CN117795281A

CN117795281A - Heat radiating element and cooling system for notebook computer and method for manufacturing heat radiating element

Info

Publication number: CN117795281A
Application number: CN202180100666.2A
Authority: CN
Inventors: 迪迷特·莱尼达维奇·库什; 亚乌赫尼·乌拉吉米拉维奇·阿皮马克; 吴会鹏; 杨果
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-07-22
Filing date: 2021-07-22
Publication date: 2024-03-29
Also published as: WO2023000072A1

Abstract

A heat sink member (102) for a notebook computer liquid cooling system is provided. The heat dissipation element includes: an inlet (104) arranged in a lower corner (106) of a screen portion (108) of the notebook computer and for receiving a heating fluid; an outlet (112) arranged in an opposite lower corner (114) of the screen portion for returning cooling fluid. The heat dissipation element includes: a rising portion (116) arranged to carry the fluid from the inlet to a top corner (118) of the screen portion; and a descending portion (120) arranged to carry the fluid from the ascending portion to the outlet. The heat sink element improves thermal performance in that the fluid used to absorb the heat of the notebook computer is cooled to ambient temperature levels. As a result, the heat dissipation element improves cooling efficiency. Furthermore, the heat dissipating element provides a uniform heat distribution.

Description

Heat radiating element and cooling system for notebook computer and method for manufacturing heat radiating element

Technical Field

The present invention relates generally to the field of cooling systems, and more particularly, to a heat dissipating member for a cooling system of a notebook computer, a cooling system for a notebook computer, and a method of manufacturing a heat dissipating member for a cooling system of a notebook computer.

Background

As technology advances, computing devices such as notebook computers have become more advanced in terms of functionality and output generation. The current notebook power is increased, so that the amount of heat generated by the central processing unit (central processing unit, CPU) and/or the graphics processing unit (graphics processing unit, GPU) in the notebook (especially in the gaming notebook) is increased. However, there are limitations to the space of a notebook computer or tablet computing device, and therefore, it is a challenging task to produce an efficient and user-friendly (i.e., low noise, low weight, no active maintenance) cooling system for a notebook computer (or other portable small computing device, such as a tablet computing device).

Traditionally, in notebook liquid cooling systems, the heat generated (from the CPU and/or GPU) is dissipated from the desktop back cover surface of the notebook. Furthermore, there is a closed loop filled with a liquid that works as a carrier. The loop consists of a cold plate located at the keyboard portion of the notebook computer. The cold plate is connected to the heat generating unit (CPU and/or GPU) and absorbs heat by means of a cooling liquid inside the cold plate. The heated liquid is pumped using a micropump onto the other (i.e., second) cold plate located in the desktop portion of the notebook computer. The second cold plate is connected to the metal back cover of the notebook computer. Thus, the second cold plate dissipates heat into the environment, thereby cooling the liquid passing through the heat dissipating cold plate in the tabletop section. Thus, the liquid returns to the cooled keyboard section and is ready to again absorb heat from the heat source, thereby closing the loop of the cooling system.

However, because of the limited space available in the tabletop section for the heat sink cold plate (e.g., a gap of only one hundred microns), there are problems associated with the known liquid cooling schemes described above. Within a given limit, a balance needs to be struck between the pressure loss and the thermal efficiency of the heat-dissipating cold plate. Thermal efficiency refers to the temperature distribution along the table top back cover being as uniform as possible within a given boundary. In other words, the hot liquid entering the heat dissipating cold plate must be able to cool to the lowest possible temperature, i.e. the temperature of the ambient air, before moving back to the cold plate within the keyboard portion of the notebook computer. Otherwise, when returning to the heat absorbing cold plate, the relatively high temperature (i.e., above ambient temperature level) coolant is heated as it receives excess heat from the CPU and/or GPU and enters the heat dissipating cold plate in the tabletop section at an elevated temperature compared to the previous cycle. Thus, the steady-state temperature of such cooling systems is gradually set at a level higher than that which might be set at the time of high thermal efficiency design.

Furthermore, in some systems, the table top back cover may be made of aluminum, which may have a thermal conductivity level of, for example, 200W/mK. In such a system, the table top rear cover may effectively be part of a liquid cooling system. However, in order to reduce the weight of the notebook computer, the weight of the cooling system may be reduced. Thus, a lower density material, such as an Al-Mg alloy, is used. However, the thermal conductivity of the alloy is reduced to below 100W/mK. Further, such a plate of al—mg alloy is thin (i.e., less than 1mm thick), and thus the heat diffusion capability is reduced compared to the case of a rear cover made of aluminum.

