Front and back passivation process of water cooling plate

Abstract

The passivated water cooling plate comprises an upper cooling plate body, a lower cooling plate body and a connecting pipe, the upper cooling plate body and the lower cooling plate body are welded in a sealed mode, the connecting pipe is arranged on the upper cooling plate body, and the connecting pipe is communicated with the interior of the upper cooling plate body and the interior of the lower cooling plate body. The passivation process specifically comprises the steps of early-stage preparation, cleaning treatment, passivation treatment, post-treatment and final inspection. Before the water cooling plate is passivated, helium detection and gas detection need to be carried out on a product to ensure the sealing performance of the product, meanwhile, a connecting pipe is also sealed to prevent passivation liquid from flowing into the water cooling plate from the periphery of the water cooling plate, and an ultrasonic cleaning technology is used before passivation, so that fine pollutants on the surface can be more effectively removed; a cleaner and smoother surface is provided for the passivating agent, after passivating treatment, a layer of compact passive film is formed on the surface of the water cooling plate, and water, oxygen and other corrosive substances can be effectively prevented from making direct contact with a base material.

Description

Technical Field

[0001] The invention relates to the technical field of water cooling plate passivation, in particular to a front and back surface passivation process of a water cooling plate. Background Art

[0002] Water-cooled plates are usually made of metal, such as aluminum or copper. Aluminum water-cooled plates are more susceptible to corrosion in certain environments, and water-cooled plates are more susceptible to corrosion in high-temperature, high-humidity or polluted environments. Common anti-corrosion measures for water-cooled plates on the market include anodizing, electroplating, coating, etc., but these anti-corrosion measures will greatly increase the manufacturing cost. Passivation as a pre-coating step can not only achieve the effect of anti-corrosion, but also reduce the cost of the anti-corrosion process. Summary of the invention

[0003] The purpose of the present invention is to provide a passivation process for the front and back surfaces of a water-cooled plate. After the passivation treatment, a dense passivation film is formed on the surface of the water-cooled plate, which can effectively prevent moisture, oxygen and other corrosive substances from directly contacting the substrate, thereby preventing oxidation and corrosion. The passivation treatment helps to improve the surface cleanliness, making the surface smoother and less prone to adsorbing pollutants. The passivation treatment will not weaken the mechanical properties of the water-cooled plate, but on the contrary, by improving the surface quality, it enhances its overall reliability and solves the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solution: a front and back passivation process of a water-cooled plate, the water-cooled plate comprising an upper cold plate, a lower cold plate and a connecting pipe, the upper cold plate and the lower cold plate are sealed and welded, a connecting pipe is provided on the upper cold plate, and the connecting pipe is connected to the interior of the upper cold plate and the lower cold plate, and the passivation process specifically comprises the following steps:

[0005] Preliminary preparation: Before the passivation treatment, the water-cooling plate should be tested for air tightness and special parts of the water-cooling plate should be shielded;

[0006] Cleaning: Use ultrapure water to thoroughly clean the water-cooling plate at least twice to remove dust, oil or other foreign matter on the surface of the water-cooling plate;

[0007] Passivation treatment: prepare the passivation solution and spray it evenly on the front and back surfaces of the water-cooled plate. Keep the spraying time for 2 to 3 minutes.

[0008] Post-processing: After spraying, use ultrapure water to thoroughly clean the water-cooled plate again to remove the residual passivation solution and dry the water-cooled plate.

[0009] Final Inspection: After drying, all coverings are removed and the water-cooled plate is thoroughly inspected to ensure that all treatment processes meet standards and the surface is smooth and free of defects.

[0010] Preferably, the specific method of the preliminary preparation is as follows:

[0011] Use compressed air to blow on the surface of the cold plate to ensure that the surface of the water-cooled plate is clean and dust-free. Use a special sealing plug or sealing tape to close one of the connecting pipes of the water-cooled plate to prevent gas leakage. Reserve a connecting pipe for inflation. Use the air source to inflate the inside of the water-cooled plate through the reserved connecting pipe. The inflation pressure should be slightly higher than the atmospheric pressure, but not too high to prevent damage to the water-cooled plate. Check for gas leaks, record any leaks found during the inspection, and mark the locations. For detected leaks, they should be repaired immediately. Common repair methods include welding, applying sealant, etc. After repair, re-test for air tightness to ensure that all leaks have been effectively repaired to prevent the passivation solution from penetrating into the interior and causing adverse effects. After the air tightness meets the standard, use special sealing tape to mask the laser coding and connecting pipe parts on the upper cold plate, and ensure that the sealing strip is firm to prevent the passivation solution from penetrating.

