Rotated Signal Trace Routing for Magnetic Field Immunity
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Solution Overview
Problem
High-frequency magnetic fields penetrate metal shielding structures, making it challenging to prevent interference with magnetic field sensors, and increasing shield thickness is impractical and costly.
Innovation Solution
A substrate with multiple metal layers where signals are split and rotated across the layers, using conductive vias to couple traces, effectively cancelling the effects of magnetic fields on the signals, thereby enhancing immunity to magnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal shielding structures are used to prevent magnetic flux penetration, then shielding effectiveness against low-frequency magnetic fields is improved, but shielding effectiveness against high-frequency magnetic fields deteriorates
Solution Approach 1:
The patent segments the signal path into multiple traces across different metal layers. Instead of relying on a single shielding structure, the signal is divided and routed through multiple spatial paths (different layers and traces), which segment the exposure to magnetic flux and enable cancellation of induced effects.
Solution Approach 2:
The patent converts the harmful magnetic flux penetration into a beneficial cancellation effect. By routing multiple traces carrying the same signal through different spatial paths in a structured manner, the magnetic flux induces equal but opposite effects on different traces, which cancel each other out, transforming the harmful penetration into a protective mechanism.
2Reliability
If the thickness of metal shielding structure is increased to improve high-frequency shielding, then shielding effectiveness is improved, but material cost and space requirements worsen
Solution Approach 1:
The patent moves the shielding mechanism from the vertical dimension (increasing shield thickness) to the lateral dimension (routing traces across multiple metal layers and spatial paths). Instead of making the shield thicker in one dimension, the solution distributes signal paths across multiple layers and positions, achieving shielding through spatial arrangement rather than increased material thickness.
Solution Approach 2:
The patent changes the parameter of shielding from material thickness to trace arrangement geometry. By modifying how traces are routed across multiple layers and positions, the effective shielding parameter becomes the spatial configuration of signal paths rather than the physical thickness of metal shielding material.
3Device complexity
If signals are routed through single traces, then routing complexity is reduced, but immunity to magnetic field interference deteriorates
Solution Approach 1:
The patent segments each signal into multiple traces distributed across different metal layers. This segmentation increases magnetic field immunity because different traces experience different magnetic flux conditions, and the combined effect cancels out interference. The segmentation is managed through systematic routing patterns that balance complexity with performance.
Solution Approach 2:
The patent merges multiple traces carrying the same signal across different metal layers into a unified signal path. By combining the outputs of multiple traces that have been exposed to different magnetic conditions, the system achieves immunity while maintaining a coherent signal routing structure that manages complexity.
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 significantly reduces the likelihood of magnetic fields interfering with circuitry, improving the accuracy of magnetic field sensors by equally exposing signals to magnetic fields and minimizing unwanted interference.
Implementation Method 1
immunity to magnetic induction
Data Source
AI summary
A substrate includes at least first, second, and third metal layers and adjacent substrate portions having rotated arrangements of signal traces provided by the metal layers. Each metal layer includes first and second spaced portions. The first portion of the first metal layer includes a first trace configured to carry a first signal and the second portion of the first metal layer includes a second trace configured to carry a second signal. The first portion of the second metal layer includes third and fourth spaced traces configured to carry the second signal and the second portion includes fifth and sixth spaced traces configured to carry the first signal. The first portion of the third metal layer includes a seventh trace configured to carry the first signal and the second portion includes an eighth trace configured to carry the second signal.