Heat-Resistant Current Sensor with Ceramic Substrate
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Solution Overview
Problem
Current current sensors based on printed substrates in harsh environments, such as engine rooms, face reliability issues due to thermal expansion and deformation, which affect their current-sensing capability.
Innovation Solution
A heat-resistant device with a ceramic substrate embedding power wirings and a coil structure, where conductors and connection wirings are arranged to maintain consistent spacing and prevent exposure outside the substrate, utilizing materials like alumina, silica, and copper to enhance thermal stability and electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a current sensor based on a printed substrate is placed in a harsh environment, then the device can operate in high-temperature conditions, but the printed substrate may be thermally expanded or deformed, possibly lowering the current-sensing capability
Solution Approach 1:
The patent changes the substrate material parameter from conventional printed substrate to heat-resistant ceramic substrate, which has fundamentally different thermal expansion properties and higher temperature stability, thereby resolving the contradiction between heat resistance and measurement precision
Solution Approach 2:
The patent employs a composite structure combining ceramic substrate with metal power wirings and coil structure, where each material is selected for its specific properties (ceramic for thermal stability, metal for electrical conductivity), creating a composite system that achieves both heat resistance and sensing accuracy
2Stability of the object's composition
If the coil structure is embedded in the heat-resistant substrate, then the geometric integrity is maintained under thermal stress, but the manufacturing complexity increases due to embedding requirements
Solution Approach 1:
The patent divides the device into distinct embedded components (power wirings, coil structure, terminal wirings) within the ceramic substrate, allowing each element to be positioned and fixed independently, which maintains geometric integrity while managing manufacturing complexity through modular embedding
3Measurement precision
If the first conductors are spaced by the substantially same minimum distance from the outer circumferential line, then the current detection accuracy is improved, but the device area increases
Solution Approach 1:
The patent applies uniform spacing (local quality consistency) of the first conductors from the outer circumferential line, which ensures equal magnetic field coupling and improves current detection accuracy, while the overall compact coil structure minimizes the total device area
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 solution improves the accuracy and reliability of current detection by suppressing thermal expansion and deformation, maintaining the geometric integrity of the sensor and reducing common mode noise, even under high-temperature conditions.
Implementation Method 1
a coil structure (30) including a coil wiring (31) extending between a start point (P1) and an end point (P2)... wherein coil units (40) each including or corresponding to one turn of the coil wiring (31) are arranged in a circumferential direction around a group of power wirings (20)
Implementation Method 2
If a current sensor based on a printed substrate is placed in the harsh environment, the printed substrate may be thermally expanded or deformed... a heat-resistant substrate (10) including a ceramic material... suppressing thermal expansion and deformation, maintaining the geometric integrity of the sensor
Data Source
AI summary
A heat-resistant device for current detection may include a heat-resistant substrate including a ceramic material; a group of power wirings embedded in the heat-resistant substrate; and a coil structure. The coil structure may include a coil wiring in which coil units each including or corresponding to one turn of the coil wiring are arranged in a circumferential direction around the group of power wirings. The coil unit may include: a first conductor; a second conductor; a first connection wiring; and a second connection wiring which may be embedded in the heat-resistant substrate. At least the first conductor and the second conductor may not be exposed outside of the heat-resistant substrate. The respective first conductors may be spaced by the substantially same minimum distance from an outer circumferential line surrounding the group of power wirings in a plane orthogonal to the extending direction of the group of power wirings.