Magnetoresistive Sensor With Adjacent Vortex Layers

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Solution Overview

Problem

Magnetoresistive vortex- or eddy-based sensors with incorrectly aligned reference systems react to external magnetic fields in unintended directions due to the influence of both x and y fields on the vortex magnetization, and stabilization of the reference layer orientation is challenging due to mechanical stresses.

Innovation Solution

Incorporating adjacent magnetically free layers with vortex magnetization next to the magnetoresistive sensor element, aligned along the predetermined direction, to increase sensitivity in that direction and reduce sensitivity in perpendicular directions, while stabilizing the reference layer orientation with a stray field generated by these adjacent layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If vortex magnetization is used in the magnetically free layer, then the sensor can detect external magnetic fields, but the sensor reacts to magnetic fields in unintended directions due to influence on vortex magnetization

Engineering Contradiction:

Improvesensitivity in predetermined directionVSAvoidresponse to magnetic fields in unintended directions

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

Adjacent magnetically free layers with vortex magnetization are introduced as intermediary elements between the external magnetic field and the sensor element. These adjacent layers generate stray fields that mediate the interaction, enhancing sensitivity in the predetermined direction while suppressing responses to magnetic fields in perpendicular directions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies different magnetic properties to different parts of the sensor structure. The adjacent magnetically free layers have vortex magnetization configured to generate specific stray field patterns that are localized to enhance sensitivity in the predetermined direction while having minimal effect on perpendicular directions, creating directionally selective magnetic properties.

Inventive Principle:

Principle #3Local quality

2Reliability

If the reference layer orientation is stabilized, then the sensor accuracy improves, but mechanical stresses make stabilization challenging

Engineering Contradiction:

Improvereference layer orientation stabilityVSAvoidmechanical stresses on reference layer

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The patent replaces mechanical stabilization methods with a magnetic field-based approach. Instead of using mechanical structures to constrain the reference layer orientation, adjacent magnetically free layers generate stray fields that magnetically stabilize the reference layer orientation, eliminating the need for mechanical constraint systems and their associated stresses.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The stray fields from adjacent magnetically free layers serve as an intermediary stabilization mechanism. These magnetic fields mediate the interaction between external magnetic fields and the reference layer, providing orientation stability without direct mechanical contact or constraint, thereby avoiding mechanical stress-induced misalignment.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 proposed solution enhances the sensitivity of the magnetoresistive sensor in the predetermined direction and reduces its sensitivity in perpendicular directions, effectively stabilizing the reference layer orientation and improving the sensor's accuracy and reliability.

Implementation Method 1

the reference layer or the reference system of the magnetoresistive sensor element can be stabilized by a stray field generated by the adjacent magnetically free layers

Methodology Applied

Scientific EffectStray field: Magnetic Field

Implementation Method 2

Magnetoresistive effects comprise a number of different physical phenomena, wherein it is common to all of them that an electrical resistance value of a magnetoresistive element can be changed by the behavior of an external magnetic field which acts on the magnetoresistive element

Methodology Applied

Scientific EffectMagnetoresistive effect: Magnetoresistance

Implementation Method 3

a magnetically free layer having a magnetically free vortex magnetization

Methodology Applied

Scientific EffectVortex magnetization: Magnetic Field

Data Source

PatentUS20250199095A1Magnetoresistive sensor

Publication Date: 2025.06.19 INFINEON TECHNOLOGIES AG

AI summary

The implementation proposes a magnetoresistive sensor, including at least one xMR sensor element formed from a layer stack, having a magnetically free layer having a magnetically free vortex magnetization, and having at least one reference layer having a reference magnetization in a predetermined direction. Magnetically free layers having a magnetically free vortex magnetization that are arranged along the predetermined direction on opposite sides of the xMR sensor element and laterally adjacent to the xMR sensor element. The adjacent magnetically free layers can act as magnetic flux concentrators for the magnetoresistive sensor element arranged therebetween.