Wiring Board Ground-Wiring Segmentation for High-Speed Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wiring boards experience significant impedance mismatch and transmission loss during high-speed signal transmission due to large areas where differential signal wirings face ground layers, hindering optimal high-speed transmission characteristics.
Innovation Solution
A wiring board design featuring a first conductor layer with differential signal wirings and a second conductor layer with ground wirings arranged to avoid overlap and intersecting connections, ensuring minimal area exposure of differential signal wirings to ground layers, thereby reducing impedance mismatch and transmission loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ground wirings are arranged to intersect between signal wirings to provide adequate grounding area, then grounding coverage is improved, but impedance mismatch and transmission loss increase
Solution Approach 1:
The ground wiring is segmented into multiple separate ground wirings rather than using a continuous ground layer. These segmented ground wirings are positioned at specific locations to provide adequate grounding coverage while avoiding direct intersection with signal wirings, thereby reducing impedance mismatch and transmission loss.
Solution Approach 2:
Ground wirings are strategically positioned at specific locations rather than uniformly distributed. The ground wirings are placed at locations where they provide effective grounding without creating large overlapping areas with signal wirings, thus achieving local optimization of both grounding coverage and signal transmission quality.
2Reliability
If ground layer area facing differential signal wirings is increased, then grounding effectiveness is improved, but impedance control becomes difficult
Solution Approach 1:
The continuous ground layer is segmented into discrete ground wirings positioned at specific locations. This segmentation allows precise control over the ground wiring positions relative to signal wirings, enabling accurate impedance control while maintaining grounding effectiveness through strategic placement of individual ground wiring segments.
3Object-affected harmful factors
If ground wirings are positioned close to signal wirings for shielding, then electromagnetic interference is reduced, but manufacturing complexity increases
Solution Approach 1:
The ground shielding is implemented through segmented ground wirings positioned adjacent to signal wirings rather than a continuous ground layer. This segmentation simplifies the manufacturing process by allowing individual ground wirings to be positioned and adjusted independently, reducing the overall manufacturing complexity while maintaining effective electromagnetic interference shielding.
Data Source
AI summary
A wiring board includes: a first conductor layer; a second conductor layer formed so as to face the first conductor layer; a plurality of differential signal wirings, each of which includes a pair of signal wirings, formed in the first conductor layer; and a plurality of first ground wirings formed in the second conductor layer and arranged along and not overlapping the pairs of signal wirings in a plan view viewed in a facing direction in which the first conductor layer and the second conductor layer face each other; and a plurality of second ground wirings formed in the second conductor layer with spacings so as to intersect the first ground wirings and to connect the two first ground wirings adjacent to each other.