Magnetic Field Sensor Shield Structure for Stray Field Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic field sensor systems face challenges in accurately measuring magnetic fields due to stray magnetic fields along non-sensing axes, which affect sensitivity and linearity, leading to decreased detection quality.
Innovation Solution
The integration of magnetic field shields with specific geometric configurations around magnetic sense elements to suppress stray magnetic fields while maintaining minimal impact on the measurement magnetic field, allowing for independent adjustment of gain and suppression along sensing and non-sensing axes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic field shields are added to suppress stray magnetic fields, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines the magnetic field shield structure with the magnetic sense element into an integrated assembly. The shield is positioned around the sense element with specific geometric configurations (first and second shield portions with brim segments) that work together with the sense element to suppress stray magnetic fields while maintaining a compact, unified sensor structure.
Solution Approach 2:
The shield structure is designed with non-uniform geometric properties - the first and second shield portions have different configurations relative to the magnetic sense element. This local variation in shield geometry allows targeted suppression of stray magnetic fields from different directions while minimizing impact on the measurement magnetic field along the sensing axis.
2Reliability
If shield structures are used to suppress stray magnetic fields, then reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The shield structure is divided into discrete segments - a first shield portion and a second shield portion, each with specific brim segments. This segmentation allows the shield to be manufactured as separate components that can be assembled around the magnetic sense element, reducing the overall manufacturing precision requirements compared to a monolithic shield structure.
Solution Approach 2:
The shield portions are designed with brim segments that extend partially around the sense element rather than providing complete 360-degree coverage. This partial shielding approach achieves sufficient stray field suppression for the critical measurement directions while reducing the total shield material and manufacturing 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 solution effectively reduces the impact of stray magnetic fields, enhancing the accuracy and robustness of magnetic field measurements by maintaining sensitivity and preventing saturation effects in high measurement fields, thus improving the overall detection quality.
Implementation Method 1
A shield structure is formed on the substrate. The shield structure includes a first shield portion and a second shield portion, with the magnetic sense element disposed between the first and second shield portions
Implementation Method 2
A magnetic field sensor includes a magnetic sense element formed on a substrate. The magnetic sense element is configured to sense a measurement magnetic field along a sense axis
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A system comprises at least one magnetic field sensor having a magnetic sense element formed on a substrate. The sense element senses a magnetic field along a sense axis oriented in a first direction parallel to a surface of the substrate. A shield structure is formed on the substrate. The shield structure has first and second shield portions and the magnetic sense element is disposed between the shield portions. Each of the shield portions includes a body and first and second brim segments extending from opposing ends of the body. The body is aligned parallel to a second direction perpendicular to the first direction and parallel to the surface of the substrate. The brim segments are aligned substantially parallel to the first direction. The shield portions are arranged in mirror symmetry with the brim segments of each of the shield portions extending toward one another.