Lead-free desoldering

[bitbyteword3]

I am desoldering an IC with a 20 watt iron and desoldering pump. The ICs are soldered with lead free solder and I have trouble getting the joint to wet;. With minimal tools how can I desolder lead free well?

 

[colin55]

Use some ordinary LEAD solder with rosin (or resin). This will make the solder flow much easier.
LEAD-FREE solder is impossible to work with.

 

[KeepItSimpleStupid]

If the IC is bad, cut the pins and unsolder one at at time. Adding solder and re-sucking also helps sometimes. Make sure your tip is clean and tinned.

 

[aljamri]

Sometimes, if the components soldered both sides, the problem is worse. For that you need a good tip, and sucker.

 

[jpanhalt]

You can use a product called ChipQuick on each pin. ChipQuick is a very low melting solder (also available lead free) that forms a low melting alloy with the lead-free solder that is there. Imagine using something like using solder made of Wood's metal. Once you get the part off, you can use solder wick to clean the pads. Then re-solder in the usual manner. A good flux helps in the removal too.

John

 

[Mr RB]

A 20W iron is unsuitable for IC desoldering, especially on double sided PCBs. A 60W iron is definitely superior to a 40W iron for desoldering, with all the irons I've tested. A 20W iron is not good for much at all.

Check ebay for "60W temperature controlled soldering iron" you can get one quite cheap.

 

[Nigel Goodwin]

Yes, a 20W iron isn't much use, particularly for lead free solder.

But as others have suggested, resolder the joint first with leaded solder, then it will come off easily (but possibly not with a 20W iron).

 

[sparkman001]

Use desolder braid wetted with smd flux, re-wet each joint first with lead solder first, works a treat.

 

[atferrari]

A technique that worked quite well when I started to salvage components was to pre heat the whole board with a heat gun.

That helps a lot. Do it carefully to not go too far.

 

[colin55]

I heat the whole board over a gas ring and pull out the chips quickly with a puller. I have taken 49 chips out of a board and replaced them. And the whole module worked. It was quicker and faster than trying to work out the fault, as no circuit was available.

 

[Gordon Sweet]

I have quite a large collection of old chips unsoldered many years ago mostly from Computer boards. Terrible as it may sound I removed them all using a small blow lamp using meths and screwdrivers. I have never found a chip that failed, but the burning of the boards caused a stink !!

Gordon