Combined heat pipe and its processing method, and heat dissipation module

Abstract

The application provides a combined heat pipe, a processing method thereof and a heat dissipation module. The combined heat pipe comprises a base heat pipe and an external heat pipe. The base heat pipe is integrally formed, and the base heat pipe is provided with an evaporation section and a condensation section. The evaporation section and the condensation section are in communication with each other, that is, at least one end of the evaporation section is in communication with the condensation section. The base heat pipe is provided with a mounting hole. The external heat pipe is provided with an open end and a closed end. The open end of the external heat pipe is welded with the mounting hole, so that the inside of the external heat pipe and the inside of the base heat pipe are in communication with each other. The processing method is used for processing and manufacturing the combined heat pipe. The heat dissipation module comprises the combined heat pipe. The combined heat pipe, the processing method thereof and the heat dissipation module can increase the heat exchange area through simple structure design without changing the overall size of the heat pipe, so as to improve the overall heat dissipation performance of the heat pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of heat dissipation technology, in particular to a combined heat pipe and its processing method and heat dissipation module. BACKGROUND

[0002] The heat dissipation module mainly comprises a heat pipe and a heat dissipation fin. The existing heat pipe mainly comprises a closed metal pipe body, a capillary core structure inside the metal pipe body and a heat transfer fluid filled in the metal pipe body, and a proper vacuum degree is maintained in the metal pipe body to reduce the heat pipe starting temperature difference. The evaporation end of the heat pipe is arranged at the heat source, so that the heat generated by the heat source evaporates and absorbs heat to vaporize the fluid (liquid phase) in the pipe (vapor phase), and the generated steam is driven by the steam pressure difference to flow to the condensing part of the heat pipe. The steam releases latent heat at the condensing part and returns to the evaporation part through the capillary core structure, that is, through the above structure, the heat is quickly conducted away. Due to the simple structure of the heat pipe and the advantages of high conduction performance and low thermal resistance, the heat pipe has been applied to the field of electronic or other heat dissipation.

[0003] In a common tower type heat sink, a U-shaped heat pipe 20 is generally used, and its structure is shown in Figure 1 Such U-shaped heat pipe 20 needs to be bent into shape. However, due to the capillary core structure inside the heat pipe, the bending radius at the corner is relatively limited when bending, which limits the width of the whole heat pipe. Therefore, there is a blank area 21 in the middle of the U-shaped heat pipe. Due to the lack of heat pipe as a medium, the heat transfer efficiency of the blank area 21 is low, thereby limiting the heat dissipation performance of the U-shaped heat pipe 20 and the heat sink.

[0004] Therefore, how to design a combined heat pipe and its processing method and heat dissipation module, which can increase the heat exchange area and improve the heat dissipation performance through simple structure design without changing the overall size of the heat pipe. SUMMARY

[0005] In view of the shortcomings of the prior art, the present application provides a combined heat pipe and its processing method and heat dissipation module, which can increase the heat exchange area and improve the heat dissipation performance through simple structure design without changing the overall size of the heat pipe.

[0006] The purpose of the present application is achieved by the following technical scheme:

[0007] A combined heat pipe comprises a base heat pipe and an external heat pipe.

[0008] The base heat pipe is an integral structure, and the base heat pipe is provided with an evaporation section and a condensation section, and the evaporation section and the condensation section are in communication with each other, that is, at least one end of the evaporation section is in communication with the condensation section.

[0009] The base heat pipe is provided with a mounting hole, and the external heat pipe is provided with an open end and a closed end. The open end of the external heat pipe is welded with the mounting hole, so that the interior of the external heat pipe and the interior of the base heat pipe are in communication with each other.

[0010] In one of the embodiments, the base heat pipe and the interior of the external heat pipe are both provided with a capillary core structure and working fluid, the working fluid circulates and realizes heat transfer in the interiors of both; when the external heat pipe is welded with the base heat pipe, the capillary core structures of both are connected with each other, and the working fluid can flow between the base heat pipe and the external heat pipe.

[0011] In one of the embodiments, the shells of the base heat pipe and the external heat pipe are made of copper material, aluminum material, copper alloy or aluminum alloy.

