I use aluminum tape, since it's rigid, conducts heat well and can be tented over plastics without touching them.
I'll go to hot air for removing ICs, but very rarely for SMD caps.
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Nearly torn cap on Mac SE/30, need advice
- Thread starter killvore
- Start date
I use aluminum tape, since it's rigid, conducts heat well and can be tented over plastics without touching them.
I'll go to hot air for removing ICs, but very rarely for SMD caps.
Q: what's a good air temperature for desoldering corroded leads?
On the topic of desoldering.. it seems to me that corroded solder is much harder to liquify than fresh. I just spent my first day using a narrow-nozzle, rework-intent hot air gun. I damaged absolutely no pads, which was encouraging. But I worried the whole time that the long exposures required to get corroded 14- and 16-pin chips (SOICs) to release was going to cook the logic board.
I inched up to 307C before I was able to free some parts. Which made me nervous. Modern reflow ovens are more like 260C, right? Was it higher back in 1989, or is this the effects of corrosion, or do old boards conduct heat better than modern ones (more copper, more substrate)?
On the topic of desoldering.. it seems to me that corroded solder is much harder to liquify than fresh. I just spent my first day using a narrow-nozzle, rework-intent hot air gun. I damaged absolutely no pads, which was encouraging. But I worried the whole time that the long exposures required to get corroded 14- and 16-pin chips (SOICs) to release was going to cook the logic board.
I inched up to 307C before I was able to free some parts. Which made me nervous. Modern reflow ovens are more like 260C, right? Was it higher back in 1989, or is this the effects of corrosion, or do old boards conduct heat better than modern ones (more copper, more substrate)?
Erm don't just reflow - use some epoxy to glue it back down (ideally heat resistant epoxy but in a pinch if you are quick with the iron, any will do).
Then use some conformal coating around the edges to give it a bit more mechanical protection. Only then apply heat and solder down the component on the pad.
Then use some conformal coating around the edges to give it a bit more mechanical protection. Only then apply heat and solder down the component on the pad.
