First, get a piece of PCB. First, record the type, parameters and position of all the components on paper, especially the direction of the diode, the third stage tube and the direction of IC gap. You can take two pictures of the position of the element with a digital camera. Many PCB boards are becoming more advanced. Some of the upper diode transistors are not noticed at all.
The second step is to remove all the devices and remove the tin from the PAD hole. Clean the PCB with alcohol and put it in the scanner. The scanner needs to raise the scanning pixels slightly in order to get a clearer image. Then the top and bottom layers are slightly polished with water gauze paper, polished until the copper film shines, put into the scanner, start PHOTOSHOP, and sweep the two layers in color mode. Note that the PCB must be placed horizontally and vertically in the scanner, otherwise the scanned image will not be available.
The third step is to adjust the contrast and brightness of the canvas so that the part with copper film and the part without copper film can be strongly contrasted. Then turn the sub-graph to black and white to check whether the lines are clear or not. If not, repeat this step. If clear, save the figure as black and white BMP format files TOP BMP and BOT BMP. If you find that the figure has problems, you can also use PHOTOSHOP to repair and amend it.
PCB copying board
The fourth step is to convert the two BMP format files into PROTEL format files, and to transfer two layers into PROTEL. For example, the positions of PAD and VIA which pass through two layers basically coincide, which shows that the first steps have done well. If there are any deviations, repeat the third step. So it is a very patiently work to copy PCB boards, because a little problem will affect the quality and the matching degree after copy.
Fifth step, convert the BMP of TOP layer into TOP PCB, pay attention to the SILK layer, that is, the Yellow layer, and then you trace in the TOP layer, and place the device according to the drawings of the second step. Delete the SILK layer after drawing. Repeat until all layers are drawn.
The sixth step is to transfer TOP PCB and BOT PCB into PROTEL to form a graph.
The seventh step is to print TOP LAYER and BOTTOM LAYER on transparent film (1:1 ratio) with laser printer. Put the film on that PCB and compare whether there is a mistake. If it is right, you will succeed.