A material and method are disclosed such that the material can be used to form functional metal pieces by producing an easily sintered layered body of dried metal paste. On a microstructural level, when dried, the metal paste creates a matrix of porous metal scaffold particles with infiltrant metal particles, which are positioned interstitially in the porous scaffold's interstitial voids. For this material to realize mechanical and processing benefits, the infiltrant particles are chosen such that they pack in the porous scaffold piece in a manner which does not significantly degrade the packing of the scaffold particles and so that they can also infiltrate the porous scaffold on heating. The method of using this paste provides a technique deposition/removal process.

A material and method are disclosed such that the material can be used to form functional metal pieces by producing an easily sintered layered body of dried metal paste. On a microstructural level, when dried, the metal paste creates a matrix of porous metal scaffold particles with infiltrant metal particles, which are positioned interstitially in the porous scaffold's interstitial voids. For this material to realize mechanical and processing benefits, the infiltrant particles are chosen such that they pack in the porous scaffold piece in a manner which does not significantly degrade the packing of the scaffold particles and so that they can also infiltrate the porous scaffold on heating. The method of using this paste provides a technique deposition/removal process.

A brazed joint having excellent tensile strength (TSS and CTS) and a method of production of the same are provided. A sheet combination 200 comprised of steel sheets 210, 220 between which a brazing filler metal 230 is clamped is heated at a temperature of the Ac3 point of the steel sheet (matrix material) or more. The Ar3 point of the regions near the brazing filler metal at the steel sheets is made higher than the Ar3 point of the steel sheets (matrix material), then the quenching start temperature X is made a temperature of the Ar3 point of the steel sheet (matrix material) or less and hot stamping is performed to produce a brazed joint.

A brazed joint having excellent tensile strength (TSS and CTS) and a method of production of the same are provided. A sheet combination 200 comprised of steel sheets 210, 220 between which a brazing filler metal 230 is clamped is heated at a temperature of the Ac3 point of the steel sheet (matrix material) or more. The Ar3 point of the regions near the brazing filler metal at the steel sheets is made higher than the Ar3 point of the steel sheets (matrix material), then the quenching start temperature X is made a temperature of the Ar3 point of the steel sheet (matrix material) or less and hot stamping is performed to produce a brazed joint.

A conductive material for connection parts includes a matrix, a Cu—Sn alloy covering layer having a Cu content of 20 to 70 at % and an average thickness of from 0.2 to 3.0 μm, and a Sn covering layer having an average thickness of from 0.05 to 5.0 μm. The matrix is a copper alloy strip containing specified amounts of Cr and Zr or specified amounts of Fe and P, or a Cu—Zn alloy strip containing a specified amount of Zn. The Cu—Sn alloy covering layer and the Sn covering layer are formed in this order on a surface of the matrix.

A conductive material for connection parts includes a matrix, a Cu—Sn alloy covering layer having a Cu content of 20 to 70 at % and an average thickness of from 0.2 to 3.0 μm, and a Sn covering layer having an average thickness of from 0.05 to 5.0 μm. The matrix is a copper alloy strip containing specified amounts of Cr and Zr or specified amounts of Fe and P, or a Cu—Zn alloy strip containing a specified amount of Zn. The Cu—Sn alloy covering layer and the Sn covering layer are formed in this order on a surface of the matrix.

Aiming at providing a metal particle, an electro-conductive paste, a formed article, and a laminated article that are able to form a highly reliable and high-quality electric interconnect, an electro-conductive bonding portion, or a three-dimensional structure that is less likely to produce the Kirkendall void, this invention discloses a metal particle which include an outer shell and a core part, the outer shell including an intermetallic compound and covering the core part.

A clad material for a cooler is provided by executing production of a tensile strain of 3 to 10% or rolling at a finish rolling ratio of 10 to 25%, and optionally performing a heat treatment for 1 to 8 hours at a temperature within a range from 150 to 400° C., on a clad raw material having a three layer structure of a core material, a first brazing filler metal layer that covers one side (the surface on the side of a cooling water passage) of this core material, and a second brazing filler metal layer that covers the other side (the surface on the opposite side from the cooling water passage). Specific ranges are prescribed for certain properties before and after brazing.

Provided are a Cu ball, a Cu core ball, a solder joint, solder paste and foamed solder, which are superior in the impact resistance to dropping and can inhibit any occurrence of poor joints a junction defect. An electronic component 60 is constructed by joining a solder bump 30 of a semiconductor chip 10 to an electrode 41 of a printed circuit board 40 with solder paste 12, 42. The solder bump 30 is formed by joining an electrode 11 of the semiconductor chip 10 to the Cu ball 20. The Cu ball 20 according to the present invention contains purity which is equal to or higher than 99.9% and equal to or lower than 99.995%, sphericity which is equal to or higher than 0.95, and Vickers hardness which is equal to or higher than 20 HV and equal to or less than 60 HV.

Provided are a Cu ball, a Cu core ball, a solder joint, solder paste and foamed solder, which are superior in the impact resistance to dropping and can inhibit any occurrence of poor joints a junction defect. An electronic component 60 is constructed by joining a solder bump 30 of a semiconductor chip 10 to an electrode 41 of a printed circuit board 40 with solder paste 12, 42. The solder bump 30 is formed by joining an electrode 11 of the semiconductor chip 10 to the Cu ball 20. The Cu ball 20 according to the present invention contains purity which is equal to or higher than 99.9% and equal to or lower than 99.995%, sphericity which is equal to or higher than 0.95, and Vickers hardness which is equal to or higher than 20 HV and equal to or less than 60 HV.