Hybrid lead-free solder wire

Patent metadata

Field	Value
Publication number	US-9802274-B2
Application number	US-201615076386-A
Country	US
Kind code	B2
Filing date	Mar 21, 2016
Priority date	Mar 21, 2016
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A lead-free solder wire includes a core wire with a first alloy and a shell coating layer with a second alloy. The first alloy may be composed of Bi—Ag, Bi—Cu, Bi—Ag—Cu, or Bi—Sb; and the second alloy may be composed of Sn, In Sn—Ag, Sn—Cu, Sn—Ag—Cu, Sn—Zn, Bi—Sn, Sn—In, Sn—Sb or Bi—In, such that the shell coating layer is applied to a surface of the core wire. In another implementation, the lead free solder wire may include a first wire with a first alloy and a second wire with a second alloy. The first alloy may be composed of Bi—Ag, Bi—Cu, Bi—Ag—Cu, or Bi—Sb; and the second alloy may be composed of Sn, Sn—Ag, Sn—Cu, Sn—Ag—Cu, Sn—Zn, Bi—Sn, Sn—In, Sn—Sb or Bi—In, such that the first alloy of the first wire and the second alloy of the second wire are braided together.

First claim

The invention claimed is:

1. A solder wire comprising:
a core wire comprises a first alloy comprising Bi—Ag, Bi—Cu, Bi—Ag—Cu, or Bi—Sb; and
a shell coating layer comprises a second alloy comprising Sn, In, Sn—Ag, Sn—Cu, Sn—Ag—Cu, Sn—Zn, Bi—Sn, Sn—In, Sn—Sb or Bi—In, such that the shell coating layer is applied to a surface of the core wire;
wherein the first alloy has a solidus temperature around 258° C.; and
wherein the second alloy has a solidus temperature that is less than 230° C.

2. The solder wire of claim 1 , wherein the first alloy Bi—Ag comprises from 0 to 30 wt % Ag with the remainder being Bi, such that the first alloy has the solidus temperature of at least around 260° C.

3. The solder wire of claim 1 , wherein the first alloy Bi—Cu comprises from 0-5 wt % Cu with the remainder being Bi, such that the first alloy has the solidus temperature of at least around 270° C.

4. The solder wire of claim 1 , wherein the first alloy Bi—Ag—Cu comprises from 0 to 20 wt % Ag, 0 to 5 wt % Cu with the remainder being Bi, such that the first alloy has the solidus temperature of at least around 285° C.

5. The solder wire of claim 1 , wherein the first alloy Bi—Ag—Cu—X (where X=Al, Au, Co, Ga, Ge, In, Mn, Ni, P, Pd, Pt, Sb, Sn, or Zn) comprises from 0 to 20 wt % Ag, 0 to 5 wt % Cu, and from 0-5 wt % X with the remainder being Bi, such that the first alloy has the solidus temperature of at least around 255° C.

6. The solder wire of claim 1 , wherein the first alloy Bi—Sb comprises from 0 to 20 wt % Sb with the remainder being Bi, such that the first alloy has the solidus temperature of at least around 270° C.

7. The solder wire of claim 1 , wherein the first alloy Bi—Sb—X (where X=Ag, Al, Au, Co, Cu, Ga, Ge, In, Mn, Ni, P, Pd, Pt, Sb, Sn, Zn) comprises from 0 to 20 wt % Sb, 0 to 10 wt % X with the remainder being Bi, such that the first alloy has the solidus temperature of at least around 270° C.

8. The solder wire of claim 1 , wherein the second alloy Sn comprises the solidus temperature of at least 231° C.

9. The solder wire of claim 1 , wherein the second alloy Sn—Ag comprises from 0 to 10 wt % Ag with the remainder being Sn, such that the second alloy has the solidus temperature of at least around 221° C.

10. The solder wire of claim 1 , wherein the second alloy Sn—Cu comprises from 0 to 5 wt % Cu with the remainder being Sn, such that the second alloy has the solidus temperature of at least around 227° C.

