	US 12,377,500 B2
	Lead-free and antimony-free solder alloy, solder ball, and solder joint
Yuuki Iijima, Tokyo (JP); Shunsaku Yoshikawa, Tokyo (JP); Takashi Saito, Tokyo (JP); Kanta Dei, Tokyo (JP); and Takahiro Matsufuji, Tokyo (JP)
Assigned to Senju Metal Industry Co., Ltd., Tokyo (JP)
Appl. No. 17/799,575
Filed by Senju Metal Industry Co., Ltd., Tokyo (JP)
PCT Filed Feb. 8, 2021, PCT No. PCT/JP2021/004571 § 371(c)(1), (2) Date Aug. 12, 2022, PCT Pub. No. WO2021/161954, PCT Pub. Date Aug. 19, 2021.
Claims priority of application No. 2020-023277 (JP), filed on Feb. 14, 2020.
Prior Publication US 2023/0068294 A1, Mar. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. B23K 35/00 (2006.01); B23K 35/02 (2006.01); B23K 35/26 (2006.01); C22C 13/00 (2006.01); C22C 13/02 (2006.01)

CPC B23K 35/262 (2013.01) [B23K 35/0244 (2013.01); C22C 13/02 (2013.01)]

10 Claims

1. A lead-free and antimony-free solder alloy 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,

0.0005 to 0.0045% of Ge, and

optionally one or more selected from the group consisting of Mn, Pd, Au, Pt, Cr, Fe, Co, V, Mo, and Nb each with an upper limit of 0.01% by mass %, and with the balance being Sn,

wherein the lead-free and antimony-free solder alloy satisfies the following relations (1) and (2):

0.013≤(Ag+Cu+Ni+Bi)×Ge≤0.027 relation (1)

Sn×Cu×Ni≤5.0 relation (2)

wherein Ag, Cu, Ni, Bi, Ge, and Sn in the relations (1) and (2) each represent the contents (mass %) thereof in the alloy composition.