WO2021042946A1

WO2021042946A1 - Metal oxide slurry for making capillary structure of uniform temperature plate element

Info

Publication number: WO2021042946A1
Application number: PCT/CN2020/108393
Authority: WO
Inventors: 陈振贤
Original assignee: 广州力及热管理科技有限公司
Priority date: 2019-09-03
Filing date: 2020-08-11
Publication date: 2021-03-11
Also published as: CN112444151B; TWI781431B; CN112444151A; TW202110773A

Abstract

Provided is a metal oxide slurry for making capillary structure of uniform temperature plate element, comprising cuprous oxide powder, polymer and organic solvent. The colloid formed by mixing the polymer and the organic solvent can be used to uniformly disperse, suspend and mix the cuprous oxide powder to form the metal oxide slurry. Wherein, the metal oxide slurry can volatilize the organic solvent through the heating process, and burn off the polymer through the baking process. The metal oxide slurry is laid in a groove of a metal substrate by steel plate printing, screen printing or glue dispensing to make the capillary structure of the uniform temperature plate, using the metal oxide slurry to make the capillary structure can increase the mass production efficiency of the uniform temperature plate and improve the mass production yield of the uniform temperature plate product.

Description

Metal oxide slurry for making capillary structure of uniform temperature plate element

Technical field

A metal oxide slurry, especially a metal oxide slurry with a continuous and porous capillary structure used in the production of a vapor chamber.

Background technique

The conventional vapor chamber manufacturing method is to etch a sheet-shaped copper substrate, and then lay a copper screen mesh or woven mesh (Copper Woven Mesh) on the copper substrate, and then press and combine it with a graphite jig. The capillary structure is formed on the groove surface of the copper sheet substrate by sintering at a high temperature, and then the copper sheet substrate with the groove is welded together in a groove-in-the-groove manner to form an air passage cavity. After further processing such as sealing, water injection, vacuuming, etc., a Vapor Chamber or Heat Pipe Plate with a capillary structure is made.

The screen mesh material used as the capillary structure of the uniform temperature plate is a large copper mesh woven with thin copper wires. In actual application, it must be cut into a suitable shape and size according to the designed shape and size of the uniform temperature plate or plate heat pipe before it can be laid in the groove on the surface of the copper substrate. In order to make the copper mesh with a thickness of less than 100 microns (100um) flattened and fixed on the copper substrates of different shapes and sizes, it is necessary to perform high-temperature sintering (Sintering) after pressing with a tool. As the general screen mesh only cross-weaves, the capillary structure is simple, resulting in insufficient capillary force. Therefore, the Copper Move Mesh with a complex weaving structure has become a choice for enhancing capillary force. Still, the processes of weaving, cutting, manual laying of copper mesh, and pressing of graphite fixtures make the production of the capillary structure of the uniform temperature plate complicated and unfavorable for automated operations in mass production.

Summary of the invention

In view of this, the purpose of the present invention is to provide a metal oxide slurry, which is used to make the capillary structure of the uniform temperature plate element to replace the conventional copper mesh and woven mesh material, which is used to make the capillary structure and is used for heating The capillary structure is formed after baking and sintering process. The metal oxide paste of the present invention can be used to lay the material in an automated printing method and form a continuous porous capillary structure by the reduction and diffusion reaction of the cuprous oxide crystal powder during sintering, thereby eliminating the need for cutting conventional copper meshes. Cutting and manual meshing operations, and can save the mold and mold pressing and fixing process in the sintering process.

In order to achieve the above object, the present invention discloses a metal oxide slurry, which is applied to the production of a capillary structure in a uniform temperature plate, and the capillary structure is formed after heating, baking and sintering processes, and is characterized in that it includes:

Cuprous oxide powder;

An organic solvent, which evaporates after heating; and

A polymer, burned off after baking;

Wherein, the organic solvent is mixed with the polymer to form a colloid for dispersing, suspending and uniformly mixing the cuprous oxide powder to form the metal oxide slurry.

Wherein, the metal oxide paste has rheological properties, and it is laid on a groove of a metal substrate used to make the uniform temperature plate by means of steel plate printing, screen printing, glue dispensing or direct squeegee printing. in.

Wherein, the cuprous oxide powder has an octahedral crystal structure and is sintered in a hydrogen-containing atmosphere. After reduction and diffusion reactions, the cuprous oxide powder forms a plurality of interconnected chain-like copper components, and then forms a continuous and Porous capillary structure.

Wherein, the average particle size of the cuprous oxide powder is less than 3 microns, and the average chain diameter of the plurality of chain-shaped copper members is less than 3 microns.

Among them, a copper powder is further doped, and the average particle size (D50) of the copper powder is in the range of 3-53um.

Wherein, the cuprous oxide powder is sintered in a hydrogen-containing atmosphere, and through reduction and diffusion reactions, the cuprous oxide powder forms a plurality of chain-shaped copper members connected to each other, and the plurality of chain-shaped copper members are connected to each other to form a chain shape Or a net-like shape between a plurality of spherical-like copper members formed by the copper powder.