[0012] In one of the embodiments, the external heat pipe is in a cylindrical structure, the base heat pipe is in a U-shaped structure, the connecting part of the evaporation section and the condensation section forms an angle, the evaporation section is in a flat structure, and the condensation section is in a cylindrical structure.

[0013] In one of the embodiments, the open end of the external heat pipe is provided with at least one notch, the notches are oppositely arranged and form a channel, when the external heat pipe is welded with the base heat pipe, the open end is inserted into the interior of the base heat pipe from the mounting hole, and the channel is used to ensure that the interior of the base heat pipe remains in communication.

[0014] A processing method for processing the combined heat pipe, which comprises the following steps:

[0015] Preparation of the main body of the base heat pipe and the external heat pipe;

[0016] At least one mounting hole is arranged on the main body of the base heat pipe;

[0017] One end of the external heat pipe is inserted into the mounting hole of the base heat pipe, and the two are combined and fixed by welding.

[0018] In one of the embodiments, at least one end of the main body is an open end, or both ends are open ends.

[0019] In one of the embodiments, at least one end of the base heat pipe or the external heat pipe is a closed end, and the other end is provided with an injection pipe. Compressed gas is injected into the interior of the main body through the injection pipe, so that the interior of the main body is under high pressure; and the mounting hole is obtained by laser cutting.

[0020] In one of the embodiments, a gas pressure monitoring device is included, which monitors the gas pressure in the main body in real time when the compressed gas is injected; and the laser cutting is stopped when a sudden drop of the gas pressure in the main body is monitored.

[0021] In one of the embodiments, after the laser welding is completed, the compressed gas is injected into the main body again, and the gas pressure monitoring device is used to monitor in real time to verify the welding air tightness.

[0022] In one of the embodiments, a CCD vision module is included in the step, which determines the direction of the external heat pipe by recognizing the position of the gap; and a mechanical arm is used to clamp the external heat pipe and adjust the direction of the external heat pipe.

[0023] In one of the embodiments, a fixing jig is included in the step, which includes a base, a floating table, a pressing clamp, a clamping cylinder and a driving motor; the floating table is rotatably arranged on the base, the main body is fixed on the floating table by the pressing clamp, the driving motor is used to drive the floating table to swing, and the clamping cylinder is fixed on the floating table and used to clamp the external heat pipe.

[0024] In one of the embodiments, when the external heat pipe is inserted into the mounting hole of the base heat pipe and fixed by welding, the welding can be laser welding, CO2 welding or brazing.

[0025] In one of the embodiments, the working fluid is filled in one step, and the corresponding port of the main body is closed.

[0026] The application further discloses a heat dissipation module, which includes the combined heat pipe.

[0027] In one of the embodiments, the injection pipe is cut off in one step.

[0028] In summary, the combined heat pipe, the processing method thereof and the heat dissipation module can increase the heat exchange area and improve the overall heat dissipation performance of the heat pipe without changing the overall size of the heat pipe through simple structural design. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiments will be briefly introduced below.

[0030] Figure 1 A structural schematic view of a U-shaped heat pipe related to the background art;

[0031] Figure 2 A structural diagram of a combined heat pipe according to the present application;

[0032] Figure 3 A structural diagram of a combined heat pipe according to the present application; Figure 2 A structural exploded diagram of a combined heat pipe according to the present application;

[0033] Figure 4 A diagram of a combined heat pipe according to the present application;

[0034] Figure 5 A diagram of a combined heat pipe according to the present application;

[0035] Figure 6 A diagram of a combined heat pipe according to the present application;

[0036] Figure 7 A diagram of a combined heat pipe according to the present application; DETAILED DESCRIPTION

[0037] For the purpose of promoting an understanding of the principles of the application, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the application is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the application as illustrated therein being contemplated as within the scope of the application. The application disclosed is a best embodiment thereof.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this description of the application, the following terms are defined with the following meanings:

[0039] The present application provides a combined heat pipe 10, as shown in Figure 2 and Figure 3 which includes a base heat pipe 110 and an external heat pipe 120.

