TWI809346B - Flexible heat dissipation device - Google Patents

Abstract

A flexible heat dissipation device includes an evaporator, a vapor tube, a liquid tube and a condenser. The evaporator has at least one vapor chamber. A capillary structure and a working fluid are received in the vapor chamber. One end of the vapor tube is in communication with one end of the evaporator. The other end of the vapor tube is in communication with the condenser. Two ends of the liquid tube are respectively in communication with the evaporator and the condenser, whereby the evaporator, the vapor tube, the condenser and the liquid tube form a loop for the working fluid to flow through. At least one bellows section is disposed on one or both of the vapor tube and the liquid tube. The bellows section has multiple waved stripes. More than one of the heights, widths and pitches of the multiple waved stripes are equal to or unequal to each other.

Description

flexible cooling device

The invention relates to a flexible heat dissipation device, in particular to a flexible heat dissipation device capable of achieving bending effect and absorbing bridging force of pipelines.

With the continuous improvement of the power of electronic components such as central processing units, the problem of heat dissipation has been paid more and more attention by people. The loop heat pipe is used as an effective heat transfer element in the field of heat dissipation due to its efficient heat conduction performance.

Generally, the current common loop heat pipe includes an evaporating part, a condensing part, and a vapor pipe and a liquid pipe arranged between the evaporating part and the condensing part. The steam pipe and the liquid pipe connect the evaporation part and the condensation part to form a circuit, and the circuit is filled with pure water. The evaporating part is connected with a heating element (such as a central processing unit or a graphics processing unit). When the evaporating part of the loop heat pipe absorbs heat from the heating element and is heated, the pure water in it absorbs the heat and evaporates and expands into a gaseous state, flows through the steam pipe to the condensation part of the loop heat pipe, and releases heat in the condensation part, condenses and shrinks into a gaseous state. In liquid state, the condensed working medium returns to the evaporation part through the liquid pipe to complete a cycle. In this way, the pure water evaporates and condenses repeatedly, absorbing and releasing heat continuously, so as to achieve the purpose of heat exchange. However, since the heating element on the motherboard in the electronic device (such as a server or a communication box) is surrounded by a plurality of electronic components (such as capacitors, transistors, resistors, inductors), and there will be a gap between the heating element and other surrounding electronic components. The height difference makes the steam pipe and liquid pipe of the heat pipe of this circuit must be designed in advance Dodging and bypassing the multiple electronic components on the main board can allow space for the steam pipe, liquid pipe and condensing part to be placed, so that the loop heat pipe cannot be applied to various specifications or models of main boards, and because the steam pipe and the liquid pipe are for Dodging bypassing the relationship of a plurality of electronic components poses a problem of cost increase. In addition, the flatness of the outer surface of the evaporator attached to the heating element is not on the same level as the flatness of the outer surface of the condensing part assembled on a fixed platform, and the evaporating part and the condensing part are connected through Inflexible (non-bendable) non-flexible metal (welded through straight copper pipes) steam pipes and liquid pipes are connected to these pipes and the distance between the pipes is long, so that the evaporating part and the condensing part are assembled on a plane The degree is difficult to control. If the evaporator and the condensing part are hard-assembled at two positions (that is, the heating element and the fixed platform) have different flatness, it will cause the bridging force generated by the aforementioned pipeline to pull the evaporating part and the condensing part. However, the contact surface of the evaporating part and the heating element cannot be in good contact with each other, and the contact surface of the condensing part with the fixed platform cannot be in perfect contact with each other.

An object of the present invention is to provide a flexible heat dissipation device capable of bending and absorbing bridging force of pipelines.

Another object of the present invention is to provide an assembly that allows an evaporator and a heating element to be in perfect flat contact with each other, and a condenser and a member in an electronic device to have a perfectly flat contact surface. Flexible heat sink with sticky contact.

