Microchannel cold plate and method for manufacturing the same

Abstract

The present invention discloses a microchannel cold plate and a manufacturing method thereof, and relates to the technical field of workpiece processing. The microchannel cold plate comprises a flow channel plate A, a flow channel plate B, and a flow channel cavity located between the flow channel plate A and the flow channel plate B. The flow channel cavity is provided with a fluid inlet at one end and a fluid outlet at the other end. The flow channel plate A and the flow channel plate B are fixed by double-sided laser welding. The present application adopts double-sided laser welding to weld and fix the flow channel plate A and the flow channel plate B. The double-sided laser welding method is conducive to offsetting the thermal deformation and stress caused by the rapid cooling of the welding zone and the related material shrinkage, and is conducive to ensuring the flatness of the microchannel cold plate.

Description

Technical Field

[0001] The invention relates to the technical field of workpiece processing, and in particular to a microchannel cold plate and a manufacturing method thereof. Background Art

[0002] The microchannel cold plate has a small thickness and a compact structure, and the operating space is limited. The traditional tungsten inert gas arc welding method and welding process are easy to affect the microchannel around the weld, which may cause blockage or melt spatter entering the cavity, etc., and the welding quality cannot be ensured. If brazing is used for welding, the brazing material is easy to flow and has poor corrosion resistance. The air tightness of the cold plate after brazing is not ideal, and slight leakage often occurs, which affects the overall heat dissipation efficiency of the heat dissipation module and the stability of the equipment. In addition, the heat affected zone of brazing is large, which causes a certain degree of deformation of the cold plate, and indirectly affects the heat dissipation effect. If diffusion welding is used for welding, the material processing requirements are high, the structural applicability is poor, and the cost is high and the cycle is long.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] The object of the present invention is to provide a microchannel cold plate and a manufacturing method thereof, so as to overcome the problem that the welded microchannel cold plate in the prior art is easy to deform.

[0005] The present invention is achieved in that:

[0006] In a first aspect, the present invention provides a microchannel cold plate, comprising a flow channel plate A, a flow channel plate B, and a flow channel cavity located between the flow channel plate A and the flow channel plate B, wherein a fluid inlet is provided at one end of the flow channel cavity, and a fluid outlet is provided at the other end, and the flow channel plate A and the flow channel plate B are welded by double-sided laser welding.

[0007] In an optional embodiment, the cross section of the flow channel cavity along the direction perpendicular to the fluid flow direction is a rounded n-gon, where n is a positive integer ≥ 3;

[0008] And / or, a cross section of the flow channel cavity along the fluid flow direction is a rounded n-gon, where n is a positive integer ≥3.

[0009] In an optional embodiment, the thickness of the microchannel cold plate is 0.2 to 5 mm, and the flatness of the microchannel cold plate is less than 0.1 mm;

[0010] And / or, the material of the microchannel cold plate is at least one of stainless steel, titanium alloy, copper alloy and aluminum alloy.

[0011] In a second aspect, the present invention provides a method for manufacturing a microchannel cold plate according to any one of the aforementioned embodiments, comprising:

[0012] Assembling, cleaning the surfaces of the flow channel plate A and the flow channel plate B and then assembling them to obtain a combined welded part;

[0013] Vacuuming, connecting the flow channel cavity of the combined welded parts to a vacuuming system to keep the flow channel cavity in a negative pressure state;

[0014] Laser welding is used to irradiate the preset welding path on the flow channel plate A with laser to form a weld A on the flow channel plate A; laser welding is used to irradiate the preset welding path on the flow channel plate B with laser to form a weld B on the flow channel plate B; and a microchannel cold plate is obtained.

[0015] In an optional embodiment, the vacuum system includes a vacuum pump and a connecting pipe connected to the fluid inlet and / or the fluid outlet of the flow channel cavity;

[0016] And / or, the air pressure in the flow channel cavity is less than 10 -2 Laser welding is then performed after Pa;

[0017] And / or, the laser welding is performed under inert gas protection conditions.

