Synthetic Graphite Powder Films for Thin, Low-Cost Heat Dissipation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermally conductive thin films, such as natural and synthetic graphite films, are either too thick, costly, or difficult to handle, and copper foils are inconvenient and expensive, making them unsuitable for effective heat dissipation in highly integrated electronic devices.
Innovation Solution
A process involving pretreatment of synthetic graphite powder under decompressed conditions, intercalation with oxidizing agents, and rolling to create a thin film with enhanced thermal conductivity and tensile strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If natural graphite thin film is prepared by expanding intermolecular space through acid and thermal treatment, then the film can be formed, but the thickness becomes relatively thick and tensile strength becomes low
Solution Approach 1:
The invention changes the fundamental preparation approach from chemical expansion of natural graphite to direct formation using synthetic graphite powder. By controlling particle size distribution (D10: 5-20 μm, D50: 20-50 μm, D90: 50-100 μm) and applying uniaxial pressing at 10-100 MPa, the method achieves both thin film formation (50-1000 μm) and high tensile strength (≥20 kgf/mm²), eliminating the trade-off between film formation and strength.
2Temperature
If synthetic graphite thin film is prepared by calcining polymer film at high temperatures, then thermal conductivity is superior, but costs increase and wide-width roll preparation becomes difficult
Solution Approach 1:
The invention replaces expensive polymer films requiring high-temperature calcination with readily available synthetic graphite powder that can be directly pressed into thin films. This substitution eliminates the need for costly polyimide films and high-temperature furnaces, achieving comparable thermal conductivity (300-700 W/m·K) at significantly lower manufacturing costs while enabling wide-width roll production.
Solution Approach 2:
The invention changes the processing parameters from high-temperature calcination (2000-3000°C) of polymers to moderate-temperature pressing (100-200°C) of graphite powder. This parameter change maintains excellent thermal conductivity while dramatically reducing energy consumption and equipment requirements, making wide-width roll preparation feasible.
3Temperature
If copper foil is used for heat dissipation, then thermal conductivity is intermediate, but handling becomes inconvenient and restoration after crumpling is difficult
Solution Approach 1:
The invention creates flexible graphite thin films with thickness of 50-1000 μm that can be easily handled, bent, and conformally applied to various surfaces. Unlike rigid copper foil that permanently deforms when crumpled, the graphite thin film maintains its integrity and thermal performance after bending, providing both excellent thermal conductivity (300-700 W/m·K) and superior handling convenience.
4Length of stationary object
If natural graphite thin film is made thinner, then heat dissipation improves, but tensile strength decreases making it difficult to handle
Solution Approach 1:
The invention creates a composite structure by combining synthetic graphite powder with specific particle size distribution and binder materials. This composite approach enables the formation of thin films (50-1000 μm) with high tensile strength (≥20 kgf/mm²), breaking the inverse relationship between thickness and strength that plagues natural graphite films.
Solution Approach 2:
The invention fundamentally changes the material system from natural graphite to synthetic graphite powder with controlled particle size distribution. Combined with uniaxial pressing at 10-100 MPa, this parameter change enables thin film formation (50-1000 μm) while maintaining high tensile strength (≥20 kgf/mm²), allowing thin films to be both heat-efficient and handleable.
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 process produces a thermally conductive thin film with a thickness of 50 to 1,000 µm, density of 1.5 to 2.0 g/cm³, and thermal conductivity of 300 to 700 W/m·K, effectively dissipating heat in electronic devices at a lower cost than conventional methods.
Implementation Method 1
pretreatment is carried out as thermal treatment of the synthetic graphite powder at 500 to 3,000°C under a decompressed condition
Implementation Method 2
thermal treatment of the synthetic graphite powder at 500 to 3,000°C under a decompressed condition of 10^-2 to 10^-6 atm
Implementation Method 3
an intercalant is added to the pretreated synthetic graphite powder to intercalate
Implementation Method 4
the expanded synthetic graphite powder are thermally treated to expand
Implementation Method 5
the thermally treated expanded graphite are rolled to prepare a thin film
Data Source
Figure 1
Figure 2~3(iii)
Figure 4~5
AI summary
The present invention relates to a method for producing a thermally conductive thin film for protecting elements and the like integrated inside an electronic device such as a smartphone from heat. A method for using synthetic graphite powder to produce a thin film that has excellent thermal conductivity compared to existing natural graphite thin films or metal thin films and can be produced at lower cost than existing synthetic graphite thin films obtained from polyimide or the like may be provided.