized, whereby the solder can wet and spread to the surface of the electrode. Thereby, the solder can be efficiently aggregated on the electrode.

The above-mentioned flux is preferably a flux that releases cations by heating. By using a flux that releases cations by heating, the solder can be more efficiently arranged on the electrode.

Examples of the fluxes that release cations by heating include the above-mentioned thermal cationic initiators.

In 100% by weight of the conductive material, the content of the flux is preferably 0.5% by weight or more, and preferably 30% by weight or less, and more preferably 25% by weight or less. If the content of the flux is more than the above lower limit and below the above upper limit, it becomes more difficult to form an oxide film on the surface of the solder and the electrode, and the oxide film formed on the surface of the solder and the electrode can be removed more effectively.

(Other ingredients)

The above-mentioned conductive material may optionally contain, for example, fillers, extenders, softeners, plasticizers, polymerization catalysts, hardening catalysts, colorants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, and lubricants. , Antistatic agent and flame retardant and other additives.

(Connection structure and manufacturing method of connection structure)

The connection structure of the present invention is provided with a first connection object structure having at least one first electrode on the surface A second connection object member having at least one second electrode on the surface, and a connection portion that connects the first connection object member and the second connection object member. In the connection structure of the present invention, the material of the connection part is the above-mentioned conductive material, and the connection part is a cured product of the above-mentioned conductive material. In the connection structure of the present invention, the first electrode and the second electrode are electrically connected by a solder portion in the connection portion.

The method of manufacturing the connection structure includes: using the conductive material, arranging the conductive material on the surface of a first connection object member having at least one first electrode on the surface; using the first electrode and the second In the method of facing the electrodes, the second connection object member having at least one second electrode on the surface is arranged on the surface of the conductive material opposite to the first connection object member side; by heating the conductive material to The solder in the conductive particles has a melting point or higher, and the conductive material forms a connecting portion that connects the first connection object member and the second connection object member, and the solder portion in the connection portion connects the first The step of electrically connecting the electrode and the second electrode. It is preferable to heat the said conductive material to the hardening temperature of the said thermosetting component and thermosetting compound or more.

In the connection structure of the present invention and the method of manufacturing the connection structure described above, since a specific conductive material is used, the solder in the plurality of conductive particles is likely to gather between the first electrode and the second electrode, and the solder can be It is efficiently arranged on the electrode (line). In addition, it is difficult to arrange a part of the solder in the area (space) where the electrode is not formed, and the amount of the solder to be arranged in the area where the electrode is not formed can be very small. Therefore, the reliability of conduction between the first electrode and the second electrode can be improved. And it can prevent the electrical connection between the laterally adjacent electrodes that cannot be connected, and can improve the insulation reliability.

In addition, in order to efficiently arrange the solder in a plurality of conductive particles on the electrode and to reduce the amount of the solder arranged in the area where the electrode is not formed, it is preferable to use a conductive paste instead of a conductive paste. Electric film.

The thickness of the solder portion between the electrodes is preferably 10 μm or more, more preferably 20 μm or more, and preferably 100 μm or less, and more preferably 80 μm or less. The solder wetting area on the surface of the electrode (the area in contact with the solder out of 100% of the exposed electrode area) is preferably 50% or more, more preferably 60% or more, more preferably 70% or more, and more preferably Below 100%.

In the method of manufacturing the connection structure of the present invention, in the step of arranging the second connection object member and the step of forming the connection portion, it is preferable to apply the second connection object to the conductive material without applying pressure For the weight of the member, in the step of arranging the second connection object member and the step of forming the connection portion, it is preferable that no pressure is applied to the conductive material that exceeds the weight of the second connection object member. In these situations, the uniformity of the amount of solder in the plurality of solder portions can be further improved. Furthermore, the thickness of the solder portion can be increased more effectively, the solder in the conductive particles becomes easy to gather in a large amount between the electrodes, and the solder in the conductive particles can be more efficiently arranged on the electrode (wire) on. In addition, it is difficult to arrange a part of the solder in the plurality of conductive particles in the area (space) where the electrode is not formed, and the amount of solder to be arranged in the conductive particle in the area where the electrode is not formed can be reduced. Therefore, the reliability of conduction between the electrodes can be further improved. In addition, the electrical connection between the laterally adjacent electrodes that cannot be connected can be further prevented, and the insulation reliability can be further improved.

