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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