Hi Bob -
Bismuth solders do not have the same mechanic properties as Sn63, have
problems with solder joint failures when tin/lead becomes part of the
solder joint (a low melting alloy of 98C, the solder grain boundaries
become "hot short"), and it oxidizes very badly in a standard wave
solder machine without using an inert gas blanket. The NCMS Lead Free
project is in its final stage of wrapping up their efforts and a
report should be forth coming shortly. There were several bismuth
alloys in their test program and they looked at many processing and
reliability issues. Watch for their report.
Dave Hillman
Rockwell Collins
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Subject: bismuth based solder
Author: [log in to unmask] at ccmgw1
Date: 10/30/96 7:54 PM
I have an assembly that requires a second solder process over a large
area of the assembly, thus the need for a lower temp solder. I'm
looking for the risks associated with the use of bismuth solder
systems. Thanks in advance for your help.
Bob Bickers
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