PCB counter-copy board countermeasures

PCB copy board technology implementation process in simple terms, is to first scan copy board circuit boards, record the details of the components, and components removed to make material list (BOM) and arrange the material purchasing, empty plate image is scanned into the software processing back into PCB copy board figure file, and then send a PCB file to plate plate making factory, After the board is made, the purchased components will be welded to the PCB board made, and then through the PCB test and debugging.

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PCB counter-copy board countermeasures

Specific steps of PCB copying board:

The first step, get a PCB, first of all on the paper to record all the components of the model, parameters, and position, especially the diode, three pipe direction, IC notch direction. It is best to take two pictures of the position of the ski with a digital camera. Now the PCB circuit board is more and more advanced above the diode triode some do not pay attention to simply can not see.

The second step, remove all the multilayer board copying parts, and remove the tin in the PAD hole. Clean the PCB with alcohol and place it into a scanner that scans at slightly higher pixels to get a sharper image. Then, polish the top and bottom layers lightly with water yarn paper until the copper film is shiny. Put them into the scanner, start PHOTOSHOP, and brush the two layers separately in color. Note that PCB must be placed horizontally and vertically in the scanner, otherwise the scanned image can not be used.

The third step, adjust the contrast and shade of the canvas, so that the part with copper film and the part without copper film contrast strongly, and then turn the subgraph to black and white, 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 there is a problem with the picture, you can use PHOTOSHOP to repair and correct it.

The fourth step is to convert the two BMP files into PROTEL files respectively, and transfer two layers into PROTEL. For example, the positions of PAD and VIA that have passed the two layers basically coincide, indicating that the previous steps have been done well. If there is any deviation, repeat the third step. Therefore, PCB board copying is a very patient work, because a little problem will affect the quality and the matching degree after board copying.

Step 5, convert TOP layer BMP to TOP.PCB, make sure to convert SILK layer, that is the yellow layer, then you trace the line on TOP layer, and place the device according to the drawing of step 2. Delete the SILK layer after painting. Repeat until all layers are drawn.

Step 6, in PROTEL, call in top. PCB and bot. PCB, and combine them into one figure.

Step 7, use laser printer to print the TOP LAYER and the BOTTOM LAYER to transparent film (1:1 ratio), put the film on that PCB and compare if it is wrong, if it is right, you are done.

A copy of the original board was created, but it was only half done. Have a test even, the electronic technology performance that tests copy board is same as original board. If it’s the same then it’s really done.

Remark: If it is a multi-layer board but also carefully polished to the inside of the inner layer, at the same time repeat the third to the fifth step of copying board steps, of course, the graphics of the name is different, according to the number of layers to decide, the general double panel copying board is much simpler than the multi-layer board, multi-layer copying board is prone to misalignment, So the multilayer board copy board to be particularly careful and careful (the internal through hole and not through hole is prone to problems).

Double panel copying method:

1. Scan the upper and lower layers of the circuit board and save two BMP pictures.

2. Open the copy software QuickPC 2005, click “File” “Open base”, open a scan picture. Enlarge the screen with PAGEUP, see pad, place a pad according to PP, see the line according to PT line…… Just like a child drawing, draw it in the software and click “Save” to generate a B2P file.

3. Click “File” and “Open Base Map” to open the scan color map of another layer;

4. Click “File” and “Open” to open the previously saved B2P file. We can see that the newly copied board is superposed on this picture — the same PCB board with holes in the same position, but the circuit connections are different. So we press “Options” – “Layer Settings” to turn off the display top line and silk screen here, leaving only multiple layers of holes.

5. The hole on the top is in the same position as the hole on the bottom picture. Now we can trace the line on the bottom as we did in childhood. Click “Save” again – the B2P file now has the data at the top and bottom levels.

6. Click “file” “Export to PCB file”, you can get a PCB file with two layers of data, you can change the board or schematic diagram or directly send to PCB plate factory to produce multilayer board copying method:

In fact, the four board copy board is repeated copy two double panels, six is repeated copy three double panels…… The layers are daunting because we can’t see the wiring inside. A sophisticated multilayer board, how do we see its inner universe? – layered.

Now there are many ways to layer, there are potion corrosion, tool stripping, but it is easy to layer too much, loss of data. Experience tells us that sandpaper is the most accurate.

When we finish copying the top and bottom layer of PCB, we usually use sandpaper to grind off the surface layer and show the inner layer. Sandpaper is the ordinary sandpaper sold in the hardware store, usually laid on the PCB, and then hold the sandpaper, evenly rubbed on the PCB (if the board is small, also can be laid on the sandpaper, with one finger to hold the PCB on the sandpaper friction). The point is to smooth it so that it’s even.

Silk screen and green oil are generally wiped off, copper wire and copper skin should be wiped several times. Generally speaking, bluetooth board can be wiped in a few minutes, about ten minutes memory; Of course, with greater strength, it takes less time; Strength flower will have a little more time.

Mill plate is the most common plan used in stratification at present, but also the most economic. We can find a discarded PCB to try. In fact, it is not technically difficult to grind the board, but it is a bit boring. It takes some effort, and there is no need to worry about grinding the board to your fingers.

PCB diagram effect review

In the process of PCB layout, after the system layout is completed, the PCB diagram should be reviewed to see whether the system layout is reasonable and whether the optimal effect can be achieved. It can usually be examined from the following aspects:

1. Whether the system layout can ensure the reasonable or optimal wiring, whether it can ensure the reliable wiring, whether it can ensure the reliability of the circuit work. During the layout, you need to have an overall understanding and planning of the signal direction and the power and ground network.

2. Whether the size of the printed board is consistent with the size of the processing drawings, whether it meets the requirements of PCB manufacturing process, and whether there are behavioral marks. This point needs special attention, many PCB circuit layout and wiring are designed very beautiful, reasonable, but neglect the precise positioning of the positioning connector, resulting in the design of the circuit can not be connected with other circuits.

3. There is no 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. In the weld-free layout of the component, the height generally cannot exceed 3mm.

4. Component layout is dense and orderly, neatly arranged, whether all cloth. When laying out components, we should not only consider the direction and type of signals, and the areas that need attention or protection, but also consider the overall density of the device layout to achieve uniform density.

5. Can the components that need to be replaced frequently be easily replaced? Is it convenient for the plug-in board to be inserted into the equipment? It is necessary to ensure the convenience and reliability of replacing, connecting and inserting frequently changed components.