Harima Chemicals, Incorporated

Tetsuyuki Shigesada

Kosuke Inoue

Tadashi Takemoto

Kazuya Ichikawa

Takumi Shiomi

Kensuke Nakanishi

Masao Murata

Kenichi Takeshima

Takuji Sukekawa

Kousuke Inoue

A soldering flux of the present invention contains, as a base resin, an acrylic resin (A) having an acid value of 0 to 70, and an acrylic resin (B) having an acid value of 30 to 230. The acrylic resin (A) is obtained by polymerization of a monomer mixture containing alkyl(meth)acrylate having an alkyl group having carbon atoms of 12 to 23. The acrylic resin (B) is obtained by polymerization of a monomer mixture containing alkyl(meth)acrylate having an alkyl group having carbon atoms of 6 to 10. The acid value of the acrylic resin (B) is higher than the acid value of the acrylic resin (A), and a difference between these two resins is 15 or more.

Flux and solder paste

A solder alloy is a tin-silver-copper solder alloy, and contains tin, silver, copper, bismuth, nickel, and cobalt. Relative to the total amount of the solder alloy, the silver content is 2 mass % or more and 4 mass % or less, the nickel content is 0.01 mass % or more and 0.15 mass % or less, and the cobalt content is 0.001 mass % or more and 0.008 mass % or less.

Solder alloy, solder paste, and electronic circuit board

Growing community of inventors

Hyogo, Japan

Tetsuyuki Shigesada