[0040] The base heat pipe 11 is integrally formed, and the base heat pipe 110 is provided with an evaporation section 111 and a condensation section 112. The evaporation section 111 and the condensation section 112 are in communication with each other, that is, the evaporation section 111 has at least one end in communication with the condensation section 112.

[0041] As shown in Figure 3 The base heat pipe 110 is provided with a mounting hole 114, the external heat pipe 120 is provided with an open end 121 and a closed end 122, and the open end 121 of the external heat pipe 120 is welded to the mounting hole 114, so that the interior of the external heat pipe 120 and the interior of the base heat pipe 110 are in communication with each other, thereby forming an integral whole.

[0042] In the embodiment, as shown in Figure 2 and Figure 3 The base heat pipe 11 is in a U-shaped structure (the embodiment is described by taking the U-shaped structure as an example, but is not limited thereto), the number of the condensation sections 112 is two, the two condensation sections 112 are respectively located on the two sides of the evaporation section 111, and the connecting portions of the evaporation section 111 and the condensation sections 112 form corners 113. In the embodiment, the condensation sections 112 are in a cylindrical structure, and the structure of the external heat pipe 120 is similar to that of the condensation sections 112, and both are in a cylindrical structure. The evaporation section 111 is in a flat structure, and the evaporation section 111 in the flat structure can have a larger contact area when in contact with a heat source such as a chip, thereby obtaining better heat exchange performance. Of course, the evaporation section 111 and the condensation sections 112 can be both flat or cylindrical, and are not limited thereto.

[0043] The interiors of the base heat pipe 110 and the external heat pipe 120 are both provided with a capillary structure and a working fluid (similar to the heat pipe of the prior art), and the working fluid circulates in the interiors of the base heat pipe 110 and the external heat pipe 120 in a two-phase flow mode to achieve heat transfer. When the external heat pipe 120 is welded to the base heat pipe 110, the capillary structures of the base heat pipe 110 and the external heat pipe 120 are connected to each other, so that the working fluid can flow between the base heat pipe 110 and the external heat pipe 120, that is, the evaporation section 111 of the base heat pipe 110 is also an evaporation area of the external heat pipe 120, and the external heat pipe 120 itself plays the same condensation and heat dissipation role as the condensation section 112.

[0044] In the prior art, because the heat pipe has a capillary structure in the interior, the bending radius of the corner portion is relatively limited when bending, thereby limiting the width of the whole heat pipe (the U-shaped heat pipe 20). Therefore, there is a blank area 21 in the middle of the U-shaped heat pipe (as shown in Figure 1As shown in the figure). Due to the lack of heat pipe as a medium, the heat transfer efficiency of this area is low, thereby limiting the heat dissipation performance of the U-shaped heat pipe 20 and the heat sink. That is, in the plane where the U-shaped heat pipe 20 is located, although the U-shaped heat pipe 20 occupies a large area as a whole, the actual effective heat dissipation area is limited. The existing tower heat sink usually increases the number of U-shaped heat pipes 20 and adds fins to improve the heat dissipation performance, which also increases the size and cost of the heat sink.

[0045] Compared with the prior art, the present application welds the external heat pipe 120 to the base heat pipe 110 by laser welding, which is equivalent to adding the number of condensation branch pipes to the existing U-shaped heat pipe 20. In this way, the blank area 21 of the prior art is filled, and the effective heat dissipation area of the heat pipe is increased, thereby improving the overall heat dissipation performance of the heat pipe.

[0046] Preferably, the base heat pipe 110 and the shell of the external heat pipe 120 are both made of copper material, which has high heat transfer efficiency, large heat capacity and good corrosion resistance. The copper material heat pipe also includes plated copper heat pipe and single crystal copper heat pipe and other variants. Of course, the shell of the base heat pipe 110 and the external heat pipe 120 can also be made of one or a combination of aluminum material, copper alloy or aluminum alloy.

[0047] In the present embodiment, the open end 121 of the external heat pipe 120 is provided with at least one notch 123 (as shown in the figure). Figure 3 When the external heat pipe 120 is welded with the base heat pipe 110, the open end 121 is inserted into the inside of the base heat pipe 110 from the mounting hole 114, and the channel is used to ensure that the inside of the base heat pipe 110 remains connected.

