Overmolded Electronics Enclosure with Integrated Thermal and Electrical Zones

Solution Overview

Problem

Existing electronic enclosures manufactured from metal or polymeric materials, or their combinations, face deficiencies in physical properties, cost, manufacturability, and complexity due to separate manufacturing and assembly of metal and polymer components.

Innovation Solution

A single-component electronics enclosure is created by overmolding a polymeric component onto a metal component using injection molding, which is mechanically interlocked and bonded without fasteners, providing electrical isolation and attachment features for electronic components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal and polymeric components are manufactured separately and assembled using fasteners, then structural strength is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvestructural strengthVSAvoidmanufacturing complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent combines metal and polymeric components into a single integrated enclosure structure where the polymeric material is molded directly onto the metal component, eliminating separate manufacturing and assembly steps while maintaining structural integrity through the bonded interface

Inventive Principle:

Principle #5Merging (Combining)

2Strength

If metal and polymeric components are manufactured separately and assembled using fasteners, then structural strength is improved, but manufacturing cost increases

Engineering Contradiction:

Improvestructural strengthVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent combines metal and polymeric components into a single integrated enclosure structure where the polymeric material is molded directly onto the metal component, eliminating separate manufacturing and assembly steps while maintaining structural integrity through the bonded interface

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If polymeric component is used for electrical insulation, then electrical isolation is improved, but thermal management capability deteriorates

Engineering Contradiction:

Improveelectrical isolationVSAvoidthermal management

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent applies different material properties to different regions of the enclosure: the polymeric component provides electrical insulation where needed, while the metal component provides thermal conduction pathways, and selective exposure of metal surfaces enables both electrical isolation and thermal management in different locations

Inventive Principle:

Principle #3Local quality

4Temperature

If all metal component surfaces are exposed, then thermal management is improved, but electrical isolation capability deteriorates

Engineering Contradiction:

Improvethermal managementVSAvoidelectrical isolation

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent applies different material properties to different regions of the enclosure: the polymeric component provides electrical insulation where needed, while the metal component provides thermal conduction pathways, and selective exposure of metal surfaces enables both electrical isolation and thermal management in different locations

Inventive Principle:

Principle #3Local quality

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 structural compliance, electrical insulation, and thermal management while reducing manufacturing complexity and cost by integrating metal and polymeric components into a single, cohesive unit.

Implementation Method 1

overmolding a polymeric component onto part of the metal component by an injection molding process such that the polymeric component defines a second part of the enclosure body that is mechanically interlocked with the metal component

Methodology Applied

Scientific EffectInjection molding:

Implementation Method 2

The polymeric component includes at least one electrical isolation zone that electrically insulates the metal component from the electronic component located in the recess

Methodology Applied

Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 3

The metal component defines a heat sink

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

the at least one polymeric component is bonded to and mechanically interconnected with the metal component

Methodology Applied

Scientific EffectMechanical interlocking:

Data Source

PatentUS8081466B2Overmolded electronics enclosure

Publication Date: 2011.12.20 ROCKWELL AUTOMATION TECH INC

AI summary

An enclosure for electronics includes a body with a metal component and a polymeric component overmolded onto the metal component so as to be connected to the metal component without fasteners. The body defines a recess. A heat sink is defined in the metal component. A printed circuit board is located in the recess and includes a plurality of electronic components mounted thereon. The polymeric component includes at least one attachment feature that captures the printed circuit board at a select location in the recess such that: (i) at least a first one of the electronic components is electrically connected to a contact region of the metal component that is exposed through a portion of said polymeric component; (ii) at least a second one of the electronic components is electrically isolated from the metal component by an electrical isolation zone of the polymeric component; and (ii) at least a third one of the electronic components is located adjacent a thermal transfer region of the metal component that underlies the heat sink. The thermal transfer region is uncovered by the polymeric component so as to be exposed in the recess.