A 3D printed water cooling plate and its manufacturing process

Abstract

The present invention specifically relates to a 3D printed water-cooled plate, including a flow channel portion and a cover portion; a flow channel cavity is provided in the flow channel portion, and the flow channel cavity includes an inlet flow channel, a first connecting flow channel, a first bending flow channel, a second bending flow channel, a second connecting flow channel, a third bending flow channel, a third connecting flow channel, a transition flow channel, a fourth bending flow channel, a fourth connecting flow channel, and an outlet flow channel arranged in sequence along the flow direction of the refrigerant; the inlet flow channel is connected to the refrigerant inlet provided on the cover portion, and the outlet flow channel is connected to the refrigerant outlet provided on the cover portion. The present invention maximizes the contact area between the refrigerant and the inner wall of the flow channel by changing the traditional uniform cross-section flow channel design to a uniform wall thickness and non-uniform flow channel cross-section design, and at the same time adding a circular arc transition section; the present invention adopts a layout form of local multi-flow channel parallel connection to reduce the flow resistance of the cold plate; the present invention optimizes the flow channel connection nodes to make the overall heat dissipation of the cold plate uniform and avoid excessive local temperature rise.

Description

Technical Field

[0001] The present invention belongs to the technical field of water cooling plates, and in particular relates to a 3D printed water cooling plate and a manufacturing process thereof. Background Art

[0002] With the development of electronic technology, the size of electronic equipment is getting smaller and smaller, the assembly density is getting higher and higher, and the overall dissipated power is increasing sharply, causing the heat dissipation problem of high heat flow in electronic equipment to become increasingly prominent. If the electronic equipment does not have good heat dissipation performance, it will have a significant impact on the performance and life of the entire equipment. At present, cold plates are mostly used to dissipate heat for high-density electronic equipment.

[0003] Most of the cold plates in the prior art are assembled together by welding various parts, the process is complicated, and the assembled products are prone to gaps; and the flow channels of the cold plates in the prior art mostly adopt a straight channel design, the heat exchange area between the refrigerant and the cold plate is small, the flow resistance of the cold plate is large, and the overall heat dissipation uniformity of the cold plate is poor, and the local temperature rise is prone to be too high. Summary of the invention

[0004] In view of the above-mentioned shortcomings, an object of the present invention is to provide a 3D printed water cooling plate and a manufacturing process thereof.

[0005] The present invention provides the following technical solutions:

[0006] A 3D printed water-cooling plate, comprising a flow channel portion and a cover portion arranged at one end of the flow channel portion; a flow channel cavity is arranged in the flow channel portion, and the flow channel cavity comprises an inlet flow channel, a first connecting flow channel, a first bending flow channel, a second bending flow channel, a second connecting flow channel, a third bending flow channel, a third connecting flow channel, a transition flow channel, a fourth bending flow channel, a fourth connecting flow channel, and an outlet flow channel arranged in sequence along a flow direction of a refrigerant;

[0007] The inlet flow channel is connected to the refrigerant inlet provided on the cover plate portion, and the outlet flow channel is connected to the refrigerant outlet provided on the cover plate portion;

[0008] A plurality of parallel guide blocks are provided in the first bending flow channel, the second bending flow channel, the third bending flow channel, and the fourth bending flow channel, and the guide blocks are used to make the refrigerant in the first bending flow channel, the second bending flow channel, the third bending flow channel, and the fourth bending flow channel flow in a "Z" shape;

[0009] The cavity wall of the flow channel cavity and the side wall of the guide block are both provided with arc sections.

[0010] The flow channel portion and the cover plate portion are integrally formed by adopting 3D printing technology.

[0011] The wall thickness of the flow channel cavity is not less than 1.2 mm.

[0012] The first bent flow channel, the second bent flow channel, the third bent flow channel, and the fourth bent flow channel are sequentially arranged side by side in the middle of the flow channel part.

[0013] The length of the flow guiding block in the third bent flow channel is greater than that in the second bent flow channel; the lengths of the flow guiding blocks in the first bent flow channel and the fourth bent flow channel are equal.

