WO2022065418A1 - Sintering composition, sintered body, and bonded structure - Google Patents

Abstract

Provided is a sintering composition that can enhance bonding reliability when used as a bonding material.　A sintering composition according to the present invention contains a metal component capable of transient liquid phase sintering and a plurality of metal-coated particles, wherein the metal component contains at least two types of metal particles having different main metals, and the metal-coated particles each include a base particle different from a metal particle and a metal part disposed on the surface of the base particle.

Description

Sintering compositions, sintered bodies and bonded structures

The present invention relates to a sintering composition used by sintering. The present invention relates to a sintered body and a bonded structure using the above-mentioned sintering composition.

In recent years, power semiconductor devices using wide bandgap semiconductors such as silicon carbide and gallium nitride have been used. A power semiconductor device is manufactured, for example, by joining a substrate and a semiconductor element with a bonding material. The bonding material needs to be a material having excellent conductivity, heat dissipation, and heat resistance in order to stably drive the power semiconductor device.

Lead-containing solder is widely used as a bonding material, but from the viewpoint of reducing the environmental load, switching to lead-free solder such as Sn-Ag-Cu alloy is being promoted. However, conventional lead-free solders such as Sn-Ag-Cu alloys have a lower melting point than lead-containing solders, and when exposed to a high temperature environment after bonding, they remelt and the bonding reliability decreases. There are challenges.

To solve such a problem, Patent Document 1 below discloses a composition capable of obtaining a sintered body capable of increasing the bonding strength even in a high temperature environment. Specifically, Patent Document 1 below contains a metal component capable of transitional liquid phase sintering, and the metal component includes metal particles A having a melting point higher than 300 ° C. and a melting point of 300 ° C. or lower. A composition comprising metal particles B is disclosed. In this composition, the void volume X (cm ³ ) of the metal particles A, the density Y (g / cm ³ ) of the metal particles B, and the amount Z (g) of the metal particles B satisfy a specific relationship. ..

WO2020 / 017065A1

When the composition described in Patent Document 1 is used as a bonding material, the bonding strength between the bonded portion formed by the sintered body of the composition and the member to be bonded can be increased to some extent even in a high temperature environment. can. However, even with the composition described in Patent Document 1, the bonding strength may decrease and the bonding reliability may decrease.

Further, in the conventional joining material as described in Patent Document 1, cracks may occur in the joining portion due to the difference in the coefficient of thermal expansion of the joining target member, or the joining target member and the joining portion may be connected to each other. Interface peeling may occur at the interface of. When cracks or interfacial delamination occur, the bonding strength decreases, and as a result, the bonding reliability decreases.

An object of the present invention is to provide a sintering composition capable of enhancing joining reliability when used as a joining material. Another object of the present invention is to provide a sintered body and a bonded structure using the above-mentioned sintering composition.

According to a broad aspect of the present invention, a metal component capable of transitional liquid phase sintering and a plurality of metal-coated particles are included, and the metal component contains two or more kinds of metal particles having different main metals from each other. A composition for sintering is provided in which the metal-coated particles include a base material particles different from the metal particles and a metal portion arranged on the surface of the base material particles.

In a specific aspect of the sintering composition according to the present invention, the metal component includes metal particles containing copper as a main metal and metal particles containing tin as a main metal.

In a specific aspect of the sintering composition according to the present invention, the base particles of the metal-coated particles are resin particles.

In certain aspects of the sintering composition according to the present invention, the metal portion of the metal-coated particles may be copper, tin, gold, silver, nickel, indium, gallium, zinc, antimony, palladium, ruthenium, bismuth, etc. Includes platinum or alloys thereof.

In a specific aspect of the sintering composition according to the present invention, the content of the metal-coated particles is 0.005% by weight or more and 30% by weight or less.

In a specific aspect of the sintering composition according to the present invention, the compressive elastic modulus when the metal-coated particles are compressed by 20% at 25 ° C. is 100 N / mm ² or more and 20000 N / mm ² or less.

In a specific aspect of the sintering composition according to the present invention, the particle size of the metal-coated particles is 1 μm or more and 100 μm or less.

In a specific aspect of the sintering composition according to the present invention, the metal portion of the metal-coated particles has protrusions on the outer surface.

In certain aspects of the sintering composition according to the present invention, the sintering composition contains a flux component.

In a specific aspect of the sintering composition according to the present invention, the sintering composition contains a binder resin, and the binder resin contains a thermoplastic component or a thermosetting component.

In a particular aspect of the sintering composition according to the present invention, the sintering composition is a bonding material.

According to a broad aspect of the present invention, there is provided a sintered body obtained by sintering the above-mentioned sintering composition.

According to a broad aspect of the present invention, a first joining target member, a second joining target member, and a joining portion joining the first joining target member and the second joining target member are formed. Provided is a joint structure in which the joint portion is formed of the above-mentioned sintered body.

In a specific aspect of the joining structure according to the present invention, the first joining target member is a support member, and the second joining target member is an element.

The sintering composition according to the present invention contains a metal component capable of transitional liquid phase sintering and a plurality of metal-coated particles. In the sintering composition according to the present invention, the metal component contains two or more kinds of metal particles having different main metals from each other, and the metal-coated particles are a base particle different from the metal particles and the base particle. It comprises a metal part arranged on the surface of the. Since the sintering composition according to the present invention has the above-mentioned structure, it is possible to improve the joining reliability when used as a joining material.

FIG. 1 is a cross-sectional view schematically showing a first example of metal-coated particles that can be used in the sintering composition according to the present invention. FIG. 2 is a cross-sectional view schematically showing a second example of metal-coated particles that can be used in the sintering composition according to the present invention. FIG. 3 is a cross-sectional view schematically showing a third example of metal-coated particles that can be used in the sintering composition according to the present invention.

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

The sintering composition according to the present invention contains a metal component capable of transitional liquid phase sintering and a plurality of metal-coated particles. In the sintering composition according to the present invention, the metal component contains two or more kinds of metal particles having different main metals from each other, and the metal-coated particles are a base particle different from the metal particles and the base particle. It comprises a metal part arranged on the surface of the. The metal-coated particles are composite particles comprising the base material particles and the metal portion.

Since the sintering composition according to the present invention has the above-mentioned structure, it is possible to improve the joining reliability when used as a joining material.

In the present invention, the above sintering composition (bonding material) is placed between the members to be joined, and the placed sintering composition is heated to sinter the metal particles and the metal-coated particles for joining. The target members can be joined to each other. The members to be joined are joined via a joining portion formed by the sintered body of the sintering composition. In the sintering composition according to the present invention, the conductivity, heat dissipation and heat resistance of the bonded portion can be enhanced, and further, metal-coated particles having specific base material particles are used. Therefore, the bonded portion is used. The elastic modulus of the portion can be lowered. Therefore, in the sintering composition according to the present invention, even when members to be bonded having different coefficients of thermal expansion are bonded to each other, cracks in the joint and the target to be bonded due to warpage of the members to be bonded and generation of thermal stress are generated. The occurrence of interface peeling at the interface between the member and the joint can be effectively suppressed, and the adhesive force between the joint and the member to be joined can be enhanced.

Further, in the sintering composition according to the present invention, when the metal-coated particles exert a function as a spacer, the members to be bonded can be bonded to each other substantially in parallel. Therefore, the stress concentration on the end of the joint can be relaxed.

In the sintering composition according to the present invention, for example, for sintering as a bonding material such as a die attach paste or a material for adhering a heat radiating member, or as a bonding material for which reflow treatment is performed or large area bonding is required. Even if the composition is used, the bonding reliability can be improved over a long period of time.

(Metal components capable of transitional liquid phase sintering)
The sintering composition according to the present invention contains a metal component capable of transitional liquid phase sintering. The metal component includes two or more kinds of metal particles having different main metals from each other. The metal component may contain two types of metal particles having different main metals from each other, may contain three types, or may contain three or more types.

The combinations of the metal components include a combination of metal particles containing copper and metal particles containing tin, a combination of metal particles containing silver and metal particles containing indium, and metal particles containing tin and metal particles containing silver. The combination of metal particles containing tin and metal particles containing cobalt, the combination of metal particles containing tin and metal particles containing nickel, and the combination of metal particles containing gold and metal particles containing indium, etc. Can be mentioned.

In the present invention, the main metal means the metal having the highest content among the metals contained in the metal particles. In the present invention, the main metal is preferably a metal having a content of 30% by weight or more in 100% by weight of the metal particles, and a metal having a content of 50% by weight or more in 100% by weight of the metal particles. It is more preferable that the metal has a content of more than 50% by weight in 100% by weight of the metal particles.

