Two-phase liquid cooling plate and manufacturing method

Abstract

The invention discloses a two-phase liquid cooling plate and a manufacturing method. The two-phase liquid cooling plate comprises an evaporation end, a condensation end and a plurality of fins, the evaporation end comprises a lower cover plate, a middle frame body and a plurality of capillary structures, and the lower cover plate and the middle frame body are connected to form an evaporation cavity; the condensation end comprises an upper cover plate and a middle frame body; the middle frame body comprises a frame body defined by frames and a flat plate arranged in the middle of the frame body, a plurality of groove bodies are formed in the flat plate, and the lower ends of the fins penetrate through the groove bodies and are located between the adjacent capillary structures. The welding flux in the molten state preferentially fills the gap of the matched groove body in the middle frame body, the situation that the welding flux overflows to the position below the groove body, consequently, a sintering layer is polluted, a capillary structure is damaged is reduced, and the heat dissipation efficiency and the finished product yield of the liquid cooling plate are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radiators, and in particular to a dual-phase liquid cooling plate and a manufacturing method thereof. Background Art

[0002] As we all know, high temperature is the enemy of integrated circuits. High temperature will not only cause unstable system operation and shorten service life, but may even burn some components. The function of the radiator is to absorb the heat on the chip and quickly diffuse it, thereby reducing the temperature of the chip.

[0003] At present, the working fluid of the single-phase liquid cooling plate adopts pure water or single-phase coolant, and the internal pressure resistance requirement of the liquid cooling plate is above 1Mpa. The working fluid of the two-phase liquid cooling plate adopts low-boiling point liquid such as fluorinated liquid or refrigerant, and the pressure strength needs to reach above 3Mpa. After the liquid cooling plate is close to the heat source, the heat of the heat source vaporizes the liquid working fluid into a gaseous state, and the gaseous working fluid flows upward, thereby transferring the heat from the heat source. In order to achieve two-phase changes, the existing liquid cooling plate needs to strictly evacuate and seal the internal cavity of the liquid cooling plate. The traditional welding tooth top method has a low welding yield under the requirement of 3MPa. After the solder melts, it contaminates the capillary structure of the sintered layer, affecting the performance. Therefore, how to reduce the pressure requirement of the internal cavity of the liquid cooling plate and improve the production yield of the liquid cooling plate has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0004] In view of the above-mentioned problems, the object of the present invention is to provide a dual-phase liquid cooling plate and a manufacturing method thereof. By adding a middle frame body and fins and isolating the middle frame body, the solder is molten to preferentially fill the gap in the slot body in the middle frame body to prevent the solder from overflowing to the bottom of the slot body, thereby contaminating the sintering layer and destroying the capillary structure, thereby greatly improving the heat dissipation efficiency and finished product qualification rate of the liquid cooling plate.

[0005] To achieve the above object, the present invention provides a two-phase liquid cooling plate, comprising an evaporation end, a condensation end and a plurality of fins; The evaporation end comprises a lower cover plate, a middle frame body and a plurality of capillary structures, wherein the plurality of capillary structures are parallel to each other and vertically fixed on the lower cover plate, and the lower cover plate is connected to the middle frame body to form an evaporation chamber; The condensation end includes an upper cover plate and a middle frame body; The middle frame body includes a frame body surrounded by a frame frame and a flat plate provided in the middle of the frame body, the flat plate is provided with a plurality of grooves, the lower ends of the fins pass through the grooves and are located between adjacent capillary structures, and the upper ends of the fins are located in the condensation end. The middle frame body is provided with at least one liquid inlet and one liquid outlet, and the liquid inlet, the evaporation chamber and the liquid outlet are in communication.

[0006] Preferably, the capillary structure is configured in a U shape, with its bottom connected to the lower cover plate and its top connected below the flat plate.

[0007] Preferably, the fin includes a first fin plate and a second fin plate arranged in an L shape, the first fin plate passes through the slot body and is located between two adjacent U-shaped capillary structures, the second fin plate is connected between the upper cover plate and the flat plate, and the plurality of slot bodies are distributed parallel to each other.