It has also been found that in the step of arranging the second connection object member and the step of forming the connection portion, if the conductive material is not pressurized and the weight of the second connection object member is applied to the conductive material, it is arranged before the connection portion is formed The solder in the region (space) where the electrode is not formed is more likely to gather between the first electrode and the second electrode, and the solder in the plurality of conductive particles can be more efficiently arranged on the electrode (line). In the present invention, a configuration that uses conductive paste instead of a conductive film is combined with a configuration that applies the weight of the second connection target member to the conductive paste without applying pressure The adoption is of greater significance for obtaining the effects of the present invention at a higher level.

Furthermore, in WO2008/023452A1, it is described that in terms of squeezing the solder powder to flow to the electrode surface and move it efficiently, it is preferable to pressurize with a specific pressure when adhering, and it is described that From the viewpoint of forming the solder region more reliably, the pressurizing pressure is set to, for example, 0 MPa or more, preferably 1 MPa or more, and further describes that the pressure deliberately applied to the adhesive tape can be 0 MPa, or it can be arranged on the adhesive tape The weight of the upper member exerts a specific pressure on the adhesive tape. It is stated in WO2008/023452A1 that the pressure deliberately applied to the adhesive tape can be 0 MPa, but there is no description about the difference between the effect of applying a pressure exceeding 0 MPa and the case of setting it to 0 MPa. Furthermore, WO2008/023452A1 has no knowledge about the importance of using paste-like conductive paste instead of film-like.

In addition, if a conductive paste is used instead of a conductive film, it becomes easy to adjust the thickness of the connection part and the solder part by the application amount of the conductive paste. On the other hand, with regard to the conductive film, there is a problem that in order to change or adjust the thickness of the connection part, it is necessary to prepare conductive films of different thicknesses or to prepare conductive films of specific thicknesses. In addition, in terms of conductive film, compared with conductive paste, the melting viscosity of the conductive film cannot be sufficiently reduced at the melting temperature of the solder, which tends to hinder the aggregation of the solder.

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

Fig. 2 is a cross-sectional view schematically showing a connection structure obtained by using a conductive material according to an embodiment of the present invention.

The connection structure 1 shown in FIG. 2 includes a first connection object member 2, a second connection object member 3, and a connection portion 4 that connects the first connection object member 2 and the second connection object member 3. The connecting portion 4 is formed of the aforementioned conductive material. In this embodiment, the conductive material contains solder particles as conductive particles.

The connection part 4 has a solder part 4A where a plurality of solder particles are gathered and joined to each other, and heat-hardened The cured product part 4B formed by thermal curing of the chemical component.

The first connection object member 2 has a plurality of first electrodes 2a on the surface (upper surface). The second connection object member 3 has a plurality of second electrodes 3a on the surface (lower surface). The first electrode 2a and the second electrode 3a are electrically connected by the solder portion 4A. Therefore, the first connection object member 2 and the second connection object member 3 are electrically connected by the solder portion 4A. In addition, in the connection part 4, the solder does not exist in the area|region (hardened part 4B part) different from the solder part 4A gathered between the 1st electrode 2a and the 2nd electrode 3a. There is no solder separated from the solder part 4A in a region different from the solder part 4A (hardened product part 4B part). Furthermore, if it is a small amount, the solder may exist in the area|region (hardened part 4B part) different from the solder part 4A which gathered between the 1st electrode 2a and the 2nd electrode 3a.

