TWI798321B - Solder particle, conductive material, storage method of solder particle, storage method of conductive material, production method of conductive material, connection structure and production method of connection structure - Google Patents

Abstract

The present invention provides a solder particle capable of effectively improving solder agglomeration during conductive connection. The solder particle of the present invention is a solder particle having an oxide film on the surface, and the particle size of the above-mentioned solder particle is not less than 1 μm and not more than 15 μm. When the above-mentioned solder particle is heated at 120° C. The ratio of the average thickness of the oxide film to the average thickness of the oxide film after heating is 2/3 or less.

Description

Solder particle, conductive material, storage method of solder particle, storage method of conductive material, production method of conductive material, connection structure and production method of connection structure

The present invention relates to, for example, solder particles that can be used for electrical connection between electrodes and a storage method for the solder particles. Also, the present invention relates to a conductive material including the above-mentioned solder particles, a method for storing the conductive material, and a method for producing the conductive material. Moreover, this invention relates to the manufacturing method of the connection structure using the said solder particle or the said conductive material, and a connection structure.

Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. The above-mentioned anisotropic conductive material has conductive particles dispersed in the binder. As said electroconductive particle, a solder particle is widely used.

The aforementioned anisotropic conductive materials are used to obtain various connection structures. As the connection by the above-mentioned anisotropic conductive material, for example, the connection between a flexible printed substrate and a glass substrate (FOG (Film on Glass, coated glass)), the connection between a semiconductor chip and a flexible printed substrate (COF (Chip on Film) , film-on-chip)), the connection between the semiconductor chip and the glass substrate (COG (Chip on Glass, glass-on-glass)), and the connection between the flexible printed substrate and the glass epoxy resin substrate (FOB (Film on Board, film-covered board) )wait.

For example, when the electrodes of the flexible printed circuit board and the electrodes of the glass epoxy resin substrate are electrically connected through the above-mentioned anisotropic conductive material, the anisotropic conductive material including conductive particles is arranged on the glass epoxy resin substrate. Next, the flexible printed circuit board is laminated, and heating and pressure are performed. Thereby, the anisotropic conductive material is hardened, and between electrodes are electrically connected via electroconductive particle, and the connection structure is obtained.

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

Patent Document 1 describes: a resin heating step of heating the anisotropic conductive resin to a temperature higher than the melting point of the conductive particles and the curing of the resin component is not completed, and a resin component hardening step of hardening the resin component And the electrodes are electrically connected. In addition, Patent Document 1 describes mounting with a temperature profile shown in FIG. 8 of Patent Document 1. In Patent Document 1, at the heating temperature of the anisotropic conductive resin, the conductive particles are melted in the resin component that has not yet been hardened.

Patent Document 2 below discloses a solder material including a solder layer and a coating layer that covers the surface of the solder layer. The above-mentioned solder layer includes a metal material containing an alloy with a Sn content of 40% or more or a metal material with a Sn content of 100%. The coating layer includes a SnO film and a SnO ₂ film. The SnO film is formed on the outer surface side of the solder layer. The aforementioned SnO ₂ film is formed on the outer surface side of the aforementioned SnO film. The thickness of the coating layer is greater than 0 nm and not more than 4.5 nm. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2004-260131 [Patent Document 2] WO2016/031067A1

[Problem to be solved by the invention]

In recent years, the industry is advancing the fine pitch of wiring on printed wiring boards and the like. Accordingly, for conductive materials including solder particles or conductive particles having solder on their surfaces, miniaturization and particle size reduction of solder particles or conductive particles having solder on their surfaces are being promoted.

When reducing the particle size of solder particles, etc., it may be difficult to efficiently agglomerate solder particles, etc., between the upper and lower electrodes to be connected during conductive connection using a conductive material. In particular, when the conductive material is heated and hardened, the viscosity of the conductive material increases before the solder particles and the like sufficiently move to the electrodes, and the solder particles and the like may remain in the region without electrodes. As a result, there are cases where the conduction reliability between electrodes to be connected and the insulation reliability between adjacent electrodes that cannot be connected may not be sufficiently improved.

Moreover, since the surface area of a solder particle etc. increases with the particle size reduction of a solder particle etc., the content of the oxide film on the surface of a solder particle etc. also increases. If there is an oxide film on the surface of the solder particles, etc., the solder particles, etc., cannot be efficiently aggregated on the electrodes. Therefore, conventional conductive materials require countermeasures such as increasing the flux content in the conductive material. However, if the content of the flux in the conductive material is increased, there may be cases where the flux reacts with the thermosetting component in the conductive material, resulting in a decrease in the storage stability of the conductive material or the heat resistance of the cured product of the conductive material. reduce. Also, if the content of the flux in the conductive material is increased, voids may be generated in the cured product of the conductive material, or poor curing of the conductive material may occur.

It is difficult for conventional conductive materials to meet all the requirements of improving solder aggregation during conductive connection, improving storage stability of conductive materials, and improving heat resistance of cured products of conductive materials.

An object of the present invention is to provide a solder particle and a storage method for the solder particle that can effectively improve the solder cohesion at the time of conductive connection. Moreover, the object of this invention is to provide the electroconductive material containing the said solder particle, the storage method of an electroconductive material, and the manufacturing method of an electroconductive material. Moreover, the object of this invention is to provide the manufacturing method of the connection structure which used the said solder particle or the said electrically-conductive material, and a connection structure. [Technical means to solve the problem]

According to a broader aspect of the present invention, there is provided a solder particle having a solder particle body and an oxide film disposed on the outer surface of the solder particle body, and the particle diameter of the solder particle is 1 μm or more. And 15 μm or less, when the solder particles are heated at 120° C. for 10 hours in an air environment, the ratio of the average thickness of the oxide film before heating to the average thickness of the oxide film after heating is 2/3 or less.

In a specific aspect of the solder particles of the present invention, the absolute value of the heat generation at 200° C. or higher is 100 mJ/mg or higher.

According to a broader aspect of the present invention, a conductive material may be provided, which includes a thermosetting component and a plurality of solder particles, and the solder particles have a solder particle body and an outer surface of the solder particle body. Oxide film, the particle size of the above-mentioned solder particles is not less than 1 μm and not more than 15 μm, when the above-mentioned solder particles are heated at 120°C for 10 hours in an air environment, the average thickness of the above-mentioned oxide film before heating is compared with that after heating The average thickness ratio of the oxide film is 2/3 or less.

In a specific aspect of the conductive material of the present invention, the viscosity at 25° C. is not less than 10 Pa·s and not more than 600 Pa·s.

In a specific aspect of the conductive material of the present invention, the viscosity measured by using an E-type viscometer at 25°C and 0.5 rpm is divided by the viscosity measured by using an E-type viscometer at 25°C and 5 rpm The thixotropic index obtained from the viscosity is not less than 1.1 and not more than 5.

In a specific aspect of the conductive material of the present invention, the absolute value of the amount of heat released by the solder particles at 200° C. or higher is 100 mJ/mg or higher.

In a specific aspect of the conductive material of the present invention, the above-mentioned conductive material is a conductive paste.

According to a broader aspect of the present invention, there is provided a storage method for solder particles, which is a storage method for the above-mentioned solder particles, and includes storing the above-mentioned solder particles in a storage container under an inert gas atmosphere, or storing the solder particles in an inert gas atmosphere. The above-mentioned solder particles are placed in a storage container and vacuum-stored under the condition of 1×10 ² Pa or less.

According to a broader aspect of the present invention, there is provided a method for storing conductive materials, which is the storage method for the above-mentioned conductive materials, and the method is to put the above-mentioned conductive materials in a storage container and store them at -40°C or higher and 10°C Store under the following conditions, or store the above-mentioned conductive material in a storage container under an inert gas atmosphere.

According to a broader aspect of the present invention, there is provided a method for producing a conductive material, which includes a mixing step of mixing a thermosetting component and a plurality of solder particles to obtain a conductive material, and the method for producing a conductive material obtains Conductive material as follows: the above-mentioned solder particle has a solder particle body and an oxide film arranged on the outer surface of the above-mentioned solder particle body, the particle size of the above-mentioned solder particle is not less than 1 μm and not more than 15 μm, and the above-mentioned solder particle is placed in an air environment When heating at 120° C. for 10 hours, the ratio of the average thickness of the oxide film before heating to the average thickness of the oxide film after heating is 2/3 or less.

In a specific aspect of the manufacturing method of the conductive material of the present invention, it further includes a storage step of storing the above-mentioned solder particles, and the above-mentioned storage step is a step of storing the above-mentioned solder particles in a storage container under an inert gas atmosphere , or a step of putting the above-mentioned solder particles into a storage container and storing them in a vacuum under the condition of 1×10 ² Pa or less, and the above-mentioned solder particles are solder particles stored in the above-mentioned storage step.

According to a broader aspect of the present invention, there can be provided a connection structure comprising a first connection object member having a first electrode on its surface, a second connection object member having a second electrode on its surface, and connecting the first connection object A connection portion between a member and the second connection object member, wherein the material of the connection portion includes the solder particles, and the first electrode and the second electrode are electrically connected by the solder portion in the connection portion.

According to a broader aspect of the present invention, there can be provided a connection structure comprising a first connection object member having a first electrode on its surface, a second connection object member having a second electrode on its surface, and connecting the first connection object The connection part between the member and the second connection object member, and the material of the connection part is the above-mentioned conductive material, and the first electrode and the second electrode are electrically connected by the solder part in the connection part.

According to a broader aspect of the present invention, there is provided a method of manufacturing a connection structure, which includes the steps of: using a conductive material containing the above-mentioned solder particles, disposing on the surface of a first connection object member having a first electrode on the surface The above-mentioned conductive material; the second connection object member having the second electrode on the surface is arranged on the surface of the above-mentioned conductive material opposite to the side of the first connection object member in such a manner that the above-mentioned first electrode and the above-mentioned second electrode are opposed; and By heating the conductive material above the melting point of the solder particles, the connection portion connecting the first connection object member and the second connection object member is formed from the above conductive material, and the solder portion in the connection portion connects The first electrode is electrically connected to the second electrode.

According to a broader aspect of the present invention, there is provided a method of manufacturing a connection structure, which includes the following steps: using the above-mentioned conductive material to arrange the above-mentioned conductive material on the surface of the first connection object member having the first electrode on the surface; The second connection object member having the second electrode on the surface is disposed on the surface of the conductive material opposite to the first connection object member in such a manner that the first electrode and the second electrode face each other; The material is heated above the melting point of the above-mentioned solder particles, and the connection part connecting the above-mentioned first connection object member and the above-mentioned second connection object member is formed by the above-mentioned conductive material, and the above-mentioned first electrode and the above-mentioned first electrode are connected by the solder part in the above-mentioned connection part. The above-mentioned second electrodes are electrically connected. [Effect of Invention]

The solder particle of the present invention has a solder particle body and an oxide film arranged on the outer surface of the solder particle body. In the solder particle of the present invention, the particle diameter of the above-mentioned solder particle is not less than 1 μm and not more than 15 μm. In the solder particles of the present invention, when the solder particles are heated at 120° C. for 10 hours in an air environment, the ratio of the average thickness of the oxide film before heating to the average thickness of the oxide film after heating is 2/3 the following. Since the solder particle of this invention has the said structure, it can effectively improve the solder aggregation property at the time of a conductive connection.

The conductive material of the present invention includes a thermosetting component and a plurality of solder particles. In the conductive material of the present invention, the solder particle has a solder particle body and an oxide film arranged on an outer surface of the solder particle body. In the conductive material of the present invention, the particle size of the above-mentioned solder particles is not less than 1 μm and not more than 15 μm. In the conductive material of the present invention, when the solder particles are heated at 120° C. for 10 hours in an air environment, the ratio of the average thickness of the oxide film before heating to the average thickness of the oxide film after heating is 2/3 the following. Since the conductive material of the present invention has the above-mentioned constitution, it can effectively improve the solder agglomeration during conductive connection.