Wherein, the metallic copper powder is a spherical particle, and is uniformly mixed in the colloid together with the cuprous oxide powder.

Wherein, the metallic copper powder is used to adjust the porosity in the capillary structure.

It can be seen from the above that, compared to the conventional metal copper mesh laying, pressing and sintering technology applied to the capillary structure in the Vapor Chamber, the metal oxide paste of the present invention can be directly printed and further sintered. Furthermore, a capillary structure composed of a chain-like metal copper member is formed. In addition, the branched metal oxide slurry of the present invention can further adjust the porosity in the capillary structure by doping metal copper powder in the metal oxide slurry.

Description of the drawings

Fig. 1 is a schematic diagram of the mixing of metal oxide slurry according to a specific embodiment of the present invention.

Fig. 2 is a schematic diagram of the composition of a metal oxide slurry according to a specific embodiment of the present invention.

Fig. 3 is a schematic diagram of the composition of a metal oxide slurry according to another embodiment of the present invention.

4A, 4B, and 4C are schematic diagrams of the appearance of a chain-shaped copper component formed by a reduction and diffusion reaction of a single cuprous oxide crystal powder during a sintering process according to a specific embodiment of the present invention.

Fig. 5 is a schematic diagram of a capillary structure formed after sintering a metal oxide slurry according to a specific embodiment of the present invention.

Fig. 6 is a schematic diagram of a capillary structure formed after sintering a metal oxide slurry according to another embodiment of the present invention.

detailed description

In order to make the advantages, spirit and characteristics of the present invention easier and clearer to understand, the following will use specific embodiments and refer to the accompanying drawings for detailed and discussion. It should be noted that these specific embodiments are only representative specific embodiments of the present invention, and the specific methods, devices, conditions, materials, etc. exemplified therein are not intended to limit the present invention or the corresponding specific embodiments. In addition, each device in the figure is only used to express its relative position and is not drawn according to its actual scale, which is described first.

Please refer to FIGS. 1 to 2. FIG. 1 is a schematic diagram of the mixing of the metal oxide paste 1 according to a specific embodiment of the present invention, and FIG. 2 is the composition of the metal oxide paste 1 according to a specific embodiment of the present invention Schematic. As shown in FIGS. 1 and 2, the metal oxide slurry 1 includes cuprous oxide powder 12 (Cu ₂ O Powder), an organic solvent 13 and a polymer 14. The organic solvent 13 may be an alcohol, which volatilizes when heated, and the polymer 14 may be a resin, which will be burned out after baking. Among them, the organic solvent 13 is mixed with the polymer 14 to form a colloid 15 (Colloid), and the cuprous oxide powder 12 is dispersed, suspended and uniformly mixed in the colloid 15. The content of the cuprous oxide powder 12 and the solid content (Solid Content) of the metal oxide slurry 1 depend on the thickness requirements of the capillary structure layer of the uniform temperature plate made by the metal oxide slurry 1. In a specific embodiment, the solid content of the metal oxide slurry 1 is between 30% and 70%.

Please refer to FIG. 3, which is a schematic diagram of the composition of a metal oxide slurry according to another embodiment of the present invention. As shown in FIG. 3, the cuprous oxide powder 12 has an octahedral crystal structure. The particle size range of the cuprous oxide powder 12 is less than 3um.

In the embodiment of FIG. 3, the metal oxide slurry 1 of the present invention is further doped with copper powder 11 (Cu Powder), which is spherical-like particles, and is uniformly mixed with the cuprous oxide powder 12 in the colloid 15 . The function of the copper powder is to adjust the porosity in the capillary structure. In a specific embodiment, the average particle size of the copper powder 11 ranges from 3 μm to 53 μm.

Please refer to FIGS. 4A, 4B, and 4C. FIGS. 4A, 4B, and 4C are schematic diagrams of the appearance change of a single cuprous oxide powder 12 during a sintering process according to a specific embodiment of the present invention. The cuprous oxide powder 12 Sintering in a hydrogen-containing atmosphere and simultaneous reduction and diffusion reactions, the rhombohedral octahedral crystals of the cuprous oxide powder 12 are reduced and diffused along the two tips, and then stretched into a chain-shaped copper member 22.

Please refer to FIG. 5. FIG. 5 is a schematic diagram of a capillary structure 2 formed after sintering the metal oxide slurry 1 according to a specific embodiment of the present invention. The chain-shaped copper members 22 are sintered to be connected to each other to form a three-dimensional porous capillary structure 2, and are sintered to bond with the upper surface of the groove of the supported metal substrate.

As shown in FIG. 5, in a specific embodiment, when the metal oxide slurry is heated, the organic solvent in the colloid will be completely volatilized due to the low boiling point. Then, increase the temperature for baking, the polymer in the colloid will be further burned and removed, leaving only the cuprous oxide powder. Then, a higher temperature sintering process is performed in a hydrogen-containing atmosphere, and the cuprous oxide powder undergoes reduction and diffusion reactions at the same time, and is connected to each other to form a three-dimensional porous capillary structure 2.

