PCB wiring is very important, and has a great impact on product life, stability, and electromagnetic compatibility. If the circuit board wiring is unreasonable, product performance will be greatly reduced. Here are some special methods of pcb prototype manufacturer circuit board wiring, I hope it will be helpful to you.
1. Right-angle routing:
The influence of right-angle routing on the signal is mainly reflected in:
(1) The corner can be equivalent to the capacitive load on the transmission line, which slows down the rise time;
(2) Impedance discontinuity will cause signal reflection;
(3) The EMI generated by the right-angle tip will become the focus of high-speed circuit design in the field of RF design above 10GHz.
2. Differential wiring
Compared with ordinary single-ended signal routing, the advantages of differential signal are as follows:
(1) Strong anti-interference ability. Because the coupling between the two differential traces is very good, when there is noise interference from the outside, they are almost coupled to the two lines at the same time.
(2) It can effectively suppress EMI. Since the polarities of the two signals are opposite, the electromagnetic fields radiated to the outside can cancel each other, and the tighter the coupling, the less electromagnetic energy leaked to the outside world.
(3) Accurate timing positioning. Since the switching change of the differential signal is located at the intersection of the two signals, unlike ordinary single-ended signals, which rely on the high and low threshold voltages to determine, it is less affected by the process and temperature, which can reduce the error in the timing, and it is also more suitable for low Circuit of amplitude signal.
3. Serpentine line
Snake line is a type of routing method often used in Layout. Its main purpose is to adjust the delay to meet the system timing design requirements. The two most critical parameters are the parallel coupling length (Lp) and the coupling distance (S).
The above are several special wiring methods for SMT PCB circuit boards introduced by PCB engineers. Have you mastered them?