The manufacturing method of the conductive material of this invention is equipped with the mixing process which mixes a thermosetting component and several solder particles, and obtains a conductive material. In the manufacturing method of the conductive material of this invention, the said solder particle has a solder particle main body, and the oxide film arrange|positioned on the outer surface of the said solder particle main body. In the manufacturing method of the conductive material of this invention, the particle diameter of the said solder particle is 1 micrometer or more and 15 micrometers or less. In the manufacturing method of the conductive material of the present invention, the following conductive material is obtained: when the above-mentioned solder particles are heated at 120° C. for 10 hours in an air environment, the average thickness of the above-mentioned oxide film before heating is compared with the average thickness of the oxide film after heating. The average thickness ratio is 2/3 or less. In the method for producing a conductive material of the present invention, since the above-mentioned structure is provided, it is possible to effectively improve the solder agglomeration at the time of conductive connection.

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

(solder particles) The solder particle of the present invention has a solder particle body and an oxide film arranged on the outer surface of the solder particle body. In the solder particle of the present invention, the particle diameter of the above-mentioned solder particle is not less than 1 μm and not more than 15 μm. In the solder particles of the present invention, when the solder particles are heated at 120° C. for 10 hours in an air environment, the ratio of the average thickness of the oxide film before heating to the average thickness of the oxide film after heating is 2/3 the following.

Since the solder particle of this invention has the said structure, it can effectively improve the solder aggregation property at the time of a conductive connection.

Compared with the conventional conductive material containing solder particles with a particle size of about 35 μm, the conductive material containing solder particles with a particle size of 10 μm or less has the following problem: the solder cannot be used for conductive connection. Particles are efficiently aggregated between the upper and lower electrodes that should be connected. The inventors of the present invention have carried out diligent research in order to solve the above-mentioned problems, and found that the reasons for the above-mentioned problems are: as the particle size of the solder particles becomes smaller, the oxide film on the surface of the solder particles becomes relatively thick; The increase of the surface area increases the content of the oxide film present on the surface of the solder particles. Furthermore, the inventors of the present invention conducted intensive studies to solve the above-mentioned problems, and as a result, found that the above-mentioned problems can be solved by controlling the oxide film existing on the surface of the solder particle to a specific thickness. In the present invention, although the size of the solder particles is reduced, the movement of the solder particles to the electrodes is sufficiently advanced, the solder can be efficiently aggregated between the electrodes to be connected, and the conduction reliability and insulation reliability can be improved.

Fig. 5 is a diagram for explaining the agglomeration of solder particles. Fig. 5 is a diagram of heating solder particles under various conditions (4 kinds of particle sizes and the presence or absence of controlled oxide film thickness) and confirming whether the solder particles are aggregated or not.

Regarding the solder particles whose thickness of the oxide film is not controlled in FIG. 5 , it can be understood that the smaller the particle size of the solder particles is, the less the solder particles will aggregate. The reason is: as the particle size of the solder particles becomes smaller, the oxide film existing on the surface of the solder particle becomes relatively thicker; and due to the increase in the surface area of the solder particle, the content of the oxide film present on the surface of the solder particle Increase.

Regarding the solder particles whose thickness of the oxide film was not controlled, it was confirmed that the solder particles agglomerated and one large solder aggregate was formed in the case of the solder particles whose particle size was 35 μm. In the case of solder particles with a particle diameter of 10 μm, the solder particles aggregated to form solder aggregates, but unaggregated solder particles were confirmed around the solder aggregates. For the solder particles whose particle diameters were 2 μm and 5 μm, it was confirmed that the solder particles were not aggregated at all, and no solder aggregates were formed.

On the other hand, regarding the solder particles whose thickness of the oxide film was controlled in FIG. 5 , it was confirmed that the solder particles aggregated regardless of the particle diameter of the solder particles, forming one large solder aggregate. It can be understood that in order to improve the cohesiveness of solder particles, it is important to control the oxide film existing on the surface of solder particles to a specific thickness.

Also, in the present invention, by controlling the oxide film existing on the surface of the solder particle to a specific thickness, the solder particle can be efficiently aggregated on the electrode, so there is no need to increase the content of the flux in the conductive material excessively. . As a result, the reaction between the thermosetting component in the conductive material and the flux can be effectively suppressed, and the storage stability of the conductive material can be effectively improved.

Also, the melting point (activation temperature) of the flux in the conductive material is often lower than the Tg of the thermosetting component in the conductive material, and the more the flux content in the conductive material becomes, the harder the conductive material will be. The lower the heat resistance of the material tends to be. Since the present invention does not need to excessively increase the flux content in the conductive material, it can effectively improve the heat resistance of the cured product of the conductive material. Moreover, since the present invention does not need to increase the content of flux in the conductive material excessively, it can effectively suppress the generation of voids in the cured product of the conductive material, and can effectively suppress the occurrence of poor hardening of the conductive material.

Since the present invention has the above structure, it can meet all the requirements of improving the solder aggregation property during conductive connection, improving the storage stability of the conductive material, and improving the heat resistance of the cured product of the conductive material.

In the present invention, in order to obtain the above effects, it is very helpful to control the oxide film existing on the surface of the solder particle to a specific thickness.

The solder particle has a solder particle body and an oxide film disposed on the outer surface of the solder particle body. Both the central part and the outer surface of the solder particle body are formed of solder. The above-mentioned solder particles are particles of solder in the central part and outer surface of the system. The above-mentioned oxide film is formed by oxidizing the outer surface of the above-mentioned solder particle body by oxygen in the air. The above-mentioned oxide film includes tin oxide and the like. Generally speaking, the outer surface of commercially available solder particles is oxidized by oxygen in the air and has an oxide film.

When the conductive particles having substrate particles formed of a material other than solder and solder portions disposed on the surface of the substrate particles are used instead of the solder particles, the conductive particles are less likely to gather on the electrodes. In addition, since the above-mentioned conductive particles have low solder bondability between conductive particles, the conductive particles that have moved to the electrodes tend to move out of the electrodes, and the effect of suppressing positional displacement between electrodes is also reduced. tendency.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. In addition, in the following drawings, the size, thickness, shape, etc. may be different from the actual size, thickness, shape, etc. for the convenience of illustration.

Fig. 4 is a cross-sectional view showing an example of solder particles that can be used for conductive materials.

The solder particle 21 shown in FIG. 4 has a solder particle body 22 and an oxide film 23 disposed on the outer surface of the solder particle body 22 . The solder particle body 22 is in contact with the oxide film 23 . The entire solder particle body 22 is formed of solder. The solder particle body 22 does not have a base material particle in the core, and is not a core-shell particle. Both the central portion and the outer surface of the solder particle body 22 are formed of solder.

The aforementioned solder is preferably a metal having a melting point of 450° C. or lower (low melting point metal). The above-mentioned solder particles are preferably metal particles having a melting point of 450° C. or lower (low melting point metal particles). The above-mentioned low-melting-point metal particles are particles containing a low-melting-point metal. The low-melting point metal refers to a metal having a melting point of 450°C or lower. The melting point of the low melting point metal is preferably not higher than 300°C, more preferably not higher than 160°C. The above-mentioned solder particles are preferably low-melting-point solder whose melting point is less than 150°C.

The melting point of the above-mentioned solder particles can be obtained by differential scanning calorimetry (DSC). As a differential scanning calorimetry (DSC) apparatus, "EXSTAR DSC7020" by SII company etc. are mentioned.

Moreover, it is preferable that the said solder particle contains tin. The content of tin is preferably at least 30% by weight, more preferably at least 40% by weight, further preferably at least 70% by weight, and most preferably at least 90% by weight, in 100% by weight of the metal contained in the solder particles. The connection reliability of a solder part and an electrode becomes it still higher that content of tin in the said solder particle is more than the said minimum.

Furthermore, the content of the above-mentioned tin can be determined using a high-frequency inductively coupled plasma emission spectrometer ("ICP-AES" manufactured by Horiba Corporation), or a fluorescent X-ray analyzer ("EDX-800HS" manufactured by Shimadzu Corporation). ) etc. to measure.

By using the above-mentioned solder particles, the solder is melted and bonded to the electrodes, and the solder is solidified to form a solder portion that provides electrical conduction between the electrodes. For example, since the solder portion and the electrode are easily in surface contact rather than point contact, the connection resistance becomes low. In addition, the use of the above-mentioned solder particles increases the bonding strength between the solder portion and the electrode, and as a result, peeling between the solder portion and the electrode is less likely to occur, and conduction reliability and connection reliability are further improved.

The metal constituting the above-mentioned solder particles is not particularly limited. The metal is preferably tin or an alloy containing tin. Examples of such alloys include tin-silver alloys, tin-copper alloys, tin-silver-copper alloys, tin-bismuth alloys, tin-zinc alloys, and tin-indium alloys. The aforementioned metal is preferably tin, tin-silver alloy, tin-silver-copper alloy, tin-bismuth alloy, and tin-indium alloy in terms of excellent wettability to the electrode. More preferred are tin-bismuth alloys and tin-indium alloys.

Regarding the above-mentioned solder particles, based on JIS Z3001: Welding terms, it is preferable to be a filler material whose liquidus is 450° C. or less. As a composition of the said solder particle, the metal composition containing zinc, gold, silver, lead, copper, tin, bismuth, indium, etc. is mentioned, for example. It is preferably low melting point and lead-free tin-indium system (117°C eutectic) or tin-bismuth system (139°C eutectic). That is, it is preferable that the said solder particle does not contain lead, and it is preferable to contain tin and indium, or contain tin and bismuth.

In order to further improve the joint strength between the solder part and the electrode, the above-mentioned solder particles may also contain nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, bismuth, manganese, chromium, molybdenum, palladium and other metals. Moreover, it is preferable that the said solder particle contains nickel, copper, antimony, aluminum, or zinc from a viewpoint of further improving the joint strength of a solder part and an electrode. From the viewpoint of further improving the bonding strength between the solder portion and the electrode, the content of the metals for increasing the bonding strength is preferably 0.0001% by weight or more and preferably 1% by weight or less in 100% by weight of the solder particles.

In the solder particle of the present invention, the particle diameter of the above-mentioned solder particle is not less than 1 μm and not more than 15 μm. The particle size of the solder particles is preferably not less than 1 μm, more preferably not less than 2 μm, and preferably not more than 10 μm, more preferably not more than 5 μm. Solder aggregation property at the time of electrically conductive connection can be improved more effectively that the particle diameter of the said solder particle is more than the said minimum and below the said upper limit. The particle diameter of the above-mentioned solder particles is preferably not less than 2 μm and not more than 5 μm.

The particle diameter of the above-mentioned solder particles is preferably an average particle diameter, and is preferably a number average particle diameter. The particle size of the solder particles is obtained by observing arbitrary 50 solder particles with an electron microscope or an optical microscope, calculating the average value of the particle sizes of the respective solder particles, or performing a laser diffraction particle size distribution measurement. In the observation with an electron microscope or an optical microscope, the particle diameter per one solder particle was determined as the particle diameter in terms of circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter in terms of circle equivalent diameter and the average particle diameter in terms of spherical equivalent diameter of any 50 solder particles are approximately equal. In the laser diffraction particle size distribution measurement, the particle diameter per one solder particle is calculated as the particle diameter in terms of spherical equivalent diameter. It is preferable to calculate the average particle diameter of the said solder particle by laser diffraction particle size distribution measurement.

The coefficient of variation (CV value) of the particle size of the solder particles is preferably at least 5%, more preferably at least 10%, and is preferably at most 40%, more preferably at most 30%. Solder can be arrange|positioned on an electrode more uniformly as the variation coefficient of the particle diameter of the said solder particle is more than the said minimum and below the said upper limit. However, the CV value of the particle diameter of the said solder particle may be less than 5%.

The said coefficient of variation (CV value) can be measured as follows.

CV value (%)=(ρ/Dn)×100 ρ: Standard deviation of particle size of solder particles Dn: average particle size of solder particles

The shape of the above-mentioned solder particles is not particularly limited. The shape of the above-mentioned solder particles may be spherical, or may be flat or other shapes other than the spherical shape.