[0048] It should be noted that whether the notch 123 is provided or not will affect the connection relationship between the external heat pipe 120 and the evaporation section 111. Specifically, if the notch 123 is not provided, when the external heat pipe 120 is inserted, the open end 121 will be inserted into the inside of the evaporation section 111, which will cause the air passage inside to be blocked, so in the case where the notch 123 is not provided, the open end 121 can only be combined with the edge of the mounting hole 114 (as shown in the figure), and it cannot be inserted into the inside of the evaporation section 111. After the notch 123 is provided, the external heat pipe 120 can be directly inserted into the inside of the evaporation section 111 (as shown in the figure), and the air passage inside the external heat pipe 120 can still be unblocked through the channel formed by the notch 123, so it will not be blocked. Figure 4 Figure 5

[0049] ​​In comparison, the way of directly inserting the external heat pipe 120 into the inside of the evaporation section 111 can be more beneficial to realize the internal heat exchange. Because after the insertion, the capillary structure of the external heat pipe 120 also penetrates into the inside of the evaporation section 111 and contacts with the capillary structure of the evaporation section 111 in a large area, so that the internal working fluid can flow smoothly. If the external heat pipe 120 is not inserted into the inside of the evaporation section 111, the contact area of the capillary structures in the two is small, which will limit the flow of the internal working fluid. That is, the way of direct insertion can improve the heat exchange efficiency of the heat pipe after welding.

[0050] At the same time, the way of direct insertion is also beneficial to welding, because after the insertion, the mounting hole 114 has a limiting effect on the external heat pipe 120, so that the external heat pipe 120 will not be dislocated with the mounting hole 114 during the welding process. If it cannot be inserted, the open end 121 of the external heat pipe 120 can only be supported on the edge of the mounting hole 114, which leads to the open end 121 being easily dislocated with the mounting hole 114 during the welding process.

[0051] The present application also provides a processing method for processing the combined heat pipe 10, which mainly comprises the following steps:

[0052] First, the main body sketch 110' (as shown in Figure 6 ) of the base heat pipe 110 and the external heat pipe 120 are prepared;

[0053] Then, at least one mounting hole 114 is formed on the main body sketch 110' of the base heat pipe 110;

[0054] Finally, one end of the external heat pipe 120 is inserted into the mounting hole 114 of the base heat pipe 110, and the two are combined and fixed by welding.

[0055] Among them, at least one end of the main body sketch 110' is an open end or both ends are open ends. Preferably, at least one end of the base heat pipe 110 or the external heat pipe 120 is a closed end, and the other end is provided with an injection pipe 115, through which compressed gas can be injected into the inside of the main body sketch 110', so that a high pressure is formed in the inside of the main body sketch 110'; the mounting hole 114 is obtained by laser cutting.

[0056] During the laser cutting process, the method has a gas pressure monitoring instrument (not shown in the figure), after the compressed gas is injected into the main body sketch 110', the gas pressure monitoring instrument monitors the gas pressure in the main body sketch 110' in real time. When it is monitored that the gas pressure in the main body sketch 110' drops suddenly, it means that the mounting hole 114 is cut and formed, then the laser cutting is stopped to avoid cutting the capillary structure in the inside of the evaporation section 111. The specific cutting process and principle are as follows:

[0057] Before cutting, compressed air is injected into the inside of the main body 110' through the injection pipe 115, so that the inside of the main body 110' is always maintained in a high pressure state during the cutting process, and the high pressure gas inside has an outward thrust on the shell. During cutting, the laser cuts along a circular trajectory on the surface of the evaporation section 111, and the laser does not directly penetrate the shell of the evaporation section 111, but continuously reduces the thickness of the shell (i.e. cuts out a groove). When the thickness is reduced to be insufficient to resist the gas pressure, fracture will occur, thereby forming the mounting hole 114, and the high pressure gas in the inside of the main body 110' will be quickly discharged from the mounting hole 114, causing the air pressure in the main body 110' to drop rapidly. After the air pressure monitoring instrument detects the rapid drop in air pressure, the laser is immediately stopped to prevent the laser from irradiating the inside of the evaporation section 111 and causing damage to the capillary structure; at the same time, the high pressure gas discharge will blow away the excess material and debris generated during cutting, thereby preventing the excess material and debris from falling into the inside of the evaporation section 111.

