Microwave Tech - The detailed explanation of the PCB board copying method and steps

PCB copy board is to copy PCB circuit board through technical means. Relatively difficult, can also be said to be sophisticated technology. Copying board is not all done pirated use. To develop its functions, it is sometimes necessary to analyze and study the prototype. Due to the need for work, a DC NEC chip-driven module needs to be analyzed. Due to the performance of the NEC inverter driver chip, it is understood not to cut through. Therefore, we hope to keep the characteristics of the original line and copy PCB directly.

The method and steps of PCB line copying comprehensively below:

The first step is to record the models, parameters, and positions of all the components on the paper, especially the direction of the diode, the three-stage tube, and the direction of the IC gap. To draw the principle, because we're not just copying, we're analyzing the principle. Therefore, the type of components must be accurate. The purpose of drawing schematic diagrams is to make later changes and inspections more convenient and accurate. Better have a camera on it. Can be for future reference.

The second step is to remove all the components and remove the tin from all the holes on the pads, otherwise, the accuracy of the pad position may not be high. Clean with alcohol. The top and bottom layers are lightly polished with water yarn paper until the copper film is shiny and then scanned. Do not set the resolution too high when scanning, it is generally recommended to change the resolution to 600DPI, as our current computer may crash if the resolution is too high. To save as BMP format, pay attention to the scan when the PCB should be properly placed. If not, the hole position is not correct, the previous work is discarded. Scan in black and white. Scan images are as follows:

Then open photoshoop to change the threshold and contrast of the image and convert the image to black and white. You need to trim the excess before making changes. In this way, the size of the converted files can be reduced, and the PCB size and size can be more clearly known. Because this board is a double panel and the size of the board is relatively small, I did not remove the silkscreen when copying the board, nor did I polish the copper foil. But it can also achieve the purpose of copying the board. By changing the threshold and selecting the desired value, you can change the image to black and white, removing the gray in the middle. Since the converted drawing will have many independent dots, zooming in will show many small black dots. So I'm going to do the picture. First of all, file conversion is needed to transform the text mode pieces into grayscale. Then choose to go to noise. Choose the right middle value to the right picture. Then reverse the color of the picture, reverse color is the purpose of copper foil color display. If there is no reverse color, the copper foil will have no color display.If it is an underlying image, you also need to mirror the image.

The third step, import PCB, needs a BMP to convert the file into PCB.

1. Graphics files must be black and white images

2. The corresponding layer of the output PCB file is as follows:

layer 1 top layer layer 7 top overlayer

layer 6 bottom layer layer 11 keep-out layer

Choose the picture you just saved, select 1 on the PCB layer (select 6 if it is the bottom layer). Then the out PCB is shocked to generate the PCB file. But for practical purposes, it is usually changed to another layer, such as the screen printing layer.

Now we need to confirm the size of the PCB. Since the size may change during conversion, the BMP file needs to be adjusted. Adjust within/image/canvas size. Until the size fits. Then add the network to the schematic, add components, and trace the line according to the diagram above. Put the components in their original position. Connect the wire. When you're done, delete the yellow line above. The final picture is as follows: Because I made some changes to the schematic diagram, the size is different from the original PCB. It's a chip change. Added the power supply part.

Copy the board in the same way for the other layers, and then check whether the connection is broken. Such a PCB board is finished. In the process of copying the board, we must try to replace the components on the sample with our existing components. In this way, it is unnecessary to introduce new materials. Get our mission done faster.