PCB board Reading/Scan process
PCB board reading process
A PCB is a printed circuit board without components, while a printed circuit board with components is called a PCBA. The following is the PCB board reading process with components.
1. Scan the picture of the circuit board
Note: Because there may be small patch components under large components, you can scan them first and then remove the large ones and sweep them again.
2. The patch
Remove all components and remove the tin from the PAD hole. Clean the PCB with plate washing water, and then put it into the scanner. When the scanner scans, select appropriate pixels according to the precision of the board, so as to get a clearer image. sweep the screen printing surface in color, save the file and print it out for later use.
Note: Attention should be paid to the polarity and direction of the components when disassembling the plates.
3. Make BOM
Referring to the picture of the circuit board in the first step, record the models, parameters, and positions of all components on paper, especially the direction of the diode, the direction of the IC gap, etc., and finally make the BOM table;
4. The grinding plate
Slightly polish the TOP LAYER and BOTTOM LAYER with water yarn paper until the copper film shines. Put it into the scanner, start Photoshop, and sweep the two layers in color.
5. Adjust the contrast and shade of the canvas so that the part with copper film and the part without copper film are in strong contrast. Then turn the image to black and white and check whether the lines are clear. If it is clear, save the drawing as black and white BMP format files top. BMP and bot.bmp. If there is any problem with the drawing, you can also use Photoshop to repair and correct it.
6. Start the PCB board reading software Protel, enter the scanned PCB board pictures in the file menu, convert the two BMP files into Protel files respectively, and enter two layers in Protel. If the positions of PAD and Via after the two layers are basically identical, it shows that the previous steps have been done well.
7. Convert the BMP of the TOP layer to the TOP.PCB, pay attention to the SILK layer, then you trace the line in the TOP layer, and place the device according to the drawing in step 2. Delete the SILK layer after drawing.
8. Convert the BMP of the BOT layer to the BOT.PCB, as above, to the SILK layer, and then you will trace the line in the BOT layer. Delete the SILK layer after drawing.
9. Put top. PCB and bot. PCB in PROTEL and combine them into one drawing.
10. Use the laser printer to print the TOP LAYER and BOTTOM LAYER on transparent film (1:1 ratio), put the film on that piece of PCB, compare if there is any error, if yes, a simple double panel is made!
