CN102052864A - Temperature equalizing plate and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a temperature averaging plate and a manufacturing method thereof. The temperature averaging plate comprises a shell, a working fluid, a waterproof layer and a capillary structure layer. The working fluid is filled in the shell. The waterproof layer is formed on the inner wall of the shell. The capillary structure layer is formed on the waterproof layer.

Description

Vapor chamber and manufacturing method thereof

technical field

The invention relates to a heat dissipation device and a manufacturing method thereof, in particular to a uniform temperature plate which uses water as a working fluid and has a good heat dissipation effect and a manufacturing method thereof.

Background technique

In recent years, as the size of electronic devices has become thinner, lighter and smaller, the issue of heat dissipation of electronic devices has gradually received more attention. Among the many heat dissipation devices, the vapor chamber, also known as flat plate heat pipe, has been widely used in central processing units, graphics and display processing due to its excellent horizontal and vertical heat conduction characteristics. radiators, high-power transistors, high-power light-emitting diodes and other electronic devices to ensure that these electronic devices can operate under normal conditions without failure due to overheating.

Generally speaking, due to the advantages of light weight and low cost of aluminum, most traditional vapor chambers use aluminum alloy as their main material, especially in the aerospace industry, which uses aluminum vapor chambers as thermal management systems. One of the elements. Please refer to FIG. 1A , which is an exploded view of a traditional aluminum vapor chamber.

As shown in FIG. 1A , the vapor chamber 1 includes a plate body 10 , a first side plate 12 , a second side plate 14 and a filling pipe 16 . Wherein, the first side plate 12 is provided with a filling hole 120 and the plate body 10 is provided with a groove 100 . Vapor chamber 1 uses groove 100 (or aluminum mesh, stainless steel mesh) as a capillary structure, and is filled with a working fluid (such as acetone, refrigerant or liquid ammonia, etc.) that is chemically compatible with aluminum and does not react through the filling tube 16 into the uniform temperature plate 1.

Please refer to FIG. 1B , which is a cross-sectional view of a traditional aluminum vapor chamber. As shown in FIG. 1B , when the heat source is in contact with the bottom of the vapor chamber 1 , the above-mentioned contact area becomes a heating area. The liquid working fluid Fc absorbs the heat generated by the heat source Qin in the heating zone, evaporates into a gaseous working fluid Fh, and spreads to other areas inside the vapor chamber 1 . When the gaseous working fluid Fh contacts the cooling zone above the vapor chamber 1, the gaseous working fluid Fh releases its stored latent heat and condenses into a liquid working fluid Fc, the heat Qout dissipates from the cooling zone to the outside of the vapor chamber 1, and the liquid The working fluid Fc is guided back to the heating area by the capillary force provided by the capillary structure such as the groove 100 to complete a cycle process. Therefore, the traditional aluminum vapor chamber 1 uses the phase change of the working fluid between the liquid phase and the gas phase to achieve the effect of heat dissipation.

Please refer to FIG. 2 . FIG. 2 shows the heat transfer capability index curves of various working fluids at different temperatures. As shown in FIG. 2 , at the general operating temperature of electronic devices (30-100° C.), the heat transfer capability of water is significantly better than that of working fluids such as acetone, liquid ammonia, methanol, and ethanol.

However, since the surface of the aluminum vapor chamber will form a fine and chemically stable alumina layer, and the thermal expansion coefficients of the aluminum plate and the alumina layer are 23.1x10-6/K and 7x10-6/K, respectively, due to the difference between the two The difference between them is very large, and after many cycles of cold and heat, there will be fine cracks between the aluminum plate and the aluminum oxide layer. If the working fluid used in the vapor chamber is water, the water will seep into the cracks and react chemically with the aluminum, causing the vapor chamber to fail. Therefore, the traditional aluminum vapor chamber can only use A working fluid that is poor but does not react with aluminum, making it less effective at dissipating heat.

In addition, due to the fine and chemically stable aluminum oxide layer formed on the surface of the aluminum vapor chamber, the aluminum vapor chamber’s The surface cannot bond with other powdered metals. In addition, since the melting point of alumina is 2072°C and the sintering temperature is 1700°C, which is much higher than the melting point of aluminum at 660°C, it is also impossible to directly manufacture the capillary structure in the aluminum vapor chamber by powder sintering, resulting in the traditional aluminum Vapor chambers can only use mesh or grooved capillary structures. However, the heat flux of the grooved capillary structure is quite small, only up to 33W/cm ² , which is not suitable for heat dissipation of high-power transistors with large heat generation; as for the mesh-like capillary structure and uniform Poor lamination of the warming plate will lead to a substantial increase in the thermal resistance of the vapor chamber, which will seriously affect the heat dissipation effect of the vapor chamber.