As shown in Figure 2, in the connection structure 1, a plurality of solder particles are gathered between the first electrode 2a and the second electrode 3a. After the plurality of solder particles are melted, the molten material of the solder particles wets and spreads on the surface of the electrode. After curing, the solder portion 4A is formed. Therefore, the connection area between the solder portion 4A and the first electrode 2a, and the connection area between the solder portion 4A and the second electrode 3a increases. That is, by using solder particles, the solder portion 4A and the first electrode 2a, and the solder portion 4A and the second electrode are compared with the case of using conductive particles whose outer surface is nickel, gold, or copper. The contact area of 3a increases. Therefore, the conduction reliability and connection reliability of the connection structure 1 are improved.

Furthermore, the conductive material may also contain flux. When using flux, the flux is usually gradually deactivated due to heating.

Furthermore, in the connection structure 1 shown in FIG. 2, all the solder portions 4A are located in the opposing regions between the first and second electrodes 2a, 3a. In the connection structure 1X of the modified example shown in FIG. 4, only the connection part 4X is different from the connection structure 1 shown in FIG. The connection part 4X has a solder part 4XA and a hardened part 4XB. Like the connection structure 1X, most of the solder portion 4XA is located in the area where the first and second electrodes 2a, 3a face each other, and a part of the solder portion 4XA is from the first and second electrodes 2a, 3a. The opposing area extends sideways. The solder part 4XA that protrudes laterally from the area facing the first and second electrodes 2a, 3a is a part of the solder part 4XA, and is not a solder separated from the solder part 4XA. Furthermore, in this embodiment, the amount of the solder separated from the solder part can be made smaller, but the solder separated from the solder part may also exist in the hardened part.

If the amount of solder particles used is reduced, the connection structure 1 becomes easier to obtain. If the amount of solder particles used is increased, it becomes easier to obtain the connection structure 1X.

From the viewpoint of further improving the conduction reliability, when viewing the opposing part of the first electrode and the second electrode in the direction of the stacking of the first electrode, the connecting portion, and the second electrode, it is preferably 50% or more (more preferably 60% or more, still more preferably 70% or more, particularly preferably 80% or more of the area of 100% of the opposing parts of the above-mentioned first electrode and the second electrode 90% or more) Configure the solder part in the above-mentioned connection part.

From the viewpoint of further improving the conduction reliability, when viewing the opposing part of the first electrode and the second electrode along the stacking direction of the first electrode, the connecting portion, and the second electrode, regarding the first electrode, 1 The ratio of the area of the electrode and the second electrode facing each other in 100% of the area where the solder part in the connecting part is arranged, the ratio of the area of the electrode in the center part to the area of the electrode in the outer peripheral part The difference in the ratio is preferably less than 15%, more preferably less than 10%, and still more preferably less than 5%.

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

First, the first connection object member 2 having the first electrode 2a on the surface (upper surface) is prepared. Next, as shown in FIG. 3(a), a conductive material 11 containing a thermosetting component 11B and a plurality of solder particles 11A is arranged on the surface of the first connection object member 2 (first step). The conductive material 11 used contains a thermosetting compound and a thermosetting agent as the thermosetting component 11B.

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

The arrangement method of the conductive material 11 is not particularly limited, and examples include coating by a dispenser, screen printing, and ejection by an inkjet device.

In addition, the second connection object member 3 having the second electrode 3a on the surface (lower surface) is prepared. Next, as shown in FIG. 3(b), of the conductive material 11 on the surface of the first connection object member 2, the second connection is arranged on the surface of the conductive material 11 on the side opposite to the first connection object member 2 side Object component 3 (Step 2). On the surface of the conductive material 11, the second connection object member 3 is arranged 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 the melting point of the solder particles 11A or higher (the third step). It is preferable to heat the conductive material 11 to the curing temperature of the thermosetting component 11B (adhesive) or higher. During this heating, the solder particles 11A existing in the area where the electrode is not formed gather between the first electrode 2a and the second electrode 3a (self-aggregation effect). When a conductive paste is used instead of a conductive film, the solder particles 11A are effectively gathered between the first electrode 2a and the second electrode 3a. In addition, the solder particles 11A are melted and joined to each other. In addition, the thermosetting component 11B undergoes thermosetting. As a result, as shown in FIG. 3(c), the conductive material 11 is used to form the connection portion 4 that connects the first connection object member 2 and the second connection object member 3. The connecting portion 4 is formed by the conductive material 11, the solder portion 4A is formed by joining a plurality of solder particles 11A, and the thermosetting component 11B is thermally cured to form the cured product portion 4B.

