What Are the Methods for Cleaning Solder Off a Circuit Board?

April 7, 2026

Whether during production or replacement, some solder residue (solder dross) will remain on the circuit board. This residue must be thoroughly cleaned to ensure the board functions properly. With technological advancements and improved technician skills, various methods have emerged to remove this residue. Today, we will introduce two of them.

There are two scenarios for cleaning solder off a circuit board: one requires removing existing solder from the board, and the other involves removing excess solder residue after soldering is completed. Using a solder sucker is recommended. The methods are described separately below:

The first type: Methods for cleaning solder off a circuit board

1. First, shake off the solder from the soldering iron, then re-melt the solder joint. Repeat this process several times.

2. Find a short piece of stranded wire, apply rosin to it, heat it together with the solder joint, and pull out the wire while it is hot. This will remove excess solder.

3. For large areas of solder, use a specialized hot air gun or a solder pot.

The second type: Cleaning excess residue after soldering

1. Use anhydrous ethanol (or alcohol with a concentration above 95%). If the board is very dirty, use a soft brush dipped in alcohol to scrub it.

2. Then, absorb the alcohol with absorbent cotton.

3. Use a solder sucker. For double-sided boards, the process is more complicated. For plated through-holes, use a medical syringe needle: heat the hole with a soldering iron, insert the needle, and rotate it. Alternatively, take a piece of stranded wire (flexible wire) and use it to pull the solder out when it melts.

4. If you don’t have a solder sucker, you can quickly shake the printed circuit board after heating to flick off the solder residue. Be careful and avoid making large movements. When soldering, excess solder on the soldering iron tip can be removed by flicking it off.

These are two common methods in traditional processes for cleaning solder residue, provided here for your reference.