[0018] In an optional embodiment, the vacuum system includes a vacuum pump and a suction cup for adsorbing and fixing the combined welded parts, the vacuum pump and the suction cup are connected by a connecting pipe, and the suction cup is adsorbed on the fluid inlet and / or fluid outlet of the flow channel cavity.

[0019] In an optional embodiment, the weld A and the weld B are both arranged along two sides of the flow channel cavity.

[0020] In an optional embodiment, the molten pool depth corresponding to weld A is D1+aD2; and / or, the molten pool depth corresponding to weld B is D2+bD1; wherein D1 is the thickness of runner plate A, D2 is the thickness of runner plate B, 1 / 2≤a≤2 / 3, 1 / 2≤b≤2 / 3.

[0021] In an optional embodiment, the laser power used for the laser welding is 500-1500 W, the welding speed is 5-30 mm / s, and the spot size is 0.2-0.5 mm.

[0022] In an optional embodiment, the welding gap of the combined parts to be welded is less than 0.15 mm.

[0023] The present invention has the following beneficial effects:

[0024] The present application adopts double-sided laser welding to weld the fixed flow channel plate A and the flow channel plate B. The double-sided laser welding method is beneficial to offset the thermal deformation and stress caused by the rapid cooling of the welding area and the related material shrinkage, and is beneficial to ensure the flatness of the microchannel cold plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 is a cross-sectional view of a microchannel cold plate;

[0027] Figure 2 This is the comparison of the flow channel cavity before and after welding;

[0028] Figure 3 Schematic diagram of the flow channel cavity, weld A and weld B in the microchannel cold plate in Example 1.

[0029] Illustration: 100- flow plate A; 110- weld A; 200- flow plate B; 210- weld B; 300- flow cavity. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0031] An embodiment of the present invention provides a microchannel cold plate, including a flow channel plate A100, a flow channel plate B200 and a flow channel cavity 300 located between the flow channel plate A100 and the flow channel plate B200, wherein the flow channel cavity 300 is provided with a fluid inlet at one end and a fluid outlet at the other end, and the flow channel plate A100 and the flow channel plate B200 are welded by double-sided laser welding.

[0032] The thickness of the microchannel cold plate is small, and the traditional direct contact welding method has problems such as easy welding through and large deformation. Laser welding is an efficient and precise welding method that uses a finely focused high-energy laser beam as a heat source for welding. It has the characteristics of high energy density, non-contact with the workpiece, high welding efficiency and easy automation. The weld has a large depth-to-width ratio, a narrow heat-affected zone, and small welding deformation. The weld is precise and firm, without defects such as pores, slag inclusions, and thermal cracks. It has good airtightness and can meet the high airtightness requirements of microchannel cold plates. At the same time, it can achieve micron-level weld size and position control, accurately weld microchannels and other small and complex structures, ensure the size accuracy and position accuracy of the microchannel, and ensure the heat dissipation performance of the cold plate. The laser beam has a fast heating speed and a short welding time. It can achieve efficient and fully automatic welding with an automated system, which is suitable for mass production and improves production efficiency. It also does not need to directly avoid contamination, deformation and damage caused by contact, which provides greater flexibility for welding microchannel cold plates of complex shapes, and will not have adverse effects on their internal structure and performance, which is conducive to obtaining microchannel cold plates with high weld quality, high precision, high efficiency and small thermal deformation.

[0033] Furthermore, in the embodiment of the present application, double-sided laser welding is used to weld and fix the flow channel plate A100 and the flow channel plate B200. The double-sided laser welding method is beneficial to offset the thermal deformation and stress caused by the rapid cooling of the welding area and the related material shrinkage, and is beneficial to ensure the flatness of the microchannel cold plate. Specifically, single-sided laser welding is only performed from one side. During the welding process, since the heat input is concentrated on one side, a large thermal stress will be generated. This thermal stress can easily cause the thin cold plate to deform toward the welding side, resulting in a decrease in flatness, and may cause bending, warping, etc. Double-sided laser welding is performed from both sides simultaneously or successively. The heat input is relatively evenly distributed on both sides of the plate, and the thermal stresses can offset each other to a certain extent, and the cold plate is hardly deformed.