[0008] Preferably, a liquid is provided in the evaporation chamber, the liquid is a fluorinated liquid, the fluorinated liquid is one or more of sodium fluoride, hydrofluorocarbon, hydrofluoroether, hydrofluoroolefin, and unsaturated hydrofluoroether, the boiling point of the liquid is 47° C. to 56° C. at a standard atmospheric pressure, and the volume of the liquid accounts for 95%-100% of the volume of the evaporation chamber.

[0009] Preferably, the evaporation end further includes a joint connected to the liquid inlet and the liquid outlet.

[0010] Preferably, the liquid cooling plate is further provided with a first welding plate and a second welding plate, wherein the first welding plate is located between the upper cover plate and the upper part of the flat plate, and the second welding plate is located between the upper part of the U-shaped capillary structure and the lower part of the flat plate.

[0011] The present invention also provides a method for manufacturing a dual-phase liquid cooling plate, comprising the following steps: S1, capillary structure sintering, sintering copper mesh or copper powder on the lower cover to form a capillary structure, S2, fin installation, passing a plurality of fins through the slot of the middle frame body, so that the lower ends of the fins are located between the adjacent capillary structures, and the upper ends of the fins are located above the flat plate of the middle frame body, S3, assembly welding of the liquid cooling plate, the upper cover plate, the bent fins, the middle frame body and the lower cover plate are welded by brazing to obtain the liquid cooling plate.

[0012] Preferably, the capillary structure sintering temperature is 880-920°C, and the copper mesh or copper powder is in a semi-molten state. The brazing welding temperature is 820-870° C. The upper cover plate and the flat plate are welded by a first welding piece, and the lower cover plate and the flat plate are welded by a second welding piece. The first welding piece and the second welding piece are silver welding pieces.

[0013] Preferably, the method comprises the following steps: S11, sintering the U-shaped capillary structure, laying the copper mesh or copper powder on the U-shaped fixture for sintering, so that the capillary structure after sintering has a U-shaped cross-sectional structure, and the U-shaped bottom of the U-shaped capillary structure is sintered on the lower cover plate, S21, S21, fin bending and flattening, after step S2, the fins located above the flat plate are bent and flattened, and the bent and flattened fins are arranged into an L-shape formed by the first fin plate and the second fin plate.

[0014] The present invention also provides a dual-phase liquid cooling radiator, characterized in that it comprises a liquid cooling plate.

[0015] The beneficial effects of the present invention are as follows: the dual-phase liquid cooling plate and the manufacturing method thereof provided by the present invention, the dual-phase liquid cooling plate and the manufacturing method thereof provided by the present invention, by adding a middle frame body and fins, a flat plate is arranged inside the middle frame body, and a plurality of slots are arranged on the flat plate, through the isolation of the middle frame body, the solder is molten to preferentially fill the gap between the matching slots in the middle frame body, thereby reducing the solder overflowing to the bottom of the slot, thereby contaminating the sintering layer, destroying the capillary structure, and greatly improving the finished product qualification rate of the liquid cooling plate; by setting the capillary structure into a U shape, the bottom of the U shape is connected to the lower cover plate, the strength of the capillary structure and the liquid storage volume at the bottom of the capillary structure can be increased, thereby improving the heat dissipation efficiency of the liquid cooling plate, and there is no need to evacuate the evaporation chamber, the internal pressure requirement is not high, and only a liquid with a low boiling point needs to be used, thereby greatly improving the yield rate of the existing liquid cooling plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings illustrate exemplary embodiments of the present invention and together with the description serve to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification.

[0017] Figure 1 Schematic diagram of the structure of the dual-phase liquid cooling plate in Example 1; Figure 2 Schematic diagram of the internal structure of the dual-phase liquid cooling plate in Example 1; Figure 3 for Figure 2 A local enlarged schematic diagram of the middle A; Figure 4 Schematic diagram of the manufacturing process of the dual-phase liquid cooling plate in Example 1. DETAILED DESCRIPTION

[0018] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant contents, rather than to limit the present invention. It is also necessary to explain that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings.

