Differential Wiring Pattern Structure for Impedance Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed differential transmission paths for DVI or HDMI standards face challenges in achieving uniform characteristic impedance and equal wiring lengths, leading to increased patterning area requirements and signal reflection due to the placement of electrostatic protection elements.
Innovation Solution
A wiring pattern structure where first and second signal lines form parallelogram-shaped areas with overlapping electrostatic protection elements, reducing line-to-line coupling and maintaining uniform impedance by adjusting the distance and width of signal lines, and using varistors as electrostatic protection elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrostatic protection elements are provided in differential transmission paths, then integrated circuit elements are protected from surge voltages, but the characteristic impedance of the transmission path becomes non-uniform
Solution Approach 1:
The patent applies local quality by making the signal lines have different widths in different sections. Specifically, the signal lines have a first width in sections without electrostatic protection elements and a second width (narrower than the first width) in sections with electrostatic protection elements. This local variation in line width compensates for the impedance change caused by the electrostatic protection elements, maintaining uniform characteristic impedance across the entire transmission path while preserving surge protection functionality.
2Manufacturing precision
If signal lines are separated to reduce line-to-line coupling in areas with electrostatic protection elements, then characteristic impedance uniformity is improved, but the patterning area increases
Solution Approach 1:
The patent applies parameter changes by varying the width parameter of the signal lines along their length. Instead of changing the physical separation distance between lines, the invention changes the width parameter of the lines themselves - narrower in sections with electrostatic protection elements and wider in sections without. This parameter variation achieves impedance uniformity while maintaining compact signal line spacing and minimizing the overall patterning area.
3Speed
If multiple differential transmission paths are provided for DVI or HDMI standards, then high-speed signal transmission is enabled, but it becomes difficult to achieve equal wiring lengths for all paths
Solution Approach 1:
The patent applies local quality by providing different width sections at different locations along the signal lines. By strategically placing narrower width sections in specific areas, the patent compensates for path length differences between multiple differential transmission paths. This allows outer paths and inner paths to have equal effective electrical length despite physical routing differences, enabling synchronized high-speed signal transmission across all paths.
Data Source
AI summary
A wiring pattern structure having differential transmission paths electrically connects an integrated circuit element and a connector, which are arranged on a printed wiring board. Each of the differential transmission paths includes a pair of first and second signal lines. The first and second signal lines are substantially hook-shaped and a substantially rectangular area is formed between the first and second signal lines. First and second electrostatic protection elements are disposed in the substantially rectangular area. A bent portion of each of the first and second signal lines may be rounded.