In this embodiment, it is preferable not to pressurize in the second step and the third step. In this case, the weight of the second connection object member 3 is applied to the conductive material 11. Therefore, when the connecting portion 4 is formed, the solder particles 11A are effectively collected between the first electrode 2a and the second electrode 3a. between. Furthermore, if pressurization is performed in at least one of the second step and the third step, the effect of gathering solder particles between the first electrode and the second electrode tends to be hindered.

In addition, in this embodiment, since pressure is not applied, when the second connection object member is superimposed on the first connection object member coated with the conductive material, the electrode of the first connection object member and the second connection object When the alignment of the electrode of the member is misaligned, even when the first connection target member and the second connection target member are overlapped, the misalignment can be corrected and the electrode of the first connection target member can be connected to the second The electrode connection of the target component (automatic alignment effect). The reason is that the self-agglomerated molten solder occurs between the electrode of the first connection object member and the electrode of the second connection object member, and the solder between the electrode of the first connection object member and the electrode of the second connection object member When the area in contact with other components of the conductive material becomes the smallest, it becomes stable in terms of energy. Therefore, the connection structure that becomes the smallest area, that is, the force of the aligned connection structure acts. At this time, it is preferable that the conductive material is not hardened, and the viscosity of the components other than the conductive particles of the conductive material is sufficiently low under the conditions of the temperature and time.

In this way, the connection structure 1 shown in FIG. 2 is obtained. Furthermore, the above-mentioned second step and the above-mentioned third step may be performed continuously. Furthermore, after performing the above-mentioned second step, the obtained layered body of the first connection object member 2 and the conductive material 11 and the second connection object member 3 may be moved to the heating part, and then the above-mentioned third step may be performed. In order to perform the heating, the laminate may be arranged on a heating member, or the laminate may be arranged in a heated space.

The heating temperature in the third step is preferably 140°C or higher, more preferably 160°C or higher, and preferably 450°C or lower, more preferably 250°C or lower, and still more preferably 200°C or lower.

As the heating method in the above-mentioned third step, there can be mentioned a method of using a reflow furnace or an oven to heat the entire connecting structure to a temperature higher than the melting point of the solder and the hardening temperature of the thermosetting component, or only connecting the structure The part is locally heated to above the melting point of the solder Divide the method above the hardening temperature.

The aforementioned first and second connection target members are not particularly limited. Specific examples of the above-mentioned first and second connection target members include electronic components such as semiconductor wafers, semiconductor packages, LED (Light Emitting Diode) wafers, LED packages, capacitors, and diodes; and Electronic components such as resin films, printed circuit boards, flexible printed circuit boards, flexible flat cables, rigid flexible boards, glass epoxy substrates, and circuit boards such as glass substrates. The first and second connection target members are preferably electronic components.

Preferably, 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 circuit board. Preferably, the second connection object member is a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible board. Resin film, flexible printed circuit board, flexible flat cable and rigid flexible board have the properties of high flexibility and relatively light weight. When the conductive film is used for the connection of such a connection object member, there is a tendency that the solder is difficult to collect on the electrode. In contrast, by using conductive paste, even if a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible board is used, the solder can be efficiently collected on the electrodes to sufficiently improve the reliability of conduction between the electrodes. . When using a resin film, a flexible printed circuit board, a flexible flat cable or a rigid flexible circuit board, compared to the use of other connection objects such as semiconductor chips, the conduction between electrodes due to no pressure can be obtained more effectively The effect of improving reliability.

In the form of the above-mentioned connection target member, there are surrounding arrays or area arrays. As a feature of each component, the electrodes in the peripheral array substrate only exist on the outer periphery of the substrate. The electrodes in the area array substrate exist in the plane.