[0034] In an optional embodiment, the cross section of the flow channel cavity 300 along the direction perpendicular to the fluid flow direction is a rounded n-gon, where n is a positive integer ≥ 3;

[0035] And / or, the cross section of the flow channel cavity 300 along the fluid flow direction is a rounded n-gon, where n is a positive integer ≥ 3, and the rounded corners are beneficial to reducing flow resistance.

[0036] In an optional embodiment, the thickness of the microchannel cold plate is 0.2 to 5 mm, and the flatness of the microchannel cold plate is less than 0.1 mm;

[0037] And / or, the microchannel cold plate is made of one of stainless steel, titanium alloy, copper alloy and aluminum alloy.

[0038] The microchannel cold plate in this application can maintain a flatness of less than 0.1mm at a thickness of 0.2 to 5mm. Flatness is affected by many factors, such as the material and thickness of the cold plate. For example, cold plates with a thickness of 0.5mm and 5mm have different degrees of deformation under the same welding conditions. Under the same conditions, the thinner the cold plate, the easier it is to deform. Microchannel cold plates with smaller flatness can better fit other components during installation and operation to ensure heat dissipation efficiency and overall performance.

[0039] The present invention also provides a method for manufacturing the microchannel cold plate according to any one of the above embodiments, such as Figure 1 and Figure 2 As shown, including:

[0040] Assembling, cleaning the surfaces of the flow channel plate A and the flow channel plate B and then assembling them to obtain a combined welded part;

[0041] Vacuuming, connecting the flow channel cavity 300 of the combined welded parts to a vacuuming system to keep the flow channel cavity 300 in a negative pressure state;

[0042] Laser welding is performed by irradiating a preset welding path on the flow channel plate A100 with laser light to form a weld A110 on the flow channel plate A100; laser welding is performed by irradiating a preset welding path on the flow channel plate B200 with laser light to form a weld B210 on the flow channel plate B200; and a microchannel cold plate is obtained.

[0043] In the embodiment of the present application, double-sided laser welding is used to weld and fix the flow channel plate A100 and the flow channel plate B200. The double-sided laser welding method is conducive to offsetting the thermal deformation and stress caused by the rapid cooling of the welding area and the related material shrinkage, and is conducive to ensuring the flatness of the microchannel cold plate. Furthermore, during laser welding, since the flow channel cavity 300 is in a negative pressure state, the right angle of the flow channel becomes a rounded corner, and the formation of the rounded corner is conducive to reducing the flow resistance. At the same time, the flow channel cavity 300 in a negative pressure state can play a buffering role, further suppressing the deformation and uneven stress distribution of the microchannel plate, so that the microchannel cold plate can maintain a flatness of less than 0.1mm at a thickness of 0.2 to 5mm.

[0044] In an optional embodiment, the vacuum system includes a vacuum pump and a connecting pipe connected to the fluid inlet and / or fluid outlet of the flow channel cavity 300;

[0045] And / or, the air pressure in the flow channel cavity 300 is less than 10 -2 Laser welding is then performed after Pa;

[0046] And / or, the laser welding is performed under inert gas protection conditions.

[0047] The vacuum degree in the flow channel cavity 300 is maintained at a relatively high level, and the fillet radius of the flow channel cavity 300 is larger, which is more conducive to reducing flow resistance.

[0048] It should be noted that there is still a gap between the manifold plate A100 and the manifold plate B200 in the combined welded parts. During the normal welding process, if the gas between the manifold plate A100 and the manifold plate B200 cannot be discharged in time, it may be retained in the microchannel cold plate, thereby affecting the performance of the microchannel cold plate. In the embodiment of the present application, while maintaining the vacuum in the manifold cavity 300, it can also promote the timely discharge of the gas between the manifold plate A100 and the manifold plate B200, thereby reducing the pores in the microchannel cold plate.