Contents of the invention

Therefore, the object of the present invention is to propose a vapor chamber and its manufacturing method to solve the above problems.

According to one aspect of the present invention, a vapor chamber is provided. The uniform temperature plate includes a shell, a working fluid, a waterproof layer and a capillary structure layer. The working fluid is filled in the casing. A waterproof layer is formed on the inner wall of the case. A capillary structure layer is formed on the waterproof layer.

According to another aspect of the present invention, a method for manufacturing a vapor chamber is provided. In the manufacturing method, firstly, a casing is provided; then, a waterproof layer is formed on the inner wall of the casing; then, a capillary structure layer is formed on the waterproof layer; then, a working fluid is filled in the casing; finally, the casing is sealed .

Compared with the prior art, the vapor chamber and its manufacturing method proposed by the present invention, in addition to retaining the advantages of low cost and light weight of the traditional aluminum vapor chamber, can also be used in the The inner wall of the aluminum vapor chamber is sequentially formed with a waterproof layer and a powder-type porous capillary structure layer, so that the aluminum vapor chamber can use water with better heat transfer capacity at room temperature as its cooling working fluid for Greatly improve the heat dissipation effect of the aluminum vapor chamber. In addition, since the material forming the capillary structure layer is chemically compatible with water and does not react chemically with water, the surface of the capillary structure layer does not need to be coated with a waterproof layer, which reduces the overall thickness and saves material costs.

The advantages and spirit of the present invention can be further understood by using the following detailed description of the invention and the accompanying drawings.

Description of drawings

Figure 1A shows an exploded view of a conventional aluminum vapor chamber.

Figure 1B shows a cross-sectional view of a conventional aluminum vapor chamber.

FIG. 2 is a graph showing the heat transfer capability index curves corresponding to different working fluids at different temperatures.

Fig. 3 is an exploded view of a vapor chamber according to a specific embodiment of the present invention.

FIG. 4 is an external view of the base in FIG. 3 .

FIG. 5 is a cross-sectional view of the vapor chamber in FIG. 3 .

FIG. 6 shows an enlarged view of the region R in FIG. 5 .

Fig. 7 is a flowchart of a manufacturing method of a vapor chamber according to another specific embodiment of the present invention.

Detailed ways

A specific embodiment according to the present invention is a vapor chamber. In practical applications, the vapor chamber is used to cool electronic devices, and the material of the housing of the vapor chamber is a material that is chemically incompatible with water, such as aluminum, iron, or stainless steel. In addition, the above-mentioned vapor chamber uses water as its cooling working fluid to improve its heat transfer capability and reduce its thermal resistance.

Please refer to FIG. 3 , which is an exploded view of the above-mentioned temperature chamber according to this embodiment. As shown in FIG. 3 , the vapor chamber 2 includes an upper cover plate 20 , a base 21 , a first side plate 22 , a second side plate 24 , a filling tube 26 and a capillary structure layer 28 . In fact, the number of plates constituting the housing of the chamber 2 is not limited to the four (upper cover plate 20, base 21, first side plate 22, and second side plate 24) in this embodiment. It depends on the actual needs. Wherein, the first side plate 22 is provided with a filling hole 220 for filling water into the uniform temperature plate 2 through the filling pipe 26 . It should be noted that when the upper cover plate 20, the base 21, the first side plate 22, the second side plate 24 and the filling pipe 26 are assembled into the housing of the chamber 2, the An accommodating space is formed inside for accommodating water as a working fluid. Therefore, the capillary structure layer 28 (and the waterproof layer under it) is covered on the inner walls of all the accommodating spaces that may be in contact with water, that is, the upper cover plate 20, the base 21, the first side plate 22 and the second side plate are covered. The inner surface of the side plate 24 is shown in FIG. 3 .

In this embodiment, the base 21 is made by aluminum extrusion or die-casting, and the upper cover 20 , the first side plate 22 and the second side plate 24 are made by cold forging and stamping. In fact, the manufacturing methods of the upper cover plate 20, the first side plate 22 and the second side plate 24 are not limited to the above-mentioned forming methods such as aluminum extrusion, die-casting or cold forging stamping, and the base, the upper cover plate and the two side plates The material is not limited to aluminum materials such as pure aluminum or aluminum alloy, depending on actual needs.

As for FIG. 4 , it shows the appearance view of the base 21 of the independent temperature chamber 2 . As shown in FIG. 3 and FIG. 4 , the base 21 is provided with a plurality of support plates 210 , such as ribs as shown in FIG. 4 . The support plate 210 is supported between the base 21 and the upper cover plate 20 to strengthen the structure supporting the entire temperature chamber 2 . The number of support plates 210 and the positions thereof depend on actual needs and are not limited.