[0058] Preferably, the air pressure monitoring instrument can also be applied to other steps to check the sealing degree of laser welding. After laser welding is completed, compressed air is again injected into the inside of the main body 110', and is maintained for a period of time, during which real-time monitoring is performed by the air pressure monitoring instrument. If the air pressure in the main body 110' does not decrease during this period, it indicates that the welding air tightness of the open end 121 and the mounting hole 114 is good.

[0059] In the present embodiment, a CCD vision module and a mechanical arm (not shown in the figure) are also applied. The CCD vision module determines the direction of the external heat pipe 120 by identifying the position of the gap 123, and the mechanical arm is used to clamp the external heat pipe 120 and adjust the direction of the external heat pipe 120. Through the cooperation of the CCD vision module and the mechanical arm, the open end 121 of the external heat pipe 120 can be accurately inserted into the mounting hole 114, and the open end 121 will not block the air passage inside the evaporation section 111 after it is inserted into the evaporation section 111. Preferably, the mechanical arm can use a seven-axis torque collaborative robot of the prior art, which uses a six-dimensional pressure sensor to control the force accuracy, thereby achieving angle adjustment and control of the insertion force of the external heat pipe 120.

[0060] In the present embodiment, the method includes a fixing jig 30. As shown in Figure 7 the fixing jig 30 includes a base 31, a floating table 32, a pressing clamp 33, a clamping cylinder 34, and a driving motor 35. The floating table 32 is rotatably arranged on the base 31, the main body 110' is fixed to the floating table 32 by the pressing clamp 33, the driving motor 35 is used to drive the floating table 32 to swing and rotate, the clamping cylinder 34 is fixed to the floating table 32, and the clamping cylinder 32 is used to clamp the external heat pipe 120.

[0061] In operation, the worker installs the main body 110' on the floating platform 32 and fixes it with the pressing clamp 33; the laser is above the fixed jig 30 and emits laser, the driving motor 35 drives the floating platform 32 to swing within an angle range of 45 degrees left and right, so that the laser can irradiate the edge of the installation hole 114, thereby completing the laser cutting or laser welding work. The holding cylinder 34 moves with the floating platform 32, in the method, the holding cylinder 34 temporarily clamps the external heat pipe 120 which has not been welded and fixed, so as to ensure that the external heat pipe 120 moves synchronously with the main body 110', and prevent the external heat pipe 120 from being skewed or falling during the deflection of the floating platform 32.

[0062] After the external heat pipe 120 is combined and fixed with the base heat pipe 110, the working fluid is filled into the main body 110' through the injection pipe 115. Then the injection pipe 115 is cut off, and the corresponding port of the main body 110' is closed. In this way, the main body 110' is processed into the base heat pipe 110, and the base heat pipe 110 and the external heat pipe 120 complete welding to form the combined heat pipe 10 of the application.

[0063] In the welding process, the welding of the method can be laser welding, CO2 welding or brazing.

[0064] Compared with the existing laser cutting technology, the laser cutting method of the application has the following advantages:

[0065] Firstly, it has a clear feedback signal, that is, the internal air pressure value of the main body 110', so that the machine equipment can clearly judge whether the cutting is in place, and stop the laser in time, thereby avoiding damaging the capillary structure in the evaporation section 111;

[0066] Secondly, the laser cutting is flat and consistent, which lays a foundation for the subsequent splicing process of the external heat pipe 120;

[0067] Thirdly, the excess material and debris generated by laser cutting will be blown away by the high-pressure gas, thereby preventing the excess material and debris from falling into the evaporation section 111, and avoiding the pollution of the inner cavity.

[0068] The application also provides a heat dissipation module, which comprises the combined heat pipe 10. The heat dissipation module further comprises a heat dissipation fin, which is sleeved on the combined heat pipe 10.

