P2 vs Airgun
Rayman
Posts: 14,181
Had a couple boards that needed P2 rework.
One came out of the oven a bit twisted so pins didn't line up right and wouldn't have worked.
Other one had a bad pin group that I needed. Not sure how I killed that pin group...
Anyway broke out the airgun and seem to have fixed both boards.
First one, with misaligned P2, I tried at 380C for several minutes with no luck, so increased to 400C and got it to move enough, although still pretty sticky.
Second board I cranked up to 450 to remove the bad P2. Then hit the pins with soldering iron to give them a coating of solder. Then added a lot of no clean flux to the pin pads and the central pad.
Applied 400C for about a minute and it dropped in place. Actually twisted a bit and had to push into position.
So, seems like I fixed the two boards. Note this is with leaded solder. Probably a lot harder with the unleaded solder...
Comments
The way I do it is tack solder one corner pin, then check alignment, tack opposite corner pin. After that I solder the whole row of pins together in one continuous solder blob, after that suck out the excess with the de-solder tool. Hakko FM-204
@DigitalBob That's sorta my usual thing too, but use braid instead of de-solder tool. Have to get one of those!
The thing with P2 though, is that want to solder ground pad underneath. That kind of needs the air gun approach...
Good outcome. Great that you could save these boards from the bone pile.
I forgot to mention that I use a liberal amount of solder paste on the heat sink pad, then hot air it from the back.
I can imagine hot air from back being better. Seems hard to do though…
Ground pad