Magnetic Sensor Manufacturing for Variable Free-Layer Magnetization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing magnetic sensors do not effectively enable the magnetization direction of the free layer of magnetoresistive elements to be different from each other, limiting their functionality and application in various magnetic field detection scenarios.
Innovation Solution
A manufacturing method for a magnetic sensor that includes forming a magnetoresistive element with a magnetization pinned layer and a free layer, and a magnetic field generator with a ferromagnetic and antiferromagnetic portion, where the magnetization direction of the ferromagnetic portion is fixed using laser light and an external magnetic field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional magnetic sensor structure is used, then the manufacturing process is simple, but the magnetization direction of the free layer cannot be varied to enable different detection scenarios
Solution Approach 1:
The magnetic field generator is segmented into distinct functional portions: a ferromagnetic portion for generating the magnetic field and an antiferromagnetic portion for fixing the magnetization direction. This segmentation allows independent optimization of each portion's properties, enabling varied magnetization directions in different sensors while maintaining a modular manufacturing approach.
Solution Approach 2:
The antiferromagnetic portion is selectively formed in specific regions to fix the magnetization direction of the ferromagnetic portion in predetermined directions. By controlling the location and orientation of the antiferromagnetic portion, the invention achieves local control over magnetization direction, enabling different detection scenarios without requiring complete redesign of the entire sensor structure.
2Adaptability or versatility
If the magnetization direction is fixed during manufacturing, then the manufacturing process is simple, but the sensor cannot adapt to different magnetic field detection scenarios
Solution Approach 1:
The antiferromagnetic portion is formed in advance during the manufacturing process to pre-fix the magnetization direction of the ferromagnetic portion. This preliminary action of setting the magnetization direction through selective formation of the antiferromagnetic layer allows the sensor to be manufactured with predetermined detection capabilities, while still enabling different detection scenarios by adjusting the formation conditions of the antiferromagnetic portion.
Solution Approach 2:
The invention controls the magnetization direction by changing the formation parameters of the antiferromagnetic portion, such as its location, thickness, and orientation. By adjusting these parameters during manufacturing, different magnetization directions can be achieved, enabling the sensor to adapt to various detection scenarios without fundamentally changing the manufacturing process flow.
3Adaptability or versatility
If adjacent magnetoresistive elements have the same magnetization direction, then the manufacturing process is consistent, but the sensor cannot detect magnetic fields in multiple directions simultaneously
Solution Approach 1:
The antiferromagnetic portion is selectively formed with different orientations and locations for different magnetoresistive elements, creating local variations in magnetization direction. This allows adjacent elements to have different magnetization directions (e.g., parallel or perpendicular) while maintaining a consistent manufacturing process, thereby enabling multi-directional detection capability.
Solution Approach 2:
The magnetic field generator is segmented into multiple regions, each with its own antiferromagnetic portion oriented to fix the magnetization direction in a specific orientation. This segmentation enables different regions to contribute to detecting magnetic fields in different directions, achieving multi-directional detection while maintaining manufacturing consistency through a systematic approach.
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
Enables the magnetization direction of the free layer to be varied, enhancing the sensor's ability to detect and respond to different magnetic fields, improving its performance and versatility in applications such as geomagnetic sensing and current sensing.
Implementation Method 1
a process of fixing a magnetization direction of the initial ferromagnetic portion so that the initial ferromagnetic portion becomes the ferromagnetic portion by using laser light and a first external magnetic field
Implementation Method 2
an antiferromagnetic portion including an antiferromagnetic material and exchange-coupled with the ferromagnetic portion
Data Source
AI summary
A magnetic sensor includes at least one MR element and at least one magnetic field generator. The MR element includes a magnetization pinned layer and a free layer. The magnetic field generator includes a ferromagnetic portion and an antiferromagnetic portion to be exchange-coupled with the ferromagnetic portion. A manufacturing method of the magnetic sensor includes a process of forming the at least one magnetoresistive element and a process of forming the at least one magnetic field generator. The process of forming the magnetic field generator includes a process of forming at least one initial magnetic field generator including an initial ferromagnetic portion that later becomes the ferromagnetic portion and the antiferromagnetic portion, and a process of fixing a magnetization direction of the initial ferromagnetic portion so that the initial ferromagnetic portion becomes the ferromagnetic portion by using laser light and an external magnetic field.