Circuit board, connector assembly and cable harness

Abstract

A circuit board comprises at least a first wiring layer, a second wiring layer and a via. The first wiring layer is formed with a pair of first ends, a pair of second ends, a coupling portion, a pair of first trace portions and a pair of second trace portions. The coupling portion has a pair of first coupling points, a pair of second coupling points, an inner trace portion, an outer trace portion and a ground conductor portion. The inner trace portion has a length equal to a length of the outer trace portion. The ground conductor portion is arranged between the inner trace portion and the outer trace portion. The second wiring layer is formed with a ground pattern. The ground conductor portion is connected with the ground pattern through the via.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is based on and claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. JP2017-247425 filed Dec. 25, 2017, the contents of which are incorporated herein in their entireties by reference.BACKGROUND OF THE INVENTION[0002]This invention relates to a circuit board, a connector assembly and a cable harness.[0003]Referring to FIG. 7, JP-A 2004-14800 (Patent Document 1) discloses a circuit board 900 on which a pair of differential traces 920 is formed. The differential traces 920 have a pair of first trace portions 921, a pair of second trace portions 928 and a coupling portion 930. The first trace portions 921, the coupling portion 930 and the second trace portions 928 are coupled in this order. The coupling portion 930 has a pair of first coupling portions 932, a pair of third trace portions 933, a pair of through holes 934, a pair of fourth trace portions 936 and a pair of second coupling portions 937. The co...

AI Technical Summary

Benefits of technology

The present invention provides a circuit board that reduces skew (when signals are distorted) and minimizes deterioration of differential to common-mode conversion. This is achieved by preventing electrical interaction between differential traces at a bending region where distortion might occur. The circuit board has differential traces with equal lengths, which reduces skew. Additionally, a ground conductor portion is arranged between the inner and outer trace portions to prevent electrical interaction and minimize deterioration of differential to common-mode conversion. The circuit board design reduces skew occurrence and improves differential to common-mode conversion.

Problems solved by technology

Accordingly, the cable harness having this structure is unfavorable.

Accordingly, skew occurs between a differential signal pair which passes through the modified differential traces, and thereby a transmission error occurs.

However, the remodeled shape of the inner trace distorts differential signals to cause unnecessary mode conversion where some of differential-mode signals are converted to common-mode signals.

Specifically, the remodeled differential traces have a drawback to cause differential to common-mode conversion.

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