Further, among the metals contained in the metal particles, when the content of the metal having the highest content is two or more, there are two or more types of metals having the same content in 100% by weight of the metal particles, and the main metal is 2. There will be more than seeds. When two or more metals having the highest content among the metals contained in the metal particles, at least one of the two or more metals having the highest content is the main metal in the other metal particles. It suffices if they are different from each other. For example, metal particles containing a metal (a1) and a metal (a2) as two or more kinds of metal particles having different main metals from each other, and the content of the metal (a1) and the content of the metal (a2) are the same. There may be metal particles (B) containing (A), a metal (b1) and a metal (b2), and the content of the metal (b1) is higher than the content of the metal (b2). In this case, at least one of the metal (a1) and the metal (a2) may be different from the metal (b1). It is preferable that both the metal (a1) and the metal (a2) are different from the metal (b1). In two or more kinds of metal particles in which the main metals are different from each other, it is sufficient that at least one kind of the main metal is different from each other, and it is preferable that all of the main metals are different from each other. In two or more kinds of metal particles having different main metals from each other, at least one kind of the main metal of one metal particle may be different from the main metal of the other metal particle. In two or more kinds of metal particles in which the main metals are different from each other, it is preferable that all the main metals of one metal particle are different from the main metal of the other metal particle.

The metal component capable of transitional liquid phase sintering preferably contains metal particles containing copper and metal particles containing tin, and the metal particles containing copper as the main metal and the metal containing tin as the main metal. It is more preferable to include particles. In this case, the sintering time can be shortened and the manufacturing cost can be lowered.

The metal particles containing copper as a main metal may be copper particles or alloy particles containing copper. From the viewpoint of more effectively exerting the effect of the present invention, the copper content is preferably 30% by weight or more, more preferably 50% by weight or more, in 100% by weight of the metal particles containing copper as the main metal. It is even more preferably more than 50% by weight, still more preferably 65% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The copper content may be 100% by weight in 100% by weight of the metal particles containing copper as the main metal. The tin content in 100% by weight of the metal particles containing copper as a main metal is preferably less than 50% by weight, more preferably 30% by weight or less, still more preferably less than 30% by weight, still more preferably 20% by weight. Below, it is particularly preferably 10% by weight or less. The metal particles containing copper as a main metal may or may not contain tin.

From the viewpoint of further shortening the sintering time and further effectively exerting the effect of the present invention, the metal particles containing copper as the main metal are preferably copper particles.

The metal particles containing tin as a main metal may be tin particles or alloy particles containing tin. Examples of the metal contained in the metal particles containing tin as the main metal include Sn—Ag—Cu alloy, Sn—Bi alloy, Sn—In alloy, Sn—Zn alloy, Sn—Cu alloy, and Sn—Cu—Ni alloy. Sn-Ag alloy, Sn-Sb alloy, Sn-Bi-Sb-Ni alloy, Sn-Bi-Cu-P alloy, Sn-Ag-Cu-In alloy, Sn-Cu-Ag-P-Ga alloy, Sn- Cu-Ni-P-Ga alloy, Sn-Cu-Ag-Ni-Ge alloy, Sn-Bi-Cu-In alloy, Sn-Ag-Bi-Cu alloy, Sn-Ag-Cu-Bi-Ni alloy, Sn -Bi-Ag-Cu-In alloy, Sn-In-Ag-Bi alloy, Sn-Zn-Bi alloy and the like can be mentioned.

The tin content in 100% by weight of the metal particles containing tin as a main metal is preferably 5% by weight or more, more preferably 10% by weight or more, still more preferably 30% by weight or more, and particularly preferably 40% by weight or more. Is. The tin content in 100% by weight of the metal particles containing tin as a main metal may be 50% by weight or more, may exceed 50% by weight, or may be 65% by weight or more. It may be 80% by weight or more, 90% by weight or more, or 100% by weight. From the viewpoint of more effectively exerting the effect of the present invention, the tin content is preferably 50% by weight or more, more preferably more than 50% by weight in 100% by weight of the metal particles containing tin as the main metal. It is more preferably 65% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The copper content in 100% by weight of the metal particles containing tin as a main metal is preferably less than 50% by weight, more preferably 30% by weight or less, still more preferably less than 30% by weight, still more preferably 20% by weight. Below, it is particularly preferably 10% by weight or less. The metal particles containing tin as a main metal may or may not contain copper.

From the viewpoint of further shortening the sintering time and further effectively exerting the effect of the present invention, the metal particles containing tin as the main metal are metal particles containing a Sn—Ag—Cu alloy or metal particles. Metal particles containing a Sn—Bi alloy are preferable, and metal particles containing a Sn—Ag—Cu alloy are more preferable.

The particle diameters of the two or more metal particles having different main metals from each other are preferably 0.5 μm or more, more preferably 1 μm or more, preferably 60 μm or less, and more preferably 30 μm or less, respectively. When the particle diameters of two or more kinds of metal particles having different main metals from each other are equal to or more than the above lower limit and not more than the above upper limit, the sintering composition can be sintered satisfactorily, and the effect of the present invention can be further enhanced. It can be demonstrated more effectively.

The particle size of the metal particles containing copper as the main metal is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 60 μm or less, and more preferably 30 μm or less. When the particle size of the metal particles containing copper as the main metal is not less than the above lower limit and not more than the above upper limit, the sintering composition can be sintered satisfactorily, and the effect of the present invention is further effective. Can be demonstrated.

The metal particles containing copper as a main metal preferably include first particles having a particle diameter of 1 μm or more and 60 μm or less, and second particles having a particle diameter of 1 μm or more and 15 μm or less. In this case, the sintering composition can be sintered satisfactorily, and the effect of the present invention can be more effectively exhibited.

The particle size of the first particle is preferably 3 μm or more, preferably 30 μm or less.

The particle size of the second particle is preferably 3 μm or more, preferably 10 μm or less.

The particle size of the metal particles containing tin as the main metal is preferably 1 nm or more, more preferably 3 nm or more, preferably 15 μm or less, and more preferably 10 μm or less. When the particle size of the metal particles containing tin as the main metal is not less than the above lower limit and not more than the above upper limit, the sintering composition can be sintered satisfactorily, and the effect of the present invention is further effective. Can be demonstrated.

The particle size of each of the above metal particles is preferably an average particle size, and more preferably a number average particle size. The particle size of the metal particles can be obtained by observing 50 arbitrary metal particles with an electron microscope or an optical microscope, calculating the average value of the particle size of each metal particle, or using a particle size distribution measuring device. .. In observation with an electron microscope or an optical microscope, the particle size of each metal particle is determined as the particle size in the equivalent circle diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 metal particles in the equivalent circle diameter is substantially equal to the average particle diameter in the equivalent diameter of the sphere. In the particle size distribution measuring device, the particle size of each metal particle is obtained as the particle size in the equivalent sphere diameter. The average particle size of the metal particles is preferably calculated using a particle size distribution measuring device.

The content of the metal component capable of transitional liquid phase sintering in 100% by weight of the sintering composition is preferably 60% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more. It is preferably less than 100% by weight, more preferably 99% by weight or less, still more preferably 98% by weight or less. When the content of the metal component capable of transitional liquid phase sintering is equal to or higher than the lower limit and lower than the upper limit or lower than the upper limit, the effect of the present invention can be more effectively exhibited.

The content of the metal particles containing copper as the main metal in 100% by weight of the sintering composition is preferably 20% by weight or more, more preferably 30% by weight or more, still more preferably 40% by weight or more, preferably 40% by weight or more. It is less than 100% by weight, more preferably 95% by weight or less, still more preferably 90% by weight or less. When the content of the metal particles containing copper as the main metal is equal to or higher than the lower limit and lower than the upper limit or lower than the upper limit, the effect of the present invention can be more effectively exhibited.

When the metal particles containing copper as the main metal include the first particles and the second particles, it is preferable to satisfy the following content relationship. The content of the first particles in 100% by weight of the sintering composition is preferably 20% by weight or more, more preferably 30% by weight or more, still more preferably 40% by weight or more, and preferably less than 100% by weight. , More preferably 95% by weight or less, still more preferably 90% by weight or less. When the content of the first particles is equal to or higher than the lower limit and lower than the upper limit or lower than the upper limit, the effect of the present invention can be more effectively exhibited.

When the metal particles containing copper as the main metal include the first particles and the second particles, it is preferable to satisfy the following content relationship. The content of the second particles in 100% by weight of the sintering composition is preferably 10% by weight or more, more preferably 15% by weight or more, still more preferably 20% by weight or more, and preferably 80% by weight or less. , More preferably 70% by weight or less, still more preferably 60% by weight or less. When the content of the second particle is not less than the above lower limit and not more than the above upper limit, the effect of the present invention can be exhibited even more effectively.

The content of the metal particles containing tin as the main metal in 100% by weight of the sintering composition is preferably 10% by weight or more, more preferably 15% by weight or more, still more preferably 20% by weight or more, preferably 20% by weight or more. It is 80% by weight or less, more preferably 70% by weight or less, still more preferably 60% by weight or less. When the content of the metal particles containing tin as the main metal is not less than the above lower limit and not more than the above upper limit, the effect of the present invention can be exhibited even more effectively.