In the solder particle of the present invention, when the above-mentioned solder particle is heated at 120° C. for 10 hours in an air environment, the average thickness (average thickness A) of the above-mentioned oxide film before heating is relative to the average thickness (average thickness A) of the oxide film after heating ( The ratio of average thickness B) (average thickness A/average thickness B) is 2/3 or less. The above ratio (average thickness A/average thickness B) is preferably 1/2 or less. The lower limit of the ratio (average thickness A/average thickness B) is not particularly limited. The said ratio (average thickness A/average thickness B) may be 1/100 or more, 1/50 or more, or 1/10 or more. The solder aggregation property at the time of electrically conductive connection can be improved more effectively that the said ratio (average thickness A/average thickness B) is below the said upper limit. When the said ratio (average thickness A/average thickness B) is below the said upper limit, the storage stability of a conductive material can be improved more effectively, and the heat resistance of the hardened|cured material of a conductive material can be improved more effectively. Moreover, when the said ratio (average thickness A/average thickness B) is below the said upper limit, it can use suitably for the use of a conductive material. Moreover, when the said ratio (average thickness A/average thickness B) is more than the said minimum, the handleability of the electrically-conductive material containing the said solder particle can be improved more effectively. In addition, since the meltability of the surface of the solder particles during heating can be appropriately controlled by setting the ratio (average thickness A/average thickness B) above the above-mentioned lower limit to below the above-mentioned upper limit, it is considered that the solder aggregates during conductive connection Sex will become high more effectively.

The solder particles of the present invention control the oxide film before heating to a specific thickness (the oxide film is relatively thin), so by heating at 120°C for 10 hours in an air environment, the thickness of the oxide film is increased to meet the above ratio. (average thickness A/average thickness B). The previous solder particles had a relatively thick oxide film before heating, so there was not enough room for oxidation. Even if they were heated at 120°C for 10 hours in an air environment, the thickness of the oxide film would not increase so much, and the above ratio (average Thickness A/average thickness B).

The average thickness (average thickness A) of the above-mentioned oxide film before heating is preferably at least 1 nm, more preferably at least 2 nm, and is preferably at most 5 nm, more preferably at most 4 nm. When the average thickness (average thickness A) of the said oxide film before heating is more than the said minimum and below the said upper limit, the solder aggregation property at the time of electrically conductive connection can be improved more effectively. Also, if the average thickness (average thickness A) of the above-mentioned oxide film before heating is not less than the above-mentioned lower limit and not more than the above-mentioned upper limit, the storage stability of the conductive material can be improved more effectively, and further, the hardening of the conductive material can be improved more effectively. Material heat resistance. Moreover, if the average thickness (average thickness A) of the said oxide film before heating is more than the said minimum, it can use preferably for the use of a conductive material.

The average thickness (average thickness A) of the said oxide film before heating can be calculated|required by observing the cross-section of a solder particle using a transmission electron microscope, for example. The average thickness (average thickness A) of the said oxide film before heating can be calculated from the average value of the thickness of the oxide film of 10 arbitrarily selected locations, for example.

The ratio of the average thickness of the oxide film before heating (average thickness A) to the particle size of the solder particles (average thickness A/solder particle size) is preferably 0.0001 or more, more preferably 0.0005 or more, and still more preferably It is 0.001 or more, preferably 0.01 or less, more preferably 0.008 or less, still more preferably 0.005 or less. When the said ratio (average thickness A/particle diameter of a solder particle) is more than the said minimum and below the said upper limit, the solder aggregation property at the time of electrically conductive connection can be improved more effectively. Also, if the above-mentioned ratio (average thickness A/particle size of solder particles) is more than the above-mentioned lower limit and below the above-mentioned upper limit, the storage stability of the conductive material can be improved more effectively, and furthermore, the cured product of the conductive material can be improved more effectively. The heat resistance.

In 100% by volume of the above-mentioned solder particles, the content of the oxide film is preferably at least 0.1% by volume, more preferably at least 0.5% by volume, and is preferably at most 10% by volume, more preferably at most 8% by volume, and still more preferably at least 8% by volume. 5% by volume or less. The solder aggregation property at the time of conductive connection can be improved more effectively that content of the said oxide film is more than the said minimum and below the said upper limit. Moreover, when the content of the above-mentioned oxide film is more than the above-mentioned lower limit and not more than the above-mentioned upper limit, the storage stability of the conductive material can be improved more effectively, and further, the heat resistance of the cured product of the conductive material can be improved more effectively.

The content of the oxide film can be calculated from the weight of the solder particles before and after the oxide film is removed.

The absolute value of the exothermic heat of the solder particles above 200°C is preferably at least 100 mJ/mg, more preferably at least 200 mJ/mg, and is preferably at most 400 mJ/mg, more preferably at most 300 mJ/mg. It is considered that the absolute value of the amount of heat released by the above-mentioned solder particles at 200° C. or higher varies depending on the thickness of the oxide film on the surface of the solder particles or the like. If the absolute value of the heat generation at 200° C. or higher is not less than the above lower limit and not more than the above upper limit, the solder agglomeration at the time of conductive connection can be improved more effectively.

The amount of heat released by the solder particles above 200°C can be obtained by differential scanning calorimetry (DSC). As a differential scanning calorimetry (DSC) apparatus, "EXSTAR DSC7020" by SII company etc. are mentioned.

The above-mentioned solder particles can be obtained, for example, by acid-treating commercially available solder particles. It is preferable to control the thickness of the oxide film existing on the surface of the said solder particle by the said acid treatment. Examples of commercially available solder particles include "DS10" manufactured by Mitsui Metal Mining Co., Ltd., "ST-5" manufactured by Mitsui Metal Mining Co., Ltd., "ST-2" manufactured by Mitsui Metal Mining Co., Ltd., and the like. An organic acid etc. are mentioned as an acid used for the said acid treatment.

(Storage method of solder particles) The storage method of the solder particles of the present invention is preferably a method for storing the above-mentioned solder particles. It is preferable to store the said solder particle by the storage method of the solder particle of this invention. Preferably, the solder particles are stored in a storage container under an inert gas atmosphere, or the solder particles are stored in a storage container in a vacuum at 1×10 ² Pa or less.

From the viewpoint of more effectively improving the solder agglomeration at the time of conductive connection, the storage method of the above-mentioned solder particles may be refrigerated storage or frozen storage.

However, the solder particles of the present invention may be stored, for example, by placing the solder particles in a storage container at a temperature of 10° C. or higher and 50° C. or lower. The solder particles of the present invention can be stored at 10°C to 45°C, can be stored at 20°C or above, can be stored at 25°C or above, can be stored at 40°C or below, or can be stored at 30°C or below for safekeeping. The storage method of the above-mentioned solder particles is preferably storage below normal temperature, more preferably storage below normal temperature.

In order to store the said solder particle under the said temperature condition, a constant temperature bath etc. can be used. It is preferable to store the storage container containing the above-mentioned solder particles in a thermostat set to the above-mentioned preferable temperature conditions.

As for the storage method of the said solder particle, it is preferable to put the said solder particle into a storage container and store it in an inert gas atmosphere from a viewpoint of improving the solder aggregation property at the time of conductive connection more effectively.

Argon gas, nitrogen gas, etc. are mentioned as said inert gas.

From the viewpoint of more effectively improving the solder agglomeration at the time of conductive connection, it is preferable to store the above-mentioned solder particles in a storage container and vacuum the above-mentioned solder particles under the condition of 0.8×10 ² Pa or less. For storage, it is more preferable to carry out vacuum storage under the condition of 0.5×10 ² Pa or less.

In order to store the said solder particle under the said vacuum condition, it is preferable to depressurize and store the inside of the said storage container using a vacuum pump etc..

The above-mentioned storage container is not particularly limited as long as it is a container resistant to refrigerated storage, freezer storage, and vacuum storage. From the standpoint of more effectively improving solder aggregation during conductive connection, the above-mentioned storage container is preferably a container capable of preventing infiltration of oxygen, and is preferably a container with good airtightness. An aluminum bag etc. are mentioned as said storage container.

It is preferable to control the oxygen concentration in the above-mentioned storage container from the viewpoint of more effectively improving the solder aggregation property at the time of conductive connection. The oxygen concentration in the storage container is preferably 200 ppm or less, more preferably 100 ppm or less, from the viewpoint of more effectively improving solder aggregation at the time of conductive connection. As a method of controlling the oxygen concentration in the above-mentioned storage container, a method of replacing the inside of the above-mentioned storage container with nitrogen gas, etc. may be mentioned.

The oxygen concentration in the above-mentioned storage container can be obtained using an oxygen concentration meter. As an oxygen concentration meter, "XO-326IIsA" by New Cosmos Electric Co., Ltd. etc. are mentioned.

(Conductive material and method for producing conductive material) The conductive material of the present invention includes a thermosetting component and a plurality of solder particles. In the conductive material of the present invention, the solder particle has a solder particle body and an oxide film arranged on an outer surface of the solder particle body. In the conductive material of the present invention, the particle size of the above-mentioned solder particles is not less than 1 μm and not more than 15 μm. In the conductive material of the present invention, when the solder particles are heated at 120° C. for 10 hours in an air environment, the ratio of the average thickness of the oxide film before heating to the average thickness of the oxide film after heating is 2/3 the following.

The manufacturing method of the conductive material of this invention is equipped with the mixing process which mixes a thermosetting component and several solder particles, and obtains a conductive material. In the manufacturing method of the conductive material of this invention, the said solder particle has a solder particle main body, and the oxide film arrange|positioned on the outer surface of the said solder particle main body. In the manufacturing method of the conductive material of this invention, the particle diameter of the said solder particle is 1 micrometer or more and 15 micrometers or less. In the manufacturing method of the conductive material of the present invention, the following conductive material is obtained: when the above-mentioned solder particles are heated at 120° C. for 10 hours in an air environment, the average thickness of the above-mentioned oxide film before heating is compared with the average thickness of the oxide film after heating. The average thickness ratio is 2/3 or less.

In the conductive material of the present invention and the method for producing the conductive material of the present invention, solder particles are used. The above-mentioned solder particles are preferably the above-mentioned solder particles. The conductive material of the present invention and the method for producing the conductive material of the present invention preferably use the above-mentioned solder particles.

Since the conductive material of the present invention and the method for producing the conductive material of the present invention have the above configuration, it is possible to effectively improve the solder agglomeration at the time of conductive connection.

Compared with the conventional conductive material containing solder particles with a particle size of about 35 μm, the conductive material containing solder particles with a particle size of 10 μm or less has the following problem: the solder particles cannot be used for conductive connection. Coagulate efficiently between the upper and lower electrodes that should be connected. The inventors of the present invention have carried out diligent research in order to solve the above-mentioned problems, and found that the causes of the above-mentioned problems are: as the particle size of the solder particles becomes smaller, the oxide film existing on the surface of the solder particles becomes relatively thick; The increase of the surface area increases the content of the oxide film present on the surface of the solder particles. Furthermore, the inventors of the present invention conducted intensive studies to solve the above-mentioned problems, and as a result, found that the above-mentioned problems can be solved by controlling the oxide film existing on the surface of the solder particle to a specific thickness. In the present invention, although the particle size of the solder particles is reduced, the movement of the above-mentioned solder particles to the electrodes is sufficiently carried out, the solder can be efficiently aggregated between the electrodes to be connected, and the conduction reliability and insulation reliability can be improved. .

Also, in the present invention, since the solder particles can be efficiently agglomerated on the electrodes by controlling the oxide film existing on the surface of the solder particles to a specific thickness, it is not necessary to increase the content of the flux in the conductive material excessively. . As a result, the reaction between the thermosetting component in the conductive material and the flux can be effectively suppressed, and the storage stability of the conductive material can be effectively improved.

Also, there is a tendency that the melting point (activation temperature) of the flux in the conductive material is lower than the Tg of the thermosetting component in the conductive material in many cases, and the more the content of the flux in the conductive material becomes, the The heat resistance of the hardened conductive material decreases. Since the present invention does not need to excessively increase the flux content in the conductive material, it can effectively improve the heat resistance of the cured product of the conductive material. Moreover, since the present invention does not need to increase the content of flux in the conductive material excessively, it can effectively suppress the generation of voids in the cured product of the conductive material, and can effectively suppress the occurrence of poor hardening of the conductive material.

Since the present invention has the above structure, it can meet all the requirements of improving the solder aggregation property during conductive connection, improving the storage stability of the conductive material, and improving the heat resistance of the cured product of the conductive material.

In the present invention, in order to obtain the above effects, it is very helpful to control the oxide film existing on the surface of the solder particle to a specific thickness.

