Multilayer Substrate Ground Conductor Openings for Impedance Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multilayer substrates with independent ground conductors for each transmission line face issues with impedance fluctuations due to lamination misalignment and crosstalk between signal lines, which affect the isolation and characteristic impedance of transmission lines.
Innovation Solution
The multilayer substrate configuration includes interlayer connection conductors and strategically positioned openings in the ground conductors that do not overlap with signal lines, ensuring stable impedance and reduced crosstalk by radiating electromagnetic waves and maintaining isolation between transmission lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If openings are formed in the auxiliary ground conductor to adjust transmission line impedance, then impedance can be tuned, but impedance fluctuates greatly when lamination misalignment occurs
Solution Approach 1:
The patent introduces an auxiliary ground conductor as an intermediary element between the signal line and the main ground conductor. This auxiliary ground conductor with strategically placed openings serves as a mediator to adjust impedance while the main ground conductor provides stable reference potential, thus resolving the contradiction between impedance tunability and stability
Solution Approach 2:
The ground conductor system is segmented into a main ground conductor and an auxiliary ground conductor with openings. The auxiliary ground conductor is further segmented into multiple discrete opening regions. This segmentation allows localized impedance adjustment through the openings while the continuous main ground conductor maintains overall stability and reference potential
2Reliability
If independent ground conductors are provided for each transmission line, then isolation between transmission lines is ensured, but device complexity increases
Solution Approach 1:
The patent merges multiple ground conductor functions into a unified ground conductor structure that serves multiple transmission lines. The auxiliary ground conductor with openings provides impedance adjustment for signal lines while the continuous main ground conductor provides reference potential for multiple transmission lines simultaneously, reducing the number of separate ground conductors needed
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively reduces impedance fluctuations and crosstalk, maintaining consistent characteristic impedance and improving isolation between transmission lines, even with lamination misalignment, and enhances the mechanical strength and reliability of the multilayer substrate.
Implementation Method 1
the first ground conductor includes a first opening and a second opening, and the second ground conductor includes a third opening and a fourth opening... the first opening and the third opening extend continuously along the parallel extending portions... to radiating electromagnetic waves and maintaining isolation between transmission lines
Data Source
AI summary
A multilayer substrate includes a laminate, first and second signal lines, first and second ground conductors, and interlayer connection conductors. The first and second signal lines extend along a transmission direction and include parallel extending portions that extend in parallel or substantially in parallel with each other. The first and second ground conductors sandwich the first and second signal lines in a laminating direction. The first and second ground conductors respectively include a first opening and a third opening between the signal lines when viewed from the laminating direction, and respectively include second openings and fourth openings disposed outside in a width direction orthogonal or substantially orthogonal to the transmission direction in the parallel extending portions when viewed from the laminating direction. The interlayer connection conductors are disposed in the transmission direction and at least between the signal lines.