Corrosion-resistant liquid cooling plate and preparation method thereof

Abstract

The invention provides a corrosion-resistant liquid cooling plate and a preparation method thereof. The cold plate comprises a bottom plate and a cover plate which are connected with each other, the end face, facing the cover plate, of the bottom plate is provided with a runner structure. A corrosion-resistant coating is arranged on the surface of the runner structure; the corrosion-resistant coating comprises one or more of nano aluminum nitride powder, nano diamond powder, titanium dioxide powder and modified organic silicon high-temperature-resistant resin; one of the two opposite ends of the flow channel structure is a water inlet, and the other is a water outlet. It can be seen that according to the corrosion-resistant liquid cooling plate provided by the invention, the corrosion-resistant coating is arranged on the surface of the flow channel structure, and the flow channel structure is not prone to electrochemical corrosion, so that the corrosion resistance of the cold plate is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of cold plates, and in particular relates to a corrosion-resistant liquid cold plate and a preparation method thereof. Background Art

[0002] Liquid cooling plate is a type of indirect liquid cooling method. The coolant does not directly contact the heat source. It is widely used in 5G communications, new energy vehicles, power electronics and other scenarios. In the process of realizing the invention, the inventor found that there are at least the following problems in the prior art: due to the presence of a small amount of impurity elements in the coolant, the metal cold plate will undergo a certain degree of electrochemical corrosion after long-term operation, which may lead to the risk of cold plate leakage and water pipe blockage, and then cause the cooling system to fail, leading to overheating of electronic components and other problems. Therefore, how to improve the corrosion resistance of the cold plate has become a research hotspot. Summary of the invention

[0003] In view of this, an object of the present invention is to provide a corrosion-resistant liquid cooling plate and a preparation method thereof, which can improve the corrosion resistance of the cooling plate.

[0004] The present invention provides a corrosion-resistant liquid cooling plate, comprising a base plate and a cover plate connected to each other;

[0005] The end surface of the bottom plate facing the cover plate is provided with a flow channel structure;

[0006] The surface of the flow channel structure is provided with a corrosion-resistant coating;

[0007] The corrosion-resistant coating comprises one or more of nano-aluminum nitride powder, nano-diamond powder, titanium dioxide powder and modified organic silicon high temperature resistant resin;

[0008] One of the two opposite ends of the flow channel structure is a water inlet, and the other is a water outlet.

[0009] In certain specific embodiments of the present invention, the thickness of the corrosion-resistant coating is 30 to 50 μm.

[0010] In certain specific embodiments of the present invention, the water inlet is a water inlet threaded port;

[0011] The water outlet is a water outlet threaded port.

[0012] In certain specific embodiments of the present invention, the flow channel structure is divided by spacers to form a tortuous flow channel.

[0013] In certain specific embodiments of the present invention, the thermal conductivity of the corrosion-resistant coating is 20 to 60 W / (mk).

[0014] In certain specific embodiments of the present invention, the base plate and / or cover plate is an aluminum alloy plate.

[0015] In some specific embodiments of the present invention, the bottom plate and the cover plate are sealed and connected by solder;

[0016] The solder is selected from one or more of Sn-Zn-Ge, Sn-Pb-Ag and Pb-Bi-Ag.

[0017] The present invention also provides a method for preparing a corrosion-resistant liquid cooling plate, comprising the following steps:

[0018] Processing a flow channel structure, a water inlet and a water outlet on the plate to obtain a bottom plate;

[0019] A corrosion-resistant coating is prepared on the surface of the flow channel structure, the bottom plate and the cover plate that are in direct contact with the coolant, wherein the corrosion-resistant coating comprises one or more of nano-aluminum nitride powder, nano-diamond powder, titanium dioxide powder and modified organic silicon high temperature resistant resin;

[0020] The bottom plate and the cover plate are sealed and connected by a low-temperature brazing process to obtain a corrosion-resistant liquid cooling plate.

