Composite VC heat sink containing copper/diamond composite wick structure and method for preparing same

Patent metadata

Field	Value
Publication number	US-12305928-B2
Application number	US-202217887412-A
Country	US
Kind code	B2
Filing date	Aug 12, 2022
Priority date	Aug 13, 2021
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

A composite VC heat sink containing a copper/diamond composite wick structure and a method for preparing the same are provided. The VC heat sink includes a lower shell plate. The lower shell plate is provided with a recess at a center position of an inner surface and provided with a boss with a same plane size as the recess at a center position of an outer surface, and a surface of the boss or a surface of the recess is provided with a copper/diamond composite plate. The copper/diamond composite wick structure has a three-dimensional porous structure and uses a copper/diamond sintered body as a matrix, a surface of the matrix is provided with a diamond layer, and a surface of the diamond layer is provided with a metal hydrophilic layer. The heat dissipation performance of the composite VC heat sink is maximized under the cooperation of structure and materials.

First claim

What is claimed is:

1. A composite VC heat sink containing a copper/diamond composite wick structure, comprising a lower shell plate, wherein
the lower shell plate is provided with a recess at a center position of an inner surface and provided with a boss with a same plane size as the recess at a center position of an outer surface,
a surface of the boss or a surface of the recess is provided with a copper/diamond composite plate; when the surface of the boss is provided with the copper/diamond composite plate, the surface of the recess is directly provided with the copper/diamond composite wick structure; and when the surface of the recess is provided with the copper/diamond composite plate, the copper/diamond composite wick structure is disposed on a surface of the copper/diamond composite plate,
the copper/diamond composite wick structure comprises a three-dimensional porous structure and uses a first copper/diamond sintered body as a matrix, and
a surface of the matrix is provided with a diamond layer, and a surface of the diamond layer is provided with a metal hydrophilic layer.

2. The composite VC heat sink containing the copper/diamond composite wick structure according to claim 1 , wherein
the copper/diamond composite plate has the same plane size as the boss and the recess, a thickness of the copper/diamond composite plate is 0.5 mm-3 mm, a mass fraction of a diamond in the copper/diamond composite plate is 10%-70%,
the copper/diamond composite wick structure has a porosity of 40%-80%,
a volume fraction of the first copper/diamond sintered body in the copper/diamond composite wick structure is 70 vol-90 vol %;
a thickness of the diamond layer is 10 μm-100 μm;
a thickness of the metal hydrophilic layer is 0.5 μm-5 μm;
a metal of the metal hydrophilic layer is selected from at least one of chromium, titanium, molybdenum, copper, tungsten, nickel, and cobalt; and
a mass fraction of the diamond in the first copper/diamond sintered body is 10%-90%.

3. The composite VC heat sink containing the copper/diamond composite wick structure according to claim 1 , wherein
the inner surface of the lower shell plate is provided with a plurality of support columns at uniform intervals along a width direction,
the center position of the inner surface of the lower shell plate is provided with the recess,
a first capillary wick is uniformly distributed in a channel formed between two of the plurality of support columns, and the first capillary wick is selected from at least one of a wire mesh metal, a metal powder sintered body, a metal fiber sintered body, a foamed metal, and the first copper/diamond sintered body;
the composite VC heat sink further comprises an upper shell plate, wherein
the upper shell plate and the lower shell plate are welded to form a cavity inside, a second capillary wick is uniformly distributed in the upper shell plate, and the second capillary wick is selected from at least one of the wire mesh metal, the metal powder sintered body, the metal fiber sintered body, and the foamed metal, and
the cavity comprises a working fluid.

4. The composite VC heat sink containing the copper/diamond composite wick structure according to claim 1 , wherein a preparation process of the first copper/diamond sintered body comprises:
depositing a first transition layer on first diamond particles,
plating copper on surfaces of the first diamond particles containing the first transition layer to obtain second diamond particles containing a copper coating,
mixing the second diamond particles containing the copper coating with a copper powder to obtain a mixed powder,
loosely packing the mixed powder into a graphite mold, and
carrying out a sintering to obtain the first copper/diamond sintered body.

