Two-sided boards - Desoldering

[multieagle]

I have worked with boards with soldering on one side only. These boards where solder flows through to seal with the top are a real challenge, for me, to desolder a mistake, or failed part. Any suggestions on how best to desolder and replace a part on the MPP pcb?

[Qiaozhi]

I have worked with boards with soldering on one side only. These boards where solder flows through to seal with the top are a real challenge, for me, to desolder a mistake, or failed part. Any suggestions on how best to desolder and replace a part on the MPP pcb?

The easiest way to remove a component is to cut off the pins first, but leaving enough room to grip what's left. Then you can heat one side while pulling out the wire with a small pair of pliers. After that you need to use a desoldering tool and/or desoldering wick. The challenge is usually not so much getting the component out, but unblocking the hole without lifting the pad or any of the tracking. In extreme cases you may have to drill out the hole with a 1mm drill bit, and then repair any damaged tracks. Then you have to remember to solder both the top and the bottom sides of the board, as drilling will eliminate the through-plating from the hole.

Alternatively, you can simply cut off the pins (as before) and solder the replacement onto the wires that are left.

[homefire]

As stated above or Solder Sucker and good hot iron.

[Koala]

Using a solder sucker and iron is a bit of an art. You also need an iron that holds its temperature well.

Soldering iron flat to the PCB on one side of the pin sucker on the other. Also don't let the sucker pull away when the plunger is released. Practice on a old board. The solder will not flow properly unless some fresh flux is added.

Some boards are harder to desolder due to smaller holes. The excellent Silverdog board are quite difficult for this reason.


Solder wick come in different quality. Bought some from DX.com that had good reviews it's nowhere near as effective as some loctite solder wick I had here

[Davor]

Once upon a time I worked in a shop in Miami where every station had two irons, one of which equipped with desoldering hollow bit and a good vacuum pump. It works perfectly for through hole. I've not seen such arrangements gain popularity though.
My weapon of choice is a desoldering braid.

[multieagle]

Once upon a time I worked in a shop in Miami where every station had two irons, one of which equipped with desoldering hollow bit and a good vacuum pump. It works perfectly for through hole. I've not seen such arrangements gain popularity though.
My weapon of choice is a desoldering braid.

I watched a video on Youtube that suggested braid. The follow used liquid flux to assist in soaking up the solder. https://www.youtube.com/watch?v=u_NnU48bmv4

[Davor]

I use colophony resin instead.