Solder alloy, solder ball and solder joint

Patent metadata

Field	Value
Publication number	US-2023398643-A1
Application number	US-202118033750-A
Country	US
Kind code	A1
Filing date	Nov 17, 2021
Priority date	Nov 19, 2020
Publication date	Dec 14, 2023
Grant date	—

Abstract

The present invention employs a lead-free and antimony-free solder alloy which has an alloy composition that contains from 1.0% by mass to 4.0% by mass of Ag, from 0.1% by mass to 1.0% by mass of Cu, from 0.1% by mass to 9.0% by mass of Bi, from 0.005% by mass to 0.3% by mass of Ni and from 0.001% by mass to 0.015% by mass of Ge, with the balance being made up of Sn.

First claim

1 . A solder alloy which is free from lead and antimony, the solder alloy having an alloy constitution consisting of: 1.0% by mass to 4.0% by mass of Ag; 0.1% by mass to 1.0% by mass of Cu; 0.1% by mass to 9.0% by mass of Bi; 0.005% by mass to by mass of Ni; 0.001% by mass to 0.015% by mass of Ge; optionally 0.001% by mass to 0.1% by mass of Co; and a balance of Sn.

2 .- 22 . (canceled)

23 . The solder alloy according to claim 1 , wherein an amount of Ag is 3.5% by mass; an amount of Cu is 0.8% by mass; an amount of Bi is 1.0% by mass to 2.0% by mass; an amount of Ni is 0.05% by mass; and an amount of Ge is 0.008% by mass.

24 .- 27 . (canceled)

28 . The solder alloy according to claim 1 , wherein an amount of Ag is 2.0% by mass; an amount of Cu is 0.8% by mass; an amount of Bi is 3.0% by mass to 5.0% by mass; an amount of Ni is 0.05% by mass; and an amount of Ge is 0.008% by mass.

29 . The solder alloy according to claim 1 , wherein an amount of Ag is 1.0% by mass to 3.0% by mass; an amount of Cu is 0.7% by mass to 0.9% by mass; an amount of Bi is 4.0% by mass; an amount of Ni is 0.04% by mass to by mass; and an amount of Ge is 0.006% by mass to 0.009% by mass.

30 . The solder alloy according to any one of claims claim 1 , wherein the alloy constitution satisfies a formula:
0.3≤Ag/Bi≤0.7
wherein Ag and Bi indicate each amount thereof (% by mass) in the alloy constitution.

31 .- 33 . (canceled)

34 . The solder alloy according to claim 1 , wherein an amount of Cu is 0.7% by mass to 1.0% by mass; an amount of Bi is 0.1% by mass to 7.0% by mass; an amount of Ni is 0.040% by mass to by mass; and an amount of Ge is 0.007% by mass to 0.015%.

35 . (canceled)

36 . The solder alloy according to claim 34 , wherein the alloy constitution satisfies a formula:
0.007<Ni/(Ag+Bi)<0.017 wherein Ni, Ag and Bi indicate each amount thereof (% by mass) in the alloy constitution.

37 . The solder alloy according to claim 34 , wherein the alloy constitution satisfies a formula:
46<(Cu/Ni)×(Ag+Bi)<120
wherein Cu, Ni, Ag and Bi indicate each amount thereof (% by mass) in the alloy constitution.

38 . A solder ball formed by a solder alloy of claim 1 .

39 . The solder ball according to claim 38 , wherein an average particle size is 1 μm to 1000 μm.

40 . The solder ball according to claim 38 , wherein a sphericity is 0.95 or more.

41 . The solder ball according to claim 40 , wherein the sphericity is 0.99 or more.

42 . A ball grid array formed by a solder ball of claim 38 .

43 . A solder joint formed by a solder alloy of claim 1 .

44 . The solder alloy according to claim 1 , wherein an amount of Ag is 3.0% by mass to 4.0% by mass; an amount of Cu is 0.7% by mass to 1.0% by mass; an amount of Bi is by mass to 7.0% by mass; an amount of Ni is 0.040% by mass to 0.095% by mass; and an amount of Ge is 0.007% by mass to 0.015% by mass,
wherein the alloy constitution satisfies formulae:
0.007<Ni/(Ag+Bi)<0.017
46<(Cu/Ni)×(Ag+Bi)<120

wherein Cu, Ni, Ag and Bi indicate each amount thereof (% by mass) in the alloy constitution.

45 . The solder alloy according to claim 44 , wherein the amount of Ag is 3.0% by mass to 3.5% by mass; the amount of Bi is 0.3% by mass to 0.7% by mass; the amount of Ni is 0.040% by mass to 0.060% by mass; the amount of Ge is 0.007% by mass to 0.010% by mass; and the amount of Co is 0.005% by mass to 0.010% by mass.

46 . The solder alloy according to claim 1 , wherein an amount of Cu is 0.7% by mass to 1.0% by mass; an amount of Bi is 0.1% by mass to 7.0% by mass; an amount of Ni is by mass to 0.095% by mass; and an amount of Ge is 0.007% by mass to 0.015% by mass,
wherein the alloy constitution satisfies formulae:
0.007<Ni/(Ag+Bi)<0.017
46<(Cu/Ni)×(Ag+Bi)<120

5≤Ag/Bi≤5

wherein Cu, Ni, Ag and Bi indicate each amount thereof (% by mass) in the alloy constitution.

Assignees

• Senju Metal Industry Co

Inventors

• Iijima Yuki
• Yoshikawa Shunsaku
• DEI Kanta
• MATSUFUJI Takahiro
• SUGISAWA Kota

Classifications

• H05K3/346

  Solder materials or compositions specially adapted therefor · CPC title

• B23K35/0244

  Powders, particles or spheres; Preforms made therefrom · CPC title

• B23K35/262 Primary

  Sn as the principal constituent · CPC title

• C22C13/02

  with antimony or bismuth as the next major constituent · CPC title

• B23K2101/40

  Semiconductor devices · CPC title