Tri-Axial Magnetic Field Sensing Using Inclined Magnetoresistance Bridges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional magnetic field sensing technologies for portable devices require complex manufacturing processes and multiple wafers to achieve tri-axial sensing, leading to increased size and cost, with sensitivity differences between axes causing confusion when the device is rotated.
Innovation Solution
A magnetic field sensing apparatus with a simplified structure and smaller size, utilizing a substrate with inclined surfaces and switching circuit to connect magnetoresistance sensors forming Wheatstone bridges, allowing for tri-axial sensing with fewer sensors and a more efficient framework.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If composite sensing elements (GMR/TMR multilayer film structure and Hall element) are used to accomplish tri-axial sensing, then tri-axial sensing capability is achieved, but sensing precision becomes inconsistent across different axes due to different sensing sensitivities
Solution Approach 1:
The patent uses three identical magnetoresistance sensing units with the same structure and sensing mechanism, ensuring homogeneous sensing characteristics across all three axes. This eliminates the precision inconsistency problem that occurs when mixing different sensing element types (GMR/TMR and Hall elements) as mentioned in the background art.
2Adaptability or versatility
If two or more wafers are used to manufacture multi-axial magnetic field sensing module, then multi-axial sensing is achieved, but manufacturing complexity increases and cost rises
Solution Approach 1:
The patent integrates three magnetoresistance sensing units and switching circuits onto a single wafer, merging multiple sensing functions into one integrated structure. This eliminates the need for multiple separate wafers and complex assembly processes, directly reducing manufacturing complexity and cost while maintaining tri-axial sensing capability.
Solution Approach 2:
The sensing units are designed with multi-functionality, where each unit can sense magnetic fields in different orientations depending on its inclination angle. The switching circuit enables these units to be configured for different sensing axes, allowing a single wafer to perform multi-axial sensing that previously required multiple specialized wafers.
3Adaptability or versatility
If two or more wafers are used to manufacture multi-axial magnetic field sensing module, then multi-axial sensing is achieved, but device size increases
Solution Approach 1:
By merging three sensing units and switching circuits onto a single wafer, the patent dramatically reduces the overall device volume compared to using multiple separate wafers. The integrated layout allows compact arrangement of all sensing elements and interconnections within a single substrate, minimizing the module's physical footprint.
Solution Approach 2:
The patent employs a nested arrangement where three magnetoresistance sensing units are positioned at different inclination angles on the same wafer substrate. This nesting approach allows multiple sensing functions to coexist in a compact, space-efficient manner, with each unit utilizing the same physical substrate rather than requiring separate volumetric space.
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
Enables accurate tri-axial magnetic field sensing with a reduced number of sensors, simplifying the framework and minimizing size, while maintaining sensitivity across different axes, thus addressing the complexity and cost issues of conventional methods.
Implementation Method 1
The first magnetic field sensing unit includes a plurality of magnetoresistance sensors connected to form a Wheatstone full bridge and disposed on the surface and is configured to sense a magnetic field component in a first direction
Implementation Method 2
a plurality of magnetoresistance sensors connected to form a Wheatstone full bridge
Data Source
AI summary
A magnetic field sensing apparatus including a substrate, first, second, and third magnetic field sensing units, and a switching circuit is provided. The substrate has a surface, and has a first inclined surface and a second inclined surface. The first magnetic field sensing unit includes a plurality of magnetoresistance sensors connected together to form a Wheatstone full bridge and disposed on the surface. The second magnetic field sensing unit includes a plurality of magnetoresistance sensors connected together to form a Wheatstone half bridge and disposed on the first inclined surface. The third magnetic field sensing unit includes a plurality of magnetoresistance sensors connected together to form a Wheatstone half bridge and disposed on the second inclined surface. The switching circuit electrically connects the second magnetic field sensing unit and the third magnetic field sensing unit. A magnetic field sensing module is also provided.