PCB News - The technical realization process of PCB copy board

The specific technical steps are as follows:
The first step is to get a PCB. First, record the model, parameters, and positions of all components on the paper, especially the direction of the diode, the transistor, and the direction of the IC gap. It is best to use a digital camera to take two photos of the location of the components. Many PCB circuit boards are becoming more and more advanced. Some of the diode transistors on the above are not noticed at all.
The second step is to remove all the components and remove the tin in the PAD hole. Clean the PCB with alcohol and put it into the scanner. When the scanner scans, you need to raise the scanned pixels slightly to get a clearer image. Then lightly polish the top and bottom layers with water gauze until the copper film is shiny, put them in the scanner, start PHOTOSHOP, and scan the two layers in separately in color. Note that the PCB must be placed horizontally and vertically in the scanner, otherwise the scanned image cannot be used.

The third step is to adjust the contrast, brightness and darkness of the canvas to make the part with copper film and the part without copper film have a strong contrast, then turn the second image into black and white, and check whether the lines are clear. If not, repeat this step. If it is clear, save the picture as black and white BMP format files TOP BMP and BOT BMP. If you find any problems with the graphics, you can also use PHOTOSHOP to repair and correct them.
The fourth step is to convert the two BMP format files to PROTEL format files, and transfer two layers in PROTEL. For example, the positions of PAD and VIA that have passed through the two layers basically coincide, indicating that the previous steps are well done. If If there is a deviation, repeat the third step. Therefore, PCB copying is a work that requires patience, because a small problem will affect the quality and the degree of matching after copying.
The fifth step is to convert the BMP of the TOP layer to TOP PCB. Pay attention to the conversion to the SILK layer, which is the yellow layer. Then you can trace the line on the TOP layer and place the device according to the drawing in the second step. Delete the SILK layer after drawing. Repeat until all the layers are drawn.
The sixth step is to import TOP PCB and BOT PCB in PROTEL, and it will be OK if they are combined into one picture.
The seventh step, use a laser printer to print the TOP LAYER and BOTTOM LAYER on transparent film (1:1 ratio), put the film on the PCB, and compare whether there are errors. If they are correct, you are done. .
A copy board that is the same as the original board was 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 it is the same, it is really done.
Remarks: If it is a multilayer board, you need to carefully polish to the inner layer, and repeat the copying steps from the third to the fifth step. Of course, the naming of the graphics is also different. It depends on the number of layers. Generally, double-sided copying requires It is much simpler than multi-layer boards. Multi-layer copy boards are prone to misalignment. Therefore, multi-layer board copy boards must be especially careful and careful (wherein the internal vias and non-vias are prone to problems).
Double-sided copy board method:
1. Scan the upper and lower layers of the circuit board and save two BMP pictures.
2. Open the copy board software Quickpcb2005, click "File" "Open Base Map" to open a scanned picture. Use PAGEUP to zoom in on the screen, see the pad, press PP to place a pad, see the line and follow the PT line...just like a child drawing, draw it in this software, click "save" to generate a B2P file.
3. Click "File" and "Open Base Image" to open another layer of scanned color image;
4. Click "File" and "Open" again and open the B2P file saved earlier. We see the newly copied board, stacked on top of 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", turn off the top-level line and silk screen display here, leaving only multi-layer vias.
5. The vias on the top layer are in the same position as the vias on the bottom picture. Just trace the lines on the bottom layer just like in childhood. Click "Save" again-the B2P file now has two layers of information on the top and bottom layers.
6. Click "File" and "Export as PCB File", you can get a PCB file with two layers of data, and you can change the board or output the schematic diagram or send it directly to the PCB plate factory for production
Multilayer board copy method:
In fact, the four-layer board copying is repeated copying two double-sided boards, and the sixth layer is repeated copying three double-sided boards... The reason why the multi-layer board is daunting is because we can't see the internal wiring. How do we see the inner layers of a precision multilayer board? -Stratification.
There are many ways to deal with the problem of layering, such as corrosion of potions and stripping of tools, but it is easy to over-separate layers and lose data. Experience tells us that sandpaper polishing is the most accurate.
When we finish copying the top and bottom layers of the PCB, we usually use sandpaper to polish the surface layer to show the inner layer; sandpaper is the ordinary sandpaper sold in hardware stores, generally spread the PCB, and then press and hold the sandpaper to rub evenly on the PCB. (If the board is small, you can also flatten the sandpaper, and rub the sandpaper while pressing the PCB with one finger). The main point is to pave it flat so that it can be ground evenly.
The silk screen and green oil are generally wiped off, and the copper wire and copper skin should be wiped a few times. Generally speaking, the Bluetooth board can be wiped in a few minutes, and the memory stick will take about ten minutes; of course, if you have more energy, it will take less time; if you have less energy, it will take more time.