[0021] In certain specific embodiments of the present invention, the corrosion-resistant coating is prepared by brushing, spraying or micro-arc oxidation.

[0022] In certain specific embodiments of the present invention, the brazing material used for brazing is selected from one or more of Sn-Zn-Ge, Sn-Pb-Ag and Pb-Bi-Ag;

[0023] The brazing temperature is below 300°C.

[0024] Compared with the prior art, the corrosion-resistant liquid cooling plate and the preparation method thereof provided by the present invention have at least the following beneficial effects:

[0025] The present invention provides a corrosion-resistant liquid cooling plate, comprising a bottom plate and a cover plate connected to each other; a flow channel structure is provided on the end surface of the bottom plate facing the cover plate; a corrosion-resistant coating is provided on the surface of the flow channel structure; the corrosion-resistant coating comprises one or more of nano-aluminum nitride powder, nano-diamond powder, titanium dioxide powder and modified organic silicon high temperature resistant resin; one of the two opposite ends of the flow channel structure is a water inlet and the other is a water outlet. It can be seen that the corrosion-resistant liquid cooling plate provided by the present invention is provided with a corrosion-resistant coating on the surface of the flow channel structure, and the flow channel structure is less susceptible to electrochemical corrosion, thereby improving the corrosion resistance of the cold plate.

[0026] The method for preparing the corrosion-resistant liquid cooling plate provided by the present invention can manufacture a cooling plate having the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of the corrosion-resistant liquid cooling plate in the present invention, wherein 1 is a bottom plate, 2 is a water inlet, 3 is a flow channel structure, and 4 is a cover plate;

[0028] Figure 2 A schematic diagram of the process for preparing a corrosion-resistant liquid cooling plate provided by the present invention. DETAILED DESCRIPTION

[0029] The present invention provides a corrosion-resistant liquid cooling plate, comprising a base plate and a cover plate connected to each other;

[0030] The end surface of the bottom plate facing the cover plate is provided with a flow channel structure;

[0031] The surface of the flow channel structure is provided with a corrosion-resistant coating;

[0032] The corrosion-resistant coating comprises one or more of nano-aluminum nitride powder, nano-diamond powder, titanium dioxide powder and modified organic silicon high temperature resistant resin;

[0033] One of the two opposite ends of the flow channel structure is a water inlet, and the other is a water outlet.

[0034] See also Figure 1 , Figure 1 Schematic diagram of the structure of the corrosion-resistant liquid cooling plate in the present invention, wherein 1 is a bottom plate, 2 is a water inlet, 3 is a flow channel structure, and 4 is a cover plate.

[0035] The corrosion-resistant liquid cooling plate provided by the present invention provides a specific type of corrosion-resistant coating on the surface of the flow channel structure, so that the flow channel structure is less susceptible to electrochemical corrosion, thereby improving the corrosion resistance of the cooling plate.

[0036] The corrosion-resistant liquid cooling plate provided by the present invention comprises a bottom plate and a cover plate connected to each other; the bottom plate is provided with a flow channel structure on the end surface facing the cover plate; the flow channel structure is separated by spacers to form a circuitous flow channel. When the bottom plate and the cover plate are connected together, a flow channel with a water inlet and outlet can be enclosed.

[0037] The base plate and the cover plate of the present invention are sealed and connected by solder; the solder is selected from one or more of Sn-Zn-Ge, Sn-Pb-Ag and Pb-Bi-Ag. The above solders can be welded at a relatively low temperature (<300°C), greatly reducing the risk of cracking and falling off of the ceramic coating prepared under high-temperature brazing, and the coating has a longer service life.

[0038] In the specific embodiment of the present invention, the bottom plate and / or cover plate can be made of aluminum alloy plate. It is understandable that the bottom plate and the cover plate are preferably made of the same metal material, which is conducive to avoiding electrochemical corrosion between different metal materials. It should be noted that the bottom plate and the cover plate can also be made of other metal / alloy plates with good thermal conductivity, such as copper plates.

