Printed circuit boards

Abstract

The disclosed PCB comprises: at least one signal layer with at least one isolative grounding line and two near signal lines, and a grounding layer. Wherein, the isolative grounding line contains some through-holes connected with the grounding layer, and the distance of two near holes enables the EM wave resonant frequency over the highest frequency of signal in the signal line. This invention can inhibit the line interference efficiently.

Description

【Technical field】 [0001] The invention relates to a printed circuit board, in particular to a printed circuit board with isolated ground wires. 【Background technique】 [0002] At present, when designing printed circuit board layout, noise interference or coupling interference between two adjacent signal lines is usually considered. Therefore, electronic engineers have designed many methods to suppress interference for such problems. Among them, setting an isolated ground line between two adjacent signal lines is a method to suppress mutual interference between signal lines. [0003] Please refer to FIG. 1, which is a partial wiring diagram of a signal layer 10' of a printed circuit board, wherein an isolated grounding line 12' is provided between two adjacent high-speed signal lines 14', which is used to reduce the voltage of the two high-speed signal lines 14. ', the isolated ground line 12' is also provided with a number of via holes 122', and is connected to the ground l...

AI Technical Summary

Problems solved by technology

[0004] Since the vias 122' are all connected to the ground plane with zero potential, according to electromagnetic theory, the distance between two consecutive electric fields equal to zero is half an electromagnetic wave wavelength, so the distance between two adjacent vias 122' is equal to the isolation The resonant half-wavelength of the electromagnetic wave on the ground wire 12', and the placement position of the via hole 122' on the isolated ground wire 12' is generally not designed, or even randomly placed, so when the isolated ground wire When the distance between two adjacent via holes 122' on the isolation ground line 12' makes the resonant frequency of the electromagnetic wave on the isolated ground line 12' just equal to the operating frequency of the signal on the high-speed signal line 14', the high-speed signal line 14' The noise generated by the signal will be easily coupled to other adjacent signal lines through the isolated ground line 12', so that the isolated ground line 12' will not reduce the interference between the two signal lines 14' effect, but will cause greater noise interference

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