Coaxial Via Circuit Board Layout for Impedance Matching and EMI Shielding
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Solution Overview
Problem
Conventional circuit boards experience impedance mismatch and electromagnetic interference (EMI) shielding issues due to insulating layers in coaxial via designs, affecting high-frequency signal integrity and noise interference.
Innovation Solution
A circuit board design featuring multiple substrates with conductive structures and a conductive via structure that penetrates through dielectric layers, forming a signal path surrounded by a ground path to enhance impedance matching and EMI shielding, thereby improving signal integrity and reducing noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If insulating layers are added between inner conductor layer and outer conductor layer for isolation, then electromagnetic interference shielding is improved, but impedance mismatch occurs and signal integrity deteriorates
Solution Approach 1:
The patent removes the insulating layers from between the inner conductor layer and outer conductor layer in the coaxial via structure. By extracting these harmful insulating elements, the patent achieves both improved EMI shielding through alternative grounding methods and maintained impedance continuity for signal integrity, directly resolving the technical contradiction.
Solution Approach 2:
Instead of using insulating layers to achieve isolation (conventional approach), the patent inverts the approach by using conductive structures and grounding planes to achieve both isolation and impedance matching. The ground path surrounds the signal path conductively rather than insulatingly, resolving the contradiction between EMI shielding and signal integrity.
2Adaptability or versatility
If signal path and ground path ends are located on different planes, then routing flexibility is improved, but noise interference cannot be reduced
Solution Approach 1:
The patent transitions from planar separation of signal and ground paths to three-dimensional spatial arrangement. The ground path surrounds the signal path in a vertical/coaxial configuration rather than being separated on different horizontal planes, maintaining routing flexibility while providing continuous noise shielding through the surrounding geometry.
Data Source
AI summary
A circuit board includes a first substrate, a second substrate, a third substrate, a plurality of conductive structures and a conductive via structure. The second substrate is disposed between the first substrate and the third substrate. The third substrate has an opening and includes a first dielectric layer, a second dielectric layer, and a third dielectric layer. The opening penetrates the first dielectric layer and the second dielectric layer, and the third dielectric layer fully fills the opening. The conductive via structure penetrates the first substrate, the second substrate, the third dielectric layer of the third substrate, and is electrically connected to the first substrate and the third substrate to define a signal path. The first substrate, the second substrate, and the third substrate are electrically connected through the conductive structures to define a ground path, and the ground path surrounds the signal path.