Some conventional techniques use a U-shaped heat sink or serpentine heat sink. U-shaped or serpentine designs can lead to increased pressure losses in the case of narrow channels and multi-turn flows. In some conventional techniques, the heat sink cold plate is designed by enlarging the contact area between the liquid (cold plate wall) and the metal rear cover of the table top. However, in some cases, there may be regions of low (even near zero) liquid velocity, resulting in limited heat transfer in the tip region.

Furthermore, in some cases, a radiator that is not mechanically designed may lack mechanical strength against changes in internal pressure and may expand or contract depending on the relationship of the internal pressure of the loop to the ambient pressure level. This further leads to thermal contact losses between the cold plate and the metal back cover of the table top and reduces the overall thermal efficiency of the entire cooling loop. Therefore, there are technical problems in that the thermal efficiency is reduced and the loss is increased in the conventional liquid cooling system.

Thus, in light of the above discussion, there is a need to overcome the above-described drawbacks associated with conventional cooling of notebook computers.

Disclosure of Invention

The present invention seeks to provide a heat dissipating element for a cooling system for a notebook computer, and a method of manufacturing a heat dissipating element for a cooling system for a notebook computer. The present invention seeks to provide a solution to the existing problems of reduced thermal efficiency and increased pressure loss in conventional cooling systems. It is an object of the present invention to provide a solution which at least partly overcomes the problems encountered in the prior art and to provide an improved cooling system which has improved thermal efficiency and mechanical strength and provides a controlled pressure loss compared to conventional cooling systems.

The object of the invention is achieved by the solution provided in the attached independent claims. Advantageous implementations of the invention are further defined in the dependent claims.

In one aspect, the present invention provides a heat dissipating component for a notebook computer cooling system, comprising: an inlet disposed in a lower corner of a screen portion of the notebook computer and for receiving a heating fluid; an outlet arranged in the opposite lower corner of the screen portion to return cooling fluid; a rising portion arranged to carry the fluid from the inlet to a top corner of the screen portion; a descending portion arranged to carry the fluid from the ascending portion to the outlet.

The heat dissipating component of the present invention improves thermal performance in that the fluid used to absorb the heat of the notebook computer is cooled to ambient temperature levels. Thus, no fluid having a relatively high temperature (i.e., above ambient temperature level) is returned for heat absorption as compared to conventional heat dissipating elements. Thus, the heat dissipation element improves cooling performance and/or improves cooling efficiency. Advantageously, the heat dissipating element of the present invention provides a uniform heat distribution, i.e., the heat from the fluid spreads evenly throughout the screen portion.

In one implementation, the rising portion is arranged along a substantially diagonal path from the entrance to the opposite vertex angle of the screen portion.

By a substantially diagonal path, the heat of the fluid is partially dissipated by the screen. The screen portion is heated uniformly along a substantially diagonal path, i.e., uniformly spreading heat from the heating fluid.

In another implementation, the descending portion is arranged along a substantially vertical path from the ascending portion to the outlet.

Thus, the fluid flowing in the substantially vertical path is cooled to ambient temperature levels before it exits to absorb heat. Thus, thermal performance is improved.

In another implementation, the heat dissipation element is formed to cover less than 50% of a total area of the screen portion of the notebook computer.

Therefore, the weight and cost of the heat dissipating element are reduced as compared to conventional heat dissipating elements. Furthermore, the coverage of the heat dissipating element is less than 50% of the total area, so that the screen portion has a suitable heat dissipation, i.e. a heat dissipation with high thermal efficiency.

In another implementation, an area ratio between an area covered by the heat dissipating element and the total area of the screen portion is 1:4 or greater.

Therefore, weight and cost are reduced compared to conventional heat dissipating elements. Furthermore, a ratio of 1:4 can improve the accommodation of the heat dissipating element within the screen portion.

In another implementation, the area covered by the ascending portion and the area covered by the descending portion are substantially 1:1.

The ratio of the rising portion to the falling portion is 1:1, ensuring a non-constant volumetric flow of fluid into and out of the keyboard portion and from the keyboard portion to the screen portion. This ratio ensures that the volumetric flow rates in the ascending and descending sections are different, achieving the thermal benefit of different fluid velocities in the ascending and descending sections.

In another implementation, the heat dissipating element is formed such that the screen portion comprises an upper free triangle, which is not covered by the heat dissipating element, arranged in a top corner of the screen portion above the inlet.

By the upper free triangle, the weight of the heat dissipating element and the weight of the fluid are reduced.

In another implementation, the heat dissipating element is formed such that a lower free triangle of the screen portion is not covered by the heat dissipating element, arranged on a lower edge of the screen portion between the inlet and the outlet.

Advantageously, the two triangular portions are free to dissipate heat to the environment. Accordingly, the total weight of the heat dissipating element is reduced compared to conventionally designed heat dissipating units.

In another implementation, the heat dissipating element includes a flat sheet and a shaped sheet that form channels for the ascending portion and the descending portion.

