PCB Spread Weave Skew Minimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed signal routing on printed circuit boards (PCBs) is restricted to uniform directions due to narrow connector channels, leading to skew caused by differences in dielectric permittivity between differential signal traces, which affects signal integrity and propagation.
Innovation Solution
The method involves determining the weft direction of a PCB with a spread weave and designing differential pairs to be routed within a fixed region in this direction, minimizing skew by aligning the routing design with the weft direction to equalize dielectric permittivity and impedance between traces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If differential pairs are routed in narrow connector channels with fixed directions, then routing constraints are satisfied, but signal skew increases due to unequal dielectric permittivity
Solution Approach 1:
The patent applies local quality by making the dielectric structure different in the warp and weft directions through spread glass weave orientation. The glass fibers are deliberately spread more in one direction to create direction-dependent dielectric properties, allowing the differential pairs routed in the weft direction to experience more uniform dielectric permittivity and reduced skew, while accepting that warp direction routing would have different characteristics.
2Reliability
If spread glass weave is used to enhance signal integrity, then dielectric uniformity improves, but manufacturing complexity increases
Solution Approach 1:
The patent changes the physical parameters of the glass weave structure by controlling the spread orientation and density of glass fibers during PCB manufacturing. By adjusting the weave pattern parameters (spread ratio, fiber orientation angle, fiber density), the dielectric properties can be optimized for signal integrity while maintaining compatibility with standard PCB manufacturing processes.
Data Source
AI summary
A method of manufacturing a printed circuit board (PCB) includes determining a weft direction of the PCB, and defining a routing design of differential pairs. The routing design is designed to have a fixed region in the weft direction. The method further includes manufacturing the PCB according to the routing design.