Tin-silver-bismuth solders for electronics assembly

Patent · Sun Jan 01 00:00:00 EST 1995

OSTI ID:870014

Vianco, Paul T ^[1]; Rejent, Jerome A ^[1]

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1. Albuquerque, NM

A lead-free solder alloy for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0<5 percent by weight based on the weight of tin effective to depress the melting point of the tin-silver composition to a desired level. Melting point ranges from about 218.degree. C. down to about 205.degree. C. depending an the amount of bismuth added to the eutectic tin-silver alloy as determined by DSC analysis, 10.degree. C./min. A preferred alloy composition is 91.84Sn-3.33Ag-4.83Bi (weight percent based on total alloy weight).

• Research Organization: AT&T
• DOE Contract Number: AC04-76DP00789
• Assignee: Sandia Corporation (Albuquerque, NM)
• Patent Number(s): US 5439639
• OSTI ID: 870014
• Country of Publication: United States
• Language: English

Related Subjects

tin-silver-bismuth
solders
electronics
assembly
lead-free
solder
alloy
electronic
assemblies
composed
eutectic
silver
bismuth
addition
percent
weight
based
effective
depress
melting
tin-silver
composition
desired
level
ranges
218
degree
205
depending
amount
added
determined
dsc
analysis
10
preferred
91
84sn-3
33ag-4
83bi
total
percent based
desired level
alloy composition
weight percent
weight based
preferred alloy
silver alloy
eutectic alloy
solder alloy
lead-free solder
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