(Metal-coated particles)
The sintering composition according to the present invention contains a plurality of metal-coated particles. The metal-coated particles include a base particle different from the metal particles and a metal portion arranged on the surface of the base particles. The metal component capable of transitional liquid phase sintering is different from particles having a base particle different from the metal particle and a metal portion arranged on the surface of the base particle.

Hereinafter, specific details of the metal-coated particles that can be used in the sintering composition according to the present invention will be described with reference to the drawings. In addition, in FIG. 1 and the figure described later, different parts can be replaced with each other.

FIG. 1 is a cross-sectional view schematically showing a first example of metal-coated particles that can be used in the sintering composition according to the present invention.

The metal-coated particles 1 shown in FIG. 1 have a base particle 2 and a metal portion 3. The base particle 2 is different from the metal particle. In the first example, the base particle 2 is a resin particle. The metal portion 3 is arranged on the surface of the base particle 2. In the first example, the metal portion 3 is in contact with the surface of the base particle 2. The metal-coated particles 1 are coated particles in which the surface of the base particle 2 is coated with the metal portion 3.

In the metal-coated particles 1, the metal portion 3 is a single metal layer.

The metal-coated particles 1 do not have a core substance, unlike the metal-coated particles 1B described later. The metal-coated particles 1 have no protrusions on the surface. The metal-coated particles 1 are spherical. The metal portion 3 has no protrusion on the outer surface.

FIG. 2 is a cross-sectional view schematically showing a second example of metal-coated particles that can be used in the sintering composition according to the present invention.

The metal-coated particles 1A shown in FIG. 2 have a base particle 2 and a metal portion 3A. The base particle 2 is different from the metal particle. The metal-coated particles 1A have a first metal portion 31A and a second metal portion 32A as the metal portion 3A. The metal portion 3A has a two-layer structure. As a whole, the metal portion 3A has a second metal portion 32A on the base particle 2 side and a first metal portion 31A on the side opposite to the base particle 2 side. The first metal portion 31A and the second metal portion 32A are formed as separate metal portions.

The second metal portion 32A is arranged on the surface of the base particle 2. A second metal portion 32A is arranged between the base particle 2 and the first metal portion 31A. The second metal portion 32A is in contact with the base particle 2. The first metal portion 31A is in contact with the second metal portion 32A. Therefore, the second metal portion 32A is arranged on the surface of the base particle 2, and the first metal portion 31A is arranged on the surface of the second metal portion 32A.

The metal-coated particles 1A do not have a core substance, unlike the metal-coated particles 1B described later. The metal-coated particles 1A have no protrusions on the surface. The metal-coated particles 1A are spherical. The metal portion 3A has no protrusion on the outer surface.

FIG. 3 is a cross-sectional view schematically showing a third example of metal-coated particles that can be used in the sintering composition according to the present invention.

The metal-coated particles 1B shown in FIG. 3 have a base particle 2, a metal portion 3B, and a plurality of core substances 4. The base particle 2 is different from the metal particle. The metal-coated particles 1B have a first metal portion 31B and a second metal portion 32B as the metal portion 3B. The metal portion 3B has a two-layer structure. As a whole, the metal portion 3B has a second metal portion 32B on the base particle 2 side and a first metal portion 31B on the side opposite to the base particle 2 side. The first metal portion 31B and the second metal portion 32B are formed as separate metal portions.

The second metal portion 32B is arranged on the surface of the base particle 2. A second metal portion 32B is arranged between the base particle 2 and the first metal portion 31B. The second metal portion 32B is in contact with the base particle 2. The first metal portion 31B is in contact with the second metal portion 32B. Therefore, the second metal portion 32B is arranged on the surface of the base particle 2, and the first metal portion 31B is arranged on the surface of the second metal portion 32B.

The metal-coated particles 1B have a plurality of protrusions 1Ba on the outer surface. The metal portion 3B has a plurality of protrusions 3Ba on the outer surface. The first metal portion 31B has a plurality of protrusions 31Ba on the outer surface. The second metal portion 32B has a plurality of protrusions 32Ba on the outer surface. A plurality of core substances 4 are arranged on the surface of the base particle 2. The plurality of core substances 4 are embedded in the metal portion 3B. The core material 4 is arranged inside the protrusions 1Ba, 3Ba, 31Ba, 32Ba. The metal portion 3B covers a plurality of core substances 4. The second metal portion 32B covers a plurality of core substances 4. The outer surface of the metal portion 3B is raised by the plurality of core substances 4, and protrusions 1Ba, 3Ba, 31Ba, 32Ba are formed.

In the metal-coated particles, the metal portion may cover the entire surface of the base particles, or may cover a part of the surface of the base particles. In the metal-coated particles, the metal portion may be a single-layer metal layer or a multi-layered metal layer composed of two or more layers. The metal-coated particles may or may not have protrusions on the surface. The metal-coated particles may or may not be spherical.

The details of the metal-coated particles will be described below.

<Base particles>
The metal-coated particles include base particles. The base particle is a base particle different from the metal particle.

The material of the base particle may be an organic material or an inorganic material. Examples of the base particles formed only of the organic material include resin particles and the like. Examples of the base particles formed only of the above-mentioned inorganic material include inorganic particles excluding metal particles. Examples of the base particle formed by both the organic material and the inorganic material include organic-inorganic hybrid particles and the like. The base material particles are preferably resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles, and more preferably resin particles. In particular, when the base particles are resin particles, the flexibility of the metal-coated particles can be increased, so that the thermal stress is effectively relaxed even when the members to be bonded having different coefficients of thermal expansion are bonded to each other. It is possible to improve the joining reliability for a longer period of time.

Examples of the organic material include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene and polybutadiene; acrylic resins such as polymethylmethacrylate and polymethylacrylate; polycarbonate, polyamide, phenolformaldehyde resin and melamine. Formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, Examples thereof include polyether ether ketone, polyether sulfone, silicone, bismaleimide, and divinylbenzene polymer. The divinylbenzene polymer may be a divinylbenzene copolymer. Examples of the divinylbenzene copolymer and the like include a divinylbenzene-styrene copolymer and a divinylbenzene- (meth) acrylic acid ester copolymer. Since the compression characteristics of the base particles can be easily controlled within a suitable range, the material of the base particles is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. Is preferable.

When the substrate particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group is crosslinked with a non-crosslinkable monomer. Examples include sex monomers.

Examples of the non-crosslinkable monomer include styrene monomers such as styrene, α-methylstyrene, and chlorstyrene; vinyl ether compounds such as methylvinyl ether, ethylvinyl ether, and propylvinyl ether; vinyl acetate, vinyl butyrate, and the like. Acid vinyl ester compounds such as vinyl laurate and vinyl stearate; halogen-containing monomers such as vinyl chloride and vinyl fluoride; as (meth) acrylic compounds, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth). ) Alkyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, etc. Meta) Acrylate compound; Oxygen atom-containing (meth) acrylate compound such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate; (meth) acrylonitrile, etc. Nitrile-containing monomer; Halogen-containing (meth) acrylate compound such as trifluoromethyl (meth) acrylate and pentafluoroethyl (meth) acrylate; olefins such as diisobutylene, isobutylene, linearene, ethylene and propylene as α-olefin compounds. Compound; Examples of the conjugated diene compound include isoprene and butadiene.

The crosslinkable monomer is a vinyl monomer such as divinylbenzene, 1,4-dibinyloxybutane, or divinylsulfone as a vinyl compound; and tetramethylolmethanetetra (meth) acrylate as a (meth) acrylic compound. , Polytetramethylene glycol diacrylate, Tetramethylol methanetri (meth) acrylate, Tetramethylol methanedi (meth) acrylate, Trimethylol propanetri (meth) acrylate, Dipentaerythritol hexa (meth) acrylate, Dipentaerythritol penta (meth) ) Acrylic, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, 1,4-butanediol di Polyfunctional (meth) acrylate compounds such as (meth) acrylate; as allyl compounds, triallyl (iso) cyanurate, triallyl trimellitate, diallylphthalate, diallylacrylamide, diallyl ether; as silane compounds, tetramethoxysilane and tetraethoxysilane. , Methyltrimethoxysilane, Methyltriethoxysilane, Ethyltrimethoxysilane, Ethyltriethoxysilane, Isopropyltrimethoxysilane, Isobutyltrimethoxysilane, Cyclohexyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, trimethoxysilylstyrene, γ- (meth) acryloxipropyltrimethoxysilane, 1,3-divinyltetramethyldi Silane alkoxide compounds such as siloxane, methylphenyldimethoxysilane, diphenyldimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsisilane, dimethoxyethylvinylsilane, diethoxymethylvinylsilane, diethoxyethylvinylsilane, ethylmethyldivinylsilane , Methylvinyldimethoxysilane, ethylvinyldimethoxysilane, methylvinyldiethoxysilane, ethylvinyldiethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylme Polymeric double-bonded silane alkoxides such as tyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane Cyclic siloxane such as decamethylcyclopentasiloxane; Modified (reactive) silicone oil such as single-ended silicone oil, double-ended silicone oil, side-chain silicone oil; (meth) acrylic acid, maleic acid, maleic anhydride, etc. Examples thereof include the carboxyl group-containing monomer of.

