Lead-free alloy containing tin, silver and indium

• US 5,256,370 A
• Filed: 05/04/1992
• Issued: 10/26/1993
• Est. Priority Date: 05/04/1992
• Status: Expired due to Term

• Current Assignee: Indium Corporation
• Original Assignee: Indium Corporation of America Incorporated
• Inventors: Slattery, James A., White, Charles E. T.
• Primary Examiner(s): Yee, Deborah
• Application Number:
  US07/878,050
• Time in Patent Office: 540 Days
• Field of Search: 420/557, 219/146.22
• US Class Current: 420/557
• CPC Class Codes: B23K 35/262 Sn as the principal constituent
• CPC Class Codes: C22C 13/00 Alloys based on tin

Abstract

A low melting point solder alloy comprising effective amounts of tin, silver and indium.

Claims

1. A lead-free solder alloy comprising effective amounts of tin, silver and indium, said composition having a solidus temperature between about 167°

C. and about 212°

C. and a liquidus temperature between about 179°

C. and about 213°

C.

6. The alloy of claim 1, comprising no more than about 6% by weight silver, at least about 4% by weight indium and no more than about 92% by weight tin.

7. The alloy of claim 1, comprising no more than about 6% by weight silver, at least about 4% by weight indium and the remainder tin.

2. An alloy comprising about 70% to about 92% by weight tin, about 1% to about 6% by weight silver and from about 4% to about 35% by weight indium.

3. The alloy of claim 2, further having a solidus temperature between about 167°

C. and about 212°

C. and a liquidus temperature between about 179°

C. and about 213°

C.

4. The alloy of claim 2 comprising about 77.2% by weight tin, about 2.8% by weight silver and about 20% by weight indium.

5. The alloy of claim 4, further having a solidus temperature about 178°

C. and a liquidus temperature about 189°

C.

8. The alloy of claim 2 comprising about 92%by weight tin, about 3% by weight silver and about 5% by weight indium.

9. The alloy of claim 2 comprising about 88% by weight tin, about 3% by weight silver and about 9% by weight indium.

10. The alloy of claim 2 comprising about 84% by weight tin, about 3% by weight silver and about 13% by weight indium.

11. The alloy of claim 2 comprising about 80% by weight tin, about 3% by weight silver and about 17% by weight indium.

12. The alloy of claim 2 comprising about 74% by weight tin, about 3% by weight silver and about 23% by weight indium.

13. The alloy of claim 2 comprising about 71% by weight tin, about 3% by weight silver and about 26% by weight indium.