Please refer to FIG. 5 . FIG. 5 is a sectional view of the temperature chamber in FIG. 3 , that is, a sectional view of the assembled temperature chamber 2 . As shown in Figure 5, the inner walls of the housing space S forming the chamber 2 (that is, the inner surfaces of the upper cover plate 20, the base 21 and the support plate 210) are all covered with a waterproof layer 29, and are waterproof Layer 29 is also covered with capillary structure layer 28 . In this embodiment, the waterproof layer 29 and the capillary structure layer 28 are sequentially formed on all the upper cover plate 20, the base 21, the first side plate 22 and the second side plate 24 that may be in contact with water on the inner surface, but not limited thereto.

In practical applications, the melt spraying molding method can be different forms of melt spraying molding methods such as plasma melting spraying, arc melting spraying, flame melting spraying or high-speed flame melting spraying, and It can be carried out under high temperature or low temperature environment without certain limitation. It should be noted that, the spray coating material used in the above-mentioned spray spray molding method is a metal or ceramic material that is chemically compatible with the working fluid in the vapor chamber 2 and does not react. In this embodiment, since the vapor chamber 2 uses water as the working fluid, the above-mentioned spray spray molding method uses a spray coating material that is chemically compatible with water and does not react, such as copper, brass, nickel Materials such as titanium or titanium are used as spraying materials for forming the waterproof layer 29 and the capillary structure layer 28, but not limited thereto.

In this embodiment, the spraying material forming the waterproof layer 29 is first melted into a liquid state, and then blown out into powder particles with a diameter of 5 to 200 nanometers by high-pressure gas, and sprayed and stacked on all the upper cover plates that may be in contact with water at high speed. 20. A waterproof layer 29 with a thickness of about 10 to 50 microns is formed on the inner surfaces of the base 21 , the first side panel 22 and the second side panel 24 . Similarly, the spraying material forming the capillary structure layer 28 is first melted into a liquid state, and then blown into powder particles with a diameter of 35 to 250 microns by high-pressure gas and sprayed at a high speed to stack on the surface of the waterproof layer 29, forming a thickness of about 0.1 to 250 microns. A powdery porous capillary structure layer 28 of 0.8 mm.

Please refer to FIG. 6 , which is an enlarged view of the region R in FIG. 5 . As shown in Figure 6, the thickness of the waterproof layer 29 formed on the base 21 is much smaller than the thickness of the capillary structure layer 28 formed on the waterproof layer 29, and the size of the powder particles 290 forming the waterproof layer 29 is much smaller than that of the capillary structure layer 28. The powder particles are 280 in size. In addition, since the porosity of the capillary structure layer 28 is approximately between 30% and 70%, which is much greater than the porosity of the waterproof layer 29 which is less than or equal to 2%, the capillary structure layer 28 has porosity, and the waterproof layer 29 can Effectively prevent water from reacting with the aluminum base 21 under the waterproof layer 29 .

In practical applications, the sprayed materials forming the waterproof layer 29 and the capillary structure layer 28 can be the same material (for example, both are copper), or different materials (for example, nickel and brass respectively), and there is no certain limit, but It is better to use the same material.

Another specific embodiment according to the present invention is a method for manufacturing a vapor chamber. In practical application, the vapor chamber manufactured by the above vapor chamber manufacturing method is applied to the cooling of electronic devices, and the material of the shell of the above vapor chamber is aluminum, iron or stainless steel, etc., which are chemically incompatible with water. Materials, ie those mentioned above, have the opportunity to react with water and cause failure or reduced effectiveness. In addition, the above-mentioned vapor chamber uses water as its cooling working fluid to improve its heat transfer capability and reduce its thermal resistance.

Please refer to FIG. 7 , which is a flow chart of the method for manufacturing the above-mentioned vapor chamber. As shown in FIG. 7 , firstly, steps S10 and S11 are performed respectively, the base is made by aluminum extrusion or die-casting method, and the upper cover plate and two side plates are made by cold forging and stamping method. In this embodiment, the base, the upper cover and the side panels are made of traditional aluminum materials such as pure aluminum or aluminum alloy.

In fact, the manufacturing methods of the base, upper cover and side panels are not limited to the above-mentioned forming methods such as aluminum extrusion, die-casting or cold forging stamping, and the materials of the base, upper cover and side panels are not limited to pure Aluminum materials such as aluminum or aluminum alloy, depending on actual needs. In addition, the base can also be provided with a plurality of support plates. When the base, the upper cover, the first side plate and the second side plate are assembled, these support plates can be held between the base and the upper cover for The interior of the chamber of the chamber is divided into multiple accommodation spaces, and the structure supporting the chamber can be strengthened. As for the number of the support boards and their positions, they can be determined according to actual needs.