The base particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group. The above polymerization method is not particularly limited, and examples thereof include known methods such as radical polymerization, ionic polymerization, polycondensation (condensation polymerization, polycondensation), addition condensation, living polymerization, and living radical polymerization. Further, as another polymerization method, suspension polymerization in the presence of a radical polymerization initiator can be mentioned.

Examples of the inorganic material include silica, alumina, titanium oxide, barium titanate, zirconia, carbon black, silicon carbide, silicon nitride, boron nitride, silicate glass, borosilicate glass, lead glass, soda-lime glass and alumina silicate glass. Can be mentioned.

The base particle may be an organic-inorganic hybrid particle. The base particles may be core-shell particles. When the base particle is an organic-inorganic hybrid particle, examples of the inorganic substance which is the material of the base particle include silica, alumina, barium titanate, titanium oxide, zirconia, and carbon black. It is preferable that the inorganic substance is not a metal. The base particles formed of the silica are not particularly limited, but after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, firing is performed as necessary. Examples thereof include substrate particles obtained by carrying out the process. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell arranged on the surface of the core. It is preferable that the core is an organic core. It is preferable that the shell is an inorganic shell. The base particle is preferably an organic-inorganic hybrid particle having an organic core and an inorganic shell arranged on the surface of the organic core.

Examples of the material of the organic core include the above-mentioned organic material and the like.

Examples of the material of the inorganic shell include the above-mentioned inorganic substances as the material of the base particle. The material of the inorganic shell is preferably silica. The inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material by a sol-gel method on the surface of the core and then firing the shell-like material. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed of silane alkoxide.

The base material particles are preferably resin particles, and more preferably divinylbenzene polymer particles, acrylic resin particles, epoxy resin particles, bismaleimide resin particles, silicone particles or polyolefin resin particles. The material of the base material is more preferably a divinylbenzene polymer, an acrylic resin, an epoxy resin, a bismaleimide resin, a silicone or a polyolefin resin. In this case, the joining reliability can be improved for a longer period of time. The divinylbenzene polymer particles may be divinylbenzene copolymer particles. The divinylbenzene polymer may be a divinylbenzene copolymer.

The particle size of the base material particles can be selected in consideration of the particle size of the metal-coated particles. The particle size of the base particles is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 3 μm or more, preferably 100 μm or less, more preferably 50 μm or less, still more preferably 30 μm or less. When the particle size of the base material particles is equal to or greater than the above lower limit and equal to or less than the above upper limit, the generated metal-coated particles are further aggregated when the metal portion is formed on the surface of the base material particles to obtain the metal-coated particles. It becomes difficult, and even when stress is applied to the metal portion, the metal portion becomes more difficult to peel off from the surface of the base particle.

When the metal-coated particles are used as spacers, the particle size of the base particles is preferably 20 μm or more, more preferably 30 μm or more, still more preferably 40 μm or more, preferably 100 μm or less, and more preferably 80 μm or less. , More preferably 60 μm or less.

The particle size of the base particles is preferably an average particle size, and preferably a number average particle size. For the particle size of the base particle, 50 arbitrary base particles are observed with an electron microscope or an optical microscope, the average value of the particle size of each base particle is calculated, or a particle size distribution measuring device is used. Is required. In observation with an electron microscope or an optical microscope, the particle size of each base particle is determined as the particle size in the equivalent circle diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 substrate particles in the equivalent circle diameter is substantially equal to the average particle diameter in the equivalent sphere diameter. In the particle size distribution measuring device, the particle size of each base particle is determined as the particle size at the equivalent sphere diameter. The average particle size of the base particles is preferably calculated using a particle size distribution measuring device. When measuring the particle size of the base material particles in the metal-coated particles, for example, the measurement can be performed as follows.

Add to "Technobit 4000" manufactured by Kulzer so that the content of the metal-coated particles is 30% by weight, and disperse the mixture to prepare an embedded resin body for metal-coated particle inspection. A cross section of the metal-coated particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the metal-coated particles dispersed in the embedded resin body for inspection. Then, using a field emission scanning electron microscope (FE-SEM), 50 metal-coated particles are randomly selected, and the base particles of each metal-coated particle are observed. The particle size of the base particle in each metal-coated particle is measured, and they are arithmetically averaged to obtain the particle size of the base particle.

<Metal part>
The metal-coated particles include metal portions arranged on the surface of the base particles. The metal constituting the metal portion is not particularly limited.

The metals constituting the metal part include gold, silver, palladium, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, tarium, germanium, cadmium, and the like. Examples thereof include silicon, tungsten, molybdenum and alloys thereof. Examples of the metal constituting the metal portion include tin-doped indium oxide (ITO) and solder. As the metal constituting the metal portion, only one kind may be used, or two or more kinds may be used in combination.

From the viewpoint of exerting the effect of the present invention even more effectively, the metal portion is copper, tin, gold, silver, nickel, indium, gallium, zinc, antimony, palladium, ruthenium, bismuth, platinum, or any of these. It preferably contains an alloy, more preferably copper, tin, nickel, gold or palladium, and even more preferably copper, tin, or nickel.

The metal portion may be formed by one layer. The metal portion may be formed of a plurality of layers. That is, the metal portion may have a laminated structure of two or more layers. When the metal portion is formed of a plurality of layers, the metals constituting the outermost layer are copper, tin, gold, silver, nickel, indium, gallium, zinc, antimony, palladium, ruthenium, bismuth, platinum, and the like. Alternatively, it is preferably an alloy thereof, and more preferably copper, tin, nickel, gold or palladium. When the metal constituting the outermost layer is these preferable metals, the connection resistance between the electrodes is further lowered.

The method of forming the metal portion on the surface of the base particle is not particularly limited. Examples of the method for forming the metal portion include a method by electroless plating, a method by electroplating, a method by physical collision, a method by a mechanochemical reaction, a method by physical vapor deposition or physical adsorption, and a metal powder or a metal powder. Examples thereof include a method of coating the surface of the substrate particles with a paste containing the binder and the binder. The method for forming the metal portion is preferably electroless plating, electroplating, or a method by physical collision. Examples of the method by physical vapor deposition include vacuum deposition, ion plating, and ion sputtering. Further, as the method by the above physical collision, a sheeter composer (manufactured by Tokuju Kosakusho Co., Ltd.) or the like is used.

The thickness of the metal portion is preferably 10 nm or more, more preferably 100 nm or more, preferably 10 μm or less, more preferably 1 μm or less, still more preferably 0.5 μm or less. The thickness of the metal portion is the thickness of the entire metal portion when the metal portion has multiple layers. When the thickness of the metal portion is not less than the above lower limit and not more than the above upper limit, sufficient conductivity can be obtained and the metal-coated particles can be prevented from becoming too hard.

When the metal portion is formed of a plurality of layers, the thickness of the metal portion of the outermost layer is preferably 1 nm or more, more preferably 10 nm or more, preferably 5 μm or less, and more preferably 1 μm or less. When the thickness of the metal portion of the outermost layer is equal to or higher than the lower limit and lower than the upper limit, the coating by the metal portion of the outermost layer becomes uniform, the corrosion resistance becomes sufficiently high, and the connection resistance between the electrodes is sufficiently increased. Can be lowered.

The thickness of the metal portion can be measured by observing the cross section of the metal-coated particles, for example, using a transmission electron microscope (TEM). Regarding the thickness of the metal portion, it is preferable to calculate the average value of the thickness of any metal portion at five locations as the thickness of the metal portion of one metal-coated particle, and the average value of the thickness of the entire metal portion is one. It is more preferable to calculate as the thickness of the metal portion of the metal-coated particles. The thickness of the metal portion is preferably obtained by calculating the average value of the thickness of the metal portion of each metal-coated particle for 10 arbitrary metal-coated particles.

Of the total surface area of the outer surface of the base particles of 100%, the surface area of the portion covered with the metal portion is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, and particularly preferably 80% or more. 90% or more, most preferably 100%.

<Core material and protrusions>
The metal-coated particles preferably have protrusions on the outer surface of the metal portion. It is preferable that the number of the protrusions is plurality. In this case, the metal-coated particles and the metal particles can be sintered more effectively.

It is preferable that the metal-coated particles include a plurality of core substances in which the surface of the metal portion is raised in the metal portion so as to form a plurality of protrusions in the metal portion.