Thus, heat in the fluid flowing through the channel is dissipated in the rising portion through the screen portion. In addition, the fluid flowing through the channels is further cooled in the descending portion.

In another implementation, one of the flat sheet and the shaped sheet is integrally formed with the cover of the screen portion.

Thus, one wall of the heat dissipating member is replaced by the cover such that the inner surface of the table top cover serves as the wall of the heat dissipating member and provides mechanical structural support for the heat dissipating member. Furthermore, the weight of the cooling system is saved as a whole.

In another implementation, the shaped sheet includes a plurality of posts formed within the channel for contacting the flat sheet and supporting the channel.

The plurality of posts provide mechanical strength to the channel. Advantageously, the mechanical strength ensures a stable thermal contact with the rear cover of the screen throughout the heat dissipating operation.

In another implementation, the shaped sheet is formed by an etching process or a stamping process.

The shaped sheets formed by the etching process have improved thermal efficiency because they are better able to transfer heat through the solids of their pillars. The etching process is replaced by a punching process to enable the weight of the heat dissipating element to be reduced.

In another implementation, the high thermal conductivity plate is arranged to cover the lower corner of the screen portion where the inlet is located.

Advantageously, the highly thermally conductive plate is capable of spreading heat along the liquid inlet region (the fluid having the highest temperature).

In another aspect, the present invention provides a cooling system for a notebook computer, comprising: a heat collecting element disposed in a keyboard portion of the notebook computer; the heat dissipation element of any one of the preceding claims, disposed in a screen portion of the notebook computer; a micropump for moving fluid from the heat collection element through the heat dissipation element and back to the heat collection element in a closed loop manner.

The cooling system of the present invention improves thermal performance in that the fluid used to absorb the heat of the notebook computer is cooled to ambient temperature. Thus, no fluid having a relatively high temperature (i.e., above ambient temperature level) is returned for heat absorption as compared to conventional liquid cooling systems. Thus, the cooling system provides improved cooling. Advantageously, the heat dissipating element of the present invention provides a uniform heat distribution, i.e., the heat from the fluid spreads evenly throughout the screen portion. Furthermore, the total weight of the heat dissipating element of the present invention is reduced compared to conventional heat dissipating elements of liquid cooling systems. In addition, the pressure loss is controlled and the mechanical strength is increased.

In another aspect, the present invention provides a notebook computer including a cooling system.

The notebook computer achieves all the advantages and effects of the cooling system of the present invention.

In another aspect, the present invention provides a method of manufacturing a heat dissipating component for a notebook computer cooling system, comprising: forming a rising portion to carry fluid from an inlet disposed in a lower corner of a screen portion of the notebook computer to opposite vertex corners of the screen portion; a descending portion is formed, the descending portion being arranged to carry the fluid from the ascending portion to an outlet arranged in an opposite lower corner of the screen portion.

This approach achieves all of the advantages and effects of the heat dissipating component of the present invention.

It should be appreciated that all of the above implementations may be combined. All steps performed by the various entities described in this application, as well as the functions described to be performed by the various entities, are intended to indicate that the respective entities are adapted to or for performing the respective steps and functions. Although in the following description of specific embodiments, a particular function or step performed by an external entity is not reflected in the description of a specific detailed element of the entity performing the particular step or function, it should be clear to a skilled person that the methods and functions may be implemented in corresponding hardware or software elements or any combination thereof. It will be appreciated that features of the invention are susceptible to being combined in various combinations without departing from the scope of the invention as defined by the accompanying claims.

Additional aspects, advantages, features and objects of the invention will become apparent from the accompanying drawings and detailed description of illustrative implementations which are explained in connection with the following appended claims.

Drawings

The foregoing summary, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings exemplary constructions of the invention. However, the invention is not limited to the specific methods and instrumentalities disclosed herein. Moreover, those skilled in the art will appreciate that the drawings are not drawn to scale. Wherever possible, like elements are designated by like numerals.

Embodiments of the invention will now be described, by way of example only, with reference to the following figures, in which:

FIG. 1A is a diagram of a heat dissipating component for a notebook computer liquid cooling system provided by an embodiment of the present invention;

FIG. 1B is a side view of a heat dissipating component for a notebook computer liquid cooling system provided by an embodiment of the invention;

FIG. 1C is a block diagram of a liquid cooling system for a notebook computer provided by an embodiment of the invention;

FIG. 2 is a diagram of a screen portion with a heat sink element for a notebook computer provided by an embodiment of the invention;

FIG. 3A is a diagram of a heat dissipating component provided by an embodiment of the present invention;

FIG. 3B is an illustration of a side view of a heat dissipating element in a screen portion of a notebook computer provided by an embodiment of the invention;

FIG. 3C is a cross-sectional view of a heat dissipating component provided by an embodiment of the present invention;

