Magnetic Sensor Package Homogeneous Field Detection
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Solution Overview
Problem
Existing magnetic sensor packages face challenges in accurately detecting both the angle of rotation and the number of turns of an external magnetic field due to potential discrepancies caused by stray magnetic fields and non-uniform field strengths.
Innovation Solution
A magnetic sensor package is designed with both a magnetic single turn sensor and a magnetic multi-turn sensor integrated on the same lead frame, ensuring that both sensors experience a homogeneous magnetic field, thereby minimizing the impact of stray fields and ensuring accurate measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If sensor dies are placed at different positions to detect magnetic field, then both angle and turn count can be detected, but stray magnetic fields cause discrepancies in sensor outputs
Solution Approach 1:
The patent combines multiple sensor dies (single-turn and multi-turn sensors) into a single integrated package mounted on the same lead frame, ensuring they experience identical magnetic field conditions. This merging eliminates discrepancies caused by stray fields affecting sensors at different positions, while maintaining the ability to detect both angle and turn count.
Solution Approach 2:
The patent positions sensor dies at specific locations on the lead frame where they experience uniform magnetic field strength. By controlling the local magnetic field environment through precise positioning and packaging, the system ensures accurate measurements for both angle and turn count detection without interference from stray fields.
2Measurement precision
If sensors are packaged together on the same lead frame, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The patent integrates multiple sensor dies and associated circuitry into a single packaged unit on one lead frame. This merging reduces the overall system complexity by eliminating the need for separate sensor packages and their individual mounting arrangements, while maintaining high measurement accuracy through uniform magnetic field exposure.
Solution Approach 2:
The lead frame serves multiple functions simultaneously: it provides electrical connections for both sensor types, mechanical support for the integrated package, and positioning for optimal magnetic field exposure. This multi-functionality reduces device complexity by consolidating what would otherwise require separate components.
3Measurement precision
If single turn sensor is positioned closer to magnetic field source, then angle detection sensitivity is improved, but multi-turn sensor experiences non-uniform field strength
Solution Approach 1:
The patent positions both sensor dies at locations on the lead frame where they experience uniform magnetic field strength. By controlling the local magnetic field environment through precise positioning, the system maintains field uniformity for the multi-turn sensor while preserving angle detection sensitivity for the single-turn sensor.
Solution Approach 2:
The patent utilizes the vertical dimension by stacking sensor dies at different heights on the lead frame. This dimensional arrangement allows both sensors to experience the same horizontal magnetic field uniformity while maintaining their respective detection capabilities, resolving the conflict between proximity for sensitivity and uniformity for stability.
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 integrated sensor package provides a compact and accurate solution for monitoring both the angle of rotation and the number of turns of a magnetic field, ensuring reliable data in applications such as automotive systems.
Implementation Method 1
Magnetic multi-turn sensors and single turn sensors typically use magnetoresistive elements that are sensitive to an applied external magnetic field. The resistance of the magnetoresistive elements in multi-turn sensors can be changed by rotating a magnetic field within the vicinity of the sensor.
Implementation Method 2
Variations in the resistance of the magnetoresistive elements can be tracked to determine the number of turns in the magnetic field, which can be translated to a number of turns in the device being monitored.
Implementation Method 3
the sensor package is arranged so that both sensor dies sit within a homogenous magnetic field, thereby ensuring that the output signal of each sensor is not corrupted by any stray fields
Data Source
AI summary
A magnetic sensor package comprising a magnetic multi-turn sensor die and a magnetic single turn sensor die, in which both sensor dies are packaged on the same lead frame. A method of manufacturing the magnetic sensor package is also provided. A magnetic sensor system comprising a rotating magnet and the magnetic sensor package, where the sensor package is arranged so that both sensor dies sit within a homogenous magnetic field, thereby ensuring that the output signal of each sensor is not corrupted by any stray fields.