PCB Technical - PCB board cutting process and skills

PCB board cutting is an important content in PCB design. However, many designers are reluctant to engage in this work due to the sandpaper grinding plate (a hazardous type of work) and line drawing (a simple repetitive work). Even many designers think that PCB cutting is not a technical job, and junior designers can do this job with a little training. This concept has a certain generality, but like many jobs, there are still some skills in the cutting of PCB boards. If designers master these skills, they can save a lot of time and greatly reduce the amount of labor. Let's talk about this knowledge in detail below.

One, the concept of PCB board cutting

PCB board cutting refers to the process of obtaining the schematic diagram and board diagram (PCB diagram) based on the original PCB board. Its purpose is to carry out later development. Later development includes installation of components, deep testing, circuit modification, etc. Because it does not belong to the category of PCB board cutting and is related to it, only the introduction will not be detailed.

Second, the process of PCB board cutting

1. Remove the components on the original board.

2. Scan the original board to get the graphic file.

3. Grind off the surface layer to obtain the intermediate layer.

4. Scan the middle layer to get the graphic file.

5. Repeat steps 2-4 until all layers are processed.

6. Use special software to convert graphic files into electrical relationship files---PCB diagrams. If you have the right software, the designer only needs to trace the graphics once.

7. Check to complete the design.

Third, the skills of PCB board cutting

The cutting of PCB board, especially the cutting of multi-layer PCB board, is a time-consuming and laborious work, which contains a lot of repetitive labor. The designer must have enough patience and care, otherwise it is very easy to make mistakes. The key to a good cut PCB design is to use appropriate software to replace manual repetitive work, which saves time and is accurate.

1. Scanner must be used during the cutting process

Many designers are used to drawing lines directly on PCB design systems such as PROTEL, PADSOR or CAD. This habit is very bad. The scanned graphic file is not only the basis for conversion into PCB file, but also the basis for later inspection. The use of scanners can greatly reduce labor difficulty and intensity. It is no exaggeration to say that if you can make full use of the scanner, even people with no design experience can complete the PCB board cutting work.

2. Single direction grinding plate

In order to pursue speed, some designers choose two-way grinding plate (that is, grinding away the plate layer from the front and rear surfaces to the middle layer). In fact, this is very wrong. Because the two-way grinding plate is very easy to wear through, causing other layers to be damaged, the result can be imagined. The outer layer of the PCB is the hardest due to the process, copper foil, pads, etc., and the middle layer is the softest. Therefore, the problem is more serious at the most intermediate level, and it is often impossible to polish it. In addition, the materials, hardness, and elasticity of PCB boards produced by various manufacturers are different, and it is difficult to accurately grind them.

3. Choose excellent conversion software

Converting scanned graphics files into PCB files is the key to the whole work. Have a good conversion file. The designer only needs to "photograph the cat and draw the tiger" and trace the graphics once to complete the work. EDA2000 is recommended here, it is really convenient.