AMR Sensor Linearization via Magnetization Axis Orientation
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Solution Overview
Problem
Existing magnetic field sensor apparatuses face challenges in achieving a highly sensitive linearized characteristic resistance curve without the need for external macroscopic support magnets, barber's pole structures, and flip current conductors, which increase complexity and current consumption.
Innovation Solution
The apparatus includes anisotropic magneto-resistive resistor devices on a chip substrate with each resistor element having a permanent-magnetic magnetization element, allowing the measurement current to flow at a predefined linearization angle relative to the magnetization axis, eliminating the need for barber's pole structures and flip conductors, and using a single or pair of magnetization elements to provide initial magnetization, thereby simplifying the design and reducing current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If barber's pole structures are used to achieve linearized resistance curves, then measurement precision is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts and eliminates the complex barber's pole structures from the sensor design. Instead of using these intricate conductive patterns to force current flow at 45 degrees, the invention uses the natural geometry of simple rectangular resistor elements with current entering and exiting at opposite ends, achieving the same linearization effect through a fundamentally simpler configuration.
Solution Approach 2:
Rather than forcing current to flow at 45 degrees through complex barber's pole structures, the patent inverts the approach by aligning current flow perpendicular to the magnetization direction in simple rectangular elements. This reversal achieves linearization through the perpendicular relationship between current and magnetization rather than through angular current deflection.
2Measurement precision
If external macroscopic support magnets or flip conductors are used to achieve initial magnetization, then measurement precision is improved, but use of energy and device complexity increase
Solution Approach 1:
The patent applies self-service by designing the resistor elements with built-in perpendicular magnetization that automatically provides the necessary initial magnetization without requiring external flip conductors or macroscopic support magnets. The structure itself generates and maintains the required magnetic state, eliminating the need for additional energizing components.
Solution Approach 2:
The patent incorporates preliminary action by pre-magnetizing the resistor elements perpendicularly to the current flow direction during manufacturing. This preliminary magnetization is permanently established in the material structure, so no additional energy is required during operation to maintain the initial magnetization state.
3Measurement precision
If very fine barber's pole structures are arranged on resistor strips, then measurement precision is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent removes the fine barber's pole microstructures entirely from the design. Instead of requiring precise fabrication of these intricate patterns, the invention uses simple rectangular resistor elements that can be manufactured with standard precision, eliminating the need for high-precision fine structure fabrication.
Solution Approach 2:
The patent changes the geometric parameters of the resistor elements from the complex patterns required for barber's pole structures to simple rectangular shapes. This parameter change fundamentally alters the manufacturing requirements, allowing production with conventional precision rather than requiring very fine microstructure fabrication capabilities.
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
This configuration achieves a linearized characteristic resistance curve, simplifies the manufacturing process, reduces electrical connections and control electronics complexity, and lowers current consumption, enabling precise and efficient measurement of magnetic fields.
Implementation Method 1
The AMR effect (anisotropic magneto-resistive effect) is the property of a material to change its electrical resistance depending on an angle between an electrical current flowing through the material and an external magnetic field
Implementation Method 2
A magnetic field sensor apparatus using anisotropic magneto-resistive (AMR) resistor devices on a chip substrate with integrated permanent-magnetic magnetization elements
Data Source
AI summary
A magnetic field sensor apparatus is provided for measuring one magnetic field vector component He. The apparatus includes at least one anisotropic magneto-resistive resistor device (AMR resistor device) on a chip substrate, where the resistor device includes a plurality of magneto-resistive AMR resistor elements which are connected in series by electrically conductive strips. At least one permanent-magnetic magnetization element with a magnetization axis is assigned to each resistor element in such a way that the resistor element is passed through by an initial magnetization field H0 of the magnetization element in the direction of the magnetization axis. A measurement current IS flowing through the resistor element from a contact region between a first conductive strip and the resistor element to a contact region between the resistor element and a second conductive strip has a mean current direction axis at a predefined linearization angle α>0° and α<90° relative to the magnetization axis. A highly sensitive magnetic field sensor apparatus can be manufactured economically in large numbers.