In the PCB reverse technology research, the backstepping schematic refers to the PCB file diagram based on the introduction or directly described in accordance with the product PCB circuit diagram, designed to illustrate the principles and work of the circuit board. Also, the circuit diagram is used to analyze the functional features of the product itself. In the forward design, the general product development should be designed by principle diagram, and then the PCB is designed according to the schematic diagram.

Whether it is used to analyze circuit board principles and product work characteristics in reverse studies, or to be used as the basis and basis for PCB design in forward design, the PCB schematic diagram has a special function. Then, how do you deduce the PCB schematic diagram according to the file diagram or physical object, and should we pay attention to the details of the reverse process?

First, rational division of functional areas
In the reverse design of the schematic diagram of a well designed PCB circuit board, the rational division of functional areas can help engineers reduce unnecessary troubles and improve the efficiency of rendering. Generally speaking, the components with the same function on a PCB board will be centrally arranged, and the area divided by function can be conveniently and accurately based on the backstepping schematic.
However, the division of the functional areas is not arbitrary. It requires engineers to have a good understanding of electronic circuit knowledge. First of all, find out the core element of one of the functional units, then according to the line connecting the other components can be found with a functional unit will take, form a partition function. The formation of functional partitions is the basis of schematic drawing. In addition, don't forget to take advantage of the component numbers on the circuit board, which can help you perform functional zoning faster.

Second, correctly distinguish the line, draw wiring reasonably
For the ground wire, power line, signal line differentiation, also need engineers have relevant power knowledge, circuit connection knowledge, PCB wiring knowledge, and so on. These lines can be analyzed from the connection of components, the width of copper wires, and the characteristics of electronic products.
In order to avoid wiring drawing, line crossing and thrust, and can be used in large amounts of symbol grounding wire, different lines of various lines can use different colors to ensure clear, components can also use special signs of all kinds, can even separate unit circuit drawing, and finally combined.

Third, find the benchmark
This standard can also be said to be the main components of principle drawing at the beginning with, after determining the reference element, drawing according to these datum pins, to ensure accuracy of the principle diagram to a greater extent.
For engineers, the benchmark is not very complicated, in general, can choose to play a major role in the circuit components as a benchmark, they are generally larger and more convenient for the pin, drawing, such as integrated circuit, transformer, transistors and so on, can be used as a suitable benchmark.

Fourth, grasp the basic framework, draw lessons from similar principles
Some of the basic framework for electronic circuit structure and principle of drawing, engineers need to master, not only to the basic form of some simple and classic circuit for direct rendering, but also can form the overall framework of electronic circuit.
On the other hand, don't ignore the electronic products of the same type are similar in principle, engineers can according to the accumulation of experience, make full use of the similar circuit diagram for the product of the new principle of backstepping.

Fifth, check and optimize
After the completion of the schematic drawing, but also through the test and check links, we can say that the reverse design of the PCB schematic is finished. The nominal values of the components which are sensitive to the parameters of the PCB distribution need to be checked and optimized. According to the PCB file diagram, the schematic diagram is compared, analyzed and checked to ensure that the schematic diagram and the file diagram are in complete agreement.