Furthermore, the present invention can prevent positional displacement between electrodes. In the present invention, when the second connection object member is superimposed on the first connection object member on which the conductive material is arranged on the upper surface, even if the alignment of the electrodes of the first connection object member and the electrodes of the second connection object member is shifted In this state, the offset can also be corrected to connect the electrodes (self-alignment effect).

From the standpoint of more effectively improving solder aggregation at the time of conductive connection, the above-mentioned conductive material is preferably liquid at 25° C., and is preferably a conductive paste.

From the viewpoint of more effectively improving the solder cohesion during conductive connection, the viscosity (η25(5 rpm)) of the above-mentioned conductive material at 25°C and 5 rpm is preferably 10 Pa·s or more, more preferably 30 Pa・s or more, more preferably 50 Pa・s or more, particularly preferably 100 Pa・s or more. From the viewpoint of more effectively improving the solder cohesion during conductive connection, the viscosity (η25(5 rpm)) of the above-mentioned conductive material under the conditions of 25°C and 5 rpm is preferably 600 Pa·s or less, more preferably 400 Pa·s or less, more preferably 300 Pa·s or less, still more preferably 250 Pa·s or less, particularly preferably 200 Pa·s or less. The above-mentioned viscosity (η25 (5 rpm)) can be adjusted appropriately according to the type and amount of the compounded ingredients.

The above-mentioned viscosity (η25 (5 rpm)) can be measured under conditions of 25°C and 5 rpm using, for example, an E-type viscometer ("TVE22L" manufactured by Toki Sangyo Co., Ltd.).

From the viewpoint of more effectively improving the solder cohesion during conductive connection, the viscosity (η20(5 rpm)) of the above-mentioned conductive material under the conditions of 20°C and 5 rpm is preferably 10 Pa·s or more, more preferably 30 Pa·s or more, and preferably 600 Pa·s or less, more preferably 400 Pa·s or less. The above-mentioned viscosity (η20(5 rpm)) can be adjusted appropriately according to the type and amount of compounded ingredients.

The above-mentioned viscosity (η20 (5 rpm)) can be measured under conditions of 20°C and 5 rpm using, for example, an E-type viscometer ("TVE22L" manufactured by Toki Sangyo Co., Ltd.).

From the point of view of more effectively improving the solder agglutination during conductive connection, the viscosity (η25 (0.5 rpm)) of the above-mentioned conductive material measured with an E-type viscometer at 25°C and 0.5 rpm is preferably 50 Pa·s or more, more preferably 100 Pa·s or more, and preferably 400 Pa·s or less, more preferably 300 Pa·s or less. The above-mentioned viscosity (η25 (0.5 rpm) can be adjusted appropriately according to the type and amount of the prepared ingredients.

From the point of view of more effectively improving the solder aggregation during conductive connection, the viscosity (η25(5 rpm)) of the above-mentioned conductive material measured by an E-type viscometer at 25°C and 5 rpm is preferably 50 Pa·s or more, more preferably 100 Pa·s or more, and preferably 250 Pa·s or less, more preferably 200 Pa·s or less. The above-mentioned viscosity (η25 (5 rpm)) can be adjusted appropriately according to the type and amount of the compounded ingredients.

As said E-type viscometer, Toki Sangyo Co., Ltd. make "TVE22L" etc. are mentioned.

The viscosity obtained by dividing the viscosity of the above-mentioned conductive material measured with an E-type viscometer at 25°C and 0.5 rpm by the viscosity of the above-mentioned conductive material measured with an E-type viscometer at 25°C and 5 rpm The variable index (η25(0.5 rpm)/η25(5 rpm)) is preferably at least 1.1, more preferably at least 1.5. The thixotropy obtained by dividing the viscosity of the above-mentioned conductive material measured with an E-type viscometer at 25°C and 0.5 rpm by the viscosity of the above-mentioned conductive material measured with an E-type viscometer at 25°C and 5 rpm The index (η25 (0.5 rpm)/η25 (5 rpm)) is preferably 5 or less, more preferably 4 or less, still more preferably 3 or less. When the above-mentioned thixotropic index (η25(0.5 rpm)/η25(5 rpm)) is more than the above-mentioned lower limit and not more than the above-mentioned upper limit, the solder agglomeration at the time of conductive connection can be improved more effectively.

The above-mentioned conductive material can be used as a conductive paste, a conductive film, and the like. The above-mentioned conductive paste is preferably an anisotropic conductive paste, and the above-mentioned conductive film is preferably an anisotropic conductive film. From the viewpoint of more effectively improving the solder aggregation property at the time of conductive connection, the above-mentioned conductive material is preferably a conductive paste. The above-mentioned conductive materials can be suitably used for electrical connection of electrodes. The above-mentioned conductive material is preferably a circuit connection material.

The manufacturing method of the conductive material of the present invention includes a mixing step of mixing a thermosetting component and a plurality of solder particles to obtain a conductive material. It is preferable that the manufacturing method of the electrically-conductive material of this invention further includes the storage process of storing the said solder particle. In the manufacturing method of the conductive material of this invention, it is preferable that the said storage process is the process of putting the said solder particle into a storage container and storing it in an inert gas atmosphere. In the manufacturing method of the conductive material of the present invention, the storage step is preferably a step of putting the solder particles in a storage container and vacuum storage under the condition of 1×10 ² Pa or less. In the manufacturing method of the conductive material of this invention, it is preferable that the said solder particle is the solder particle stored through the said storage process.

From the viewpoint of more effectively improving the solder agglomeration at the time of conductive connection, the storage method of the above-mentioned solder particles may be refrigerated storage or frozen storage.

However, the solder particles of the present invention may be stored, for example, by placing the solder particles in a storage container at a temperature of not less than 10°C and not more than 50°C. The solder particles of the present invention can be stored at 10°C to 45°C, can be stored at 20°C or above, can be stored at 25°C or above, can be stored at 40°C or below, or can be stored at 30°C or below for safekeeping. The storage method of the above-mentioned solder particles is preferably storage below normal temperature, more preferably storage below normal temperature.

In the manufacturing method of the conductive material of this invention, it is preferable that the said solder particle is the said solder particle. In the manufacturing method of the electrically-conductive material of this invention, the said solder particle may be the solder particle stored by the storage method of the said solder particle.

In the above-mentioned mixing step, the method of mixing the above-mentioned thermosetting component and the above-mentioned solder particles can use a conventionally known dispersion method and is not particularly limited. As a method of dispersing the said solder particle in the said thermosetting component, the following method is mentioned. A method of kneading and dispersing the above-mentioned solder particles with a planetary mixer or the like after adding the above-mentioned thermosetting components. A method in which the solder particles are uniformly dispersed in water or an organic solvent using a homogenizer or the like, then added to the thermosetting component, and kneaded by a planetary mixer or the like to disperse them. A method in which the above-mentioned thermosetting component is diluted with water or an organic solvent, and then the above-mentioned solder particles are added, kneaded and dispersed by a planetary mixer or the like.

In the mixing step, it is preferable to control the oxygen concentration so that the solder particles are not excessively oxidized from the viewpoint of more effectively improving the agglomeration of the solder at the time of conductive connection. As a method of controlling the above-mentioned oxygen concentration, a method of carrying out the above-mentioned mixing step in a nitrogen atmosphere, etc. may be mentioned. The oxygen concentration in the mixing step is preferably 200 ppm or less, more preferably 100 ppm or less, from the viewpoint of more effectively improving solder aggregation during conductive connection.

The oxygen concentration in the above mixing step can be determined using an oxygen concentration meter. As an oxygen concentration meter, "XO-326IIsA" by New Cosmos Electric Co., Ltd. etc. are mentioned.

In 100% by weight of the conductive material, the content of the solder particles is preferably at least 30% by weight, more preferably at least 50% by weight, and is preferably at most 80% by weight, more preferably at most 70% by weight. When content of the said solder particle is more than the said minimum and below the said upper limit, it becomes easy to arrange|position solder on an electrode more efficiently, and conduction reliability becomes high more effectively. From the viewpoint of improving conduction reliability more effectively, the content of the above-mentioned solder particles is preferably larger.

(How to store conductive materials) The storage method of the conductive material of the present invention is preferably a method for storing the above-mentioned conductive material. It is preferable to store the said electrically-conductive material by the storage method of the electrically-conductive material of this invention.

From the standpoint of more effectively improving the solder agglutination at the time of conductive connection, as for the storage method of the above-mentioned conductive material, it is preferable to put the above-mentioned conductive material in a storage container and store it under the condition of -40°C or higher and 10°C or lower. It is stored, or the above-mentioned conductive material is put into a storage container and stored under an inert gas atmosphere.

From the viewpoint of more effectively improving the solder coagulation property at the time of conductive connection, the storage method of the above-mentioned conductive material may be refrigerated storage or frozen storage.

However, the conductive material of the present invention can be stored at 10°C to 45°C, at 20°C or above, at 25°C or above, at 40°C or below, or at 30°C Save as follows. The conductive material of the present invention can be stored at -20°C or higher, -10°C or higher, and can be stored at 50°C or lower, or 10°C or lower. The storage method of the above-mentioned conductive materials is preferably storage below normal temperature, more preferably storage below normal temperature.

In order to store the above-mentioned conductive material under the above-mentioned temperature conditions, a refrigerator, a freezer, a constant temperature bath, and the like can be used. It is preferable to store the storage container containing the above-mentioned conductive material in a thermostat set to the above-mentioned preferable temperature conditions.

From the standpoint of more effectively improving solder aggregation during conductive connection, it is preferable to store the conductive material in a storage container under an inert gas atmosphere as a storage method for the conductive material.

Argon gas, nitrogen gas, etc. are mentioned as said inert gas.

From the standpoint of more effectively improving the solder agglutination at the time of conductive connection, as for the storage method of the above-mentioned conductive material, it is preferable to put the above-mentioned conductive material in a storage container and vacuum it under the condition of 0.8×10 ² Pa or less. For storage, it is more preferable to carry out vacuum storage under the condition of 0.5×10 ² Pa or less.

In order to store the said electrically-conductive material under the said vacuum condition, it is preferable to depressurize and store the inside of the said storage container using a vacuum pump etc..

The above-mentioned storage container is not particularly limited as long as it is a container resistant to refrigeration storage and freezer storage. From the standpoint of more effectively improving solder aggregation during conductive connection, the above-mentioned storage container is preferably a container capable of preventing infiltration of oxygen, and is preferably a container with good airtightness. An aluminum bag etc. are mentioned as said storage container.

It is preferable to control the oxygen concentration in the above-mentioned storage container from the viewpoint of more effectively improving the solder aggregation property at the time of conductive connection. The oxygen concentration in the storage container is preferably 200 ppm or less, more preferably 100 ppm or less, from the viewpoint of more effectively improving solder aggregation at the time of conductive connection. As a method of controlling the oxygen concentration in the above-mentioned storage container, a method of replacing the inside of the above-mentioned storage container with nitrogen gas, etc. may be mentioned.

The oxygen concentration in the above-mentioned storage container can be obtained using an oxygen concentration meter. As an oxygen concentration meter, "XO-326IIsA" by New Cosmos Electric Co., Ltd. etc. are mentioned.

Other details of the conductive material will be described below.

(thermosetting components) The above-mentioned thermosetting component is not particularly limited. The above-mentioned thermosetting component may contain a thermosetting compound curable by heating, and a thermosetting agent.

(thermosetting component: thermosetting compound) Examples of the thermosetting compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth)acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, Ester compounds, polysiloxane compounds and polyimide compounds, etc. In terms of making the hardening and viscosity of the conductive material better, improving the conduction reliability more effectively, and improving the insulation reliability more effectively, epoxy compounds or episulfide compounds are preferred, and more Epoxy compounds are preferred. It is preferable that the said thermosetting component contains an epoxy compound. It is preferable that the said thermosetting component contains an epoxy compound and a hardening|curing agent. The said thermosetting component may use only 1 type, and may use 2 or more types together.

The above-mentioned epoxy compound is a compound having at least one epoxy group. Examples of the epoxy compounds include bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol S epoxy compounds, phenol novolac epoxy compounds, biphenyl epoxy compounds, and biphenyl epoxy compounds. Novolak type epoxy compound, biphenol type epoxy compound, resorcinol type epoxy compound, naphthalene type epoxy compound, fennel type epoxy compound, benzophenone type epoxy compound, phenol aralkyl type Epoxy compounds, naphthol aralkyl type epoxy compounds, dicyclopentadiene type epoxy compounds, anthracene type epoxy compounds, epoxy compounds with adamantane skeleton, epoxy compounds with tricyclodecane skeleton, Naphthyl ether-type epoxy compounds, and epoxy compounds having a three-core nucleus in the skeleton, etc. The said epoxy compound may use only 1 type, and may use 2 or more types together.

