Abstract: A copper paste for joining is provided that is unlikely to generate voids in a sintering process of a coating film formed thereof to achieve a sufficiently high joining rate to a target member to be joined. The copper paste for joining contains: two or more copper powders having different particle sizes; and a solvent; wherein one of the copper powders has an increase rate of a crystallite size, (D2?D1)/D1×100, of 5% or more, where D1 (nm) represents a crystallite size at 150° C. and D2 (nm) represents a crystallite size at 250° C.; the solvent has a boiling point of 150° C. or higher and lower than 300° C.; and the proportion of the total amount of the copper powders is 88 mass % or more in 100 mass % of the copper paste.

Abstract: A joined body in which a first joining target (11) and a second joining target (13) are joined with a joining layer interposed therebetween is produced. A paste that contains copper particles and an organic solvent is applied to the first joining target (11) to form a coating film (12X). The second joining target (13) is placed on the coating film (12X) to form a stack (15). The stack (15) is heated and pressed to sinter the copper particles contained in the coating film (12X) to form a joining layer. The heating is performed incrementally from a heating start temperature to a highest temperature Tm, and the pressing is performed incrementally from a pressing start pressure to a highest pressure Pm, and control is performed in such a manner that a pressing pressure is 15 MPa or less when a heating temperature reaches 200° C.

Abstract: A method for producing a joined body includes: forming a coating film between a joining target member and a second joining target member, wherein the coating film is formed from a paste containing copper particles, and then heating the coating film to sinter the copper particles to form a joining layer; wherein the copper particles have an average primary particle size of 0.06 ?m or more and 1.0 ?m or less, and include copper particles having an increase rate of the crystallite size, (D2?D1)/D1×100, of 5% or more, where D1 represents the crystallite size (nm) at 150° C. and D2 represents the crystallite size (nm) at 250° C.; and the coating film is held at a heating temperature of 150° C. or more and 350° C. or less for 45 minutes or less to sinter the copper particles.

Abstract: Provided is a copper paste for pressure bonding, the copper paste at least containing two or more copper powders having different shapes and/or particle sizes and a solvent. The copper paste has a viscosity of 10 Pa·s or more and 200 Pa·s or less. The ratio of the total mass of the two or more copper powders to the mass of the copper paste, A, is 0.60 or more and less than 0.82. When the index of bulkiness, H, is defined as H=C/(A×B), H is 0.75 or more and 1.00 or less, wherein A is as defined above, B represents the film thickness of a coating film formed by applying the copper paste to a substrate, and C represents the film thickness of a dried coating film formed by drying the coating film in an air atmosphere at 110° C. for 20 minutes.

Abstract: A method is provided for producing a bonding composition containing copper particles and a second liquid medium. In this production method, the copper particles are produced in a first liquid medium using a wet reduction method, and thus a dispersion of the copper particles is prepared. Subsequently, the first liquid medium in the dispersion is ultimately, finally or eventually replaced with the second liquid medium while the dispersion is kept wet. It is also preferable that the first liquid medium is replaced with another liquid medium one or more times, and the second liquid medium is used in the final replacement. The liquid media are preferably replaced at a temperature of lower than 100° C. The second liquid medium preferably includes one or more of water, alcohol, ketone, ester, ether, and hydrocarbon.

Abstract: A composition for pressure bonding contains a metal powder and a solid reducing agent and has a compressibility of 10% to 90%, the compressibility being expressed by a relationship formula using the thickness A of a dried coating film formed by drying the composition in an air atmosphere at 110° C. under atmospheric pressure for 20 minutes and the thickness B of a sintered body formed by treating the dried coating film in a nitrogen atmosphere at 280° C. under a pressure of 6 MPa for 20 minutes. The solid reducing agent may be BIS-TRIS. Also provided is a bonded structure of conductors in which a bonding portion via which two conductors are bonded together is formed by treating, under pressure, the two conductors and a coating film formed of the composition for pressure bonding provided therebetween.

Abstract: A bonding material includes: a copper foil; and a sinterable bonding film formed on one surface of the copper foil. The bonding film contains a copper powder and a solid reducing agent. The bonding material is used for bonding to a bonding target having, on its surface, at least one metal selected from the group consisting of gold, silver, copper, nickel, and aluminum. The bonding material is also used as a material for wire bonding. A bonded structure is also provided in which a bonding target having a metal layer formed on its surface and a copper foil are electrically connected to each other via a bonding layer formed of a sintered structure of a copper powder, wherein the metal layer contains at least one metal selected from the group consisting of gold, silver, copper, nickel, and aluminum.