FIG. 4A is a graphical representation of the shape of a plurality of posts of a shaped sheet of a heat dissipating element provided by an embodiment of the present invention;

FIG. 4B is an illustration of a three-dimensional view of a shaped sheet including a post having a capsule shape provided by an embodiment of the present invention;

FIG. 4C is an illustration of a three-dimensional view of a formed sheet including posts having an elongated wall shape provided by an embodiment of the present invention;

FIG. 5A is a diagram of a formed sheet formed by an etching process provided by an embodiment of the present invention;

FIG. 5B is an illustration of a formed sheet formed by a stamping process provided by an embodiment of the present invention;

FIG. 6 is a diagram of a heat dissipating component having a high thermal conductivity plate provided by an embodiment of the present invention;

FIG. 7 is a flow chart of a method of manufacturing a heat dissipating component for a notebook computer liquid cooling system provided by an embodiment of the present invention.

In the drawings, the underlined numbers are used to denote items where the underlined numbers are located or items adjacent to the underlined numbers. The non-underlined numbers are associated with items identified by lines associating the non-underlined numbers with the items. When a number is not underlined and accompanies an associated arrow, the number without the underline is used to identify the general item to which the arrow points.

Detailed Description

The following detailed description illustrates embodiments of the invention and the manner in which the embodiments may be practiced. While a few modes of carrying out the invention have been disclosed, those skilled in the art will appreciate that there may be other embodiments for carrying out or practicing the invention.

Fig. 1A is a diagram of a heat dissipating component for a notebook computer liquid cooling system provided by an embodiment of the invention. Referring to fig. 1A, a diagram 100A of a heat dissipating element 102 is shown. The inlet 104, lower corner 106, screen portion 108 of the notebook computer, fluid 110, outlet 112, opposite lower corner 114, ascending portion 116, top corner 118, and descending portion 120 are shown.

In one aspect, the present invention provides a heat dissipating component 102 for a notebook computer liquid cooling system, comprising:

an inlet 104 disposed in a lower corner 106 of a screen portion 108 of the notebook computer and for receiving a heating fluid 110;

an outlet 112 disposed in an opposite lower corner 114 of the screen portion 108 to return the cooling fluid 110;

a rising portion 116 arranged to carry fluid 110 from inlet 104 to a top corner 118 of screen portion 108;

the descending portion 120 is arranged to carry the fluid 110 from the ascending portion 116 to the outlet 112.

The heat dissipation element 102 is used in a notebook computer liquid cooling system. In other words, the heat dissipation member 102 may be located inside the desktop rear cover of the notebook computer. The heat dissipating element 102 may also be referred to as a cold plate. The heat dissipating element 102 has a gap for liquid movement. A liquid (i.e., fluid) circulates in a loop to transfer heat from a central processing unit (central processing unit, CPU) to a desktop back cover where the heat dissipates into the environment. A notebook computer herein refers to any computing device having a screen and other components (e.g., keyboard portion, CPU, and/or GPU) that may be generating heat. Examples of a notebook computer may include, but are not limited to, a notebook computer, a personal computer, and the like.

The heat dissipating element 102 comprises an inlet 104, said inlet 104 being arranged in a lower corner 106 of a screen portion 108 of the notebook computer and being adapted to receive a heating fluid 110. In other words, the hot liquid (i.e., heating fluid 110) is pumped to the opposite (furthest) region of the tabletop surface. The inlet 104 is for receiving a heated fluid 110 from a keyboard portion of the notebook computer, wherein the generated heat is absorbed by the fluid 110. A heating fluid 110 is provided at the inlet 104 to enable heat dissipation in the fluid 110 through the screen portion 108.

The heat dissipating element 102 further comprises an outlet 112, said outlet 112 being arranged in an opposite lower corner 114 of the screen portion 108 for returning the cooling fluid 110. In other words, the heating fluid 110 flows downward under the force of gravity, and the heating fluid 110 is cooled to an ambient temperature level. Accordingly, the heat dissipation member 102 ensures that the heat dissipation capability of the rear cover is fully utilized. In addition, the outlet liquid line that returns the fluid 110 to the heating zone is not overheated. The outlet 112 is used to provide the cooling fluid 110 to the keyboard portion of the notebook computer such that the fluid 110 further absorbs heat.

The heat dissipating element 102 further comprises a rising portion 116 arranged to carry the fluid 110 from the inlet 104 to a top corner 118 of the screen portion 108. The rising portion 116 is arranged to carry the fluid 110 to enable heat dissipation in the fluid 110 through the screen portion 108 (i.e., the back cover) of the notebook computer. In addition, the more the surface of the rear cover is heated, the more efficient the heat dissipation. Due to the thermal conductivity of the metallic back cover, the back cover heats uniformly along the inlet 104, i.e., spreads the heat carried by the heating fluid 110. The heated back cover further dissipates heat into the environment.

