A heat spreader and its manufacturing method

Abstract

This invention discloses a heat spreader and its manufacturing method, comprising an upper cover plate, a lower cover plate, and a liquid injection pipe. The upper cover plate has multiple through holes and multiple support columns on its bottom surface. The lower cover plate has a liquid storage tank on its top surface, with an annular support step around the top of the storage tank. The upper cover plate is sealed at the opening of the storage tank and supported on the annular support step. The bottom surface of the storage tank has multiple protrusions, each with a secondary protrusion on its top surface for insertion into and sealingly connecting with the through holes. An annular step is formed between the protrusions to support the upper cover plate after the secondary protrusions are inserted into the through holes. The bottom of the storage tank is filled with a liquid-absorbing core. The support columns are inserted into the storage tank, pressing the liquid-absorbing core firmly against the bottom. One end of the lower cover plate has a liquid injection hole, and the liquid injection pipe is sealed and connected to the injection hole. This invention can achieve uniform heating at the terminal of large products, effectively reducing the maximum temperature of the product, minimizing internal temperature differences, and improving product safety and service life.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation device technology, and in particular to a heat exchange plate and its manufacturing method. Background Technology

[0002] As one of the representatives of new heat dissipation materials, vapor chambers have gradually expanded their application fields from small and micro electronic products to large products such as automotive products and data center products due to their characteristics such as fast thermal conductivity, low thermal resistance, large heat transfer capacity, good temperature uniformity and high critical heat flux density. Compared with other heat dissipation technologies, vapor chambers have obvious advantages and broad application prospects.

[0003] Vapor chambers used in large-scale products can be called ultra-large vapor chambers, and their design and manufacturing processes differ significantly from ordinary vapor chambers. Currently, vapor chamber technology for large-scale products is not mature enough to meet their heat dissipation requirements. Therefore, there is a need for a vapor chamber suitable for large-scale products to achieve their heat dissipation objectives. Summary of the Invention

[0004] The purpose of this invention is to provide a heat spreader and its manufacturing method to solve the problems existing in the prior art, so as to achieve uniform heat distribution at the terminal of large products, effectively reduce the maximum temperature of the product, reduce the internal temperature difference of the product, and improve the safety and service life of the product.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a temperature equalization plate, comprising an upper cover plate, a lower cover plate, and a liquid injection pipe. The upper cover plate has multiple through holes and multiple support columns on its bottom surface. The lower cover plate has a liquid storage tank on its top surface, and an annular support step is provided around the top of the liquid storage tank. The upper cover plate is sealed at the opening of the liquid storage tank and supported on the annular support step. The bottom surface of the liquid storage tank has multiple protrusions corresponding to each of the through holes. The top surface of each protrusion has a secondary protrusion for insertion into the through hole and sealingly connected to the through hole. An annular step is formed between the protrusions and the secondary protrusions to support the upper cover plate after the secondary protrusion is inserted into the through hole. The bottom of the liquid storage tank is filled with a liquid-absorbing core. The support columns are inserted into the liquid storage tank and press the liquid-absorbing core tightly against the bottom of the liquid storage tank. One end of the lower cover plate has a liquid injection hole communicating with the liquid storage tank, and the liquid injection pipe is sealed and connected to the liquid injection hole.

[0007] Preferably, it also includes an injection tube shield, one side of which is provided with a protective blind hole for the insertion of the injection tube, for shielding and protecting the injection tube, and the injection tube shield can be detachably connected to the lower cover plate by bolts.

[0008] Preferably, the upper cover plate has a reserved hole in the middle of its length direction, the bottom surface of the liquid storage tank has a reserved plate that mates with the reserved hole, the top surface of the reserved plate has a secondary sealing plate for inserting into the reserved hole and sealingly connecting with the reserved hole, and a reserved annular step is formed between the reserved plate and the secondary sealing plate for supporting the upper cover plate after the secondary sealing plate is inserted into the reserved hole.