[0014] A first flow dividing block and a second flow dividing block are arranged in the inlet flow channel. The first flow dividing block and the second flow dividing block are used to make the refrigerant in the inlet flow channel flow in a "day" shape; a third flow dividing block is arranged in the outlet flow channel. The third flow dividing block is used to make the refrigerant in the outlet flow channel flow in a "square" shape; arc-shaped sections are arranged on the side walls of the first flow dividing block, the second flow dividing block, and the third flow dividing block.

[0015] A fourth flow dividing block and a fifth flow dividing block are arranged in the transition flow channel. The fourth flow dividing block and the fifth flow dividing block are used to make the refrigerant in the transition flow channel flow in a "day" shape. Arc-shaped sections are arranged on the side walls of the fourth flow dividing block and the fifth flow dividing block; the transition flow channel and the fourth bent flow channel are connected through a first branch flow channel and a second branch flow channel arranged in parallel.

[0016] Positioning holes are evenly distributed along the circumferential direction on the outer circumferential surface of the cover plate part; positioning grooves are also arranged on the outer circumferential surfaces of the flow channel part and the cover plate part; several pin holes are provided in the flow channel part and the cover plate part, and pins are inserted into the pin holes.

[0017] Heat dissipation holes that are not connected to the flow channel cavity are evenly distributed on the flow channel part and the flow channel part.

[0018] A manufacturing process for a 3D printed water cooling plate includes the following steps:

[0019] Step 1): Use a metal 3D printer to integrally print and form the flow channel part and the cover plate part to make a blank.

[0020] Step 2): Numerically control the processing of the blank, process the positioning holes, and then remove the residual material on the surface of the blank.

[0021] Step 3): Conduct an appearance inspection and remove the blanks with cracks on the surface.

[0022] Step 4): Remove the burrs on the surface of the blank, conduct a dimensional inspection, and remove the blanks with a minimum wall thickness less than 1.2 mm.

[0023] Step 5): Conduct laser marking to mark the blank.

[0024] Step 6): Conduct a flow resistance test. If the system flow resistance is less than 0.13 MPa, it is qualified.

[0025] Step 7): Perform a sealing pressure test, connect the refrigerant inlet with the water inlet pipe, connect the refrigerant outlet with the water outlet pipe, and perform a pressure test at a water pressure of 4.5MPa to remove cracked and leaking products;

[0026] Step 8): Anodize the product to improve corrosion resistance;

[0027] Step 9): Press the pin into the pin hole;

[0028] Step 10): Pack the product.

[0029] The beneficial effects of the present invention are:

[0030] The present invention maximizes the contact area between the refrigerant and the inner wall of the flow channel by changing the traditional uniform cross-section flow channel design to a uniform wall thickness and non-uniform flow channel cross-section design and adding a circular arc transition section. The present invention adopts a layout of local multi-flow channels in parallel to reduce the flow resistance of the cold plate. The present invention optimizes the flow channel connection nodes to ensure uniform heat dissipation of the cold plate as a whole and avoid excessive local temperature rise. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a stereogram of the present invention;

[0032] Figure 2 is a front view of the present invention;

[0033] Figure 3 is a rear view of the present invention;

[0034] Figure 4 is a side view of the present invention;

[0035] Figure 5 yes Figure 4 Middle AA section view;

[0036] Figure 6 yes Figure 5 Enlarged view of point A in the middle;

[0037] Figure 7 yes Figure 5 Enlarged view of point B in the middle;

[0038] Figure 8 yes Figure 5 Enlarged view of point C in the middle;

[0039] Fig. 9 yes Figure 4 Middle BB section view;

[0040] Fig.10 It is a water flow velocity test diagram of the present invention;

[0041] Fig.11 It is a water flow temperature test diagram of the present invention;

[0042] Fig.12 It is a heat transfer coefficient test diagram of the present invention;

[0043] Fig.13 It is a temperature test diagram of the cold plate temperature measuring point of the present invention;