The heat dissipating element 102 further comprises a descending portion 120 arranged to carry the fluid 110 from the ascending portion 116 to the outlet 112. The fluid 110 is cooled to an ambient temperature level before the fluid 110 flows out to the keyboard portion to avoid heating the fluid 110 back to the keyboard portion. Thus, the present invention provides for the design of the outlet 112 as an extended downward region, i.e., the drop down portion 120. Advantageously, the drop-down portion 120 allows the fluid 100 to flow downwardly with a large contact area with the back cover to enable the fluid 100 to cool to room temperature levels.

According to one embodiment, the heat sink 102 is formed to cover less than 50% of the total area of the screen portion 108 of the notebook computer. Accordingly, the weight and cost of the heat sink 102 is reduced as compared to conventional heat sink elements of liquid cooling systems. Further, the coverage of the heat dissipation element 102 is less than 50% of the total area, so that the screen portion 108 can properly dissipate heat.

According to one embodiment, the area ratio between the area covered by the heat dissipating element 102 and the total area of the screen portion 108 is 1:4 or greater. The notebook computer has limited space for accommodating the heat sink 102, so that the heat sink 102 covers an area to total area of the screen portion 108 ratio of 1:4 or more. Furthermore, this results in a weight and cost reduction compared to conventional heat dissipating elements of liquid cooling systems.

According to one embodiment, the inlet/outlet ratio between the area covered by the rising portion 116 and the area covered by the falling portion 120 is substantially 1:1. The 1:1 ratio of the ascending portion 116 and the descending portion 120 ensures a non-constant volumetric flow of the fluid 110 into and out of the keyboard portion and from the keyboard portion to the screen portion 108. This ratio ensures that the volumetric flow rates in the ascending and descending sections are different, achieving the thermal benefit of different fluid velocities in the ascending and descending sections.

According to one embodiment, the heat dissipating element 102 is formed to have a thickness of less than 400 microns. The total thickness of the heat sink 102 is no more than a few hundred microns, such as less than 400 microns. This makes it possible to obtain a thin wall made of a metal plate.

The heat sink 102 of the present invention improves thermal performance in that the fluid 110 used to absorb heat from the notebook computer is cooled to ambient temperature levels. Thus, no fluid 110 having a relatively high temperature (i.e., above ambient temperature level) returns to absorb heat as compared to conventional heat sink elements of liquid cooling systems. Accordingly, the heat dissipation member 102 improves cooling efficiency. Advantageously, the heat dissipating element 102 of the present invention provides a uniform heat distribution, i.e., the heat from the fluid 110 spreads evenly throughout the screen portion 108.

Fig. 1B is a side view of a heat dissipating component for a cooling system of a notebook computer according to an embodiment of the present invention. FIG. 1B is described in conjunction with the elements of FIG. 1A. Referring to FIG. 1B, a diagram 100B of a heat sink 102 and a screen portion 108 of a notebook computer is shown. As shown, the thickness of the heat dissipating element 102 is smaller than the screen portion 108. The heat dissipation member 102 has a uniform thickness. In one example, the thickness of the heat dissipating element 102 may be in the range of 0.20 millimeters to 0.99 millimeters.

Fig. 1C is a block diagram of a cooling system for a notebook computer provided by an embodiment of the invention. FIG. 1C is described in conjunction with the elements of FIGS. 1A and 1B. Referring to fig. 1C, a block diagram 100C is shown that includes a liquid cooling system 122, a notebook computer 124, a heat collection element 126, a keyboard portion 128, a micropump 130, a heat dissipation element 102, and a screen portion 108.

In another aspect, the present invention provides a cooling system 122 for a notebook computer 124, comprising:

a heat collecting element 126 disposed in a keyboard portion 128 of the notebook computer 124;

the heat dissipation element 102 of any of the preceding claims, disposed in a screen portion 108 of a notebook computer 124;

micropump 130 is used to move fluid 110 from heat collection element 126 through heat dissipation element 102 and back to heat collection element 126 in a closed loop fashion.

In another aspect, the present invention provides a notebook computer 124 including a liquid cooling system 122.

The liquid cooling system 122 for the notebook computer 124 is used to collect heat from the keyboard portion 128 in a fluid (e.g., the fluid 110), absorb heat from the fluid 110 heated in the keyboard portion 128 and dissipate heat, and cool the fluid 110 to move the fluid 110 back to the keyboard portion 128. Notebook computer 124 herein refers to any computing device having a screen and other components (e.g., keyboard portion, CPU, and/or GPU) that may be generating heat. Examples of notebook computer 124 may include, but are not limited to, a notebook computer, a personal computer, and the like.

