Print PCB: Print out the drawn circuit board with transfer paper, pay attention to the slippery side facing you, usually print two circuit boards, that is, print two circuit boards on one paper. Choose the best printing effect one.
Cut the aluminum-based copper clad laminate, and use the photosensitive board to make the whole process diagram of the circuit board. Aluminum-based copper clad laminate is a circuit board with copper film on both sides, cut the copper clad laminate into the size of the circuit board, not too large to save materials.
Aluminum-based copper clad laminates pretreatment. Use fine sandpaper to polish off the oxide layer on the surface of the aluminum-based copper clad laminate to ensure that the carbon powder on the thermal transfer paper can be firmly printed on the copper clad laminate when the circuit board is transferred. The standard for polishing is bright board surface and with no obvious stains.
Transfer PCB. Cut the printed circuit board to a suitable size, and paste the printed circuit board on the copper clad laminate. After alignment, put the aluminum-based copper clad laminate into the heat transfer machine, and make sure that the transfer paper is not misaligned. Generally, after 2-3 times of transfer, the circuit board can be transferred firmly on the aluminum-based copper clad laminate. The heat transfer machine has been preheated in advance, and the temperature is set at 160-200 degrees Celsius. Due to the high temperature, pay attention to safety during operation!
Corrosion circuit board, reflow soldering machine. First check whether the PCB is completely transferred. If there are a few areas that have not been transferred well, you can use a black oil-based pen to repair it. Then it can be corroded. When the exposed copper film on the circuit board is completely corroded, get the PCB from the corrosive solution and clean it, then a PCB is corroded. The composition of the corrosive solution is concentrated hydrochloric acid, concentrated hydrogen peroxide, and water in a ratio of 1:2:3. When preparing the corrosive solution, add water first, and then concentrated hydrochloric acid and concentrated hydrogen peroxide. Be careful of splashing on the skin or clothes and wash them with clean water in time. Because of the use of strong corrosive solutions, you must pay attention to safety during operation!
PCB drilling. The PCB needs to be inserted with electronic components, so it is necessary to drill the circuit board. Choose different drill pins according to the thickness of the electronic component pins. When using the drill, PCB must be pressed firmly. The drill speed cannot be too slow. Please carefully watch the operator’s operation.
Circuit board pretreatment. After drilling, use fine sandpaper to polish off the toner on the circuit board, and clean the circuit board with water. After the water dries, apply rosin to the side with the circuit. In order to speed up the solidification of the rosin, we use a hot air blower to heat the circuit board, and the rosin can solidify in only 2-3 minutes.
Welding electronic components. After soldering the electronic components on the board, turn on the power.