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I am trying to desolder a micro connector, and one of the through-holes where the connector legs are soldered is so small that I cannot remove the excess solder. I have tried using flux, adding new solder, and using a manual solder sucker. I have also attempted to clear it with a small pin and a fine-tipped soldering iron, but always with the same result. It is next to the mounting hole, i don't want to overheat the board or damage a plated hole. What do you recommend?

Attached are some photos. Sorry for such a basic question, and thanks in advance.

P.S. Apologies for any errors in my English; I am learning the language.

enter image description here

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  • \$\begingroup\$ There are some nice tips on youtube.com/watch?v=9jpotpIO1-U with hole clearing about half-way through. \$\endgroup\$
    – Transistor
    Commented May 16 at 21:26
  • \$\begingroup\$ do you have compressed air? works a lot better than suckers. \$\endgroup\$
    – tobalt
    Commented May 17 at 4:06

3 Answers 3

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Here is trick that works better than many think it should:

Hold the board a few inches off the workbench while heating the solder. Once it is melted strike the bench with the board. Solder is very dense, it usually will clear the hole it one attempt. It doesn't have to be a hard strike, but it should be quick.

I have amazed co-workers that have been soldering for 2+ decades with this trick. Give it a try!

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    \$\begingroup\$ It works, but bear in mind that that imparts quite the negative G's on the board, and should be done with utmost care. Small-ish ceramic components for instance, might not be very happy to be subjected to that kind of stress! \$\endgroup\$
    – MrGerber
    Commented May 17 at 15:19
  • \$\begingroup\$ I almost regret using the word "strike"... a gentle tap is really all that is needed. It really doesn't take much. It is amazing how well this will clear holes. \$\endgroup\$
    – evildemonic
    Commented May 17 at 16:57
  • \$\begingroup\$ @evildemonic Hello. Thank you very much for the reply. Do you mean to tin the hole, hold the board a few inches above the table, and then drop it? \$\endgroup\$
    – condor12
    Commented May 19 at 15:23
  • \$\begingroup\$ I don't drop it, I just gently tap the edge of the board against the workbench. A light tap will suffice. The reason I hold it up while melting the solder is so I can tap it really quickly before it cools back down. \$\endgroup\$
    – evildemonic
    Commented May 20 at 14:42
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If it is old solder (Like someone else did it long ago, and you are trying to clear it out for some reason or replace a part), solder like normal with new solder. Then the easiest way is to put flux on the sports you want to clean off/out, and using a copper wick, put the solder iron on the wick and then the wick on the board. The solder should then suck up into the wick. it might take a few times and pushing the wick into the holes with the solder. But its doable. Or if you get a cheapo solder sucker off Amazon or something, then you just use the solder iron to head up the solder. Put the sucker over the top of your tip and the hole and push the button and the solder sucker will spring up and suck up the molten solder. It will leave it clear and clean.

And the best way, if you do this all the time, get a solder removing station. it has a solder sucker built into the soldering iron.... you put the iron over the solder you want to clean, then push a button and vacuum turns on and sucks all molten solder out. And then its clean and good as new!

There are a ton of Youtube vids on how to do this.

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  • \$\begingroup\$ Note however that it takes a bit of skill not to damage the PCB this way using wick braid, since the heat has to transfer from the braid to the the PCB. It is quite easy to either overheat things or to get the braid stuck in the surface and tearing off traces etc as you remove it. An through-hole desoldering tool is way easier to use without damaging anything. \$\endgroup\$
    – Lundin
    Commented May 17 at 9:18
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With soldering, there's usually the correct way to do something and there's also various more or less dirty tricks - that could get the job done too, but perhaps with unwanted side effects.

In this case the correct way is to use a vacuum desoldering station (through-hole desoldering station). It doesn't need to be a state of the art model. It causes the least damage to the PCB and doesn't come with side effects like solder splatter or ripping off traces by accident. Before you use it, you can manually apply some extra solder and/or flux to the joints, in case the joint is old, oxidized, pre-RoHS etc.

"Solder suckers", wick braids and other misc tips & tricks can be used too, but then you risk damaging the PCB. I've admittedly used wick braids for this plenty of times myself and it is not recommended, because you can easily overheat the board or just as easy not heat enough, meaning that the braid gets stuck on the joint and causing damage. With training you gain skill in this, but that still doesn't make it the correct way.

Desoldering stations are particularly recommended if you also need to save the part you are removing and not just want it gone.

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