[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] Embodiment 1: Please refer to Figures 1 to 4 , Embodiment 1 includes: A two-phase liquid cooling plate, including an evaporation end, a condensation end and a plurality of fins 4; The evaporation end includes a lower cover plate 1, a middle frame body 2 and a plurality of capillary structures 5. The plurality of capillary structures 5 are parallel to each other and are vertically fixed on the lower cover plate 1. After the lower cover plate 1 is connected to the middle frame body 2, an evaporation chamber 11 is formed; The condensation end includes an upper cover plate 3 and a middle frame body 2; The middle frame body 2 includes a frame surrounded by a border and a flat plate 21 provided in the middle of the frame body. A plurality of grooves 22 are provided on the flat plate 21. The lower ends of the fins 4 pass through the grooves 22 and are located between adjacent capillary structures 5. The upper ends of the fins 4 are located in the condensation end, At least one liquid inlet 61 and one liquid outlet 62 are provided on the middle frame body 2. The liquid inlet 61, the evaporation chamber 11 and the liquid outlet 62 are communicated with each other.

[0021] In the working state, the liquid cooling plate in this embodiment is connected to an external heat dissipation mechanism through the liquid inlet 61 and the liquid outlet 62 to form a radiator. The evaporation chamber 11 in this embodiment does not need to be evacuated and has low pressure requirements. Only a liquid with a lower boiling point needs to be used. Since it is communicated with the external heat dissipation mechanism, the internal liquid can be injected into the evaporation chamber 11 before use. And because the evaporation chamber 11 does not need to be evacuated and has low pressure requirements, the yield rate of the existing liquid cooling plate is greatly improved.

[0022] In this embodiment, since a liquid with a lower boiling point is used in the evaporation chamber 11, the liquid used in this embodiment is a fluorinated liquid or a refrigerant medium. The fluorinated liquid is one or more of sodium fluoride, hydrofluorocarbons, hydrofluoroethers, hydrofluoroolefins, and unsaturated hydrofluoroethers. The boiling point of the liquid under one standard atmosphere is 47°C to 56°C. The ratio of the liquid volume to the evaporation chamber volume is 95%-100%. Different from the traditional liquid cooling plate, the ratio of the liquid volume to the evaporation chamber 11 volume in this embodiment is 95%, which is significantly higher than that of the traditional liquid cooling plate. The heat source 7 is located below the lower cover plate 1. The heat of the heat source 7 is transferred to the lower cover plate 1. The low-boiling liquid boils and partially vaporizes in the evaporation chamber 11. The vaporized gas flows upward, thereby transferring the heat to the condensation end. Since the temperature of the condensation plate is lower, the vaporized gas meets the lower-temperature flat plate 21 and liquefies into a liquid again. The liquid flows downward to the lower cover plate 1 under the action of gravity and the capillary action of the capillary structure 5, and repeats the cycle, continuously circulating to transfer the heat of the heat source 7, so as to achieve the purpose of dissipating heat for the heat source 7. By passing the lower ends of the fins 4 through the grooves 22 and being located between adjacent capillary structures 5, and the upper ends of the fins 4 being located in the condensation end, the fins 4 can transfer the heat of the heat source 7 to the condensation end more quickly, thereby improving the heat dissipation efficiency of the liquid cooling plate.

[0023] In addition, in the present embodiment, by passing the fin 4 through the groove body 22 of the middle frame body 2, the design can increase the welding area of ​​the fin 4, the middle frame body 2, and the upper cover plate 3, thereby improving the overall structural strength of the condensation end. More importantly, the middle frame body 2 is isolated, and the solder in the molten state preferentially fills the gap in the middle frame body 2 that matches the groove body 22, thereby reducing the solder overflowing to the bottom of the groove body 22, thereby contaminating the sintering layer and destroying the capillary structure 5, thereby greatly improving the finished product qualification rate of the liquid cooling plate.