Abstract: A bonding sheet includes a copper foil and sinterable bonding films formed on both faces of the copper foil. The bonding films each contain copper particles and a solid reducing agent. The bonding sheet is used to bond to a target object to be bonded having at least one metal selected from gold, silver, copper, and nickel on a surface thereof. A bonded structure includes: a bonded object having at least one metal selected from gold, silver, copper, and nickel on a surface thereof; a copper foil; and a bonding layer including a sintered structure of copper particles; and the bonded object and the copper foil are electrically connected to each other via the bonding layer.

Abstract: A bonded body is provided including: a bonding layer containing Cu; and a semiconductor element bonded to the bonding layer. The bonding layer includes an extending portion laterally extending from a peripheral edge of the semiconductor element. In a cross-sectional view in a thickness direction, the extending portion rises from a peripheral edge of a bottom of the semiconductor element or from the vicinity of the peripheral edge of the bottom of the semiconductor element, and includes a side wall substantially spaced apart from a side of the semiconductor element. Preferably, the extending portion does not include any portion where the side wall and the side of the semiconductor element are in contact with each other. A method for manufacturing a bonded body is also provided.

Abstract: A composition for forming a conductive film contains flat metal particles and a resin. The flat metal particles each have a metal oxide layer in the surface portion thereof. The flat metal particles have a ratio of the thickness of the metal oxide layer to the thickness of the flat metal particle of from 0.010 to 0.300. The thickness of the metal oxide layer is from 0.010 ?m to 2.000 ?m. In the method for manufacturing a conductive film, a composition for forming a conductive film is used, the composition containing flat metal particles and a resin. The composition for forming a conductive film is applied to a base material to form a coating film, and then the coating film is irradiated with light to sinter the coating film, thereby obtaining a conductive film. The flat metal particles each have a metal oxide layer in the surface portion thereof.

Abstract: A bonding composition contains copper powder, a liquid medium, and a reducing agent. The reducing agent contains at least one amino group and a plurality of hydroxyl groups. The reducing agent has a boiling point that is higher than the boiling point of the liquid medium. The reducing agent has a melting point that is equal to or below the sintering temperature of the copper powder. Preferably, the reducing agent is bis(2hydroxyethyl)iminotris(hydroxymethyl)methane. Preferably, the bonding composition has a viscosity of from 10 Pa·s to 200 Pa·s at a shear rate of 10 s-1 at 25° C. Preferably, the bonding composition contains from 0.1 parts to 10 parts by mass of the reducing agent and from 10 parts to 40 parts by mass of the liquid medium with respect to 100 parts by mass of the copper powder.

Abstract: A bonded structure is a structure in which two bonding target members and a bonding portion formed between and adjacent to the bonding target members are bonded together. The bonding portion is made of a material mainly containing copper. In a cross section of the bonded structure taken along a thickness direction, a ratio of a bonded rate between the bonding target members and the bonding portion in a peripheral region of the bonded structure to a bonded rate between the bonding target members and the bonding portion in a central region of the bonded structure is from 0.6 to 0.9. The bonded rate is 0.3 or more.

Abstract: A conductive composition for bonding includes a mix of copper powder carboxylic acid. The carboxylic acid has a branched carbon chain. The copper powder comprises first and second copper particles. The first copper particles have a volume-based cumulative particle size D50 of 0.11 ?m or more and less than 1 ?m at a cumulative volume of 50 vol % in a region of particle sizes of less than 1 ?m in a particle size distribution of the copper powder. The second copper particles have a volume-based cumulative particle size D50 of 1 ?m or more and 10 ?m or less at a cumulative volume of 50 vol % in a region of particle sizes of 1 ?m or more in the particle size distribution of the copper powder. The carboxylic acid is contained in an amount of 6 parts or more and 24 parts or less per 100 parts by mass.

