TW202420923A - Heat dissipation system of electronic device - Google Patents

Abstract

A heat dissipation system of an electronic device is provided, including a heat transfer element and a heat dissipation module. The heat transfer element is configured to be in thermal contact with a heating element. The heat dissipation module includes a case, a liquid pipe, and a heat dissipation fin. The case is connected with the heat transfer element, and an accommodation space is formed therebetween. An inlet and an outlet are formed on the sidewall of the case and communicate with the accommodation space. The liquid pipe has opposite first and second ends, the first end is connected to the inlet, and the second end is connected to the outlet. The heat dissipation fin is in thermal contact with the liquid pipe. A liquid is filled in the accommodation space and the liquid pipe. After absorbing heat from the heat transfer element, part of the liquid in the accommodation space boils and turns into air bubbles. The air bubbles flow into the liquid pipe through the outlet and transfer heat to the heat dissipation fin, then release the heat and return to the liquid, and then flow back to the accommodation space through the inlet.

Description

Heat dissipation system for electronic devices

The present invention relates to a heat dissipation system, and in particular to a heat dissipation system for an electronic device, including a thin two-phase flow heat dissipation module.

The heat dissipation modules currently used in electronic devices such as laptops mainly include heat pipes, heat sink fins, and fans. When the laptop is running, the heat generating components (such as the central processing unit) in the case will generate heat. At this time, the heat pipe can transfer the heat from the heat generating components to the heat sink fins. Then, through the operation of the fan, air is sucked into the case through the air inlet on the case, and then air flow is generated to blow toward the heat sink fins to exchange heat, and finally discharged from the air outlet on the case to the outside of the case to eliminate waste heat.

Although the above-mentioned one-phase flow heat dissipation module using air flow to dissipate heat is generally sufficient to meet its intended purpose, it is still not satisfactory in all aspects. For example, as the design trend of electronic devices (such as laptops or tablets) gradually moves towards thinness and lightness, the heat dissipation fan is also required to be thinner under the condition of limited internal space, which leads to the weakening of the heat dissipation airflow generated by the thin fan, affecting its heat dissipation efficiency.

It is known that a water-cooled system is a design that can effectively and quickly dissipate heat from electronic devices. Since the specific heat of water is greater than that of air, its heat absorption or heat dissipation capacity is also stronger. However, existing water-cooling systems are mostly composed of multiple components such as water pumps, water pipes, water cooling heads, water cooling radiators, and water tanks. The overall volume is quite large, so desktop computers are still the main application on the market. A few products designed for thin and light electronic devices such as laptops also need to be connected to a large base to accommodate the water-cooling system.

In view of the above-mentioned known problems, one purpose of the present invention is to provide a heat dissipation system for electronic devices, including a thin two-phase flow heat dissipation module, which can utilize the rapid heat absorption/heat dissipation characteristics of a water cooling system to improve the heat dissipation efficiency and can be applicable to thin electronic devices (such as laptops or tablet computers, etc.).

According to the above-mentioned purpose of the present invention, a heat dissipation system for an electronic device is provided, comprising a heat transfer element and a first heat dissipation module. The heat transfer element is configured to be in thermal contact with a heat generating element. The first heat dissipation module comprises a shell, a liquid pipe, and a first heat dissipation fin. The shell is connected to the heat transfer element, and a receiving space is formed between the shell and the heat transfer element, wherein an inlet and an outlet are formed on the side wall of the shell and communicate with the receiving space. The liquid pipe has a first end and a second end opposite to each other, wherein the first end is connected to the inlet, and the second end is connected to the outlet. The heat dissipation fin is in thermal contact with the liquid pipe. A liquid is filled in the containing space and the liquid pipe. After absorbing heat from the heat transfer element, part of the liquid in the containing space boils and turns into bubbles. The bubbles flow into the liquid pipe through the outlet and transfer the heat to the first heat sink fin. Then, they release heat and turn back into liquid, and then flow back to the containing space through the inlet.

