Electronic Control Device Shielding via Electrostatic Capacitive Coupling

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Solution Overview

Problem

Electronic control devices in automobiles face challenges in reducing radiation noise and vibration-induced noise due to insufficient housing strength and machining accuracy, leading to potential collisions and increased costs or radiation leaks through gaps.

Innovation Solution

A shield structure utilizing a metal housing and an inner-layer copper foil pattern within the substrate for electrostatic capacitive coupling to shield radiation noise from electronic components, preventing electromagnetic noise leakage while maintaining structural integrity and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the housing and cover are arranged close to one another to improve shielding effectiveness, then radiation noise suppression is improved, but vibration-induced collision noise increases

Engineering Contradiction:

Improveradiation noiseVSAvoidcollision noise

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

A damping material is introduced as an intermediary layer between the housing and cover. This damping material absorbs vibration energy and prevents direct collision between metal surfaces, thereby eliminating collision noise while maintaining the close spacing needed for effective radiation noise shielding.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the direct mechanical contact between housing and cover with an electrostatic capacitive coupling system. By using the electrostatic field formed between the metal housing and substrate as the primary shielding mechanism, the need for mechanical contact is eliminated, thus preventing vibration-induced collision noise while maintaining shielding effectiveness.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Object-generated harmful factors

If the housing strength and machining accuracy are increased to prevent collision noise, then collision noise is reduced, but manufacturing cost increases

Engineering Contradiction:

Improvecollision noiseVSAvoidmanufacturing cost

Core Design Contradiction:

Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The patent uses a relatively thin and simple metal housing that does not require high strength or precision machining. By accepting that the housing may have some vibration and imperfections, and compensating for this with the damping material and electrostatic shielding mechanism, the manufacturing cost is significantly reduced while still achieving the desired noise suppression.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Object-generated harmful factors

If the housing and cover are arranged apart to prevent collision noise, then collision noise is reduced, but radiation noise leaks through gaps

Engineering Contradiction:

Improvecollision noiseVSAvoidradiation noise leakage

Core Design Contradiction:

Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The patent replaces reliance on mechanical contact for noise suppression with an electrostatic field-based shielding system. The electrostatic capacitive coupling between the metal housing and substrate creates an effective shielding barrier against radiation noise without requiring the housing and cover to be in direct contact, thus preventing both collision noise and radiation noise leakage simultaneously.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 effectively shields noise radiation from electronic components in vehicle control devices, maintaining structural integrity and reducing costs by using electrostatic capacitive coupling between the metal housing and substrate, thereby minimizing noise leakage and vibration-induced issues.

Implementation Method 1

a shield structure which shields radiation noise from the electronic component by electrostatic capacitive coupling formed between the metal portion and the metal housing

Methodology Applied

Scientific EffectElectrostatic capacitive coupling: Capacitance

Data Source

PatentUS11122717B2Electronic control device

Publication Date: 2021.09.14 ASTEMO LTD

AI summary

To obtain, in an on-board control device, a shield effect against noise radiated from an electronic component.The present invention includes: an electronic component 103; a metal housing 101 which covers at least a part of the electronic component 103; a metal portion 105 which is provided so that the electronic component 103 is disposed between the metal portion 105 and the metal housing 101; and a shield structure which shields radiation noise from the electronic component 103 by electrostatic capacitive coupling formed between the metal portion 105 and the metal housing 101.