TWI783938B - Connection structure, particles containing metal atoms and composition for connection - Google Patents

Abstract

Provided are a bonded structure, metal atom-containing particles for assembling the bonded structure, and a composition for connection, wherein the bonded structure suppresses occurrence of warpage and cracks even when stress is applied.

The bonded structure A is equipped with the adhesive layer 50 containing the particle 10 containing a metal atom, and the sintered body 20 of a metal particle. The metal atom-containing particles 10 are in contact with the sintered body 20 through chemical bonding, and in the section of the adhesive layer 50, more than 5% of the periphery of the metal atom-containing particles 10 are in contact with the sintered body.

Description

Connection structure, particles containing metal atoms and composition for connection

The present invention relates to a connection structure, particles containing metal atoms used to form the connection structure, and a composition for connection.

Conventionally, in a non-insulated semiconductor device which is one of power semiconductor devices (power devices) used in an inverter or the like, it is known to use a connecting member for fixing a semiconductor element. Such a connecting member can also become one of electrodes of a semiconductor device. For example, in a semiconductor device in which a power transistor is mounted on a connecting member using a Sn-Pb solder material, the connecting member (substrate) connecting two members to be connected serves as a collector of the power transistor.

In recent years, it is expected to further improve performances such as heat resistance temperature, thermal conductivity, volume resistance, etc. of the above-mentioned connected structures such as semiconductor devices. Therefore, various studies have been conducted in the industry on methods of assembling connection structures such as semiconductor devices using materials other than the above-mentioned solder materials. As one example, a method of assembling a bonded structure using a material containing a metal having a small particle size as a connection material has been proposed (for example, Patent Document 1, etc.). This type of connecting material utilizes the following properties of metal particles, that is, if the particle size of the metal particle is reduced to a size of 100 nm or less to reduce the number of constituent atoms, the ratio of the surface area to the particle volume increases rapidly, and the melting point or The sintering temperature is greatly reduced compared with the bulk state. For example, metal particles with an average particle size of 100 nm or less whose surface is coated with organic matter can be used as a connecting material, and the organic matter is decomposed by heating to sinter the metal particles to form an adhesive layer, and the two members to be connected can be bonded together using this adhesive layer. connect. Regarding this connection method, since the metal particles after the connection become bulk metal, the connection generated by the metal bond is obtained at the connection interface, so the heat resistance, connection reliability and heat dissipation of the connection structure can be further improved. .

[Prior Art Literature]

[Patent Document]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2013-55046

However, in a bonded structure such as a semiconductor device, since the adhesive layer connecting two members to be connected is exposed to the conditions of a thermal cycle, stress is applied to the semiconductor wafer and the member to be connected, such as a semiconductor chip, and becomes Warpage and cracks are prone to occur. For example, when a semiconductor device is in operation, a current of several amperes or more flows through the collector, so the transistor chip will heat up and cause thermal stress, which will cause warping of the semiconductor chip. In addition to Patent Document 1, etc., although various connection materials for assembling connection structures have been proposed in the industry, no attempt has been made to improve the connection materials from the viewpoint of preventing warpage and cracks caused by stress. Therefore, it is desired to construct a high-performance bonded structure that suppresses the occurrence of warpage and cracks even when stress is applied, and that is more excellent in durability.

The present invention is made in view of the above circumstances, and an object of the present invention is to provide a bonded structure, metal atom-containing particles for assembling the bonded structure, and a composition for connection, which suppress warpage even when stress is applied to the bonded structure. The occurrence of warping and cracking.

The inventors of the present invention have diligently studied in order to achieve the above object. As a result, it has been found that in order to prevent warping and cracking of the bonded structure, it is important to relax the stress applied to the adhesive layer connecting the two bonded structures of the bonded structure. . Furthermore, as a result of intensive research, it was found that the above-mentioned object can be achieved by making the adhesive layer contain particles having a stress relaxation effect, and making the contact area between the surface of the particles and the sintered body constituting the adhesive layer larger than before, thereby completing the present invention. invention.

That is, the present invention includes, for example, the subject matter described in the following items.

Item 1. A bonded structure comprising an adhesive layer containing particles containing metal atoms and a sintered body of metal particles, wherein the particles containing metal atoms are in contact with the sintered system through chemical bonding, and in the section of the bonding layer, the above-mentioned More than 5% of the peripheral length of the particles of metal atoms is in contact with the sintered body.

Item 2. The bonded structure according to Item 1, wherein the metal atom-containing particle includes a base material particle and a metal part arranged on the surface of the base material particle.

Item 3. The bonded structure according to Item 2, wherein the metal part has a plurality of protrusions on the outer surface.

Item 4. The bonded structure according to Item 3, wherein the average diameter of the base of the protrusion is 3 nm or more and 5000 nm or less.

Item 5. The bonded structure according to Item 3 or 4, wherein the average height of the protrusions is 1 nm or more and 1000 nm or less.

Item 6. The bonded structure according to any one of Items 3 to 5, wherein the protrusions account for 30% or more of the total surface area of the outer surface of the metal portion 100%.

Item 7. The bonded structure according to any one of Items 2 to 6, wherein the total amount of nickel, chromium, platinum, and rhodium in the metal part is 30% by mass or less with respect to the total mass of the metal part.

Item 8. The bonded structure according to any one of Items 2 to 7, wherein the metal portion contains a material selected from the group consisting of gold, silver, tin, copper, germanium, indium, palladium, tellurium, thallium, bismuth, zinc, and arsenic. One or more of the group consisting of , selenium, and alloys containing at least one of these metal elements.

Item 9. The bonded structure according to any one of Items 2 to 8, wherein a plurality of recesses are formed on the surface of the substrate particle.

Item 10. A metal atom-containing particle used in the bonded structure described in any one of Items 1 to 9.

Item 11. A connection composition comprising the metal atom-containing particles and metal particles described in Item 10.

Even if a stress is applied to the bonded structure of the present invention, warpage and cracks are less likely to occur, and thus have excellent durability. Therefore, according to the connection structure of the present invention, for example, a power device with high reliability and excellent performance can be provided.

The metal atom-containing particle of the present invention is suitable as a material for assembling the above connection structure, and can provide a connection structure that is less likely to cause warpage and cracks.

A‧‧‧connection structure

9‧‧‧Gap

10‧‧‧Particles containing metal atoms

11‧‧‧Substrate particles

12‧‧‧Metal Department

12a‧‧‧The first metal part

12b‧‧‧The second metal part

13‧‧‧Protrusion

14‧‧‧Concave

20‧‧‧sintered body

30‧‧‧Gap Control Particles

50‧‧‧adhesion layer

51‧‧‧The first connection object component

52‧‧‧The second connection target member

Fig. 1 shows an example of the bonded structure of this embodiment, and is a schematic cross-sectional view of the bonded structure.

Fig. 2 shows an example of the structure of particles containing metal atoms, which is a schematic diagram of its appearance and a part of its cross-sectional structure.

Fig. 3 shows another example of the structure of particles containing metal atoms, which is a schematic diagram of its appearance and a part of its cross-sectional structure.

Fig. 4 shows another example of the structure of particles containing metal atoms, which is a schematic diagram of its appearance and a part of its cross-sectional structure.

Fig. 5 shows another example of the structure of particles containing metal atoms, which is a schematic diagram of its appearance and a part of its cross-sectional structure.

Fig. 6(a) is a schematic diagram of the cross-sectional structure of the adhesive layer in the bonded structure of this embodiment, and Fig. 6(b) is a schematic diagram of the cross-sectional structure of the adhesive layer in the conventional bonded structure.

Embodiments of the present invention will be described in detail below. In addition, in this specification, the expressions "contains" and "comprises" include the concepts of "contains", "comprises", "substantially consists of" and "consists only of".

FIG. 1 shows an example of a bonded structure according to this embodiment, and schematically shows a cross-sectional structure of the bonded structure.

The bonded structure of this embodiment has an adhesive layer containing metal atom-containing particles and a sintered body of metal particles, the metal atom-containing particles are in contact with the sintered system through chemical bonding, and the metal-containing At least 5% of the peripheral length of the atomic particles is in contact with the above-mentioned sintered body.

Since the bonded structure of this embodiment has a large contact area between the particles containing metal atoms and the sintered body of metal particles, even if stress is applied to the bonded structure, the bonded structure is less likely to cause warping and cracks. Thereby, the bonded structure can have excellent durability.

The bonded structure A shown in FIG. 1 is equipped with the 1st connection object member 51, the 2nd connection object member 52, and the adhesive layer 50 which connects a 1st, 2nd connection object member. The first connection object member 51 and the second connection object member 52 are connected by the adhesive layer 50 .

The bonding layer 50 is formed by containing the particles 10 containing metal atoms and the sintered body 20 of the metal particles. In addition, like the bonded structure A of the present embodiment, the adhesive layer 50 may contain the gap control particles 30 . The particle diameter of the gap control particle 30 is the same as the thickness of the adhesive layer 50 , in other words, it can function as a spacer between the first connection object member 51 and the second connection object member 52 . The gap control particles 30 may be, for example, known conductive particles, but are not limited thereto.

Specific examples of the connection target members 51 and 52 include electronic components such as semiconductor chips, capacitors, and diodes, and electronic components such as circuit boards such as printed circuit boards, flexible printed circuit boards, epoxy glass substrates, and glass substrates. But not limited to these. The above-mentioned connection target members 51 and 52 are preferably electronic components.

In addition, at least one of the first connection object member 51 and the second connection object member 52 is preferably a semiconductor wafer or a semiconductor wafer. That is, the bonded structure A is preferably a semiconductor device.

Hereinafter, the configuration of the metal atom-containing particles 10 contained in the adhesive layer 50 and the sintered body 20 of the metal particles will be described in detail. In addition, in the following description, the code|symbol in FIG. 1 may be abbreviate|omitted.

The type of particles containing metal atoms is not particularly limited as long as they can form a chemical bond with a sintered body of metal particles.

For example, the metal atom-containing particle preferably includes a base material particle and a metal part arranged on the surface of the base material particle. In this case, the metal atom-containing particle becomes easy to form a chemical bond, especially a metal bond, with the sintered body of the metal particle. More specifically, the metal part on the surface of the metal atom-containing particle and the sintered body of the metal particle can form a so-called Solid solution, whereby the metal atom-containing particles are more strongly bonded to the sintered body, and it becomes easier to suppress the occurrence of warpage and cracks in the bonded structure.

The type of the substrate particles is not particularly limited, and examples thereof include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles. The aforementioned substrate particles are preferably resin particles, inorganic particles other than metal particles, or organic-inorganic hybrid particles.

甲醛樹脂、脲甲醛樹脂、酚樹脂、三聚氰胺樹脂、苯胍

樹脂、環氧樹脂、飽和聚酯樹脂、不飽和聚酯樹脂、聚伸苯醚、聚縮醛、聚醯亞胺、聚醯胺醯亞胺、聚醚醚酮、聚醚碸、脲樹脂等。 When the substrate particle is a resin particle, it is suitable to use various organic substances as a material for forming the resin particle. Examples of such materials include polyolefin resins such as polyethylene, polypropylene, polystyrene, silicone resin, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; polymethacrylic acid Acrylic resins such as methyl ester and polymethyl acrylate; polyalkylene terephthalate, polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanidine

Formaldehyde resin, urea-formaldehyde resin, phenol resin, melamine resin, benzoguanidine

Resin, epoxy resin, saturated polyester resin, unsaturated polyester resin, polyphenylene oxide, polyacetal, polyimide, polyamideimide, polyetheretherketone, polyether ketone, urea resin, etc. .

Moreover, resin particle can also be obtained by polymerizing 1 type or 2 or more types of various polymerizable monomers which have an ethylenically unsaturated group. In this case, it is possible to design and synthesize resin particles having arbitrary compression properties suitable for anisotropic conductive materials. In addition, in this case, the hardness of the substrate particles can be easily controlled within an appropriate range. From this point of view, the material of the resin particles is preferably a polymer obtained by polymerizing one or more polymerizable monomers having a plurality of ethylenically unsaturated groups.

When the above-mentioned resin particles are obtained by polymerizing a monomer having an ethylenically unsaturated group, examples of the monomer having an ethylenically unsaturated group include non-crosslinkable monomers and/or crosslinkable monomers. monomer. In addition, in the following description, "(meth)acrylic acid" means either or both of "acrylic acid" and "methacrylic acid", and "(meth)acrylate" means "acrylate" and "methacrylic acid ester". Acrylate "one or both.