In one embodiment, the liquid is a low boiling point liquid or a phase change liquid.

In one embodiment, one side of the shell is open and adjacent to the heat transfer element, wherein the first heat dissipation module further includes a bonding material formed at the interface between the shell and the heat transfer element for connecting the shell and the heat transfer element and sealing the containing space.

In one embodiment, the housing is transparent.

In one embodiment, the housing further has a plurality of locking structures extending from the side wall, and the first heat dissipation module further includes a plurality of locking members configured to pass through the locking structures and the heat transfer element to fix the housing on the heat transfer element.

In one embodiment, the locking member further passes through the heating element to fix the heat transfer element on the heating element.

In one embodiment, the liquid conduit is a metal pipe.

In one embodiment, the width of the liquid conduit increases gradually in a direction away from the outlet, and the width of the liquid conduit decreases gradually in a direction away from the inlet.

In one embodiment, the heat transfer element is a heat spreader or a metal block.

In one embodiment, the heat dissipation system of the electronic device further includes a second heat dissipation module. The second heat dissipation module includes a heat pipe, at least one second heat dissipation fin, and a fan, wherein the heat pipe is in thermal contact with the heat transfer element, the at least one second heat dissipation fin is in thermal contact with the heat pipe, and the fan is adjacent to the at least one second heat dissipation fin to generate a heat dissipation airflow blowing toward the at least one second heat dissipation fin.

Based on the above, the heat dissipation system of the electronic device of the present invention can rapidly cool down the heat generating element in the electronic device through the two-phase flow heat dissipation module (ie, the first heat dissipation module), thereby improving the performance.

In order to make the above and other purposes, features, and advantages of the present invention more clearly understood, preferred embodiments are specifically described below in detail with reference to the accompanying drawings.

The following describes the preferred embodiments of the present invention. The purpose of this description is to provide a general concept of the present invention and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the scope of the attached patent application.

In the following description, the so-called directions "upper", "lower" or other similar spatial terms are only with reference to the directions in the attached drawings. Therefore, the spatial terms used are only used for explanation and are not used to limit the present invention.

In the following text, "first", "second", etc. may be used to represent different elements, components or parts. These elements, components or parts are not limited by these terms. These terms are only used to distinguish these elements, components or parts. Therefore, the first element, component or part described below can also be replaced by the second element, component or part without departing from the teaching of the present invention. When a first element is mentioned on a second element, it may include the situation where the first element and the second element are directly in contact or separated by one or more other elements.

In addition, the following disclosure may repeatedly use the same reference symbols and/or labels in different examples. Such repetition is for the purpose of simplification and clarity, and is not intended to limit the specific relationship between the different embodiments and/or structures discussed. For the sake of simplicity and clarity, various features may be arbitrarily drawn in different proportions. Furthermore, the components not shown or described in the embodiments are in the form known to those skilled in the art.

FIG. 1 is a schematic diagram of a heat dissipation system of an electronic device according to an embodiment of the present invention. Referring to FIG. 1, the electronic device 10 of the present embodiment includes a heat generating element 100, a heat transfer element 200, at least one first heat dissipation module 300 (for example, two first heat dissipation modules 300a and 300b), and a second heat dissipation module 400. In different embodiments, some additional components or features may be added to the electronic device 10, and/or some features described below may be replaced or changed in other embodiments. The electronic device 10 is, for example, a thin electronic device such as a laptop or a tablet computer, but the present invention is not limited thereto. For the sake of simplicity and clarity, the housing, keyboard, screen, etc. of the electronic device 10 or other internal components that are not related to the present invention are not shown in the figure.

In this embodiment, the heat generating element 100 is a motherboard on which electronic components (not shown) that are prone to generate heat during operation, such as a central processing unit, are mounted. Therefore, a heat dissipation system as described below is required to help remove the heat from the heat generating element 100 to avoid affecting its performance.

