Laminated PCB Through-Hole Structure for Impedance-Matched Signal Paths
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing circuit boards experience impedance mismatch and electromagnetic interference (EMI) shielding gaps due to the design of coaxial via, which affects signal integrity and noise reduction, especially at high-frequency signals.
Innovation Solution
A circuit board design featuring a conductive through hole structure with conductive pillars and dielectric layers that electrically connect external circuit layers, forming a signal path surrounded by a ground path to enhance signal integrity and reduce noise interference, using a manufacturing method that involves lamination and patterning of metal and conductive layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If insulating layers are laminated between inner conductive layer and external conductive layer for coaxial via blocking, then EMI shielding is achieved, but impedance mismatch occurs and signal integrity deteriorates
Solution Approach 1:
The patent removes the traditional insulating layer structure from the coaxial via design. Instead of using laminated insulating layers between conductive layers, the invention uses a solid core structure that provides both EMI shielding and impedance matching simultaneously, eliminating the source of the contradiction.
Solution Approach 2:
The patent employs composite material structures where a solid core (which may be conductive or semi-conductive) is combined with dielectric materials in a specific configuration. This composite structure achieves both EMI shielding through the core and proper impedance matching through the surrounding dielectric layers, resolving the contradiction between shielding and signal integrity.
2Adaptability or versatility
If two ends of signal path and two ends of ground path are located on different planes, then routing flexibility is improved, but noise interference increases and signal loop is not closed
Solution Approach 1:
The patent utilizes the vertical dimension (through-hole routing) to connect signal and ground paths between different planes. By creating closed loops through the thickness of the PCB using via structures, the invention maintains routing flexibility across planes while simultaneously closing the signal loops to minimize noise interference and improve signal integrity.
3Ease of manufacture
If conventional build-up method with insulating layers is used for coaxial via, then manufacturing simplicity is maintained, but signal energy loss increases due to impedance mismatch
Solution Approach 1:
The patent changes the key parameter of the via structure from an insulating-layer-based design to a solid-core-based design. This parameter change fundamentally alters the electromagnetic characteristics of the via, achieving proper impedance matching and reducing signal energy loss while maintaining compatibility with standard manufacturing processes.
Data Source
AI summary
A circuit board includes a first external circuit layer, a first substrate, a second substrate, a third substrate, and a conductive through hole structure. The first substrate includes conductive pillars electrically connecting the first external circuit layer and the second substrate. The second substrate has an opening and includes a first dielectric layer. The opening penetrates the second substrate, and the first dielectric layer fills the opening. The third substrate includes an insulating layer, a second external circuit layer, and conductive holes. A conductive material layer of the conductive through hole structure covers an inner wall of a through hole and electrically connects the first and the second external circuit layers to define a signal path. The first external circuit layer, the conductive pillars, the second substrate, the conductive holes and the second external circuit layer are electrically connected to define a ground path surrounding the signal path.