About the step description of the board reading method in the circuit board factory

Many customers do not have data on the board, but only one physical circuit board. At this time, it is necessary to copy the board. Cabol Technology has sorted out some steps and methods for board copying in the PCB factory. The following methods can help you understand the process of board copying.

1. Get a circuit board, first record the models, parameters and positions of all the elements on the paper, and finally take two photos of the elements’ positions with a digital camera;
2. Remove all components, remove the tin from the PAD hole, clean the circuit board with alcohol, and then put it into the scanner. When the scanner scans, it needs to slightly increase the scanning pixels to get a clearer image. Start POWTOSHOP, scan the silk screen surface in color mode, save the document and print it for backup;
3. Lightly polish the TOP LAYER and BOTTOM LAYER layers with gauze until the copper film is bright, put them into the scanner, start PHOTOSHOP, scan the two layers in color mode, and save the documents;
4. Adjust the contrast and lightness of the canvas to make the part with copper film contrast strongly with the part without copper film, and then turn the secondary image to black and white to check whether the lines are clear. If not, repeat this step. If the drawing is clear, save it as a black and white BMP file TOP.BMP and BOT.BMP. If you find a problem with the drawing, you can also use PHOTOSHOP to repair it;
5. Convert two BMP files into PROTEL files, and call in two layers in PROTEL. If the positions of PAD and VIA passing through two layers basically coincide, it indicates that the previous steps are well done. If there is any deviation, repeat the third step;
6. Convert BMP of TOP layer to TOP PCB, pay attention to convert to the SILK layer, which is the yellow layer. Then you can trace the lines on the TOP layer, and place the components according to the drawings in step 2. After drawing, delete the SILK layer;
7. Convert the BMP of BOT layer into BOT PCB, pay attention to convert to the SILK layer, which is the yellow layer. Then you can trace lines on the BOT layer, and delete the SILK layer after drawing;
8. In PROTEL, select TOP. PCB and BOT After the PCB is called in, it is OK to combine it into a picture;
9. Use a laser printer to print TOP LAYER and BOTTOM LAYER on the transparent film (1:1) respectively, and put the film on the circuit board to compare whether it is correct. If it is correct, you will be finished.

If it is a multilayer board, you should carefully polish it to the inner layer, and repeat steps 3 to 9 at the same time. Of course, the names of the figures are different. They should be determined according to the number of layers. Generally, the double-sided board is much simpler than the multilayer board. The multilayer board is prone to misalignment. Therefore, the multilayer board should be particularly careful and careful. The internal through holes and non through holes are prone to problems.