Magnetic Sensor Soft Magnetic Body Segmentation
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Solution Overview
Problem
Magnetic sensors face challenges in maintaining sensitivity due to residual magnetization and hysteresis issues when converting vertical magnetic fields into horizontal components, requiring precise shape accuracy and arrangement of soft magnetic bodies.
Innovation Solution
A magnetic sensor design featuring a pair of soft magnetic bodies connected to a positioning soft magnetic body, with a non-contact configuration and insulating nonmagnetic layers, allows for improved ease of fabrication and reduced sensitivity degradation by minimizing the influence of relative position changes between the soft magnetic bodies and the magneto resistive effect element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single soft magnetic body is used to convert vertical magnetic field into horizontal component, then the aspect ratio must be increased from 1.5 times to approximately 4 times, but this causes residual magnetization in the height direction and increases hysteresis
Solution Approach 1:
The soft magnetic body is divided into a pair of separate soft magnetic bodies (first and second soft magnetic bodies) that are spaced apart from each other. This segmentation prevents the formation of a continuous magnetic path in the height direction, thereby eliminating residual magnetization and hysteresis issues while maintaining the ability to convert vertical magnetic field components into horizontal components.
Solution Approach 2:
The patent transitions from a single vertical soft magnetic body to a pair of soft magnetic bodies arranged horizontally with spacing between them. This dimensional reconfiguration changes the magnetic field conversion mechanism while avoiding the harmful effects of vertical magnetization accumulation.
2Object-affected harmful factors
If a pair of soft magnetic bodies are spaced apart and connected on lower surface sides, then residual magnetization is suppressed, but the relative position between soft magnetic bodies and magneto resistive effect element must be precisely controlled
Solution Approach 1:
A positioning soft magnetic body is introduced as an intermediary component that magnetically connects the first and second soft magnetic bodies. This positioning body serves as a reference structure that defines the relative positions of the soft magnetic bodies with respect to the magneto resistive effect element, thereby reducing the impact of positional variations on sensor performance.
Solution Approach 2:
The positioning soft magnetic body is configured to preliminarily establish the correct spatial relationship between the soft magnetic bodies and the magneto resistive effect element before the actual magnetic field conversion takes place. This preliminary positioning action ensures that even with manufacturing tolerances, the sensor operates within acceptable performance parameters.
3Measurement precision
If the aspect ratio of soft magnetic body is increased to maintain sensitivity, then vertical field conversion is improved, but device height increases and offset occurs
Solution Approach 1:
By segmenting the soft magnetic body into a pair of horizontally spaced bodies, the patent eliminates the need to increase the height dimension. The magnetic field conversion function is achieved through the horizontal arrangement and magnetic interaction between the paired bodies, maintaining a compact device profile.
Solution Approach 2:
The patent shifts the design from a vertical dimension approach (increasing height) to a horizontal dimension approach (spacing apart two bodies). This dimensional transformation maintains the field conversion capability while keeping the device height low and avoiding offset issues.
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 design enhances sensor sensitivity and stability by effectively converting vertical magnetic fields into horizontal components with reduced sensitivity loss and ease of fabrication, while maintaining a low profile and high shape accuracy.
Implementation Method 1
a soft magnetic body that converts a magnetic field component in a vertical direction into a magnetic field component in a horizontal direction
Implementation Method 2
A magnetic sensor using a magneto resistive effect element can be used as a geomagnetic sensor
Data Source
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AI summary
A magnetic sensor on which structural improvement has been performed so that it is easy for a magnetic sensor with good sensor sensitivity to appropriately exhibit original functions is provided. A magnetic sensor (10) including a first magneto resistive effect element (21) located on a first surface (15A) of a substrate (15) and having a sensitivity axis in a first direction that is one of in-plane directions of the first surface (15A), a positioning soft magnetic body (40b) including a first most proximal portion (40E1) of which a relative position with respect to the magneto resistive effect element (21) is defined, and provided in a non-contact manner with respect to the first magneto resistive effect element (21), and a first soft magnetic body (35) and a second soft magnetic body (36) juxtaposed in the first direction and extending in a direction away from the first surface (15A), and each of the first soft magnetic body (35) and the second soft magnetic body (36) is magnetically connected to the positioning soft magnetic body (40b).