[0049] In an optional embodiment, the vacuum system includes a vacuum pump and a suction cup for adsorbing and fixing the combined welded parts. The vacuum pump and the suction cup are connected by a connecting pipe, and the suction cup is adsorbed at the fluid inlet and / or fluid outlet of the flow channel cavity 300.

[0050] The suction cup can provide vacuum conditions for the flow channel cavity 300 on the one hand, and can fix the combined welded parts without other clamps or fixing fixtures on the other hand.

[0051] It should be noted that the suction cup can cover both the fluid inlet and the fluid outlet of the flow channel cavity 300. If the suction cup is only sucked on one opening of the flow channel cavity 300, the other opening needs to be blocked to ensure the vacuum state in the flow channel cavity 300. One or more suction cups can be provided as needed, and the suction cups can be made of high temperature resistant materials with certain elasticity as needed.

[0052] In an optional embodiment, the weld A110 and the weld B210 are both arranged along two sides of the flow channel cavity 300 .

[0053] The welds A110 and B210 fix the flow channel plates A100 and B200 on one hand, and separate the various parts of the flow channel cavity 300 on the other hand, thereby ensuring that the fluid moves along a preset path in the flow channel cavity 300 .

[0054] It should be noted that the specific configuration of the flow channel cavity 300 can be as follows: Figure 3 As shown, the shapes of the weld A110 and the weld B210 can also be adjusted adaptively as required for flow channel cavities 300 of different shapes.

[0055] In an optional embodiment, the molten pool depth corresponding to weld A110 is D1+aD2; and / or, the molten pool depth corresponding to weld B210 is D2+bD1; wherein D1 is the thickness of runner plate A100, D2 is the thickness of runner plate B200, 1 / 2≤a≤2 / 3, 1 / 2≤b≤2 / 3.

[0056] If the molten pool depth is too large, the runner plate may be welded through. If the molten pool depth is too small, the welding strength of runner plate A100 and runner plate B200 will be too low. Therefore, the molten pool depth needs to be set reasonably.

[0057] In an optional embodiment, the laser power used for the laser welding is 500-1500 W, the welding speed is 5-30 mm / s, and the spot size is 0.2-0.5 mm.

[0058] Appropriate power is helpful to ensure that the weld material is fully melted to form a good weld; set an appropriate welding speed based on the laser power and the structural characteristics of the weld. If the speed is too fast, defects such as incomplete melting may occur, while if the speed is too slow, problems such as overheating and excessive deformation of the weld may occur. Select an appropriate spot diameter and control the energy distribution of the laser beam on the weld surface by adjusting the defocus amount to ensure that the weld penetration depth and width meet the welding quality requirements.

[0059] At the same time, the molten pool is required to have a regular and stable shape. A regular shape helps to ensure the beauty of the weld and avoid defects such as undercuts and humps. A stable molten pool can make the welding process go smoothly, which requires reasonable control of parameters such as laser power and welding speed.

[0060] In an optional embodiment, the welding gap of the combined parts to be welded is less than 0.15 mm.

[0061] In some embodiments, a method for manufacturing a microchannel cold plate comprises:

[0062] 1) Welding preparation: Determine the main substrate of the microchannel cold plate, and strictly inspect its material and size to ensure that the material quality is qualified, there are no obvious defects, and the thickness of the plate is uniform. Process the material according to the design requirements, and it may be necessary to form the flow channel plate structure through CNC processing or chemical etching.

[0063] 2) Surface cleaning: Use appropriate chemical reagents or physical grinding methods to remove oil, oxide layer and impurities on the surface of the cold plate to keep the welding surface clean, which is conducive to good absorption of laser energy and formation of welds during subsequent welding. Grind the butt welding surface to improve its flatness and contact area.

[0064] 3) Welding assembly: Assemble the components according to the design requirements to obtain the combined component to be welded, place the combined component to be welded on the suction cup, and while positioning the combined component to be welded, extract the gas in the flow channel cavity 300 corresponding to the combined component to be welded to maintain the vacuum condition in the flow channel cavity 300. The use of the suction cup does not require the use of a dedicated fixture for positioning, and can also ensure that the components maintain the correct position and gap during the welding process. Ensure that the gap of the microchannel meets the welding requirements.