The heat transfer element 200 is disposed on one side (e.g., on the top) of the heating element 100 and is in thermal contact with the heating element 100. The heat on the heating element 100 is transferred to the heat transfer element 200 by heat conduction. As shown in FIG. 1, the heat transfer element 200 is fixed on the heating element 100 by passing through the screw holes on the heat transfer element 200 and the heating element 100 by several fasteners T (e.g., screws and other fastening elements) at the same time. Although not shown, a heat transfer paste can be applied on the interface between the heat transfer element 200 and the heating element 100 (e.g., the electronic element on the top that is easy to generate heat) to assist heat conduction. In this embodiment, the heat transfer element 200 is a vapor chamber or a metal block (such as a copper block) to evenly distribute heat throughout the heat transfer element 200. However, the present invention is not limited thereto and other suitable heat transfer elements may also be used.

Each first heat dissipation module 300 includes at least one heat pipe 301, at least one heat dissipation fin 302 (sometimes also called a heat dissipation fin array), and a fan 303, and is thermally coupled to the heat transfer element 200 and/or the heat generating element 100. For example, in the embodiment of FIG. 1, there are two first heat dissipation modules 300 (300a and 300b), wherein the first heat dissipation module 300a includes a heat pipe 301a in thermal contact with the heat transfer element 200, two heat dissipation fins 302a and 302b in thermal contact with the heat pipe 301a (spaced from each other and extending in two orthogonal directions (e.g., the X and Y directions in the figure)), and a fan 303 disposed adjacent to the two heat dissipation fins 302a and 302b. The first heat dissipation module 300b includes two heat pipes 301b and 301c in thermal contact with the heat transfer element 200 and the heat generating element 100 respectively, two heat dissipation fins 302c and 302d in thermal contact with the two heat pipes 301b and 301c respectively (separated from each other and extending in two orthogonal directions (e.g., X and Y directions in the figure)), and a fan 303b disposed adjacent to the two heat dissipation fins 302c and 302d. Each of the fans 303a and 303b is, for example, a centrifugal fan that can generate a sideways air flow.

With the above configuration, the heat from the heat transfer element 200 and/or the heat generating element 100 is transferred to the heat sink fins 302a-302d through the heat pipes 301a-303c, and the fans 303a-303b can generate air flow to blow toward the heat sink fins 302a-302d (as shown by the solid arrows in the figure) to exchange heat, and finally the air is discharged from the air outlet on the electronic device housing (not shown) to the outside of the housing to remove waste heat. The specific structure and operation mechanism of the first heat dissipation module 300 are well known to those skilled in the art, so no further description is given here. It should be understood that the configuration of the first heat dissipation module 300 (300a and 300b) is provided for illustrative purposes only and is not intended to limit the present invention and should not be interpreted as limiting the present invention. Once prompted by the present disclosure, many alternatives and modifications are obvious to those skilled in the art. For example, in other embodiments, there may be only one of the first heat dissipation modules 300a and 300b.

As mentioned above, although a one phase flow heat dissipation module (e.g., the first heat dissipation module 300) is usually sufficient to meet its intended purpose, in order to be applied to thin electronic devices, its fan also needs to be thinned (i.e., the thickness in the Z direction in the figure is reduced), which causes the heat dissipation airflow generated by the fan to be weakened, thereby affecting its heat dissipation efficiency. Therefore, the heat dissipation system in this embodiment also includes a second heat dissipation module 400, which can be combined with the above heat dissipation system to provide another additional heat exchange (heat dissipation) path without affecting the heat dissipation performance of the original first heat dissipation module 300 to improve the heat dissipation efficiency.

