Can someone suggest the best safe way to desolder/solder a monster QFP
chip?

All I have is a good fine tip 15 watts hand soldering iron.

Thanks

"NAREN PETLU" wrote in message
...
Can someone suggest the best safe way to desolder/solder a monster QFP
chip?

Why do you want to do this? The answer will determine the method.

N

The carbonbased lifeform NAREN PETLU inspired sci.electronics.repair with:
Can someone suggest the best safe way to desolder/solder a monster QFP
chip?

All I have is a good fine tip 15 watts hand soldering iron.

And a 20-20 eye-sight I hope, although that's probably not even good
enough. You'll need at least a good magnifying glass, capable of 5x
manification. The pins are only 0.5mm apart, which is too close for most
people to see whiskers etc. I use a 20x stereo-microscope for this work.

For desoldering I usually sacrify the chip, by bending the pins upwards
one by one with a sharp "surgery" knife while heating the pads. Then
with some dry-wick clean the pads.

For soldering I position the chip on the pads, so that two diagonally
opposite side are corrrectly placed, apply a little solderpaste (don't
even try to use normal solder) on these pads, then keep the chip in place
with a pair of tweezers while heating the solderpaste.
Then apply the paste on a row starting from a not-soldered corner toward
one of the already soldered corners and, while taking care that the pins
you're soldering remain on the pads, heat the pads one by one so that
the solderpaste flows on and around the pins. No solderpaste should
remain between the pads, so use a little as possible.

The solderpaste is easy to apply from a small syringe, I think it can
also be bought in one in small quantities.

Theo
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