A flexible phase change material for thermal control of electronic devices

A technology of phase change materials and electronic equipment, applied in heat exchange materials, modification through conduction heat transfer, cooling/ventilation/heating modification, etc., can solve problems such as inability to separate crystal phases, fracture damage, and high surface contact thermal resistance , to achieve the effect of improving thermal control performance, increasing the use of space and cost, and good coordination

Active Publication Date: 2020-06-26
UNIV OF SCI & TECH OF CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the existing preparation technology, the polyolefins used are mostly conventional polymers, such as high-density polyethylene, low-density polyethylene, polypropylene, etc., and the fiber orientation degree of such polymers is low (< 95%), and the molecular chain The arrangement is mostly linear, there is no physical cross-linking form, and the crystal phase cannot be separated, so it has no elasticity and high mechanical strength. The composite phase change material prepared by melting and mixing with the phase change material has a large macroscopic hardness. The tensile mechanical properties are poor, and the tensile failure is directly broken without passing through the yield stage.
[0006] It can be seen from the above that for the existing composite PCM, the greater strength and hardness lead to poor ductility and deformation resistance of PCM, and poor processability
It is prone to damage when it is installed with special structural devices, and it is prone to brittle fracture when it is cut, stretched and compressed. It cannot be processed into a film, and it is often processed into a block or strip.
Therefore, the contact with the controlled component is a solid-solid contact, and there is a problem of high surface contact thermal resistance, especially for devices with irregular structures, the contact thermal resistance is a problem that seriously affects the heat dissipation of the device

Method used

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  • A flexible phase change material for thermal control of electronic devices
  • A flexible phase change material for thermal control of electronic devices
  • A flexible phase change material for thermal control of electronic devices

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] Preparation of octadecyl flexible phase change material, the specific operation steps are as follows:

[0037] In step (1), 150 g of octadecane and 50 g of olefin block copolymer (OBC) are taken; octadecane is the phase change matrix, the phase change temperature is 26.2°C, and the phase change latent heat is 201.6 J / g; OBC is the support carrier.

[0038] Step (2), place 150g of octadecane in an oil bath kettle body and heat it at a constant temperature at 40°C for about 30 minutes until it is completely melted;

[0039] Step (3), add 50g OBC, the temperature is 170℃, and the speed of the stirrer is set to 30r / min. Heat for 30min while stirring, and stir the two substances evenly until the OBC is completely melted, and a uniformly mixed molten composite is obtained. Things. At the same time, the cutter for surface treatment of the phase change material and the mold for holding the molten composite are respectively placed on a copper plate at 50°C for preheating.

[0040] Step...

Embodiment 2

[0047] The operation steps for preparing paraffin-based flexible phase change materials are as follows:

[0048] Step (1): Take 160 g of paraffin wax, 40 g of olefin block copolymer (OBC) and 6 g of expanded graphite (EG01). Paraffin wax is the phase change matrix, the phase change temperature is 52.6℃, the latent heat of phase change is 210J / g; OBC is the support carrier; EG01 is the thermal conductivity enhancer, the particle size is 282um, and the expansion is 550 times. The dosage of EG01 is 3% of the total mass of paraffin wax and OBC.

[0049] Step (2), place 160g of paraffin wax in an oil bath kettle body at a constant temperature of 60°C for about 30 minutes, until it melts completely;

[0050] Step (3), add 40 g of olefin block copolymer (OBC), set the temperature to 170°C, set the speed of the stirrer to 30r / min, heat for 30 minutes while stirring, and stir the two substances evenly until the OBC is completely melted. A molten composite of evenly mixed paraffin and OBC is...

Embodiment 3

[0056] The operation steps for preparing polyethylene glycol-based flexible phase change materials are as follows:

[0057] Step (1), take 140g polyethylene glycol, 60g polyurethane and 10g carbon nanotubes.

[0058] Polyethylene glycol is the phase change matrix, the relative molecular mass is 10000, the phase transition temperature is 67.18℃, the phase change latent heat is 187.3J / g; the polyurethane is the support carrier; the mass ratio of polyethylene glycol to polyurethane is 70:30. Carbon nanotubes are heat conduction enhancers. The model of carbon nanotubes is CNTS107, with a diameter of more than 50nm and a length of 10-20μm.

[0059] Step (2): Put 140g polyethylene glycol in the kettle body and heat it at 70°C for 30 minutes until the polyethylene glycol is completely melted;

[0060] Step (3), add 60g of polyurethane, set the temperature to 190°C, set the speed of the stirrer to 35r / min, turn on the vacuum pump to ensure that the kettle body maintains a vacuum degree of 0.0...

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Abstract

The invention relates to a flexible phase-change material for electronic device thermal control. The flexible phase-change material comprises a phase-change substrate and a support carrier. The support carrier is an elastic polymer. The flexible phase-change material is prepared by the following steps: heating the phase-change substrate and the support carrier in the certain temperature, and placing in the environment of which the temperature is higher than the phase-change temperature after completely fusing and mixing, cooling and rolling. The flexible phase-change material can produce the deformation, such as elastic stretching, bending and torsion, while the temperature is higher than the phase transformation point. The flexible phase-change material is adhered to the surface of the heat production part or filled in clearances between a hot plate and a packaging component while used for the electronic device thermal control. The phase-change material has the good flexibility, so the phase-change material has the performance of a thermal interface material, and is capable of reducing the contract thermal resistance. The flexible phase-change material is capable of solving the problems that the installation is difficult and the contract thermal resistance is larger because the common phase-change material is excessive hard in the thermal control process of the electronic device, and greatly improving the thermal control performance.

Description

Technical field [0001] The invention relates to the technical field of phase change materials, in particular to a preparation technology and phase change thermal control technology of a composite phase change material. Background technique [0002] With the development of aerospace and electronic technology, electronic equipment tends to be highly integrated and high-power, and the heat generated by the device has increased sharply, which has brought great challenges to the heat dissipation of electronic equipment, especially the increasingly compact structure of electronic equipment The conventional cooling method puts forward space restrictions, making the cooling of electronic equipment more difficult. One way to solve this problem currently is to use high thermal conductivity interface materials, such as thermally conductive adhesives, thermally conductive pastes, and phase change thermally conductive adhesives. Most of the chip heat dissipation is mainly transmitted through...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K5/06C08L53/00C08K5/01C08L91/06C08K7/24H05K7/20
CPCC08K5/01C08K2201/011C08L71/02C08L91/06C08L2205/03C09K5/06H05K7/20H05K7/2039C08L53/00C08K7/24C08L75/04
Inventor 程文龙李皖皖年永乐
Owner UNIV OF SCI & TECH OF CHINA
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