[0012] Preferably, the air tightness test adopts helium detection or gas detection, and the inflation pressure is 1.3-1.6 atmospheres. If a helium detector is used, the detection head is close to various parts of the water-cooled plate, especially welding joints, connections and other places where leakage may exist for detection. Helium molecules are very small and can easily leak out through tiny gaps. The helium detector can sensitively detect the presence of helium. If a water tank is used for bubble detection, the water-cooled plate is immersed in water and carefully observed to see if there are bubbles. If there are bubbles, it indicates that there is a leak.

[0013] Preferably, the specific method of the cleaning treatment is as follows:

[0014] Initial cleaning: Use ultrapure water to perform preliminary cleaning on the water cooling plate to remove obvious dust and particles on the surface;

[0015] Degreasing: Soak the water-cooled plate in hot water containing alkaline detergent and use an ultrasonic cleaner to remove grease and hard-to-remove contaminants. Heating can increase the solubility of the solution and the chemical reaction rate, while ultrasonic cleaning removes contaminants by generating tiny bubbles. The combination of the two can more thoroughly remove dirt on the surface and in the gaps;

[0016] Rinse: Rinse the water cooling plate thoroughly with running ultrapure water to ensure that all cleaning agents and loose contaminants are washed away;

[0017] Drying: Dry naturally or use compressed air to ensure that the surface of the water cooling plate is completely dry to avoid rust or re-contamination;

[0018] Inspection: Check the water cooling plate after cleaning to ensure that the surface is clean and free of contamination. If necessary, repeat the above steps until the requirements are met.

[0019] Preferably, the specific method of the cleaning treatment is as follows:

[0020] Initial cleaning: Use ultrapure water to perform preliminary cleaning on the water cooling plate to remove obvious dust and particles on the surface;

[0021] Degreasing: Soak the water-cooled plate in hot water containing alkaline detergent and use an ultrasonic cleaner to remove grease and difficult-to-remove contaminants;

[0022] Rinsing: After cleaning, rinse the water cooling plate thoroughly with running ultrapure water to ensure that all cleaning agents and loose contaminants are washed away;

[0023] Pickling: If there is an oxide layer or other contaminants on the surface of the water-cooled plate that are difficult to remove by alkaline cleaning, pickling can be used to remove the oxide using diluted acid;

[0024] Neutralization: In order to prevent the acidic residue from having adverse effects on subsequent treatment, it is necessary to use an alkaline solution for neutralization;

[0025] Final rinse: Use running ultrapure water to rinse the water cooling plate again to ensure that there is no residue on the surface;

[0026] Drying: Dry naturally or use compressed air to ensure that the surface of the water cooling plate is completely dry to avoid rust or re-contamination;

[0027] Inspection: Check the water cooling plate after cleaning to ensure that the surface is clean and free of contamination. If necessary, repeat the above steps until the requirements are met.

[0028] Preferably, the hot water containing the alkaline cleaning agent is a 5%-10% sodium hydroxide solution heated to 60°C-80°C. Heating can improve the solubility of the solution, making sodium hydroxide more easily dissolved in water to form a uniform solution, speeding up the cleaning rate, enhancing the emulsification effect of oil stains, activating the surface of the water-cooled plate, making it easier to react with the cleaning agent, thereby improving the cleaning efficiency. The frequency of the ultrasonic cleaning machine is between 20kHz-40kHz, and the cleaning time is 10-20 minutes.

[0029] Preferably, the pickling solution is a 5% dilute sulfuric acid solution, in which the degreased water-cooled plate is immersed for 5 minutes.

[0030] Preferably, the alkaline solution used for neutralization is a 2% sodium carbonate solution, and the neutralization time is immersing the water-cooled plate for 2 minutes.

[0031] Preferably, the passivation solution is prepared by mixing the passivation agent BONDERITE M-NT 5200MU MSDS with ultrapure water in a ratio of 0.15% to 0.45%.