酯等(甲基)丙烯酸烷基酯類，(甲基)丙烯酸2-羥基乙酯、(甲基)丙烯酸甘油酯、聚氧乙烯(甲基)丙烯酸酯、(甲基)丙烯酸縮水甘油酯等含氧原子之(甲基)丙烯酸酯類，(甲基)丙烯腈等含腈基單體，(甲基)丙烯酸三氟甲酯、(甲基)丙烯酸五氟乙酯等含鹵素之(甲基)丙烯酸酯類；作為α-烯烴化合物，可列舉二異丁烯、異丁烯、Linealene、乙烯、丙烯等烯 烴類；作為共軛二烯化合物，可列舉異戊二烯、丁二烯等。 Regarding the above-mentioned non-crosslinkable monomers, examples of vinyl compounds include styrene-based monomers such as styrene, α-methylstyrene, and chlorostyrene, methyl vinyl ether, ethyl vinyl ether, Vinyl ethers such as n-propyl vinyl ether, 1,4-butanediol divinyl ether, cyclohexanedimethanol divinyl ether, diethylene glycol divinyl ether, vinyl acetate, vinyl butyrate , vinyl laurate, vinyl stearate and other acid vinyl esters, vinyl chloride, vinyl fluoride and other halogen-containing monomers; as (meth)acrylic acid compounds, methyl (meth)acrylate, (meth) Ethyl acrylate, Propyl (meth)acrylate, Butyl (meth)acrylate, 2-Ethylhexyl (meth)acrylate, Lauryl (meth)acrylate, Cetyl (meth)acrylate, ( Stearyl methacrylate, cyclohexyl (meth)acrylate, iso(meth)acrylate

Alkyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glyceryl (meth)acrylate, polyoxyethylene (meth)acrylate, glycidyl (meth)acrylate, etc. Oxygen-containing (meth)acrylates, (meth)acrylonitrile and other nitrile-containing monomers, (meth)acrylic trifluoromethyl, (meth)pentafluoroethyl acrylate and other halogen-containing (meth)acrylic acid base) acrylates; α-olefin compounds include olefins such as diisobutylene, isobutylene, Linealene, ethylene, and propylene; and conjugated diene compounds include isoprene, butadiene, and the like.

Regarding the above-mentioned cross-linkable monomers, for example, as vinyl compounds, vinyl-based monomers such as divinylbenzene, 1,4-divinyloxybutane, and divinylsulfone; as (meth)acrylic acid Compounds include tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri( Meth)acrylate, Di-Neopentylthritol Hexa(Meth)acrylate, Di-Neopentylthritol Penta(Meth)acrylate, Glycerin Tri(meth)acrylate, Glycerol Di(meth)acrylate, (Poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, (poly)butylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate Polyfunctional (meth)acrylates such as meth)acrylates; examples of allyl compounds include triallyl cyanurate, triallyl trimellitate, and diallyl phthalate Esters, diallyl acrylamide, diallyl ether; Examples of polysiloxane compounds include tetramethoxysilane, tetraethoxysilane, triethylsilane, tertiary butyldimethylsilane, Methyltrimethoxysilane, Methyltriethoxysilane, Ethyltrimethoxysilane, Ethyltriethoxysilane, Isopropyltrimethoxysilane, Isobutyltrimethoxysilane, Cyclohexyltrimethoxy Nylsilane, n-hexyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane Silane, Diisopropyldimethoxysilane, Trimethoxysilylstyrene, γ-(Meth)acryloxypropyltrimethoxysilane, 1,3-Divinyltetramethyldisiloxane Alkoxysilanes such as alkane, methylphenyldimethoxysilane, and diphenyldimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinyl Silane, Dimethoxyethylvinylsilane, Diethoxymethyldivinylsilane, Diethoxyethylvinylsilane, Ethylmethyldivinylsilane, Methylvinyldimethoxy Silane, ethylvinyldimethoxysilane, methylvinyldiethoxysilane, ethylvinyldiethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropane Dimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyl Alkoxysilanes containing polymerizable double bonds such as propyltriethoxysilane and 3-acryloxypropyltrimethoxysilane, cyclic siloxanes such as decamethylcyclopentasiloxane, single-terminal modification Modified (reactive) silicone oil, (meth)acrylic acid, maleic acid, maleic anhydride, etc. Carboxyl-containing monomers, etc.

The cross-linking and non-cross-linking monomers are not limited to the monomers listed above, and may be other polymerizable monomers, such as known polymerizable monomers.

The above-mentioned resin particles are obtained by polymerizing the above-mentioned polymerizable monomer having an ethylenically unsaturated group by a known method. As this method, for example, a method of performing suspension polymerization in the presence of a radical polymerization initiator; and a method of polymerizing by swelling the monomer and the radical polymerization initiator together using non-crosslinked seed particles (The so-called seed polymerization method) and so on. The conditions of these polymerization methods are not particularly limited, and known conditions can be widely applied.

When the above-mentioned substrate particles are inorganic particles or organic-inorganic hybrid particles other than metal particles, silica, carbon black, and the like are exemplified as inorganic substances as materials of the substrate particles. It is preferred that the inorganic substance is not a metal. The particles formed using the above-mentioned silica are not particularly limited, for example, cross-linked polymer particles are formed by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups, and then, if necessary, Particles obtained by calcination. Examples of the above-mentioned organic-inorganic hybrid particles include organic-inorganic hybrid particles formed from a crosslinked alkoxy silicon-based polymer and an acrylic resin.

As another example of the material of the above-mentioned substrate particle, a polyrotaxane-containing resin is mentioned. Polyrotaxane refers to a structure in which chain-like polymers penetrate the openings of ring-like molecules. The type of polyrotaxane is not particularly limited, and known polyrotaxanes are listed, for example.

When the material constituting the substrate particles is a polyrotaxane-containing resin, the polyrotaxane is preferably a crosslinked body. Specifically, a structure in which a cyclic molecule in a polyrotaxane is cross-linked with a cyclic molecule in another polyrotaxane via a polymer chain is preferable. As long as it is such a crosslinked polyrotaxane, since the flexibility of the substrate particles becomes high, it is easy to exert a stress relaxation effect, thereby making it easy to suppress the occurrence of cracks and warpage of the bonded structure. The type of polyrotaxane as such a crosslinked body is not particularly limited, and examples thereof include known crosslinked polyrotaxanes.

The above polyrotaxane can be produced, for example, by a known method. For example, a polyrotaxane having a crosslinked structure is produced by reacting a polyrotaxane having a cyclic molecule having a polymerizable functional group with a mixture of polymerizable monomers. This reaction can be performed by a known method, for example.

The type of polyrotaxane having a cyclic molecule having a polymerizable functional group is not particularly limited. Specific examples include "SeRM (registered trademark) Super Polymer SM3405P", "SeRM (registered trademark) Key Mixture SM3400C", "SeRM (registered trademark) Super Polymer SA3405P", " SeRM(registered trademark) Super Polymer SA2405P", "SeRM(registered trademark) Key Mixture SA3400C", "SeRM(registered trademark) Key Mixture SA2400C", "SeRM(registered trademark) Super Polymer SA3405P", "SeRM(registered trademark) Super Polymer Polymer SA2405P", etc.

The average particle diameter of the substrate particles is not particularly limited, and may be set to less than 1/2 of the thickness of the adhesive layer in the bonded structure, for example. When the average particle size of the substrate particles is the above-mentioned particle size, it is less likely to cause cracks and warpage of the adhesive layer, and it is also less likely to cause a decrease in the adhesive force of the adhesive layer.

In addition, the average particle diameter of the substrate particles is preferably not less than 0.1 μm and not more than 55 μm. In this case, it is less likely to cause cracks and warpage of the bonded structure during the thermal cycle, and it is less likely to cause a decrease in the adhesive force of the adhesive layer after the thermal cycle test. The average particle diameter of the substrate particles is preferably at least 0.5 μm, more preferably at least 1 μm, and is preferably at most 40 μm, more preferably at most 10 μm, and most preferably at most 6 μm.

In addition, the average particle diameter of a base material particle can also be made the same as the thickness of an adhesive layer. In this case, the metal atom-containing particles can also function as the gap control particles 30 explained in FIG. 1 .

The average particle diameter of the above-mentioned substrate particles means the diameter when the shape is spherical, and means the average value of the maximum diameter and the minimum diameter when the shape is other than spherical. In addition, the average particle diameter of the substrate particles means the average value obtained by observing the substrate particles with a scanning electron microscope and measuring the particle diameters of 50 randomly selected substrate particles with a caliper. In addition, the average particle diameter in the case where a base material particle is covered with another material (for example, a metal part) as mentioned above also includes this coating layer.

The coefficient of variation (CV value) of the particle diameter of the substrate particle is, for example, 50% or less. The above-mentioned coefficient of variation (CV value) is represented by the following formula.

CV value (%)=(ρ/Dn)×100

ρ: standard deviation of particle size

Dn: average particle diameter

From the viewpoint of further suppressing the occurrence of cracks or peeling of the bonded structure, the CV value of the particle diameter of the substrate particles is preferably 40% or less, more preferably 30% or less. The lower limit of the CV value of the particle diameter of the substrate particles is not particularly limited. The above-mentioned CV value may be 0% or more, may be 5% or more, may be 7% or more, and may be 10% or more.

The hardness of the substrate particles is not particularly limited, and is, for example, not less than 10 N/mm ² and not more than 3000 N/mm ² in terms of a 10% K value. From the viewpoint of further suppressing the occurrence of cracks and warpage of the bonded structure, the 10%K value is preferably at least 100N/ ^mm2 , more preferably at least 1000N/ ^mm2 , and more preferably at most 2500N/ ^mm2 , preferably below 2000N/mm ² .

The so-called 10% K value here refers to the compressive elastic modulus when the substrate particles are compressed by 10%. Measurements can be made as follows. First, using a micro-compression tester, the substrate particles were compressed under the condition of applying a load of a maximum test load of 20 mN for 60 seconds at 25° C. using a smooth indenter end surface of a cylinder (50 μm in diameter, manufactured by Diamond). Measure the load value (N) and compression displacement (mm) at this time. From the measured values obtained, the above-mentioned compressive modulus of elasticity can be obtained from the following formula.

10% K value (N/mm ² )=(3/2 ^1/2 ). F． S ^-3/2 . R ^-1/2

F: The load value when the particle undergoes 10% compression deformation (N)

S: Compression displacement of particles when 10% compression deformation occurs (mm)

R: radius of particle (mm)

As said micro compression tester, "Fischer Scope H-100" etc. by Fischer company can be used, for example. In addition, in the case of obtaining the 30% K value, it can also be calculated by obtaining the above-mentioned parameters when the particles are compressed and deformed by 30%.

The substrate particles preferably have 100 or less aggregated particles per one million particles. The above-mentioned aggregated particles are particles in which one particle is connected to at least one other particle. For example, when 1 million substrate particles include 3 aggregated particles of 3 particles (aggregate of 3 particles), the number of aggregated particles per 1 million substrate particles is 9 . As a method of measuring the above-mentioned aggregated particles, a method of counting the aggregated particles using a microscope with a magnification set so that about 50,000 particles are observed in one field of view, and measuring the total of aggregated particles in 20 fields of view, etc. can be mentioned.

The substrate particles preferably have a thermal decomposition temperature of 200°C or higher. In this case, it is easy to suppress the thermal decomposition of the substrate particles when forming the adhesive layer of the bonded structure as described below. The thermal decomposition temperature of the substrate particles is preferably at least 220°C, more preferably at least 250°C, and still more preferably at least 300°C. In addition, when the substrate particle has the coating layer described below, the temperature at which thermal decomposition occurs first in the substrate particle and the coating layer is defined as the thermal decomposition temperature of the substrate particle.

The metal part may be arranged on the surface of the substrate particle. For example, a metal part exists so that the surface of a base material particle may be covered.

The metal part is formed of a material containing metal. Examples of such metals include gold, silver, tin, copper, copper, germanium, indium, palladium, tellurium, thallium, bismuth, zinc, arsenic, selenium, iron, lead, ruthenium, aluminum, cobalt, titanium, antimony, Cadmium, silicon, nickel, chromium, platinum, rhodium, etc. The metal part may be only any one of these respective metals, or may contain two or more kinds. In addition, the metal part may be an alloy of two or more metals among the metals listed as examples above. With respect to the total mass of the metal portion, the metal contains at least 50% by mass, preferably at least 80% by mass, more preferably at least 90% by mass, and most preferably at least 99% by mass. In addition, the metal portion may be formed only of metal.

Regarding the metal portion, the total amount of nickel, chromium, platinum, and rhodium is preferably 30% by mass or less relative to the total mass of the metal portion.

When the total amount of the above-mentioned nickel, chromium, platinum and rhodium is within the above-mentioned range with respect to the total mass of the above-mentioned metal part, the metal becomes easy to diffuse when the sintered body, especially when the particles constituting the sintered body are silver, As a result, the metal atom-containing particles come into contact with the sintered body more easily.