[0044] Marked in the figure are: cover part 101, pin 102, heat dissipation hole 103, positioning hole 104, positioning groove 105, flow channel part 106, refrigerant outlet 107, refrigerant inlet 108, inlet flow channel 201, first connecting flow channel 202, first bending flow channel 203, second bending flow channel 204, second connecting flow channel 205, third bending flow channel 206, third connecting flow channel 207, transition flow channel 208, fourth bending flow channel 209, fourth connecting flow channel 210, outlet flow channel 211, first diverter block 212, second diverter block 213, third diverter block 214, first branch flow channel 215, second branch flow channel 216, fourth diverter block 217, fifth diverter block 218. DETAILED DESCRIPTION

[0045] As shown in the figure, a 3D printed water-cooled plate includes a flow channel portion 106 and a cover portion 101 disposed at one end of the flow channel portion 106. The cover portion 101 is tightly connected to one end of the flow channel portion 106. The cover portion 101 and the flow channel portion 106 are integrally formed by 3D printing technology using the X Line 1000R metal 3D printer of the German ConceptLaser company. The material of the cold plate is 6063T5. During printing, a positioning groove 105 is printed on the outer circumferential surface of the flow channel portion 106 and the cover portion 101. After printing, a number of positioning holes 104 are uniformly processed along the circumferential direction on the outer circumferential surface of the cover portion 101 by a CNC machine tool. During printing, a number of pin holes are also printed on the flow channel portion 106 and the cover portion 101. During assembly, a pin 102 is inserted into the pin hole.

[0046] When printing, the flow channel cavity is printed in the flow channel portion 106. It should be noted that the wall thickness of the flow channel cavity shall not be less than 1.2mm, so that the product meets the pressure resistance test requirements of 4.5MPa water pressure. The refrigerant can flow in the flow channel cavity. In order to reduce the weight of the cold plate and to improve the heat dissipation effect of the cold plate, heat dissipation holes 103 that are not connected to the flow channel cavity are evenly distributed on the flow channel portion 106 and the flow channel portion 106. After printing is completed, the product needs to be inspected so that the water-cooled plate has a diameter of 171mm, a height of 33.3mm, a weight of 965±20g, a bottom plate thickness of 2mm, and a minimum flow channel area of ​​10mm×5mm. Specifically, the flow channel cavity includes an inlet flow channel 201, a first connecting flow channel 202, a first bending flow channel 203, a second bending flow channel 204, a second connecting flow channel 205, a third bending flow channel 206, a third connecting flow channel 207, a transition flow channel 208, a fourth bending flow channel 209, a fourth connecting flow channel 210, and an outlet flow channel 211 which are sequentially arranged along the flow direction of the refrigerant; the inlet flow channel 201 is connected to the refrigerant inlet 108 arranged on the cover portion 101, and the outlet flow channel 211 is connected to the refrigerant outlet 107 arranged on the cover portion 101. During use, the refrigerant flows into the flow channel cavity from the refrigerant inlet 108, passes through the mouth flow channel 201, the first connecting flow channel 202, the first bending flow channel 203, the second bending flow channel 204, the second connecting flow channel 205, the third bending flow channel 206, the third connecting flow channel 207, the transition flow channel 208, the fourth bending flow channel 209, the fourth connecting flow channel 210, and the outlet flow channel 211 in sequence, and then flows out from the refrigerant outlet 107. During this process, heat exchange occurs between the refrigerant and the cold plate.

