Hi Technetters,

My first post (although I do work with the estimable Glenn Pelkey so perhaps
my question will garner a response or two) to Technet:

There is debate within my group about the recommended cooling rate (to
optimize grain structure and fatigue resistance of the solder joints) for
eutectic solder (incidentally we are using a convection type reflow oven)...
One camp holds that a fast cooling rate (~ 3C/sec) should be maintained to a
temp. of liquidus MINUS 50C to optimize grain structure. The other camp
contends that what happens below the liquidus temp. is of little consequence
to the grain structure. If anyone can resolve this argument with a materials
science based explanation I would be extremely grateful...

Best Regards,
Tom Ochenas
Maxtek Components Corporation
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