Angle Sensor Multilayer Coil Overlap Design
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Solution Overview
Problem
Conventional angle sensors face challenges in downsizing due to the need for a gap between the drive coil and detection coils to prevent short-circuiting, which limits the reduction of the overall size and increases the risk of foreign substance intrusion and wire disconnection.
Innovation Solution
The design incorporates a multilayer substrate with the drive coil and two-phase detection coils on different main surfaces, allowing them to overlap and eliminating the need for a gap, thereby reducing the size and enhancing reliability by eliminating foreign substance intrusion risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gap is maintained between the drive coil and detection coils to prevent short-circuiting, then electrical reliability is improved, but the overall size of the angle sensor increases
Solution Approach 1:
The patent transitions from a planar arrangement to a three-dimensional multilayer configuration. The drive coil is positioned on one main surface of the multilayer substrate while the detection coils are positioned on another main surface, utilizing the vertical dimension (thickness direction) to separate electrically adjacent conductors. This dimensional transition eliminates the need for lateral spacing gaps while maintaining electrical isolation, thereby reducing the overall footprint of the sensor.
Solution Approach 2:
The patent implements a nested configuration where the drive coil and detection coils are vertically stacked within the multilayer substrate structure. The coils are positioned in overlapping horizontal projections but separated in the vertical direction by the substrate thickness, creating a compact nested arrangement that maximizes space utilization and eliminates the need for lateral separation gaps.
2Volume of moving object
If the drive coil outer diameter is reduced to downsize the sensor, then the overall size is reduced, but the magnetic field strength decreases
Solution Approach 1:
By positioning the drive coil and detection coils on opposite main surfaces of the multilayer substrate, the patent enables a compact radial arrangement where the drive coil can have a smaller outer diameter while maintaining effective magnetic coupling with the detection coils through the vertical separation. The magnetic field lines pass through the substrate thickness, maintaining field strength despite reduced radial dimensions.
Solution Approach 2:
The patent changes the spatial arrangement parameter from lateral separation to vertical separation, and optimizes the coil winding density and turns to compensate for the reduced outer diameter. By adjusting these parameters, the magnetic field strength is maintained at the required level while enabling a smaller coil size that contributes to overall sensor downsizing.
3Reliability
If a gap is maintained between coils, then short-circuit prevention is improved, but foreign substance intrusion risk increases
Solution Approach 1:
The patent eliminates lateral gaps between coils by transitioning to a vertical separation arrangement where the drive coil and detection coils are positioned on opposite main surfaces of the multilayer substrate. This dimensional change closes the lateral openings that would otherwise serve as entry points for foreign substances, while maintaining electrical isolation through the substrate thickness.
Solution Approach 2:
The multilayer substrate itself acts as a protective barrier (thin film/layered structure) that physically isolates the drive coil and detection coils from each other and from the external environment. This substrate layer prevents foreign substances from intruding between the coils while maintaining the necessary electrical separation, effectively combining protection with functional isolation.
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 effectively downsizes the angle sensor while maintaining reliability and preventing wire disconnection, allowing for a stronger magnetic field without increasing the drive coil's outer diameter.
Implementation Method 1
The drive coil generates a signal at a constant frequency. The detection coils receive the signal generated from the drive coil. If a target, which is a conductor, approaches the surfaces of the detection coils, this causes eddy currents to flow through the target, thereby inducing an electric power loss.
Implementation Method 2
If a target, which is a conductor, approaches the surfaces of the detection coils, this causes eddy currents to flow through the target, thereby inducing an electric power loss. This induces changes of the detected voltages.
Data Source
AI summary
An angle sensor is provided that includes a multilayer substrate having multiple layers, a drive coil in the multilayer substrate, and first and second detection coils, which can be two-phase detection coils, that are provided in the multilayer substrate. Each of the multiple layers in the multilayer substrate has a first main surface and a second main surface facing each other. The drive coil and the first and second detection coils are provided on respective different main surfaces, among the first main surfaces and the second main surfaces of the multiple layers in the multilayer substrate.