In this embodiment, the second heat dissipation module 400 is a thin two-phase flow heat dissipation module that can utilize the rapid heat absorption/dissipation characteristics of the water cooling system to improve heat dissipation efficiency and is also applicable to thin electronic devices. The following description introduces the design and working principle of the second heat dissipation module 400 with reference to Figures 2 to 4. Figures 2 and 3 are respectively a three-dimensional diagram and a partial exploded diagram of the heat dissipation system in Figure 1, and Figure 4 is a schematic diagram of the working principle of the second heat dissipation module 400 (two-phase flow heat dissipation module) in the heat dissipation system. The features of the heat dissipation system described in Figure 1 (i.e., the heat transfer element 200 and the first heat dissipation module 300) will not be repeated here. As shown in FIGS. 2 to 4 , the second heat dissipation module 400 includes a housing 401 , a liquid pipe 402 , and a heat dissipation fin 403 (sometimes also referred to as a heat dissipation fin array).

The shell 401 is disposed on and connected to the heat transfer element 200. In this embodiment, the shell 401 is a hollow shell, and its bottom side (e.g., the bottom side in the figure) is open. When disposed on the heat transfer element 200, the bottom side of the shell 401 is adjacent to the upper surface 201 of the heat transfer element 200, thereby forming a containing space S between the shell 401 and the heat transfer element 200. More specifically, the containing space S is formed by the upper surface 201 of the heat transfer element 200, the top wall 4011 of the shell 401, and the side wall 4012 of the shell 401, as shown in FIG. 4.

In this embodiment, a bonding material (not shown separately for simplicity) may be provided or formed at the interface between the housing 401 and the heat transfer element 200 (e.g., between the bottom edge of the side wall 4012 of the housing 401 and the upper surface 201 of the adjacent heat transfer element 200) to connect the housing 401 and the heat transfer element 200 and seal the containing space S. The bonding material may be thermal conductive paste, welding material or other optional adhesive material. In addition, the housing 401 has a plurality of locking structures 4013 extending transversely from the side wall 4012, and screw holes are formed thereon (as shown in FIG. 3). For example, a plurality of locking pieces T (such as locking elements such as screws) pass through the locking structures 4013 and the screw holes on the heat transfer element 200 at the same time, so that the housing 401 can be tightly fixed on the heat transfer element 200. In this embodiment, part of the screws and screw holes used to lock the heat transfer element 200 to the heating element 100 are directly used to lock the housing 401 (as shown in FIGS. 2 to 4), thereby improving commonality.

It should be understood that the shape of the housing 401 shown in Figures 2 to 4 is designed only to fit the space on the heat transfer element 200 not occupied by the first heat dissipation module 300. Therefore, the present invention is not limited to this and other suitable shapes may be used. In addition, to meet the goal of thinness, the thickness of the housing 401 (for example, the distance from the top of the top wall 4011 of the housing 401 to the bottom edge of the side wall 4012, along the Z direction in the figure) may be close to the thickness of the heat pipe of the first heat dissipation module 300, but the present invention is not limited to this and may be adjusted according to actual needs.

In this embodiment, the housing 401 may be made of transparent materials such as plastic, glass or acrylic, so that the two-phase flow (i.e., heat exchange) in the containing space S can be directly observed from the outside with the naked eye (to be further described later). However, the housing 401 may also be non-transparent and/or made of other optional materials.

In this embodiment, the side wall 4012 of the housing 401 is provided with an inlet 4014 and an outlet 4015, which are respectively connected to the containing space S, as shown in FIG. 4. The liquid pipe 402 is a hollow pipe, and its two ends are open, one end is connected to the inlet 4014, and the other end is connected to the outlet 4015. Therefore, the containing space S and the inner channel of the liquid pipe 402 form a closed fluid loop. Although not separately shown, an insulating liquid may be filled in the containing space S and the liquid pipe 402. The liquid may be, for example, a low boiling point liquid or a phase change liquid (e.g., Novec electronic engineering fluid proposed by 3M for two-phase immersion cooling technology), which may boil into a gas when absorbing heat, and condense back into a liquid after releasing heat (i.e., a two-phase heat exchange phenomenon). In this embodiment, the liquid pipe 402 is a metal pipe (e.g., a copper pipe) with high thermal conductivity. The heat sink fin 403 is in thermal contact with the liquid pipe 402, for example, through thermal conductive paste or direct contact.