The liquid cooling system 122 includes a heat collection element 126 disposed in a keyboard portion 128 of the notebook computer 124. The heat collecting element 126 is arranged in the keyboard section 128 so as to be able to absorb heat generated in the keyboard section 128 by, for example, a central processing unit (central processing unit, CPU) or a graphics processing unit (graphics processing unit, GPU). Heat is absorbed in the fluid 110.

The liquid cooling system 122 includes a heat dissipating element 102 disposed in the screen portion 108 of the notebook computer 124. The heat sink 102 has a gap for movement of the fluid 110 received from the heat collecting element 126. The fluid 110 circulates in a loop to transfer heat from the fluid 110 to the screen portion 108, where the heat dissipates into the environment.

The liquid cooling system 122 includes a micropump 130, the micropump 130 being configured to move the fluid 110 from the heat collection element 126 through the heat sink element 102 and back to the heat collection element 126 in a closed loop manner. Micropump 130 is used to move heated fluid 110 from heat collection element 126 to heat sink element 102 where fluid 110 is cooled.

According to one embodiment, the cooling system 122 may include tubing or micropipes to transport the fluid 110 between the screen portion 108, the keyboard portion 128, and the micropump 130.

In one example, a conventional heat dissipating element may have a volume of 12700 cubic millimeters, a pressure loss of 2700Pa, and thermal performance at 47 degrees Celsius at the inlet and 35.4 degrees Celsius at the conventional outlet. The heat sink 102 may have a volume of 5915 cubic millimeters, a pressure loss of 5000Pa, and thermal performance at 47 degrees Celsius at the inlet and 35.4 degrees Celsius at the outlet 112. Compared to conventional designs of heat dissipating elements, the heat dissipating element 102 of the present invention has a 50% reduction in volume compared to conventional designs (i.e., full coverage with a tabletop rear cover). However, the thermal performance of the heat dissipating element 102 of the present invention is unchanged. Therefore, the thermal efficiency does not decrease as the volume of the heat dissipation element 102 decreases (i.e., the weight decreases). Further, in the present invention, an increase from 2.7kPa to 5kPa is an acceptable increase without causing additional problems to the micropump 130, the micropump 130 can overcome the total pressure loss of the loop up to 50kPa or higher.

Advantageously, heat sink member 102 has additional advantages over conventional heat sink members because of the absence of the bypass portion of fluid 110. Conventional heat dissipating elements are not optimized because a portion of the conventional fluid finds a way to leave the conventional heat dissipating element at a still relatively high temperature (above ambient temperature level). Thus, conventionally, thermal efficiency is reduced, resulting in an increase in the overall cooling loop operating temperature. In the present invention, all of the fluid 110 has the opportunity to cool to ambient temperature levels, thereby avoiding bypass flow problems.

The liquid cooling system 122 of the present invention improves thermal performance in that the fluid 110 used to absorb heat from the notebook computer 124 is cooled to ambient temperature levels. Thus, no fluid 110 having a relatively high temperature (i.e., above ambient temperature level) is returned for heat absorption as compared to conventional liquid cooling systems. Thus, the cooling system 122 provides improved cooling. Advantageously, the heat dissipating element 102 of the present invention provides a uniform heat distribution, i.e., the heat from the fluid 110 spreads evenly throughout the screen portion 108. Furthermore, the total weight of the heat dissipating element 102 of the present invention is reduced as compared to conventional heat dissipating elements. In addition, the pressure loss is controlled and the mechanical strength is increased. Advantageously, the heat sink 102 design may maintain the pressure drop of the cooling system 122 at an acceptable level for a given micropump performance in lieu of a conventional serpentine or U-shaped heat sink unit design.

Fig. 2 is a diagram of a screen portion with a heat dissipating element for a notebook computer provided by an embodiment of the present invention. Fig. 2 is described in conjunction with the elements of fig. 1A, 1B, and 1C. Referring to FIG. 2, a diagram 200 of the screen portion 108 of the notebook computer 124 is shown. A substantially diagonal path 202, a substantially vertical path 204, an upper free triangle 206, a vertex 208, a lower free triangle 210, and a lower edge 212 are shown.

According to one embodiment, the rising portion (e.g., rising portion 116) is arranged along a substantially diagonal path 202 from the inlet (e.g., inlet 104) to the opposite vertex angle (e.g., vertex angle 118 of screen portion 108). In other words, the heat dissipating element 102 forms a right triangle, wherein the inlets 104 are arranged along the hypotenuse. The substantially diagonal path 202 provides the flow direction of the fluid 110. Through the substantially diagonal path 202, heat from the fluid 110 is dissipated by the screen portion 108. The screen portion 108 heats up uniformly along a substantially diagonal path 202, i.e., spreads the heat carried by the heating fluid 110. The heated screen portion 108 further dissipates heat into the environment.