As the above-mentioned epoxy compound, aromatic epoxy compounds such as resorcinol type epoxy compound, naphthalene type epoxy compound, biphenyl type epoxy compound, benzophenone type epoxy compound and phenol novolac type epoxy compound are preferable. family of epoxy compounds. The melting temperature of the epoxy compound is preferably not higher than the melting point of solder. The melting temperature of the epoxy compound is preferably not higher than 100°C, more preferably not higher than 80°C, further preferably not higher than 40°C. By using the above-mentioned preferred epoxy compound, the viscosity is high at the stage of laminating the members to be connected, and when the acceleration is given due to the impact of transportation, etc., the positions of the first member to be connected and the second member to be connected can be suppressed offset. Furthermore, the viscosity can be greatly reduced by the heat during hardening, and the solder agglomeration at the time of conductive connection can be improved more effectively.

From the viewpoint of more effectively improving the heat resistance of the cured product, the thermosetting component preferably contains a thermosetting compound having an isocyanuric acid skeleton.

Examples of the above-mentioned thermosetting compound having an isocyanuric acid skeleton include triisocyanurate-type epoxy compounds and the like, such as the TEPIC series (TEPIC-G, TEPIC-S, TEPIC- SS, TEPIC-HP, TEPIC-L, TEPIC-PAS, TEPIC-VL, TEPIC-UC), etc.

In 100% by weight of the conductive material, the content of the thermosetting compound is preferably at least 20% by weight, more preferably at least 40% by weight, further preferably at least 50% by weight, and more preferably at most 99% by weight. It is 98% by weight or less, more preferably 90% by weight or less, especially preferably 80% by weight or less. When the content of the thermosetting compound is not less than the above-mentioned lower limit and not more than the above-mentioned upper limit, the agglomeration of solder during conductive connection can be more effectively improved, and the heat resistance of the cured product of the conductive material can be more effectively improved. From the viewpoint of improving impact resistance more effectively, it is preferable that there is a large content of the above-mentioned thermosetting compound.

In 100% by weight of the conductive material, the content of the above-mentioned epoxy compound is preferably at least 20% by weight, more preferably at least 40% by weight, further preferably at least 50% by weight, and is preferably at most 99% by weight, more preferably at least 99% by weight. 98% by weight or less, more preferably 90% by weight or less, particularly preferably 80% by weight or less. When the content of the epoxy compound is not less than the above lower limit and not more than the above upper limit, it is possible to more effectively improve the solder agglomeration at the time of conductive connection, and to more effectively improve the heat resistance of the cured product of the conductive material. From the viewpoint of further improving impact resistance, it is preferable that the content of the above-mentioned epoxy compound is large.

(thermosetting component: thermosetting agent) The above-mentioned thermosetting agent is not particularly limited. The thermosetting agent thermosets the thermosetting compound. Examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents and other mercaptan curing agents, phosphonium salts, acid anhydride curing agents, thermal cationic initiators (thermal cationic curing agents), and Thermal free radical generators, etc. The said thermosetting agent may use only 1 type, and may use 2 or more types together.

From the viewpoint of enabling the conductive material to harden more rapidly at low temperature, the above-mentioned thermosetting agent is preferably an imidazole curing agent, a mercaptan curing agent, or an amine curing agent. Moreover, it is preferable that the said thermosetting agent is a latent thermosetting agent from a viewpoint of improving the storage stability at the time of mixing the said thermosetting compound and the said thermosetting agent. The latent thermal curing agent is preferably a latent imidazole curing agent, a latent mercaptan curing agent or a latent amine curing agent. Furthermore, the above-mentioned thermosetting agent may be coated with a polymer substance such as polyurethane resin or polyester resin.

The above-mentioned imidazole curing agent is not particularly limited. Examples of the imidazole curing agent include: 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium Trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-trimethalinate and 2,4-diamino-6-[2' -Methylimidazolyl-(1')]-Ethyl-S-3-Isocyanuric Acid Adduct, 2-Phenyl-4,5-Dihydroxymethylimidazole, 2-Phenyl-4-Methyl -5-dihydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2-p-tolyl-4-methyl-5-hydroxymethylimidazole, 2-m-tolyl- 4-methyl-5-hydroxymethylimidazole, 2-m-tolyl-4,5-dihydroxymethylimidazole, 2-p-tolyl-4,5-dihydroxymethylimidazole, etc. An imidazole compound in which the hydrogen at the 5-position is substituted with a hydroxymethyl group and the hydrogen at the 2-position is substituted with a phenyl or tolyl group.

The above-mentioned mercaptan curing agent is not particularly limited. Examples of the mercaptan curing agent include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate.

The aforementioned amine hardener is not particularly limited. Examples of the amine hardener include hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis(3-aminopropyl)-2,4,8, 10-tetraspiro[5.5]undecane, bis(4-aminocyclohexyl)methane, m-phenylenediamine and diaminodiphenylene, etc.

The above-mentioned phosphonium salt is not particularly limited. Examples of the above-mentioned phosphonium salts include: tetra-n-butylphosphonium bromide, tetra-n-butylphosphonium O-O diethyldithiophosphate, methyltributylphosphonium dimethylphosphate, tetra-n-butylphosphonium benzo Triazole, tetra-n-butylphosphonium tetrafluoroborate, tetra-n-butylphosphonium tetraphenylborate, etc.

The above-mentioned acid anhydride curing agent is not particularly limited, and can be widely used as long as it is an acid anhydride used as a curing agent for thermosetting compounds such as epoxy compounds. Examples of the acid anhydride curing agent include: phthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride Acid anhydride, methyltetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, anhydride of phthalic acid derivatives, maleic anhydride, cyanide anhydride, methyl cyanide anhydride, Bifunctional anhydride hardeners such as glutaric anhydride, succinic anhydride, glycerin bis-trimellitic anhydride monoacetate, and ethylene glycol bis-trimellitic anhydride, trifunctional anhydride hardeners such as trimellitic anhydride, and benzene Tetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, methylcyclohexene tetracarboxylic anhydride, polyazelaic anhydride and other tetrafunctional or higher anhydride hardeners.

系陽離子硬化劑及鋶系陽離子硬化劑等。作為上述錪系陽離子硬化劑，可列舉雙(4-第三丁基苯基)錪六氟磷酸鹽等。作為上述

系陽離子硬化劑，可列舉三甲基

四氟硼酸鹽等。作為上述鋶系陽離子硬化劑，可列舉三-對甲苯基鋶六氟磷酸鹽等。The aforementioned thermal cationic starter (thermal cationic curing agent) is not particularly limited. Examples of the thermal cationic initiator (thermal cationic curing agent) include iodonium-based cationic curing agents,

It is a cationic hardener and a cerium series cationic hardener, etc. Bis(4-tert-butylphenyl)iodonium hexafluorophosphate etc. are mentioned as said iodonium type cationic hardening agent. as above

It is a cationic hardener, such as trimethyl

Tetrafluoroborate etc. Tris-p-tolyl percite hexafluorophosphate etc. are mentioned as said permeicium type cationic hardening agent.

The aforementioned thermal radical generating agent is not particularly limited. As said thermal radical generating agent, an azo compound, an organic peroxide, etc. are mentioned. As said azo compound, azobisisobutyronitrile (AIBN) etc. are mentioned. Examples of the organic peroxide include di-tert-butyl peroxide, methyl ethyl ketone peroxide, and the like.

The reaction initiation temperature of the above thermosetting agent is preferably at least 50°C, more preferably at least 70°C, still more preferably at least 80°C, and preferably at most 250°C, more preferably at most 200°C, and still more preferably at least 200°C. Below 150°C, especially preferably below 140°C. Solder can be more efficiently arrange|positioned on an electrode as the reaction start temperature of the said thermosetting agent is more than the said minimum and below the said upper limit. The reaction initiation temperature of the above-mentioned thermosetting agent is more preferably 80° C. or higher and 140° C. or lower.

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

The reaction initiation temperature of the above-mentioned thermosetting agent means the temperature at which the rise of the exothermic peak in DSC begins.

The content of the above-mentioned thermosetting agent is not particularly limited. With respect to 100 parts by weight of the above-mentioned thermosetting compound, the content of the above-mentioned thermosetting agent is preferably at least 0.01 parts by weight, more preferably at least 1 part by weight, and is preferably at most 200 parts by weight, more preferably at most 100 parts by weight, Furthermore, it is more preferably 75 parts by weight or less. If content of a thermosetting agent is more than the said minimum, it will become easy to fully harden a conductive material. If the content of the thermosetting agent is not more than the above upper limit, it will be difficult for the excess thermosetting agent not participating in the curing to remain after curing, and the heat resistance of the cured product will further increase.

(flux) The above-mentioned conductive material may contain flux. By using the flux, it is possible to more efficiently arrange the solder on the electrodes. The aforementioned flux is not particularly limited. As the above-mentioned flux, fluxes generally used for solder bonding and the like can be used.

Examples of the aforementioned fluxes include zinc chloride, mixtures of zinc chloride and inorganic halides, mixtures of zinc chloride and inorganic acids, molten salts, phosphoric acid, derivatives of phosphoric acid, organic halides, hydrazine, amine compounds, organic Acid and turpentine etc. The above fluxes may be used alone or in combination of two or more.

Ammonium chloride etc. are mentioned as said molten salt. Lactic acid, citric acid, stearic acid, glutamic acid, glutaric acid, etc. are mentioned as said organic acid. As said rosin, activated rosin, non-activated rosin, etc. are mentioned. The aforementioned flux is preferably an organic acid having two or more carboxyl groups, or rosin. The above-mentioned flux may be an organic acid having two or more carboxyl groups, or may be rosin. By using an organic acid having two or more carboxyl groups and rosin, the conduction reliability between electrodes is further improved.

Examples of the organic acid having two or more carboxyl groups include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

Examples of the amine compound include cyclohexylamine, dicyclohexylamine, benzylamine, benzhydrylamine, imidazole, benzimidazole, phenylimidazole, carboxybenzimidazole, benzotriazole, and carboxybenzotriazole azole etc.

The above-mentioned rosin is a rosin mainly composed of abietic acid. Examples of the aforementioned rosins include abietic acid, acrylic-modified rosins, and the like. The flux is preferably rosin, more preferably rosin acid. With the use of this preferred flux, the conduction reliability between electrodes is further improved.

The activation temperature (melting point) of the above flux is preferably above 50°C, more preferably above 70°C, further preferably above 80°C, and preferably below 200°C, more preferably below 190°C, and more preferably below 190°C. 160°C or lower, more preferably 150°C or lower, still more preferably 140°C or lower. If the activation temperature of the above-mentioned flux is more than the above-mentioned lower limit and not more than the above-mentioned upper limit, the effect of the flux can be exhibited more effectively, and the solder can be more uniformly arranged on the electrodes. The activation temperature (melting point) of the above flux is preferably not less than 80°C and not more than 190°C. The activation temperature (melting point) of the above-mentioned flux is more preferably 80°C or more and 140°C or less.

Examples of the above-mentioned fluxes whose activation temperature (melting point) of the flux is 80°C to 190°C include: succinic acid (melting point 186°C), glutaric acid (melting point 96°C), adipic acid (melting point 152°C) Dicarboxylic acids such as pimelic acid (melting point 104°C), suberic acid (melting point 142°C), benzoic acid (melting point 122°C), malic acid (melting point 130°C), etc.

In addition, the boiling point of the above-mentioned flux is preferably 200° C. or lower.

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

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

The above-mentioned flux can be dispersed in the conductive material, and can also be attached to the surface of the above-mentioned solder particles.

