Carbon Nanotube Sheet Thermal Interface Material

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Solution Overview

Problem

Current thermal interface materials using carbon nanotubes do not adequately utilize their high thermal conductivity due to inefficient structural arrangements, leading to suboptimal heat radiation from semiconductor elements in electronic devices.

Innovation Solution

A carbon nanotube sheet structure with vertically oriented carbon nanotube bundles and a resin filling layer, where the gap between bundles is optimized for thermal conductivity, allowing direct contact with heat sources and improved electrical conductivity for interconnection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If carbon nanotubes are dispersed in resin or buried with resin, then the sheet structure can be formed, but the high thermal conductivity of carbon nanotubes cannot be sufficiently utilized

Engineering Contradiction:
Improvethermal conductivityVSAvoidstructural arrangement efficiency
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The sheet is divided into multiple regions with carbon nanotube bundles arranged in specific patterns (first region with bundles extending in first direction, second region with bundles extending in second direction). This segmentation allows optimization of thermal conductivity in different directions while maintaining structural integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The carbon nanotube bundles are arranged asymmetrically with different orientations in different regions of the sheet. The first region has bundles extending in a first direction while the second region has bundles extending in a second direction, creating an asymmetric structure that optimizes thermal management for specific heat flow patterns.

Inventive Principle:
Principle #4Asymmetry

2Temperature

If indium is used as thermal conductive sheet, then good thermal conductivity is achieved, but the price is high due to rare metal demand

Engineering Contradiction:
Improvethermal conductivityVSAvoidmaterial cost
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The patent replaces expensive indium with carbon nanotubes, which are more abundant and cost-effective. The carbon nanotube sheet provides comparable or superior thermal conductivity without the high material costs associated with rare metals like indium.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention uses composite structures combining carbon nanotubes with resin or other matrix materials. This composite approach leverages the exceptional thermal conductivity of carbon nanotubes while using cheaper, structurally supportive materials for the matrix, achieving cost-effective high-performance thermal management.

Inventive Principle:
Principle #40Composite materials

3Temperature

If carbon nanotube bundles are arranged in sheet, then thermal conductivity is improved, but the gap between bundles reduces electrical conductivity

Engineering Contradiction:
Improvethermal conductivityVSAvoidelectrical conductivity
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

Different regions of the sheet have different carbon nanotube bundle arrangements optimized for their specific functions. The first region with bundles in the first direction optimizes for thermal conductivity, while the second region with bundles in the second direction provides electrical conductivity pathways, allowing each region to have local quality optimized for its purpose.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The carbon nanotube sheet is designed to perform multiple functions simultaneously - thermal management and electrical conduction. By arranging bundles in different directions in different regions, the sheet achieves both high thermal conductivity for heat radiation and sufficient electrical conductivity for interconnection purposes.

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

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 carbon nanotube sheet achieves enhanced thermal and electrical conductivity, effectively radiating heat from semiconductor elements and serving as a high-performance interconnecting material in electronic instruments.

Implementation Method 1

a first region in which a plurality of bundles of carbon nanotubes are arranged, each bundle extending in a first direction, and a second region in which a plurality of bundles of carbon nanotubes are arranged, each bundle extending in a second direction

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

serving as a high-performance interconnecting material in electronic instruments

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP2061077B1Sheet structure and method of manufacturing the same
Publication Date: 2015.11.11 FUJITSU LTD
  • EP2061077B1 patent drawingFigure 1A~1B
  • EP2061077B1 patent drawingFigure 2
  • EP2061077B1 patent drawingFigure 3

AI summary

The sheet structure includes a plurality of linear structure bundles 12 each of which comprises a plurality of linear structures of carbon atoms arranged, spaced from each other at a first gap and which are arranged at a second gap which is larger than the first gap; and a filling layer 14 filled in the first gap and the second gap and supporting the plurality of linear structure bundles 12.