[0039] The two opposite ends of the flow channel structure of the corrosion-resistant liquid cooling plate provided by the present invention are a water inlet and a water outlet. The water inlet is a water inlet threaded port; the water outlet is a water outlet threaded port; it is convenient to connect with the water pipe quick connector later.

[0040] The surface of the flow channel structure in the corrosion-resistant liquid cooling plate provided by the present invention is provided with a corrosion-resistant coating; the corrosion-resistant coating includes one or more of nano aluminum nitride powder, nano diamond powder, titanium dioxide powder and modified silicone high temperature resistant resin, more preferably one or more of aluminum nitride powder with a particle size of 0.5 to 5 μm, diamond powder with a particle size of 0.5 to 5 μm, titanium dioxide powder with a particle size of 0.5 to 5 μm and modified silicone high temperature resistant resin; the above-mentioned types of corrosion-resistant coatings are formed on the surface of the flow channel structure by brushing, spraying or micro-arc oxidation, and are uniform, dense and have a high thermal conductivity. The thermal conductivity of the corrosion-resistant coating is 20 to 60 W / (mk); specifically 20 W / (mk), 25 W / (mk) or 60 W / (mk). The thickness of the corrosion-resistant coating is 30 to 50 μm; specifically 30 μm, 35 μm, 40 μm, 45 μm or 50 μm.

[0041] The modified organic silicon high temperature resistant resin in the present invention is a polyimide modified organic silicon high temperature resistant resin. The corrosion resistant coating specifically comprises a composite powder of 0.5-5 μm diamond powder and aluminum nitride powder in a mass ratio of (5-20):20, and a polyimide modified organic silicon high temperature resistant resin, wherein the mass ratio of diamond powder to aluminum nitride powder in the composite powder is 2:1; or the corrosion resistant coating specifically comprises a composite powder of aluminum nitride powder and titanium dioxide in a mass ratio of 2:1; or the corrosion resistant coating specifically is an aluminum oxide coating.

[0042] The present invention prepares the anti-corrosion coating on the metal surface by brushing, spraying or micro-arc oxidation; when the corrosion-resistant coating is prepared by spraying, a transition layer is preferably provided before the corrosion-resistant coating is provided on the surface of the flow channel structure to reduce the risk of coating shedding and cracking due to the mismatch between the expansion coefficient of the corrosion-resistant coating and the substrate. The thickness of the transition layer is 20 to 35 μm; the transition layer is an aluminum-titanium (Al-Ti) transition layer.

[0043] The present invention also provides a method for preparing a corrosion-resistant liquid cooling plate, comprising the following steps:

[0044] Processing a flow channel structure, a water inlet and a water outlet on the plate to obtain a bottom plate;

[0045] A corrosion-resistant coating is prepared on the surface of the flow channel structure, the bottom plate and the cover plate that are in direct contact with the coolant, wherein the corrosion-resistant coating comprises one or more of nano-aluminum nitride powder, nano-diamond powder, titanium dioxide powder and modified organic silicon high temperature resistant resin;

[0046] The bottom plate and the cover plate are sealed and connected by a low-temperature brazing process to obtain a corrosion-resistant liquid cooling plate.

[0047] The process provided by the invention is simple and easy to industrialize.

[0048] The present invention processes the flow channel structure, the water inlet and the water outlet on the plate to obtain the bottom plate. The present invention preferably processes the flow channel structure, the water inlet and the water outlet on the plate by numerical control machine tool (CNC) processing.

[0049] The present invention prepares a corrosion-resistant coating on the surface of the flow channel structure, the bottom plate and the cover plate that are in direct contact with the coolant. The present invention preferably prepares the anti-corrosion coating on the metal surface by brushing, spraying or micro-arc oxidation. The processes such as brushing, spraying or micro-arc oxidation are highly controllable and efficient and are suitable for various complex flow channel structures. Before preparing the corrosion-resistant coating, the present invention preferably performs a grinding and roughening treatment on the surface to enhance the bonding ability of the corrosion-resistant coating with the substrate; the present invention preferably uses 200 mesh coarse sandpaper for grinding and roughening. After grinding and roughening, place it in an ultrasonic cleaner for cleaning to remove residual particles on the surface; the cleaning time is preferably 25 to 35 minutes.

