When you are troubleshooting, it is sometimes useful to disconnect a part of your circuit to see what happens. If your new PCB isn’t perfect, you might also need to add some extra wires or components — not that any of us will ever admit to doing that, of course. When ICs were in sockets, it was easy to do that. [MrSolderFix] shows his technique for lifting pins on SMD devices in the video below.
He doesn’t use anything exotic beyond a microscope. Just flux, a simple iron, and a scalpel blade. Oh, and very steady hands. The idea is to heat the joint, gently lift the pin with the blade, and wick away excess solder. If you do it right, you’ll be able to put the pin back down where it belongs later. He makes the sensible suggestion of covering the pad with a bit of tape if you want to be sure not to accidentally short it during testing. Or, you can bend the pin all the way back if you know you won’t want to restore it to its original position.
He does several IC pins, but then shows that you need a little different method for pins that are near corners so you don’t break the package. In some cases for small devices, it may work out better to simply remove them entirely, bend the pins as you want, and then reinstall the device.
A simple technique, but invaluable. You probably don’t have to have a microscope if you have eagle eyes or sufficient magnification, but the older you get, the more you need the microscope.
Needless to say, you can’t do this with BGA packages. SMD tools used to be exotic, but cheap soldering stations and fine-tipped irons have become the norm in hacker’s workshops.
Most definitely a hack! Genuinely informative and practical, when needed. :-)
it´s a 40 years old hack, that started with DIP packages. Just look at some patched motherboard from the beginning of the eighties, it was quite common: pin lifted (or cut), patch wire soldered.
Obviously this person’s very talented! I modify the technique a bit to work with larger pads: Slide the blade (or some other thin stainless steel shim) under the pin/pad/contact when it’s still molten, and let it set with the blade underneath.
Since solder doesn’t stick to stainless steel (not by accident, at least), this lets you do large contacts one-by-one, without wicking away excess solder. Needs a bit more superheat to make it work, but stainless is not very conductive to heat. Happy soldering!
Yeah, I do something similar. Solderwick off all the solder I can, then lift the pin and slide a bit of polyimide tape between the pin and pad. The pins can usually tolerate about two bends before failing, depending on how far they’re bent, so the less you can bend them the less your chance of having it break entirely.
I believe the video is a repost, and an article was written on it early this year: https://hackaday.com/2024/02/15/lift-those-pins-with-ease/
It’s always possible additional content was added, or the editing changed. I’m quite certain it uses many of the same examples. It doesn’t make it less useful, but it’s one of the déjà vu moments I have here on Hack a Day. Often I’ve watched the video weeks earlier, but not too often there are reposts. I’m guessing it’s not more than once a month.
He has some great soldering tips and tricks on his channel.
You don’t need a blade. My method is to use a sharp pick on the side of the pin, pushing a little sideways and up. Once you move the pin a up a tiny bit, use your desolder wick to remove the solder under the pin and the pin will be free. Use your pick to straighten the pin, and when ready push it down with your soldering iron tip to resolder.
If I need more than that, such as a connector or socket with a large number of pins (or irregular pins) where I can’t use hot air, I use a thin feeler gauge leaf and slide it under one or two pins at a time as I heat them with my soldering iron.
It’s a repost…
Ok, but now show me how to lift a pin on this QFN part.
MrSolderFix is genuinely awesome, so much good information on their youtube channel, needs a permalink on the main hackaday page tbh