Abstract: A temporary fixing composition is provided that is used to temporarily fix a first bonding target material and a second bonding target material to each other before the two bonding target materials are bonded to each other. The temporary fixing composition contains a first organic component having a viscosity of less than 70 mPa·s at 25° C. and a boiling point of 200° C. or lower and a second organic component having a viscosity of 70 mPa·s or greater at 25° C. and a boiling point of 210° C. or higher. It is preferable that, when thermogravimetry-differential thermal analysis is performed under the conditions at a temperature increase rate of 10° C./min in a nitrogen atmosphere with a sample mass of 30 mg, the 95% mass reduction temperature is lower than 300° C.

Abstract: A bonding composition contains copper powder, a liquid medium, and a reducing agent. The reducing agent contains at least one amino group and a plurality of hydroxyl groups. The reducing agent has a boiling point that is higher than the boiling point of the liquid medium. The reducing agent has a melting point that is equal to or below the sintering temperature of the copper powder. Preferably, the reducing agent is bis(2hydroxyethyl)iminotris(hydroxymethyl)methane. Preferably, the bonding composition has a viscosity of from 10 Pa·s to 200 Pa·s at a shear rate of 10 s?1 at 25° C. Preferably, the bonding composition contains from 0.1 parts to 10 parts by mass of the reducing agent and from 10 parts to 40 parts by mass of the liquid medium with respect to 100 parts by mass of the copper powder.

Abstract: A method is provided for producing a bonding composition containing copper particles and a second liquid medium. In this production method, the copper particles are produced in a first liquid medium using a wet reduction method, and thus a dispersion of the copper particles is prepared. Subsequently, the first liquid medium in the dispersion is ultimately, finally or eventually replaced with the second liquid medium while the dispersion is kept wet. It is also preferable that the first liquid medium is replaced with another liquid medium one or more times, and the second liquid medium is used in the final replacement. The liquid media are preferably replaced at a temperature of lower than 100° C. The second liquid medium preferably includes one or more of water, alcohol, ketone, ester, ether, and hydrocarbon.

Abstract: A bonding sheet includes a copper foil and sinterable bonding films formed on both faces of the copper foil. The bonding films each contain copper particles and a solid reducing agent. The bonding sheet is used to bond to a target object to be bonded having at least one metal selected from gold, silver, copper, and nickel on a surface thereof. A bonded structure includes: a bonded object having at least one metal selected from gold, silver, copper, and nickel on a surface thereof; a copper foil; and a bonding layer including a sintered structure of copper particles; and the bonded object and the copper foil are electrically connected to each other via the bonding layer.

Abstract: A temporary fixing composition is provided that is used to temporarily fix a first bonding target material and a second bonding target material to each other before the two bonding target materials are bonded to each other. The temporary fixing composition contains a first organic component having a viscosity of less than 70 mPa·s at 25° C. and a boiling point of 200° C. or lower and a second organic component having a viscosity of 70 mPa·s or greater at 25° C. and a boiling point of 210° C. or higher. It is preferable that, when thermogravimetry-differential thermal analysis is performed under the conditions at a temperature increase rate of 10° C./min in a nitrogen atmosphere with a sample mass of 30 mg, the 95% mass reduction temperature is lower than 300° C.

Abstract: A bonding material includes: a copper foil; and a sinterable bonding film formed on one surface of the copper foil. The bonding film contains a copper powder and a solid reducing agent. The bonding material is used for bonding to a bonding target having, on its surface, at least one metal selected from the group consisting of gold, silver, copper, nickel, and aluminum. The bonding material is also used as a material for wire bonding. A bonded structure is also provided in which a bonding target having a metal layer formed on its surface and a copper foil are electrically connected to each other via a bonding layer formed of a sintered structure of a copper powder, wherein the metal layer contains at least one metal selected from the group consisting of gold, silver, copper, nickel, and aluminum.

Abstract: A bonded body is provided including: a bonding layer containing Cu; and a semiconductor element bonded to the bonding layer. The bonding layer includes an extending portion laterally extending from a peripheral edge of the semiconductor element. In a cross-sectional view in a thickness direction, the extending portion rises from a peripheral edge of a bottom of the semiconductor element or from the vicinity of the peripheral edge of the bottom of the semiconductor element, and includes a side wall substantially spaced apart from a side of the semiconductor element. Preferably, the extending portion does not include any portion where the side wall and the side of the semiconductor element are in contact with each other. A method for manufacturing a bonded body is also provided.