There is an oil called Fusing Oil specifically
designed for fusing
circuit boards (heating the tin-lead plating to a point where it alloys
to solder) that could be used.
I think I have a bottl of that stuff, but I never tried it.
Another route is to use a heat gun on the
back side and use the "slam-bang" method of removing the chips.
Oh yes, I have done this as well.
Whatever method is used, it is very wise to preheat the chips before they
are pulled. Not so fast, but not so light either - the idea is to reduce
the thermal shock when the poor things are exposed to the real heat.
William Donzelli
aw288(a)osfn.org