Since the melting point of the flux is higher than that of the solder, the solder particles can be efficiently aggregated on the electrode portion. The reason for this is that when heat is applied during bonding, if the electrode formed on the connection partner member is compared with the part of the connection partner member around the electrode, the thermal conductivity of the electrode part is higher than that of the connection partner member around the electrode. Partial thermal conductivity, so that the temperature of the electrode part rises faster. At the stage exceeding the melting point of the solder particles, the inside of the solder particles will dissolve, but the oxide film formed on the surface does not reach the melting point (activation temperature) of the flux, so it will not be removed. In this state, the temperature of the electrode portion first reaches the melting point of the flux (activation temperature), so the oxide film on the surface of the solder particles moving to the electrode is preferentially removed, and the solder particles can wet and diffuse to the surface of the electrode. Thereby, solder particles can be efficiently aggregated on the electrodes.

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

Examples of the flux that releases cations by heating include the aforementioned thermal cation initiators (thermal cation curing agents).

From the viewpoints of disposing solder on the electrodes more efficiently, improving insulation reliability more effectively, and improving conduction reliability more effectively, the above-mentioned flux is preferably a salt of an acid compound and an alkali compound. .

The above-mentioned acid compound is preferably an organic compound having a carboxyl group. Examples of the acid compound include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, citric acid, and malic acid, which are aliphatic carboxylic acids. , Cyclohexyl carboxylic acid, 1,4-cyclohexyl dicarboxylic acid as cycloaliphatic carboxylic acid, isophthalic acid, terephthalic acid, trimellitic acid, and ethylenediamine tetracarboxylic acid as aromatic carboxylic acid Acetic acid etc. From the viewpoints of disposing the solder on the electrodes more efficiently, improving the insulation reliability more effectively, and improving the conduction reliability more effectively, the above-mentioned acid compound is preferably glutaric acid, cyclohexyl carboxyl acid, or adipic acid.

The above-mentioned base compound is preferably an organic compound having an amino group. Examples of the base compound include: diethanolamine, triethanolamine, methyldiethanolamine, ethyldiethanolamine, cyclohexylamine, dicyclohexylamine, benzylamine, benzhydrylamine, 2-methylbenzylamine, 3- Methylbenzylamine, 4-tert-butylbenzylamine, N-methylbenzylamine, N-ethylbenzylamine, N-phenylbenzylamine, N-tert-butylbenzylamine, N-isopropylbenzylamine Amines, N,N-dimethylbenzylamine, imidazole compounds, and triazole compounds. The alkali compound is preferably benzylamine from the viewpoints of more efficiently disposing solder on the electrodes, more effectively improving insulation reliability, and more effectively improving conduction reliability.

In 100% by weight of the conductive material, the content of the above flux is preferably not less than 0.5% by weight, and preferably not more than 30% by weight, more preferably not more than 25% by weight. The above-mentioned conductive material may contain flux. If the content of the above-mentioned flux is more than the above-mentioned lower limit and below the above-mentioned upper limit, the oxide film is less likely to be formed 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.

(filler) The conductive material of the present invention may contain fillers. Fillers can be organic fillers or inorganic fillers. Since the above-mentioned conductive material contains the filler, the solder can be uniformly agglomerated on the entire electrode of the substrate.

The above-mentioned conductive material preferably does not contain the above-mentioned filler, or contains the above-mentioned filler at 5% by weight or less. In the case of using the above-mentioned thermosetting compound, the smaller the content of the filler, the easier it is for the solder to move to the electrode.

In 100% by weight of the conductive material, the content of the filler is preferably 0% by weight (not contained), and preferably 5% by weight or less, more preferably 2% by weight or less, and more preferably 1% by weight or less. Solder can be more efficiently arrange|positioned on an electrode as content of the said filler is more than the said minimum and below the said upper limit.

(other ingredients) The above-mentioned conductive materials may also include, for example, fillers, extenders, softeners, plasticizers, thixotropic agents, leveling agents, polymerization catalysts, hardening catalysts, colorants, antioxidants, heat stabilizers, light stabilizers, etc. additives, UV absorbers, lubricants, antistatic agents and flame retardants.

(Connection structure and method of manufacturing the connection structure) The connection structure of the present invention includes: a first connection object member having a first electrode on its surface, a second connection object member having a second electrode on its surface, and a connection portion connecting the first connection object member and the second connection object member . In the connection structure of this invention, the material of the said connection part contains the said solder particle. In the connection structure of this invention, the material of the said connection part is the said conductive material. In the connection structure of this invention, the said 1st electrode and the said 2nd electrode are electrically connected by the solder part in the said connection part.

The method for manufacturing a connection structure of the present invention includes the step of disposing the conductive material on the surface of the first connection object member having the first electrode on the surface using the conductive material containing the solder particles or the conductive material. The manufacturing method of the connection structure of the present invention includes the following steps: arranging a second connection object member having a second electrode on its surface on the conductive material and the first connection member in such a manner that the first electrode and the second electrode face each other. On the surface opposite to the object component side. The method for manufacturing a connection structure according to the present invention includes the step of forming a connection portion connecting the first connection object member and the second connection object member from the above-mentioned conductive material by heating the above-mentioned conductive material to a temperature above the melting point of the solder particles. , and electrically connect the first electrode and the second electrode through the solder portion in the connection portion.

In the connection structure and the method of manufacturing the connection structure of the present invention, since specific solder particles or specific conductive materials are used, the solder particles can be efficiently arranged on the electrodes and easily gathered on the first electrode and the second electrode In between, the solder particles can be efficiently aggregated on the electrodes (wires). In addition, part of the solder particles is less likely to be placed in the region (gap) where no electrode is formed, and the amount of solder particles placed in the region where no electrode is formed can be greatly reduced. Therefore, the conduction reliability between the first electrode and the second electrode can be improved. Furthermore, it is possible to prevent electrical connection between laterally adjacent electrodes that cannot be connected, and to improve insulation reliability.

In addition, in order to efficiently arrange solder on the electrodes and greatly reduce the amount of solder disposed on the regions where electrodes are not formed, it is preferable to use a conductive paste instead of a conductive film as the above-mentioned conductive material.

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

In the method for manufacturing a connection structure according to the present invention, it is preferable not to apply pressure in the step of arranging the second connection object member and the step of forming the connection portion, but to apply the second connection object member to the above-mentioned conductive material. weight. In the method for manufacturing a connection structure of the present invention, it is preferable not to apply a force exceeding the weight of the second connection object member to the conductive material in the step of arranging the second connection object member and the above step of forming the connection portion. pressurized pressure. In these cases, the uniformity of the amount of solder can be further improved in a plurality of solder portions. Furthermore, the thickness of the solder portion can be increased more effectively, a large number of solder particles tend to gather between the electrodes, and the plurality of solder particles can be more efficiently arranged on the electrodes (lines). In addition, part of the plurality of solder particles is less likely to be placed in the region (gap) where no electrodes are formed, and the amount of solder in the solder particles placed in the region where no electrodes are formed can be further reduced. Therefore, the conduction reliability between electrodes can be further improved. Furthermore, it is possible to prevent electrical connection between laterally adjacent electrodes that cannot be connected, and further improve insulation reliability.

Also, if a conductive paste is used instead of a conductive film, it is easy to adjust the thickness of the connection portion and the solder portion by the amount of the conductive paste applied. On the other hand, the conductive film has a problem that in order to change or adjust the thickness of the connection portion, it is necessary to prepare conductive films of different thicknesses or to prepare conductive films of a specific thickness. In addition, the conductive film tends not to sufficiently reduce the melt viscosity of the conductive film at the melting temperature of the solder compared with the conductive paste, and tends to hinder the aggregation of solder particles.

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

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

The connection structure 1 shown in FIG. 1 is provided with the 1st connection object member 2, the 2nd connection object member 3, and the connection part 4 which connects the 1st connection object member 2 and the 2nd connection object member 3. As shown in FIG. The connecting portion 4 is formed of the above-mentioned conductive material. In the present embodiment, the conductive material includes a thermosetting compound, a thermosetting agent, and solder particles. In this embodiment, conductive paste is used as the conductive material.

The connecting portion 4 has a solder portion 4A in which a plurality of solder particles are gathered and bonded to each other, and a hardened portion 4B in which a thermosetting compound is thermally cured.

The 1st connection object member 2 has the some 1st electrode 2a on the surface (upper surface). The 2nd connection object member 3 has the some 2nd electrode 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, there are no solder particles in a region (hardened part 4B part) different from the solder part 4A gathered between the first electrode 2a and the second electrode 3a. In a region different from the solder portion 4A (hardened portion 4B portion), there are no solder particles separated from the solder portion 4A. Furthermore, if there is a small amount, solder particles may exist in a region (cured part 4B part) different from the solder part 4A gathered between the first electrode 2a and the second electrode 3a.

As shown in FIG. 1, in the connection structure 1, a plurality of solder particles gather between the first electrode 2a and the second electrode 3a, and after the plurality of solder particles are melted, the molten material of the solder particles wets the surface of the electrode. Diffusion followed by solidification to form the solder portion 4A. Therefore, the connection area between 4 A of solder parts and the 1st electrode 2a, and 4 A of solder parts and the 2nd electrode 3a becomes large. That is, by using solder particles, the solder portion 4A and the first electrode 2a, and the solder portion 4A and the second electrode 3a are more stable than when using conductive particles whose outer conductive surface is metal such as nickel, gold, or copper. The contact area becomes larger. In this case, the conduction reliability and connection reliability of the connection structure 1 are also improved. Furthermore, when flux is included in the conductive material, the flux is usually gradually deactivated by heating.

In addition, in the connection structure 1 shown in FIG. 1, the whole solder part 4A is located in the area|region which opposes between 1st, 2nd electrode 2a, 3a. About the connection structure 1X of the modification shown in FIG. 3, only the connection part 4X is different from the connection structure 1 shown in FIG. The connecting portion 4X has a solder portion 4XA and a cured portion 4XB. Like the connection structure 1X, most of the solder portion 4XA is located in the area where the first and second electrodes 2a and 3a face each other, and a part of the solder portion 4XA is located in the area where the first and second electrodes 2a and 3a face each other. Spills to the side. The solder portion 4XA that overflows to the side from the opposing region of the first and second electrodes 2a, 3a is a part of the solder portion 4XA, and is not a solder particle separated from the solder portion 4XA. Furthermore, in the present embodiment, the amount of solder particles separated from the solder portion can be reduced, and the solder particles separated from the solder portion can also exist in the cured product portion.

If the amount of solder particles used is reduced, the connection structure 1 can be easily obtained. When the usage-amount of a solder particle increases, it becomes easy to obtain connection structure 1X.

In the connection structure 1, 1X, it is preferable that only the parts of the first electrode 2a and the second electrode 3a facing each other are observed in the lamination direction of the first electrode 2a, the connection part 4, 4X, and the second electrode 3a. The solder portions 4A, 4XA among the connecting portions 4, 4X are disposed on more than 50% of 100% of the areas of the portions facing each other between the first electrode 2a and the second electrode 3a. Since the solder portions 4A, 4XA in the connection portions 4, 4X satisfy the above-mentioned preferred aspects, the conduction reliability can be further improved.

When only the parts of the first electrode and the second electrode facing each other are observed in the stacking direction of the first electrode, the connecting portion, and the second electrode, it is preferable that the first electrode and the second electrode More than 50% of 100% of the area of the portions facing each other of the electrodes are provided with the solder portion in the connection portion. When only the parts of the first electrode and the second electrode facing each other are observed in the layering direction of the first electrode, the connecting portion, and the second electrode, it is more preferable that the first electrode and the second electrode More than 60% of 100% of the area of the portions of the electrodes facing each other is provided with the solder portion in the connection portion. When only the portions of the first electrode and the second electrode facing each other are observed in the stacking direction of the first electrode, the connection portion, and the second electrode, it is more preferable that the first electrode and the second electrode 2. More than 70% of 100% of the area of the parts facing each other of the electrodes are provided with the solder part in the above-mentioned connecting part. When only the parts of the first electrode and the second electrode facing each other are observed in the stacking direction of the first electrode, the connecting portion, and the second electrode, it is particularly preferable that the first electrode and the second electrode More than 80% of 100% of the area of the portions facing each other of the electrodes are provided with the solder portion in the connection portion. When only the portions of the first electrode and the second electrode facing each other are observed in the stacking direction of the first electrode, the connection portion, and the second electrode, it is preferable to place the first electrode and the second electrode on the opposite side. More than 90% of 100% of the area of the portions facing each other of the electrodes are provided with the solder portion in the connection portion. The conduction reliability can be further improved because the solder portion in the above-mentioned connecting portion satisfies the above-mentioned preferred aspect.