[0050] The present invention adopts a specific type of material as the raw material of the corrosion-resistant coating, so that the cold plate has excellent corrosion resistance and a higher thermal conductivity.

[0051] The present invention adopts a low-temperature brazing process to seal and connect the bottom plate and the cover plate to obtain a corrosion-resistant liquid cooling plate. The brazing material used for brazing is selected from one or more of Sn-Zn-Ge, Sn-Pb-Ag and Pb-Bi-Ag; the above-mentioned types of brazing material. The present invention adopts the above-mentioned types of brazing material to enable brazing to be performed at a lower temperature, reduce the risk of coating shedding and cracking during high-temperature brazing, and increase the service life of the coating.

[0052] In the present invention, the welding surface is preferably polished before welding to clean surface defects such as burrs; after polishing, the welded part is placed in an ultrasonic cleaning machine for cleaning to remove residual particles on the surface; the cleaning time is 25 to 35 minutes.

[0053] The brazing temperature in the present invention is lower than 300° C. In a specific embodiment, the brazing temperature is 240° C. or 250° C. The brazing is carried out in a nitrogen atmosphere in the present invention. The brazing insulation time in the present invention is 50 to 70 minutes, preferably 55 to 65 minutes. In a specific embodiment, the brazing insulation time is 60 minutes.

[0054] Figure 2The schematic diagram of the preparation process of the corrosion-resistant liquid cooling plate of the present invention comprises the following steps: CNC machining a metal plate to obtain a plate with a water inlet and outlet and a flow channel structure, and then coating the plate to obtain an anti-corrosion treated metal plate; and adopting a low temperature brazing process to obtain a corrosion-resistant cooling plate.

[0055] In order to further illustrate the present invention, a corrosion-resistant liquid cooling plate and a preparation method thereof provided by the present invention are described in detail below in combination with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0056] Example 1

[0057] Step 1: Processing of cold plate runner, inlet and outlet

[0058] (1) Processing the internal flow channel structure 3 and the water inlet and outlet threaded ports 2 on the aluminum alloy plate by means of a numerical control machine tool (CNC) for later connection with a water pipe quick connector;

[0059] Step 2: Preparation of surface corrosion-resistant coating

[0060] (1) Apply high-temperature nano anti-corrosion coating to the flow channel structure and upper and lower plate parts that are in direct contact with the coolant. Before painting, the surface is roughened with 200-mesh coarse sandpaper to enhance the bonding ability between the coating and the substrate. After grinding, it is placed in an ultrasonic cleaning machine for 30 minutes to clean the residual particles on the surface;

[0061] (2) Then place the cold plate after painting in a drying oven at 80°C for 1 hour until the paint is completely cured;

[0062] (3) The main components of the high-temperature anti-corrosion coating are a composite powder of diamond powder and aluminum nitride powder with a particle size of 0.5 to 5 μm in a mass ratio of 10:20 and a polyimide-modified silicone high-temperature resistant resin, wherein the mass ratio of diamond to aluminum nitride in the composite powder is 2:1. The prepared coating has a thickness of 35 μm and a thermal conductivity of 20 W / (m·K), which has excellent corrosion resistance and a high thermal conductivity.

[0063] Step 3: Low temperature brazing

[0064] (1) The upper cover plate 4 and the anti-corrosion structure 1 obtained after the treatment in step 2 are connected by low-temperature brazing. Before welding, the welding surface is firstly polished with 400-mesh sandpaper to clean the surface burrs and other defects. After polishing, the welded parts are placed in an ultrasonic cleaning machine for cleaning for 30 minutes to clean the residual particles on the surface;

[0065] (2) The solder used is Sn-Zn eutectic solder, the welding temperature is 240°C, the welding atmosphere is nitrogen, and the holding time is 1 hour.