[0024] The capillary structure 5 is arranged in a U shape, and its bottom is connected to the lower cover plate 1, and its top is connected to the bottom of the flat plate 21. The bottom of the U shape is connected to the lower cover plate 1, which can increase the strength of the capillary structure 5. At the same time, the liquid storage volume at the bottom of the capillary structure 5 is increased, thereby improving the heat dissipation efficiency of the liquid cooling plate per unit area. The liquid will boil and vaporize in the internal space of the U shape, and multiple U shapes will separate and connect the boiling and vaporizing liquids, thereby improving the heat dissipation efficiency of the liquid cooling plate. The top of the U shape is connected to the bottom of the flat plate 21, which is conducive to the liquefied liquid flowing downward along the capillary structure 5 to the lower cover plate 1, thereby helping the liquid cooling plate to transfer heat more quickly.

[0025] The fin 4 includes a first fin plate 41 and a second fin plate 42 arranged in an L shape. The first fin plate 41 passes through the groove body 22 and is located between two adjacent U-shaped capillary structures 5. The second fin plate 42 is connected between the upper cover plate 3 and the flat plate 21. A plurality of groove bodies 22 are distributed parallel to each other. In this embodiment, the upper cover plate 3, the middle frame body 2 and the second fin plate 42 form a solid body. When heat is transferred to the condensation end, the upper cover plate 3, the middle frame body 2 and the second fin plate 42 form a solid body. In addition, in this embodiment, by passing the fin 4 through the groove body 22 of the middle frame body 2, the part above the middle frame body 2 is bent into the second fin plate 42. This design can increase the welding area of ​​the second fin plate 42, the middle frame body 2 and the upper cover plate 3, and improve the overall structural strength of the condensation end. In addition, through the isolation of the middle frame body 2, the solder is first filled in the gap of the matching groove body 22 in the middle frame body 2 in the molten state, reducing the solder overflow to the bottom of the groove body 22, thereby contaminating the sintering layer and destroying the capillary structure 5, which greatly improves the finished product qualification rate of the liquid cooling plate.

[0026] Liquid is arranged in the evaporation chamber 11. Different from the conventional liquid cooling plate, the evaporation chamber 11 in this embodiment does not need to be evacuated, and the internal pressure requirement is not high. Only liquid with a low boiling point needs to be used, which greatly improves the yield rate of the existing liquid cooling plate.

[0027] The evaporation end also includes a joint 63 connected to the liquid inlet 61 and the liquid outlet 62. In non-working conditions such as transportation, the joint 63 can protect the liquid inlet 61 and the liquid outlet 62, prevent dust or bacteria from entering the evaporation chamber 11, prevent corrosion or contamination of the liquid cooling plate, and extend the service life of the liquid cooling plate.

[0028] The liquid cooling plate is also provided with a first welding plate 81 and a second welding plate 82. The first welding plate 81 is located between the upper cover plate 3 and the top of the flat plate 21, and the second welding plate 82 is located between the top of the U-shaped capillary structure 5 and the bottom of the flat plate 21. Both the first welding plate 81 and the second welding plate 82 can use silver welding plates, which have good fluidity and can ensure sufficient welding.

[0029] The specific manufacturing method of the liquid cooling plate in this embodiment includes the following steps: S1, sintering of the capillary structure 5, sintering a copper mesh or copper powder on the lower cover plate 1 to form a capillary structure 5, S2, fin 4 installation, multiple fins 4 are passed through the slot 22 of the middle frame body 2, so that the lower end of the fin 4 is located between the adjacent capillary structures 5, and the upper end of the fin 4 is located above the flat plate 21 of the middle frame body 2. Through the isolation of the middle frame body 2, the solder in the molten state preferentially fills the gap between the slot 22 in the middle frame body 2, reducing the solder overflowing to the bottom of the slot 22, thereby contaminating the sintering layer and destroying the capillary structure 5, which greatly improves the finished product qualification rate of the liquid cooling plate. S3, assembly welding of the liquid cooling plate, the upper cover plate 3, the bent fins 4, the middle frame body 2 and the lower cover plate 1 are welded by brazing to obtain the liquid cooling plate.