Next, step S12 is executed to perform sandblasting roughening on the surface in contact with the working fluid (ie water). The purpose of performing the above step S12 in the above vapor chamber manufacturing method is to perform sandblasting or other roughening procedures on the surfaces of the base, the upper cover plate and the two side plates that may be in contact with the working fluid in advance, so as to Increasing the roughness of the above-mentioned surfaces makes the adhesion of the spraying material subsequently sprayed on the above-mentioned surfaces stronger. Then, step S13 is executed to perform ultrasonic cleaning and degreasing on the above-mentioned surfaces, so as to facilitate the subsequent spraying process.

Next, step S14 is executed to form a copper waterproof layer on the above-mentioned surfaces in contact with the working fluid by a melt-spraying overmolding method. In practical applications, the melt spraying molding method can be different forms of melt spraying molding methods such as plasma melting spraying, arc melting spraying, flame melting spraying or high-speed flame melting spraying, and It can be carried out at high temperature or low temperature without certain limitation.

It is worth noting that in step S14, the spray coating material used in the above-mentioned spray coating molding method is a metal or ceramic material that is chemically compatible with the working fluid in the vapor chamber and does not react. Since the present invention uses water as the working fluid in the vapor chamber, the above-mentioned spray spray molding method uses materials that are chemically compatible with water and do not react, such as copper, brass, nickel or titanium. Spraying material for waterproof layer. In step S14, the spraying material is first melted into a liquid state, and then blown into powder particles with a diameter of 5 to 200 nanometers by high-pressure gas, and sprayed and stacked on the above-mentioned surfaces in contact with the working fluid at a high speed, forming a thickness of about 10 to 200 nanometers. 50 micron waterproof layer.

Next, step S15 is performed to form a copper porous capillary structure layer on the above copper waterproof layers by means of melt spraying. Similar to step S14, the melt spraying molding method used in step S15 can also be different forms of melt spraying such as plasma melt spraying, arc melt spraying, flame melt spraying or high-speed flame spraying. Spray molding method, and can be carried out in high temperature or low temperature environment without certain restrictions. In addition, the spray coating molding method in step S15 also uses materials that are chemically compatible with water and do not react, such as copper, brass, nickel or titanium, as the coating material for the capillary structure layer.

It is worth noting that the spraying materials used in step S14 and step S15 can be the same material (for example, the spraying materials forming the waterproof layer and the capillary structure layer are all copper), or different materials (for example, the spraying materials forming the waterproof layer The coating material is titanium, and the spray coating material forming the capillary structure layer is copper), there is no certain limitation, but the same material is preferred.

In step S15, the spraying material is first melted into a liquid state, and then blown into powder particles with a diameter of 35 to 250 microns by high-pressure gas, and sprayed and stacked on the surface of the above-mentioned waterproof layers at a high speed, forming a thickness of about 0.1 to 0.8 mm. Powder type porous capillary structure layer. Comparing steps S14 and S15, it can be seen that although both the waterproof layer and the capillary structure layer are formed by the melt spraying spray molding method, the thickness of the capillary structure layer is much larger than the thickness of the waterproof layer, and the powder particle size of the sprayed and stacked capillary structure layer It is also much larger than the particle size of the powder that is sprayed and stacked to form a waterproof layer. As for the porosity of the above-mentioned capillary structure layer between about 30% and 70%, it is much larger than the porosity of the waterproof layer less than or equal to 2%, so the above-mentioned capillary structure layer has porosity, and the waterproof layer can effectively avoid water and waterproofing. The aluminum vapor chamber below the layer is in contact to generate the reaction.

Afterwards, steps S16 and S17 are executed sequentially. Firstly, the base, the upper cover plate and the two side plates are assembled into the chamber shell, and then the chamber shell is sealed by laser welding or plasma arc welding. Since an airtight accommodating space has been formed inside the housing of the chamber at this time, step S18 may be performed to fill the accommodating space with the working fluid (ie water). In practical applications, the uniform temperature plate may be further provided with a filling pipe on one side plate to facilitate the filling of the working fluid. Finally, steps S19 and S20 are executed in sequence, and the vapor chamber is vacuumed and degassed to seal the chamber respectively, and the performance test and dimension inspection of the chamber are performed, and the entire chamber manufacturing process is completed.

