Foam Core Dielectric Materials for RF Interconnects

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current dielectric materials used in electronic components, such as those in radar and microwave applications, face challenges including high cost, weight, and degradation under processing conditions, leading to inconsistent electrical performance and inability to withstand harsh environmental conditions.

Innovation Solution

Development of dielectric materials with low dielectric constant and low loss tangent, capable of operating across a wide temperature range (-200°C to +260°C) and atmospheric conditions, featuring low moisture absorption, stable coefficient of thermal expansion, and resistance to chemical media, allowing for use in harsh manufacturing processes and environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If glass fiber and PTFE are used as dielectric materials, then structural integrity is improved, but cost increases and weight increases

Engineering Contradiction:
Improvestructural integrityVSAvoidweight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent changes the material composition parameters by using polymer foam cores (polystyrene, polyethylene, polypropylene) instead of traditional glass fiber/PTFE composites. This substitution maintains structural integrity while significantly reducing weight and dielectric constant, directly resolving the contradiction between strength and weight.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates composite structures by bonding conductive foil to foam cores using adhesive layers. This composite approach achieves the necessary structural integrity for circuit boards while using lighter-weight foam materials instead of dense glass fiber composites, thereby reducing overall weight.

Inventive Principle:
Principle #40Composite materials

2Strength

If glass fiber and PTFE are used as dielectric materials, then structural integrity is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvestructural integrityVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent simplifies manufacturing by changing from multi-step PTFE coating processes to direct adhesive bonding of foil to foam cores. This parameter change in the manufacturing approach reduces process complexity while maintaining structural integrity through the adhesive bonding method.

Inventive Principle:
Principle #35Parameter changes

3Speed

If conventional dielectric materials are used, then signal transmission is achieved, but signal loss increases at high frequencies

Engineering Contradiction:
Improvesignal propagation speedVSAvoidsignal loss
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The patent changes the dielectric constant parameter by using foam materials with dielectric constants of 1.0-1.06 (air) or 1.4-2.3 (foam materials), compared to traditional PTFE's 2.17 or glass fiber composites' higher values. This parameter change enables faster signal propagation and reduces signal loss at high frequencies.

Inventive Principle:
Principle #35Parameter changes

4Speed

If dielectric materials with low dielectric constant are used, then signal propagation speed is improved, but material stability under processing conditions worsens

Engineering Contradiction:
Improvesignal propagation speedVSAvoidmaterial stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent uses composite structures with foam cores bonded to conductive foil layers using adhesives. This composite approach maintains material stability during processing while achieving low dielectric constants, as the foam provides structural stability and the adhesive ensures bonding integrity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies different materials to different parts of the structure: foam cores for dielectric properties, conductive foil for electrical conduction, and adhesives for bonding. This local quality assignment ensures each material performs its specific function optimally, maintaining overall stability while achieving low dielectric constant.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS7498392B2Methods and compositions for dielectric materials
Publication Date: 2009.03.03 NELSON KEVIN G

AI summary

The present invention comprises methods and compositions of dielectric materials. The dielectric materials of the present invention comprise materials having a dielectric constant of more than 1.0 and less than 1.9 and/or a dissipation factor of less than 0.0009. Other characteristics include the ability to withstand a wide range of temperatures, from both high temperatures of approximately +260° C. to low temperatures of approximately −200° C., operate in wide range of atmospheric conditions and pressures (e.g., a high atmosphere, low vacuum condition such as that found in the outer-space as well as conditions similar to those found at sea level or below sea level). The dielectric materials of the present invention may be used in the manufacture of composite structures that can be used alone or in combination with other materials, and can be used in electronic components or devices such as RF interconnects.