PCB component removal technique

[Amie]

Hi all!

I'm not the most skilled person at removing multi legged packages from circuit boards without damage, even with a solder pump or wick.

Here's a hint how it can be done easily on single sided pcb's, if you have a source of compressed air....

************************************
**Put on a pair of safety glasses***
************************************
*Protect the surrounding work area*
************************************

What you do is spray WD 40 thinly on the print side of the board, it helps whet the iron, and stops the solder re sticking to anything. Then apply the hot iron to the joint and when molten quickly remove the iron and blow the solder across the surface of the board.

Its amazing! It leaves the chip or whatever loose in the holes! And also the board can be cleaned up easily too if a repair is being carried out.

Ive not heard of this technique before? I wonder if it is common knowledge, I just thought it would be worth putting up on the forum, it could save a lot of frustrations if members don't have a vacuum de-soldering station.

Thanks,
Amie.

[boater sam]

I have used this technique in the past, hence the burn marks on my bench and clothes!

Its the reverse in a way of using a vacuum pump to suck solder away from the holes.
I have had considerable success with recovering components from unwanted pcbs by heating and smacking the pcb down to eject the solder. Trouble is it splashes everywhere.

If you are stripping lots of pcbs a gas torch and the above method is very quick and does no damage to components on the other side of the board.
Sam.

[BusyBee]

Nice tip Amie although I would have to find something different from WD40 (horrible stuff lol). It sounds a more sensible way of what I do when I get irritated - melt the solder then quickly bang the board on the bench (the same as Sam). It does not work with lots of joints at the same time though. The device for chips I have seen was an attachment for a soldering iron which melts all joints at once. I have never used one. With single sided solder wick works well but I find double sided very tricky. I find it is often it is easier when de-soldering to apply more solder first as the sucker (or wick) has more to go on.

Tracy

[djrm]

I eventually bought one of the low cost ZD-915 type from ebay recentley, I wish I'dbought one twent years ago!. They make unsoldering a breeze and minimizes the risk of damaging board and components. Well worth the cost (approx £82.95 in Jan 2020) Kind regards, David.

[peter scott]

If you are not trying to save the component you are removing then it can help to snip all the legs especially on multilayer boards.

Peter

[Radio Fixer]

Is the ZD-915  de-soldering station any good on old valve radios where there is usually much more solder around the joints.  I normally use a lot of de-soldering wick.  Must have spent a lot on the stuff over the years  .

Also, how good is it on double sided boards with packages?

thanks Gary

[Murphyv310]

Hi.
I know many in this community seem to dislike WD40. Why? It is after all just solvent and light oil. I've used it in electronics for over 40 years and would never be without it.
I use in my desoldering pumps as it stops the solder sticking to the nozzle and improves suction.
Some of the ideas mentioned sound well worth a try.

[Richard_FM]

I have thought about getting a de-soldering station as it seems to make things easier, but can they also be used for normal soldering by changing bits?

[djrm]

Hi All,
I wouldn't try using the desoldering iron for soldering, not least because of its awkward shape. The hollow bit would be a bit odd to work with too.
I found it just fine for double sided boards, ground pads are tricky if you dont get the joint hot enough.
I use it mainly for multi legged components, chips and the like. I usually find the parts will just about drop out after desoldering all the pins.
It does come with tips of various sizes although I would think it will be better on smaller joints rather than things like tag strips and valve bases where there can be a lot of solder.
There a many favourable reviews on utube etc showing the in use, I want disappointed when I got my own.
I'll save up the bad feelings until it breaks - the hot air gun has broken and after buying two replacement heating elements I still haven't got the right one.
Kind regards, David.

[Amie]

Hi all.

Love it or hate it, A little WD on the job seems to make the solder more readily wet to the bit. A little like additional fluxing.

Also, it was the only thing that would work on the contacts of the switching in dads old oscilloscopes!

Some of my recent exploits have been to remove components from new surplus industrial io boards. They are stuffed with 555 timers, opto couplers, zenners, LEDs, 2A ic pnp transistors, relays etc., great stuff for experiments, if they can be removed undamaged.

The boards are also undamaged, and with the WD are easy to clean up.

Through hole plated double sided boards are a bit more difficult, but it does lift the solder from the holes if you can get the blast of air across the plane of the board.

It does work on solder tags in chassis built stuff but cleaning up the waste solder is a pain, and has to be done properly to avoid shorts....

Amie.