The flux used during soldering can cause a short circuit, especially if it is not cleaned. However, this depends on the type and content of the flux
1. Active (Acidic) Flux:
– It is usually found in solder pastes and is corrosive.
– Its residues can become *conductive* when combined with moisture and can cause short circuits or leakage currents.
– This type of flux must be cleaned with alcohol or special cleaners.
2. No-Clean Flux:
– As the name suggests, it is a low-conductivity flux type that does not need to be cleaned.
– In most cases, its residues are non-conductive and do not cause a short circuit.
3. Colofone-Based Flux:
– It is widely used for electronic soldering.
– It is normally non-conductive, but it can become conductive over time under high humidity and temperature.
What Should You Do as a Precaution?
– It is best to clean the PCB after soldering, especially if active flux was used, by wiping off flux residues with isopropyl alcohol (IPA) and a brush.
– If you are using No-Clean flux and the circuit is not sensitive, you can leave it without cleaning.
– In power circuits and high-frequency circuits, it is important to clean flux residues in all cases for safety reasons.
If you experience unexpected short circuits or low resistance, it will be useful to check and clean flux residues on the PCB.
Zenit Team