Amorphous Alloy Magnetic Sensor with High Permeability
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Solution Overview
Problem
Current magnetic sensors using the magnetic impedance effect struggle to enhance sensitivity due to limited changes in magnetic permeability, which affects their ability to accurately measure magnetic fields.
Innovation Solution
A magnetic sensor design featuring a soft magnetic material layer with an initial magnetic permeability of 5,000 or more, composed of amorphous alloys like Co, Fe, Si, B, and Mn, and including magnetic domain suppression and conductor layers to reduce noise and increase impedance changes, thereby improving sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional soft magnetic material films with limited initial magnetic permeability are used, then the device complexity remains simple, but the sensitivity of the magnetic sensor is insufficient
Solution Approach 1:
The patent employs composite material structures including amorphous alloy soft magnetic material layers combined with crystalline magnetic material layers, and integrates multiple functional layers (conductor layers, magnetic domain suppression layers, antiferromagnetically coupling layers) to achieve high initial magnetic permeability (5000 or more) while maintaining a manufacturable thin-film structure
Solution Approach 2:
The patent changes material parameters by selecting amorphous alloys with specific compositions (Co-Fe-Si-B-Mn system) and controlling deposition conditions to achieve initial magnetic permeability of 5000 or more, significantly higher than conventional soft magnetic films, thereby improving sensitivity without proportionally increasing complexity
2Measurement precision
If the soft magnetic material layer thickness is increased to improve sensitivity, then the magnetic permeability change increases, but the skin depth decreases leading to reduced impedance change
Solution Approach 1:
The patent optimizes the thickness parameter of the soft magnetic material layer to a specific range (100 nm to 1 μm) where the initial magnetic permeability is 5000 or more, achieving optimal balance between magnetic permeability change and skin depth effects to maximize impedance change and sensitivity
Solution Approach 2:
The patent applies local quality enhancement by concentrating the high magnetic permeability property (5000 or more) in the soft magnetic material layer while maintaining other layers with appropriate properties, creating optimal local conditions for magnetic impedance effect without requiring uniform high complexity throughout the entire structure
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 enhanced magnetic sensor achieves higher sensitivity and reduced noise by utilizing layers with high magnetic permeability and conductivity, allowing for more accurate measurement of magnetic fields.
Implementation Method 1
sensing a magnetic field by a magnetic impedance effect
Implementation Method 2
the magnetic domain suppression layer suppressing occurrence of a closure magnetic domain in the soft magnetic material layers
Implementation Method 3
the antiferromagnetically coupling layer antiferromagnetically coupling the soft magnetic material layers
Data Source
AI summary
It is aimed at improving sensitivity of a magnetic sensor using the magnetic impedance effect. A magnetic sensor includes: a non-magnetic substrate; and a sensitive element including a soft magnetic material layer composed of an amorphous alloy with an initial magnetic permeability of 5,000 or more, the soft magnetic material layer being provided on the substrate, having a longitudinal direction and a short direction, being provided with uniaxial magnetic anisotropy in a direction crossing the longitudinal direction, and sensing a magnetic field by a magnetic impedance effect.