Stacked Magnetic Sensor Structure for Perpendicular Field Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing magnetic field detection units face challenges in achieving miniaturization and improving detection accuracy, particularly in detecting magnetic fields perpendicular to the substrate plane using magnetoresistive effect elements.
Innovation Solution
A magnetic sensor design featuring a stacked structure with a magnetic yoke and discrete magnetic field generators, including an exchange-coupled bias structure with ferromagnetic and antiferromagnetic bodies, allows for precise magnetic field detection while minimizing size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic sensor uses a stacked structure with discrete magnetic field generators and a magnetic yoke, then detection accuracy for magnetic fields perpendicular to the substrate is improved, but the device size increases
Solution Approach 1:
The patent transitions from planar magnetic field generation to three-dimensional stacked structure. Magnetic field generators are arranged in multiple tiers (first tier with first magnetic field generators, second tier with second magnetic field generators) perpendicular to the substrate plane, enabling magnetic field application in the vertical direction to improve detection accuracy while maintaining a compact footprint.
Solution Approach 2:
The magnetic yoke is positioned between the first and second magnetic field generators in the vertical stacking direction, creating a nested arrangement where the yoke is surrounded by magnetic field generators on multiple sides. This nested structure allows efficient magnetic field distribution to the detection element while minimizing the overall device volume.
2Stability of the object's composition
If multiple magnetic field generators are disposed discretely along the first-axis direction, then magnetic field distribution uniformity is improved, but the device complexity increases
Solution Approach 1:
The magnetic field generation function is segmented into multiple discrete magnetic field generators positioned at different locations (first magnetic field generator at first end, second magnetic field generator at second end) along the first-axis direction. Each generator independently contributes to the magnetic field distribution, achieving uniform field distribution across the detection element while allowing modular design and simplified manufacturing.
3Volume of moving object
If the distance between magnetic field generators is reduced to achieve miniaturization, then detection accuracy may deteriorate, but device size decreases
Solution Approach 1:
The patent resolves the size-accuracy tradeoff by utilizing the vertical dimension for magnetic field generation. Instead of increasing horizontal separation distance between magnetic field generators, the design stacks generators in the vertical direction (first tier and second tier in second-axis direction), maintaining small planar footprint while ensuring sufficient magnetic field strength and uniformity for accurate detection.
Solution Approach 2:
The magnetic yoke material is specifically selected to have high magnetic permeability, enabling it to efficiently conduct and distribute magnetic flux from the discrete magnetic field generators to the detection element. This composite approach (high-permeability yoke material + discrete generators) maintains detection accuracy even with reduced generator spacing by optimizing the magnetic circuit efficiency.
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 enables accurate magnetic field detection in a predetermined direction while achieving miniaturization, enhancing the performance of magnetic field detection units, position detection units, lens modules, and imaging apparatuses.
Implementation Method 1
The magnetic field generators are disposed discretely along a first-axis direction and each apply a magnetic field to the magnetic field detection element
Implementation Method 2
A magnetic sensor including a magnetoresistive effect element has been used in various applications
Implementation Method 3
The magnetic field generators each include an exchange-coupled bias structure including a ferromagnetic body and an antiferromagnetic body, the antiferromagnetic body being in contact with and exchange-coupled to the ferromagnetic body
Implementation Method 4
The magnetic field generators each include an exchange-coupled bias structure including a ferromagnetic body and an antiferromagnetic body
Data Source
AI summary
A magnetic sensor includes first and second tiers stacked in a second-axis direction. The first tier includes a magnetic yoke. The second tier includes: a magnetic field detection element; and magnetic field generators disposed along a first-axis direction and applying a magnetic field to the magnetic field detection element. The magnetic field detection element is interposed between two magnetic field generators in the first-axis direction. The magnetic yoke extends in the first-axis direction, and is adjacent to the magnetic field detection element in a third-axis direction in a plan view as viewed in the second-axis direction. The magnetic field generators include first and second magnetic field generators disposed at opposite ends in the first-axis direction. A distance between a first edge of the first magnetic field generator and a second edge of the second magnetic field generator is smaller than a length of the magnetic yoke in the first-axis direction.