US 12,103,114 B2
Lead-free solder alloy composition suitable for use in high-temperature and vibration environments and preparation method thereof
Heung Rak Sohn, Seoul (KR); Bum Gyu Baek, Asan-si (KR); Song Hee Yim, Pyeongtaek-si (KR); and Jun Tae Kim, Busan (KR)
Assigned to KYUNG DONG MTEC CO., LTD., Asan-si (KR)
Filed by KYUNG DONG MTEC CO., LTD., Asan-si (KR)
Filed on Jan. 23, 2020, as Appl. No. 16/751,072.
Claims priority of application No. 10-2019-0009505 (KR), filed on Jan. 24, 2019.
Prior Publication US 2020/0238443 A1, Jul. 30, 2020
Int. Cl. B23K 35/26 (2006.01); B23K 35/02 (2006.01); B23K 35/30 (2006.01); B23K 35/36 (2006.01); B23K 35/362 (2006.01); B23K 35/40 (2006.01); C22C 13/02 (2006.01)
CPC B23K 35/262 (2013.01) [B23K 35/0227 (2013.01); B23K 35/0244 (2013.01); B23K 35/264 (2013.01); B23K 35/3006 (2013.01); B23K 35/302 (2013.01); B23K 35/3601 (2013.01); B23K 35/362 (2013.01); B23K 35/40 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A lead-free solder alloy composition suitable for use in high-temperature and vibration environments, the composition comprising:
a lead-free solder alloy of Sn-(0.5 to 1.5) wt % Cu-(0.1 to 4.0) wt % Bi, Sn-(1.5 to 3.0) wt % Ag-(1.0 to 4.0) wt % Bi, or Sn-(1.5 to 3.0) wt % Ag-(0.5-1.5) wt % Cu-(0.1 to 6.0) wt % Bi; and
0.01 to 0.2 wt % of nanosized ceramic powder as an additive which comprises CrN,
wherein the additive is dispersed as particles around precipitation-strengthened grains of the lead-free solder alloy to have a network structure for preventing dissipating and coarsening of the grains, each of the particles having a size of less than 1,000 nm.