now that I've got the caps off and haven't lifted any pads. The last thing I wanna do is damage anything with a soldering iron that is too hot.
Is there a best temperature?
Is there a best temperature?
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Best temp/watts for Pad cleaning?
- Thread starter smrieck511
- Start date
If a pad is otherwise undamaged, the only time I've ever pulled one off was by repeatedly dwelling way too long with the soldering iron. I mean, really abusing the pad and scorching the board. Usually, if the solder hasn't melted after three seconds then there is a problem that needs to be addressed (tip clean? need flux? not making contact? component too big for soldering iron power?). So, no reason to dwell.
On the other hand, all the other pads that have come off in my hands were already damaged. They weren't actually attached. The board was mushy, the connecting trace was actually disconnected, the glue had come undone, or the previous component had been removed in rough manner (twisting capacitors, etc). In some ways, it is a blessing to learn about a bad pad while performing the rework, rather than have a replacement component break off while moving a computer and causing more damage.
I prefer a STTC-199 Metcal bent chisel tip at a fixed 775 F (413 C) with sn96.5ag03cu.5 lead free solder. This is within the range recommended by Kester. https://www.kester.com/Portals/0/Documents/Knowledge Base/Lead-free-Handsoldering.Final_.4.19.06.pdf
However, many hobbyists prefer lead solder when performing rework, because of the superior wetting. Older boards had leaded solder, so you are going to need follow the standard precautions regardless. Lower temperatures can be used with leaded solder. But, tip temperature is not the cause of pad loss. It's dwelling, physical abuse, previous damage, etc.
Hope this helps,
David
On the other hand, all the other pads that have come off in my hands were already damaged. They weren't actually attached. The board was mushy, the connecting trace was actually disconnected, the glue had come undone, or the previous component had been removed in rough manner (twisting capacitors, etc). In some ways, it is a blessing to learn about a bad pad while performing the rework, rather than have a replacement component break off while moving a computer and causing more damage.
I prefer a STTC-199 Metcal bent chisel tip at a fixed 775 F (413 C) with sn96.5ag03cu.5 lead free solder. This is within the range recommended by Kester. https://www.kester.com/Portals/0/Documents/Knowledge Base/Lead-free-Handsoldering.Final_.4.19.06.pdf
However, many hobbyists prefer lead solder when performing rework, because of the superior wetting. Older boards had leaded solder, so you are going to need follow the standard precautions regardless. Lower temperatures can be used with leaded solder. But, tip temperature is not the cause of pad loss. It's dwelling, physical abuse, previous damage, etc.
Hope this helps,
David
gotcha. Very helpful. Thank you!
I usually put my iron to 650 for SMD work, will depend on whether you’re working with leaded or non-lead solder, which requires a higher temperature.
Clean solder should melt instantly. Leaky caps will turn solder into this crystalline junk, which doesn’t melt well. In that case I add a bit of fresh solder to get it flowing. Then I use (good, fluxed) solder wick to gently sweep the pad clean. Very satisfying.
Clean solder should melt instantly. Leaky caps will turn solder into this crystalline junk, which doesn’t melt well. In that case I add a bit of fresh solder to get it flowing. Then I use (good, fluxed) solder wick to gently sweep the pad clean. Very satisfying.