Another object of the present invention is to provide a method that utilizes either or both of a steam pipe and a liquid pipe to be provided with at least one corrugated section. By setting the corrugated section, it can be bent and deformed at any angle or direction, so that the vapor Tubes and condensing tubes are flexible heat dissipation devices that can be assembled, aligned and adjusted for height differences corresponding to evaporators, condensers, heating elements and components.

To achieve the above object, the present invention provides a flexible cooling device, comprising an evaporator, a vapor pipe, a condenser and a liquid pipe, the evaporator has at least one vapor chamber, a liquid inlet and a vapor outlet , the vapor chamber accommodates at least one capillary structure and a working fluid, the liquid inlet and the vapor outlet respectively communicate with the vapor chamber, one end of the vapor pipe communicates with the vapor outlet, and the other end of the vapor pipe communicates with the condensation The two ends of the liquid pipe are respectively connected to the evaporator and the condenser, so that the evaporator, the steam pipe, the condenser and the liquid pipe form a circuit of the working fluid, and at least one corrugated section is arranged between the vapor pipe and the For either or both of the liquid pipes, the corrugated section has a plurality of corrugations, and one or more of the height, width and spacing of the plurality of corrugations are the same or different from each other.

The present invention further provides a flexible heat dissipation device, which includes an evaporator, at least one corrugated section and a vapor-liquid return pipe, the evaporator has a vapor chamber, a liquid inlet and a vapor outlet, and the vapor chamber accommodates a capillary structure and a working fluid, the liquid inlet and the steam outlet are connected to the steam chamber respectively, the vapor-liquid return pipe is provided with a steam section and a liquid section, and one end of the steam section and the liquid section is respectively connected to the steam outlet and the The liquid inlet, the other end of the steam section is integrally extended outward and connected to the other end of the liquid section to form a condensation section, and a condensation element is arranged outside the condensation section, and at least one corrugated section is arranged on the vapor section and the liquid section Either or both, and the corrugated section has a plurality of corrugations, and more than one of the width, height and spacing of the plurality of corrugations is the same or different from each other.

The above-mentioned liquid pipe is provided with a capillary structure of the pipe body, and the capillary structure of the pipe body is arranged on the inner surface of the liquid pipe.

Through the design of the above-mentioned embodiments of the present invention, the effect of bending (bending) and absorbing the bridging force of the pipeline can be achieved, and it can also be applied to circuits in various electronic devices (such as servers, computers or communication boxes). Electronic components with different heights on the board are used to effectively make the evaporator closely fit the heating element.

1: Flexible cooling device

11: Evaporator

111: shell

112: steam channel

113: Vapor chamber

114: capillary structure

115: Liquid inlet

116: steam outlet

12: Steam pipe

124, 144: outer surface

125, 145: inner surface

13: Condenser

131: steam inlet

132: liquid outlet

133: Vapor-liquid mixing channel

134: cooling fins

14: Liquid pipe

15: straight section

16: corrugated section

161: Ripple

1611: corrugated top

1612: Corrugated bottom

181: Spacing

2: Vapor-liquid return pipe

21: steam section

22: Liquid section

23: Condensation section

X: height

Y: width

3: Condensing element

4: Circuit board

41: Electronic components

42: heating element

FIG. 1A is a three-dimensional assembly diagram of the flexible heat dissipation device according to the first embodiment of the present invention.

FIG. 1B is a schematic cross-sectional view of the flexible heat sink according to the first embodiment of the present invention.

Fig. 1C is a partially enlarged schematic diagram of the section of the steam pipe and the liquid pipe in Fig. 1B of the present invention.

Fig. 1D is a partially enlarged cross-sectional schematic diagram of the corrugated section in Fig. 1B of the present invention.

Fig. 2 is a schematic diagram of the implementation of the flexible heat dissipation device of the first embodiment of the present invention in an electronic device.

Fig. 3 is a three-dimensional assembly schematic diagram of a possible embodiment of the first embodiment of the present invention.