According to one embodiment, the descending portion (e.g., descending portion 120) is arranged along a substantially vertical path 204 from the ascending portion 116 to the outlet (e.g., outlet 112). In other words, the heat dissipation element 102 forms a right triangle with the lowered portions 120 arranged along the vertical legs. The fluid 110 flowing in the substantially vertical path 204 is cooled to an ambient temperature level before the fluid 110 flows out to the keyboard portion 128. Thus, thermal performance is improved.

According to one embodiment, the screen portion 108 comprises an upper free triangle 206, the upper free triangle 206 being uncovered by the heat dissipating element 102, arranged in a top corner 208 of the screen portion 108 above the inlet 104. By the upper free triangle 206, the weight of the heat sink 102 and the weight of the fluid 110 are reduced. Therefore, in contrast to conventional liquid cooling systems, it is not necessary to ensure that the entire area of the screen portion 108 is in contact with the heat dissipating element 102.

According to one embodiment, the lower free triangle 210 of the screen portion 108 is not covered by the heat dissipating element 102, and is arranged on the lower edge 212 of the screen portion 108 between the inlet 104 and the outlet 112. In other words, there are two triangular portions, one below the heat sink element 102, i.e., the lower free triangle 210, and one above the heat sink element 102, i.e., the upper free triangle 206. Both triangular portions are free to dissipate heat to the environment. Accordingly, the total weight of the heat dissipating element 102 is reduced as compared to conventionally designed S-shaped or U-shaped heat dissipating units.

Fig. 3A is a diagram of a heat dissipating element provided by an embodiment of the present invention. Fig. 3A is described in conjunction with the elements of fig. 1A, 1B, and 1C. Referring to fig. 3A, a diagram 300A of a heat dissipating element 102 is shown. A flat sheet 302 and a shaped sheet 304 are shown.

The flat sheet 302 may also be referred to as a top plate having a flat surface. The shaped sheet 304 may also be referred to as a base plate having a surface with posts. The flat sheet 302 and the shaped sheet 304 may be made of metal with a gap therebetween for the flow of the fluid 110. The forming sheet 304 with internal columns supports the flat sheet 302 and the forming sheet 304 to avoid collapsing or expanding due to internal pressure changes that may occur over the operating range of the liquid cooling system. Furthermore, the two sheets, namely the flat sheet 302 and the shaped sheet 304, ensure that a proper contact is established between the heat dissipating element 102 and the screen portion 108.

Fig. 3B is an illustration of a side view of a heat dissipating element in a screen portion of a notebook computer provided by an embodiment of the invention. Fig. 3B is described in conjunction with the elements of fig. 1A, 1B, 1C, and 3A. Referring to fig. 3B, a diagram 300B of the heat dissipating element 102 in the screen portion 108 is shown. The heat sink 102 shown in fig. 3B has a flat sheet 302 and a shaped sheet 304 that are integrated to form the heat sink 102.

Fig. 3C is a cross-sectional view of a heat dissipating component provided by an embodiment of the present invention. Fig. 3C is described in conjunction with the elements of fig. 1A, 1B, 1C, 3A, and 3B. Referring to fig. 3C, a cross-sectional view 300C of the heat dissipating element 102 along line A-A' of fig. 3B is shown. The flat sheet 302, the shaped sheet 304, the channel 306, the cover 308, and a plurality of posts 310A, 310B, 310C, 310D, and 310E are shown.

According to one embodiment, the heat dissipating element 102 includes a flat sheet 302 and a shaped sheet 304, the flat sheet 302 and the shaped sheet 304 forming a channel 306 for the ascending portion 116 and the descending portion 120. The channel 306 enables movement of the fluid 110. Thus, heat in the fluid 110 flowing through the channel 306 is dissipated through the screen portion 108 in the rising portion 116. In addition, fluid 110 flowing through channel 306 cools in descending portion 120.

According to one embodiment, one of the flat sheet 302 and the shaped sheet 304 is integrally formed with the cover 308 of the screen portion 108. In this case, the heat dissipating element 102 is made of two metal compartments, one made of a metal sheet (for example, a flat sheet 302 having a thickness of about 100 μm), and the other plate (for example, a formed sheet 304) is integrated with a metal back cover or the like 308 on its inner surface (opposite to the surface contacting the environment). In other words, the respective walls of the heat dissipating element 102 are replaced by the cover 308, i.e. a support is machined (or etched) on the inner surface of the cover 308, such that the inner surface works as another wall of the heat dissipating element 102 and provides mechanical structural support for the heat dissipating element 102. Thus, the weight of the cooling system 122 is generally saved.