[0065] 4) Laser welding parameter setting: Set the laser power, welding speed, focus position and other parameters according to the material and thickness of the microchannel cold plate.

[0066] 5) Implementation of the welding process: Start the laser welding equipment, first briefly start the arc at the starting position of the weldment, accurately locate the welding starting point, and observe the melting condition at the arc starting point to ensure that the starting state is good. Weld along the weld according to the preset welding path of the flow channel plate A100. Let the laser beam move at a constant speed along the weld of the microchannel cold plate, monitor the welding status in real time during the welding process, and monitor the parameters such as the weld depth and weld width through sensors and other equipment. If there is a deviation, adjust it in time. After flipping, weld again at a constant speed according to the preset welding path of the flow channel plate B200. The schematic diagram of the weld depth and weld is as follows Figure 1 shown.

[0067] 6) Post-weld treatment: After welding, check the weld appearance to see if it is smooth and continuous, and whether there are defects such as pores, cracks, and undercuts, by visual inspection or with the help of tools such as a magnifying glass. Mark the parts with appearance problems. Clean up the spatter and other impurities left around the weld. If the weld appearance is uneven, grind it appropriately to make its surface smooth and meet the requirements of subsequent use or assembly.

[0068] 7) For welds with high product quality requirements, non-destructive testing methods such as X-ray flaw detection and ultrasonic flaw detection can also be used to further detect the internal quality of the weld to ensure that there are no internal defects in the weld that affect the performance of the microchannel cold plate, so that the welded product meets the quality requirements. If the quality does not meet the requirements, analyze the reasons, such as unreasonable welding parameters, inadequate pretreatment of the thin plate surface, etc., take targeted improvement measures, and re-perform the welding operation.

[0069] 8) Perform fluid containment test on the cold plate to ensure that there are no leaks in the microchannels and verify their performance.

[0070] 9) Surface treatment: Coating, anodizing or other surface treatments may be performed as required to improve corrosion resistance and wear resistance.

[0071] 10) Functional test: Comprehensively test the thermal conductivity and fluid flow of the cold plate to ensure that the design requirements are met. Record the production process to ensure the traceability of each step for subsequent quality control. If necessary, the laser welding parameters can be optimized according to the actual material and product characteristics to obtain the best welding effect.

[0072] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0073] Example 1

[0074] This embodiment provides a method for manufacturing a stainless steel microchannel cold plate, and the specific steps include:

[0075] Preparation of weldments: prepare the 316 stainless steel cold plate to be welded, and carefully check its specifications, thickness, size and other parameters to ensure that the surface of the plate is flat and free of obvious pits, scratches, scale and other defects. Ensure that it meets the welding requirements. Surface cleaning: Use a clean wiping cloth to dip in an appropriate amount of organic solvents such as acetone or alcohol, and carefully wipe the welded parts and surrounding areas of the stainless steel cold plate to thoroughly remove impurities such as oil and dust to ensure that the welding surface is clean. Equipment preparation and debugging: Select a clean, dry, relatively stable temperature and humidity and well-ventilated site to place the vacuum laser welding equipment to avoid the equipment from being affected by dust, moisture, extreme temperatures and corrosive gases, and to ensure the performance and service life of the equipment. Debug the vacuum system, install the microchannel cold plate and the matching vacuum pump, vacuum pipe, and vacuum chamber. This embodiment is provided with a suction cup for fixing the combined weldment to be welded. The suction cup is connected to the vacuum chamber. Turn on the vacuum pump for a vacuum test, adjust the vacuum rate, vacuum degree and other parameters, and ensure that the vacuum chamber can reach 10 -2