As a method of forming the above-mentioned protrusions, a method of forming a metal portion by electroless plating after adhering a core substance to the surface of the base particle, and a method of forming a metal portion by electroless plating on the surface of the base particle. After that, a method of adhering a core substance and further forming a metal portion by electroless plating can be mentioned. Further, it is not necessary to use the core substance in order to form the protrusions.

As another method for forming the protrusions, there is a method of adding a core substance in the middle of forming a metal portion on the surface of the base particle. Further, in order to form protrusions, a metal portion is formed on the base particles by electroless plating without using the above-mentioned core substance, and then plating is deposited in the form of protrusions on the surface of the metal portion, and further electroless plating is performed. You may use a method of forming a metal portion by means of.

As a method of adhering the core substance to the surface of the base particle, the core substance is added to the dispersion liquid of the base particle, and the core substance is accumulated and adhered to the surface of the base particle by van der Waals force. Examples thereof include a method of adding a core substance to a container containing the base particles and attaching the core substance to the surface of the base particles by a mechanical action such as rotation of the container. From the viewpoint of controlling the amount of the core substance to be adhered, the method of adhering the core substance to the surface of the base material particles is a method of accumulating and adhering the core substance to the surface of the base material particles in the dispersion liquid. preferable.

Examples of the substance constituting the core substance include a conductive substance and a non-conductive substance. Examples of the conductive substance include metals, metal oxides, conductive non-metals such as graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene and the like. Examples of the non-conductive substance include silica, titanium oxide, barium titanate, tungsten carbide, alumina and zirconia. From the viewpoint of more effectively removing the oxide film, it is preferable that the core substance is hard. From the viewpoint of further effectively lowering the connection resistance between the electrodes, the core material is preferably a metal.

The above metals are not particularly limited. Examples of the metals include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and tin-lead alloys. Examples thereof include alloys composed of two or more kinds of metals such as tin-copper alloy, tin-silver alloy, tin-lead-silver alloy and tungsten carbide. From the viewpoint of further effectively lowering the connection resistance between the electrodes, the metal is preferably nickel, copper, silver or gold. The metal may be the same as or different from the metal constituting the metal portion.

The shape of the core substance is not particularly limited. The shape of the core material is preferably lumpy. Examples of the core material include particulate lumps, agglomerates in which a plurality of fine particles are aggregated, and amorphous lumps.

The particle size of the core substance is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. When the particle size of the core substance is not less than the lower limit and not more than the upper limit, the connection resistance between the electrodes can be further effectively lowered.

The particle size of the core material is preferably an average particle size, more preferably a number average particle size. The particle size of the core substance is determined by observing 50 arbitrary core substances with an electron microscope or an optical microscope, calculating the average value of the particle size of each core substance, or using a particle size distribution measuring device. In observation with an electron microscope or an optical microscope, the particle size of the core material per piece is determined as the particle size in the equivalent circle diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 core materials in the equivalent circle diameter is substantially equal to the average particle diameter in the equivalent sphere diameter. In the particle size distribution measuring device, the particle size of the core substance per piece is obtained as the particle size in the equivalent diameter of a sphere. The average particle size of the core material is preferably calculated using a particle size distribution measuring device.

From the viewpoint of more effectively exerting the effect of the present invention, the surface area of the portion having the protrusions is preferably 25% or more, more preferably 30% or more, in the total surface area of the outer surface of the metal portion of 100%. , More preferably 50% or more. The surface area of the portion having the protrusion may be 95% or less, 90% or less, or 80% or less.

The number of the protrusions per metal-coated particle is preferably 3 or more, more preferably 5 or more. The upper limit of the number of the protrusions is not particularly limited. The upper limit of the number of protrusions can be appropriately selected in consideration of the particle size of the metal-coated particles and the like. When the number of the protrusions is at least the above lower limit, the connection resistance between the electrodes can be further effectively lowered.

The number of protrusions can be calculated by observing arbitrary metal-coated particles with an electron microscope or an optical microscope. The number of protrusions is preferably determined by observing 50 arbitrary metal-coated particles with an electron microscope or an optical microscope and calculating the average value of the number of protrusions in each metal-coated particles.

The height of the protrusions is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. When the height of the protrusion is not less than the lower limit and not more than the upper limit, the connection resistance between the electrodes can be further effectively lowered.

The height of the protrusions can be calculated by observing the protrusions on any metal-coated particles with an electron microscope or an optical microscope. For the height of the protrusions, it is preferable to calculate the average value of the heights of all the protrusions per metal-coated particle as the height of the protrusions of one metal-coated particle. The height of the protrusions is preferably obtained by calculating the average value of the heights of the protrusions of each metal-coated particle for 50 arbitrary metal-coated particles.

<Other details of metal-coated particles>
The particle size of the metal-coated particles is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 3 μm or more, preferably 100 μm or less, more preferably 80 μm or less, still more preferably 60 μm or less. When the particle diameter of the metal-coated particles is not less than the above lower limit and not more than the above upper limit, the joining reliability of the members to be joined is further increased, and the variation in the spacing between the members to be joined is further reduced. Further, when the particle diameter of the metal-coated particles is equal to or larger than the above lower limit, the thickness of the joint portion arranged between the members to be joined can be further increased, and the heat dissipation and joining reliability of the joint portion can be further improved. It can be further enhanced. When the particle diameter of the metal-coated particles is not more than the upper limit, the distance between the electrodes can be further reduced, and the bonded structure can be made smaller and thinner.

When the metal-coated particles are used as a spacer, the particle size of the metal-coated particles is preferably 20 μm or more, more preferably 30 μm or more, still more preferably 40 μm or more, preferably 100 μm or less, and more preferably 80 μm or less. , More preferably 60 μm or less.

The particle size of the metal-coated particles is preferably an average particle size, and preferably a number average particle size. For the particle size of the metal-coated particles, for example, 50 arbitrary metal-coated particles are observed with an electron microscope or an optical microscope, the average value of the particle size of each metal-coated particle is calculated, or a particle size distribution measuring device is used. It is required. In observation with an electron microscope or an optical microscope, the particle size of each metal-coated particle is determined as the particle size in the equivalent circle diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 metal-coated particles in the equivalent circle diameter is substantially equal to the average particle diameter in the equivalent sphere diameter. In the particle size distribution measuring device, the particle size of each metal-coated particle is determined as the particle size in the equivalent diameter of a sphere. The average particle size of the metal-coated particles is preferably calculated using a particle size distribution measuring device.

The compressive elastic modulus (20% K value) when the metal-coated particles are compressed by 20% at 25 ° C. is preferably 100 N / mm ² or more, more preferably 500 N / mm ² or more, and preferably 20000 N / mm ² . Below, it is more preferably 10000 N / mm ² or less. When the compressive elastic modulus is equal to or higher than the lower limit and lower than the upper limit, the flexibility of the metal-coated particles can be further increased, and cracks in the joint and the joint target due to the generation of warpage and thermal stress of the member to be joined can be obtained. The occurrence of interface peeling at the interface between the member and the joint can be effectively suppressed.

The compressive elastic modulus (20% K value) can be measured as follows.

Using a microcompression tester, compress one metal-coated particle with a smooth indenter end face of a cylinder (diameter 100 μm, made of diamond) under the conditions of 25 ° C., compression rate 0.3 mN / sec, and maximum test load 20 mN. .. At this time, the load value (N) and the compressive displacement (mm) are measured. From the obtained measured values, the compressive elastic modulus (20% K value) can be obtained by the following formula. As the microcompression tester, "Fisherscope H-100" manufactured by Fisher Co., Ltd. is used. It is preferable to calculate by arithmetically averaging the compressive elastic modulus (20% K value) of the metal-coated particles and the compressive elastic modulus (20% K value) of 50 arbitrarily selected metal-coated particles.

20% K value (N / mm ² ) = (3/2 ^1/2 ) ・ F ・ S ^-3/2・ R- ^{1 / 2}
F: Load value (N) when the metal-coated particles are compressed and deformed by 20%.
S: Compressive displacement (mm) when the metal-coated particles are compressed and deformed by 20%.
R: Radius of metal-coated particles (mm)

The compressive elastic modulus universally and quantitatively represents the hardness of the metal-coated particles. By using the compressive modulus, the hardness of the metal-coated particles can be quantitatively and uniquely expressed.

The content of the metal-coated particles in 100% by weight of the sintering composition is preferably 0.005% by weight or more, more preferably 0.5% by weight or more, still more preferably 1% by weight or more, preferably 30. By weight or less, more preferably 20% by weight or less, still more preferably 15% by weight or less. When the content of the metal-coated particles is not less than the above lower limit and not more than the above upper limit, the effect of the present invention can be exhibited even more effectively.

The shape of the metal-coated particles is not particularly limited. The shape of the metal-coated particles may be spherical, non-spherical, or flat.