By configuring the second heat dissipation module 400, part of the liquid (low boiling point liquid) in the storage space S can absorb heat from the heat transfer element 200, and after absorbing heat, it boils and becomes bubbles (bodies). As the number of bubbles gradually increases, the pressure generated can push the bubbles through the outlet 4015 of the shell 401 and flow into the liquid pipe 402 (the thick arrow in Figure 4 indicates the flow direction of the bubbles). Afterwards, the bubbles in the liquid pipe 402 exchange heat with the heat dissipation fin 403 (i.e., transfer heat to the heat dissipation fin 403), then release heat/condense and become liquid again, and then flow back to the storage space S through the inlet 4014 of the shell 401 (the thin arrow in Figure 4 indicates the flow direction of the condensed liquid). In this embodiment, the heat of the heat sink fin 403 can be gradually dissipated into the air over time. In other embodiments, a fan can be further provided near the heat sink fin 403 to generate forced convection through the fan to quickly transfer the heat of the heat sink fin 403 into the air.

Therefore, the second heat dissipation module 400 can provide another additional heat exchange (heat dissipation) path, and the two-phase heat exchange has better heat absorption/heat dissipation capacity than the single-phase heat exchange (because the specific heat of water is greater than the specific heat of air), thereby greatly improving the heat dissipation efficiency of the overall heat dissipation system.

It should be understood that, although the above-mentioned embodiment utilizes a two-phase flow heat dissipation module (the second heat dissipation module 400) to assist in improving the poor heat dissipation efficiency of the original single-phase flow heat dissipation module (the first heat dissipation module 300), in other embodiments, the heat dissipation system may also omit the single-phase flow heat dissipation module and only include a two-phase flow heat dissipation module.

Many variations and/or modifications can also be made to the two-phase flow heat dissipation module embodiment of the present invention. For example, in the embodiment shown in Figure 5, the overall liquid conduit 402 can have a uniform width W. In the embodiment shown in FIG. 6 , the portions of the liquid conduit 402 near the inlet 4014 and the outlet 4015 of the shell 401 may have variable (different) widths. More specifically, the width of the portion of the liquid conduit 402 near the outlet 4015 gradually increases in the direction D1 away from the outlet 4015, while the width of the portion of the liquid conduit 402 near the inlet 4014 gradually decreases in the direction away from the inlet 4014. Such a structural design can further promote the flow of fluid (liquid and bubbles) in the two-phase flow heat dissipation module, thereby improving the heat exchange/heat dissipation efficiency.

In summary, the present invention provides an electronic device heat dissipation system including a two-phase heat dissipation module. The two-phase heat dissipation module can be combined with the existing single-phase heat dissipation module to provide another additional heat exchange (heat dissipation) path, or can be used as the main heat dissipation path of the heat dissipation system. Since the heat absorption/heat dissipation capacity of the two-phase heat dissipation module is better than that of the existing single-phase heat dissipation module (because it has the characteristics of rapid heat absorption/heat dissipation of the water cooling system), the heat dissipation efficiency of the heat dissipation system can be greatly improved, thereby enhancing performance. In addition, the two-phase heat dissipation module also has the advantage of being thin, which improves its commonality and can be applied to today's thin electronic devices.

The foregoing text summarizes the features of many embodiments so that those skilled in the art can better understand the present disclosure from all aspects. Those skilled in the art should understand and can easily design or modify other processes and structures based on the present disclosure to achieve the same purpose and/or achieve the same advantages as the embodiments introduced herein. Those skilled in the art should also understand that these equivalent structures do not deviate from the spirit and scope of the invention of the present disclosure. Various changes, substitutions or modifications may be made to the present disclosure without departing from the spirit and scope of the invention of the present disclosure.