[0009] Preferably, the injection hole includes an injection blind hole and an injection through hole disposed on the bottom surface of the injection blind hole and communicating with the liquid storage tank, and the injection pipe is sealed and connected in the injection blind hole.

[0010] Preferably, the top surface of the lower cover plate is provided with two liquid storage tanks, and a reinforcing rib is provided between the two liquid storage tanks. The opening of each liquid storage tank is sealed and connected to an upper cover plate.

[0011] Preferably, the through hole is a racetrack-shaped hole, and the boss and the secondary boss are racetrack-shaped bosses.

[0012] Preferably, the lower cover plate is provided with multiple bolt holes around it for use when bolting to external equipment.

[0013] Preferably, the upper cover plate and the lower cover plate are made of aluminum or aluminum alloy, and the liquid injected into the storage tank is liquid ammonia, acetone, R134a, deionized water, methanol or ethanol.

[0014] The present invention also provides a method for manufacturing the above-described heat spreader, including product formation; the product formation includes the following steps:

[0015] (1) Processing to obtain an upper cover plate and a lower cover plate with reserved processing allowance;

[0016] (2) Place the liquid-absorbing core at the bottom of the liquid storage tank of the lower cover plate obtained in step (1);

[0017] (3) Weld the upper cover plate and the lower cover plate to seal them. The welding positions are the annular support steps of the upper cover plate and the lower cover plate, as well as the periphery of the through hole on the upper cover plate and the secondary boss on the lower cover plate.

[0018] (4) Annealing and shaping to eliminate internal stress generated during welding and improve flatness;

[0019] (5) Weld the injection tube to the injection hole;

[0020] (6) Vacuum the inside of the storage tank. When the vacuum reaches the target value, inject the working medium into the storage tank. When injecting the liquid, take advantage of the low boiling point of the liquid under vacuum to heat the working medium to make it gaseous, and then inject it into the storage tank under high pressure. When the working medium reaches the target value, seal the injection pipe.

[0021] (7) The shape of the heat exchange plate is finely machined to eliminate the machining allowance of the material in step (1) and achieve the target thickness and flatness.

[0022] Preferably, sealing the injection tube in step (6) includes the following steps:

[0023] (1) Perform a cold-press sealing on the injection pipe to maintain the internal pressure of the temperature equalization plate for a period of time;

[0024] (2) The injection tube is sealed twice by argon arc welding or laser welding to form a stable long-term seal.

[0025] The present invention achieves the following technical effects compared to the prior art:

[0026] The vapor chamber and its manufacturing method provided by this invention allow for the fabrication of a vapor chamber with dimensions that can be made to a larger size to meet the requirements of large products. The working fluid inside the vapor chamber is evenly distributed throughout the storage tank under the action of the wicking core. The bottom of the lower cover plate contacts the heating object, and through heat conduction, the heat is transferred to the internal working fluid. The internal working fluid absorbs heat and turns into vapor, which rises to the upper cover plate and cools under external influences to form liquid. The liquid returns to the storage tank under gravity and is evenly distributed under the action of the wicking core. This cycle repeats continuously. This method achieves uniform temperature control of the heating object without the need for external auxiliary devices, effectively reducing the maximum temperature of the product, minimizing internal temperature differences, and improving product safety and lifespan. When used in conjunction with an external auxiliary cooling device, it enables rapid heat dissipation for large product terminals. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A top view of the heat spreader provided by the present invention;

[0029] Figure 2 This is a top view of the upper cover plate in this invention;

[0030] Figure 3 This is a bottom view of the upper cover plate in this invention;

[0031] Figure 4 This is a top view of the lower cover plate in this invention;

[0032] Figure 5 for Figure 1 Sectional view of AA in the middle;

[0033] Figure 6 for Figure 4 A magnified structural diagram of part B in the middle section;

[0034] Figure 7 This is a flowchart illustrating the manufacturing process of the heat spreader plate of this invention.