The metal-coated particles may or may not have an insulating substance arranged on the outer surface of the metal portion. It is preferable that the metal-coated particles do not have an insulating substance arranged on the outer surface of the metal portion.

(Binder resin)
The above-mentioned sintering composition may contain a binder resin. The binder resin is not particularly limited. As the binder resin, a known insulating resin is used.

The binder resin preferably contains a thermoplastic component (thermoplastic compound) or a curable component, and more preferably contains a curable component. Examples of the curable component include a photocurable component and a thermosetting component. The binder resin preferably contains a thermoplastic component or a thermosetting component, and preferably contains a thermosetting component. The photocurable component preferably contains a photocurable compound and a photopolymerization initiator. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent. Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, elastomers and the like. Only one kind of the binder resin may be used, or two or more kinds thereof may be used in combination.

Examples of the vinyl resin include vinyl acetate resin, acrylic resin, styrene resin and the like. Examples of the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins. Examples of the curable resin include epoxy resin, urethane resin, silicone resin, polyimide resin, unsaturated polyester resin and the like. The curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymer include a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated additive of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene. -Hydrogen additives for styrene block copolymers and the like can be mentioned. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

The content of the binder resin in 100% by weight of the sintering composition is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, still more preferably 0.5% by weight or more, and particularly preferably. Is 1% by weight or more, preferably 30% by weight or less, and more preferably 20% by weight or less. When the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the bonding reliability can be further improved.

(Flux component)
The above-mentioned sintering composition may contain a flux component. The flux component means an organic component capable of exerting an action of removing the oxide film, and the type thereof is not particularly limited.

Examples of the flux component include organic solvents, rosins, activators, thixotropic agents, antioxidants and the like. Only one kind of the flux component may be used, or two or more kinds thereof may be used in combination.

Examples of the organic solvent include alcohol compounds such as ethanol and terpineol; ketone compounds such as acetone, methyl ethyl ketone and cyclohexanone; aromatic hydrocarbon compounds such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol and methyl. Glycol ether compounds such as carbitol, butyl carbitol, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether; ethyl acetate, butyl acetate , Butyl lactic acid, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, tetraethylene glycol, ester compounds such as propylene carbonate; octane, Examples thereof include aliphatic hydrocarbon compounds such as decane; lactam such as N-methyl-2-pyrrolidone; nitriles such as phenyl acetonitrile; and petroleum-based solvents such as petroleum ether and naphtha. Only one kind of the organic solvent may be used, or two or more kinds may be used in combination.

Examples of the rosin include isopimaric acid, palastolic acid, dihydropimaric acid, pimaric acid, tetrahydroabietic acid, neoavietic acid, dihydroabietic acid, dehydroabietic acid and the like.

Examples of the active agent include glutaric acid, succinic acid, maleic acid, glycolic acid, propionic acid, caproic acid, azelaic acid, diphenylacetic acid, phthalic acid, benzoic acid, sebacic acid, aminodecanoic acid, anisic acid, picolinic acid and iodosalicylic acid. , Organic acid salts such as dibromosalicylic acid, pentane-1,5-dicarboxylic acid, amine salts such as triethanolamine, amine chloride hydride, amine bromide hydride and the like.

Examples of the thixo agent include natural fats and oils, hardened castor oil, ethylene bisstearic acid amide, N, N'-distearyladipate amide, hexamethylenebisoleic acid amide, N, N'-ethylenebis-12-hydroxystearylamide, and the like. Examples thereof include 12-hydroxystearic acid, 12-hydroxystearic acid triglyceride, 1,2,3,4-dibenzylidene-D-sorbitol and the like.

Examples of the antioxidant include a phosphoric acid-based antioxidant, a hydroxylamine-based antioxidant, a hindered phenol-based antioxidant, a nitrogen-containing heterocyclic compound such as a benzotriazole compound and an imidazole compound, a mercaptan compound, a thiazole compound, and an organic substance. Examples thereof include sulfur-containing compounds such as disulfide compounds.

The content of the flux component in 100% by weight of the sintering composition is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 30% by weight or less, and more preferably. It is 25% by weight or less. When the content of the flux component is not less than the above lower limit and not more than the above upper limit, the action of removing the oxide film can be effectively exerted.

(Other ingredients)
The sintering composition may contain a metal component capable of transitional liquid phase sintering, metal-coated particles, a binder resin, and a flux component other than these four components. Examples of the other components include fillers, bulking agents, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, heat stabilizers, light stabilizers, ultraviolet absorbers, lubricants, antistatic agents and flame retardants. And various additives such as.

(Other details of the sintering composition)
The sintering composition is preferably a bonding material. The sintering composition is preferably a transitional liquid phase sintering type bonding material. The sintered composition can be sintered to obtain a sintered body.

The properties of the sintering composition are preferably in the form of a paste. The above-mentioned sintering composition is preferably a paste-like sintering composition.

In the present specification, the paste form means that there is fluidity.

The viscosity of the sintering composition at 25 ° C. is preferably 10 Pa · s or more, more preferably 20 Pa · s or more, preferably 300 Pa · s or less, and more preferably 200 Pa · s or less. When the viscosity of the sintering composition at 25 ° C. is not less than the above lower limit and not more than the above upper limit, the bonding reliability can be further effectively improved. The viscosity can be appropriately adjusted depending on the type and amount of the compounding components.

The viscosity can be measured at 25 ° C. and 5 rpm using, for example, an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.).

The paste-like composition is obtained by mixing, for example, a metal component capable of transitional liquid phase sintering, metal-coated particles, a binder resin, and other components to be blended as necessary, and stirring the mixture. Can be obtained at.

(Joint structure)
A bonded structure can be produced by using the above-mentioned sintering composition (bonding material).

The joining structure includes a first joining target member, a second joining target member, and a joining portion that joins the first joining target member and the second joining target member.

In the joint structure, the joint portion is preferably formed of a cured product of the joint material, and more preferably formed of a sintered body of the joint material.

The joint material is heated to form the joint. The heating conditions of the bonding material can be appropriately changed depending on the compounding composition of the bonding material. The heating temperature is preferably 100 ° C. or higher, more preferably 150 ° C. or higher, preferably 400 ° C. or lower, and more preferably 300 ° C. or lower. The heating time is preferably 0.5 minutes or longer, more preferably 1 minute or longer, preferably 90 minutes or shorter, and more preferably 30 minutes or shorter. The bonding material may be heated stepwise. For example, the heating conditions for the bonding material are 100 ° C. or higher and 200 ° C. or lower for 0.5 minutes or longer and 90 minutes or shorter, and then 200 ° C. or higher and 400 ° C. or lower for 0.5 minutes or longer and 90 minutes or shorter. There may be.

The sintering of the bonding material is preferably performed in a low oxygen concentration atmosphere. Under a low oxygen concentration atmosphere means that the oxygen concentration is 1000 ppm or less. It is more preferable that the sintering of the bonding material is performed in a low oxygen concentration atmosphere having an oxygen concentration of 500 ppm or less.

Further, the sintering of the bonding material may be performed in a reducing gas atmosphere or in an inert gas atmosphere. Examples of the reducing gas include formic acid gas, hydrogen gas, carbon monoxide gas, hydrocarbon gas and the like. Examples of the inert gas include nitrogen gas, helium gas, argon gas, forming gas and the like.

Examples of the first joining target member and the second joining target member include support members and elements. It is preferable that the first joining target member is a support member and the second joining target member is an element. The support member is not particularly limited, but is used in lead frames, printed circuit boards, FR4 boards, flexible printed circuit boards, stretchable boards, glass epoxy boards, glass boards, various heat dissipation boards, pre-wired silicon wafers, and wafer level CSPs. Examples include the rewiring layer to be used. The element is not particularly limited, and examples thereof include active elements such as semiconductor chips, transistors, LED chips, diodes, light emitting diodes, and thyristers, and passive elements such as capacitors, resistors, resistance arrays, coils, and switches. The element is preferably a power semiconductor element.

The junction structure preferably constitutes a semiconductor device, and more preferably constitutes a power semiconductor device.

Specific examples of semiconductor devices include diodes, thyristors, MOS gate drivers, power switches, power MOSFETs, IGBTs, shotkey diodes, power modules equipped with fast recovery diodes, RFID modules, LED modules, transmitters, etc. Examples include amplifiers.

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.

The following metal components capable of transitional liquid phase sintering were prepared.

Metal particles containing copper as the main metal:
Copper particles A ("MA-C05K-2" manufactured by Mitsui Mining & Smelting Co., Ltd., particle diameter 5 μm)
Copper particles B ("MA-CKU" manufactured by Mitsui Mining & Smelting Co., Ltd., particle diameter 10 μm)

Metal particles containing tin as the main metal:
Tin-silver-copper alloy particles (SAC particles, "ST-5" manufactured by Mitsui Mining & Smelting Co., Ltd., particle diameter 5 μm)
Tin-bismuth alloy particles (Sn-Bi alloy particles, "ST-5" manufactured by Mitsui Mining & Smelting Co., Ltd., particle diameter 5 μm)

The following metal-coated particles prepared according to the following production method were prepared.

