There is a defined process through which PCB reverse engineering works such as scanning a picture of the circuit board, removing the components, making BOM, grinding the plate, adjusting the contrast and shade, starting the PCB reverse engineering software Protel, converting the BMP of the top layer into TOP, Convert the BMP of the BOT layer into BOT, Compose it into a graph, Print double-sided PCB board.
PCB reverse engineering is a complicated process to perform. Though it is basically dealing with very tiny components, the tools used for this process are very sophisticated. Below are a few of the various PCB reverse engineering tools used in this process given
Impedance test, power supply current supply, electronic component model, test circuit board circuit. a DC power supply, a magnifying glass, a circuit detector, and an impedance tester, among others.
Polishing PCB board tools:
Mainly PCB board polishing primarily comprising sandpaper, grinding equipment, impellers, and corrosive agents.
Scan THE PCB and save the circuit diagram as a collection of images for later board duplication. Scanner, computer, printer, and caliper are the main tools.
Engineers frequently have trouble locating the drawings while repairing electronics products, especially older models. There might no longer be any circuit diagrams available at present. Drawing a circuit diagram based on the actual products is therefore required in order to analyze and improve the product. There are different processes used to execute this process few of which are given below.
1. Reasonably divide functional areas
When reverse designing the schematic diagram of an intact PCB board. Dividing up functional areas can help engineers avoid unnecessary problems. It also improves the efficiency of drawing.
In general, the same functional components on an electronic circuit board will be placed centrally. Dividing areas by function can provide a convenient and accurate basis for reverse analysis of schematics. However, the division of this functional area is not arbitrary. It requires engineers to have a certain understanding of electronic circuit related knowledge.
First, find out the core components of a functional unit, and then find out the same function according to the wiring connection， Other elements of the unit. Form a functional partition (the formation of functional partition is the basis of schematic drawing). In addition, In this process, don’t forget to use the component number on the circuit board wisely, they can help you to partition the function faster.
2. Find the right reference components
This reference component can also be said to be the main component for reference at the beginning of schematic drawing. In determining the benchmark , The components are then drawn according to the pins of these reference components. The accuracy of schematic diagram can be guaranteed to a greater extent. For engineers, the determination of reference components is not very complicated, in general, can choose to be the main circuit. The components to be used as reference components, they are generally larger, more pins, easy to draw, such as integrated circuits, transistors and so on. Can be used as appropriate reference components.
3. Correctly distinguish lines and reasonably draw wiring
To distinguish ground cables, power cables, and signal cables, engineers also need to have knowledge of power supplies, circuit connections, PCB wiring knowledge and so on. The distinction of these circuits can be analyzed from the connection of components, the width of copper foil and the characteristics of electronic products themselves. In cabling drawing, in order to avoid line crossing and interspersing, ground symbols can be widely used for ground cables. Various lines can use different colors of different lines to ensure clear discernable, various components can also use special signs, and even the unit circuit can be drawn separately, and then combined.
4. Master the basic framework and refer to similar schematic diagrams
For some basic electronic circuit frame composition and principle drawing method, engineers need to master, not only to be able to some Simple, classic basic composition of the unit circuit to draw directly, but also to form the overall framework of the electronic circuit. On the other hand, do not neglect that the same type of electronic products have certain similarities in the schematic diagram. Engineers can according to the accumulation of experience, full reference to similar circuit diagram to carry out the reverse analysis of the new product schematic diagram.
5. Check and optimize
After schematic drawing is completed, testing and verification should be carried out. To calculate the PCB schematic of the reverse design end. The marking values of components sensitive to PCB distribution parameters need to be checked and optimized, And the schematic diagram should be carried out according to the PCB file diagram Contrastive analysis and check to ensure that the schematic diagram, And document diagram are completely consistent.
PCB design documents are converted to PDF files during PCB reverse engineering analysis for simple viewing or to query related component data. There are steps to steps processes for using Altium Designer to produce a standard PDF file for getting a printed circuit board reverse engineering.
During PCB reverse engineering analysis, PCB design documents are converted to PDF files for easy viewing or for querying related component information. The following describes how to output a regular PDF file by Altium Designer.
The preliminary work is to install the virtual printer and PDF reader on the computer. After you are ready, follow the following steps:
(1) Run the File-Intelligent PDF command to open the PDF output configuration wizard, as shown in Figure 11-25. Press Next to go to the Next step.
(2) Select the export target: Set the output path of the file as prompted.
(3) Export BOM of raw materials: BOM output option, this option is optional, but Altium Designer has a special BOM output function, this is generally not checked.
Double click “Top Layer Assembly Drawing” output column, you can set the output properties, Assembly elements generally output mechanical Layer, screen printing Layer and welding resistance Layer, click “Add” “Delete” and other buttons to add, delete and other operations related to the output Layer. Similarly, do the same for the output bar of “Bottom Layer Assembly Drawing”.
If it is an assembly drawing, generally add the following line layer for output.
1, Top/Bottom Overlay:
2, Solder: Top/Bottom Solder.
3, Mechanical/ keep-out Layer.