[0030] The sintering temperature of the capillary structure 5 is 880-920℃, and the copper mesh or copper powder is in a semi-molten state. The brazing welding temperature is 820-870° C. The first welding piece 81 is used to weld the upper cover plate 3 and the flat plate 21 , and the second welding piece 82 is used to weld the lower cover plate 1 and the flat plate 21 . The first welding piece 81 and the second welding piece 82 are silver welding pieces.

[0031] The following steps are also included: S11, sintering the U-shaped capillary structure 5, laying the copper mesh or copper powder on the U-shaped fixture for sintering, so that the sintered capillary structure 5 has a U-shaped cross-sectional structure, and the U-shaped bottom of the U-shaped capillary structure 5 is sintered on the lower cover plate 1, S21, the fins 4 are bent and flattened, and multiple fins 4 are passed through the groove body 22 of the middle frame body 2, so that the lower ends of the fins 4 are located between adjacent capillary structures 5, and the upper ends of the fins 4 are located above the flat plate 21 of the middle frame body 2, and the fins 4 located above the flat plate 21 are bent and flattened, and the bent and flattened fins 4 are arranged into an L shape formed by the first fin plate 41 and the second fin plate 42.

[0032] Embodiment 2, a heat sink, includes the dual-phase liquid cooling plate in embodiment 1, and its heat dissipation principle is the same as that in embodiment 1, which will not be described again here.

[0033] The dual-phase liquid cooling plate provided by the present invention increases a middle frame body and fins, arranges a flat plate inside the middle frame body, arranges a plurality of slots on the flat plate, passes the lower ends of the fins through the slots, and welds the upper ends of the fins, the middle frame body, and the upper cover plate as a whole. This design can increase the welding area of ​​the fins, the middle frame body, and the upper cover plate, and improve the overall structural strength of the condensation end. In addition, through the isolation of the middle frame body, the solder in the molten state preferentially fills the gap between the matching slots in the middle frame body, reduces the solder overflow to the bottom of the slot, thereby contaminating the sintering layer and destroying the capillary structure, and greatly improves the finished product qualification rate of the liquid cooling plate; by setting the capillary structure into a U-shape, the bottom of the U-shape is connected to the lower The cover plate is connected, which can increase the strength of the capillary structure. At the same time, the liquid storage volume at the bottom of the capillary structure is increased, thereby improving the heat dissipation efficiency of the liquid cooling plate per unit area. The liquid will boil and vaporize in the internal space of the U-shaped shape, and multiple U-shaped shapes separate and connect the liquid boiling and vaporization from each other, thereby improving the heat dissipation efficiency of the liquid cooling plate. The top is connected to the bottom of the flat plate, which is conducive to the liquefied liquid flowing downward along the capillary structure to the lower cover plate, which is conducive to the liquid cooling plate to transfer heat more quickly, thereby improving the heat dissipation efficiency of the liquid cooling plate; there is no need to evacuate the evaporation chamber, and the internal pressure requirement is not high. It only needs to use liquid with a low boiling point, which greatly improves the yield rate of existing liquid cooling plates.

[0034] In summary, the dual-phase liquid cooling plate and the manufacturing method thereof provided by the present invention increase the middle frame body and the fins, set a flat plate inside the middle frame body, set a plurality of slots on the flat plate, and through the isolation of the middle frame body, the solder in the molten state preferentially fills the gap between the matching slots in the middle frame body, thereby reducing the solder overflowing to the bottom of the slot body, thereby contaminating the sintering layer and destroying the capillary structure, and greatly improving the finished product qualification rate of the liquid cooling plate; by setting the capillary structure into a U shape, the bottom of the U shape is connected to the lower cover plate, which can increase the strength of the capillary structure and the liquid storage volume at the bottom of the capillary structure, thereby improving the heat dissipation efficiency of the liquid cooling plate, and there is no need to evacuate the evaporation chamber, and the internal pressure requirement is not high, and only a liquid with a low boiling point needs to be used, thereby greatly improving the yield rate of the existing liquid cooling plate.

[0035] It should be understood by those skilled in the art that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above invention, and these changes or modifications are still within the scope of the present invention.

