US 11,890,702 B2
Solder joint
Hirohiko Watanabe, Hachioji (JP); Shunsuke Saito, Hachioji (JP); and Takeshi Yokoyama, Matsumoto (JP)
Assigned to FUJI ELECTRIC CO., LTD., Kawasaki (JP)
Filed by FUJI ELECTRIC CO., LTD., Kawasaki (JP)
Filed on Dec. 28, 2020, as Appl. No. 17/134,881.
Application 17/134,881 is a continuation of application No. PCT/JP2020/002752, filed on Jan. 27, 2020.
Claims priority of application No. 2019-012501 (JP), filed on Jan. 28, 2019.
Prior Publication US 2021/0138590 A1, May 13, 2021
Int. Cl. B23K 35/26 (2006.01); B23K 1/00 (2006.01); B23K 35/30 (2006.01); C23C 18/16 (2006.01); C23C 18/32 (2006.01); B23K 103/12 (2006.01); B23K 101/40 (2006.01)
CPC B23K 35/262 (2013.01) [B23K 1/0016 (2013.01); B23K 35/302 (2013.01); C23C 18/1637 (2013.01); C23C 18/32 (2013.01); B23K 2101/40 (2018.08); B23K 2103/12 (2018.08)] 10 Claims
OG exemplary drawing
 
1. A solder joint comprising:
a solder joint layer having a melted solder material containing Sn as a main component and further containing Ag and/or Sb and/or Cu; and
a joined body including a Ni—P—Cu plating layer on a surface in contact with the solder joint layer, wherein
the Ni—P—Cu plating layer contains Ni as a main component and contains 0.5% by mass or greater and 8% by mass or less of Cu and 3% by mass or greater and 10% by mass or less of P,
the Ni—P—Cu plating layer has a microcrystalline layer at an interface with the solder joint layer, and the microcrystalline layer includes a phase containing microcrystals of a NiCuP ternary alloy, a phase containing microcrystals of (Ni,Cu)3P, and a phase containing microcrystals of Ni3P.