[0047] The first curved channel 203, the second curved channel 204, the third curved channel 206, and the fourth curved channel 209 are sequentially arranged side by side in the middle of the channel portion 106. A plurality of parallel guide blocks are arranged in the first curved channel 203, the second curved channel 204, the third curved channel 206, and the fourth curved channel 209. The side walls of the guide blocks and the cavity walls of the first curved channel 203, the second curved channel 204, the third curved channel 206, and the fourth curved channel 209 are all provided with arc sections. In particular, the cavity walls at the connecting nodes of each channel are provided with circular arc sections, specifically, the cavity walls at the bends of the straight channel and the single channel, such as at Figure 5 At e, the arc radius of the cavity wall is 5mm. The water flow can be diverted here through the arc cavity wall. The arc cavity wall guides the water flow, so that the water flow speed will not drop sharply. When multiple parallel flow channels are connected by a single flow channel, the bend of the single flow channel, such as Figure 5At point f, the arc radius of the cavity wall is 12mm. Since this is the bend of a single flow channel connecting multiple parallel flow channels, the water flow velocity here is greater than that of an ordinary single flow channel. Therefore, the arc radius here is larger. The drainage effect of the arc cavity wall here can keep the water flow velocity here stable. The side of each guide block and cavity wall directly opposite to the water flow direction is set as a curved surface, so that when the water flow collides with the guide block or the cavity wall, the diversion can be completed. By optimizing the flow channel connection nodes, the refrigerant can flow between the flow channels at a relatively stable flow rate, so that the overall heat dissipation of the cold plate is uniform and excessive local temperature rise is avoided. The guide blocks arranged in parallel in each curved flow channel are also provided with connection points in the middle of adjacent guide blocks. The arc radius of the connection point is 5mm, so that the effect of stabilizing the flow rate is achieved by changing the shape of the flow channel cavity. Fig.10 This is the data obtained by detecting the water flow velocity in the cold plate. It can be seen from the figure that the water flow velocity at various locations in the flow channel cavity remains basically stable. The present invention maximizes the contact area between the refrigerant and the inner wall of the flow channel by changing the traditional uniform cross-section flow channel design to a uniform wall thickness and non-uniform flow channel cross-section design, while adding an arc transition section; the present invention adopts a layout form of local multi-flow channels in parallel to reduce the flow resistance of the cold plate, thereby stabilizing the water flow velocity and keeping the water flow velocity at various locations in the flow channel cavity stable.

[0048] The guide block is used to make the refrigerant in the first curved channel 203, the second curved channel 204, the third curved channel 206, and the fourth curved channel 209 flow in a "Z" shape, so as to maximize the heat exchange area between the water flow and the cold plate. In particular, the length of the guide block in the third curved channel 206 is greater than the length of the guide block in the second curved channel 204, and the lengths of the guide blocks in the first curved channel 203 and the fourth curved channel 209 are equal. Because the water flow in the second curved channel 204 has a lower temperature and a faster flow rate, the contact area between the water flow and the cold plate here can be appropriately reduced. Since the water temperature increases after entering the third curved channel 206 through heat exchange, and the third curved channel 206 is located at a position where the temperature of the cold plate is relatively high, the heat exchange area between the water and the cold plate should be appropriately increased at the third curved channel 206, and a longer straight channel should be set at the same time, so that the water flow velocity in the third curved channel 206 is not reduced, so that the water flow in the third curved channel 206 can also complete a good heat exchange with the cold plate. In the heat transfer coefficient test performed as shown in Figure 12, it can be observed that a good heat transfer coefficient can also be maintained in the third curved channel 206.

[0049] The first flow dividing block 212 and the second flow dividing block 213 are arranged in the inlet flow channel 201. The first flow dividing block 212 and the second flow dividing block 213 are used to make the refrigerant in the inlet flow channel 201 flow in a shape like the Chinese character 'Ri' (日). The purpose of this setting is that when the water flow just enters the flow channel cavity, its velocity is relatively large, and the velocity should be appropriately reduced. At the same time, in order to increase the heat exchange area between the water flow and the cold plate in the inlet flow channel 201. The third flow dividing block 214 is arranged in the outlet flow channel 211. The third flow dividing block 214 is used to make the refrigerant in the outlet flow channel 211 flow in a shape like the Chinese character 'Kou' (口). The purpose of this setting is that the flow resistance of the water flow here will be greater than that in the inlet flow channel 201. In order to reduce the resistance and facilitate the water flow to flow out through the refrigerant outlet 107. Through the detected data, it can be determined that the above settings can achieve the corresponding technical effects. Similarly, the side walls of the first flow dividing block 212, the second flow dividing block 213, and the third flow dividing block 214, as well as the cavity walls of the outlet flow channel 211 and the inlet flow channel 201, are all provided with arc segments.