The total amount of nickel, chromium, platinum, and rhodium is preferably at most 25% by mass, more preferably at most 20% by mass, further preferably at most 10% by mass, and most preferably 0% by mass, based on the total mass of the metal part. . Regarding the metal portion, when the total amount of nickel, chromium, platinum, and rhodium is within the ranges described above with respect to the total mass of the metal portion, particles containing metal atoms are particularly likely to come into contact with the sintered body.

The metal part is preferably made of an alloy containing at least one metal element selected from gold, silver, tin, copper, germanium, indium, palladium, tellurium, thallium, bismuth, zinc, arsenic, selenium, and these metal elements. One or more of the groups formed. In this case, the metal atom-containing particles and the sintered body of the metal particles can be more easily contacted, and the occurrence of warpage and cracks in the bonded structure can be further suppressed.

The optimal metal part contains a thermal conductivity of 200W/m. Metals above K. When such a metal is contained, it is easy to further suppress the occurrence of warpage and cracks in the bonded structure, and it becomes possible to improve heat dissipation. As such a metal, one type selected from the group which consists of gold, silver, and copper is mentioned, for example.

The metal portion may be formed of one layer or may be formed of multiple layers.

The metal portion is preferably a so-called multilayer structure formed of multiple layers. The metal contained in each layer may also be different. For example, the metal part may be formed in a double layer structure.

FIG. 2 schematically shows the appearance of metal atom-containing particles having a metal portion formed in a double-layer structure. In addition, in order to show a partial cross-sectional structure of a particle containing a metal atom, the part enclosed by the dotted line part is broken and shown in FIG. 2.

The metal atom-containing particle 10 of the form shown in FIG. 2 includes a substrate particle 11 and a metal part 12 . The metal part 12 is arranged so as to cover the surface of the substrate particle 11 . In addition, the metal part 12 is formed in a double-layer structure by the first metal part 12a and the second metal part 12b, the first metal part 12a is arranged on the inner side, and the second metal part 12b is arranged on the outer side. That is, the first metal part 12a is in contact with the surface of the substrate particle 11, and the second metal part 12b exists so as to cover the surface of the first metal part 12a.

When the metal atom-containing particle 10 has a metal portion with a double-layer structure as shown in FIG. One or more of them. As a specific example, the first metal part 12a contains copper, and the second metal part 12b contains silver. By making the second metal part 12b silver, the contact area with the metal sintered body becomes larger easily, and it becomes easy to contact with the metal sintered body. Moreover, when the 1st metal part 12a is copper, since the usage-amount of the silver of the 2nd metal part 12b can be reduced, it becomes economically advantageous.

In the metal atom-containing particles used in the bonded structure of the present embodiment, the thickness of the metal portion is preferably at least 0.5 nm, more preferably at least 10 nm, and preferably at most 10 μm, more preferably at most 1 μm, and further Preferably it is 500 nm or less, especially preferably 300 nm or less. If the thickness of the metal part is more than the above-mentioned lower limit and below the above-mentioned upper limit, the particles containing metal atoms become more likely to be uniformly dispersed in the sintered body of metal particles, and in addition, it becomes easier to contact the sintered body (that is, the metal atom-containing The contact area between the particles and the sintered body becomes larger), so the occurrence of warping and cracking of the bonded structure can be further suppressed. When the above-mentioned thickness of the metal part has multiple layers, it refers to the total thickness of each layer, that is, the thickness of the entire metal part.

In the metal atom-containing particles used in the bonded structure of the present embodiment, the method of forming the metal part on the surface of the substrate particle is not particularly limited. As a method of forming the metal portion, for example, a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and coating a paste containing metal powder or metal powder and a binder A method of distributing on the surface of substrate particles, etc. From the viewpoint of the convenience of forming the metal part, the method by electroless plating is preferable. Examples of the above-mentioned method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering.

When the metal part has a multilayer structure, the metal part can also be formed by the same method. For example, the metal part of the first layer can be formed on the surface of the substrate particle by using the above-mentioned method of forming the metal part, and the next layer can be sequentially formed on the surface of the first layer, thereby forming a multilayer structure. metal department.

In addition, the form of the above-mentioned metal part is just an example, and the particle containing a metal atom may have the metal part of the form other than the above.

The above metal part may also have a plurality of protrusions on the outer surface.

Fig. 3 schematically shows the appearance of a metal atom-containing particle having a metal portion having a plurality of protrusions on the outer surface. In addition, in order to show a partial cross-sectional structure of particles containing metal atoms, the portion surrounded by the dotted line is broken and shown in FIG. 3 .

The metal atom-containing particle 10 of the form shown in FIG. 3 includes a substrate particle 11 and a metal portion 12 . The metal part 12 is arranged so as to cover the surface of the substrate particle 11 . In addition, the metal part 12 is formed into a double-layer structure by the first metal part 12a and the second metal part 12b, the first metal part 12a is arranged inside, and the second metal part 12b is arranged outside. That is, the first metal part 12a is in contact with the surface of the substrate particle 11, and the second metal part 12b exists so as to cover the surface of the first metal part 12a. The configuration of the metal portion 12 formed of a double-layer structure can be the same as that of the metal atom-containing particle 10 in the form of FIG. 2 described above.

A plurality of protrusions 13 are formed on the outer surface of the metal portion 12 . The protrusion 13 is formed so that the base may be the bottom surface, and the protrusion 13 may protrude from the base to the surface side. Due to the presence of such a plurality of protrusions 13, the metal atom-containing particles and the sintered body of the metal particles become more easily contacted, and as a result, the occurrence of warpage and the occurrence of cracks in the bonded structure can be easily suppressed. In addition, the position where the above-mentioned base portion is formed is on the surface of the metal portion 12 .

It does not specifically limit as a method of forming the said protrusion, For example, a well-known method can be used. Specifically, a method of forming a metal portion by electroless plating after attaching a core substance to the surface of a substrate particle; and a method of forming a metal portion by electroless plating on the surface of a substrate particle , a method of attaching a core material thereon, and then forming a metal part by electroless plating, etc. Furthermore, as another method of forming the above-mentioned protrusions, there may be mentioned: after forming the first metal part on the surface of the substrate particle, disposing a core substance on the first metal part, and then forming the second metal part; A method of adding a core substance in the middle of forming a metal part on the surface of a substrate particle, etc.

As a method for attaching the core substance to the surface of the substrate particle, for example, adding the core substance to the dispersion liquid of the substrate particle, for example, by van der Waals force, the core substance is accumulated and attached to the surface of the substrate particle method; and a method of adding a core substance to a container containing substrate particles, and attaching the core substance to the surface of the substrate particles by mechanical action caused by rotation of the container, etc. Among them, the method of accumulating and adhering the core substance on the surface of the substrate particle in the dispersion liquid is preferable from the viewpoint of easy control of the amount of the core substance to be adhered. If the core material is embedded in the metal part, protrusions can be easily formed on the outer surface of the metal part.

As a material of the said core substance, a conductive substance and a nonconductive substance are mentioned. Examples of the conductive substance include conductive nonmetals such as metals, metal oxides, and graphite, and conductive polymers. As said conductive polymer, polyacetylene etc. are mentioned. Silica, alumina, zirconia, etc. are mentioned as said nonconductive substance. Among them, a metal is preferable from the viewpoint of making it easier to contact the sintered body. The aforementioned core substance is preferably metal particles. As a metal in this case, the above-mentioned various metal which can comprise a metal part can be illustrated. It is more preferable to set it as the same kind as the metal which comprises the outermost layer of a metal part. Therefore, it is preferable that the metal constituting the protrusion contains at least one kind selected from the group consisting of gold, silver and copper.

The shape of the above-mentioned core substance is not particularly limited. The shape of the core substance is preferably block. Examples of the core substance include granular lumps, aggregated lumps in which many fine particles aggregate, amorphous lumps, and the like.

The average diameter (average particle diameter) of the above-mentioned core material is preferably 0.001 μm or more, more preferably 0.05 μm or more, and preferably 0.9 μm or less, more preferably 0.2 μm or less. The average diameter (average particle diameter) of the above-mentioned core substance represents a number average diameter (number average particle diameter). The average diameter of the core substance was obtained by observing arbitrary 50 core substances with an electron microscope or an optical microscope, and calculating the average value. For particles containing metal atoms, in the case of measuring the average diameter of the core substance, for example, the average diameter of the core substance can be measured in the following manner. The particles were added to "Technovit 4000" manufactured by Kulzer Corporation so that the content of metal atom-containing particles became 30% by weight, and dispersed to prepare an embedding resin for metal atom-containing particle inspection. A cross section of the metal atom-containing particle was cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the metal atom-containing particle dispersed in the embedding resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification was set to 50,000 times, 20 metal atom-containing particles were randomly selected, and 20 protrusions of each metal atom-containing particle were observed. Measure the diameter of the core substance in the obtained metal atom-containing particles, calculate the arithmetic mean value, and set it as the average diameter of the core substance.

The shape of the protrusion is not particularly limited, and for example, it may be formed in a spherical or elliptical cross section, or may be formed in a needle shape that becomes sharper toward the tip. The shape of such protrusions can be controlled, for example, according to the material of the core substance and the like.

The average height of the protrusions can be set to not less than 1 nm and not more than 1000 nm, preferably not less than 5 nm, more preferably not less than 50 nm, and preferably not more than 900 nm, more preferably not more than 500 nm. The particle containing a metal atom becomes easy to contact a sintered body as the average height of the said protrusion is more than the said minimum and below the said upper limit.

The average height of the protrusions can be measured, for example, as follows. The particles were added to "Technovit 4000" manufactured by Kulzer Corporation so that the content of metal atom-containing particles became 30% by weight, and dispersed to prepare an embedding resin for metal atom-containing particle inspection. A cross section of the metal atom-containing particle was cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the metal atom-containing particle dispersed in the embedding resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification was set to 50,000 times, 20 metal atom-containing particles were randomly selected, and 50 protrusions of each metal atom-containing particle were observed. The height from the base as the bottom surface of the protrusion to the top of the protrusion was defined as the height of the protrusion, and the arithmetic mean thereof was calculated to be the average height of the protrusion.

The average diameter of the base of the protrusions can be set to be 3 nm or more and 5000 nm or less, preferably 50 nm or more, more preferably 80 nm or more, and preferably 1000 nm or less, more preferably 500 nm or less. Here, the average diameter of the base refers to a value obtained by observing randomly selected ones by FE-SEM observation using the embedded resin in the same order as the above-mentioned measurement method of the average height of the protrusions. For the protrusions of 20 particles containing metal atoms, measure the distance between the two ends of each base, and calculate the arithmetic mean.

In 100% of the total surface area of the outer surface of the metal part, the above-mentioned protrusions may account for 30% or more. In this case, the metal atom-containing particles come into contact with the sintered body more easily. The area occupied by the protrusions on the outer surface of the metal part can be measured in the following manner, for example. First, a field emission scanning electron microscope (FE-SEM) is used to take an orthographic plan view of particles containing metal atoms. The 6000-fold photograph taken by FE-SEM was analyzed by commercially available image analysis software. After performing image processing such as flattening, the area of the protrusions (area in plan view) is obtained, and the ratio of the area of the protrusions to the area of the metal atom-containing particles is defined as the occupied area of the protrusions. For 20 metal atom-containing particles, the area occupied by the protrusions on the outer surface of the metal portion was determined.

As another form of metal atom-containing particles, a substrate particle having a concave portion and a metal portion arranged on the surface of the substrate particle may be provided. In the metal atom-containing particle of this form, the metal portion may also be formed in the concave portion. Hereinafter, specific examples will be given and described.

4 shows an example of a metal atom-containing particle 10 having a substrate particle 11 having a concave portion 14 and a metal portion 12 arranged on the surface of the substrate particle 11, and schematically shows the appearance of the metal atom-containing particle 10. In addition, in order to show a partial cross-sectional structure of the particle 10 containing a metal atom, the part enclosed by the dotted line part is broken and shown in FIG.

In the metal atom-containing particle 10 of the form shown in FIG. 4 , a plurality of recesses 14 are formed on the surface of the substrate particle 11 . The metal part 12 is arranged so as to cover the surface of the substrate particle 11 . In this form, the metal part 12 is formed into a double-layer structure by the first metal part 12a and the second metal part 12b, the first metal part 12a is arranged inside, and the second metal part 12b is arranged outside. That is, the first metal part 12a is in contact with the surface of the substrate particle 11, and the second metal part 12b exists so as to cover the surface of the first metal part 12a. The configuration of the metal part 12 forming the double-layer structure can be set to the same configuration as the metal atom-containing particle 10 of the form shown in FIG. 2 described above.

The metal portion 12 is also formed on the surface of the concave portion 14 . In the form of FIG. 4 , the first metal portion 12 a is formed in the concave portion 14 .

