In the PCB industry, what should I do if I have PCB files and want schematics? In PCB reverse technology research, reverse schematic diagram refers to deriving the PCB circuit diagram based on the PCB file diagram or directly depicting the PCB circuit diagram based on the actual product, aiming to explain the circuit board principle and working conditions. Moreover, this circuit diagram is also used to analyze the functional characteristics of the product itself. In forward design, general product development requires schematic design first, and then PCB design based on the schematic. What we are talking about is that if there are documents, sort out the schematic and then redesign the PCB.
1. Plan product functional areas
When reverse designing the schematic diagram of a complete PCB circuit board, reasonable division of functional areas can help engineers reduce unnecessary troubles and improve drawing efficiency. Generally speaking, components with the same functions on a PCB board will be arranged centrally. Dividing areas by function can provide a convenient and accurate basis for inferring the schematic diagram. However, this division of functional areas is not arbitrary. It requires engineers to have a certain understanding of electronic circuit related knowledge. First, find the core components in a certain functional unit, and then follow the wiring connections to find other components of the same functional unit to form a functional partition. The formation of functional partitions is the basis for schematic drawing. In addition, during this process, don’t forget to make clever use of the component serial numbers on the circuit board. They can help you partition functions faster.
2. The location of components must be determined
This benchmark part can also be said to be the main component used at the beginning of schematic drawing. After determining the benchmark parts, drawing based on the pins of these benchmark parts can ensure the accuracy of the schematic diagram to a greater extent.
For engineers, the determination of reference parts is not a very complicated matter. Generally, components that play a major role in the circuit can be selected as reference parts. They are generally larger in size and have more pins, making it easier to draw. Such as integrated circuits, transformers, transistors, etc., can be used as suitable reference components.
3. Reasonable drawing and wiring
For the distinction between ground wires, power wires, and signal wires, engineers also need to have relevant power supply knowledge, circuit connection knowledge, PCB wiring knowledge, etc. The distinction between these lines can be analyzed from the aspects of component connection, line copper foil width, and characteristics of the electronic product itself.
In wiring drawing, in order to avoid crossing and crossing of lines, a large number of grounding symbols can be used for ground wires. Different lines of different colors can be used to ensure clarity for various lines. Special signs can also be used for various components, and even Draw the unit circuits separately and finally combine them.
4. Master the basic framework and learn from similar schematics
Engineers need to be proficient in the framework composition and principle drawing methods of some basic electronic circuits. They must not only be able to directly draw the basic composition forms of some simple and classic unit circuits, but also be able to form the overall framework of electronic circuits.
On the other hand, don’t ignore that electronic products of the same type have certain similarities in schematic diagrams. Engineers can make full use of similar circuit diagrams to infer new product schematics based on accumulated experience.
5. Checking and Adjustment
After the schematic drawing is completed, the reverse design of the PCB schematic diagram is completed after testing and verification. The nominal values of components that are sensitive to PCB distribution parameters 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 completely consistent.
If the schematic layout is found to be inconsistent with the requirements during the verification, the schematic will be adjusted until it is completely reasonable, standardized, accurate and clear.