Magnetic Conductor Via Shielding for EMI Reduction
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Solution Overview
Problem
High-density circuit board layouts with multi-layer boards experience electromagnetic interference due to vias, leading to signal quality issues, and conventional methods like reducing via size and using anti-pads increase manufacturing costs and risk of board damage.
Innovation Solution
An anti-electromagnetic interference circuit board is designed with a magnetic conductor, such as a sprayed wave-absorbing magnetic conductor, covering some vias to reduce electromagnetic waves and improve signal quality, with adjustable positioning and combination of magnetic materials like iron, cobalt, nickel, or their alloys to enhance magnetic loss effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If via size is reduced and anti-pads are used to avoid capacitive and inductive effects, then electromagnetic interference is reduced, but manufacturing costs increase due to blind hole and buried hole fabrication
Solution Approach 1:
The patent extracts the electromagnetic shielding function from the via structure itself and places it on the circuit board surface through magnetic conductors. This separates the signal transmission function (via) from the electromagnetic shielding function (magnetic conductor), allowing standard via fabrication without expensive blind/buried hole processes while still achieving EMI reduction.
Solution Approach 2:
The magnetic conductor acts as an intermediary element placed between the via and the external environment. It absorbs and redirects electromagnetic radiation without requiring modification to the via structure itself, serving as a cost-effective mediator that solves the EMI problem without the high manufacturing costs of blind/buried holes.
2Object-affected harmful factors
If circuit board thickness is reduced to minimize radiation, then electromagnetic interference is reduced, but the board becomes prone to bending and damage
Solution Approach 1:
Instead of reducing thickness in the vertical dimension to minimize radiation, the patent introduces electromagnetic shielding in the horizontal dimension by placing magnetic conductors on the circuit board surface. This dimensional shift allows maintaining adequate board thickness for mechanical strength while achieving EMI reduction through surface-level magnetic shielding.
3Area of stationary object
If multi-layer boards are used to increase wiring area, then circuit density is improved, but electromagnetic interference between layers increases
Solution Approach 1:
The magnetic conductors are placed directly on the circuit board surface at locations corresponding to via positions, creating a self-service shielding system. The shielding elements automatically counteract the electromagnetic radiation generated by the multi-layer via structures, allowing the multi-layer board to maintain its high wiring area advantage while eliminating inter-layer EMI through localized surface-mounted magnetic shielding.
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
The solution effectively reduces radiated noise and improves electromagnetic compatibility, preventing high-speed signal crosstalk and enhancing signal transmission quality while maintaining cost-effectiveness and board integrity.
Implementation Method 1
various magnetic material are used in combination on the circuit board to reduce electromagnetic waves and improve quality of signal transmission
Data Source
AI summary
An anti-electromagnetic interference circuit board includes a circuit board and a magnetic conductor. The circuit board has a plurality of vias, and the magnetic conductor is covered on the circuit board to cover some of the vias. The magnetic conductor includes a plate, a carrier, a sprayed magnetic conductor, and a wave absorbing magnetic conductor.