[0032] Preferably, during the drying, the cleaned water-cooled plate is placed in a drying chamber with a preset temperature of 150° C. to 155° C., and the drying is continued for more than 20 minutes.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] In summary: the present invention proposes a front and back passivation process for a water-cooled plate. Before passivation, the water-cooled plate needs to be subjected to helium inspection and gas inspection to ensure the sealing of the product. At the same time, the connecting pipe is also sealed to prevent the passivation solution from flowing into the water-cooled plate from the surrounding of the cold plate. Before passivation, the water-cooled plate is cleaned in multiple passes and ultrasonic cleaning technology is used to more effectively remove fine contaminants on the surface and provide a cleaner and smoother surface for the passivator. After passivation, a dense passivation film is formed on the surface of the water-cooled plate, which can effectively prevent moisture, oxygen and other corrosive substances from directly contacting the substrate, thereby preventing oxidation and corrosion. The passivation treatment helps to improve the surface cleanliness, making the surface smoother and less prone to adsorbing contaminants. The passivation treatment will not weaken the mechanical properties of the water-cooled plate, but on the contrary, enhance its overall reliability by improving the surface quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is an exploded view of the water cooling plate of the present invention.

[0036] In the figure: 1. upper cold plate; 2. lower cold plate; 3. connecting pipe. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Embodiment 1:

[0039] In order to solve the problem that common anti-corrosion measures for water cooling plates in the existing market include anodizing, electroplating, coating, etc., but these anti-corrosion measures will greatly increase the manufacturing cost. Passivation as a pre-coating step can not only achieve the anti-corrosion effect, but also reduce the cost of the anti-corrosion process. Please refer to Figure 1 , this embodiment provides the following technical solutions:

[0040] A front and back passivation process of a water-cooled plate, the water-cooled plate comprises an upper cold plate 1, a lower cold plate 2 and a connecting pipe 3, the upper cold plate 1 and the lower cold plate 2 are sealed and welded, the upper cold plate 1 is provided with a connecting pipe 3, the connecting pipe 3 is connected with the interior of the upper cold plate 1 and the lower cold plate 2, the passivation process specifically comprises the following steps:

[0041] Before conducting helium inspection or gas inspection, first ensure that the surface of the water-cooled plate is clean and dust-free. You can use compressed air or a soft cloth to wipe the surface of the water-cooled plate. Prepare the helium detector or gas inspection equipment and ensure that the equipment is in good working condition. Use a special sealing plug or sealing tape to seal one of the connecting pipes 3 of the water-cooled plate to prevent gas leakage. Keep the other connecting pipe 3 connected to the inside of the water-cooled pipe and inflate the connecting pipe 3. Use a compressed air source to inflate the inside of the water-cooled plate through the reserved interface. The inflation pressure is set to 1.5 atmospheres. Use the detection head of the helium detector to move along the surface of the water-cooled plate, especially carefully check the welds and joints. If helium leakage is detected, record the location of the leakage point, use welding equipment to weld and repair the detected leakage point, and use the helium detector again after repair to ensure that all leakage points have been repaired. Seal the connecting pipe 3 reserved for inflation, and use special sealing tape to cover the laser coding and connecting pipe 3 parts on the upper cold plate 1, and ensure that the sealing strip is firm to prevent the passivation solution from penetrating.

[0042] Use ultrapure water to clean the water-cooled plate by soaking to remove surface dust. Prepare a 5% sodium hydroxide solution, heat it to 80°C, and soak the water-cooled plate in the solution for 15 minutes. The ultrasonic frequency is 20kHz. Add a small amount of non-ionic surfactant to the solution to help emulsify the oil. Rinse the water-cooled plate thoroughly with ultrapure water to ensure that there is no alkaline residue, and blow it dry with compressed air.

[0043] Prepare the passivation solution, prepare a clean container large enough to hold the total amount of solution required, add 2000kg of ultrapure water into the container, slowly add the passivator to the water, add 3kg of Henkel passivator BONDERITEM-NT 5200MU, use a stirrer to fully mix the passivator and ultrapure water until the solution is uniform, fix the water-cooled plate to be treated in a position convenient for spraying, and ensure that both sides can be evenly sprayed, adjust the pressure of the sprayer before starting to spray, ensure that the solution can be evenly covered on the surface of the water-cooled plate, and evenly spray the passivation solution on both sides of the water-cooled plate. The spraying time is 3 minutes, during which the solution must be sprayed continuously to ensure that no part is missed.

[0044] After spraying, use ultrapure water to thoroughly clean the water-cooled plate again to remove the residual passivation solution. Place the cleaned water-cooled plate in a drying room with a preset temperature of 150℃ to 155℃ and continue drying for 20 minutes to ensure that the water-cooled plate is completely dry.

