Magnetic Field Sensor with Flux Concentrators for Multi-Dimensional Detection
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Solution Overview
Problem
Existing 2D and 3D magnetic field sensors face challenges in manufacturing complexity, cost, and sensitivity, particularly in achieving high sensitivity across multiple dimensions and low energy consumption, while also being lightweight and easy to produce in mass quantities.
Innovation Solution
A magnetic field sensor design that includes two or three sensors with flux concentrators and magnetoresistive elements, where the reference layers have the same magnetization direction, allowing for simultaneous detection of multiple magnetic field components with simplified manufacturing and shared technological steps, and a method for writing the magnetization direction using antiferromagnetic layers with the same blocking temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple uniaxial sensors are combined to form 2D or 3D magnetic field sensors, then measurement capability in multiple dimensions is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent combines multiple uniaxial sensor functions into a single integrated structure by using one magnetoresistive element with multiple flux concentrators oriented in different directions. This merging approach achieves 2D or 3D measurement capability without requiring multiple separate sensor assemblies, thereby reducing manufacturing complexity while maintaining versatility.
Solution Approach 2:
The magnetoresistive element serves multiple functions by detecting magnetic field components in different spatial directions simultaneously. The single element is designed to respond to magnetic fields along multiple axes through the arrangement of flux concentrators, making it a multi-functional sensor that replaces what would traditionally require multiple separate sensors.
2Measurement precision
If different magnetization directions are used for reference layers in multi-dimensional sensors, then measurement sensitivity in each dimension is improved, but manufacturing precision requirements increase
Solution Approach 1:
Each flux concentrator is designed with its own specific orientation and magnetic properties tailored to detect fields in particular directions. The reference layer maintains a single magnetization direction, while the flux concentrators provide direction-specific sensitivity through their geometric and magnetic characteristics, allowing local optimization without requiring multiple reference layer orientations.
3Adaptability or versatility
If flux concentrators with different orientations are used for each sensor dimension, then measurement capability in multiple directions is improved, but device complexity increases
Solution Approach 1:
Multiple flux concentrators with different orientations are integrated around a single magnetoresistive element, merging what would be separate sensor structures into one compact device. This consolidation reduces the overall device complexity while maintaining the ability to measure magnetic field components in multiple directions simultaneously.
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 design enhances sensitivity and reduces manufacturing complexity, enabling cost-effective production of sensors with high sensitivity across multiple dimensions, while maintaining low energy consumption and lightweight characteristics.
Implementation Method 1
The flux concentrator F makes it possible to capture the magnetic flux that is created by the field B to be measured in the direction X of its large dimension L1, and to amplify this field B to be measured on a magnetoresistive element MR
Implementation Method 2
The magnetoresistive element MR is typically inserted into the air gap E of the flux concentrator F... the magnetoresistive element MR makes it possible to transform a variation in the magnetic field into a variation of electrical resistance
Implementation Method 3
The trapping of the reference layer is in general carried out by interaction with an antiferromagnetic layer adjacent to the reference layer, by an anisotropic exchange mechanism
Data Source
AI summary
A magnetic field sensor includes first and second sensors for detecting first and second magnetic components according to first and second directions. Each sensor includes a flux concentrator including first and second magnetic parts, an air gap between the parts, and a magnetoresistive element in the air gap. Each magnetoresistive element includes a reference layer having a fixed magnetization direction, the fixed magnetization direction of the first and second sensors being substantially identical, and a sensitive layer having a variable magnetization direction, the variable magnetization direction of the first sensor when the first sensor is in a state of rest being substantially identical to the variable magnetization direction of the second sensor when the second sensor is in the state of rest. The air gaps of first and second sensor are oriented parallel to a direction XY which is, at ±15°, the bisector of the first and second directions.