[0035] In the diagram: 1-Upper cover plate, 2-Lower cover plate, 3-Injection pipe, 4-Support column, 5-Storage tank, 6-Annular support step, 7-Through hole, 8-Boss, 9-Secondary boss, 10-Annular step, 11-Injection hole, 12-Injection pipe shield, 13-Protective blind hole, 14-Reserved hole, 15-Reserved plate, 16-Secondary sealing plate, 17-Reserved annular step, 18-Injection blind hole, 19-Injection through hole, 20-Reinforcing rib, 21-Bolt hole, 22-Reserved plate hole. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The purpose of this invention is to provide a heat spreader and its manufacturing method to solve the problems existing in the prior art, which can achieve uniform heat distribution at the terminal of large products, effectively reduce the maximum temperature of the product, reduce the internal temperature difference of the product, and improve the product safety and service life.

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] like Figures 1-7 As shown, this embodiment provides a temperature equalization plate, including an upper cover plate 1, a lower cover plate 2, and an injection pipe 3. The upper cover plate 1 has multiple through holes 7, and the bottom surface of the upper cover plate 1 has multiple support columns 4. The top surface of the lower cover plate 2 has a liquid storage tank 5, and the top of the liquid storage tank 5 has an annular support step 6. The upper cover plate 1 is sealed at the opening of the liquid storage tank 5 and supported on the annular support step 6. The bottom surface of the liquid storage tank 5 has multiple protrusions 8 corresponding to each through hole 7. The top surface of each protrusion 8 has a secondary protrusion 9 for inserting into the through hole 7 and sealingly connecting with the through hole 7. An annular step 10 is formed between the protrusion 8 and the secondary protrusion 9 to support the upper cover plate 1 after the secondary protrusion 9 is inserted into the through hole 7. The bottom of the liquid storage tank 5 is filled with a liquid absorption core. The support columns 4 are inserted into the liquid storage tank 5 and press the liquid absorption core tightly against the bottom of the liquid storage tank 5. One end of the lower cover plate 2 has an injection hole 11 that connects to the liquid storage tank 5, and the injection pipe 3 is sealed and connected to the injection hole 11.

[0040] In use, the working fluid is added to the storage tank 5 through the injection pipe 3, and then the injection pipe 3 is sealed. Under the action of the suction core, the internal working fluid is evenly distributed throughout the entire storage tank 5. The bottom of the lower cover plate 2 contacts the heating object, and through heat conduction, the heat is conducted to the internal working fluid. The internal working fluid absorbs heat and turns into vapor, which rises to the upper cover plate 1 and cools under external influences to form liquid. The liquid returns to the storage tank 5 under gravity and is evenly distributed under the action of the suction core. This cycle repeats continuously, achieving uniform temperature control of the heating object without the need for external auxiliary devices. This effectively reduces the maximum temperature of the product, minimizes the internal temperature difference, and improves product safety and service life. When used in conjunction with an external auxiliary cooling device, it can achieve rapid heat dissipation for large product terminals. The support column 4 is inserted into the storage tank 5 and presses the suction core tightly against the bottom of the storage tank 5, preventing misalignment of the suction core during use.

[0041] In this embodiment, the upper cover plate 1 has a length ranging from 200 to 3000 mm, a width ranging from 100 to 2000 mm, and a thickness ranging from 1 to 10 mm. After the upper cover plate 1 is supported on the annular support step 6, the top surface of the upper cover plate 1 is flush with the top surface of the lower cover plate 2. The secondary boss 9 and the through hole 7 are welded and fixed by friction stir welding to achieve sealing. The structural dimensions of the heat spreader can be made into a larger size as needed to meet the requirements of large products. For example, it can be made to be suitable for heat spreaders of products with dimensions of 500*500 mm or larger.

