Breaking epoxy glue spots before desoldering ICs

Say 100 plus SMD IC with 8 or so glue spots under Anyone have a successful method of using that hole in the pcb, if present. I force in 2 of the smallest jeweller's blades but I'm not convinced they do much, hoping there is no tracery hidden under. Then 2 wire loops under the IC with tension over them to assist pull off. Freezer spray while letting the hot air gun heat up - for those like me without the "proper" facilities. Anyone make a jig clamp[ed to the board to force a plunger into the hole ? if so how much force expressed per pin or whatever to break or at least strain the glue bond but without mechanically pushing off IC and traces with it

Reply to
N_Cook
Loading thread data ...

Is there any way you can push a thin screwdriver blade under the IC, then twist? I'd expect THAT to pop the IC loose.

Reply to
William Sommerwerck

There is only about 1/3 mm of free space between rear of IC body and the pcb. I may try putting a joggle in the stem of the blades and grind the blades to a shallower angle and reduce the width and maybe that will be possible.

Reply to
N_Cook

en

Any physical force is likely to tear the traces. I use Chip Quik for the pins first, then pry up the IC using a small jeweler's screwdriver. ChipQuik releases the solder connections so that the traces remain wihtout damage. I have done 1000s of these without any problems, even with the high density pins.

Dan

Reply to
abrsvc

I've got inundated with work. I will be , sometime, taking some 1mm diameter high carbon steel and grinding to a shallow tapering blade and then tapering the edges a bit. Locally heating and trying to put in an elbow. Then a pair of these could get in either side with 0.3mm gap and each turned to expand to 1mm . I guess, would put in enough force to break some of the glue spots at least, and not the traces

Reply to
N_Cook

I think the component glue is easily softened at high temperatures. I think that is by design, so during reflow, when the solder melts the glue allows the component to be lowered fully into the solder. So, if you were to heat the entire chip to reflow temperatures, the glue would likely be quite soft. A hot-air desoldering rig ought to do the job perfectly.

Jon

Reply to
Jon Elson

break

I precool the IC body with freezer spray though. When I grind down the glue spots it smells like standard epoxy

Reply to
N_Cook

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.