[0050] The fourth flow dividing block 217 and the fifth flow dividing block 218 are arranged in the transition flow channel 208. The fourth flow dividing block 217 and the fifth flow dividing block 218 are used to make the refrigerant in the transition flow channel 208 flow in a shape like the Chinese character 'Ri' (日). And the side walls of the fourth flow dividing block 217 and the fifth flow dividing block 218, as well as the cavity wall of the transition flow channel 208, are all provided with arc segments. The transition flow channel 208 and the fourth bending flow channel 209 are connected through the first branch flow channel 215 and the second branch flow channel 216 arranged in parallel. Since the water-cooled medium has a relatively high temperature after heat exchange through the inlet flow channel 201, the first connecting flow channel 202, the first bending flow channel 203, the second bending flow channel 204, the second connecting flow channel 205, the third bending flow channel 206, the third connecting flow channel 207, and the transition flow channel 208, at this time, the heat exchange area between the water flow and the cold plate should be increased so that the water flow can exchange heat with the cold plate better. Therefore, the first branch flow channel 215 and the second branch flow channel 216 arranged in parallel are set. At the same time, the first branch flow channel 215 and the second branch flow channel 216 are also provided with arc segments, so as to increase the heat exchange area and also play a role in stabilizing the water flow velocity.

[0051] A manufacturing process of a 3D printed water-cooled plate includes the following steps:

[0052] Step 1): Use a metal 3D printer to integrally print and form the flow channel part 106 and the cover plate part 101 to make a blank.

[0053] Step 2): Numerically control the machining of the blank to machine the positioning holes 104, and then remove the residual material on the surface of the blank.

[0054] Step 3): Conduct an appearance inspection and remove the blanks with cracks on the surface.

[0055] Step 4): Remove the burrs on the surface of the blank, conduct a dimensional inspection, and remove the blanks with the minimum wall thickness less than 1.2 mm.

[0056] Step 5): Perform laser marking to mark the blank;

[0057] Step 6): Perform a flow resistance test, and the system flow resistance is less than 0.13MPa;

[0058] Step 7): Perform a sealing pressure test, connect the refrigerant inlet 108 to the water inlet pipe, connect the refrigerant outlet 107 to the water outlet pipe, and perform a pressure test at a water pressure of 4.5 MPa to remove cracked and leaking products;

[0059] Step 8): Anodize the product to improve corrosion resistance;

[0060] Step 9): Press the pin 102 into the pin hole;

[0061] Step 10): Pack the product.

