Conductive Porous Material Assemblies for EMI Shielding and Flame Retardancy

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Solution Overview

Problem

Existing EMI shielding materials face challenges in achieving flame retardancy without compromising their shielding properties, and some regions restrict the use of silver plating, necessitating the development of alternative methods for creating electrically conductive porous material assemblies that are both effective and compliant.

Innovation Solution

The method involves creating electrically conductive porous material assemblies by applying plated mesh to plated foam using an adhesive, followed by a halogen-free flame retardant coating, which maintains Z-axis conductivity and achieves desired flame ratings without silver plating, allowing for production in regions where silver plating is restricted.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silver plating is applied to porous substrate to achieve electrical conductivity, then shielding effectiveness is improved, but manufacturing compliance deteriorates due to regional restrictions on silver plating

Engineering Contradiction:

Improveshielding effectivenessVSAvoidmanufacturing compliance

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts the essential function of silver plating (providing electrical conductivity for EMI shielding) and replaces it with an alternative material system. Specifically, copper or nickel plating is applied to the porous substrate instead of silver, achieving the same shielding effectiveness while complying with regional manufacturing restrictions that prohibit silver plating.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the material parameter of the conductive coating from silver to copper or nickel. This substitution maintains the electrical conductivity required for EMI shielding while eliminating the manufacturing compliance issues associated with silver plating restrictions in certain regions.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If flame retardant is impregnated into porous substrate to achieve flame retardancy, then flame rating is improved, but shielding properties deteriorate

Engineering Contradiction:

Improveflame ratingVSAvoidshielding properties

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention applies different treatments to different components of the shielding assembly to preserve their respective functions. The porous substrate is impregnated with flame retardant to achieve UL-94 V-0 flame rating, while the copper or nickel plating layers maintain electrical conductivity for EMI shielding. This localized functional differentiation resolves the contradiction between flame retardancy and shielding properties.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention creates a composite structure combining flame-retardant-treated porous substrate with metal plating layers. The composite material system allows the substrate to provide flame retardancy while the metal layers provide electrical conductivity, thereby achieving both flame rating improvement and shielding property preservation simultaneously.

Inventive Principle:

Principle #40Composite materials

3Reliability

If porous substrate is made electrically conductive through plating to achieve shielding effectiveness, then EMI shielding is improved, but flame retardancy deteriorates

Engineering Contradiction:

Improveshielding effectivenessVSAvoidflame retardancy

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention merges multiple functional treatments into a single integrated assembly: copper or nickel plating for electrical conductivity, flame retardant impregnation for flame suppression, and adhesive bonding for structural integrity. This combination allows the porous substrate assembly to simultaneously achieve EMI shielding effectiveness and flame retardancy, resolving the contradiction between these two properties.

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 resulting assemblies exhibit excellent shielding effectiveness and flame retardancy, meeting UL-94 V-0 standards while maintaining electrical conductivity, making them suitable for electromagnetic interference shielding applications.

Implementation Method 1

applying plated mesh to plated foam using an adhesive

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

followed by a halogen-free flame retardant coating, which maintains Z-axis conductivity and achieves desired flame ratings

Methodology Applied

Scientific EffectFlame retardancy:

Implementation Method 3

maintaining electrical conductivity

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP2763520B1Electrically conductive porous material assemblies and methods of making the same

Publication Date: 2017.12.20 LAIRD TECHNOLOGIES INC

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AI summary

Disclosed are exemplary embodiments of electrically conductive porous material assemblies. Also disclosed are exemplary methods of making or producing electrically conductive porous material assemblies. In an exemplary embodiment, an electrically conductive porous material assembly generally includes an electrically conductive porous material and a first layer of electrically conductive porous fabric. A first layer of adhesive is between the first layer of electrically conductive porous fabric and the electrically conductive porous material.