Hello everyone, I am Rose. Welcome to the new post today. Today I will introduce the differences of copying methods between double-sided and multi-layer PCBs.

The technical realization of PCB copying is as simple as scanning the circuit board to be copied, recording the precise component positions, removing the components to create a bill of materials (BOM) and arrange for material procurement, and then sending the empty board to the plate manufacturing factory with the PCB file for production. After the PCB board is created, the purchased components are welded to it. The circuit board and debugging are then tested.

Ⅰ.  The specific steps of PCB copying

1. Obtain a PCB, then write down the models, parameters, and locations of all the important components on the paper, paying particular attention to the direction of the diodes, triodes, and IC notch. It is advisable to use a digital camera to snap two images of the element's location. The sophistication of PCB circuit boards today is increasing. Some of the aforementioned diodes and triodes cannot be seen at all.

2. Take out the tin from the PAD hole and all of the multi-layer board components. After cleaning the PCB with alcohol, place it in the scanner. To produce a crisper image during scanning, the scanner needs to slightly increase the scanned pixels. Once the copper film is shiny, lightly buff the top and bottom layers with wet gauze paper, place them in the scanner, launch PHOTOSHOP, and scan the two layers in color. Remember that for the scanned image to be available, the PCB must be positioned both horizontally and vertically in the scanner.

3. Change the second image to black and white and make sure the lines are apparent. If not, repeat steps 3 and 4 to adjust the canvas's contrast and brightness such that the area covered with copper film and the area that isn't have a strong contrast. If it is obvious that the images were saved as the files TOP.BMP and BOT.BMP in the BMP format, if you find any problems with the graphics, you can also use PHOTOSHOP to repair and correct them.

4. Transfer two levels in PROTEL from the two BMP format files into their corresponding PROTEL format files. For instance, the positions of PAD and VIA after the two layers are nearly identical, demonstrating the effectiveness of the initial procedures. The third step should be repeated if there is any variance. Therefore, PCB copying is a task that requires patience because even a minor issue will have an impact on the copy's quality and degree of matching.

5. Change the TOP layer's BMP to TOP.

PCB, be sure to change it to the SILK layer (the yellow layer), after which you can draw a line on the TOP layer and, in the following step, position the device in accordance with the drawing. After drawing, delete the SILK layer, and repeat until all layers are drawn.

6. Import TOP.PCB and BOT.PCB into PROTEL and merge them into a single image.

7. Print the TOP LAYER and BOTTOM LAYER on the transparencies in a 1:1 ratio using a laser printer, then place the film on the PCB and check for errors. Upon confirmation, you are done.

A duplicate of the original board was created, however it was incomplete. Testing is also required to see if the clone board's electronic technical performance is identical to that of the original board. If so, it is effectively finished.

Remarks: If the board has multiple layers, it should be properly polished down to the inner layer while also copying the third through fifth processes. Of course, the names given to the graphics vary as well, and they should be chosen based on the number of layers. The double-sided board should typically be replicated. The multi-layer copy board should be extremely cautious and meticulous because it is much simpler than the multi-layer board and the multi-layer copy board is prone to improper alignment (the internal vias and non-conductive holes are prone to problems).