Examples of the electrodes provided on the connection target member 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 object 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 object member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. Furthermore, when the above-mentioned electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode with an aluminum layer on the surface area of the metal oxide layer. As the material of the metal oxide layer, indium oxide doped with trivalent metal element, zinc oxide doped with trivalent metal element, etc. can be cited. As said trivalent metal element, Sn, Al, Ga, etc. are mentioned.

Hereinafter, examples and comparative examples are given to specifically explain the present invention. The present invention is not limited to the following examples.

Polymer A:

Synthesis of the reactant (polymer A) of bisphenol F, 1,6-hexanediol diglycidyl ether, and bisphenol F epoxy resin:

Bisphenol F (containing 4,4'-methylene bisphenol, 2,4'-methylene bisphenol and 2,2'-methylene bisphenol in a weight ratio of 2:3:1) 72 weight Parts, 70 parts by weight of 1,6-hexanediol diglycidyl ether, and 30 parts by weight of bisphenol F type epoxy resin ("EPICLON EXA-830CRP" manufactured by DIC Corporation) were put into a three-necked flask and placed in a nitrogen stream, Dissolve at 150°C. Then, 0.1 parts by weight of tetra-n-butyl arumium bromide as a catalyst for the addition reaction of the hydroxyl group and the epoxy group was added, and the addition polymerization reaction was carried out at 150°C under a nitrogen stream for 6 hours to obtain a reaction物(Polymer A).

The addition polymerization reaction was confirmed by NMR (nuclear magnetic resonance), and the reactant (polymer A) had a hydroxyl group derived from bisphenol F and 1,6-hexanediol diglycidyl ether in the main chain. , And a structural unit formed by bonding epoxy groups of bisphenol F epoxy resin, and have epoxy groups at both ends.

The weight average molecular weight of the reactant (polymer A) obtained by GPC is 10000, and the quantity The average molecular weight is 3500.

Thermosetting compound 1: Resorcinol type epoxy compound, "EX-201" manufactured by Nagase chemteX

Thermohardener 1: Mercaptan thermohardener, "Karenz MT" manufactured by Showa Denko Corporation

Thermal hardener 2: Microcapsule type thermal hardener, "HXA3922HP" manufactured by Asahi Kasei E-MATERIALS

Latent thermosetting agent 1: "FUJICURE 7000" manufactured by T&K TOKA

Flux 1: Glutaric acid, manufactured by Wako Pure Chemical Industries, Ltd.

Coupling agent 1: Silane coupling agent, "KBE-9007" manufactured by Shin-Etsu Silicones

Solder particles 1:

Manufacturing method of solder particles 1:

Using p-toluenesulfonic acid as a catalyst, SnBi solder particles ("ST-5" manufactured by Mitsui Metals Co., Ltd., average particle size (median diameter) 5μm) and glutaric acid (a compound with 2 carboxyl groups, and "Glutaric acid" manufactured by Kopure Pure Chemical Industry Co., Ltd.) was dehydrated in toluene solvent at 90°C and stirred for 8 hours to obtain solder particles 1 with carboxyl-containing groups covalently bonded to the surface of the solder.

In the obtained solder particles 1, the CV (Coefficient of Variation) value is 20%, and the molecular weight Mw of the polymer constituting the surface is 2000.

(Examples 1 to 6 and Comparative Examples 1 and 2)

(1) Production of anisotropic conductive paste

The components shown in Table 1 below were blended in the blending amounts shown in Table 1 below to obtain an anisotropic conductive paste.

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

As the first connection target member, 250μm copper electrodes are arranged in an area array with a 400μm pitch on the surface of the semiconductor wafer body (size 5×5mm, thickness 0.4mm), and a passivation film (polyimide) is formed on the outermost surface. , A semiconductor wafer with a thickness of 5μm and an electrode opening diameter of 200μm). Regarding the number of copper electrodes, a total of 100 pieces of 10×10 pieces per semiconductor wafer.