[0076] Pa or less, check whether its operating status is normal. Place the laser welding equipment in a stable, dry and well-ventilated workplace, connect the power supply, cooling system, etc., to ensure that the equipment can operate normally. Connect the argon gas cylinder to the gas delivery pipeline through a pressure reducer, gas flow meter, etc., ensure that the connection is firm and the seal is reliable, open the argon gas cylinder valve, adjust the pressure reducer to stabilize the output pressure at 0.3~0.6MPa, and control the gas flow at 5~15L / min, so that a stable and effective protective gas hood can be formed in the welding area during welding to prevent the weld metal from contacting with the air and oxidizing. Debug the protective gas delivery system and adjust the gas flow so that it can stably cover the welding area during welding and play a good protective role. At the same time, check whether the components such as the combined parts to be welded and the combined parts to be welded placement platform are installed firmly and cleanly. Laser welding parameter setting: For 316 stainless steel thin cold plates with a thickness of 0.2 mm, the laser power should be appropriately lowered to prevent burn-through, and the welding speed can be slightly faster to ensure good weld formation. Therefore, the laser power is set to about 1300 watts and the welding speed is set to 200 mm per minute, and the parameters of the laser welding equipment are repeatedly debugged. At the same time, finely adjust the spot diameter and defocus to ensure that the laser beam can achieve ideal energy distribution on the surface of the weldment and ensure that it acts accurately on the welding part. Assembly: Carefully place the cleaned stainless steel cold plate on the workbench of the laser welding equipment. The operation process should be gentle to prevent the thin plate from colliding and deforming. Then assemble the cold plate according to the design requirements of the drawing, accurately place the stainless steel cold plate to be welded, ensure that the welding joints are aligned, the gap is uniform and meets the welding process requirements, and the general welding gap is controlled in a small range of about 0.15mm to ensure that the flow channel plate will not be displaced during the welding process. The degree of fixation can be checked by gently pulling the edge of the flow channel plate. If it is loose, it needs to be adjusted in time. Parameter review: Before welding, check the various parameters set on the laser welding equipment again, as well as the settings such as the protective gas flow rate, to ensure that all parameters are accurate and avoid welding failure or quality problems due to parameter errors. After confirmation, prepare to start welding. Start welding: Turn on the laser emission system of the laser welding equipment, and open the protective gas delivery valve at the same time to stably deliver argon gas to the welding area to form a protective gas hood. The laser beam is used to irradiate the welding part of the stainless steel cold plate according to the welding path preset by the flow channel plate A100. The stainless steel material is rapidly melted, fused, and solidified under the action of the laser energy to form a weld. After flipping, the weld is welded again at a uniform speed according to the welding path preset by the flow channel plate B200. The penetration depth and the weld diagram are shown in the figure below. Figure 1 As shown, the schematic diagram of the flow channel cavity 300, the weld A110 and the weld B210 in the microchannel cold plate is as shown in Figure 3 As shown, it should be noted that Figure 3This is only a schematic diagram of this embodiment. In other embodiments, the shape of the flow channel cavity 300 can be set as needed. During the welding process, the welding condition can be monitored in real time with the help of a welding monitoring system such as an optical imaging system to check the weld formation and whether there are abnormal phenomena such as spatter. If a problem is found, the welding is suspended in time and the parameters are adjusted before continuing. Turn off the equipment and gas: After the welding is completed, first turn off the laser welding equipment and the protective gas delivery system in turn, and stop the argon supply. Then turn off the vacuum pump, and according to the operating procedures of the vacuum pump, slowly release the vacuum degree in the vacuum chamber so that the chamber gradually returns to the normal pressure state to avoid adverse effects on the equipment or the welded flow channel plate due to sudden changes in pressure. Finally, turn off the cooling system and other related auxiliary systems of the equipment to ensure that there is no abnormal sound, water leakage, leakage, etc. after each system is turned off, and the equipment is in a safe and stable shutdown state. Post-weld processing: Carefully remove the welded stainless steel cold plate, use a brush or other tools to gently clean the impurities such as welding slag remaining on the surface of the weldment to keep the appearance of the weldment neat. It can also be properly polished to make its surface smooth and meet the requirements of subsequent use or assembly. Visual inspection shows that the weld is smooth and continuous, without defects such as pores, undercuts, and cracks. The microchannel cold plate is further tested with airtightness testing equipment, and the results show that the airtightness fully meets high standards. In addition, the thermal deformation caused by laser welding is extremely small, and the overall flatness of the cold plate is controlled within 0.08mm. The heat dissipation performance has been greatly improved in both subsequent assembly and actual use.