[0069] In summary, the combined heat pipe, the processing method thereof and the heat dissipation module of the application can increase the heat exchange area and improve the overall heat dissipation performance of the heat pipe without changing the overall size of the heat pipe through simple structural design.

[0070] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A combined heat pipe, characterized by The base heat pipe and the external heat pipe are connected by welding. The base heat pipe is integrally formed and has an evaporation section and a condensation section, the evaporation section and the condensation section are in communication with each other, and at least one end of the evaporation section is in communication with the condensation section. The base heat pipe has a mounting hole, the external heat pipe has an open end and a closed end, and the open end of the external heat pipe is welded to the mounting hole, so that the interior of the external heat pipe and the interior of the base heat pipe are in communication with each other. The interiors of the base heat pipe and the external heat pipe are provided with capillary structures and working fluids, the working fluids circulate in the interiors of the base heat pipe and the external heat pipe and realize heat transfer, the capillary structures of the base heat pipe and the external heat pipe are connected to each other after the base heat pipe and the external heat pipe are welded, and the working fluids can flow between the base heat pipe and the external heat pipe. The external heat pipe is in a cylindrical structure, the base heat pipe is in a U-shaped structure, the connection between the evaporation section and the condensation section forms a corner, the evaporation section is in a flat structure, and the condensation section is in a cylindrical structure. The open end of the external heat pipe has at least one notch, the notches are oppositely arranged and form a channel, the open end of the external heat pipe is inserted into the interior of the base heat pipe from the mounting hole when the base heat pipe and the external heat pipe are welded, and the channel is used to ensure that the interior of the base heat pipe remains in communication.

2. The combined heat pipe according to claim 1, wherein The shells of the base heat pipe and the external heat pipe are made of copper or aluminum.

3. A method of processing, characterized by, A method for manufacturing the combined heat pipe is provided, and the method comprises the following steps: Preparation of a main body of the base heat pipe and the external heat pipe; At least one mounting hole is formed in the main body of the base heat pipe; One end of the external heat pipe is inserted into the mounting hole of the base heat pipe, and the base heat pipe and the external heat pipe are combined and fixed by welding.

4. The method of claim 3, wherein At least one end of the main body is an open end.

5. The method of claim 3, wherein At least one end of the base heat pipe or the external heat pipe is a closed end, and the other end is provided with an injection pipe, compressed gas is injected into the interior of the main body through the injection pipe, the interior of the main body is formed into high pressure, and the mounting hole is obtained by laser cutting.

6. The method of claim 5, wherein, The gas pressure monitoring instrument is used to monitor the gas pressure in the main body in real time when the compressed gas is injected, and laser cutting is stopped when the gas pressure in the main body is monitored to be suddenly reduced.

7. The method of claim 6, wherein, After laser welding is completed, the compressed gas is injected into the interior of the main body again, and the welding airtightness is verified by real-time monitoring of the gas pressure monitoring instrument.

8. The method of claim 3, wherein A CCD vision module and a mechanical arm are used in the step, the direction of the external heat pipe is determined by identifying the position of the notch by the CCD vision module, and the mechanical arm is used to clamp the external heat pipe and adjust the direction of the external heat pipe.

9. The method of claim 3, wherein, In the step, a fixing jig is included, which comprises a base, a floating table, a pressing clamp, a holding cylinder and a driving motor. The floating table is rotatably arranged on the base. The main body prototype is fixed on the floating table by the pressing clamp. The driving motor is used to drive the floating table to swing. The holding cylinder is fixed on the floating table and used to hold the external heat pipe.

10. The method of claim 3, wherein In the step, one end of the external heat pipe is inserted into the mounting hole of the base heat pipe, and the two are combined and fixed by welding. The welding is laser welding, CO2 welding or brazing.

11. The method of claim 5, wherein, In the step, the working fluid is filled, and the corresponding port of the main body prototype is closed.

12. The method of claim 11, wherein, In the step, the injection pipe is cut off.

13. A heat dissipation module, characterized in that, The combined heat pipe of any one of claims 1-2 is included.

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