In the metal atom-containing particle in which the metal portion is formed on the surface of the substrate particle having a plurality of recesses as described above, the sintered body of the metal atom-containing particle and the metal particle becomes more likely to be in contact, and the connection structure is made The effect of stress relaxation becomes high. That is, by providing the metal atom-containing particles with recesses, the metal atom-containing particles are more likely to follow deformation. As a result, even if stress is applied to the bonded structure, it is further less likely to cause warpage and cracks.

There are no particular limitations on the method of producing substrate particles having concave portions. For example, the substrate particles may be post-processed to form recessed portions on the substrate particles.

The method of forming the concave portion by the post-processing is not particularly limited, and known methods can be used, for example. Specifically, examples include: a method of etching the surface of substrate particles; a method of plasma treatment, ozone treatment, and heat treatment in an oxygen atmosphere; a method of humidification treatment; a method of heat treatment in a vacuum ; heat treatment method under pressurized and humidified conditions; wet treatment method using oxidizing agent; physical treatment method using ball mill, etc.

The average depth of the concave portion is not particularly limited. For example, the average depth of the concave portion can be set to 0.1% or more and 80% or less of the average radius of the substrate particles. In addition, the depth of the concave portion here means the distance from the surface of the spherical substrate particle to the bottommost point of the concave portion when the substrate particle having the concave portion is regarded as a spherical shape. Specifically, in the same order as the method of measuring the average height of the above-mentioned protrusions, the protrusions of 20 randomly selected metal atom-containing particles are respectively observed by FE-SEM observation using the embedded resin, and each concave portion is calculated. The value obtained from the arithmetic mean of the depth.

Fig. 5 shows a further modified example of the metal atom-containing particle 10, schematically showing the appearance of the metal atom-containing particle. In addition, in order to show a partial cross-sectional structure of a particle containing a metal atom, the part surrounded by the dotted line part is broken and shown in FIG. 5 .

Specifically, the metal atom-containing particle 10 of FIG. 5 has a plurality of substrate particles 11 having recesses 14 and metal portions 12 arranged on the surface of the substrate particle 11, and a plurality of protrusions are formed on the outer surface of the metal portion 12. 13. The metal part 12 is formed in a double-layer structure by using the first metal part 12a and the second metal part 12b. That is, the metal atom-containing particle 10 of the form shown in FIG. 5 has both the characteristics of the metal atom-containing particle 10 shown in FIG. 3 and FIG. 4 .

In the case of the metal atom-containing particle 10 of the form shown in FIG. With each concave portion 14, the particles containing metal atoms become easy to follow the deformation. Therefore, especially in the bonded structure including the metal atom-containing particles 10 of the form shown in FIG. 5 , occurrence of warpage and cracks can be easily suppressed.

The metal atom-containing particle 10 of the form in FIG. 5 can be obtained by the following method, that is, in the metal atom-containing particle 10 of the form of FIG. The method is the same except for particle 11.

Regardless of the form of the metal atom-containing particle 10, the hardness of the metal atom-containing particle 10 is not particularly limited, for example, it is 10 N/mm ² or more and 6000 N/mm ² or less in terms of 10% K value. From the viewpoint of further suppressing the occurrence of cracks and warping of the bonded structure, the 10% K value of the metal atom-containing particles 10 is preferably 100 N/mm ² or more, more preferably 1000 N/mm ² or more, and Preferably it is 5500N/ ^mm2 or less, especially preferably 5000N/ ^mm2 or less.

The metal contained in the sintered body of metal particles is not particularly limited. For example, the metal contained in the sintered body of metal particles preferably contains a metal element selected from gold, silver, tin, copper, germanium, indium, palladium, cerium, thallium, bismuth, zinc, arsenic, selenium, and One or more of the group consisting of alloys of at least one metal element. In this case, the metal atom-containing particles and the sintered body of the metal particles can be more easily contacted, and the occurrence of warpage and cracks in the bonded structure can be further suppressed. The metal contained in the sintered body of metal particles preferably contains one or more metals selected from the group consisting of gold, silver and copper. In addition, the sintered body of metal particles may be formed of only metal.

In the adhesive layer, particles containing metal atoms are embedded in a sintered body of metal particles. In particular, particles containing metal atoms exist in such a manner that a part or the whole of the surface is in contact with the sintered body of metal particles.

Specifically, the particles containing metal atoms are in contact with the sintered system through chemical bonding. The type of such a chemical bond is not limited, and a metal bond is exemplified. In particular, it is preferable that the metal contained in the metal portion or protrusion present on the surface of the metal atom-containing particle forms a solid solution with the metal contained in the sintered body. In this case, since the metal atom-containing particles are more firmly in contact with the sintered body, even if stress is applied to the bonded structure, it becomes more difficult to cause warpage and cracks.

Part of the surface of the metal atom-containing particle may be brought into contact with the sintered body, or the entire surface of the metal atom-containing particle may be brought into contact with the sintered body.

Specifically, in the bonded structure of the present embodiment, 5% or more of the peripheral length of the particles containing metal atoms is in contact with the above-mentioned sintered body in the cross section of the adhesive layer. Thereby, the particles containing metal atoms are in firm contact with the sintered body, and even if stress is applied to the bonded structure, it becomes more difficult to cause warpage and cracks.

From the viewpoint of the surface area of the metal atom-containing particle, it is preferable that 5% or more of the entire surface area of the metal atom-containing particle is in contact with the sintered body.

Fig. 6 schematically shows the cross-sectional structure of the adhesive layer 50 in the bonded structure of this embodiment. The following layer 50 has particles 10 containing metal atoms and a sintered body 20 . Particles 10 containing metal atoms are formed by having at least substrate particles 11 and metal parts 12 .

In FIG. 6( a ), most of the periphery of the metal atom-containing particles 10 (for example, 5% or more of the total length of the periphery) is in contact with the sintered body 20 . With this form, even if stress is applied to the bonded structure, it is more difficult to cause warpage and cracks.

On the other hand, in Fig. 6 (b), only a part of the periphery of the particles 10 containing metal atoms (for example, less than 5% of the total length of the periphery) is in contact with the sintered body 20, and near the surface of the particles 10 containing metal atoms A large number of voids 9 are formed. In this form, when stress is applied to the bonded structure, the metal atom-containing particles 10 are deformed, and a force (restoration force) that restores the metal atom-containing particles 10 to their original shape acts. When returning to the original shape in this way, if a large number of voids 9 are formed and there are spaces, the restorability of the particles becomes high, so due to the restorative force, it becomes easy to cause cracks in the adhesive layer or other constituent members constituting the bonded structure, or Warpage occurs.

In the section of the adhesive layer, it is preferable that more than 10% of the peripheral length of the particles containing metal atoms are in contact with the sintered body, more preferably more than 50% are in contact with the sintered body, and most preferably more than 90% are in contact with the sintered body.

In the cross section of the adhesive layer, the contact between the periphery of the metal atom-containing particles and the sintered body can be confirmed, for example, by observing the cross section of the adhesive layer with a transmission electron microscope FE-TEM. The contact between the metal atom-containing particles and the sintered body can be confirmed, for example, as follows.

First, the particles were added to the below-mentioned sintering material so that the content of the metal atom-containing particles became 5% by weight, and dispersed to prepare a sintering paste (composition for connection). In addition, a power semiconductor element having nickel/gold plating on the connection surface was prepared as a first connection object member. An aluminum nitride substrate with copper plating on the connection surface was prepared as a second connection object member. The said paste for sintering was apply|coated on the 2nd connection object member so that thickness may become about 70 micrometers, and the paste layer for sintering was formed. Then, the first member to be connected is laminated on the sintering paste layer to obtain a laminate.

Then, the obtained laminate was preheated on a hot plate at 130°C for 60 seconds, and then a pressure of 10 MPa was applied to the laminate and heated at 300°C for 3 minutes, thereby making the above-mentioned content of the sintering paste The particles of the metal atoms are sintered to form a connection portion including the sintered product and the metal atom-containing particles, and the sintered product is used to join the first and second members to be connected to obtain a bonded structure.

Next, the obtained bonded structure was put into "Technovit 4000" manufactured by Kulzer Co., Ltd. and hardened to prepare an embedding resin for inspection of the bonded structure. Mechanical polishing was performed so as to pass through the vicinity of the center of the bonded structure embedded in the resin for inspection, and a cross section of particles containing metal atoms was cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.).

Then, by using a transmission electron microscope FE-TEM ("JEM-2010FEF" manufactured by JEOL Ltd.), the contact portion between the particles containing metal atoms and the sintered body was analyzed using an energy dispersive X-ray analyzer (EDS). Linear analysis or element distribution analysis to observe the diffusion state of metal components.

By observing the state of diffusion of the above-mentioned metal, it was possible to confirm that the periphery of the particles containing metal atoms was in contact with the sintered body.

In addition, by analyzing the distribution of the diffusion state of the above-mentioned metal components, the contact ratio between the periphery of the particles containing metal atoms and the sintered body can be calculated by automatic calculation, etc., and the contact ratio can also be quantified by this method.

The sintered body of metal particles can be formed, for example, by sintering a sintering material containing metal particles at a specific temperature.

The metal particles contained in the material for sintering may be particles of a simple metal or particles of a metal compound. A metal compound is a compound containing a metal atom and atoms other than the metal atom.

Specific examples of the metal compound include metal oxides, metal carbonates, metal carboxylates, and metal complexes. The metal compound is preferably a metal oxide. For example, the above-mentioned metal oxides are sintered after being turned into metal particles by heating at the time of connection in the presence of a reducing agent. The aforementioned metal oxide is a precursor of metal particles. As the carboxylate particles of metal, acetate particles of metal and the like are exemplified.

The metal contained in the metal particle and the metal compound preferably includes at least 1 element selected from the group consisting of gold, silver, tin, copper, germanium, indium, palladium, tellurium, thallium, bismuth, zinc, arsenic, selenium, and elements containing these metals. One or more of the group consisting of alloys of metal elements. In this case, the metal atom-containing particles and the sintered body of the metal particles can be more easily contacted, and the occurrence of warpage and cracks in the bonded structure can be further suppressed. The metal contained in the sintered body of metal particles preferably contains at least one type selected from the group consisting of gold, silver, and copper. In the case of using silver particles and silver oxide particles, the sintered body becomes more likely to be firmly in contact with the metal atom-containing particles. Examples of silver oxide include Ag ₂ O and AgO.

The average particle diameter of the metal particles is preferably not less than 10 nm and not more than 10 μm. In addition, from the viewpoint of improving the connection strength of the members to be connected, it is preferable to have two or more types of metal particles with different average particle diameters. When there are two or more kinds of metal particles having different average particle diameters, the average particle diameter of the metal particles having a smaller average particle diameter is preferably at least 10 nm and preferably at most 100 nm. The average particle diameter of the metal particles having a relatively large average particle diameter is preferably at least 1 μm and preferably at most 10 μm. It is preferable that the compounding quantity ratio of the metal particle with a small average particle diameter with respect to the metal particle with a large average particle diameter is 1/9 or more and 9 or less. In addition, the above-mentioned average particle diameter was obtained by observing the metal particles with a scanning electron microscope, and calculating the arithmetic mean of the maximum diameters of 50 particles arbitrarily selected from the observed image. .

The metal particles are preferably sintered under heating of less than 400°C. The temperature at which the metal particles are sintered (sintering temperature) is more preferably 350°C or lower, and more preferably 300°C or higher. If the sintering temperature of the metal particles is below the above upper limit or below the above upper limit, the sintering can be efficiently performed, thereby reducing the energy required for sintering and reducing the environmental burden.

When the metal particles are metal oxide particles, it is preferable that a reducing agent is contained in the material for sintering containing the metal particles. Examples of the reducing agent include alcohols (compounds having an alcoholic hydroxyl group), carboxylic acids (compounds having a carboxyl group), amines (compounds having an amino group), and the like. The said reducing agent may use only 1 type, and may use 2 or more types together.

Examples of the above-mentioned alcohols include alkanols. Specific examples of the aforementioned alcohols include, for example, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, Alcohol, Myristyl Alcohol, Pentadecyl Alcohol, Cetyl Alcohol, Heptadecanyl Alcohol, Stearyl Alcohol, Nonadecanyl Alcohol, Eicosanol, etc. In addition, the above-mentioned alcohols are not limited to primary alcohol-type compounds, and secondary alcohol-type compounds, tertiary alcohol-type compounds, alkane diols, and alcohol compounds having a cyclic structure can also be used. Furthermore, as the aforementioned alcohols, compounds having a plurality of alcohol groups such as ethylene glycol and triethylene glycol can also be used. Moreover, compounds, such as citric acid, ascorbic acid, and glucose, can also be used as said alcohols.