11. The solder wire of claim 1 , wherein the second alloy Sn—Ag—Cu comprises from 0 to 10% Ag and from 0 to 5 wt % Cu with the remainder being Sn, such that the second alloy has the solidus temperature of at least around 217° C.

12. The solder wire of claim 1 , wherein the second alloy Sn—Ag—Cu—X (where X=Al, Au, Bi, Co, Ga, Ge, In, Mn, Ni, P, Pd, Pt, Sb, or Zn) comprises from 0 to 10 wt % Ag, 0 to 5 wt % Cu, and 0 to 5 wt % X with the remainder being Sn, such that the second alloy has the solidus temperature of at least around 200° C.

13. The solder wire of claim 1 , wherein the second alloy Sn—Zn comprises from 0 to 20 wt % Zn with the remainder being Sn, such that the second alloy has the solidus temperature of at least around 190° C.

14. The solder wire of claim 1 , wherein the second alloy Bi—Sn comprises from 2 to 60 wt % Sn with the remainder being Bi, such that the second alloy has the solidus temperature of at least around 100° C.

15. The solder wire of claim 1 , wherein the second alloy Bi—Sn—X (X=Ag, Al, Au, Co, Cu, Ga, Ge, In, Mn, Ni, P, Pd, Pt, Sb, or Zn) comprises from 2 to 50 wt % Sn and 0 to 30 wt % X with the remainder being Bi, such that the second alloy has the solidus temperature of at least around 200° C.

16. The solder wire of claim 1 , wherein the second alloy Sn—In comprises 0 to 50 wt % In with the remainder being Sn, such that the second alloy has solidus temperature of at least around 100° C.

17. The solder wire of claim 1 , wherein the second alloy Sn—In—X (X=Ag, Al, Au, Bi, Co, Cu, Ga, Ge, Mn, Ni, P, Pd, Pt, Sb, or Zn) comprises 0 to 50 wt % In and 0 to 30 wt % X with the remainder being Sn, such that the second alloy has the solidus temperature between around 100° C. and around 200° C.

18. The solder wire of claim 1 , wherein the second alloy Bi—In comprises 0 to 50 wt % In with the remainder being Bi, such that the second alloy has the solidus temperature between around 100° C. and around 200° C.

19. The solder wire of claim 1 , wherein the second alloy Bi—In—X (X=Ag, Al, Au, Co, Cu, Ga, Ge, Mn, Ni, P, Pd, Pt, Sb, or Zn) comprises 0 to 50 wt % In and 0 to 30 wt % X with the remainder being In, such that the secondary alloy has the solidus temperature between around 100° C. and around 200° C.

20. The solder wire of claim 1 , wherein the second alloy Sn—Sb comprises 0 to 50 wt % Sb with the remainder being Sn, such that the second alloy has solidus temperature of at least around 230° C.

21. The solder wire of claim 1 , wherein the second alloy Sn—Sb—X (X=Ag, Al, Au, Bi, Co, Cu, Ga, Ge, In, Mn, Ni, P, Pd, Pt, or Zn) comprises 0 to 50 wt % Sb and 0 to 30 wt % X with the remainder being Sn, such that the second alloy has the solidus temperature between around 220° C. and around 250° C.

22. The solder wire of claim 1 , wherein the shell coating layer is applied to the surface of the core wire by dipping the core wire into a molten matrix comprising the second alloy, or electroplating the core wire with a solution comprising the second alloy.

Assignees

• Indium Corp

Inventors

• Zhang Hongwen
• Lee Ning-Cheng

Classifications

• B23K35/0227

  Rods or wires (B23K35/0244 takes precedence) · CPC title

• C22C12/00

  Alloys based on antimony or bismuth · CPC title

• B23K35/264 Primary

  Bi as the principal constituent · CPC title

• B23K35/0266

  flux-cored · CPC title

• B23K35/262

  Sn as the principal constituent · CPC title