5. The composite VC heat sink containing the copper/diamond composite wick structure according to claim 4 , wherein
a material of the first transition layer is selected from at least one of nickel, niobium, tantalum, titanium, cobalt, tungsten, molybdenum, and chromium,
a thickness of the first transition layer is 0.5 μm-30 μm,
a thickness of the copper coating is 2 μm-30 μm,
a particle size of the copper powder is 40 μm-150 μm, and
a particle size of the first diamond particles is 75 μm-500 μm.

6. The composite VC heat sink containing the copper/diamond composite wick structure according to claim 4 , wherein the sintering is carried out in a vacuum atmosphere or a reducing atmosphere at a temperature of 700° C.-1000° C. for 30 min-90 min.

7. The composite VC heat sink containing the copper/diamond composite wick structure according to claim 1 , wherein a preparation process of the copper/diamond composite wick structure comprises:
disposing a second transition layer on a surface of the first copper/diamond sintered body,
growing nano-diamond seed crystals on the first copper/diamond sintered body containing the second transition layer to obtain a second copper/diamond sintered body with nanocrystalline diamond particles adsorbed on a surface of the second copper/diamond sintered body, and
sequentially depositing the diamond layer and the metal hydrophilic layer to obtain the copper/diamond composite wick structure.

8. The composite VC heat sink containing the copper/diamond composite wick structure according to claim 7 ,
wherein a material of the second transition layer is selected from at least one of nickel, niobium, tantalum, titanium, cobalt, tungsten, molybdenum, and chromium, and a thickness of the second transition layer is 0.1 urn-10 urn;
a process of growing the nano-diamond seed crystals on the first copper/diamond sintered body containing the second transition layer comprises:
placing the first copper/diamond sintered body containing the second transition layer in a suspension containing the nanocrystalline diamond particles,
heating the suspension to boiling, and
carrying out an ultrasonic treatment and a drying to obtain the second copper/diamond sintered body with the nanocrystalline diamond particles adsorbed on the surface of the second copper/diamond sintered body;
wherein in the suspension containing the nanocrystalline diamond particles, a mass fraction of diamond mixed particles is 0.01%-0.05%, and a particle size of the nanocrystalline diamond particles in the suspension is 5 nm-30 nm, and the nanocrystalline diamond particles have a purity of more than or equal to 97%;
a process of depositing the diamond layer comprises:
placing the second copper/diamond sintered body with the nanocrystalline diamond
particles adsorbed on the surface of the second copper/diamond sintered body into a chemical vapor deposition furnace, and
carrying out a deposition by using CH4 as a carbon-containing gas and H2 as a diluent gas while controlling the carbon-containing gas to an amount of 0.5%-10.0% of a total gas mass flow in the chemical vapor deposition furnace, wherein the deposition is carried out at a temperature of 600° C.-1000° C. under a pressure of 103 Pa-104 Pa for 12 h-16 h; and a process of depositing the metal hydrophilic layer comprises:
placing the second copper/diamond sintered body with a diamond deposited on the surface of the second copper/diamond sintered body into a physical vapor deposition chamber, and
depositing a metal by a magnetron sputtering with a power of 100 W-300 W for 20 min-120 min, wherein the metal is selected from at least one of chromium, titanium, molybdenum, copper, tungsten, nickel, and cobalt.

9. A method for preparing the composite VC heat sink containing the copper/diamond composite wick structure according to claim 3 , comprising the following steps:
placing the second capillary wick in the upper shell plate,
carrying out a sintering to fix the

Assignees

• Univ Central South

Inventors

• Wei Qiuping
• Zhou Kechao
• Ma Li
• Wang Xi

Classifications

• H10W40/73

  for cooling by change of state · CPC title

• H10W40/257

  having a heterogeneous or anisotropic structure, e.g. powder or fibres in a matrix, wire mesh or porous structures (H10W40/254, H10W40/251 take precedence) · CPC title

• H10W40/254

  Diamond · CPC title

• F28F2255/18

  sintered · CPC title

• F28F2255/06

  composite, e.g. polymers with fillers or fibres · CPC title