[0077] This comparative example adopts single-sided laser welding, and the only difference compared with Example 1 is that in step 8, step 9 is performed after the flow channel plate A100 surface is welded, and no weld B210 is formed on the obtained microchannel cold plate, and the overall flatness of the obtained cold plate is 0.3 mm.

[0078] For microchannel cold plates, single-sided laser welding will lead to larger flatness deviation, while double-sided laser welding can better maintain the flatness of the microchannel cold plate, which helps the microchannel cold plate to better fit other components during installation and operation, ensuring heat dissipation efficiency and overall performance.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a microchannel cold plate, characterized in that: The microchannel cold plate comprises a flow channel plate A, a flow channel plate B and a flow channel cavity located between the flow channel plate A and the flow channel plate B, wherein a fluid inlet is provided at one end of the flow channel cavity and a fluid outlet is provided at the other end, and the flow channel plate A and the flow channel plate B are welded by double-sided laser welding; the cross section of the flow channel cavity perpendicular to the fluid flow direction is a rounded n-gon, wherein n is a positive integer ≥3; And / or, the cross section of the flow channel cavity along the fluid flow direction is a rounded n-gon, where n is a positive integer ≥ 3 The manufacturing method of the microchannel cold plate comprises: Assembling, cleaning the surfaces of the flow channel plate A and the flow channel plate B and then assembling them to obtain a combined welded part; Vacuuming, connecting the flow channel cavity of the combined welded parts to a vacuuming system to keep the flow channel cavity in a negative pressure state; Laser welding is used to irradiate the preset welding path on the flow channel plate A with laser, so as to form a weld A on the flow channel plate A; laser welding is used to irradiate the preset welding path on the flow channel plate B with laser, so as to form a weld B on the flow channel plate B; a microchannel cold plate is obtained, wherein during laser welding, since the flow channel cavity is in a negative pressure state, the right angle of the flow channel is changed into a rounded angle.

2. The method for manufacturing a microchannel cold plate according to claim 1, characterized in that: The thickness of the microchannel cold plate is 0.2 to 5 mm, and the flatness of the microchannel cold plate is less than 0.1 mm; And / or, the material of the microchannel cold plate is one of stainless steel, copper alloy, titanium alloy and aluminum alloy.

3. The method for manufacturing a microchannel cold plate according to claim 1, characterized in that: The vacuum system comprises a vacuum pump and a connecting pipe connected to the fluid inlet and / or the fluid outlet of the flow channel cavity; And / or, the air pressure in the flow channel cavity is less than 10 -2 Laser welding is then performed after Pa; And / or, the laser welding is performed under inert gas protection conditions.

4. The method for manufacturing a microchannel cold plate according to claim 1, characterized in that: The vacuum system includes a vacuum pump and a suction cup for adsorbing and fixing the combined workpiece to be welded. The vacuum pump and the suction cup are connected via a connecting pipe, and the suction cup is adsorbed on the fluid inlet and / or fluid outlet of the flow channel cavity.

5. The method for manufacturing a microchannel cold plate according to claim 1, characterized in that: The weld A and weld B are both arranged along two sides of the flow channel cavity.

6. The method for manufacturing a microchannel cold plate according to claim 1, characterized in that: The molten pool depth corresponding to weld A is D1+aD2; and / or, the molten pool depth corresponding to weld B is D2+bD1; Wherein, D1 is the thickness of the flow channel plate A, D2 is the thickness of the flow channel plate B, 1 / 2≤a≤2 / 3, 1 / 2≤b≤2 / 3.

7. The method for manufacturing a microchannel cold plate according to claim 1, characterized in that: The laser power used for the laser welding is 500-1500W, the welding speed is 5-30mm / s, and the spot size is 0.2-0.5mm.

8. The method for manufacturing a microchannel cold plate according to claim 1, characterized in that: The welding gap of the combined parts to be welded is less than 0.15 mm.

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