Please refer to FIG. 6, which is a schematic diagram of a capillary structure 2 formed after sintering a metal oxide slurry according to another embodiment of the present invention. The embodiment of FIG. 6 is different from the embodiment of FIG. 5 in that the metal oxide slurry is doped with copper powder, so when the polymer in the colloid is burned out, a mixture of cuprous oxide powder and copper powder will remain The structure is further sintered in a hydrogen-containing atmosphere to form a mixed capillary structure 2 of the chain-shaped copper member 22 and the spherical copper member 21.

In practical applications, the rhombohedral octahedral cuprous oxide powder in the metal oxide slurry is transformed into a long chain-shaped copper member through the sintering process, which is the basic element of the overall capillary structure of the framework. The copper powder doped in the metal oxide slurry is evenly distributed in the chain-shaped copper component after sintering. In a specific embodiment, the copper powder is a spherical powder with an average particle size between 3um and 53um. The function of the copper powder is to adjust the porosity in the capillary structure. In a specific embodiment, the proportion of copper powder doping in the metal oxide slurry will affect the distribution density of the spherical metal components in the capillary structure, and then affect the porosity and the capillary of the working fluid in the uniform temperature plate. force.

Compared with the conventional metal copper mesh laying and pressing sintering technology applied to the capillary structure in the Vapor Chamber, the metal oxide slurry of the present invention has rheology, and is implemented in specific applications. In the example, it can be laid in the grooves of the metal substrate used to make the uniform temperature plate by using Stencil Printing, Screen Printing, Dispense, or direct squeegee printing.

The metal oxide slurry of the present invention can make the capillary structure 2 formed by the metal oxide slurry of the present invention have better porosity and uniform pore size due to the physical and chemical properties of the cuprous oxide powder 12. In turn, the capillary function of the capillary structure is improved. Furthermore, the paste is laid in the grooves of the sheet-shaped copper metal substrate by printing, and the thickness of the capillary structure after sintering is controlled by the solid content of the paste. Since the particle size of the cuprous oxide crystals is small (<3um) and uniformly distributed, the chain forming the chain-shaped copper metal structure is not more than 3um, so the use of the metal oxide slurry of the present invention can effectively control the capillary structure of the uniform temperature plate Below 50 microns (50um), this is helpful for mass production of ultra-thin Vapor Chamber or Heat Pipe Plate with a thickness of only 3 mm (3mm).

Based on the above detailed description of the preferred embodiments, it is hoped that the characteristics and spirit of the present invention can be described more clearly, and the scope of the present invention is not limited by the preferred embodiments disclosed above. On the contrary, the purpose is to cover various changes and equivalent arrangements within the scope of the patent application for the present invention. Therefore, the scope of the patent application for the present invention should be interpreted in the broadest way based on the above description, so that it covers all possible changes and equivalent arrangements.

Claims

A metal oxide slurry is applied to the production of a capillary structure in a uniform temperature plate, and the capillary structure is formed after the processes of heating, baking and sintering, and is characterized in that it contains:

Cuprous oxide powder;

An organic solvent, which evaporates after heating; and

A polymer, burned off after baking;

Wherein, the organic solvent is mixed with the polymer to form a colloid for dispersing, suspending and uniformly mixing the cuprous oxide powder to form the metal oxide slurry.
The metal oxide paste of claim 1, wherein the metal oxide paste has rheological properties, and is laid on the surface by means of steel plate printing, screen printing, glue dispensing or direct scratch printing. Used to make a groove of a metal substrate of the uniform temperature plate.
The metal oxide slurry of claim 1, wherein the cuprous oxide powder has an octahedral crystal structure and is sintered in a hydrogen-containing atmosphere. After reduction and diffusion reactions, the cuprous oxide powder is formed The multiple chain-shaped copper members connected to each other further form a continuous and porous capillary structure.
3. The metal oxide slurry of claim 3, wherein the average particle size of the cuprous oxide powder is less than 3 microns, and the average chain diameter of the plurality of chain-shaped copper members is less than 3 microns.
The metal oxide slurry of claim 1, wherein a copper powder is further doped, and the average particle size (D50) of the copper powder is in the range of 3-53um.
The metal oxide slurry of claim 5, wherein the cuprous oxide powder is sintered in a hydrogen-containing atmosphere, and through reduction and diffusion reactions, the cuprous oxide powder forms a plurality of interconnected copper chains. A member in which the plurality of chain-shaped copper members are connected to each other to form a chain or a net shape between the plurality of spherical copper members formed by the copper powder.
7. The metal oxide slurry of claim 5, wherein the metallic copper powder is spherical particles, and is uniformly mixed with the cuprous oxide powder in the colloid.
5. The metal oxide slurry of claim 5, wherein the metal copper powder is used to adjust the porosity in the capillary structure.