As said carboxylic acid, an alkylcarboxylic acid etc. are mentioned. Specific examples of the aforementioned carboxylic acids include butyric acid, pentanoic acid, hexanoic acid, heptanoic acid, caprylic acid, nonanoic acid, capric acid, undecanoic acid, dodecanoic acid, tridecanoic acid, and tetradecanoic acid. , Pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid and eicosanoic acid, etc. In addition, the above-mentioned carboxylic acids are not limited to primary carboxylic acid type compounds, and secondary carboxylic acid type compounds, tertiary carboxylic acid type compounds, dicarboxylic acids, and carboxyl compounds having a ring structure can also be used.

Alkylamine etc. are mentioned as said amines. Specific examples of the aforementioned amines include butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, and tetradecylamine. Amine, Pentadecylamine, Hexadecylamine, Heptadecylamine, Octadecylamine, Nonadecylamine, Icodecylamine, etc. In addition, the above-mentioned amines may have a branched structure. As amines which have a branched structure, 2-ethylhexylamine, 1, 5- dimethylhexylamine, etc. are mentioned. The aforementioned amines are not limited to primary amine compounds, and secondary amine compounds, tertiary amine compounds, and amine compounds having a ring structure can also be used.

The above-mentioned reducing agent can also be an organic substance having an aldehyde group, an ester group, a sulfonyl group, or a ketone group, or an organic substance such as a metal carboxylate. Metal carboxylate salts are also used as precursors of metal particles, and on the other hand, are also used as reducing agents for metal oxide particles in order to contain organic substances.

With respect to 100 parts by weight of metal particles, the content of the above-mentioned reducing agent is preferably at least 1 part by weight, more preferably at least 10 parts by weight, and is preferably at most 1000 parts by weight, more preferably at most 500 parts by weight, and even more preferably at least 1000 parts by weight. 100 parts by weight or less. When content of the said reducing agent is more than the said minimum, the said metal particle can be sintered more densely.

If a reducing agent having a melting point lower than the sintering temperature (joining temperature) of the above-mentioned metal atom-containing particles is used, aggregation will occur during joining, and voids tend to be easily generated in the joining portion. By using the metal carboxylate, since the metal carboxylate is not melted by heating at the time of connection, generation of voids can be suppressed. In addition, a metal compound containing an organic substance other than the metal carboxylate salt can also be used as a reducing agent.

Other materials may be contained in the sintering material containing metal particles. For example, the material for sintering may contain a resin component. When the resin component is contained, the occurrence of cracks in the bonded structure, the occurrence of warpage, and the occurrence of peeling of the adhesive layer are suppressed.

The above-mentioned resin component is not particularly limited. The above-mentioned resin component preferably contains a thermoplastic resin or a curable resin, and more preferably contains a curable resin. As said curable resin, a photocurable resin and a thermosetting resin are mentioned. It is preferable that the said photocurable resin contains a photocurable resin and a photoinitiator. The above-mentioned thermosetting resin preferably contains a thermosetting resin and a thermosetting agent. Examples of the aforementioned resin include known vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, elastomers, and the like. The said resin may use only 1 type, and may use 2 or more types together.

In addition, the sintering material containing metal particles may also contain a dispersion medium. As a dispersion medium, a well-known solvent etc. are mentioned, for example.

The above-mentioned sintering material containing metal particles may also be a commercially available product. Specific examples include "CT2700" manufactured by KYOCERA Chemical, "ASP295," "ASP016," and "ASP043" manufactured by Heraeus, "LOCTITE ABLESTIK SSP2020" manufactured by Henkel, and "H9890-6A" manufactured by Namics. ", "NH-4000", "NH-225D", "NH-3000D" manufactured by Harima Kasei Co., Ltd., "CM-3212" and "CR-3520" manufactured by KAKEN TECH Corporation, "AIconano Silver" manufactured by Nihon Superior Co., Ltd. Plasma ANP-1" and so on.

In the adhesive layer, the content of particles containing metal atoms is preferably at least 0.1% by weight, more preferably at least 1% by weight, and is preferably at most 20% by weight, more preferably at most 10% by weight. When the content of the metal atom-containing particles is more than the above-mentioned lower limit and below the above-mentioned upper limit, the occurrence of cracks and warpage of the bonded structure can be further suppressed.

In the adhesive layer, the content of the metal particles is preferably higher than the content of the above-mentioned particles containing metal atoms, for example, more preferably more than 10% by weight, and more preferably more than 20% by weight.

In the adhesive layer, the content of the metal particles is preferably not less than 70% by weight, more preferably not less than 80% by weight, and preferably not more than 98% by weight, more preferably not more than 95% by weight. When the content of the above-mentioned metal atom-containing particles is more than the above-mentioned lower limit and not more than the above-mentioned upper limit, the occurrence of cracks and warpage of the bonded structure can be further suppressed.

The manufacturing method of the bonded structure of this embodiment is not specifically limited. As an example of the manufacturing method of the above-mentioned bonded structure, it is possible to enumerate: between the first member to be connected and the second member to be connected, a mixture of particles containing metal atoms and the above-mentioned material for sintering is arranged to form a laminate, and A method of heating and pressurizing the laminate, etc. Thereby, the metal particles contained in the laminate are sintered to form an adhesive layer in which particles containing metal atoms are dispersed in the sintered body, and the first member to be connected and the second member to be connected are connected by the adhesive layer.

In particular, in the bonded structure of this embodiment, in the adhesive layer, most of the surface of the particles containing metal atoms is in contact with the sintered body, and the contact is firm, so it is not necessary to perform pressure mounting, and it becomes possible to use the so-called non-contact structure. Install under pressure. Therefore, the connection structure can be advantageously manufactured in steps.

The above-mentioned particles containing metal atoms can increase the contact area with the sintered body of the metal particles in the adhesive layer contained in the bonded structure, so it is suitable as a material for assembling the above-mentioned bonded structure. Therefore, according to the above-mentioned particles containing metal atoms, it is possible to provide a bonded structure that is less likely to cause warpage and cracks.

In addition, the above-mentioned metal atom-containing particles are also suitable as constituent components of the connection composition. Specifically, the composition for connection can be prepared by combining the above-mentioned particles containing metal atoms and the above-mentioned metal particles for sintering.

The above composition for connection contains metal atom-containing particles and metal particles, so it is suitable as a material for assembling a connection structure. Specifically, by applying the composition for connection between the first member to be connected and the second member to be connected, and sintering the metal particles in the composition for connection, an adhesive layer containing particles containing metal atoms can be formed. Floor.

The above composition for connection can be prepared by mixing metal atom-containing particles and metal particles in a specific blending amount. For example, a connection composition can be prepared by mixing the above metal atom-containing particles with a sintering material containing metal particles. The mixing method of metal atom-containing particles and metal particles is not particularly limited, and known mixing methods can be used.

In the connection composition, the mixing ratio of metal atom-containing particles and metal particles is not particularly limited.

For example, the content of metal atom-containing particles is preferably at least 0.1% by weight, more preferably at least 1% by weight, and preferably at most 20% by weight in 100% by weight of the composition for connection except the dispersion medium. , more preferably 10% by weight or less. If the content of the above-mentioned metal atom-containing particles is more than the above-mentioned lower limit and below the above-mentioned upper limit, the above-mentioned metal particles can be sintered more densely, and the contact area of the metal atom-containing particles with the sintered body can be increased.

In addition, the content of the metal particles is preferably at least 70% by weight, more preferably at least 80% by weight, and preferably at most 98% by weight, more preferably at least 98% by weight, in 100% by weight of the composition for connection except the dispersion medium. 95% by weight or less. The said metal particle can be sintered more densely as content of the said metal particle is more than the said minimum and below the said upper limit.

When the above-mentioned connection composition contains a resin component, the content of the above-mentioned resin component is preferably at least 1% by weight, more preferably at least 5% by weight, based on 100% by weight of components other than the dispersion medium in the connection composition. , and preferably less than 20% by weight, more preferably less than 15% by weight. The said metal particle can be sintered more densely as content of the said resin component is more than the said minimum and below the said upper limit.

[Example]

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the aspects of these examples.

(Example 1)

As the substrate particle S1, divinylbenzene copolymer resin particles ("Micropearl SP-203" manufactured by Sekisui Chemical Co., Ltd.) having a particle diameter of 3.0 μm were prepared.

After dispersing 10 parts by weight of the substrate particles S1 in 100 parts by weight of an alkali solution containing a 5% by weight palladium catalyst solution using an ultrasonic disperser, the solution was filtered to take out the substrate particles S1. Next, the substrate particle S1 was added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surface of the substrate particle S1. After sufficiently washing the surface-activated substrate particle S1 with water, it was added to 500 parts by weight of distilled water and dispersed to obtain a suspension (A1).

The suspension (A1) was added to a solution containing 20 g/L of copper sulfate and 30 g/L of ethylenediaminetetraacetic acid to obtain a particle mixture (B1).

In addition, as an electroless copper plating solution, a mixed solution containing 250 g/L of copper sulfate, 150 g/L of ethylenediaminetetraacetic acid, 100 g/L of sodium gluconate, and 50 g/L of formaldehyde was prepared to adjust the pH to 10.5 with ammonia. Copper plating solution (C1).

In addition, as an electroless silver plating solution, a mixed solution containing 30 g/L of silver nitrate, 100 g/L of succinimide, and 20 g/L of formaldehyde was prepared using ammonia water to adjust the pH to 8.0 (D1).

The above-mentioned copper plating solution (C1) was slowly added dropwise to the particle mixture solution (B1) adjusted to a dispersed state at 55°C to perform electroless copper plating. The dropping rate of the copper plating solution (C1) was 30 mL/min, and the dropping time was 30 minutes to perform electroless copper plating. In this manner, a particle mixture (E1) containing particles having a copper metal portion as the first metal portion on the surface of the resin particle was obtained.

Then, the particles were taken out by filtering the particle mixture (E1), and washed with water to obtain particles in which the copper metal part was arranged on the surface of the substrate particle S1. After sufficiently washing the particles with water, it was added to 500 parts by weight of distilled water and dispersed to obtain a particle mixed liquid (F1).

Next, the above-mentioned silver plating solution (D1) was slowly added dropwise to the particle mixture solution (F1) adjusted to a dispersed state at 60°C to perform electroless silver plating. The dropping rate of the silver plating solution (D1) was 10 mL/min, and the dropping time was 30 minutes to perform electroless silver plating. Then, the particles were taken out by filtration, washed with water, and dried to obtain metal atom-containing particles having copper and silver metal parts (thickness of the entire metal part: 0.1 μm) on the surface of the substrate particle S1.

(Example 2)

Substrate particle S1 of Example 1 was prepared. In addition, the same suspension (A2) as the suspension (A1) of Example 1 was prepared.

Next, 1 part by weight of metallic nickel particle slurry ("2020SUS" manufactured by Mitsui Kinzoku Co., Ltd., average particle size: 150nm) was added to the above suspension (A2) over a period of 3 minutes to obtain a substrate containing a core substance attached Suspension of particles S1 (B2).

The suspension (B2) was added to a solution containing 20 g/L of copper sulfate and 30 g/L of ethylenediaminetetraacetic acid to obtain a particle mixture (C2).

Moreover, the same copper plating liquid (D2) as the copper plating liquid (C1) of Example 1 was prepared.

Moreover, the same silver plating solution (E2) as the silver plating solution (D1) of Example 1 was prepared.

The above-mentioned copper plating solution (D2) was slowly added dropwise to the particle mixture solution (C2) adjusted to a dispersed state at 55°C to perform electroless copper plating. The dropping rate of the copper plating solution (D2) was 30 mL/min, and the dropping time was 30 minutes to perform electroless copper plating. In this way, a particle mixture solution (F2) containing particles having a copper metal part disposed on the surface of the resin particle as the first metal part and having a metal part having a protrusion on the surface was obtained.

Then, the particles were taken out by filtering the particle mixture (F2) and washed with water to obtain particles having copper metal parts arranged on the surface of the substrate particle S1 and metal parts having protrusions on the surface. After sufficiently washing the particles with water, it was added to 500 parts by weight of distilled water and dispersed to obtain a particle mixture (G2).

Next, the above-mentioned silver plating solution (E2) was slowly added dropwise to the particle mixture solution (G2) adjusted to a dispersed state at 60°C to perform electroless silver plating. The dropping rate of the silver plating solution (E2) was 10 mL/min, and the dropping time was 30 minutes to perform electroless silver plating. Then, the particles were taken out by filtration, washed with water, and dried to obtain substrate particles S1 with copper and silver metal parts arranged on the surface (thickness of the entire metal part in the part without protrusions: 0.1 μm) and Particles containing metal atoms having a metal portion having a plurality of protrusions on the surface.

(Example 3)

Except having changed the metal nickel particle slurry into the alumina particle slurry (average particle diameter 150nm), it carried out similarly to Example 2, and obtained the particle containing a metal atom.

(Example 4)

Except having changed the metal nickel particle slurry into copper particle slurry (average particle diameter 150nm), it carried out similarly to Example 2, and obtained the particle containing a metal atom.