[0045] After drying is complete, all coverings are removed and the water-cooled plate is thoroughly inspected to ensure that all treatments have been carried out to standard and that the surface is smooth and free of defects.

[0046] Embodiment 2:

[0047] A front and back passivation process of a water cooling plate specifically comprises the following steps:

[0048] Before conducting helium inspection or gas inspection, first ensure that the surface of the water-cooled plate is clean and dust-free. You can use compressed air or a soft cloth to wipe the surface of the water-cooled plate. Prepare the helium detector or gas inspection equipment and ensure that the equipment is in good working condition. Use a special sealing plug or sealing tape to close one of the connecting pipes 3 of the water-cooled plate to prevent gas leakage. Keep the other connecting pipe 3 connected to the inside of the water-cooled pipe and inflate the connecting pipe 3. Use a compressed air source to inflate the inside of the water-cooled plate through the reserved interface. The inflation pressure is set to 1.4 atmospheres. Use a water tank to perform bubble detection, immerse the water-cooled plate in water, and carefully observe whether there are bubbles. If there are bubbles, it means that there is a leak point. Record the location of the leak point, use welding equipment to weld and repair the detected leak point, and perform gas inspection again after repair to ensure that all leak points have been repaired. Seal the connecting pipe 3 reserved for inflation, and use special sealing tape to cover the laser coding and connecting pipe 3 parts on the upper cold plate 1, and ensure that the sealing strip is firm to prevent the passivation solution from penetrating.

[0049] Use ultrapure water to clean the water-cooled plate by soaking to remove surface dust, prepare 10% sodium hydroxide solution, heat it to 60°C, soak the water-cooled plate in the solution for 10 minutes, the ultrasonic frequency is 30kHz, add a small amount of non-ionic surfactant to the solution to help emulsify the oil, rinse the water-cooled plate with ultrapure water to ensure that there is no alkaline residue, prepare a 5% dilute sulfuric acid solution, and soak the degreased water-cooled plate in it for 5 minutes. This step is used to remove the oxide layer and other difficult-to-remove contaminants on the surface of the water-cooled plate. Use 2% sodium carbonate solution to soak the water-cooled plate for 2 minutes to neutralize the acidic substances remaining on the surface, rinse the water-cooled plate with ultrapure water, and blow it dry with compressed air.

[0050] Prepare the passivation solution, prepare a clean container large enough to hold the total amount of solution required, add 2000kg of ultrapure water into the container, slowly add the passivator to the water, add 6kg of Henkel passivator BONDERITEM-NT 5200MU, use a stirrer to fully mix the passivator and ultrapure water until the solution is uniform, fix the water-cooled plate to be treated in a position convenient for spraying, and ensure that both sides can be evenly sprayed, adjust the pressure of the sprayer before starting to spray, ensure that the solution can be evenly covered on the surface of the water-cooled plate, and evenly spray the passivation solution on both sides of the water-cooled plate for 2 minutes. During this period, keep spraying the solution continuously to ensure that no part is missed.

[0051] After spraying, use ultrapure water to thoroughly clean the water-cooled plate again to remove the residual passivation solution. Place the cleaned water-cooled plate in a drying room with a preset temperature of 150℃ to 155℃ and continue drying for 20 minutes to ensure that the water-cooled plate is completely dry.

[0052] After drying is complete, all coverings are removed and the water-cooled plate is thoroughly inspected to ensure that all treatments have been carried out to standard and that the surface is smooth and free of defects.

[0053] In this embodiment, pickling and neutralization steps are added, which is suitable for water-cooled plates with heavy oil stains, oxide layers or other stubborn pollutants on the surface.

[0054] The water-cooled plates after passivation in Example 1 and Example 2 were subjected to a salt spray test, and the water-cooled plates without passivation were subjected to a control test. The test conditions were set according to the operating manual of the salt spray corrosion test chamber, usually at a temperature of 35°C ± 2°C and a relative humidity of more than 85%. A salt solution was prepared to ensure that the concentration was 5% NaCl. The samples were placed in the salt spray corrosion test chamber to ensure that the samples did not contact each other, and the following data were obtained:

[0055]

[0056] It can be concluded from the above table that the water-cooled plate that has been passivated has strong corrosion resistance and can ensure the normal operation of the water-cooled plate under special conditions.