10: electronic device 100: heating element 200: heat transfer element 201: upper surface 300, 300a, 300b: first heat dissipation module 301a, 301b, 301c: heat pipe 302a, 302b, 302c, 302d: heat dissipation fins 303a, 303b: fan 400: second heat dissipation module 401: housing 402: liquid pipe 403: heat dissipation fins 4011: top wall 4012: side wall 4013: locking structure 4014: inlet 4015: outlet S: storage space T: locking device W: width

FIG. 1 is a schematic diagram of a heat dissipation system of an electronic device according to an embodiment of the present invention, showing that the heat dissipation system is arranged on a heat generating element of the electronic device. FIG. 2 is a three-dimensional diagram of the heat dissipation system in FIG. 1. FIG. 3 is a partial exploded diagram of the heat dissipation system in FIG. 2. FIG. 4 is a schematic diagram of the working principle of a two-phase flow heat dissipation module in the heat dissipation system. FIG. 5 is a schematic diagram showing that a liquid pipeline according to an embodiment of the present invention has a uniform width. FIG. 6 is a schematic diagram showing that a liquid pipeline according to an embodiment of the present invention has a variable width at the inlet and outlet near the housing.

200: Heat transfer element

201: Upper surface

400: Second heat dissipation module

401: Shell

402:Liquid pipeline

403: Heat sink fins

4011: Top wall

4012: Side wall

4013: Locking structure

4014:Entrance

4015:Export

S: Accommodation space

T: Lock firmware

Claims (10)

A heat dissipation system for an electronic device comprises: A heat transfer element configured to be in thermal contact with a heating element; and A first heat dissipation module comprising: A housing connected to the heat transfer element and forming a receiving space between the housing and the heat transfer element, wherein an inlet and an outlet are formed on a side wall of the housing and communicate with the receiving space; A liquid pipeline having a first end and a second end opposite to each other, wherein the first end is connected to the inlet and the second end is connected to the outlet; and A first heat dissipation fin in thermal contact with the liquid pipeline; A liquid is filled in the containing space and the liquid pipe. After absorbing heat from the heat transfer element, part of the liquid in the containing space boils and turns into bubbles. The bubbles flow into the liquid pipe through the outlet and transfer heat to the first heat sink fin. Then they release heat and turn back into the liquid, and then flow back to the containing space through the inlet. A heat dissipation system for an electronic device as claimed in claim 1, wherein the liquid is a low boiling point liquid or a phase change liquid. A heat dissipation system for an electronic device as claimed in claim 1, wherein one side of the housing is open and adjacent to the heat transfer element; and wherein the first heat dissipation module further comprises a bonding material formed at the interface between the housing and the heat transfer element for connecting the housing and the heat transfer element and sealing the containing space. A heat dissipation system for an electronic device as claimed in claim 1, wherein the housing is transparent. In the heat dissipation system of claim 1, the housing further comprises a plurality of locking structures extending from the side wall, and the first heat dissipation module further comprises a plurality of locking members configured to pass through the locking structures and the heat transfer element to fix the housing on the heat transfer element. In the heat dissipation system of claim 5, the locking members further pass through the heat generating element to fix the heat transfer element above the heat generating element. A heat dissipation system for an electronic device as claimed in claim 1, wherein the liquid pipe is a metal pipe. A heat dissipation system for an electronic device as claimed in claim 1, wherein the width of the liquid conduit gradually increases in a direction away from the outlet, and the width of the liquid conduit gradually decreases in a direction away from the inlet. In the heat dissipation system of the electronic device of claim 1, the heat transfer element is a heat spreader or a metal block. The heat dissipation system of the electronic device of any one of claims 1 to 9 further includes a second heat dissipation module, including: a heat pipe in thermal contact with the heat transfer element; at least one second heat dissipation fin in thermal contact with the heat pipe; and a fan adjacent to the at least one second heat dissipation fin for generating a heat dissipation airflow toward the at least one second heat dissipation fin.

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