Metal-coated particles A (metal-coated particles having a particle diameter of 5.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles B (metal-coated particles having a particle diameter of 2.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles C (metal-coated particles having a particle diameter of 10.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles D (metal-coated particles having a particle diameter of 20.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles E (metal-coated particles having a particle diameter of 30.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles F (metal-coated particles having a particle diameter of 5.6 μm and a nickel layer having a thickness of 100 nm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles G (metal-coated particles having a particle diameter of 5.6 μm and a nickel layer having a thickness of 100 nm and a tin layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles H (metal-coated particles having a particle diameter of 5.6 μm and a nickel layer having a thickness of 280 nm and a gold layer having a thickness of 20 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles I (metal-coated particles having a particle diameter of 5.4 μm and a nickel layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles J (metal-coated particles having a particle diameter of 5.6 μm and a nickel layer having a thickness of 100 nm and a silver layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).
Metal-coated particles K (metal-coated particles having a particle diameter of 5.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of acrylic resin).
Metal-coated particles L (metal-coated particles having a particle diameter of 5.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of an epoxy resin).
Metal-coated particles M (metal-coated particles having a particle diameter of 5.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of a polyimide resin).
Metal-coated particles N (metal-coated particles having a particle diameter of 5.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of a bismaleimide resin).
Metal-coated particles O (metal-coated particles having a particle diameter of 5.4 μm and a copper layer having a thickness of 200 nm formed on the surface of silicone particles formed of silicone)
Metal-coated particles P (metal-coated particles having a particle diameter of 40.4 μm and a copper layer having a thickness of 200 nm formed on the surface of resin particles formed of a divinylbenzene copolymer).

The particle diameters of the metal particles and the metal-coated particles, the thickness of the metal portion, and the like are values measured according to the evaluation method described later.

(Method for producing metal-coated particles A)
As the base particle A, divinylbenzene copolymer resin particles (base particle A, “SP-205” manufactured by Sekisui Chemical Co., Ltd., particle diameter 5 μm) were prepared. 10 parts by weight of the base particle A was dispersed in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the base particle A was taken out by filtering the solution. .. Next, the base particle A was added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surface of the base particle A. After thoroughly washing the surface-activated substrate particles A with water, the particles A were added to 500 parts by weight of distilled water and dispersed to obtain a dispersion liquid. Next, 2 g of a Ni particle slurry (average particle diameter 150 nm) was added to the dispersion over 3 minutes to obtain a suspension containing the base particles to which the core material of the protrusions was attached.

It also contains 0.50 mol / L copper sulfate, 1.38 mol / L dimethylamine borane, 1.20 mol / L ethylenediamine tetrasodium acetate, 0.02 mol / L PEG1000 and 0.005 mol / L bipyridyl. A non-electrolytic copper plating solution (pH 9.0) was prepared.

While stirring the obtained suspension at 60 ° C., the electroless copper plating solution was gradually added dropwise to the suspension to perform electroless copper plating. Then, the particles were taken out by filtering the suspension, washed with water, and dried to place a copper layer (200 nm) on the surface of the base particle A.

In this way, the metal-coated particles A having protrusions on the outer surface were produced.

(Method for producing metal-coated particles B)
Similar to the metal-coated particles A, except that divinylbenzene copolymer resin particles (base particle B, “SP-202” manufactured by Sekisui Chemical Co., Ltd., particle diameter 2 μm) were used as the base particle B. Metal-coated particles B were produced.

(Method for producing metal-coated particles C)
Similar to the metal-coated particles A, except that divinylbenzene copolymer resin particles (base particle C, “SP-210” manufactured by Sekisui Chemical Co., Ltd., particle diameter 10 μm) were used as the base particle C. Metal-coated particles C were produced.

(Method for producing metal-coated particles D)
Similar to the metal-coated particles A, except that divinylbenzene copolymer resin particles (base particle D, “SP-220” manufactured by Sekisui Chemical Co., Ltd., particle diameter 20 μm) were used as the base particle D. Metal-coated particles D were produced.

(Method for producing metal-coated particles E)
Similar to the metal-coated particles A, except that divinylbenzene copolymer resin particles (base particle E, “SP-230” manufactured by Sekisui Chemical Co., Ltd., particle diameter 30 μm) were used as the base particles E. Metal-coated particles E were produced.

(Method for producing metal-coated particles F)
The metal-coated particles F were produced in the same manner as the metal-coated particles A, except that the copper layer was formed on the nickel layer in place of the copper layer by the following procedure.

An electroless nickel solution (pH 8.5) containing 0.21 mol / L nickel sulfate, 0.92 mol / L dimethylamine borane and 0.33 mol / L sodium citrate trihydrate as an electroless nickel plating solution. Prepared.

Similar to the metal-coated particles A, a suspension containing the base particles to which the core material of the protrusions was attached was obtained. While stirring the obtained suspension at 60 ° C., the electroless nickel plating solution was gradually added dropwise to the suspension to perform electroless nickel plating, and a nickel layer (100 nm) was formed on the surface of the base particle A. Was placed. Then, the suspension was filtered and washed with water to obtain a suspension of metal-coated particles in which a nickel layer was arranged on the base particle A.

The obtained suspension was electrolessly copper-plated in the same process as the metal-coated particles A. The suspension was then filtered to remove the particles, washed with water and dried to place a copper layer (200 nm) on the outer surface of the nickel layer (100 nm).

In this way, the metal-coated particles F having protrusions on the outer surface were produced.

(Method for producing metal-coated particles G)
Metal-coated particles G were produced in the same manner as the metal-coated particles F, except that a tin layer was formed on the nickel layer in place of the copper layer by the following procedure.

An electroless Sn plating solution (pH 9.0) containing 0.50 mol / L tin sulfate, 1.50 mol / L titanium trichloride (III) and 1.80 mol / L ethylenediamine tetrasodium acetate was prepared.

In the same process as the metal-coated particles F, a suspension of the metal-coated particles in which the nickel layer was arranged on the base particle A was obtained.

While stirring the obtained suspension at 60 ° C., the electroless tin plating solution was gradually added dropwise to the suspension to perform electroless tin plating. Then, the particles were taken out by filtering the suspension, washed with water, and dried to place a tin layer (200 nm) on the outer surface of the nickel layer (100 nm).

In this way, the metal-coated particles G having protrusions on the outer surface were produced.

(Method for producing metal-coated particles H)
Metal-coated particles H were produced in the same manner as the metal-coated particles F, except that a gold layer was formed on the nickel layer in place of the copper layer by the following procedure.

An electroless nickel solution (pH 8.5) containing 0.59 mol / L nickel sulfate, 2.58 mol / L dimethylamine borane and 0.92 mol / L sodium citrate trihydrate as an electroless nickel plating solution. Prepared.

Further, the electroless gold containing 2 g / L of gold potassium cyanide, 20 g / L of sodium citrate, 3.0 g / L of ethylenediamine tetraacetate disodium and 20 g / L of sodium hydroxide as the electroless gold plating solution. A plating solution (pH 6.5) was prepared.

As with the metal-coated particles A, a suspension containing the base particles to which the core material of the protrusions is attached is prepared, and the obtained suspension is stirred at 60 ° C. while the above electroless nickel plating solution is applied. It was gradually dropped onto the turbid liquid, electroless nickel plating was performed, and a nickel layer (280 nm) was placed on the surface of the base particle A. Then, the suspension was filtered and washed with water, and the particles were recovered again to obtain a suspension of metal-coated particles in which a nickel layer was arranged on the base particles A.

Next, the electroless gold plating solution was gradually added dropwise to the suspension while stirring the obtained suspension at 55 ° C. to perform electroless gold plating. Then, the particles were taken out by filtering the suspension, washed with water, and dried to place a gold layer (20 nm) on the outer surface of the nickel layer (280 nm).

In this way, the metal-coated particles H having protrusions on the outer surface were produced.

(Method for producing metal-coated particles I)
Metal-coated particles I were produced in the same manner as the metal-coated particles A, except that the nickel layer was formed by the following procedure.

As the electroless nickel plating solution, an electroless nickel solution (pH 8.5) containing 0.42 mol / L nickel sulfate, 1.84 mol / L dimethylamine borane and 0.66 mol / L sodium citrate trihydrate. Prepared.

As with the metal-coated particles A, a suspension containing the base particles to which the core material of the protrusions is attached is prepared, and the obtained suspension is stirred at 60 ° C. while the above electroless nickel plating solution is applied. It was gradually dropped onto the turbid liquid, electroless nickel plating was performed, and a nickel layer (200 nm) was placed on the surface of the base particle A.