Claims

1. A dual-phase liquid cooling plate, characterized in that: It includes an evaporation end, a condensation end and a plurality of fins; The evaporation end comprises a lower cover plate, a middle frame body and a plurality of capillary structures, wherein the plurality of capillary structures are parallel to each other and vertically fixed on the lower cover plate, and the lower cover plate is connected to the middle frame body to form an evaporation chamber; The condensation end includes an upper cover plate and a middle frame body; The middle frame body includes a frame body surrounded by a frame frame and a flat plate provided in the middle of the frame body, the flat plate is provided with a plurality of grooves, the lower ends of the fins pass through the grooves and are located between adjacent capillary structures, and the upper ends of the fins are located in the condensation end. The middle frame body is provided with at least one liquid inlet and one liquid outlet, and the liquid inlet, the evaporation chamber and the liquid outlet are in communication.

2. The dual-phase liquid cooling plate according to claim 1, characterized in that: The capillary structure is configured in a U shape, with a bottom portion connected to the lower cover plate and a top portion connected to the lower side of the flat plate.

3. The dual-phase liquid cooling plate according to claim 2, characterized in that: The fins include a first fin plate and a second fin plate arranged in an L shape, the first fin plate passes through the slot body and is located between two adjacent U-shaped capillary structures, the second fin plate is connected between the upper cover plate and the flat plate, and a plurality of the slot bodies are distributed parallel to each other.

4. The dual-phase liquid cooling plate according to claim 1, characterized in that: A liquid is arranged in the evaporation chamber, the liquid is a fluorinated liquid, the fluorinated liquid is one or more of sodium fluoride, hydrofluorocarbon, hydrofluoroether, hydrofluoroolefin, and unsaturated hydrofluoroether, the boiling point of the liquid is 47° C. to 56° C. under a standard atmospheric pressure, and the volume of the liquid accounts for 95% to 100% of the volume of the evaporation chamber.

5. The dual-phase liquid cooling plate according to claim 1, characterized in that: The evaporation end also includes a joint connected to the liquid inlet and the liquid outlet.

6. The dual-phase liquid cooling plate according to claim 1, characterized in that: The liquid cooling plate is further provided with a first welding plate and a second welding plate, wherein the first welding plate is located between the upper cover plate and the upper part of the flat plate, and the second welding plate is located between the upper part of the U-shaped capillary structure and the lower part of the flat plate.

7. A method for manufacturing a dual-phase liquid cooling plate, characterized in that: The following steps are involved: S1, capillary structure sintering, sintering copper mesh or copper powder on the lower cover to form a capillary structure, S2, fin installation, passing a plurality of fins through the slot of the middle frame body, so that the lower ends of the fins are located between the adjacent capillary structures, and the upper ends of the fins are located above the flat plate of the middle frame body, S3, assembly welding of the liquid cooling plate, the upper cover plate, the bent fins, the middle frame body and the lower cover plate are welded by brazing to obtain the liquid cooling plate.

8. The method for manufacturing a dual-phase liquid cooling plate according to claim 7, characterized in that: The capillary structure sintering temperature is 880-920°C, and the copper mesh or copper powder is in a semi-molten state. The brazing welding temperature is 820-870° C. The upper cover plate and the flat plate are welded by a first welding piece, and the lower cover plate and the flat plate are welded by a second welding piece. The first welding piece and the second welding piece are silver welding pieces.

9. The method for manufacturing a dual-phase liquid cooling plate according to claim 7, characterized in that: The following steps are involved: S11, sintering the U-shaped capillary structure, laying the copper mesh or copper powder on the U-shaped fixture for sintering, so that the capillary structure after sintering has a U-shaped cross-sectional structure, and the U-shaped bottom of the U-shaped capillary structure is sintered on the lower cover plate, S21, fin bending and flattening. After step S2, the fins located above the flat plate are bent and flattened. The bent and flattened fins are arranged into an L-shape formed by the first fin plate and the second fin plate.

10. A two-phase liquid cooling radiator, characterized in that: It comprises a liquid cooling plate, wherein the liquid cooling plate is a dual-phase liquid cooling plate as described in any one of claims 1-6.

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