[0057] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0058] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. A front and back passivation process for a water-cooled plate, the passivated water-cooled plate comprising an upper cold plate (1), a lower cold plate (2) and a connecting pipe (3), the upper cold plate (1) and the lower cold plate (2) being sealed and welded, the upper cold plate (1) being provided with a connecting pipe (3), the connecting pipe (3) being connected to the interior of the upper cold plate (1) and the lower cold plate (2), characterized in that: The passivation process specifically includes the following steps: Preliminary preparation: Before the passivation treatment, the water-cooling plate should be tested for air tightness and special parts of the water-cooling plate should be shielded; Cleaning: Use ultrapure water to thoroughly clean the water-cooling plate at least twice to remove dust, oil or foreign matter on the surface of the water-cooling plate; Passivation treatment: prepare the passivation solution and spray it evenly on the front and back surfaces of the water-cooled plate. Keep the spraying time for 2 to 3 minutes. Post-processing: After spraying, use ultrapure water to thoroughly clean the water-cooled plate again to remove the residual passivation solution and dry the water-cooled plate; Final Inspection: After drying is complete, remove all coverings and inspect the water-cooled plate.

2. The front and back surface passivation process of the water-cooling plate according to claim 1, characterized in that: The specific methods of the preliminary preparation are as follows: Use compressed air to blow the surface of the cold plate, use a special sealing plug or sealing tape to seal one of the connecting pipes (3) of the water-cooled plate, reserve one connecting pipe (3) for inflation, use an air source to inflate the inside of the water-cooled plate through the reserved connecting pipe (3), detect whether there is gas leakage, record the leakage points found during the detection process, and mark the positions, repair the detected leakage points, re-test the air tightness after the repair, and after the air tightness meets the standard, use special sealing tape to cover the laser coding and connecting pipe (3) parts on the upper cold plate (1).

3. The front and back surface passivation process of the water-cooling plate according to claim 2, characterized in that: The air tightness test adopts helium test or gas test, and the inflation pressure is 1.3-1.6 atmospheres.

4. The front and back surface passivation process of the water-cooling plate according to claim 1, characterized in that: The specific method of the cleaning treatment is as follows: Initial cleaning: Use ultrapure water to perform preliminary cleaning on the water cooling plate to remove obvious dust and particles on the surface; Degreasing: Soak the water-cooled plate in hot water containing alkaline detergent and use an ultrasonic cleaner to remove grease and difficult-to-remove contaminants; Rinse: Rinse the water-cooled plate with running ultrapure water to wash away the cleaning agent and loose contaminants; Drying: Dry naturally or use compressed air to dry; Inspection: Inspect the water-cooled plate after cleaning.

5. The front and back surface passivation process of the water-cooling plate according to claim 1, characterized in that: The specific method of the cleaning treatment is as follows: Initial cleaning: Use ultrapure water to perform preliminary cleaning on the water cooling plate to remove dust and particles on the surface; Degreasing: Soak the water-cooled plate in hot water containing alkaline detergent and use an ultrasonic cleaner to remove grease and contaminants; Rinsing: After cleaning, rinse the water cooling plate with running ultrapure water to wash away the cleaning agent and contaminants; Pickling: Use dilute acid to remove oxides; Neutralization: Use alkaline solution for neutralization; Final rinse: Rinse the cooling plate again with flowing ultrapure water; Drying: Dry naturally or use compressed air to dry; Inspection: Inspect the water-cooled plate after cleaning.

6. The front and back surface passivation process of the water-cooling plate according to claim 4 or 5, characterized in that: The hot water containing alkaline cleaning agent is 5%-10% sodium hydroxide solution heated to 60℃-80℃, the frequency of the ultrasonic cleaning machine is between 20kHz-40kHz, and the cleaning time is 10-20 minutes.

7. The front and back surface passivation process of the water-cooling plate according to claim 5, characterized in that: The pickling solution is a 5% dilute sulfuric acid solution, and the degreased water-cooled plate is immersed in it for 5 minutes.

8. The front and back surface passivation process of the water-cooling plate according to claim 5, characterized in that: The alkaline solution used for neutralization is a 2% sodium carbonate solution, and the neutralization time is immersing the water-cooled plate for 2 minutes.

9. The front and back surface passivation process of the water-cooling plate according to claim 1, characterized in that: The passivation solution is prepared by mixing the passivation agent BONDERITE M-NT 5200MU MSDS with ultrapure water in a ratio of 0.15% to 0.45%.

10. The front and back surface passivation process of the water-cooling plate according to claim 1, characterized in that: During the drying process, the cleaned water-cooled plate is placed in a drying chamber with a preset temperature of 150° C. to 155° C. and dried for more than 20 minutes.

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