Details of the method of cleaning PCB circuit boards by themselves
Ordinary electronic products have been used for a long time, the circuit board will be covered with dust. If there is too much dust or high air humidity, it can corrode the circuit board or cause a short circuit. If there is a lot of dust on the board it should be cleaned and maintained. System boards for graphic cards, sound cards, network cards and other more complex circuit boards are cleaned before leaving the factory. The purpose is to clean the flux and hand sweat adhering to the circuit board during consumption (although all operators on power-using equipment wear gloves) and other harmful substances. For mass-produced circuit boards, they use special cleaning solutions (often called board cleaning water) and machine washing. For the average user, due to the limited conditions, it is impossible to operate as the circuit board manufacturer, but only need to be careful when operating; cleaning the circuit board is not a difficult and scary thing.
1. Preparation work before cleaning.
Before cleaning, all connectors on the board (including jumpers, cardboard, battery and IC) must be unplugged one by one. Must also remove the potentiometer, transformer and solenoid coil (inductor coil) from the (board batch manufacturer). Remove the circuit board, [Note: Do not do this for non-electronic professionals, because without electronic expertise, disassembly can easily damage parts and circuit boards. But these are related to computers. Basically, there are no such components on the circuit board]. Once water enters the component or water droplets in the gaps are difficult to blow away by compressed air and are difficult to dry. Disassembly must be documented individually to ensure that there are no errors when recovering after cleaning. Also, check for leaks or swelling on the top of the board on the electrolytic capacitor. If so, it must be removed and a record made so that after the board is removed it can be replaced with a new product of equal value. Regarding the circuit board of the computer power supply, the printed circuit board should also be checked for cracks or looseness between the printed circuit board and the component pins (especially high-power components). If cracks or looseness are found they should be repaired immediately. Find a repair solder seam, otherwise it is easy to miss.
(1) Before cleaning, use a clean soft paint brush (preferably with a 1-inch wide brush) and a pressure of about 0.1Mpa (i.e. 1kg / cm2) of monotonic compressed air to remove dust from the board.
(2) Then rinse the circuit board slowly with clean water. Note: Soapy water must be rinsed thoroughly.
(3) In order to carry out cleaning, you can use a special cleaning fluid for cleaning circuit boards (often called circuit board cleaning water). This liquid can be purchased at the store. If there is no washing water, you can perform the following operations: (usually we do not use washing water) first rinse with tap water, taking care that the water flow is soft and not too thick, and brush carefully with a soft brush, and both sides of the circuit board.
(4) After cleaning, use a pressure of about 0.1Mpa [i.e. 1kg / cm2] monotonic compressed air to blow off water droplets, especially jumper plugs, slots (CPU slot, AGP slot, PCI slot, memory slot) inside and at the bottom, the bottom of IC slots, the bottom of chips, BIOS chips and the bottom of IC chips between each other, the bottom of large capacitors, etc., should be stopped from blowing from different directions and try to blow away all the water droplets in the gaps. Assuming that compressed air is not available, a rubber hand pump can be used, but this thing can be very tiring.
(5) Then use a neutral soapy soft brush to carefully and quietly clean every center of the board, especially the jumper plugs, the inside and bottom of the slots (as above), the bottom of the large capacitors, etc. should all be carefully cleaned. During operation, be careful not to touch the small capacitors and other vertically mounted components; if the soap suds are dirty, they must be rinsed with water and then scrubbed with soap again until the washed off soap suds turn white.
(6) Clean the board again using double distilled water or anhydrous alcohol (place the board diagonally with the soldered components side up and dip it into anhydrous alcohol using a clean #10 to #12 paintbrush. (Clean from top to bottom). Carbon tetrachloride is more effective, but is toxic and must be used with care unless necessary. Carbon tetrachloride is not normally recommended. This is the end of the cleaning. This cleaning not only cleans thoroughly, saves money, is environmentally friendly, and is healthy; since washing water is harmful to the body, it is definitely not a good thing to pour the waste liquid after washing down the drain ~~~.
3. Use a pressure of about 0.1Mpa [i.e. 1kg / cm2] of monotonic compressed air to blow away the water droplets, especially the jumper plug, the inside of the slot and the bottom (as above) the bottom of the large capacitor, etc. should stop blowing air from different directions to try to clean all the water droplets in the crevices.
4. After cleaning and processing the PCB board must be completely monotonic before it can be put into use. There are many ways, you can refer to the following methods.
(1) Place it in an air-conditioned room and dry it naturally for more than 36 hours.
(2) Dry in an oven, adjust the temperature of the oven to about 80 degrees Celsius for about 24 hours.
(3) Dry with a hair dryer (for industrial use or for home use). This method requires the hair dryer to be constantly swinging in your hand, which is annoying!
5. Follow the records taken when disassembling the components as a guide and restore all original parts used for disassembly one by one.
6. Check that the installation is satisfactory. The circuit boards of other devices can also be cleaned and maintained as described above.