Solders

• US 20020057986A1
• Filed: 08/17/2001
• Published: 05/16/2002
• Est. Priority Date: 11/16/2000
• Status: Abandoned Application

• Current Assignee: Quantum Chemical Technologies (Singapore) Pte., Ltd.
• Original Assignee: Quantum Chemical Technologies (Singapore) Pte., Ltd.
• Inventors: Chew, Kai Hwa, Pan, Wei Chih
• Application Number:
  US09/932,059
• Publication Number:
  US 20020057986A1
• Time in Patent Office: Days
• US Class Current: 420/562
• CPC Class Codes: B23K 35/262 Sn as the principal constituent
• CPC Class Codes: C22C 13/00 Alloys based on tin
• CPC Class Codes: C22C 13/02 with antimony or bismuth as the next major constituent

Abstract

A solder comprising: between 87.2% and 89.5% tin; between 4.0% and 4.8% bismuth; between 3.5% and 4.5% indium; and between 3.0% and 3.5% silver.

Claims

1. A solder comprising:

between 87.2% and 89.5% tin;

between 4.0% and 4.8% bismuth;

between 3.5% and 4.5% indium; and

between 3.0% and 3.5% silver.

2. A solder according to claim 1, wherein the solder is a substantially lead-free solder.

3. A solder according to claim 2, wherein the solder is a lead-free solder.

4. A solder according to claim 3, wherein the solder comprises 88.3% tin, 4.5% bismuth, 4.0% indium and 3.2% silver.

5. A method of preparing a solder, comprising the step of mixing tin, bismuth, indium and silver such that:

the proportion of tin in the solder is between 87.2% and 89.5%;

the proportion of bismuth in the solder is between 4.0% and 4.8%;

the proportion of indium in the solder is between 3.5% and 4.5%; and

the proportion of silver in the solder is between 3.0% and 3.5%.

6. A method according to claim 5, wherein the method comprises the addition of substantially no lead to the solder.

7. A method according to claim 6, wherein the method comprises the addition of no lead to the solder.

8. A method according to claim 7, wherein the method comprises the step of mixing tin, bismuth, indium and silver such that:

the proportion of tin in the solder is 88.3%;

the proportion of bismuth in the solder is 4.5%;

the proportion of indium in the solder is 4.0%; and

the proportion of silver in the solder is 3.2%.

9. A method of soldering, comprising the step of using a solder comprising:

between 87.2% and 89.5% tin;

between 4.0% and 4.8% bismuth;

between 3.5% and 4.5% indium; and

between 3.0% and 3.5% silver.

10. A method according to claim 9, comprising the step of using a solder comprising:

88.3% tin;

4.5% bismuth;

4.0% indium; and

3.2% silver

11. A method according to claim 9, wherein the method comprises the step of wave-soldering.