Strong radiation signal lines (high frequency, high speed, especially the clock line) should not be close to the interface, handle bars, etc. to prevent external radiation. Sensitive signal (mainly refers to: weak signal, reset signal, input signal of comparator, reference power supply of AD, phase-locked loop filter signal, filter part of PLL circuit inside the chip.) The wiring should be as short as possible, not close to strong radiation signals , not on the edge of the board, more than 15mm away from the outer metal frame. For long-distance wiring, you can wrap the ground (it should be noted that the ground wrapping may cause impedance changes), and the inner layer is routed. In addition, for the traces of chips with weak ESD, inner layer traces are recommended, which can reduce the probability of chip damage.