Current Sensor Case Shielding for dV/dt and EMC Improvement
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Solution Overview
Problem
Existing electronic component units, such as current sensing devices, face challenges in enhancing their quality, particularly in improving the dV/dt characteristic and EMC characteristics.
Innovation Solution
The integration of a shield layer with conductivity and magnetism on the inner surface of the case within the electronic component unit, which can be formed by stacking layers of conductive and magnetic materials or by mixing these materials into a single layer, effectively addresses the quality enhancement needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a shield layer with both conductivity and magnetism is introduced, then the dV/dt characteristic and EMC characteristic are improved, but the device structure becomes more complex
Solution Approach 1:
The patent combines both conductive and magnetic properties into a single shield layer that performs dual functions simultaneously. This merging of functions reduces the need for separate conductive and magnetic shielding layers, thereby improving reliability while controlling structural complexity.
Solution Approach 2:
The shield layer is constructed using composite materials that possess both conductivity and magnetism. This allows a single layer to provide both electrical shielding (improving dV/dt characteristic) and magnetic shielding (improving EMC characteristic), resolving the technical contradiction between enhanced reliability and simplified structure.
2Duration of action of stationary object
If the shield layer is placed on the inner surface of the case, then the shield layer is protected and its effect is maintained longer, but it may interfere with members on the outer side
Solution Approach 1:
The patent applies the shield layer selectively on specific inner surfaces of the case where protection is most needed, rather than uniformly across all surfaces. This localized application protects the shield layer and maintains its effectiveness while minimizing potential interference with outer components, as the shielding is concentrated where it provides maximum benefit.
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 solution enhances the dV/dt characteristic through conductivity and improves the EMC characteristic through magnetism, resulting in improved noise immunity and electromagnetic compatibility, thereby enhancing the overall quality of the electronic component unit.
Implementation Method 1
a shield layer placed on at least part of a surface on an inner side of the case and having conductivity and magnetism, wherein the conductivity contributes to an improvement in a dV/dt characteristic
Implementation Method 2
a shield layer placed on at least part of a surface on an inner side of the case and having conductivity and magnetism, wherein the magnetism contributes to an improvement in an EMC characteristic
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
To provide an art capable of enhancing the quality of an electronic component unit. A shield layer 50 is placed on a first surface 11a, a second surface 12a, or a third surface 13a of a case 10 of an electronic component unit (current sensor). For the shield layer 50, various pastes (a carbon paste and a magnetic paste) are adopted. Capable of freely coating a desired place, the pastes can form an appropriate shielding structure, making it possible to easily improve both a dV/dt characteristic and an EMC characteristic. Further, adding the magnetic paste enables the shielding of a radio noise band (a frequency band of around 0.1 to 5.0 MHz). Further, being formed of the pastes, the shield layer 50 can be formed at a lower cost than a metal shield (film formed by vacuum deposition such as vapor deposition or sputtering).