Molded Metal-Sheet Inverter Housing for EMC Gap Shielding

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current designs for the AC retainer section of a traction inverter in electric vehicles provide insufficient electromagnetic compatibility (EMC) performance, leading to EMC/EMI test failures and requiring inefficient assembly processes to address low EMC performance.

Innovation Solution

A metal sheet is molded to the inner surface of the protruding rim of the inverter housing, circumferentially surrounding the cavity and extending past the rim to shield gaps between housings, combined with an environmental seal made of dielectric material to cover the rim surfaces and partially cover the inner surface, thereby reducing EMI leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional AC retainer design is used, then assembly process is required to address EMC issues, but EMC performance remains insufficient and assembly complexity increases

Engineering Contradiction:
ImproveEMC performanceVSAvoidassembly process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the AC retainer housing with an integrated metal shield into a single molded component. The metal sheet is directly molded to the inner surface of the protruding rim, creating a unified structure that provides both mechanical retention and electromagnetic shielding functions, eliminating the need for separate EMI seals or additional assembly steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a composite structure combining plastic housing material with a metal sheet layer. The metal sheet is molded to the inner surface of the protruding rim, creating a composite component that leverages the mechanical properties of plastic and the electromagnetic shielding properties of metal to achieve superior EMC performance.

Inventive Principle:
Principle #40Composite materials

2Reliability

If multiple separate components are used for EMI shielding, then EMC performance can be improved, but part count increases and manufacturing cost increases

Engineering Contradiction:
ImproveEMC performanceVSAvoidpart count
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent merges the AC retainer housing and the EMI shield into a single integrated component. The metal sheet is directly molded to the housing structure, eliminating the need for separate EMI seal parts and reducing the total component count while maintaining effective electromagnetic shielding.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated metal-sheet AC retainer performs multiple functions simultaneously: it provides mechanical retention for electrical connectors, creates structural support, and delivers electromagnetic shielding. This multi-functionality eliminates the need for separate dedicated EMI seal components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If traditional assembly processes are used to address EMC issues, then some EMC protection is achieved, but manufacturing efficiency decreases and cost increases

Engineering Contradiction:
ImproveEMC performanceVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent incorporates the EMI shielding function directly into the molding process of the AC retainer housing. The metal sheet is molded to the housing in the same manufacturing step, performing the shielding preparation in advance during primary manufacturing rather than requiring subsequent assembly operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent combines the housing manufacturing and EMI shielding implementation into a single integrated molding process. This eliminates separate assembly steps for installing EMI seals, thereby improving manufacturing efficiency and reducing production time while ensuring consistent EMC performance.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances EMC performance, simplifies manufacturing, reduces part count, and improves vibration reliability while eliminating the need for additional EMI seals, thus providing a cost-effective assembly.

Implementation Method 1

a metal sheet, wherein the metal sheet is molded to an inner surface of the protruding rim such that the protruding rim extends past the metal sheet, and wherein the metal sheet circumferentially surrounds the cavity

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 2

an environmental seal made of dielectric material to cover the rim surfaces and partially cover the inner surface

Methodology Applied
Scientific EffectDielectric insulation: Dielectric

Data Source

PatentEP4525573B1Systems for molding metal sheet into inverter for improving EMC performance
Publication Date: 2025.12.17 BORGWARNER US TECHNOLOGIES LLC
  • EP4525573B1 patent drawingFigure 1A
  • EP4525573B1 patent drawingFigure 1B
  • EP4525573B1 patent drawingFigure 2

AI summary

An inverter may include a housing having a body and a protruding rim extending from the body, wherein the protruding rim surrounds a cavity that extends through to the body. An inverter may include one or more electrical receptacles, wherein the one or more electrical receptacles are disposed within the cavity such that a portion of at least one of the one or more electrical receptacles extends above the protruding rim. An inverter may include a metal sheet, wherein the metal sheet is molded to an inner surface of the protruding rim such that the protruding rim extends past the metal sheet, and wherein the metal sheet circumferentially surrounds the cavity.