The above-mentioned purpose of the present invention and its structural and functional characteristics will be described based on the preferred embodiments of the accompanying drawings.

The present invention provides a flexible heat sink, please refer to Figures 1A to 3, the flexible heat sink 1 can be a loop heat pipe (or loop heat pipe; LHP) or a two-phase thermosiphon system (LTS) , the flexible cooling device 1 includes an evaporator 11, a steam pipe 12, a condenser 13, at least one corrugated section 16 and a liquid pipe 14, the evaporator 11 is connected with an electronic device (such as a server, a computer A circuit board 4 (such as a motherboard) in a circuit board 4 (such as a motherboard) has a heating element 42 (such as a central processing unit or a graphics processor) that is closely attached to each other, and the circuit board 4 further includes a plurality of electronic components 41 with different heights (such as capacitors, resistors, inductors or transistors) are arranged around the heating element 42 . The evaporator 11 is provided with a shell 111, at least one vapor chamber 113, a liquid inlet 115 and a vapor outlet 116, the shell 111 is made of metal (such as stainless steel, titanium, aluminum, copper or other metals) , and the inner wall of the housing 111 defines the at least one vapor chamber 113, the vapor chamber 113 contains at least one capillary structure 114 and a working fluid, the capillary structure 114 is a porous structure, which can be sintered powder , fine grooves, braided meshes, fibers or braids, or a composite capillary structure of any combination of the above, and the capillary structure 114 is described as a braided mesh in this embodiment, but is not limited thereto. Should The working fluid is, for example, pure water, methanol, distilled water or a mixture thereof, and the gas-liquid phase change mechanism of the working fluid is used to achieve heat transfer.

The liquid inlet 115 and the steam outlet 116 are respectively opened on the same side of the housing 111 in this implementation, and the liquid inlet 115 is located above the steam outlet 116, but it is not limited thereto. When the present invention is actually implemented , the liquid inlet 115 and the vapor outlet 116 can also be respectively disposed on opposite sides of the housing 111 . And the liquid inlet 115 and the steam outlet 116 are respectively communicated with the steam chamber 113, and a steam channel 112 is defined between the steam chamber 113 in the housing 111 and the corresponding steam outlet 116, and the steam channel 112 is connected with the steam The outlet 116 is connected to one end of the steam pipe 12 , so that the steam generated after the working fluid evaporates enters the steam pipe 12 from the steam channel 112 through the steam outlet 116 .

The steam pipe 12 and the liquid pipe 14 are made of metal material (such as stainless steel, titanium, aluminum, copper or other metals), and one end of the steam pipe 12 is connected to the steam outlet 116 of the housing 111, so that the steam One end of the pipe 12 communicates with the steam outlet 116 and the steam chamber 113, and the other end of the steam pipe 12 communicates with the condenser 13, and the condenser 13 is connected to a component (such as a fan frame or a heat dissipation fixed platform) in the electronic device. Connected to each other, the condenser 13 (which can be a cold row or a water row) is shown in this embodiment to have a vapor inlet 131, a liquid outlet 132, a vapor-liquid mixing channel 133 and a plurality of cooling fins 134, the vapor-liquid mixing The channel 133 extends from the steam inlet 131 to the upper liquid outlet 132 and connects with the liquid outlet 132. The plurality of cooling fins 134 are arranged on the top outer surface of the condenser 13 at intervals. The other end is connected to the steam inlet 131 and communicated. And one end and the other end of the liquid pipe 14 are respectively connected to the liquid outlet 132 and the liquid inlet 115 and communicated, so that the two ends of the liquid pipe 14 are connected to the evaporator 11 and the condenser 13 respectively, so that the evaporator 11. The steam pipe 12, the condenser 13 and the liquid pipe 14 form a circuit in which the working fluid flows. Therefore, when the evaporator 11 absorbs the heat on the heating element 42, the working fluid in the evaporator 11 is heated and evaporated to generate steam, and then passes through the pressure The force difference pushes the vapor working fluid in the vapor passage 112 to flow through the vapor outlet 116 through the vapor pipe 12, through the vapor inlet 131 to the vapor-liquid mixing passage 133 of the condenser 13, and through the condenser 13 and the plurality of The cooling fins 134 absorb the heat of the steam working fluid and condense it into a liquid working fluid, so that the liquid working fluid flows back through the liquid outlet 132 through the smooth inner surface 145 in the liquid pipe 14 and enters into the liquid inlet 115. The next cycle is performed in the vapor chamber 113 of the evaporator 11 . Wherein the steam pipe 12 and the liquid pipe 14 are respectively connected to the evaporator 11 and the condenser 13 by welding, scarfing or bonding.