[0042] In this embodiment, a liquid injection tube shielding plate 12 is also included. A protective blind hole 13 for inserting the liquid injection tube 3 is provided on one side of the liquid injection tube shielding plate 12 to shield and protect the liquid injection tube 3. The liquid injection tube shielding plate 12 can be detachably connected to the lower cover plate 2 by bolts, which facilitates disassembly for liquid injection and drainage.

[0043] In this embodiment, a pre-drilled hole 14 is provided in the middle of the length direction of the upper cover plate 1. A pre-drilled plate 15 that mates with the pre-drilled hole 14 is provided on the bottom surface of the liquid storage tank 5. A secondary sealing plate 16 is provided on the top surface of the pre-drilled plate 15 for insertion into the pre-drilled hole 14 and for sealing connection with the pre-drilled hole 14. A pre-drilled annular step 17 is formed between the pre-drilled plate 15 and the secondary sealing plate 16 for supporting the upper cover plate 1 after the secondary sealing plate 16 is inserted into the pre-drilled hole 14. The pre-drilled plate 15 is provided with a pre-drilled plate hole 22 that runs vertically through it. The pre-drilled hole 14 and the pre-drilled plate 15 can be welded and fixed together by friction stir welding to achieve a seal. In this embodiment, the pre-drilled hole 14 is rectangular in shape, which, when matched with the pre-drilled plate 15, improves the strength of the ultra-large heat spreader and prevents it from bending easily due to its excessive length. It can also be used to support external pre-drilled support positions. In this embodiment, the reserved hole 14 is connected to the four through holes 7 on both sides, and the reserved plate 15 is integrated with the four protrusions 8 on both sides. This allows the reserved annular step 17 and the annular step 10 to connect with each other to form an irregular closed-loop step that surrounds the overall structure composed of the reserved plate 15 and the four protrusions 8. The upper cover plate 1 is supported by the irregular closed-loop step. The size, number, and shape of the reserved hole 14 can be adaptively adjusted according to the application scenario.

[0044] In this embodiment, the injection hole 11 includes an injection blind hole 18 and an injection through hole 19 connected to the liquid storage tank 5, which is disposed on the bottom surface of the injection blind hole 18. The injection pipe 3 is sealed and connected in the injection blind hole 18, and the injection pipe 3 is welded to the injection blind hole 18 by flame welding. The size of the injection pipe 3 is φ3*10mm, but it is not limited to this size.

[0045] In this embodiment, the top surface of the lower cover plate 2 is provided with two liquid storage tanks 5, and a reinforcing rib 20 is provided between the two liquid storage tanks 5. The opening of each liquid storage tank 5 is sealed to an upper cover plate 1. Each liquid storage tank 5 is connected to an injection pipe 3 through an injection hole 11. The annular support step 6 of each liquid storage tank 5 is welded to the upper cover plate 1 by friction stir welding and sealed. The reinforcing rib 20 is used to strengthen the strength of the lower cover plate 2 and can also be used to support external equipment; if the size of the ultra-large heat exchange plate is small, the reinforcing rib 20 may not be required.

[0046] In this embodiment, the through hole 7 is a racetrack-shaped hole, and the boss 8 and the secondary boss 9 are racetrack-shaped bosses. In this embodiment, the racetrack-shaped holes in the two upper cover plates 1 are arranged axially symmetrically for easy processing. The size of the racetrack-shaped holes depends on the actual application scenario; each racetrack-shaped hole can be of a different size and can be staggered. The number of rows and columns of racetrack-shaped holes can be determined according to the actual application scenario.

[0047] In this embodiment, the lower cover plate 2 is provided with multiple bolt holes 21 around it for bolting to external equipment. The bolt holes 21 are formed directly using CNC machining, and the number and diameter of the bolt holes 21 are determined according to the actual application scenario.

[0048] In this embodiment, the upper cover plate 1 and the lower cover plate 2 are made of aluminum or aluminum alloy, such as 3003 aluminum alloy; the liquid injected into the liquid storage tank 5 is liquid ammonia, acetone, R134a, deionized water, methanol or ethanol, etc.