When only a portion of the first electrode and the second electrode facing each other is observed in a direction perpendicular to the stacking direction of the first electrode, the connection portion, and the second electrode, it is preferable that the At least 60% of the solder portion of the connection portion is arranged at the portion where the electrode and the second electrode face each other. When only a portion of the first electrode and the second electrode facing each other is observed in a direction perpendicular to the stacking direction of the first electrode, the connection portion, and the second electrode, it is more preferable that the first electrode More than 70% of the solder portion of the connection portion is arranged at the portion where the electrode and the second electrode face each other. When only a portion of the first electrode and the second electrode facing each other is observed in a direction perpendicular to the stacking direction of the first electrode, the connection portion, and the second electrode, it is more preferable that More than 90% of the solder portion of the connection portion is arranged at the portion where the first electrode and the second electrode face each other. When only a portion of the first electrode and the second electrode facing each other is observed in a direction perpendicular to the stacking direction of the first electrode, the connection portion, and the second electrode, it is particularly preferable that More than 95% of the solder portion of the connection portion is arranged at the portion where the electrode and the second electrode face each other. When only a portion of the first electrode and the second electrode facing each other is observed in a direction perpendicular to the lamination direction of the first electrode, the connection portion, and the second electrode, it is preferable that More than 99% of the solder portion of the connection portion is arranged at the portion where the electrode and the second electrode face each other. The conduction reliability can be further improved because the solder portion in the above-mentioned connecting portion satisfies the above-mentioned preferred aspect.

Next, an example of the method of manufacturing the connection structure 1 using the electrically-conductive material which concerns on one Embodiment of this invention is demonstrated with FIG. 2. FIG.

First, the 1st connection object member 2 which has the 1st electrode 2a on the surface (upper surface) is prepared. Next, as shown in FIG. 2( a ), conductive material 11 including thermosetting component 11B and a plurality of solder particles 11A is arranged on the surface of first connection object member 2 (first step). The conductive material 11 used contains a thermosetting compound and a thermosetting agent as a thermosetting component 11B.

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

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

Moreover, the 2nd connection object member 3 which has the 2nd electrode 3a on the surface (lower surface) is prepared. Then, as shown in FIG. 2( b), in 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 opposite to the first connection object member 2 side. Object member 3 (step 2). On the surface of the conductive material 11, the 2nd connection object member 3 is arrange|positioned from the 2nd electrode 3a side. At this time, the 1st electrode 2a and the 2nd electrode 3a are made to oppose.

Next, the conductive material 11 is heated to a temperature equal to or higher than the melting point of the solder particles 11A (third step). It is preferable to heat the conductive material 11 above the hardening temperature of the thermosetting component 11B (thermosetting compound). At the time of this heating, 11 A of solder particles which exist in the area|region where an electrode is not formed gather between the 1st electrode 2a and the 2nd electrode 3a (self-aggregation effect). When using a conductive paste instead of a conductive film, the solder particles 11A are more effectively gathered between the first electrode 2a and the second electrode 3a. Also, the solder particles 11A are melted and bonded to each other. Also, the thermosetting component 11B is thermally cured. As a result, as shown in FIG. 2( c ), the connection portion 4 connecting the first connection object member 2 and the second connection object member 3 is formed of the conductive material 11 . The connecting part 4 is formed by the conductive material 11, the solder part 4A is formed by bonding the plurality of solder particles 11A, and the cured part 4B is formed by thermosetting the thermosetting component 11B. If the solder particle 11A moves sufficiently, the movement of the solder particle 11A not located between the first electrode 2a and the second electrode 3a starts until the movement of the solder particle 11A between the first electrode 2a and the second electrode 3a is completed. The temperature may not be kept constant.

In this embodiment, it is preferable not to pressurize in the said 2nd process and the said 3rd process. In this case, the weight of the second connection object member 3 is applied to the conductive material 11 . Therefore, at the time of formation of the connection part 4, 11 A of solder particles gather more effectively between the 1st electrode 2a and the 2nd electrode 3a. Furthermore, if the pressure is applied in at least one of the above-mentioned second step and the above-mentioned third step, the tendency to hinder the action of gathering the solder particles 11A between the first electrode 2a and the second electrode 3a will be changed. high.

Also, in this embodiment, since no pressure is applied, even if the first connection object member 2 and the second connection object member 3 are overlapped in a state where the alignment of the first electrode 2a and the second electrode 3a is shifted, In some cases, the offset can be corrected to connect the first electrode 2a and the second electrode 3a (self-alignment effect). The reason for this is that the contact area between the self-agglutinated molten solder between the first electrode 2a and the second electrode 3a and other components such as solder and conductive materials between the first electrode 2a and the second electrode 3a becomes the smallest. The energy will be stable, so the force applied to the connection structure that becomes the smallest area, that is, the connection structure that achieves alignment, will act. At this time, it is preferable that the conductive material is not hardened, and that the viscosity of the components of the conductive material other than the solder particles is sufficiently low under the temperature and time conditions.

The viscosity (ηmp) of the conductive material at the melting point of the solder particles is preferably at most 50 Pa·s, more preferably at most 10 Pa·s, further preferably at most 1 Pa·s, and more preferably at least 0.1 Pa·s , more preferably 0.2 Pa·s or more. Solder particles can be aggregated efficiently that the said viscosity (ηmp) is below the said upper limit. When the said viscosity (ηmp) is more than the said minimum, the space|gap in a connection part can be suppressed, and the overflow of a conductive material outside a connection part can be suppressed.

The above-mentioned viscosity (ηmp) of the conductive material at the melting point of the solder particles can be controlled using STRESSTECH (manufactured by Reologica Co., Ltd.) with a strain of 1 rad, a frequency of 1 Hz, a heating rate of 20°C/min, and a measurement temperature range of 25 to 200°C (wherein, When the melting point of the solder particles exceeds 200° C., the upper limit of the temperature is defined as the melting point of the solder particles). Based on the measurement results, the viscosity at the melting point (°C) of the solder particles was evaluated.

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

The heating temperature in the third step is preferably at least 140°C, more preferably at least 160°C, more preferably at most 450°C, more preferably at most 250°C, even more preferably at most 200°C.

As the heating method in the above-mentioned third step, there may be mentioned a method of heating the entire connection structure to a temperature above the melting point of the solder particles and above the hardening temperature of the thermosetting component by using a reflow furnace or an oven, or by heating only the connection structure. A method of locally heating the connecting portion.

As an instrument used for the method of local heating, a hot plate, a heat gun for applying hot air, a soldering iron, an infrared heater, and the like may be mentioned.

Also, when heating locally with a heating plate, it is preferable to use a metal with high thermal conductivity directly below the connection to form the upper surface of the heating plate, and to use a material with low thermal conductivity such as fluororesin to form a heating plate for other parts that are not suitable for heating. upper surface.

The above-mentioned first and second connection object members are not particularly limited. As the above-mentioned first and second connection object members, specifically, semiconductor chips, semiconductor packages, LED (Light Emitting Diode, light emitting diode) chips, LED packages, electronic components such as capacitors and diodes, and resin Films, printed circuit boards, flexible printed circuit boards, flexible flat cables, rigid flexible substrates, glass epoxy resin substrates, glass substrates and other circuit substrates, etc. Electronic parts, etc. It is preferable that the said 1st, 2nd connection object member is an electronic component.

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 substrate. Preferably, the second connection object member is a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate. Resin films, flexible printed substrates, flexible flat cables, and rigid-flexible substrates are highly flexible and relatively lightweight. When a conductive film is used for the connection of such connection target members, there is a tendency that solder particles are less likely to gather on the electrodes. On the other hand, by using a conductive paste, even if a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate is used, the solder particles can be efficiently gathered on the electrodes, thereby sufficiently improving the conduction between the electrodes. reliability. When using a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate, it is more effective to obtain conduction between electrodes without applying pressure than when using other connection target members such as semiconductor chips. Improvement of reliability.

Metals such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes, SUS (Steel Use Stainless, Japanese Stainless Steel Standard) electrodes, and tungsten electrodes are examples of the electrodes provided on the above-mentioned member to be connected. electrode. When the above-mentioned member to be connected is a flexible printed circuit board, the above-mentioned electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode or a copper electrode. When the member to be connected is a glass substrate, 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 formed by laminating an aluminum layer on the surface of a metal oxide layer. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element, zinc oxide doped with a trivalent metal element, and the like. Sn, Al, Ga, etc. are mentioned as said trivalent metal element.

In the connection structure of the present invention, it is preferable that the first electrode and the second electrode are arranged in an area array or peripherally. When the above-mentioned first electrode and the above-mentioned second electrode are arranged in an area array or an external device, the effect of the present invention can be exhibited more effectively. The above-mentioned planar array is a structure in which electrodes are arranged in a lattice form on the surface where electrodes are arranged on the member to be connected. The above-mentioned peripheral device refers to a structure in which electrodes are arranged on the outer peripheral portion of the member to be connected. In the case of a structure in which the electrodes are arranged in a comb shape, it is enough to aggregate the solder particles in a direction perpendicular to the comb. In contrast, the above-mentioned surface array or peripheral structure needs to spread the solder particles over the entire surface on which the electrodes are arranged. surface evenly. Therefore, the amount of solder tends to become uneven in the conventional method, but the method of the present invention can more effectively exhibit the effects of the present invention.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.

Thermosetting ingredients (thermosetting compounds): Thermosetting compound 1: "D.E.N-431" manufactured by The Dow Chemical Company, epoxy resin Thermosetting compound 2: "jER152" manufactured by Mitsubishi Chemical Corporation, epoxy resin

Thermosetting ingredients (thermosetting agent): Thermosetting agent 1: "BF3-MEA" manufactured by Tokyo Chemical Industry Co., Ltd., boron trifluoride-monoethylamine complex Thermosetting agent 2: "2PZ-CN" manufactured by Shikoku Chemical Industry Co., Ltd., 1-cyanoethyl-2-phenylimidazole

Solder particles: Solder particle 1: Sn42Bi58 solder particle, melting point 138°C, particle size: 10 μm, average thickness of oxide film: 3 nm Solder particle 2: Sn42Bi58 solder particle, melting point 138°C, particle size: 5 μm, average thickness of oxide film: 5 nm Solder particle 3: Sn42Bi58 solder particle, melting point 138°C, particle size: 2 μm, average thickness of oxide film: 2 nm Solder particle 4: Sn42Bi58 solder particle, melting point 138°C, particle size: 10 μm, average thickness of oxide film: 6 nm Solder particle 5: Sn42Bi58 solder particle, melting point 138°C, particle size: 5 μm, average thickness of oxide film: 12 nm Solder particle 6: Sn42Bi58 solder particle, melting point 138°C, particle size: 2 μm, average thickness of oxide film: 4 nm

Flux: Flux 1: "Benzylamine glutarate", melting point 108°C

The production method of flux 1: 24 g of water as a reaction solvent and 13.212 g of glutaric acid (manufactured by Wako Pure Chemical Industries, Ltd.) were added to a glass bottle, and dissolved at room temperature until uniform. Thereafter, 10.715 g of benzylamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added and stirred for about 5 minutes to obtain a liquid mixture. Put the obtained mixture into a refrigerator at 5-10°C overnight. The precipitated crystals were collected by filtration, washed with water, and vacuum-dried to obtain flux 1 .

(Examples 1-6 and Comparative Examples 1-6) (1) Production of conductive materials (anisotropic conductive paste) The components shown in the following Tables 1 and 2 were blended in the amounts shown in the following Tables 1 and 2 to obtain a conductive material (anisotropic conductive paste).

(2) Fabrication of connection structure (L/S=100 μm/100 μm) Using the newly produced conductive material (anisotropic conductive paste), the connection structure was produced as follows.

Prepare a glass epoxy resin substrate (FR-4 substrate) with an L/S of 100 μm/100 μm and a copper electrode pattern with an electrode length of 3 mm on the upper surface (the thickness of the copper electrode is 12 μm) (the first connection object member) . Also, a flexible printed circuit board (second connection object member) having an L/S of 100 μm/100 μm and a copper electrode pattern (thickness of the copper electrode: 12 μm) having an electrode length of 3 mm on the lower surface was prepared.