At least one corrugated section 16 is arranged on either or both of the steam pipe 12 and the liquid pipe 14. In this embodiment, the corrugated section 16 is selected to be respectively arranged on the steam pipe 12 and the liquid pipe 14. The two ends of the section 16 are respectively connected with a straight section 15, the corrugated section 16 has a plurality of corrugations 161, the plurality of corrugations 161 can be arranged at intervals or continuously, and the plurality of corrugations 161 are alternately presented as a plurality of concavo-convex or a plurality of crests and troughs. structure, and because the corrugated section 16 itself has the functions of being bendable, oppositely concave (in a U shape), good stretching elasticity and shock-absorbing. In a feasible embodiment, the corrugated section 16 can be disposed on the steam pipe 12 or the liquid pipe 14 .

In this embodiment, at least one of the inner surface of the steam pipe 12 and the liquid pipe 14 may have a smooth inner surface, or a capillary structure provided on the inner surface of the pipe diameter.

In addition, one or more of the height X, width Y, and pitch 181 of the plurality of corrugations 161 are the same or different, and the pitches 181 of the plurality of corrugations 161 can be equidistant or non-equidistant. Each corrugation 161 has a corrugation top 1611 and a corrugation bottom 1612, and the corrugation bottom 1612 is located adjacent to an outer surface 124, 144 of the vapor tube 12 and liquid tube 14 (i.e., on the same surface as the outer surface 124, 144). horizontal or higher/lower than the outer surface 124,144), the corrugated tip 1611 protrudes from the vapor tube 12 and the liquid tube 14 Respective outer surfaces 124,144. And the height X of the corrugation 161 is defined between the corrugation top 1611 and the corrugation bottom 1612 .

Referring to each figure, the height X of the complex number of corrugations 161 is the same or different from each other, such as the height X of the plurality of corrugations 161 gradually becomes lower from the two sides of the corrugated section 161 to the middle, that is, in the middle of the corrugated section 16 The height of the corrugations 161 is relatively short, and the height X of the corrugations 161 on both sides of the corrugated section 16 gradually becomes higher. Since the corrugation 161 located in the middle of the corrugated section 16 is shorter than the height X of the corrugations 161 on both sides of the corrugated section 16, the complex corrugations 161 on the inner side of the corrugated section 16 will not interfere, so that bending at any angle or direction can be achieved (bending) or half-folding effect and improving the problem of limited bending angle, and can also be used with various circuit boards 4 and electronic components 41 with different height drops on the circuit board 4 .

In a feasible embodiment, referring to Fig. 3, supplemented by referring to Fig. 1C and 1D, it is mainly to change the liquid pipe 14 and vapor pipe 12 of the above embodiment into a single circuit pipe, and the two ends of the pipe are connected to the evaporator 11. The liquid inlet 115 and the steam outlet 116 are referred to as the vapor-liquid return pipe 2 for the convenience of description below, and the vapor-liquid return pipe 2 is provided with a vapor section 21 and a liquid section 22, and one end of the vapor section 21 and the liquid section 22 The steam outlet 116 is connected with the liquid inlet 115 and the steam chamber 113 respectively, and the other end of the steam section 21 is integrally extended outwards and connected to the other end of the liquid section 22 to form a condensation section 23, the condensation section 23 A condensing element 3 (such as a plurality of heat dissipation fins) is arranged on the outside, and at least one corrugated section 16 is arranged on either or both of the vapor section 21 and the liquid section 22. The corrugated section 16 in this embodiment represents two corrugated sections. Each section 16 has a plurality of intervals (or continuous) corrugations 161 arranged in the vapor section 21 and the liquid section 22 respectively. Those who are not the same) are the same as the aforementioned corrugated section 16 and will not be described again.