[0049] A method for manufacturing a heat spreader as described above includes product formation; the product formation includes the following steps:

[0050] (1) Process the upper cover plate 1 and the lower cover plate 2 with a pre-reserved processing allowance; CNC machining, die casting or stamping can be used during processing; after processing, clean and degrease the upper cover plate 1 and the lower cover plate 2.

[0051] (2) The liquid absorber is laid on the bottom of the liquid storage tank 5 of the lower cover plate 2 obtained in step (1); the liquid absorber is made of aluminum mesh, sintered aluminum powder or foamed nickel, and after being cut, it is laid directly on the bottom of the liquid storage tank 5.

[0052] (3) Weld the upper cover plate 1 and the lower cover plate 2 to seal them. The welding method is friction stir welding. The welding positions are the annular support step 6 of the upper cover plate 1 and the lower cover plate 2, and the periphery of the through hole 7 on the upper cover plate 1 and the secondary boss 9 on the lower cover plate 2.

[0053] (4) Annealing and shaping to eliminate internal stress generated by welding and improve flatness; during annealing, the material is heated to 500℃ and then flattened to improve flatness and reduce deformation.

[0054] (5) Weld the injection tube 3 to the injection hole 11; Weld the injection tube 3 to the injection hole 11 by high frequency welding, flame welding and other methods; After the injection tube 3 is welded, test the inner cavity formed by the upper cover plate 1 and the lower cover plate 2 to ensure its sealing.

[0055] (6) Vacuum is drawn inside the storage tank 5. When the vacuum reaches the target value, the working medium is injected into the storage tank 5. During the injection, the working medium is heated to form a gaseous state by taking advantage of the low boiling point of the liquid under vacuum. Then, it is injected into the storage tank 5 under high pressure. When the working medium reaches the target value, the injection pipe 3 is sealed.

[0056] (7) The shape of the heat spreader is precision machined to eliminate the machining allowance of the material in step (1) and achieve the target thickness and flatness. CNC machining is used to precision machine the shape of the heat spreader.

[0057] In this embodiment, sealing the injection tube 3 in step (6) includes the following steps:

[0058] (1) Perform a cold-press sealing on the injection pipe 3 to maintain the internal pressure state of the temperature equalization plate for a period of time;

[0059] (2) The injection tube 3 is sealed twice by argon arc welding or laser welding to form a stable long-term seal.

[0060] After the product is formed, product testing is required, which includes the following steps:

[0061] (1) Test the finished product according to the actual application needs, including temperature difference test, power test, etc.; temperature difference test refers to test the temperature difference between each pair of four points on the heat dissipation surface of the heat exchange plate, namely the upper left, lower left, upper right and lower right. The maximum value of the difference between each pair is taken as the temperature difference. Generally, the temperature difference is required to be within 5℃; power test refers to heating the heat exchange plate according to the design power required by the customer and the test environment to determine whether it can achieve the heat dissipation effect expected by the customer.

[0062] (2) After the test is passed, the injection tube shield 12 and the lower cover 2 are assembled to shield and protect the injection tube 3.

[0063] The heat spreader provided by this invention can achieve uniform heat distribution in large product terminals, effectively reduce the maximum temperature of the product, reduce the internal temperature difference of the product, and improve product safety and service life; its structural size is large, which can meet the requirements of large products; it can achieve uniform temperature distribution without external auxiliary devices; and when used in conjunction with external auxiliary cooling devices, it can achieve rapid heat dissipation in large product terminals.

[0064] The product's shape can be machined using CNC automated machining, die casting, or stamping, which helps improve production efficiency and achieve mass production.

