Differential signal transmission multilayer PCB structure

Abstract

The invention discloses a differential signal transmission multi-layer PCB structure. The differential signal transmission multi-layer PCB structure comprises a plurality of PCBs arranged in a stacked mode, all the PCBs are oppositely attached and fixed, anti-pads with the same size are arranged at the corresponding positions of all the PCBs, the anti-pads are circular areas, and wiring is forbidden in the anti-pad areas; a pair of differential via holes are formed in each anti-pad area; the differential via holes of all the PCBs are arranged in a mutually aligned mode; signal conductors used for transmitting signals are evenly arranged on the inner walls of the differential via holes in the circumferential direction; the signal conductors are led out through differential transmission lines on signal layers for inputting and outputting signals; signals output from one signal layer is transmitted to the other signal layer through the differential transmission lines and the signal conductors; and conductive structures on the PCBs are insulated and isolated from the differential via holes by the anti-pads; According to the differential signal transmission multilayer PCB structure of the invention, the circular anti-pads are adopted to prevent the differential via holes from being short-circuited with a reference plane, the phenomenon of discontinuous impedance at the differential via holes is avoided, and the signal integrity of the differential via holes is effectively improved.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, and further relates to a differential signal transmission multilayer PCB board structure. Background technique [0002] The printed circuit board is referred to as PCB (Printed Circuit Board). The development of electronic technology and integrated circuit technology makes the circuit system more and more high-speed, integrated and precise, and the signal integrity requirements of the circuit system are also increasing. high. [0003] Compared with single-ended signals, differential signals have advantages in signal integrity such as strong anti-interference ability, effective suppression of electromagnetic interference, and accurate timing positioning. Differential signals are increasingly used in today's circuit system design. [0004] With the significant increase in signal rate and circuit system density, the routing density of PCB board-level design has also increased. Signal i...

AI Technical Summary

Problems solved by technology

At present, in actual engineering design, the design of the anti-pad shape of differential vias mostly adopts an elliptical or rectangular design, that is, connecting the circular anti-pads of two vias together to form an oval or rectangular anti-welding plate, Figure 1A and Figure 1B They are schematic diagrams of the structure of the existing technology using elliptical anti-pad and rectangular anti-pad respectively; the design of elliptical or rectangular anti-pad can meet the design requirements of most actual design projects, but with the significant increase in signal rate, engineering Design requirements for signal integrity characteristics of differential vias are getting higher and higher, and traditional differential via anti-pad structures can no longer meet the requirements

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