As the second connection object member, the surface of the glass epoxy substrate body (size 20×20mm, thickness 1.2mm, material FR-4) is prepared, and copper is arranged so that the electrode of the first connection object member has the same pattern Electrodes, and a glass epoxy substrate with solder resist film is formed in the area where no copper electrode is arranged. The step difference between the surface of the copper electrode and the surface of the solder mask is 15 μm, and the solder mask is more prominent than the copper electrode.

The anisotropic conductive paste just after manufacture is coated on the upper surface of the epoxy glass substrate by a dispenser to form an anisotropic conductive paste layer. The coating method of the anisotropic conductive paste layer was performed so that the center diameter of the above-mentioned epoxy glass substrate became 2.5 mm. Next, the above-mentioned semiconductor wafer is layered on the surface area of the anisotropic conductive paste layer so that the electrodes face each other. The weight of the aforementioned semiconductor wafer is applied to the anisotropic conductive paste layer.

Heating was performed so that the temperature of the anisotropic conductive paste layer became 139°C (melting point of solder) after 5 seconds from the start of the temperature rise. Furthermore, the temperature of the anisotropic conductive paste layer 15 seconds after the start of the temperature rise Heating is performed so that the temperature becomes 160°C to harden the anisotropic conductive paste to obtain a connection structure. No pressure is applied during heating.

(3) Fabrication of the second connection structure (surrounding substrate)

As the first member to be connected, 250μm copper electrodes are arranged (arranged around) on the outer periphery of the wafer at 400μm pitch on the surface of the semiconductor wafer body (size 5×5mm, thickness 0.4mm), and a passivation film is formed on the outermost surface. (Polyimide, thickness 5μm, electrode opening diameter 200μm) semiconductor wafer. Regarding the number of copper electrodes, a total of 36 pieces of 10 × 4 sides per semiconductor wafer.

As the second connection object member, a copper electrode is arranged on the surface of the epoxy glass substrate body (size 20×20mm, thickness 1.2mm, 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 with the solder resist film and the surface of the solder resist film in the area where the copper electrode is not arranged is 15μm, and the solder resist film is more prominent than the copper electrode.

The anisotropic conductive paste just after manufacture is coated on the upper surface of the epoxy glass substrate by a dispenser to form an anisotropic conductive paste layer. The coating method of the anisotropic conductive paste layer was performed so that the center diameter of the above-mentioned epoxy glass substrate became 2.5 mm. Next, the above-mentioned semiconductor wafer is layered on the surface area of the anisotropic conductive paste layer so that the electrodes face each other. The weight of the aforementioned semiconductor wafer is applied to the anisotropic conductive paste layer.

Heating was performed so that the temperature of the anisotropic conductive paste layer became 139°C (melting point of solder) after 5 seconds from the start of the temperature rise. Furthermore, heating was performed so that the temperature of the anisotropic conductive paste layer became 160 degreeC after 15 seconds from the start of the temperature increase, the anisotropic conductive paste was hardened, and the connection structure was obtained. No pressure is applied during heating.

(Evaluation)

(1) Viscosity

Using STRESSTECH (manufactured by EOLOGICA), under the conditions of strain control 1rad, frequency 1Hz, heating rate 20℃/min, and measuring temperature range of 25~200℃, measure the viscosity (η25) of anisotropic conductive paste at 25℃, And the viscosity at 100°C (η100).

(2) Determination of exothermic peak P1 and endothermic peak P2 by DSC

The thermosetting components in the anisotropic conductive pastes of the examples and comparative examples were blended. Using a differential scanning calorimetry device ("Q2000" manufactured by TA Instruments), heating the obtained thermosetting component at a temperature increase rate of 10°C/min, the exothermic peaks P1 and P2 derived from the curing of the above thermosetting component Perform the measurement.

Furthermore, using a differential scanning calorimeter ("Q2000" manufactured by TA Instruments), the conductive particles were heated at a temperature increase rate of 10°C/min, and the endothermic peak P3 derived from the melting of the solder in the conductive particles was measured.