(Example 5)

The suspension (A1) obtained in Example 1 was added to a solution containing 40 ppm of nickel sulfate, 2 g/L of trisodium citrate, and 10 g/L of ammonia water to obtain a particle mixture (B5).

As the plating solution for forming needle-like protrusions, prepare the following plating solution (C5) for forming needle-like protrusions, which contains copper sulfate 100 g/L, nickel sulfate 10 g/L, sodium hypophosphite 100 g/L, citric acid A mixture of 70g/L trisodium, 10g/L boric acid, and 5mg/L polyethylene glycol 1000 (molecular weight: 1000) as a non-ionic surfactant is adjusted to a pH value of 10.0 with ammonia water. Electroless copper-nickel- Phosphorus plating alloy solution.

In addition, as an electroless silver plating solution, a silver plating solution (D5) in which a mixed solution of 30 g/L of silver nitrate, 100 g/L of succinimide, and 20 g/L of formaldehyde was adjusted to pH 8.0 with aqueous ammonia was prepared.

The above-mentioned plating solution for forming acicular protrusions (C5) was slowly added dropwise to the particle mixture solution (B5) adjusted to a dispersed state at 70°C to form acicular protrusions. The dropping speed of the plating solution (C5) for needle-like protrusion formation is 40mL/min, and the dropping time is 60 minutes, while carrying out electroless copper-nickel-phosphorus alloy plating (acicular protrusion formation and copper-nickel-phosphorus alloy plating step). Then, the particles were taken out by filtration to obtain a particle (E5) having a copper-nickel-phosphorous alloy metal part disposed on the surface of the substrate particle S1 and a metal part having a convex part (precipitation protrusion) on the surface. A suspension (F5) was obtained by adding and dispersing the particles (E5) to 500 parts by weight of distilled water.

Then, the particles are taken out by filtering the suspension (F5) and washed with water to obtain the above-mentioned substrate particle A having a copper-nickel-phosphorus alloy metal portion on the surface and having needle-shaped protrusions on the surface. Particles of the metal part. After the particles were sufficiently washed with water, the particles were added to 500 parts by weight of distilled water and dispersed to obtain a particle mixture (G5).

Next, the above-mentioned silver plating solution (D5) was slowly added dropwise to the particle mixture solution (G5) adjusted to a dispersed state at 60°C to perform electroless silver plating. The dropping speed of the silver plating solution (D5) was 10mL/min, and the dropping time was 30 minutes to perform electroless silver plating. Then, the particles were taken out by filtration, washed with water, and dried to obtain the substrate particle S1 in which the copper-nickel-phosphorous alloy portion and the silver metal portion (the entire metal portion in the portion without protrusions) were arranged on the surface. Thickness: 0.1 μm) and metal atom-containing particles having a metal part having a plurality of needle-like protrusions on the surface.

(Example 6)

The suspension (A1) obtained in Example 1 was added to a solution containing 500 ppm potassium silver cyanide, 10 g/L potassium cyanide, and 10 g/L potassium hydroxide to obtain a particle mixture (B6).

As a plating solution for forming needle-like protrusions, prepare a solution containing potassium silver cyanide 80 g/L, potassium cyanide 10 g/L, polyethylene glycol 1000 (molecular weight: 1000) 20 mg/L, thiourea 50 ppm, and hydrazine monohydrate The mixed solution of 100g/L was adjusted to a silver plating solution (C6) with a pH value of 7.5 by using potassium hydroxide.

The above-mentioned electroless silver plating solution (C6) was slowly added dropwise to the particle mixture solution (B6) adjusted to a dispersed state at 80°C to form acicular protrusions. The dropping rate of the electroless silver plating solution (C6) was 10 mL/min, and the dropping time was 60 minutes to perform electroless silver plating (acicular protrusion formation and silver plating steps). Then, the particles were taken out by filtration, washed with water, and dried to obtain resin particles with a silver metal part arranged on the surface (thickness of the entire metal part in the part without protrusions: 0.1 μm) and having a silver metal part formed on the surface. Particles containing metal atoms in the silver metal part with a plurality of acicular protrusions.

(Example 7)

The suspension (B2) obtained in Example 2 was added to a solution containing 20 g/L of copper sulfate and 30 g/L of ethylenediaminetetraacetic acid to obtain a particle mixture (C7).

In addition, as an electroless copper plating solution, prepare a mixed solution containing 300 g/L copper sulfate, 150 g/L ethylenediaminetetraacetic acid, 120 g/L sodium gluconate, and 70 g/L formaldehyde to adjust the pH to 10.5 with ammonia. Copper plating solution (D7).

The above-mentioned copper plating solution (D7) was slowly added dropwise to the particle mixture solution (C7) adjusted to a dispersed state at 55°C to perform electroless copper plating. The dropping rate of the copper plating solution (D7) was 30 mL/min, and the dropping time was 30 minutes to perform electroless copper plating. Then, the particles were taken out by filtration to obtain a particle mixture (F7) containing particles having a copper metal portion arranged on the surface of the substrate particle A and having a metal portion having a convex portion on the surface.

Then, the particles were taken out by filtration, washed with water, and dried to obtain the substrate particle A on which the copper metal portion (thickness of the entire metal portion in the portion without protrusions: 0.1 μm) was arranged on the surface and which had Particles containing metal atoms having a plurality of protruding metal parts on the surface.

(Embodiment 8)

The suspension (B2) obtained in Example 2 was added to a solution containing 20 g/L of copper sulfate and 30 g/L of ethylenediaminetetraacetic acid to obtain a particle mixture (C8).

In addition, as an electroless copper plating solution, prepare a mixed solution containing 250 g/L copper sulfate, 150 g/L ethylenediaminetetraacetic acid, 100 g/L sodium gluconate, and 50 g/L formaldehyde to adjust the pH value to 10.5 with ammonia. Copper plating solution (D8).

In addition, as an electroless tin plating solution, a mixture containing 20 g/L of tin chloride, 50 g/L of nitrilotriacetic acid, 2 g/L of thiourea, 1 g/L of thiomalic acid, and 7.5 g/L of ethylenediaminetetraacetic acid was prepared. , and a mixture of titanium trichloride 15g/L was adjusted to a tin plating solution (E8) with a pH value of 7.0 using sulfuric acid.

The above-mentioned copper plating solution (D8) was slowly added dropwise to the particle mixture solution (C8) adjusted to a dispersed state at 55°C to perform electroless copper plating. The dropping rate of the copper plating solution (D8) was 30 mL/min, and the dropping time was 30 minutes to perform electroless copper plating. Then, the particles were taken out by filtration to obtain a particle mixture (F8) containing particles having a copper metal portion arranged on the surface of the substrate particle A and having a metal portion having a convex portion on the surface.

Then, the particles were taken out by filtering the particle mixture (F8) and washed with water to obtain particles having a copper metal portion on the surface of the substrate particle A and a metal portion having a convex portion on the surface. After the particles were sufficiently washed with water, the particles were added to 500 parts by weight of distilled water and dispersed to obtain a particle mixture (G8).

Next, the above-mentioned tin plating solution (E8) was slowly added dropwise to the particle mixture solution (G8) adjusted to a dispersed state at 60°C to perform electroless tin plating. The dropping rate of the tin-plating solution (E8) was 10 mL/min, and the dropping time was 30 minutes for electroless tin plating. Then, the particles were taken out by filtration, washed with water, and dried to obtain substrate particles A in which copper and tin metal parts were arranged on the surface (thickness of the entire metal part in the part without protrusions: 0.1 μm) and Particles containing metal atoms having a metal portion having a plurality of protrusions on the surface.

(Example 9)

The suspension (A1) obtained in Example 1 was added to a solution containing 25 g/L of nickel sulfate, 15 ppm of thallium nitrate and 10 ppm of bismuth nitrate to obtain a particle mixture (B9).

In addition, a nickel plating solution (C9) (pH 5.5) containing 100 g/L of nickel sulfate, 40 g/L of sodium hypophosphite, 15 g/L of sodium citrate, 25 ppm of thallium nitrate, and 10 ppm of bismuth nitrate was prepared.

In addition, as the electroless displacement gold plating solution, prepare the gold plating solution (D9) that comprises gold potassium cyanide 10g/L, sodium citrate 20g/L, ethylenediaminetetraacetic acid 3.0g/L and sodium hydroxide 20g/L ( pH 9.0).

The above-mentioned nickel plating solution (C9) was slowly added dropwise to the particle mixture solution (B9) adjusted to a dispersed state at 50°C to perform electroless nickel plating. The dropping rate of the nickel plating solution (C8) was 12.5 mL/min, and the dropping time was 30 minutes to perform electroless nickel plating (nickel plating step). In this way, a particle mixture solution (E9) containing particles having a nickel metal part as the first metal part on the surface of the resin particle was obtained.

Then, the particles were taken out by filtering the particle mixture solution (E9), and washed with water to obtain particles in which the nickel metal part was arranged on the surface of the above-mentioned substrate particle A.

After sufficiently washing the particles with water, it was added to 500 parts by weight of distilled water and dispersed to obtain a particle mixture (F9).

Next, the above gold plating solution (D9) was slowly added dropwise to the particle mixture solution (F9) adjusted to a dispersed state at 60°C to perform electroless displacement gold plating. The dropping rate of the gold-plating solution (D9) was 2 mL/min, and the dropping time was 45 minutes to perform electroless displacement gold-plating. Then, the particles were taken out by filtration, washed with water, and dried to obtain metal atom-containing particles having nickel and gold metal parts (thickness of the entire metal part: 0.05 μm) on the surface of the substrate particle A.

(Example 10)

Substrate particle S1 of Example 1 was prepared. After dispersing 10 parts by weight of substrate particles S1 in 100 parts by weight of an alkali solution containing 10% by weight of potassium permanganate using an ultrasonic disperser, the substrate particles S1 were taken out by filtering the solution. The surface of the substrate particle S1 has recesses.

Next, 10 parts by weight of substrate particles S1 were dispersed in 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the solution was filtered to take out substrate particles S1. Next, the substrate particle S1 was added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surface of the substrate particle S1. After sufficiently washing the surface-activated substrate particle A with water, it was added to 500 parts by weight of distilled water and dispersed to obtain a suspension (A10). In Example 1, except having used suspension (A10) instead of suspension (A1), it carried out similarly to Example 1, and obtained the particle containing a metal atom.

(Example 11)

Substrate particle S1 of Example 1 was prepared. After dispersing 10 parts by weight of the substrate particles S1 in 100 parts by weight of an alkali solution containing 10% by weight of potassium permanganate using an ultrasonic disperser, the solution was filtered to take out the substrate particles S1. The surface of the substrate particle S1 has recesses.

Next, 10 parts by weight of substrate particles S1 were dispersed in 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the solution was filtered to take out substrate particles S1. Next, the substrate particle S1 was added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surface of the substrate particle S1. Suspension (A11) was obtained by adding and dispersing the surface-activated base particle A to 500 parts by weight of distilled water after fully washing with water.

Next, 1 part by weight of metallic nickel particle slurry ("2020SUS" manufactured by Mitsui Kinzoku Co., Ltd., average particle size: 150nm) was added to the above suspension (A11) over a period of 3 minutes to obtain substrate particles containing a core substance Suspension of A (B11).

The suspension (B11) was added to a solution containing 5 g/L of copper sulfate and 8 g/L of ethylenediaminetetraacetic acid to obtain a particle mixed liquid (C11).

In addition, as an electroless copper plating solution, prepare a mixed solution containing 50 g/L copper sulfate, 30 g/L ethylenediaminetetraacetic acid, 20 g/L sodium gluconate, and 10 g/L formaldehyde to adjust the pH value to 10.5 with ammonia. Copper plating solution (D11).

In addition, as an electroless silver plating solution, a mixed solution containing 6 g/L of silver nitrate, 20 g/L of succinimide, and 5 g/L of formaldehyde was prepared to adjust the pH value to 8.0 with ammonia water (E11).

The above-mentioned copper plating solution (D11) was slowly added dropwise to the particle mixture solution (C11) adjusted to a dispersed state at 55°C to perform electroless copper plating. The dropping rate of the copper plating solution (D11) was 5 mL/min, and the dropping time was 40 minutes to perform electroless copper plating. In this way, a particle mixture solution (F11) containing particles having a copper metal part disposed on the surface of a resin particle as a first metal part and having a metal part having a protrusion on the surface was obtained.

Then, the particles were taken out by filtering the particle mixture (F11) and washed with water to obtain the above-mentioned substrate particle S1 having a copper metal part arranged on the surface and a metal part having a protrusion on the surface. After sufficiently washing the particles with water, it was added to 500 parts by weight of distilled water and dispersed to obtain a particle mixture (G11).

