17 Nov
2006
17 Nov
'06
11:06 a.m.
On 17 Nov 2006 at 10:29, Chris M wrote:
so if you presumably (probably? possibly?) eliminate
any heat getting to the ic's innards by the method I
described, you're likely doing no damage to it?
I'm not sure about this, but it would seem that using water to cool
the body of an IC while needing to apply more heat to the pin to melt
the solder would make for a steeper temperature gradient through the
packaging. Could this in fact be counter-productive by increasing
stresses on the encapsulation?
I really don't worry too much about overheating a chip by desoldering
it. Consider that what destroys a chip thermally during operation is
localized overheating within the die itself. Using a temperature-
controlled iron would seem to elminate most overheating problems.
As another example, consider the use of ovens for mounting SMT
devices. No water there--and the small, low thermal-mass SMT
devices seem to survive just fine.
Cheers,
Chuck