The results of 1) to 9) below are shown in Table 1 below.

1) Whether the temperature region showing the endothermic peak P3 derived from the melting of the solder in the conductive particles overlaps with the temperature region showing the exothermic peak P1 derived from the hardening of the thermosetting component

2) Whether the temperature region showing the endothermic peak P3 derived from the melting of the solder in the conductive particles overlaps with the temperature region showing the exothermic peak P2 derived from the hardening of the thermosetting component

3) P1t temperature of exothermic peak of hardening derived from thermosetting components

4) P2t temperature at the top of the exothermic peak derived from the hardening of the thermosetting component

5) P3t temperature at the top of the endothermic peak derived from the melting of the solder in the conductive particles

6) The absolute value of the difference between the P3t temperature at the top of the endothermic peak and the P1t temperature at the top of the exothermic peak

7) The absolute value of the difference between the P3t temperature of the endothermic peak and the P2t temperature of the exothermic peak

8) The total exothermic heat derived from the hardening of the thermosetting component in the temperature region below the P3t temperature of the endothermic peak (low temperature side)

9) The total exothermic heat derived from the hardening of the thermosetting component in the temperature region above the P3t temperature of the endothermic peak (high temperature side)

The results of 10) and 11) below are also shown in Table 1 below.

10) The peak end temperature (X1) on the high temperature side of the endothermic peak derived from the melting of the solder in the conductive particles and the peak end temperature (Y1) on the high temperature side of the exothermic peak derived from the highest temperature side of the hardening of the thermosetting component Relations; listed in Table 1 as X1<Y1, X1=Y1 or X1>Y1.

11) The peak onset temperature (X2) of the low temperature side of the endothermic peak derived from the melting of the solder in the conductive particles and the peak on the low temperature side of the low temperature side of the exothermic peak of the hardening of the thermosetting component (Y2) ); listed in Table 1 as X2<Y2, X2=Y2 or X2>Y2.

In the evaluation of 1) and 2) above, the "-" shown as a result indicates that there is no peak. In the above-mentioned evaluations of 10) and 11), "-" shown as a result means that the evaluation is not performed.

(3) The placement accuracy of solder on the electrode 1

In the obtained connection structure, when the first electrode and the second electrode facing each other are observed along the stacking direction of the first electrode, the connection part and the second electrode in the center part, the difference between the first electrode and the second electrode The ratio X of the area where the solder part in the connecting part is arranged in 100% of the area of the parts facing each other is evaluated. Determine the placement accuracy of the solder on the electrode according to the following criteria1.

[Judgment criteria for the placement accuracy of solder on the electrode 1]

○○: Ratio X is 90% or more

○: The ratio X is 80% or more but less than 90%

△: The ratio X is 60% or more but less than 80%

×: The ratio X has not reached 60%

(4) The placement accuracy of solder on the electrode 2

In the obtained connection structure, the first electrode, the connection part and the second electrode along the outer periphery When observing the opposing part of the first electrode and the second electrode in the stacking direction, 100% of the solder part in the connecting part is arranged in the connecting part of the first electrode and the second electrode. The ratio Y is evaluated. Determine the placement accuracy of the solder on the electrode according to the following criteria2.

[Judgment criteria for placement accuracy of solder on electrode 2]

○○: Ratio X is 90% or more

○: The ratio X is 80% or more but less than 90%

△: The ratio X is 60% or more but less than 80%

×: The ratio X has not reached 60%

(5) The placement accuracy of solder in the substrate 3

In the obtained connection structure, when the first electrode and the second electrode facing each other are viewed along the stacking direction of the first electrode, the connecting portion, and the second electrode, the relationship between the first electrode and the second electrode The ratio of the area of 100% of the area of the opposite part to the area of the solder part in the connecting part is evaluated, and the difference Z between the ratio of the area of the electrode in the center part and the ratio of the area of the electrode in the outer peripheral part is evaluated. Determine the placement accuracy of solder in the board according to the following criteria3.

