About pcb copy board, PCB cloning, PCB copy process introduction
About pcb copy board, PCB cloning, PCB copy process introduction
PCB copy board, the industry is often referred to as circuit board copy board, circuit board cloning, circuit board copying, PCB cloning, PCB reverse design or PCB reverse research and development. There are various opinions on the definition of PCB copy board in the industry and academia. , but they are not complete. If you want to give an accurate definition of PCB copy board, you can learn from the domestic authoritative PCB copy board laboratory: PCB copy board, that is, under the premise that there are already physical products and circuit boards. Reverse analysis of the circuit board by means of reverse R&D technology, and restore the original product PCB file, bill of materials (BOM) file, schematic file and other technical documents and PCB silk screen production files 1:1, and then use These technical documents and production documents are used for PCB board, component soldering, flying probe testing, circuit board debugging, and complete copying of the original circuit board template. Since the electronic products are all operated by the core control parts of various circuit boards, the process of extracting a complete set of technical data of any electronic product and copying and cloning the product can be completed by using a process such as PCB copy board.
For PCB copy board, many people do not understand, in the end what is PCB copy board, some people even think that PCB copy board is a cottage. In the understanding of everyone, the cottage is the meaning of imitation, but the PCB copy board is definitely not an imitation. The purpose of PCB copy board is to learn the latest electronic circuit design technology in foreign countries, and then absorb the excellent design scheme, and then use it to develop better design. The product.
PCB copy board is a reverse research technology that uses a series of reverse research techniques to obtain a PCB design circuit for an excellent electronic product, as well as a circuit schematic and a BOM. Through this reverse research method, a product that others need to develop in two or three years, we can learn from others in two or three years through the reverse research of PCB copy board. This has played a very important role in promoting the pursuit of the world by our developing countries. Moreover, the development of reverse research technology has also promoted the technological breakthroughs of those development teams. The vigorous development of reverse research technology has also led to the continuous updating of positive research techniques. Between positive research and reverse research is because of this competitive relationship, so the development of electronic technology in recent years can be changing with each passing day. Electronic products are updated almost once a year, and the speed of electronic product replacement will only increase. fast. Because PCB copy board reduces the threshold of electronic technology. PCB copying has enabled more and more developing countries to quickly embark on the forefront of high-tech electronic technology and research electronic technology with developed countries. The larger the research team, the more the world's electronic technology can develop.
Many people have misunderstood the concept of PCB copy board. In fact, with the continuous development and deepening of the copy board industry, today's PCB copy board concept has been extended to a wider extent, no longer limited to simple board copying and cloning. It will also involve the secondary development of products and the development of new products. For example, through the understanding and discussion of the analysis of existing product technical documents, design ideas, structural features, process technology, etc., it can provide feasibility analysis and competitive reference for R&D and design of new products, and assist R&D and design units to follow up in time. Technology development trends, timely adjustment and improvement of product design, research and development of the most competitive new products. At the same time, the process of PCB copying can realize the rapid update, upgrade and secondary development of various types of electronic products through the extraction and partial modification of technical data files. According to the document map and schematic diagram extracted by the copy board, professional designers can still The customer's willingness to optimize the design and modification of the PCB can also add new functions or redesign the functional features on the basis of this, so that products with new functions will appear at the fastest speed and a new attitude. Not only has its own intellectual property rights, but also won the first opportunity in the market, bringing double benefits to customers.
Technical realization process of PCB copy board
To put it simply, it is to first scan the board to be copied, record the detailed component position, then remove the components to make a bill of materials (BOM) and arrange material procurement, and the empty board scans into a picture. The process is restored to a pcb board image file, and then the PCB file is sent to the plate making factory board. After the board is made, the purchased components are soldered to the fabricated PCB board, and then the board is tested and debugged.
The specific technical steps are as follows:
The first step is to get a PCB. First, record the model, parameters, and position of all components on the paper, especially the direction of the diode, the transistor, and the direction of the IC notch. It is best to take a photo of two component locations with a digital camera. A lot of pcb boards are getting higher and higher. The above diodes are not noticed at all.
In the second step, all devices are removed and the tin in the PAD hole is removed. Clean the PCB with alcohol and put it into the scanner. When scanning, the scanner needs to slightly raise some scanned pixels to get a clearer image. Then polish the top and bottom layers slightly with water gauze, polish it to the copper film, put it into the scanner, start PHOTOSHOP, and scan the two layers separately by color. Note that the PCB must be placed horizontally and vertically in the scanner, otherwise the scanned image will not be used.
In the third step, adjust the contrast and brightness of the canvas so that the portion with the copper film and the portion without the copper film are strongly contrasted, then turn the secondary image to black and white to check whether the line is clear. If it is not clear, 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 that there is a problem with the graphics, you can use PHOTOSHOP to fix and correct it.
The fourth step is to convert the two BMP files into PROTEL format files, and transfer them into two layers in PROTEL. If the two layers of PAD and VIA are basically coincident, it indicates that the first few steps are very good. If there is a deviation, repeat the third step. Therefore, pcb copy board is a very patient work, because a small problem will affect the quality and the degree of matching after copying.
In the fifth step, the BMP of the TOP layer is converted into a TOP PCB. Note that the layer to be converted to the SILK layer is the yellow layer. Then you trace the line in the TOP layer and place the device according to the drawing in the second step. Remove the SILK layer after painting. Repeat until you have drawn all the layers.