[0066] Example 2

[0067] Step 1: Processing of cold plate runner, inlet and outlet

[0068] (1) The internal flow channel structure 3 and the water inlet and outlet threaded ports 2 are processed on the aluminum alloy plate by CNC processing, which are used for subsequent connection with the water pipe quick connector.

[0069] Step 2: Preparation of surface corrosion resistant coating.

[0070] (1) The flow channel structure and the upper and lower plate parts that are in direct contact with the coolant are plasma sprayed with a corrosion-resistant ceramic coating. Before spraying, the surface is roughened with 200-grit sandpaper to enhance the adhesion of the surface coating. After grinding, it is placed in an ultrasonic cleaning machine for 30 minutes to clean the surface particles;

[0071] (2) In order to reduce the risk of coating shedding and cracking, a 30 μm aluminum-titanium (Al-Ti) transition layer is sprayed on the surface of the cold plate flow channel to reduce the risk of coating shedding and cracking caused by the mismatch between the thermal expansion coefficients of the coating and the substrate;

[0072] (3) Then, a corrosion-resistant ceramic coating is plasma sprayed on the surface of the Al-Ti transition layer, wherein the ceramic spray material is a composite powder of aluminum nitride powder and titanium dioxide powder in a mass ratio of 2:1. The spray coating thickness is 50 μm, and the thermal conductivity of the coating is 60 W / (m·K). It has excellent corrosion resistance and high thermal conductivity.

[0073] Step 3: Low temperature brazing

[0074] (1) The upper cover plate 4 and the anti-corrosion structure 1 obtained after the treatment in step 2 are connected by low-temperature brazing. Before welding, the welding surface is first polished with 600-mesh sandpaper. After polishing, the welded parts are placed in an ultrasonic cleaning machine for cleaning for 30 minutes to clean the residual particles on the surface;

[0075] (2) The solder used is Sn-Zn eutectic solder, the welding temperature is 250°C, the welding atmosphere is nitrogen, and the holding time is 1 h.

[0076] Example 3

[0077] Step 1: Processing of cold plate runner, inlet and outlet

[0078] (1) Processing the internal flow channel structure 3 and the water inlet and outlet threaded ports 2 on the aluminum alloy plate by CNC processing for later connection with the water pipe quick connector;

[0079] Step 2: Preparation of surface corrosion-resistant coating

[0080] (1) The flow channel structure and the upper and lower plate parts that are in direct contact with the coolant are subjected to an in-situ generation of an aluminum oxide corrosion-resistant coating with a thickness of 30 μm on the surface of the aluminum alloy by a micro-arc oxidation process, and the thermal conductivity of the coating is 25 W / (m·K); before the oxidation treatment, an epoxy resin layer is applied to the position that does not need to be oxidized for isolation treatment;

[0081] (2) Then the aluminum alloy substrate is used as the anode, the stainless steel is used as the cathode, the aluminate and potassium hydroxide are used as the electrolyte, the electrolysis temperature is 30°C, and the electrolysis time is 5 minutes. After the electrolysis is completed, the surface is rinsed with deionized water, and the surface epoxy resin sealing layer is polished with 800-grit sandpaper;

[0082] Step 3: Low temperature brazing.

[0083] (1) The upper cover plate 4 and the anti-corrosion structure 1 obtained after the treatment in step 2 are connected by low-temperature brazing. Before welding, the welding surface is first polished with 600-mesh sandpaper. After polishing, the welded parts are placed in an ultrasonic cleaning machine for cleaning for 30 minutes to clean the residual particles on the surface;

[0084] (2) The solder used is Sn-Zn eutectic solder, the welding temperature is 240°C, the welding atmosphere is nitrogen, and the holding time is 1 hour.