In this way, the metal-coated particles I having protrusions on the outer surface were produced.

(Method for producing metal-coated particles J)
Metal-coated particles J were produced in the same manner as the metal-coated particles F, except that a silver layer was formed on the nickel layer in place of the copper layer by the following procedure.

As an electroless silver plating solution, a silver plating solution (D1) prepared by adjusting a mixed solution containing 15 g / L silver nitrate, 50 g / L succinimide and 20 g / L formaldehyde to pH 8.0 with aqueous ammonia was prepared. did.

A suspension of metal-coated particles in which a nickel layer was arranged on the base particle A was obtained in the same process as that of the non-metal-coated particles F.

While stirring the obtained suspension at 60 ° C., the electroless silver plating solution was gradually added dropwise to the suspension to perform electroless tin plating. Then, the particles were taken out by filtering the suspension, washed with water, and dried to place a silver layer (200 nm) on the outer surface of the nickel layer (100 nm).

In this way, the metal-coated particles J having protrusions on the outer surface were produced.

(Method for producing metal-coated particles K)
Metal-coated particles K were produced in the same manner as the metal-coated particles A, except that acrylic resin particles (base particle K, “ELP” manufactured by Sekisui Chemical Co., Ltd., particle diameter 5 μm) were used as the base particles K. did.

(Method for producing metal-coated particles L)
Metal-coated particles K were produced in the same manner as the metal-coated particles A, except that epoxy resin particles (base particle L, “FSD” manufactured by Sekisui Chemical Co., Ltd., particle diameter 5 μm) were used as the base particles L. did.

(Method for producing metal-coated particles M)
Metal-coated particles M were produced in the same manner as the metal-coated particles A, except that polyimide resin particles (base particle M, "P84NT" manufactured by Daicel Evonik, particle diameter 5 μm) were used as the base particles M. did.

(Method for producing metal-coated particles N)
The metal-coated particles N were prepared in the same manner as the metal-coated particles A, except that the base particles N were bismaleimide resin particles (base particles N, “BMI” manufactured by Sekisui Chemical Co., Ltd., particle diameter 5 μm). Made.

(Method for producing metal-coated particles O)
Metal-coated particles O were produced in the same manner as the metal-coated particles A, except that silicone particles (base particle N, “SLC” manufactured by Sekisui Chemical Co., Ltd., particle diameter 5 μm) were used as the base particles O. ..

(Method for producing metal-coated particles P)
Similar to the metal-coated particles A, except that divinylbenzene copolymer resin particles (base particle P, “SP-240” manufactured by Sekisui Chemical Co., Ltd., particle diameter 40 μm) were used as the base particles P. Metal-coated particles P were produced.

(Example 1)
(1) Preparation of Sintering Composition The following components were stirred and mixed using a planetary stirrer to obtain a sintering composition (bonding material).

59.9 parts by weight of copper particles A
18 parts by weight of copper particles B
15 parts by weight of SAC particles 0.1 parts by weight of metal-coated particles A
3.3 parts by weight of diethylene glycol monohexyl ether 3.2 parts by weight of rosin (dehydroabietic acid)
0.25 parts by weight of activator (glutaric acid)
0.25 parts by weight thixotropic agent (12-hydroxystearic acid)

(2) Preparation of Joined Structure A copper plate (length 2 cm x width 2 cm x thickness 1 mm) was prepared as the first member to be joined. As the second member to be joined, a silicon chip (length 2 mm × width 2 mm) having an Au-plated back surface was prepared.

Using a metal mask (opening size: length 2.5 mm × width 2.5 mm × height 50 μm), the obtained paste-like composition (bonding material) is applied onto a copper plate to form a bonding material layer. did. Then, silicon chips were laminated on the bonding material layer to obtain a laminated body. The obtained laminate is heated in a reflow furnace at 250 ° C. for 1 minute in a nitrogen atmosphere to sintered copper particles A, copper particles B, SAC particles and metal-coated particles A contained in the bonding material. Then, a bonded portion was formed, and the copper plate and the silicon chip were bonded by a sintered body to obtain a bonded structure.

(Examples 2 to 23 and Comparative Examples 1 and 2)
A sintering composition and a bonded structure were obtained in the same manner as in Example 1 except that the types and blending amounts of the metal particles and the metal-coated particles were changed as shown in Tables 1 to 5. In the sintering compositions obtained in Examples 7 and 8, the metal-coated particles satisfactorily exhibit the function as a spacer. Further, in Examples 2 to 23 and Comparative Examples 1 and 2, the same amounts of diethylene glycol monohexyl ether, rosin (dehydroabietic acid), activator (glutaric acid), and thixotropy (12-hydroxystearic acid) as in Example 1 were used. ) Is blended.

(evaluation)
(1) Particle size of metal particles, substrate particles and metal-coated particles For metal particles, the particle size of about 100,000 metal particles was measured using a particle size distribution measuring device (“Multisizer4” manufactured by Beckman Coulter). The average value was taken as the particle size of the metal particles. The particle size of the base material particles and the metal-coated particles was measured in the same manner, and the average value was taken as the particle size of the base material particles and the metal-coated particles.

(2) Thickness of Metal Part The thickness of the metal part was measured by observing the cross section of the obtained metal-coated particles using a transmission electron microscope (TEM) (“JEM2100” manufactured by JEOL Ltd.). The average value of the thickness of any metal portion at five locations was calculated as the thickness of the metal portion of one silver-containing particle. Next, the thickness of the metal portion was calculated for each of the 10 arbitrary metal-coated particles, and the average value thereof was taken as the thickness of the metal portion.

(3) Join reliability test (die shear strength)
The obtained bonded structure was placed in a thermal shock tester (“TSE-11-A” manufactured by ESPEC CORPORATION), and a thermal cycle test in which cooling and heating were repeated was performed. The test conditions were a total of 1000 cycles, with the operation of maintaining at −40 ° C. for 30 minutes and then maintaining at 125 ° C. for 30 minutes as one cycle. After returning the inside of the thermal shock tester to room temperature (25 ° C.), the bonded structure was taken out.

For the joint structure before and after the cold cycle test, the die shear strength was measured using a bond tester (“Dage 4000” manufactured by Nordson) under the conditions of a measurement speed of 100 μm / s and a measurement height of 100 μm.

Also, from the obtained die-share strength, the maintenance rate of the die-share strength was calculated from the following formula.

Maintenance rate of die-share strength (%) = (Die-share strength after cold cycle test / Die-share strength before cold cycle test) x 100

The results are shown in Tables 1 to 5 below.

1,1A, 1B ... Metal-coated particles 1Ba ... Protrusions 2 ... Base particles 3,3A, 3B ... Metal parts 3Ba ... Protrusions 4 ... Core material 31A, 31B ... First metal parts 31Ba ... Projections 32A, 32B ... Second Metal part 32Ba ... protrusion

Claims (14)

1. It contains a metal component capable of transitional liquid phase sintering and a plurality of metal-coated particles.
   The metal component contains two or more kinds of metal particles having different main metals from each other.
   A composition for sintering in which the metal-coated particles include a base particle different from the metal particle and a metal portion arranged on the surface of the base particle.
2. The sintering composition according to claim 1, wherein the metal component contains metal particles containing copper as a main metal and metal particles containing tin as a main metal.
3. The sintering composition according to claim 1 or 2, wherein the base particles of the metal-coated particles are resin particles.
4. 3. The sintering composition according to item 1.
5. The sintering composition according to any one of claims 1 to 4, wherein the content of the metal-coated particles is 0.005% by weight or more and 30% by weight or less.
6. The sintering composition according to any one of claims 1 to 5, wherein the compression elastic modulus when the metal-coated particles are compressed by 20% at 25 ° C. is 100 N / mm ² or more and 20000 N / mm ² or less.
7. The sintering composition according to any one of claims 1 to 6, wherein the metal-coated particles have a particle size of 1 μm or more and 100 μm or less.
8. The sintering composition according to any one of claims 1 to 7, wherein the metal portion of the metal-coated particles has protrusions on the outer surface.
9. The sintering composition according to any one of claims 1 to 8, which contains a flux component.
10. Contains binder resin,
    The sintering composition according to any one of claims 1 to 9, wherein the binder resin contains a thermoplastic component or a thermosetting component.
11. The sintering composition according to any one of claims 1 to 10, which is a bonding material.
12. A sintered body obtained by sintering the sintering composition according to any one of claims 1 to 11.
13. The first member to be joined and
    The second member to be joined and
    A joint portion for joining the first joining target member and the second joining target member is provided.
    A joint structure in which the joint portion is formed of the sintered body according to claim 12.
14. The first member to be joined is a support member.
    The joining structure according to claim 13, wherein the second joining target member is an element.

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