Provided are a lead-free and antimony-free solder alloy, a solder ball, and a solder joint that have improved shear strength obtained by grain minuteness at a bonded interface and can suppress fusion failure. The lead-free and antimony-free solder alloy having an alloy composition consisting of, by mass%, 0.1 to 4.5% of Ag, 0.20 to 0.85% of Cu, 0.2 to 5.00% of Bi, 0.005 to 0.09% of Ni, and 0.0005 to 0.0090% of Ge with the balance being Sn, and the alloy composition satisfies the following relations (1) and (2): 0.013 ≤ (Ag + Cu + Ni + Bi) x Ge ≤ 0.027 (1), Sn x Cu x Ni ≤ 5.0 (2). Ag, Cu, Ni, Bi, Ge, and Sn in the relations (1) and (2) each represent the contents (mass%) in the alloy composition.

Provided are a lead-free and antimony-free solder alloy, a solder ball, and a solder joint, which have improved shear strength obtained by grain minuteness at a bonded interface and can suppress fusion failure. The lead-free and antimony-free solder alloy has an alloy composition consisting of, by mass %, 0.1 to 4.5% of Ag, 0.20 to 0.85% of Cu, 0.005 to 0.090% of Ni, and 0.0005 to 0.0090% of Ge with the balance being Sn, and the alloy composition satisfies the following relations (1) and (2): 0.006≤(Ag+Cu+Ni)×Ge<0.023 (1), (Sn/Cu)×(Ni×Ge)/(Ni +Ge)<0.89 (2). Ag, Cu, Ni, Ge, and Sn in the relations (1) and (2) each represent the contents (mass %) in the alloy composition.

A semiconductor device includes a semiconductor die including a first side and an opposing second side, a first metallization layer arranged on the first side, a Ni including layer arranged on the second side, wherein the Ni including layer further includes one or more of Si, Cr and Ti, and a SnSb layer arranged on the Ni comprising layer, wherein an amount of Sb in the SnSb layer is in the range of 2 wt % to 30 wt %.

Provided is a metal particle for adhesive paste. The metal particle may include a core including at least one metal; and a shell on at least one surface of the core and including at least one metal and nanoparticles. The metal particle may be a transient liquid phase particle and the at least one metal of the core may have a higher melting point than a melting point of the at least one metal of the shell. In addition, provided are a method of preparing the metal particle for adhesive paste, a composite bonding structure formed from the metal particle for adhesive paste, and a semiconductor device including the composite bonding structure.

Provided is a solder composition containing Sn. The composition comprises: 1.0% by mass or more and 5.0% by mass or less of Cu; 0.1% by mass or more and 0.5% by mass or less of Ni; and more than 0.01% by mass and 0.5% by mass or less of Ge.

A method of soldering includes providing a substrate having a first metal joining surface, providing a semiconductor die having a second metal joining surface, providing a solder preform having a first interface surface and a second interface surface, arranging the solder preform between the substrate and the semiconductor die such that the first interface surface faces the first metal joining surface and such that the second interface surface faces the second metal joining surface, and performing a mechanical pressure-free diffusion soldering process that forms a soldered joint between the substrate and the semiconductor die by melting the solder preform and forming intermetallic phases in the solder. One or both of the first interface surface and the second interface surface has a varying surface profile that creates voids between the solder preform and one or both of the substrate and the semiconductor die before the melting of the solder preform.

Provided is a preform solder including a first metal containing Sn and a second metal formed of an alloy containing Ni and Fe. Alternatively, provided is a preform solder (1) having a metal structure including a first phase (10) that is a continuous phase and a second phase (20) dispersed in the first phase (10), the first phase (10) contains Sn, the second phase (20) is formed of an alloy containing Ni and Fe, and a grain boundary (15) of a metal is present in the first phase (10).

Provided is a preform solder including a first metal containing Sn and a second metal formed of an alloy containing Ni and Fe. Alternatively, provided is a preform solder (1) having a metal structure including a first phase (10) that is a continuous phase and a second phase (20) dispersed in the first phase (10), the first phase (10) contains Sn, the second phase (20) is formed of an alloy containing Ni and Fe, and a grain boundary (15) of a metal is present in the first phase (10).

A flux containing an organic acid, a water-soluble base agent, and a solvent, but not containing water is adopted. In this flux, the organic acid includes 1,2,3-propanetricarboxylic acid. The water-soluble base agent is one or more selected from the group consisting of a nonionic surfactant and a weak cationic surfactant. The content of the 1,2,3-propanetricarboxylic acid is 1% by mass or more and 15% by mass or less with respect to the total amount of the entire flux, the total content of the water-soluble base agent is 30% by mass or more and 65% by mass or less with respect to the total amount of the entire flux, and the total content of the solvent is 30% by mass or more and 65% by mass or less with respect to the total amount of the entire flux. According to this flux, the wettability of solder can be enhanced and ball missing after reflow and flux residue washing is suppressed.

A Magnetic-field melting preform solder that melts by action of an AC magnetic field, wherein the preform solder includes a laminated structure made up of two or more layers, at least two layers constituting the laminated structure is made up of solder material, the at least two layers do not contain ferromagnetic material, each of the at least two layers includes a surface facing with each other, and the surfaces facing with each other are in contact with each other. A bonding method using the preform solder includes a providing the preform solder between an electrode on a substrate and an electrode of an electronic component, and bonding together the electrode on the substrate and the electrode of the electronic component by generating an AC magnetic field around the substrate and thereby melting the preform solder.