In addition, it should be noted that the plurality of corrugations 161 of the aforementioned corrugated section 16 are annular corrugations, and the corrugations 161 surround the pipe body of the steam pipe 12 and the liquid pipe 14 in a closed ring shape. In another implementation, the plurality of corrugations 161 are helical corrugations, that is, the corrugations are arranged in a helical shape to surround the pipe body of the steam pipe 12 and the liquid pipe 14 .

Referring to the figures, when the flexible heat dissipation device 1 is assembled on the electronic device, the evaporator 11 is pasted behind the heating element 42, and the corrugated section 16 of one of the steam pipe 12 and the liquid pipe 14 can pass through For any angle or direction bending (such as up, down, left, right bending) deformation adjustment, the complex corrugated 161 has a better stretching elasticity so that it has a stretching length to bypass the higher electrons around the heating element 42 The element 41 can also absorb the pulling of the evaporator 11 and the condenser 13 by the bridging force generated by the pipelines of the vapor pipe 12 and the liquid pipe 14 respectively through the corrugated section 16 .

1: Flexible cooling device

11: Evaporator

111: shell

12: Steam pipe

15: straight section

13: Condenser

134: cooling fins

14: Liquid pipe

16: corrugated section

161: Ripple

Claims (7)

A flexible heat dissipation device, comprising: a condenser; an evaporator having at least one vapor chamber, a liquid inlet and a vapor outlet, the vapor chamber accommodates a capillary structure and a working fluid, the liquid inlet and The steam outlet is connected to the steam chamber respectively; a steam pipe, one end of which is connected to the steam outlet, and the other end of the steam pipe is connected to the condenser; a liquid pipe, whose two ends are respectively connected to the evaporator and the condenser, so that The evaporator, the steam pipe, the condenser and the liquid pipe form a circuit of the working fluid; and at least one corrugated section is arranged on either or both of the vapor pipe and the liquid pipe, and the corrugated section has a plurality of corrugations, One or more of the height, width and spacing of the plurality of corrugations are different from each other, so that the corrugations on the curved inner side of the corrugated section will not interfere, and the effect of bending or half-folding at any angle or direction can be achieved and the bending can be improved. Angle limitation problem. The flexible heat dissipation device as described in item 1 of the scope of the patent application, wherein each of the corrugations has a corrugated top and a corrugated bottom, and the corrugated bottom is located on an outer surface of the vapor tube and the liquid tube respectively, the corrugations The corrugated top protrudes from the outer surfaces of the steam pipe and the liquid pipe respectively. In the flexible heat dissipation device described in item 2 of the scope of the patent application, the height of each corrugation is defined between the top end of the corrugation and the bottom end of the corrugation. The flexible heat dissipation device as described in item 1 of the scope of the patent application, wherein the liquid pipe is provided with a capillary structure of the pipe body, and the capillary structure of the pipe body is arranged on the inner surface of the liquid pipe. The flexible heat dissipation device described in claim 1 of the patent application, wherein the plurality of corrugations are annular corrugations or spiral corrugations. The flexible heat dissipation device described in claim 1 of the patent application, wherein the height of the plurality of corrugations gradually decreases from both sides to the middle of the corrugated section. The flexible heat dissipation device described in claim 1 of the patent application, wherein the capillary structure is a composite capillary structure of sintered powder, fine grooves, woven mesh, fibers or any combination of the above.

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