Desoldering ICs - Best Methods for Removing ICs from Boards

[martyweil]

Removing vintage ICs from boards without damaging them is critical to this area of collecting.

What is the best mothod for desoldering ICs? I'm looking for the best tools and procedures that insure no damage to the chips while also being safe for the person doing the removal.

What is fastest, safest, and least expensive method that you've tried?

Is it worth investing in infrared desoldering systems or are there DIY systems that work just as well for less money?

Any other tips, advice, or best practices to consider?

Thanks.

[mavroxur]

For most of my chip collecting work, I use a heat gun. For repair work, I use my hot air station. The down size about a heat gun is the inability to accurately control temperature or where the heat goes, but to avoid wear and tear on my hot air station, I try to use the cheap-o heat gun when I can.

[martyweil]

[Redeyeburn]

I read somewhere when desoldering old chips, a good method to use was to mix new solder with the old solder before desoldering (as old solder can be a pain to remove), then use a sucker to grab all the solder when you finally do desolder.

I can't vouche for the method as I've never tried it myself, but seems to make sense.

But whatever method you do end up using, practice it on scrap chips and get your method down before attempting on collection pieces.

[martyweil]

I have tried the heat gun method, and it seems to work. Of course, I wouldn't attempt it on a rare chip until I had the method perfected.

[mavroxur]

[smithy]

I use a heat gun (Makita), and it works well. CPUs just drop off the board, or if through hole mounted I heat then use a small screwdriver to help them along. Just watch out for exploding capacitors

Redeyeburn is right if you use lead solder and mavroxur is right if you use unleaded solder. I only use leaded solder for all my work...lead free is horrible...much higher soldering temperature, more risk of damaging components and the solder joints are never as good or long lasting as leaded solder

[martyweil]

Is there acid in capacitors? What other potential dangers are there in using a heat gun? What about fumes?

[smithy]

The electrolyte is usually a weak acid in electrolytic capacitors, but the make up depends on the age etc. If you overheat electrolytic capacitors (esp at temp from a heat gun), they will tend to explode with vigour, so best to wear eye protection. Heating any board at high temp will give off solvents, and older boards would be worse, so again best to wear a mask/breathing protection to be on the safe side

[Guest]

[Doug Haning]

For DIP's I use an air compressor. An air gun at 30 psi is much quicker and more reliable than a solder sucker. Goggles and an exhaust hood are a must. Use your stove top exhaust if you have to, or go outside with a fan. Solder fumes are very bad for you.

[JAC]

Hey guys.. start by understanding the properties of the solder you are trying to reflow.

Start here:
http://en.wikipedia.org/wiki/Soldering


Then understand how solder reflow works here:
http://en.wikipedia.org/wiki/Reflow_solder


Then search for previous discussions, here is example:
http://www.cpu-world.com/forum/viewtopic.php?t=5362



Then you'll know and understand how to use an old oven* to get the best results. Hot air gun works really well with the right technique. Do not use an airgun that is too hot or something like a blowtorch.. they will damage the PCB and the component ou are trying to remove. If the PCB starts discolouring - then the heat source is TOO HOT.


Exploding capacitors?? 30 psi?? really??

Old oven - free
Old baking tray - free
Common sense - priceless


* ( no longer used for food, preferably outside or placed out on the back porch )

[mavroxur]

[quote="JAC"]

Exploding capacitors?? 30 psi?? really??

Old oven - free
Old baking tray - free
Common sense - priceless




It's not the air temperature that causes caps to explode, it's the temperature.