PCB Technical - How to make an integrated circuit board

The integrated circuit board is a carrier for loading integrated circuits. But it is often said that the integrated circuit is also brought on the integrated circuit board. The integrated circuit board is mainly composed of silica gel, so it is generally green. The integrated circuit board adopts the semiconductor manufacturing process. Many transistors, resistors, capacitors and other components are fabricated on a small single crystal silicon chip, and the components are combined into a complete device according to the method of multi-layer wiring or tunnel wiring. electronic circuit. It is represented by the letter "IC" in the circuit (also use the text symbol "N", etc.).

The detailed production process of the integrated circuit board is as follows:

1. Print the circuit board. Print out the drawn circuit board with transfer paper, pay attention to the slippery side facing you, generally print two circuit boards, that is, print two circuit boards on one sheet of paper. Choose the circuit board with the best printing effect among them.

2. Cut the copper clad laminate and use the photosensitive board to make the whole process diagram of the circuit board. Copper clad laminate, that is, a circuit board covered with copper film on both sides, cut the copper clad laminate to the size of the circuit board, not too large to save materials.

3. Pretreatment of copper clad laminate. Use fine sandpaper to polish away the oxide layer on the surface of the copper clad laminate to ensure that the carbon powder on the thermal transfer paper can be firmly printed on the copper clad laminate when transferring the circuit board. The standard for polishing is that the surface of the board is bright without obvious Stains.

4. Transfer circuit board. Cut the printed circuit board to a suitable size, and stick the printed circuit board on the copper clad laminate. After alignment, put the copper clad laminate into the heat transfer machine. Make sure that the transfer paper is not misaligned when placing it. Generally, after 2-3 times of transfer, the circuit board can be transferred firmly on the 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.

5. Corrosion circuit board reflow soldering machine. First check whether the printed circuit board 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, the circuit board is removed from the corrosive solution and cleaned, so that a circuit board 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, discharge water first, and then add 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!

6. Circuit board drilling. The circuit board 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 to drill, the circuit board must be pressed firmly. The speed of the drill should not be too slow. The operation of the drill is relatively simple, and it can be done well as long as you are careful. . Please carefully watch the operator's operation.

7. 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 a thin layer of rosin on the side with the circuit, not only to prevent the circuit from being oxidized, but also rosin is also a good flux. Generally speaking, the rosin on the surface of the circuit board will be released within 24 hours. Solidification, 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. The temperature of the hot air blower is as high as 300 degrees, and the air outlet cannot be directed toward combustibles, people and small animals when using it. Safety is still the first requirement.

8. Welding electronic components. After soldering the electronic components on the board, power on, the function is realized, and the production is completed.