Cleaning a circuit board with an ultrasonic cleaner is the fastest and most efficient way to remove no clean flux, dirt, dust, and other small particles that have accumulated on the board.
Now before we get into the steps there is something very important that you will need to know. This process is for circuit boards with nothing on it or with components that are waterproof only! Also almost all solutions used for a process like this one involve using water which can damage the board if it is not properly removed or protected. Also, for the purpose of cleaning electronic based boards you want to use a saponifier. It is a solution made solely to react to the acid residue left on the board to create soap like substance to wash away easily.
Okay here we go:
Calculate. Every time you use a solution with your ultrasonic cleaner check the dilution ratio. This would be the amount of water you add to the concentrate. The ratio can vary from 1:1 all the way to infinity and beyond. This ratio is extremely important to know and is typically written on the bottle of the solution.
When reading the ratio for solution to water did you notice the section that also had a recommended heat for the ultrasonic? Most of the time the recommended heat for using the ultrasonic ranges between 50°C-65°C but that is varies by solution.
Degassing a solution is very important for properly cleaning any object in the ultrasonic. Degassing will occur naturally if the solution is left alone for hours but to speed up the process, you can use the degas feature. To do so, turn on the degas function for 5-10 minutes. This process removes built up gases in the final solution that can prevent the cavitation process the ultrasonic uses to clean.
Now it is time to place the PCB/electronic board in the solution using gloves or tongs.
Set the timer based on the range the solution will have on its bottle. The recommended time will be somewhere between 3 mins-5 mins dependent on how dirty the board is.
Be patient, be patient, do be in such a hurry. Waiting can be very hard these days but is necessary to let the timer do its job.
Lastly, remove the board from the solution, rinse and let it dry. Also Inspect the board and if it is not cleaned to your satisfaction, put it in for a couple of minutes longer.