[0062] When testing the heat dissipation performance of the cold plate, mount an IGBT heating resistor on the surface of the cold plate with a power consumption of 500W±20W, use pure water at room temperature or 65# military aviation coolant as the refrigerant, and the refrigerant flow rate is 3.5±0.25L / min. After waiting for about 10 minutes for the temperature to stabilize, test the surface temperature rise of the cold plate. If the surface temperature rise of the cold plate does not exceed 8 degrees Celsius, it is qualified. Fig.11 and Fig.13 After testing, it was found that the water flow temperature was highest at the center of the cold plate, the temperature was lower in the front half near the refrigerant inlet 108, and the temperature was slightly higher in the back half near the refrigerant outlet 107; the temperature was highest at the center of the cold plate, the temperature was lower in the front half near the refrigerant inlet 108, and the temperature was slightly higher in the back half near the refrigerant outlet 107, and the temperature rise on the surface of the cold plate did not exceed 8 degrees Celsius.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. 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 3D printed water-cooled plate, characterized in that: it includes a flow channel part (106) and a cover plate part (101) provided at one end of the flow channel part (106); a flow channel cavity is provided in the flow channel part (106), and the flow channel cavity includes an inlet flow channel (201), a first connecting flow channel (202), a first bending flow channel (203), a second bending flow channel (204), a second connecting flow channel (205), a third bending flow channel (206), a third connecting flow channel (207), a transition flow channel (208), a fourth bending flow channel (209), a fourth connecting flow channel (210), and an outlet flow channel (211) arranged in sequence along the refrigerant flow direction; the inlet flow channel (201) is connected in a through manner with a refrigerant inlet (108) provided on the cover plate part (101), and the outlet flow channel (211) is connected in a through manner with a refrigerant outlet (107) provided on the cover plate part (101); a number of parallel diversion blocks are provided in each of the first bending flow channel (203), the second bending flow channel (204), the third bending flow channel (206), and the fourth bending flow channel (209), and the diversion blocks are used to make the refrigerant in the first bending flow channel (203), the second bending flow channel (204), the third bending flow channel (206), and the fourth bending flow channel (209) flow in a "Z" shape; arc-shaped sections are provided on the cavity wall of the flow channel cavity and the side wall of the diversion block; the first bending flow channel (203), the second bending flow channel (204), the third bending flow channel (206), and the fourth bending flow channel (209) are arranged side by side in the middle of the flow channel part (106) in sequence; the length of the diversion block in the third bending flow channel (206) is greater than the length of the diversion block in the second bending flow channel (204); the lengths of the diversion blocks in the first bending flow channel (203) and the fourth bending flow channel (209) are equal; a first diversion block (212) and a second diversion block (213) are provided in the inlet flow channel (201), and the first diversion block (212) and the second diversion block (213) are used to make the refrigerant in the inlet flow channel (201) flow in a "day" shape; a third diversion block (214) is provided in the outlet flow channel (211), and the third diversion block (214) is used to make the refrigerant in the outlet flow channel (211) flow in a "square" shape; arc-shaped sections are provided on the side walls of the first diversion block (212), the second diversion block (213), and the third diversion block (214); a fourth diversion block (217) and a fifth diversion block (218) are provided in the transition flow channel (208), and the fourth diversion block (217) and the fifth diversion block (218) are used to make the refrigerant in the transition flow channel (208) flow in a "day" shape, and arc-shaped sections are provided on the side walls of the fourth diversion block (217) and the fifth diversion block (218); the transition flow channel (208) and the fourth bending flow channel (209) are connected through a first branch flow channel (215) and a second branch flow channel (216) arranged in parallel.

2. The 3D printed water-cooled plate according to claim 1, characterized in that: the flow channel part (106) and the cover plate part (101) are integrally formed by 3D printing technology.

3. The 3D printed water cooling plate according to claim 1 or 2, Features: The wall thickness of the flow channel cavity is not less than 1.2 mm.

4. The 3D printed water cooling plate according to claim 1, Features: Positioning holes (104) are evenly distributed along the circumferential direction on the outer circumferential surface of the cover plate portion (101); positioning grooves (105) are also provided on the outer circumferential surfaces of the flow channel portion (106) and the cover plate portion (101); and a plurality of pin holes are provided on the flow channel portion (106) and the cover plate portion (101), and pins (102) are inserted into the pin holes.

5. The 3D printed water cooling plate according to any one of claims 1 to 4, Features: The flow channel portion (106) and the flow channel portion (106) are evenly distributed with heat dissipation holes (103) that are not connected to the flow channel cavity.

6. A process for manufacturing a 3D printed water cooling plate according to claim 1, It is characterized in that The following steps are involved: Step 1): using a metal 3D printer to integrally print the flow channel portion (106) and the cover plate portion (101) to form a blank; Step 2): CNC machining the blank to form positioning holes (104), and then removing the remaining material on the surface of the blank; Step 3): Perform appearance inspection and remove the blanks with surface cracks; Step 4): Remove burrs from the surface of the blank, perform dimensional inspection, and remove blanks with a minimum wall thickness of less than 1.2 mm; Step 5): Perform laser marking to mark the blank; Step 6): Perform a flow resistance test, and the system flow resistance is less than 0.13MPa. Step 7): Perform a sealing pressure test, connect the refrigerant inlet (108) to the water inlet pipe, connect the refrigerant outlet (107) to the water outlet pipe, perform a pressure test at a water pressure of 4.5 MPa, and remove products that are broken or leaking; Step 8): Anodize the product to improve corrosion resistance; Step 9): Press the pin (102) into the pin hole; Step 10): Pack the product.

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