Magnetic Sensor Soft Magnetic Body Field Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic sensors face challenges in resisting strong and disturbance magnetic fields, as they can alter the magnetization of bias layers, leading to changes in output and reduced sensitivity.
Innovation Solution
A magnetic sensor design featuring element portions with laminated magnetic and non-magnetic layers, bias layers on both sides, and soft magnetic bodies on either side to convert external magnetic fields, arranged in a meander shape with gaps to improve resistance and sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a bias layer is used to supply bias magnetic field to the element portion, then the magnetic sensor can detect geomagnetism, but when a strong magnetic field is applied, the magnetization of the bias layer is broken or changed, causing output change after the applied magnetic field is removed
Solution Approach 1:
A soft magnetic body is introduced as an intermediary between the external magnetic field and the bias layer. The soft magnetic body converts the external magnetic field applied in the sensitivity axis direction into a magnetic field in a different direction, preventing direct application of strong magnetic fields to the bias layer and maintaining its magnetization stability
Solution Approach 2:
The magnetic field direction parameter is changed by the soft magnetic body. It transforms the external magnetic field from the sensitivity axis direction to a different direction, thereby altering how the magnetic field interacts with the bias layer and element portion to prevent magnetization breakdown
2Measurement precision
If the sensitivity axis direction is set to detect magnetic field in one direction, then the sensor can measure geomagnetism accurately, but resistance to disturbance magnetic field in orthogonal direction needs improvement
Solution Approach 1:
The soft magnetic body acts as a mediator that selectively converts disturbance magnetic fields in orthogonal directions into fields that do not directly affect the bias layer magnetization, while allowing the sensitivity axis detection to function normally
Solution Approach 2:
The soft magnetic body is positioned specifically on both sides of the element portion in the direction orthogonal to the sensitivity axis, providing localized magnetic field conversion only where needed to block disturbance fields while maintaining detection accuracy in the sensitivity direction
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
Enhances resistance to strong and disturbance magnetic fields, maintaining sensor stability and accuracy by effectively managing magnetic field interactions and reducing magnetic field impact on bias layers.
Implementation Method 1
Each soft magnetic body is configured such that, when an external magnetic field is applied in the first horizontal direction, the soft magnetic bodies which are provided on both sides of each element portion in the second horizontal direction convert the external magnetic field in a horizontal direction different from the first horizontal direction and supply the external magnetic field to the element portion
Implementation Method 2
Each bias layer is configured such that a bias magnetic field is supplied in the first horizontal direction from each bias layer to each element portion
Implementation Method 3
a plurality of element portions each of which is formed by laminating a magnetic layer and a non-magnetic layer and has a magneto-resistive effect
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An embodiment provides a magnetic sensor capable of improving resistance to a strong magnetic field resistance. A magnetic sensor according to an embodiment includes a plurality of element portions 9, bias layers 10 which are provided on both sides of each element portion, and soft magnetic bodies 12 which are provided so as not to contact each element portion and each bias layer. The sensitivity axis direction P1 of the element portion 9 and the magnetization direction of the bias layer 10 are the Y1-Y2 direction. Each bias layer 10 is configured such that a bias magnetic field is supplied to the element portion 9 in the X1-X2 direction. When the external magnetic field is applied in the X1-X2 direction, each soft magnetic body is configured such that it can convert the magnetic field substantially in the Y1-Y2 direction and supply the magnetic field to the element portion 9. A gap T1 is provided between the element portion 9 and the soft magnetic body 12 in a plan view. The bias layer 10 does not overlap a virtual line E which connects edge portions 12d where the distance between the soft magnetic bodies 12 is the shortest in a straight line in a plan view. In addition, the bias layer 10 is not provided between the soft magnetic bodies 12 in an element-connected body 17.