PCB Technical - PCB electronic circuit board production process

The PCB industry generally produces according to orders. During the production process, production changes are required due to process or customer requirements, such as changing the process route. In this way, it must be changed in the system. In addition, for each production resource (work center), it is generally operated according to a predetermined scale, and the scale can be changed according to the specific situation, which makes it difficult to plan and arrange. Furthermore, in the PCB industry, only a few materials required for products are tangible, and most materials (including some important materials) cannot be directly reflected in the product. Therefore, building a BOM is also more complicated.

The process is roughly as follows

1 open material

Cut the copper sheets you bought, like paper, in rolls and cut them into small copper sheets of different sizes.

2 internal printing

The inner layer circuit board is printed, and the inner layer circuit of the PCB board is printed on the cut copper sheet.

3 pressing

After the previous process, there is an inner circuit board. In order to protect this circuit, a layer of material needs to be pressed on its front and back to prevent the circuit from being damaged. Can't remember the name of the material.

4 drilling

When we open the case, we see that there are many electronic components on the computer motherboard. These components need holes to be fixed on the board. This process is to drill holes on the board, just like we usually see road repairers use machines to drill on the ground. The hole is the same. Depending on the worn parts of the needles of the punching machine, the company has to spend an annual fee on replacing the damaged needles.

5PTH

Copper (Cu) is used in the hole. The effect is obvious. The newly punched hole may be damaged by the later process. The copper has a relatively large bearing capacity to protect these holes. Why don't you use other elements? There is knowledge in it, not a single sentence can explain it, there is a process of zinc crossing behind.

6 outside lines

Finally, the printing of the outer circuit board can be carried out.

7 Plating

Put a layer of tin on it and etch it. I can't remember the specific content.

8 half test

The test of the semi-finished products will start here. If there are problems with the internal line, they must be repaired in time. Some customers require that the repairs are not allowed and scrapped directly. After being scrapped, there is copper material on this board, which can be recycled (extracted by chemical reaction).

9 solder mask

10 spray tin

11 text

According to customer requirements, engrave text on the board. In modern production, OEM production is very common, usually printing the text required by the customer on the board with ink, and then baking it in a high-temperature baking room.

12 molding

13% finished product test

14% inspection finished product inspection

15 packs

16 lending

The production of PCB boards is assembly line production. The cutting process can be strictly controlled, but it is not easy to control in the middle. After thousands of hard work, it is almost impossible to recognize the original appearance of the piece of copper. WIP can be strictly controlled in the middle of each process, so that we can know whether it can be delivered on time in the end. The output of PCB boards is calculated in feet (units of area), not quantity.

The method of controlling WIP is called CheckPoint. For example, set a checkpoint at the location of process 8 to check how many qualified products there are so far. If there is any abnormality, the reason should be investigated, and the cutting materials should be supplemented in time and put into production.

Add the basic knowledge, the meaning of PCB.

PCB is the most basic component of the information and electronics industry, and belongs to the electronic component industry in the electronic component industry. According to the number of layers, PCB is divided into single-sided board (SSB), double-sided board (DSB) and multi-layer board (MLB); according to flexibility, PCB is divided into rigid printed circuit board (RPC) and flexible printed circuit board ( FPC). In industry research, the PCB industry is generally subdivided into six major subdivisions: single-sided, double-sided, conventional multilayer, flexible, HDI (high-density sintered) board, and package substrate according to the basic classification of the above-mentioned PCB products. industry.