The process flow of printed circuit board production varies with the advancement and difference of printed circuit board types and process technology. pcb stackup calculator At the same time, due to the different processes and technologies used by PCB manufacturers, the situation is also different. Different production processes and technologies can be used to produce the same or similar PCBS products. The traditional production process of single, double and multi-layer boards is still the basis of the PCB production process.
Let's share the process of making the circuit board by hand.
1. First of all, we understand that Chinese printed circuit boards need to carry out the printing process. Use transfer paper to print out the circuit board, pay attention to face their own sliding surface, generally can print two circuit boards, that is, print two circuit boards on a piece of paper. The choice of which includes printing technology is the best circuit board.
2. Use the photosensitive plate to cut the copper-covered plate to make the circuit board. 1 oz vs 2 oz Copper clad plate, that is, a circuit board covered with copper film on both sides, cut the copper clad plate into the size of the circuit board, not too large, to save material.
3. Pretreatment of copper-clad plate. The oxide layer on the surface of the copper-clad plate is polished with fine sandpaper to ensure that the toner on the thermal transfer paper can be firmly printed on the copper-clad plate when the circuit board is transferred. The standard of polishing is that the surface of the plate is bright without obvious stains.
4. Transfer the board. Cut the printed circuit board to the appropriate size and then paste the printed circuit board onto the copper-clad sheet. After alignment, the copper-clad plate enters the heat transfer engine. Make sure the transfer paper is not misplaced. Generally, after 2-3 transfers, the circuit board can be firmly transferred to the copper-clad plate. The heat transfer engine has been preheated and the temperature is set at 160-200 degrees Celsius. Due to the high temperature, the operation is safe!
5. corrosion circuit board, reflow furnace. First, check whether the printed circuit board is fully transferred. If there are a few areas that haven't shifted, fill them up with a black pencil. Then it's ready to corrode. When the exposed copper film on the circuit board is completely corroded, the circuit board is removed from the corrosive liquid and cleaned, thus corroding the circuit board. The corrosive solution consists of concentrated hydrochloric acid, concentrated hydrogen peroxide and water in a ratio of 1:2:3. When preparing corrosive solution, it should be drained first, and then added concentrated hydrochloric acid and hydrogen peroxide. If concentrated hydrochloric acid, concentrated hydrogen peroxide or corrosive solution is accidentally splashed on the skin or clothes, rinse with water in time. Due to the use of highly corrosive solution, pay attention to safety when operating!
6. circuit board drilling. The circuit board needs to be inserted with electronic components, so you need to drill holes in the circuit board. Select different bits according to the thickness of the electronic component pin. When drilling with an electric drill, the circuit board must be pressed tightly. Drilling speed development can not be too slow. Please observe the operator carefully.
7. Circuit board pretreatment. After drilling, sand the toner on the circuit board with fine sandpaper and clean the circuit board with water. When the water dries, apply rosin to one side of the circuit. In order to accelerate the curing of the rosin, we use a hot air heater to heat the circuit board, and the rosin can be cured in 2-3 minutes.
8. Weld electronic components. After the electronic components are welded to the circuit board, power is applied.