[0065] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A heat spreader, characterized in that: The device includes an upper cover plate, a lower cover plate, and an injection pipe. The upper cover plate has multiple through holes and multiple support columns on its bottom surface. The lower cover plate has a liquid storage tank on its top surface, and an annular support step is provided around the top of the liquid storage tank. The upper cover plate is sealed at the opening of the liquid storage tank and supported on the annular support step. The bottom surface of the liquid storage tank has multiple protrusions corresponding to each of the through holes. The top surface of each protrusion has a secondary protrusion for insertion into the through hole and sealing connection with the through hole. An annular step is formed between the protrusions and the secondary protrusions to support the upper cover plate after the secondary protrusion is inserted into the through hole. The bottom of the liquid storage tank is filled with a liquid-absorbing core. The support columns are inserted into the liquid storage tank and press the liquid-absorbing core tightly against the bottom of the liquid storage tank. One end of the lower cover plate has an injection hole communicating with the liquid storage tank, and the injection pipe is sealed and connected to the injection hole. The upper cover plate has a reserved hole in the middle of its length direction. The bottom surface of the liquid storage tank has a reserved plate that mates with the reserved hole. The top surface of the reserved plate has a secondary sealing plate for inserting into the reserved hole and sealingly connecting with the reserved hole. A reserved annular step is formed between the reserved plate and the secondary sealing plate to support the upper cover plate after the secondary sealing plate is inserted into the reserved hole.

2. The temperature distribution plate according to claim 1, characterized in that: It also includes an injection tube shield, which has a protective blind hole on one side for inserting the injection tube, and is used to shield and protect the injection tube. The injection tube shield can be detachably connected to the lower cover plate by bolts.

3. The temperature distribution plate according to claim 1, characterized in that: The injection hole includes an injection blind hole and an injection through hole located on the bottom surface of the injection blind hole, which communicates with the liquid storage tank. The injection pipe is sealed and connected in the injection blind hole.

4. The temperature distribution plate according to claim 1, characterized in that: The top surface of the lower cover plate is provided with two liquid storage tanks, and a reinforcing rib is provided between the two liquid storage tanks. The opening of each liquid storage tank is sealed and connected to an upper cover plate.

5. The temperature distribution plate according to claim 1, characterized in that: The through hole is a racetrack-shaped hole, and the boss and the secondary boss are racetrack-shaped bosses.

6. The temperature distribution plate according to claim 1, characterized in that: The lower cover plate is provided with multiple bolt holes for use when bolting to external equipment.

7. The temperature distribution plate according to claim 1, characterized in that: The upper cover plate and the lower cover plate are made of aluminum or aluminum alloy, and the liquid injected into the storage tank is liquid ammonia, acetone, R134a, deionized water, methanol or ethanol.

8. A method for manufacturing a heat spreader according to any one of claims 1 to 7, characterized in that, This includes product formation; the product formation includes the following steps: (1) Processing to obtain an upper cover plate and a lower cover plate with reserved processing allowance; (2) Place the liquid-absorbing core at the bottom of the liquid storage tank of the lower cover plate obtained in step (1); (3) Weld the upper cover plate and the lower cover plate to seal them. The welding positions are the periphery of the upper cover plate and the annular support step of the lower cover plate, as well as the periphery of the through hole on the upper cover plate and the secondary boss on the lower cover plate. (4) Annealing and shaping to eliminate internal stress generated during welding and improve flatness; (5) Weld the injection tube to the injection hole; (6) Vacuum the inside of the storage tank. When the vacuum reaches the target value, inject the working medium into the storage tank. When injecting the liquid, take advantage of the low boiling point of the liquid under vacuum to heat the working medium to make it form a gaseous state, and then inject it into the storage tank under high pressure. When the working medium reaches the target value, seal the injection pipe. (7) The shape of the heat exchange plate is finely machined to eliminate the machining allowance of the material in step (1) and achieve the target thickness and flatness.

9. The method for manufacturing a heat spreader according to claim 8, characterized in that: Step (6) of sealing the injection tube includes the following steps: (1) Perform a cold-press sealing on the injection pipe to maintain the internal pressure state of the temperature equalization plate for a period of time; (2) The injection tube is sealed twice by argon arc welding or laser welding to form a stable long-term seal.

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