[0085] Comparative Example 1

[0086] The basic implementation process is the same as that of Example 1, except that unmodified organic silicone resin is added.

[0087] Comparative Example 2

[0088] The basic implementation process is the same as that of Example 2, except that no Al-Ti transition layer is sprayed on the surface.

[0089] The present invention performs a performance test on the cold plate prepared in the above embodiment and the comparative example: referring to the ISO12944-6 standard, a salt spray test chamber is used to verify the corrosion resistance test of the prepared coating, and the test is performed for 720 hours in a C3 environment. After the test is completed, the surface condition of the coating is observed. The results are shown in Table 1:

[0090] Table 1 Performance test results of cold plates prepared in Examples and Comparative Examples

[0091]

[0092] It can be seen from the above embodiments that the present invention provides a corrosion-resistant liquid cooling plate, comprising a bottom plate and a cover plate connected to each other; a flow channel structure is provided on the end surface of the bottom plate facing the cover plate; a corrosion-resistant coating is provided on the surface of the flow channel structure; the corrosion-resistant coating comprises one or more of nano-aluminum nitride powder, nano-diamond powder, titanium dioxide powder and modified silicone high-temperature resistant resin; one of the two opposite ends of the flow channel structure is a water inlet and the other is a water outlet. The corrosion-resistant liquid cooling plate provided by the present invention improves the corrosion resistance of the cold plate by providing a specific type of corrosion-resistant coating on the surface of the flow channel structure.

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A corrosion-resistant liquid cooling plate, characterized in that: including a base plate and a cover plate connected to each other; The end surface of the bottom plate facing the cover plate is provided with a flow channel structure; The surface of the flow channel structure is provided with a corrosion-resistant coating; The corrosion-resistant coating comprises one or more of nano-aluminum nitride powder, nano-diamond powder, titanium dioxide powder and modified organic silicon high temperature resistant resin; One of the two opposite ends of the flow channel structure is a water inlet, and the other is a water outlet.

2. The corrosion-resistant liquid cooling plate according to claim 1, characterized in that: The thickness of the corrosion-resistant coating is 30-50 μm.

3. The corrosion-resistant liquid cooling plate according to claim 1, characterized in that: The water inlet is a water inlet threaded port; The water outlet is a water outlet threaded port.

4. The corrosion-resistant liquid cooling plate according to claim 1, characterized in that: The flow channel structure is divided by spacers to form a circuitous flow channel.

5. The corrosion-resistant liquid cooling plate according to claim 1, characterized in that: The thermal conductivity of the corrosion-resistant coating is 20 to 60 W / (mk).

6. The corrosion-resistant liquid cooling plate according to claim 1, characterized in that: The bottom plate and / or cover plate are made of aluminum alloy plate.

7. The corrosion-resistant liquid cooling plate according to claim 1, characterized in that: The bottom plate and the cover plate are sealed and connected by solder; The solder is selected from one or more of Sn-Zn-Ge, Sn-Pb-Ag and Pb-Bi-Ag.

8. A method for preparing a corrosion-resistant liquid cooling plate, comprising the following steps: Processing a flow channel structure, a water inlet and a water outlet on the plate to obtain a bottom plate; A corrosion-resistant coating is prepared on the surface of the flow channel structure, the bottom plate and the cover plate that are in direct contact with the coolant, wherein the corrosion-resistant coating comprises one or more of nano-aluminum nitride powder, nano-diamond powder, titanium dioxide powder, carbon nanotubes and modified organic silicon high temperature resistant resin; The bottom plate and the cover plate are sealed and connected by a low-temperature brazing process to obtain a corrosion-resistant liquid cooling plate.

9. The preparation method according to claim 8, characterized in that: The corrosion-resistant coating is prepared by brushing, spraying or micro-arc oxidation.

10. The preparation method according to claim 8, characterized in that: The brazing material used for brazing is selected from one or more of Sn-Zn-Ge, Sn-Pb-Ag and Pb-Bi-Ag; The brazing temperature is below 300°C.

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