Highly Oriented Graphite Production via Segmented Pressure
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Solution Overview
Problem
Existing methods for producing highly oriented graphite with a thickness of not less than 20 mm are hindered by deformation and displacement due to high pressure application at high temperatures, and the material's water absorption issues lead to delamination when used in electronic devices.
Innovation Solution
A method involving the heat-treatment of laminated polymeric or carbonaceous films up to 2400°C under pressure, with a controlled pressure application to only a portion of the surface, to produce highly oriented graphite with a thickness of not less than 20 mm and reduced water absorption, ensuring minimal displacement and improved adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high pressure of 200 kg/cm2 is applied at high temperature of 2600°C to the laminated body, then the graphite layers are densified and water absorption is reduced, but the highly oriented graphite, container, and jig are significantly deformed and graphite layers are displaced
Solution Approach 1:
The patent divides the pressure application into two distinct stages: (1) preliminary pressure application at temperatures below 2000°C to establish initial contact between layers, and (2) final pressure application at temperatures of 2600°C or higher to densify the structure. This segmentation allows each pressure application to serve a specific purpose without causing deformation or displacement.
Solution Approach 2:
The patent applies preliminary pressure to the laminated body before reaching the high temperature of 2600°C, specifically at temperatures below 2000°C. This preliminary action ensures that the graphite layers are properly positioned and in contact before the high-temperature densification process, preventing displacement during the subsequent high-pressure application.
2Length of stationary object
If the thickness of graphite layers in the lamination direction is increased to not less than 20 mm, then the heat-dissipation capability is improved, but the pressure application causes displacement of graphite layers making production impossible
Solution Approach 1:
The patent segments the pressure application process into two temperature-based stages, allowing thick laminated bodies (20 mm or more) to be processed without layer displacement. The first pressure application at lower temperature prepares the structure, while the second at high temperature completes densification, making thick graphite production feasible.
Solution Approach 2:
The patent changes the temperature parameter between pressure application stages, applying pressure first at temperatures below 2000°C and then at 2600°C or higher. This parameter change enables the production of thick graphite layers by preventing displacement during the critical pressure application phases.
3Length of stationary object
If highly oriented graphite with thickness of not less than 20 mm is produced, then the thermal conductivity is enhanced, but the amount of water absorption must be严格控制 to prevent delamination during heating
Solution Approach 1:
The patent uses segmented pressure application at different temperature stages to achieve both thick layer formation and low water absorption. The two-stage process ensures proper densification throughout the 20 mm thickness, eliminating gaps where water could be absorbed while preventing delamination during subsequent heating.
Solution Approach 2:
The patent employs parameter changes in temperature and pressure application to control water absorption in thick graphite structures. By applying pressure at specific temperature ranges, the process achieves thorough densification that minimizes water absorption pathways while maintaining structural integrity for thick 20 mm layers.
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 approach enables the production of highly oriented graphite with enhanced thermal conductivity and reduced water absorption, preventing delamination and facilitating its integration into electronic devices for efficient heat transfer and dissipation.
Implementation Method 1
a graphitizing step of graphitizing the laminated body
Implementation Method 2
a pressure of not less than 20 kg/cm2 being applied to the laminated body within any temperature range that is at least not less than 2400° C.
Implementation Method 3
heat-treating the laminated body under pressure to a temperature of not lower than 3000° C.
Data Source
AI summary
Use of highly oriented graphite including graphite layers placed on top of one another and containing only a small amount of water allows for production of an electronic device that includes, as an element, highly oriented graphite in which no delamination occurs, that is highly reliable in use, and that has a good heat dissipation capability.