Many PCB components like, transformers, relays and GPS modules can be sensitive to liquid cleaning and care has to be taken in choosing the right cleaning process.
Unfortunately, there is no definitive answer as to whether a particular component can withstand a particular liquid cleaning process. You just have to approach it logically.
For example, if you need to clean the PCBA because you need to conformal coat the circuit, then you have to ensure the components can withstand the cleaning process.
Whether they can or cannot is part of the technical specification of the part.
In the case of relays many currently can withstand aqueous cleaning as they are hermetically sealed. This can be the same for other components.
So you must ask the supplier and manufacturer of the components for the information for the part that must be cleaned.
If the parts can be cleaned, the specification for the cleaning process should also specify details. This includes whether you can use aqueous or solvent cleaning technologies, temperature range etc.
Choice then is down to available processes, batch sizes etc. Basically it’s the normal criteria for when deciding to clean.
To ensure the cleaning solution is fully removed, obviously its critical to rinse properly. This might sound obvious, but sometimes this part of the process can take as much time or more than the first cleaning cycle.
Once rinsed, systems have a built in ionic contamination tester which will check the quality of the final rinse water to advise when the work is free of cleaning chemistry and residues. Other processes may use a separate ionic test system after cleaning.
This testing after cleaning is the correct way to ensure correct cleaning, and ensure complete removal of all residues.
If separately the user wants to ensure complete drying, they can revert to a standard drying of 25 minutes at 90 deg. C, which has been proven to ensure full evaporation of water, even underneath low stand off devices. This is of course subject to the components in the assembly being able to withstand these temperatures.
Find out how we can help you with cleaning your circuit board now.
SCH India can provide cleaning processes, conformal coating materials, equipment, services, training and consultation for all areas of the process.
Contact us now to discuss what we can offer you.
Give us a call at (+91) 40 65 897 899 or email your inquiries at firstname.lastname@example.org.