In the sixth step, the TOP PCB and BOT PCB are transferred in PROTEL, and the combination is OK.
In the seventh step, use the laser printer to print TOP LAYER and BOTTOM LAYER on the transparencies (1:1 ratio), put the film on the PCB, and compare whether there is any error. If it is correct, you are done. .
A copy board like the original one was born, but it was only half done. Also test, test the electronic technology 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 multi-layer board, carefully polish it to the inner layer, and repeat the steps of the third to fifth steps. Of course, the naming of the graphics is different. According to the number of layers, the general double-panel copy board should be It is much simpler than a multi-layer board, and a multi-layer copy board is prone to misalignment, so the multi-layer board is particularly careful and careful (internal vias and non-vias are prone to problems).
Double panel copying method:
1. Scan the upper and lower layers of the board and save two BMP pictures.
2. Open the copy board software Quickpcb2005, click "File" to "Open Basemap" and open a scanned picture. Use PAGEUP to enlarge the screen, see the pad, press PP to place a pad, and see the line press PT.... Just like the child's drawing, draw it in this software and click "Save" to generate a B2P file.
3. Click "File" to "Open Basemap" to open another layer of scanned color map;
4. Click "File" to "Open" to open the previously saved B2P file. We see the newly copied board, which is stacked on top of this picture - the same PCB board, the holes are in the same position, but the line connections are different. . So we press "Options" - "Layer Settings", where the lines and silkscreens showing the top layer are turned off, leaving only a multi-layer via.
5. The top via is in the same position as the via on the bottom image, and the trace of the bottom layer is just like the trace when you were in childhood. Then click "Save" - the B2P file at this time has the top and bottom layers of data.
6. Click "File" to "Export as PCB File", you can get a PCB file with two layers of data, you can change the board or send out the schematic or directly to the PCB plate factory to produce
Multi-layer board copying method:
In fact, the four-layer board copy board is to duplicate two double-panel, the sixth layer is to repeatedly copy three double-panel... The reason why the multi-layer is daunting is because we can't see the internal wiring. A sophisticated multi-layer board, how do we see its inner layer?--layering.
There are many ways to solve the problem of stratification, such as chemical corrosion, knife peeling, etc., but it is easy to separate the layers and lose data. Experience tells us that sanding is the most accurate.
When we finish the top layer of the PCB, we usually use sandpaper to polish the surface layer to show the inner layer. The sandpaper is the ordinary sandpaper sold by the hardware store. Generally, the PCB is tiled, then the sandpaper is pressed and rubbed evenly on the PCB. (If the board is small, you can also flatten the sandpaper and use a finger to hold the PCB and rub it on the sandpaper). The point is to flatten out so that it can be evenly ground.
Silk screen and green oil are generally wiped off, copper wire and copper skin should be wiped a few times. In general, the Bluetooth board can be wiped in a few minutes, and the memory stick is about ten minutes; of course, the strength is great, the time spent will be less; the time for the effort will be a little more.
Grinding is the most common solution for stratification, and it is also the most economical. Let's try to find a piece of discarded PCB. In fact, there is no technical difficulty in grinding the plate. It is just a bit boring. It takes a little effort. You don't have to worry about grinding the plate to your fingers.
Reliability design of pcb copy board contact system
Proper selection of contact materials can improve the reliability and longevity of the relay IRF520NPBF. Different relays have different types of wear and wear due to the different load characteristics and disconnection capacities of the contact loops; these factors must be taken into account when designing contact and reed materials. The selected contact and reed materials should meet the following basic requirements:
1 has good electrical conductivity and thermal conductivity.
2 contacts and coating materials should be resistant to arcing or spark wear and mechanical wear, with a certain hardness and anti-adhesive properties.
3 Reed material should have good elasticity.
2) Requirements for contact contact form and shape size design:
1 For miniature, ultra-small and other small-loaded relays, the contacts should be in point contact form, pcb copy board to increase the pressure of the contact part and destroy the contaminants on the contact surface. For large load relays, the contacts should be in the form of surface contact to increase the heat dissipation area and reduce the electrical wear of the contacts.
In the form of 2 contact combinations, the assembly form should be avoided as much as possible, the unreliable factors caused by the assembly should be reduced, and the riveting can be replaced by reliable fusion welding.
3 Pairing with contacts of different materials to improve the arc resistance and wear resistance of the contacts.
4 Reed design quality should be small, the size should not be too long, such as the use of high elastic modulus materials, circuit board cloning to reduce the specific gravity of the material or improve the stiffness of the reed, so that its resonant frequency is higher than a given environmental frequency index, Thereby ensuring environmental adaptability of impact and vibration.
5 When passing the rated current, the current density of the reed must not exceed the specified value to ensure that the temperature rise of the reed does not exceed the allowable value, thus ensuring the reliability of the contact.
3) Design requirements for contact pressure and tracking:
1 Ensure that the electrical contact between the contacts is reliable and the contact resistance of the contacts is stable.
The tracking of the 2 contacts should be greater than the height of the contact wear during the specified life.
3 Appropriately select mechanical parameters such as contact pressure and tracking to minimize the number of jumps of the contacts and shorten the contact return time, thereby reducing the wear phase arc ablation of the contacts.
4 For small and medium-load relays, there should be some tracking between the contacts to clean the surface, reduce contact resistance and thermal effects, reduce faults, and improve contact reliability.