The reason why the expedited pcb circuit board adopts a serpentine position

Expedited pcb serpentine routing is to maintain the same delay of the same type of signal line. If you follow the straight line, the length is not the same, the frequency of the signal on the line is high, and the speed is fast, which may cause confusion when reading. Especially for the PCB board layout of the DRAM interface, this place where the interface signal synchronization is extremely high (G on the clock) needs to ensure that each line is the same length. Therefore, some wirings need to be deliberately lengthened even if they can be connected in a short place, so that the delay is consistent with other lines. The length and spacing of the lines are constrained, not arbitrary, so they are related to clock frequency, delay relationship, and even hardware device technology.

    The expedited pcb serpentine trace can be used for long wiring in a short space, so it saves area and has a certain inhibitory effect on electromagnetic interference (making full use of overlapping portions of the wiring to offset). Some are designed to prevent electromagnetic interference (EMI) and prevent parasitic interference. There are too many parallel lines that have a capacitive effect and cannot be brushed together. Circuit board wiring for high-frequency lines needs to be considered. It is important to consider how the current or voltage breakpoint needs to be handled. Isolating the high-frequency part, separating the high-frequency and low-frequency, inserting the power and ground lines, and avoiding the appearance of large loops in the wiring are some methods. It is also necessary to avoid sharp corners in the design, so the sharp corners must be made obtuse.

    In addition, when you make a straight turn, it will form a right angle. The low frequency does not matter. The high frequency is easy to cause reflection. It is important that the circuit board is easy to be lifted when it is processed at 90 degrees. It is especially easy to break.