Engineers, please be careful, this is how PCB boards are copied!

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Engineers, please be careful, this is how PCB boards are copied! [Copy link]

Speaking of PCB copying, you may feel ashamed or angry. Whether you copy the board or someone else copies it, this detailed article about the steps of PCB copying is useful to you. You can see whether your copying steps are "professional", and you can also think about how to prevent others from copying the board based on these steps... The detailed steps of PCB copying also include the copying method of double-sided boards.

Specific steps of PCB copying

1. Get a PCB and first record the model, parameters, and position of all components on paper, especially the direction of diodes and triodes, and the direction of IC notches. It is best to take two photos of the position of components with a digital camera. Nowadays, PCB circuit boards are becoming more and more advanced, and some diodes and triodes on them cannot be seen at all if you are not careful.

2. Remove all multilayer board copying components and remove the tin in the PAD hole. Clean the PCB with alcohol and then put it into the scanner. When scanning, the scanner needs to slightly increase the scanning pixels to get a clearer image. Then use water gauze paper to lightly polish the top and bottom layers until the copper film is shiny, put them into the scanner, start PHOTOSHOP, and scan the two layers in color. Note that the PCB must be placed horizontally and vertically in the scanner, otherwise the scanned image cannot be used.

3. Adjust the contrast and brightness of the canvas to make the part with copper film and the part without copper film have a strong contrast, then convert the image to black and white, check whether the lines are clear, if not, repeat this step. If it is clear, save the image as black and white BMP format files TOP.BMP and BOT.BMP. If you find that there is a problem with the graphics, you can use PHOTOSHOP to repair and correct it.

4. Convert the two BMP format files to PROTEL format files respectively, and import the two layers in PROTEL. If the positions of the PAD and VIA of the two layers are basically overlapped, it means that the previous steps have been done well. If there is a deviation, repeat the third step. Therefore, PCB copying is a very patient job, because a small problem will affect the quality and the matching degree after copying.

5. Convert the BMP of the TOP layer to TOP.PCB. Pay attention to convert it to the SILK layer, which is the yellow layer. Then you can draw lines on the TOP layer and place the components according to the drawing in the second step. Delete the SILK layer after drawing. Repeat until all layers are drawn.

6. Import TOP.PCB and BOT.PCB into PROTEL and combine them into one drawing.

7. Use a laser printer to print TOP LAYER and BOTTOM LAYER on transparent film (1:1 ratio), put the film on the PCB, and compare whether there is any error. If there is no error, you are done.

A copy board that is the same as the original board is born, but this is only half done. It is also necessary to test whether the electronic technical performance of the copy board is the same as the original board. If they are the same, then it is really done.

Remarks: If it is a multi-layer board, you need to carefully polish the inner layer, and repeat the third to fifth steps of copying. Of course, the naming of the graphics is also different, depending on the number of layers. Generally, double-sided board copying is much simpler than multi-layer board. Multi-layer board copying is prone to misalignment, so multi-layer board copying should be particularly careful and cautious (internal vias and non-vias are prone to problems).

Double-sided board copying method

1. Scan the upper and lower surfaces of the circuit board and save two BMP images.

2. Open the copying software Quickpcb2005, click "File" "Open Base Map", and open a scanned image. Use PAGEUP to enlarge the screen, see the pad, press PP to place a pad, see the line and press PT to route... Just like a child tracing, trace it in this software, click "Save" to generate a B2P file.

3. Click "File" "Open Base Map" to open another layer of scanned color image;

4. Click "File" "Open" to open the previously saved B2P file. We can see the board we just copied, superimposed on this picture - the same PCB board, the holes are in the same position, but the circuit connections are different. So we press "Options" - "Layer Settings" to turn off the display of the top layer's circuits and silk screens, leaving only the multi-layer vias.

5. The vias on the top layer are in the same position as the vias on the bottom layer picture. Now we can trace the bottom layer's circuits just like we did when we were children. Click "Save" again - the B2P file now has data on the top and bottom layers.

6. Click "File" "Export as PCB File" to get a PCB file with two layers of data. You can modify the board or re-produce the schematic diagram or directly send it to the PCB board factory for production

Multi-layer board copying method

In fact, the copying of a four-layer board is to copy two double-sided boards repeatedly, and the copying of a six-layer board is to copy three double-sided boards repeatedly... The reason why multi-layer boards are daunting is that we cannot see the internal routing. How can we see the inner world of a precise multi-layer board? - Layering.

There are many ways to layer now, such as chemical corrosion, tool stripping, etc., but it is easy to over-layer and lose data. Experience tells us that sandpaper polishing is the most accurate.

After we have copied the top and bottom layers of the PCB, we usually use sandpaper to polish it, grinding off the surface layer to reveal the inner layer; sandpaper is the ordinary sandpaper sold in hardware stores. Generally, lay the PCB flat, then press the sandpaper and rub it evenly on the PCB (if the board is very small, you can also lay the sandpaper flat, press the PCB with one finger and rub it on the sandpaper). The key point is to lay it flat so that it can be polished evenly.

Silk screen printing and green oil usually fall off with one wipe, and copper wire and copper skin need to be wiped several times. Generally speaking, the Bluetooth board can be wiped in a few minutes, and the memory stick takes about ten minutes; of course, if you have more strength, it will take less time; if you have less strength, it will take more time.

Grinding the board is currently the most common solution for layering, and it is also the most economical. We can find a piece of discarded PCB to try it. In fact, grinding the board is not technically difficult, but it is a bit boring and takes some effort. Don't worry about grinding the board through or grinding your fingers.

During the PCB layout process, after the system layout is completed, the PCB diagram should be reviewed to see whether the system layout is reasonable and whether it can achieve the best effect. Usually, the following aspects can be examined:

1. Whether the system layout ensures the rationality or optimality of the wiring, whether it can ensure the reliable wiring, and whether it can ensure the reliability of the circuit operation. When laying out, it is necessary to have an overall understanding and planning of the signal direction and the power and ground network.

2. Whether the size of the printed circuit board is consistent with the size of the processing drawing, whether it can meet the requirements of the PCB manufacturing process, and whether there are behavioral marks. This requires special attention. The circuit layout and wiring of many PCB boards are designed beautifully and reasonably, but the precise positioning of the positioning connector is neglected, resulting in the designed circuit being unable to connect with other circuits.

3. Whether there is any conflict between components in two-dimensional and three-dimensional space. Pay attention to the actual size of the device, especially the height of the device. When welding layout-free components, the height generally cannot exceed 3mm.

4.Whether the components are arranged in an orderly and neat manner, and whether all components are laid out. When laying out components, not only should the direction and type of signals, and the places that need attention or protection be considered, but also the overall density of the device layout should be considered to ensure uniform density.

5. Whether components that need to be replaced frequently can be replaced easily, and whether the plug-in board can be inserted into the device conveniently. The replacement and connection of components that are frequently replaced should be convenient and reliable.

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Good! I learned something! Thanks for sharing!

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