Next, the above-mentioned silver plating solution (E11) was slowly added dropwise to the particle mixture solution (G11) adjusted to a dispersed state at 60°C to perform electroless silver plating. The dropping rate of the silver plating solution (E11) was 5 mL/min, and the dropping time was 15 minutes to perform electroless silver plating. Then, the particles were taken out by filtration, washed with water, and dried to obtain substrate particles S1 on which concave portions and copper and silver metal portions were arranged on the surface (thickness of the entire metal portion in the portion without protrusions: 0.01 μm) ) and metal atom-containing particles having a metal part having a plurality of protrusions on the surface.

(Example 12)

Substrate particle S1 of Example 1 was prepared. After dispersing 10 parts by weight of the substrate particles S1 in 100 parts by weight of an acid solution containing 10% by weight of potassium chromate using an ultrasonic disperser, the solution was filtered to take out the substrate particles S1. The surface of the substrate particle S1 has recesses.

Next, 10 parts by weight of substrate particles S1 were dispersed in 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the solution was filtered to take out substrate particles S1. Next, the substrate particle S1 was added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surface of the substrate particle S1. After sufficiently washing the surface-activated substrate particle A with water, it was added to 500 parts by weight of distilled water and dispersed to obtain a suspension (A12).

Next, 1 part by weight of metal nickel particle slurry ("2020SUS" manufactured by Mitsui Kinzoku Co., Ltd., average particle size: 150nm) was added to the suspension (A12) in 3 minutes to obtain a substrate with a core substance attached. Suspension of particles A (B12).

In Example 2, except having used suspension liquid (B12) instead of suspension liquid (B2), it carried out similarly to Example 2, and obtained the particle|grains containing a metal atom.

(Example 13)

1. Preparation of polysiloxane oligomer

1 part by weight of 1,3-divinyltetramethyldisiloxane and 20 parts by weight of a 0.5% by weight aqueous solution of p-toluenesulfonic acid were added to a 100-ml separable flask installed in a warm water bath. After stirring at 40° C. for 1 hour, 0.05 parts by weight of sodium bicarbonate was added. Then, 10 parts by weight of dimethoxymethylphenylsilane, 49 parts by weight of dimethyldimethoxysilane, 0.6 parts by weight of trimethylmethoxysilane, and 3.6 parts by weight of methyltrimethoxysilane were added, and stirred for 1 hour. Then, 1.9 parts by weight of a 10% by weight potassium hydroxide aqueous solution was added, the temperature was raised to 85° C., and the mixture was stirred for 10 hours while decompressing with an aspirator to perform a reaction. After completion of the reaction, return to normal pressure, cool to 40° C., add 0.2 parts by weight of acetic acid, and let stand in a separatory funnel for more than 12 hours. The polysiloxane oligomer was obtained by taking out the lower layer after two layers were separated, and refining it with an evaporator.

2. Production of polysiloxane particle materials (including organic polymers)

A solution in which 0.5 parts by weight of tert-butyl peroxide 2-ethylhexanoate (polymerization initiator, "Perbutyl O" manufactured by NOF Corporation) was dissolved in 30 parts by weight of the obtained polysiloxane oligomer was prepared. Liquid A. In addition, 0.8 parts by weight of a 40% by weight aqueous solution of triethanolamine lauryl sulfate (emulsifier) and 0.8 parts by weight of polyvinyl alcohol (polymerization degree: about 2000, saponification degree: 86.5~89 mol%, Japan Aqueous solution B was prepared with 80 parts by weight of a 5% by weight aqueous solution of "Gohsenol GH-20" manufactured by Synthetic Chemicals Co., Ltd. After adding the above-mentioned solution A to a separable flask installed in a warm water bath, the above-mentioned aqueous solution B was added. Then, emulsification was performed by using a Shirasu porous glass (SPG) membrane (average pore diameter of about 1 μm). Then, the temperature was raised to 85° C., and polymerization was performed for 9 hours. The entire amount of polymerized particles was washed with water by centrifugation, and freeze-dried. After drying, it was pulverized with a ball mill until the aggregates of the particles reached the target ratio (average secondary particle size/average primary particle size) to obtain polysiloxane particles (substrate particle S2) with a particle size of 3.0 μm.

Except having changed the said base material particle S1 into the said base material particle S2, it carried out similarly to Example 2, the metal part was formed, and the particle containing a metal atom was obtained.

(Example 14)

The particle size was obtained by the same method as in Example 13, except that polysiloxane oil with both ends of acrylic acid ("X-22-2445" manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of the polysiloxane oligomer Polysiloxane particles of 3.0 μm (substrate particle S3).

Except having changed the said base material particle S1 into the said base material particle S3, it carried out similarly to Example 2, the metal part was formed, and the particle containing a metal atom was obtained.

(Example 15)

Substrate particle S4 having a particle diameter of 2.0 μm different only from substrate particle S1 was prepared.

Except having changed the said base material particle S1 into the said base material particle S4, it carried out similarly to Example 2, the metal part was formed, and the particle containing a metal atom was obtained.

(Example 16)

Substrate particle S5 having a particle diameter of 10.0 μm different only from substrate particle S1 was prepared.

Except having changed the said base material particle S1 into the said base material particle S5, it carried out similarly to Example 2, the metal part was formed, and the particle containing a metal atom was obtained.

(Example 17)

Substrate particle S6 having a particle diameter of 35.0 μm different only from substrate particle S1 was prepared.

Except having changed the said base material particle S1 into the said base material particle S6, it carried out similarly to Example 1, the metal part was formed, and the particle containing a metal atom was obtained.

(Example 18)

Except having changed the base material particle S1 into the said base material particle S6 of Example 17, it carried out similarly to Example 8, the metal part was formed, and the particle containing a metal atom was obtained.

(Example 19)

酯800g、甲基丙烯酸環己酯100g、及過氧化苯甲醯35g加以混合，使之均勻地溶解，而獲得單體 混合液。製作5kg之聚乙烯醇1重量%水溶液，加入至反應釜中。向其中加入上述單體混合液，藉由攪拌2~4小時，而以單體之液滴成為特定粒徑之方式調整粒徑。然後，於90℃之氮氣環境下進行9小時反應，而獲得粒子。將所獲得之粒子利用熱水多次洗淨後，進行分級操作，而獲得平均粒徑為35.0μm之基材粒子S7。 ethylene glycol dimethacrylate 100g, acrylic acid iso

800 g of esters, 100 g of cyclohexyl methacrylate, and 35 g of benzoyl peroxide were mixed and dissolved uniformly to obtain a monomer mixed liquid. Prepare 5 kg of polyvinyl alcohol 1% by weight aqueous solution and add it to the reaction kettle. The above-mentioned monomer mixture was added thereto and stirred for 2 to 4 hours to adjust the particle size so that the liquid droplets of the monomer became a specific particle size. Then, the reaction was carried out for 9 hours under a nitrogen atmosphere at 90° C. to obtain particles. The obtained particles were washed with hot water several times, and then subjected to a classification operation to obtain substrate particles S7 with an average particle diameter of 35.0 μm.

Except having changed the said base material particle S1 into the said base material particle S7, it carried out similarly to Example 1, the metal part was formed, and the particle containing a metal atom was obtained.

(Example 20)

Except having changed the substrate particle S1 into the substrate particle S7 of Example 19, it carried out similarly to Example 9, the metal part was formed, and the particle containing a metal atom was obtained.

(Example 21)

Substrate particle S8 having a particle diameter of 50.0 μm different from substrate particle S7 in Example 19 was prepared. Except having changed the said base material particle S7 into the said base material particle S8, it carried out similarly to Example 1, the metal part was formed, and the particle containing a metal atom was obtained.

(comparative example 1)

As the substrate particle S1, divinylbenzene copolymer resin particles ("Micropearl SP-203" manufactured by Sekisui Chemical Co., Ltd.) having a particle diameter of 3.0 μm were prepared.

(comparative example 2)

After dispersing 10 parts by weight of the substrate particles S1 in 100 parts by weight of an alkali solution containing a 5% by weight palladium catalyst solution using an ultrasonic disperser, the substrate particles S1 were taken out by filtering the solution. Next, the substrate particle S1 was added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surface of the substrate particle S1. After sufficiently washing the surface-activated substrate particles S1 with water, they were added to 500 parts by weight of distilled water and dispersed to obtain a suspension (a1).

The suspension (a1) was added to a solution containing 50 g/L of nickel sulfate, 30 ppm of thallium nitrate, and 20 ppm of bismuth nitrate to obtain a particle mixture (b1).

In addition, a nickel plating solution (c1) (pH 6.5) containing 200 g/L of nickel sulfate, 85 g/L of sodium hypophosphite, 30 g/L of sodium citrate, 50 ppm of thallium nitrate, and 20 ppm of bismuth nitrate was prepared.

The above-mentioned nickel plating solution (c1) was slowly added dropwise to the particle mixture solution (b1) adjusted to a dispersed state at 50°C to perform electroless nickel plating. The dropping rate of the nickel plating solution (c1) was 25 mL/min, and the dropping time was 60 minutes to perform electroless nickel plating (nickel plating step). Then, the particles are taken out by filtration, washed with water, and dried to obtain metal atom-containing particles (metallic particles) having a nickel-phosphorus metal portion on the surface of the substrate particle S1 and a metal portion having protrusions on the surface. The thickness of the whole part: 0.1μm).

(comparative example 3)

Add 1 g of metallic nickel particle slurry ("2020SUS" manufactured by Mitsui Kinzoku Co., Ltd., average particle size: 150nm) to the same suspension (a1) as in Comparative Example 1 over 3 minutes to obtain a substrate containing a core substance. Suspension (b2) of material particles S1.

The suspension (b2) was added to a solution containing 50 g/L of nickel sulfate, 30 ppm of thallium nitrate, and 20 ppm of bismuth nitrate to obtain a particle mixture (c2).

In addition, a nickel plating solution (d2) (pH 6.5) containing 200 g/L of nickel sulfate, 85 g/L of sodium hypophosphite, 30 g/L of sodium citrate, 50 ppm of thallium nitrate, and 20 ppm of bismuth nitrate was prepared.

The above-mentioned nickel plating solution (d2) was slowly added dropwise to the particle mixture solution (c2) adjusted to a dispersed state at 50°C to perform electroless nickel plating. The dropping rate of the nickel plating solution (d2) was 25 mL/min, and the dropping time was 60 minutes to perform electroless nickel plating (nickel plating step). Then, the particles were taken out by filtration, washed with water, and dried to obtain a metal atom-containing particle (without Thickness of the entire metal portion in the protruding portion: 0.1 μm).

(Evaluation method)

(1) Measurement of the height of the protrusion

The obtained metal atom-containing particles were added to "Technovit 4000" manufactured by Kulzer Co., Ltd. so as to have a content of 30% by weight, and dispersed to prepare an embedding resin for metal atom-containing particle inspection. A cross section of the metal atom-containing particle was cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the metal atom-containing particle dispersed in the embedding resin for inspection.

Then, using a field emission type transmission electron microscope (FE-TEM) ("JEM-ARM200F" manufactured by JEOL Ltd.), set the image magnification to 50,000 times, randomly select 20 particles containing metal atoms, and observe each metal-containing particle. The protrusion of the particle of the atom. Measure the height of the protrusions on the obtained metal atom-containing particles, calculate the arithmetic mean value, and set it as the average height of the protrusions.

(2) Measurement of the average diameter of the base of the protrusion

The obtained metal atom-containing particles were added to "Technovit 4000" manufactured by Kulzer Co., Ltd. so as to have a content of 30% by weight, and dispersed to prepare an embedding resin for metal atom-containing particle inspection. A cross section of the metal atom-containing particle was cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the metal atom-containing particle dispersed in the embedding resin for inspection.

Then, using a field emission type transmission electron microscope (FE-TEM) ("JEM-ARM200F" manufactured by JEOL Ltd.), set the image magnification to 50,000 times, randomly select 20 particles containing metal atoms, and observe each metal-containing particle. The protrusion of the particle of the atom. Measure the base diameter of the protrusions on the obtained metal atom-containing particles, calculate the arithmetic mean value, and set it as the average diameter of the bases of the protrusions.

(3) Observation of the shape of the protrusion

Using a scanning electron microscope (FE-SEM), set the image magnification to 25,000 times, randomly select 20 metal atom-containing particles, observe the protrusions of each metal atom-containing particle, and investigate the shape types of all protrusions.

(4) Measurement of the thickness of the entire metal part in the part without protrusions

The obtained metal atom-containing particles were added to "Technovit 4000" manufactured by Kulzer Corporation so that the content thereof was 30% by weight, and dispersed to prepare an embedding resin for metal atom-containing particle inspection. A cross section of the metal atom-containing particle was cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the metal atom-containing particle dispersed in the embedding resin for inspection.