The overlapping area of the above-mentioned glass epoxy substrate and the above-mentioned flexible printed substrate is set to 1.5 cm×3 mm, and the number of connected electrodes is set to 75 pairs.

On the upper surface of the above-mentioned glass epoxy resin substrate, the conductive material (anisotropic conductive paste) just produced was applied by screen printing using a metal mask on the electrode of the glass epoxy resin substrate so as to have a thickness of 100 μm, A conductive material (anisotropic conductive paste) layer is formed. Next, the above-mentioned flexible printed circuit board was laminated on the upper surface of the conductive material (anisotropic conductive paste) layer so that the electrodes faced each other. At this time, pressurization was not performed. The above-mentioned weight of the flexible printed circuit board is applied to the conductive material (anisotropic conductive paste) layer. From this state, heating was performed so that the temperature of the conductive material (anisotropic conductive paste) layer became the melting point of the solder 5 seconds after the start of the temperature rise. Furthermore, it heated so that the temperature of the conductive material (anisotropic conductive paste) layer might become 160 degreeC after 15 seconds from the start of temperature rise, hardened the conductive material (anisotropic conductive paste) layer, and obtained the connection structure. During heating, no pressurization was performed.

(evaluate) (1) The particle size of the solder particles and the average thickness of the oxide film The particle size of the solder particles was measured using a laser diffraction particle size distribution analyzer ("LA-920" manufactured by Horiba, Ltd.).

Also, the solder particles were heated at 120° C. for 10 hours in an air atmosphere. Use a transmission electron microscope to observe the cross-section of the solder particle before heating or the solder particle after heating, and calculate the average thickness of the oxide film before heating (average Thickness A) and the average thickness of the oxide film after heating (average thickness B).

Based on the measurement results of the particle size of the solder particles and the average thickness (average thickness A) of the oxide film of the solder particle before heating, calculate the average thickness (average thickness A) of the oxide film of the solder particle before heating relative to the particle size of the solder particle Diameter ratio (average thickness A/particle diameter of solder particles). Also, based on the measurement results of the average thickness (average thickness A and average thickness B) of the oxide film of the solder particle before and after heating, the average thickness (average thickness A) of the oxide film of the solder particle before heating was calculated relative to the solder after heating. The ratio of the average thickness (average thickness B) of the oxide film of the particles (average thickness A/average thickness B).

(2) Content of oxide film in 100% by volume of solder particles The content of the oxide film in 100% by volume of the solder particle was calculated from the weight of the solder particle before and after removal of the oxide film.

(3) Absolute value of heat release of solder particles above 200°C The heat generation of solder particles at 200°C or higher was measured using a differential scanning calorimetry (DSC) device ("EXSTAR DSC7020" manufactured by SII Corporation).

(4) Viscosity of conductive material at 25°C (η25(5 rpm)) The viscosity (η25 (5 rpm)) of the conductive material (anisotropic conductive paste) obtained at 25°C was measured using an E-type viscometer ("TVE22L" manufactured by Toki Sangyo Co., Ltd.) at 25°C and 5 The conditions of rpm are measured.

(5) Thixotropic index The viscosity (η25 (0.5 rpm)) of the obtained conductive material (anisotropic conductive paste) was measured using an E-type viscometer ("TVE22L" manufactured by Toki Sangyo Co., Ltd.) at 25°C and 0.5 rpm. The viscosity (η25 (5 rpm)) of the obtained conductive material (anisotropic conductive paste) was measured using an E-type viscometer ("TVE22L" manufactured by Toki Sangyo Co., Ltd.) at 25°C and 5 rpm.

According to the measurement results, calculate the viscosity of the conductive material (anisotropic conductive paste) measured using the E-type viscometer at 25°C and 0.5 rpm and divide it by the viscosity measured using the E-type viscometer at 25°C and 5 rpm Thixotropic index (η25(0.5 rpm)/η25(5 rpm)) obtained from the viscosity of the obtained conductive material (anisotropic conductive paste).

(6) The placement accuracy of the solder on the electrode (solder agglutination) In the obtained connection structure, when only the parts of the first electrode and the second electrode facing each other are observed in the stacking direction of the first electrode, the connection part, and the second electrode, the first electrode and the second electrode The ratio X of the area where the solder portion is arranged in the connecting portion out of 100% of the area of the mutually facing portion is evaluated. The placement accuracy of the solder on the electrodes (solder agglutination) was judged according to the following criteria.

[Criteria for judging the placement accuracy of the solder on the electrode (solder agglomeration)] ○○: Ratio X is 70% or more ○: Ratio X is 60% or more and less than 70% △: Ratio X is 50% or more and less than 60% ×: Ratio X is less than 50%

(7) Conduction reliability between upper and lower electrodes In the obtained connection structures (n=15 pieces), the connection resistance for each connection site between the upper and lower electrodes was measured by the four-terminal method. Calculate the average value of the connection resistance. Furthermore, according to the relationship of voltage=current×resistance, the connection resistance can be obtained by measuring the voltage when a fixed current flows. Conduction reliability was judged according to the following criteria.

[Criteria for judging conduction reliability] ○○: The average connection resistance is 50 mΩ or less ○: The average connection resistance exceeds 50 mΩ and is 70 mΩ or less △: The average connection resistance exceeds 70 mΩ and is 100 mΩ or less ×: The average value of connection resistance exceeds 100 mΩ, or poor connection occurs

(8) Insulation reliability between laterally adjacent electrodes After leaving the obtained connection structures (n=15 pieces) in an environment at 85° C. and a humidity of 85% for 100 hours, 5 V was applied between laterally adjacent electrodes, and resistance values were measured at 25 locations. Insulation reliability was judged by the following criteria.

[Criteria for judging insulation reliability] ○○: The average value of the connection resistance is 10 ⁷ Ω or more ○: The average value of the connection resistance is 10 ⁶ Ω or more and less than 10 ⁷ Ω △: The average value of the connection resistance is 10 ⁵ Ω More than but less than 10 ⁶ Ω ×: The average value of connection resistance is less than 10 ⁵ Ω

The results are shown in Tables 1 and 2 below.

[Table 1]

[Table 2]

The same tendency is also seen in the case of using flexible printed circuit boards, resin films, flexible flat cables, and rigid-flex substrates.

1‧‧‧connection structure 1X‧‧‧connection structure 2‧‧‧The first connection object component 2a‧‧‧1st electrode 3‧‧‧The second connection target member 3a‧‧‧Second electrode 4‧‧‧connection part 4A‧‧‧Solder Department 4B‧‧‧hardening department 4X‧‧‧Connection 4XA‧‧‧Solder Department 4XB‧‧‧hardened parts department 11‧‧‧Conductive materials 11A‧‧‧Solder particles 11B‧‧‧thermosetting components 21‧‧‧Solder particles 22‧‧‧Solder particle body 23‧‧‧Oxide film

Fig. 1 is a cross-sectional view schematically showing a connection structure obtained by using a conductive material according to an embodiment of the present invention. 2( a ) to ( 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. 3 is a cross-sectional view showing a modified example of the connection structure. Fig. 4 is a cross-sectional view showing an example of solder particles that can be used for conductive materials. Fig. 5 is a diagram for explaining the agglomeration of solder particles.

1‧‧‧connection structure

2‧‧‧The first connection object component

2a‧‧‧1st electrode

3‧‧‧The second connection target member

3a‧‧‧Second electrode

4‧‧‧connection part

4A‧‧‧Solder Department

4B‧‧‧hardening department

Claims (15)

A solder particle having a solder particle body and an oxide film disposed on the outer surface of the solder particle body, and The particle size of the above-mentioned solder particles is not less than 1 μm and not more than 15 μm, When the solder particles were heated at 120° C. for 10 hours in an air environment, the ratio of the average thickness of the oxide film before heating to the average thickness of the oxide film after heating was 2/3 or less. As for the solder particles in claim 1, the absolute value of the heat release at 200°C or higher is 100 mJ/mg or higher. a conductive material comprising a thermosetting component, and a plurality of solder particles, and The above-mentioned solder particle has a solder particle body and an oxide film disposed on the outer surface of the solder particle body, The particle size of the above-mentioned solder particles is not less than 1 μm and not more than 15 μm, When the solder particles were heated at 120° C. for 10 hours in an air environment, the ratio of the average thickness of the oxide film before heating to the average thickness of the oxide film after heating was 2/3 or less. The conductive material according to claim 3 has a viscosity at 25°C of not less than 10 Pa·s and not more than 600 Pa·s. Such as the conductive material of claim 3 or 4, wherein the viscosity measured by using an E-type viscometer at 25°C and 0.5 rpm is divided by the viscosity measured by using an E-type viscometer at 25°C and 5 rpm. The obtained thixotropic index is not less than 1.1 and not more than 5. The conductive material according to claim 3 or 4, wherein the absolute value of the exothermic heat of the above-mentioned solder particles at 200°C or higher is 100 mJ/mg or higher. As the conductive material of claim 3 or 4, it is a conductive paste. A storage method for solder particles, which is the storage method for solder particles as claimed in claim 1 or 2, and the method is to put the above solder particles into a storage container and store them under an inert gas environment, or put the above solder particles into Put it into a storage container and store it in a vacuum under the condition of 1×10 ² Pa or less. A storage method for conductive materials, which is the storage method for conductive materials according to any one of claims 3 to 7, and In this method, the conductive material is placed in a storage container and stored at a temperature of -40°C to 10°C, or the conductive material is placed in a storage container and stored under an inert gas atmosphere. A method for producing a conductive material, which includes a mixing step of mixing a thermosetting component and a plurality of solder particles to obtain a conductive material, and The manufacturing method of the conductive material obtains the following conductive material: the above-mentioned solder particle has a solder particle body and an oxide film arranged on the outer surface of the above-mentioned solder particle body, the particle size of the above-mentioned solder particle is not less than 1 μm and not more than 15 μm. When the solder particles were heated at 120° C. for 10 hours in an air environment, the ratio of the average thickness of the oxide film before heating to the average thickness of the oxide film after heating was 2/3 or less. The method of manufacturing a conductive material according to claim 10, further comprising a storage step of storing the above-mentioned solder particles, and the above-mentioned storage step is a step of putting the above-mentioned solder particles into a storage container and storing them under an inert gas environment, or storing the above-mentioned solder particles in an inert gas environment. The step of putting the above-mentioned solder particles into a storage container and storing them in a vacuum under the condition of 1×10 ² Pa or less. The above-mentioned solder particles are solder particles stored in the above-mentioned storage step. A connection structure having: a first connection target member having a first electrode on its surface, a second connection object member having a second electrode on its surface, and connecting the connecting portion of the first connection object member and the second connection object member, and The material of the above-mentioned connection part includes the solder particles as claimed in item 1 or 2, The first electrode and the second electrode are electrically connected by the solder part in the connection part. A connection structure having: a first connection target member having a first electrode on its surface, a second connection target member having a second electrode on its surface; and connecting the connecting portion of the first connection object member and the second connection object member, and The material of the above-mentioned connecting portion is the conductive material according to any one of claims 3 to 7, The first electrode and the second electrode are electrically connected by the solder part in the connection part. A method of manufacturing a connecting structure, comprising the steps of: Using a conductive material containing solder particles according to claim 1 or 2, disposing the above-mentioned conductive material on the surface of the first connection object member having the first electrode on the surface; disposing a second connection object member having a second electrode on its surface on the surface of the conductive material opposite to the side of the first connection object member in such a manner that the first electrode and the second electrode face each other; and By heating the conductive material above the melting point of the solder particles, the connection portion connecting the first connection object member and the second connection object member is formed from the above conductive material, and the solder portion in the connection portion connects The first electrode is electrically connected to the second electrode. A method for manufacturing a connection structure, which includes the following steps: using the conductive material according to any one of claims 3 to 7, and disposing the above-mentioned conductive material on the surface of the first connection object member having the first electrode on the surface; disposing a second connection object member having a second electrode on its surface on the surface of the conductive material opposite to the side of the first connection object member in such a manner that the first electrode and the second electrode face each other; and By heating the conductive material above the melting point of the solder particles, the connection portion connecting the first connection object member and the second connection object member is formed from the above conductive material, and the solder portion in the connection portion connects The first electrode is electrically connected to the second electrode.

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