[Judgment criteria for the placement accuracy of solder in the board 3]

○○: The difference Z is less than 5%

○: The difference Z is 5% or more but less than 10%

△: The difference Z is more than 10% and less than 15%

×: Difference Z is 15% or more

(6) Reliability of conduction between upper and lower electrodes

In the obtained connection structure (n=15), the connection resistance between the upper and lower electrodes was measured by the four-terminal method. Calculate the average value of the connection resistance. Furthermore, based on the relationship of voltage=current×resistance, the connection resistance can be obtained by measuring the voltage when a constant current flows. According to the following basis Quasi-determine the reliability of conduction.

[Judgment criteria for continuity reliability]

○○: The average value of the connection resistance is 8.0Ω or less

○: The average value of the connection resistance exceeds 8.0Ω and is below 10.0Ω

△: The average value of connection resistance exceeds 10.0Ω and is below 15.0Ω

×: The average value of connection resistance exceeds 15.0Ω

The results are shown in Table 1 below.

The same tendency can be seen when using flexible printed circuit boards, resin films, flexible flat cables, and rigid flexible boards.

Claims (10)

A conductive material comprising a plurality of conductive particles having solder on the outer surface of a conductive part, and a thermosetting component, and heating the conductive particles and the above conductive particles at a heating rate of 10°C/min from 25°C. When performing differential scanning calorimetry for thermosetting components, the temperature region showing the endothermic peak derived from the melting of the solder in the conductive particles and the temperature region showing the exothermic peak derived from the hardening of the thermosetting component overlap at least in part , And the total exothermic heat derived from the hardening of the thermosetting component in the temperature range below the endothermic peak temperature of the melting of the solder in the conductive particles is smaller than that derived from the melting of the solder in the conductive particles The total exothermic heat derived from the hardening of the above-mentioned thermosetting component in the temperature region above the endothermic peak temperature. The conductive material of claim 1, wherein the first exothermic peak temperature derived from the hardening of the thermosetting component exists on the lower side than the endothermic peak temperature derived from the melting of the solder in the conductive particles, and There is a second exothermic peak temperature derived from the hardening of the thermosetting component on the higher temperature side than the endothermic peak temperature derived from the melting of the solder in the conductive particles. The conductive material of claim 2, wherein the absolute value of the difference between the endothermic peak top temperature and the first exothermic peak top temperature is 3°C or more and 60°C or less, and the endothermic peak top temperature and the second exothermic peak top temperature The absolute value of the difference is above 5℃ and below 60℃. Such as the conductive material of claim 1 or 2, wherein the end temperature of the peak on the high temperature side of the endothermic peak is low The peak end temperature on the high temperature side of the above exothermic peak on the highest temperature side. The conductive material of claim 1 or 2, wherein the end temperature of the peak on the high temperature side of the endothermic peak is lower than the peak end temperature on the high temperature side of the exothermic peak on the highest temperature side, and the peak start temperature on the low temperature side of the endothermic peak is higher than the lowest The peak start temperature on the low temperature side of the above exothermic peak on the warm side. The conductive material of claim 1 or 2, wherein the conductive particles are solder particles. The conductive material of claim 1 or 2 has a carboxyl group on the outer surface of the conductive particle. Such as the conductive material of claim 1 or 2, which is liquid and conductive paste at 25°C. A connection structure comprising a first connection object member having at least one first electrode on the surface, a second connection object member having at least one second electrode on the surface, and connecting the first connection object member and the second The connection part to which the object member is connected, and the connection part is a hardened product of a conductive material as in any one of claims 1 to 8, and the first electrode and the second electrode are electrically connected by the solder part in the connection part . The connection structure of claim 9, wherein when the portion of the first electrode and the second electrode facing each other is viewed in the direction of the stacking of the first electrode, the connecting portion, and the second electrode, the first electrode More than 50% of the 100% of the area of the portion of the electrode and the second electrode facing each other is provided with the solder portion in the connection portion.

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