In summary, compared with the prior art, the vapor chamber and its manufacturing method proposed by the present invention can not only retain the advantages of low cost and light weight of the traditional aluminum vapor chamber, but also can Injection spray coating technology sequentially forms a waterproof layer and a powder-type porous capillary structure layer on the inner wall of the aluminum vapor chamber, so that the aluminum vapor chamber can use water with better heat transfer capacity at room temperature as its cooling work Fluid, used to greatly improve the heat dissipation effect of the aluminum vapor chamber. In addition, since the material forming the capillary structure layer is chemically compatible with water and will not react chemically with water, the surface of the capillary structure layer does not need to be coated with a waterproof layer, which reduces the overall thickness and saves material costs.

With 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 protection scope of the present invention is not limited by the preferred embodiments disclosed above. On the contrary, the intention is to cover various modifications and equivalent arrangements within the scope of the invention as defined by the appended claims.

Claims (25)

1. A vapor chamber, characterized in that it comprises: case; working fluid, filled in the housing; a waterproof layer formed on the inner wall of the housing; and The capillary structure layer is formed on the waterproof layer. 2. The vapor chamber according to claim 1, wherein the working fluid is water. 3. The vapor chamber according to claim 2, characterized in that, the waterproof layer and the capillary structure layer are materials that do not react with water, and the materials are selected from copper, brass, nickel and titanium materials. composed of groups. 4. The temperature chamber according to claim 1, characterized in that, the capillary structure layer is a powder-type porous capillary structure layer. 5. The temperature chamber according to claim 1, characterized in that, the thickness of the capillary structure layer is greater than the thickness of the waterproof layer. 6. The temperature chamber according to claim 1, wherein the porosity of the waterproof layer is less than or equal to 2%. 7. The temperature chamber according to claim 1, wherein the porosity of the capillary structure layer is between 30% and 70%. 8 . The temperature chamber according to claim 1 , wherein the housing is composed of a base, an upper cover, a first side plate and a second side plate. 9. The chamber according to claim 8, wherein the chamber further comprises: A plurality of supporting boards are supported between the base and the upper cover. 10 . The temperature chamber according to claim 9 , characterized in that, the waterproof layer and the capillary structure layer are sequentially provided on the support plates. 11 . 11 . The temperature chamber according to claim 1 , wherein the material of the casing is a metal material selected from the group consisting of aluminum, iron and stainless steel. 12 . The temperature chamber according to claim 1 , wherein the waterproof layer and the capillary structure layer are sequentially formed on the inner wall of the casing by a melt-jet spray molding method. 13 . 13. A method for manufacturing a vapor chamber, characterized by comprising the following steps: provide housing; forming a waterproof layer on the inner wall of the casing; forming a capillary structure layer on the waterproof layer; filling the housing with working fluid; and The housing is sealed. 14 . The method for manufacturing a temperature chamber according to claim 13 , wherein the housing is composed of a base, an upper cover, a first side plate and a second side plate. 15 . 15. The method for manufacturing a temperature chamber according to claim 14, wherein the waterproof layer and the capillary structure layer are formed on the base, the upper cover, the first side plate and the on the second side. 16. The method for manufacturing a vapor chamber according to claim 15, further comprising the following steps: The base, the upper cover, the first side plate and the second side plate are assembled into the casing. 17. The method for manufacturing a vapor chamber according to claim 13, wherein the working fluid is water. 18. The method for manufacturing a vapor chamber according to claim 17, wherein the waterproof layer and the capillary structure layer are materials that do not react with water, and the materials are selected from copper, brass, nickel and titanium A group of materials. 19. The method for manufacturing a vapor chamber according to claim 13, wherein the capillary structure layer is a powder-type porous capillary structure layer. 20. The method for manufacturing a temperature chamber according to claim 13, wherein the thickness of the capillary structure layer is greater than the thickness of the waterproof layer. 21. The method for manufacturing a temperature chamber according to claim 13, wherein the porosity of the waterproof layer is less than or equal to 2%. 22. The method for manufacturing a vapor chamber according to claim 13, wherein the porosity of the capillary structure layer is between 30% and 70%. 23. The method for manufacturing a temperature chamber according to claim 13, wherein the base, the upper cover, the first side plate and the second side plate are made of metal materials, and the materials are selected Group consisting of free aluminum, iron and stainless steel materials. 24. The method for manufacturing a temperature chamber according to claim 13, wherein the waterproof layer is formed on the base, the upper cover, the first side plate and the second side plate Said steps are accomplished via melt-spray overmolding. 25 . The method for manufacturing a temperature chamber according to claim 13 , wherein the step of forming the capillary structure layer on the waterproof layer is completed by a spray-on-molding method. 26 .

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