Then, using a field emission type transmission electron microscope (FE-TEM) ("JEM-ARM200F" manufactured by JEOL Ltd.), set the image magnification to 50,000 times, randomly select 20 particles containing metal atoms, and observe each metal-containing particle. The metal portion of the non-protruding portion of the particle of the atom. Measure the thickness of the entire metal part in the non-protrusion part of the obtained metal atom-containing particles, calculate the arithmetic mean value, and set it as the thickness of the entire metal part in the non-protrusion part.

(4-1) Measurement of the ratio of the area occupied by the protrusions to the area of the metal atom-containing particles

Using a scanning electron microscope (FE-SEM), set the image magnification to 6000 times, randomly select 20 metal atom-containing particles, and photograph each metal atom-containing particle. Then, the FE-SEM photos were analyzed using commercially available image analysis software.

After performing image processing such as flattening, the area of the protrusions is obtained, and the ratio of the area of the protrusions to the area of the metal atom-containing particles is obtained for 20 metal atom-containing particles, and the average value is defined as the occupied area. area ratio.

(5) Average content of nickel in the entire metal part

Add 5 g of particles containing metal atoms to a mixture of 5 mL of 60% nitric acid and 10 mL of 37% hydrochloric acid to completely dissolve the conductive layer to obtain a solution. Using the obtained solution, the nickel content was analyzed using an ICP-MS analyzer (Inductively coupled plasma mass spectrometry) (manufactured by Hitachi, Ltd.).

(6) Depth measurement of the concave part of the surface part of the substrate particle

The obtained metal atom-containing particles were added to "Technovit 4000" manufactured by Kulzer Co., Ltd. so as to have a content of 30% by weight, and dispersed to prepare an embedding resin for metal atom-containing particle inspection. A cross section of the metal atom-containing particle was cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the metal atom-containing particle dispersed in the embedding resin for inspection.

Then, using a field emission type transmission electron microscope (FE-TEM) ("JEM-ARM200F" manufactured by JEOL Ltd.), set the image magnification to 50,000 times, randomly select 50 particles containing metal atoms, and observe each metal-containing particle. A concave portion of the surface portion of a base particle of an atomic particle. The depth of the concave portion of the surface portion of the substrate particle on the obtained metal atom-containing particles was measured, and the arithmetic mean value was calculated, and set as the depth of the concave portion of the surface portion of the substrate particle.

(7) Compression elastic modulus of particles containing metal atoms (10%K value)

Using a micro-compression testing machine ("Fischer Scope H-100" manufactured by Fischer Corporation), the above-mentioned compressive elastic modulus (10% K value) of the obtained metal atom-containing particles was measured at 23°C to obtain 10% K value.

(8) Measurement of the contact ratio between the peripheral portion of the metal atom-containing particles in the connection structure A1 and the above-mentioned sintered body during press mounting

The obtained metal atom-containing particles were added to "ANP-1" (silver paste) manufactured by Nihon Superior Co., Ltd. in such a manner that the content became 5% by weight, and dispersed to prepare a paste for sintering (composition for connection) things).

As the first connection target member, a power semiconductor element with nickel/gold plating on the connection surface was prepared. As the second connection target member, an aluminum nitride substrate with copper plating on the connection surface was prepared.

The above-mentioned sintering paste was applied on the second connection object member so as to have a thickness of about 70 μm, thereby forming a sintering paste layer. Then, the first member to be connected is laminated on the sintering paste layer to obtain a laminate.

The obtained laminate was preheated on a heating plate at 130°C for 60 seconds, and then a pressure of 10 MPa was applied to the laminate and heated at 300°C for 3 minutes, whereby the above-mentioned metal atoms contained in the paste for sintering The particles are sintered to form a connection portion containing the sintered product and the metal atom-containing particles, and the above-mentioned first and second connection object members are bonded by using the sintered product to obtain a bonded structure A1.

The obtained bonded structure A1 was put into "Technovit 4000" manufactured by Kulzer Co., Ltd. and hardened to prepare an embedding resin for inspection of the bonded structure. A cross section of metal atom-containing particles was cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the bonded structure A1 embedded in the inspection resin.

By using a transmission electron microscope FE-TEM ("JEM-2010FEF" manufactured by JEOL Ltd.) and an energy dispersive X-ray analyzer ("EX-470" manufactured by Horiba) to analyze particles containing metal atoms The element distribution analysis is carried out on the contact part with the sintered body, and the diffusion state of the metal is observed.

Based on the distribution analysis of the diffusion state of the above-mentioned metal, the contact ratio between the outer periphery of the above-mentioned metal atom-containing particles and the above-mentioned sintered body was calculated.

[Criteria for Judgment of Exposure Ratio]

○○○: The contact ratio exceeds 80% and is 100% or less.

○○: The contact ratio exceeds 50% and is 80% or less.

○: The contact ratio exceeds 30% and is 50% or less.

Δ: The contact ratio is not less than 5% and not more than 30%.

×: The contact ratio is less than 5%.

(9) Flatness of the power semiconductor element in the connection structure A1

For the flatness of the power semiconductor element of the connection structure A1 obtained in the evaluation of (8) above, the maximum displacement and the minimum displacement were measured with a high-precision laser displacement meter (manufactured by Keyence Co., Ltd.: LK-G5000). From the measured values obtained, the above-mentioned flatness was obtained from the following formula.

Flatness (μm) = maximum displacement (μm) - minimum displacement (μm)

[Criteria for judging flatness]

○○○: The flatness is 0.5 μm or less.

○○: The flatness exceeds 0.5 μm and is 1 μm or less.

◯: The flatness exceeds 1 μm and is 5 μm or less.

Δ: The flatness exceeds 5 μm and is 10 μm or less.

×: The flatness exceeds 10 μm.

(10) Connection reliability of connection structure A1

Put the bonded structure A1 obtained in the evaluation of (8) above into a thermal shock tester (manufactured by Espec: TSA-101S-W), hold the minimum temperature at -40°C for 30 minutes, and hold it at the maximum temperature of 200°C. The treatment condition of holding time at °C for 30 minutes was set as one cycle, and after 3000 cycles, joint strength was measured using a shear strength tester (manufactured by Rhesca: STR-1000).

[Criteria for judging connection reliability]

○○○: The bonding strength exceeds 50 MPa.

○○: The joint strength exceeds 40 MPa and is 50 MPa or less.

◯: The joint strength exceeds 30 MPa and is 40 MPa or less.

Δ: The bonding strength exceeds 20 MPa and is 30 MPa or less.

x: The bonding strength is 20 MPa or less.

(11) Measurement of the contact ratio between the peripheral portion of the metal atom-containing particles in the connection structure A2 and the above-mentioned sintered body when mounted without pressure

The obtained metal atom-containing particles were added to "ANP-1" (silver paste) manufactured by Nihon Superior Co., Ltd. in such a manner that the content became 5% by weight, and dispersed to prepare a paste for sintering (composition for connection) things).

As the first connection target member, a power semiconductor element having nickel/gold plating on the connection surface was prepared. As the second connection target member, an aluminum nitride substrate with copper plating on the connection surface was prepared.

The said sintering silver paste was apply|coated so that thickness may become about 70 micrometers on the 2nd connection object member, and the paste layer for sintering was formed. Then, the first member to be connected is laminated on the sintering paste layer to obtain a laminate.

Put the obtained laminate into a reflow furnace in a nitrogen atmosphere, and then heat the laminate for 60 minutes under the conditions of a heating rate of 10°C/min and a peak temperature of 250°C, thereby making the sintering paste contained The metal atom-containing particles are sintered to form a connection portion containing the sintered product and the metal atom-containing particles, and the sintered product is used to join the first and second connection object members to obtain a bonded structure A2.

The obtained bonded structure A2 was put into "Technovit 4000" manufactured by Kulzer Co., Ltd. and hardened to prepare an embedding resin for inspection of the bonded structure. A cross section of particles containing metal atoms was cut out using an ion mill ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the bonded structure embedded in the inspection resin.

By using a transmission electron microscope FE-TEM ("JEM-2010FEF" manufactured by JEOL Ltd.) and an energy dispersive X-ray analyzer ("EX-470" manufactured by Horiba) to analyze particles containing metal atoms The element distribution analysis is carried out on the contact part with the sintered body, and the diffusion state of the metal is observed.

Based on the distribution analysis of the diffusion state of the above-mentioned metal, the contact ratio between the outer periphery of the above-mentioned metal atom-containing particles and the above-mentioned sintered body was calculated.

[Criteria for Judgment of Exposure Ratio]

○○○: The contact ratio exceeds 80% and is 100% or less.

○○: The contact ratio exceeds 50% and is 80% or less.

○: The contact ratio exceeds 30% and is 50% or less.

Δ: The contact ratio is not less than 5% and not more than 30%.

×: The contact ratio is less than 5%.

(12) The flatness of the power semiconductor elements in the connection structure A2

The maximum displacement and the minimum displacement were measured with a high-precision laser displacement meter (manufactured by Keyence Co., Ltd.: LK-G5000) for the flatness of the power semiconductor element of the connection structure A2 obtained in the evaluation of (11). From the measured values obtained, the above-mentioned flatness was obtained from the following formula.

Flatness (μm) = maximum displacement (μm) - minimum displacement (μm)

[Criteria for judging flatness]

○○○: The flatness is 0.5 μm or less.

○○: The flatness exceeds 0.5 μm and is 1 μm or less.

◯: The flatness exceeds 1 μm and is 5 μm or less.

Δ: The flatness exceeds 5 μm and is 10 μm or less.

×: The flatness exceeds 10 μm.

(13) Connection reliability of connection structure A2

Put the bonded structure A2 obtained in the evaluation of (11) above into a thermal shock tester (manufactured by Espec: TSA-101S-W), hold it at the minimum temperature of -40°C for 30 minutes, and hold it at the maximum temperature of 200°C. The treatment condition of holding time at °C for 30 minutes was set as one cycle, and after 3000 cycles, joint strength was measured using a shear strength tester (manufactured by Rhesca: STR-1000).

[Criteria for judging connection reliability]

○○○: The bonding strength exceeds 40 MPa.

○○: The joint strength exceeds 30 MPa and is 40 MPa or less.

◯: The joint strength exceeds 20 MPa and is 30 MPa or less.

Δ: The bonding strength exceeds 10 MPa and is 20 MPa or less.

x: The bonding strength is 10 MPa or less.

Table 1 shows the results of performance evaluation of bonded structure A1 and bonded structure A2 obtained using the metal atom-containing particles obtained in each of Examples and Comparative Examples.

It was found that the bonded structure A1 and the bonded structure A2 obtained using the metal atom-containing particles obtained in each example were excellent in both flatness and connection reliability, and thus suppressed occurrence of warpage and cracks. In particular, even the bonded structure A2 produced under the condition of no pressure showed excellent performance.

10‧‧‧Particles containing metal atoms

20‧‧‧sintered body

30‧‧‧Gap Control Particles

50‧‧‧adhesion layer

51‧‧‧The first connection object component

52‧‧‧The second connection target member

A‧‧‧connection structure

Claims (9)

A bonded structure comprising an adhesive layer containing particles containing metal atoms and a sintered body of the metal particles, the particles containing metal atoms are in contact with the sintered system through chemical bonding, and in the section of the bonding layer, the More than 10% of the peripheral length of the particle is in contact with the sintered body, the metal atom-containing particle has a substrate particle and a metal part arranged on the surface of the substrate particle, and nickel, chromium, platinum, and rhodium in the metal part The total amount thereof is 30% by mass or less with respect to the total mass of the metal part. As for the connection structure of claim 1, wherein the metal part has a plurality of protrusions on the outer surface. The bonded structure according to claim 2, wherein the average diameter of the base of the protrusions is not less than 3 nm and not more than 5000 nm. As the bonded structure according to claim 2 or 3, the average height of the protrusions is not less than 1 nm and not more than 1000 nm. As in the connection structure of claim 2 or 3 of the patent application, wherein, in the total surface area of the outer surface of the metal part (100%), the protrusion accounts for more than 30%. Such as the connection structure of any one of items 1 to 3 in the scope of the patent application, wherein the metal part contains gold, silver, tin, copper, germanium, indium, palladium, tellurium, thallium, bismuth, zinc, arsenic, One or more of the group consisting of selenium and alloys containing at least one of these metal elements. The connection structure according to any one of claims 1 to 3 of the patent claims, wherein a plurality of recesses are formed on the surface of the substrate particle. A particle containing a metal atom, which is used for the connection structure of any one of items 1 to 7 of the scope of the patent application, the particle containing a metal atom has a substrate particle and a metal part arranged on the surface of the substrate particle , The total amount of nickel, chromium, platinum and rhodium in the metal part is 30% by mass or less relative to the total mass of the metal part. A connection composition, which contains metal atom-containing particles and metal particles according to claim 8 of the patent application.

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