According to one embodiment, the shaped sheet 304 includes a plurality of posts 310A, 310B, 310C, 310D, and 310E formed within the channel 306 for contacting the flat sheet 302 and supporting the channel 306. In one example, a channel is formed between columns 310A and 310B, another channel is formed between columns 310B and 310C, another channel is formed between columns 310C and 310D, and another channel is formed between columns 310D and 310E. The plurality of posts 310A, 310B, 310C, 310D, and 310E each provide mechanical strength to the channel 306. Advantageously, the mechanical strength ensures a stable thermal contact with the cover 308 throughout the heat dissipating operation.

According to one embodiment, the channel 306 and one or more edges of the plurality of posts 310A, 310B, 310C, 310D, and 310E are connected to the flat sheet 302 by a laser welding process. The laser welding process is used to combine the two parts, i.e., posts 310A, 310B, 310C, 310D, 310E and flat sheet 302, in such a way that the top surface of the posts forms a connection area. In one example, a laser welding process is also used along one or more edges, i.e., the peripheral edge, in order to form a closed gap (cavity or channel) that is sealed to protect the fluid 110 from leakage risk.

The heat dissipating element 102 has an internal pressure that may be higher than ambient pressure or lower than or equal to ambient pressure. In all these cases, the heat sink member 102 does not lose its shape and ensures good thermal contact with the metal table top cover. The plurality of posts 310A, 310B, 310C, 310D, and 310E ensure that there is no warpage (protrusions or dimples) from one side over the entire operating pressure range surface area. Thus, there is good thermal contact with the metal table top cover. Further, from the other side, the plurality of columns 310A, 310B, 310C, 310D, and 310E cause an increase in pressure loss of the fluid 110 through the heat dissipating element 102.

Thus, the plurality of posts 310A, 310B, 310C, 310D, and 310E are well designed from the standpoint of the tradeoff between the internal pressure loss of the fluid 110 and the mechanical strength of the walls of the heat sink 102, so as to ensure surface flatness (i.e., good thermal contact with the metal table top cover) throughout the operating range. Since the total thickness of the heat dissipation member 102 is almost no more than several hundred micrometers, there is a thin wall that can be made of sheet metal. Thus, the plurality of posts 310A, 310B, 310C, 310D, and 310E prevent any deformation of the heat dissipating element 102.

Fig. 4A is a diagram illustrating the shape of a plurality of posts of a shaped sheet of a heat dissipating element provided by an embodiment of the present invention. Fig. 4A is described in conjunction with the elements of fig. 1A, 1B, 1C, 3A, 3B, and 3C. Referring to fig. 4A, a diagram 400A of the pillar shape in a plurality of pillars 310A, 310B, 310C, 310D, and 310E is shown. A first column 402 having a circular shape, a second column 404 having a capsule shape, and a third column 406 having an elongated wall shape are shown.

According to one embodiment, the plurality of posts 310A, 310B, 310C, 310D, and 310E are formed to have a circular shape, a capsule shape, or an elongated wall shape. The first post 402 having a circular shape supports the lowest pressure drop that achieves a given thermal performance of the heat dissipating element 102. Such a circular column may be replaced by a segmented column, i.e. a capsule-shaped column. The second post 404, having a capsule shape, facilitates the connection of the two portions of the heat dissipating element 102 (i.e., the flat sheet 302 and the shaped sheet 304). Alternatively, the segmented column may be elongated to organize the columns of the longitudinal shape, i.e., the third column 406. In such a column, the grooves provide an arrangement of fluid paths. In one example, a circular shape, a capsule shape, and an elongated wall shape are used herein for exemplary purposes, and any suitable shape may be used for the plurality of posts 310A, 310B, 310C, 310D, and 310E.

Fig. 4B is an illustration of a three-dimensional view of a shaped sheet including pillars having a capsule shape provided by an embodiment of the present invention. Fig. 4A is described in conjunction with the elements of fig. 1A, 1B, 1C, 3A, 3B, 3C, and 4A. Referring to fig. 4B, a diagram 400B of a shaped sheet 304 including a post having a capsule shape is shown. The shaped sheet 304 of the present invention includes a post, such as a second post 404 having the shape of a capsule.

Fig. 4C is an illustration of a three-dimensional view of a formed sheet including posts having an elongated wall shape provided by an embodiment of the present invention. Fig. 4C is described in conjunction with the elements of fig. 1A, 1B, 1C, 3A, 3B, 3C, and 4A. Referring to fig. 4C, a diagram 400C of a formed sheet 304 including a post having an elongated wall shape is shown. The shaped sheet 304 of the present invention includes a post, such as a third post 406 having an elongated wall shape.

Fig. 5A is an illustration of a formed sheet formed by an etching process provided by an embodiment of the present invention. Fig. 5A is described in conjunction with the elements of fig. 3A, 3B, 3C, and 4A. Referring to fig. 5A, a diagram 500A of a formed sheet 304 formed by an etching process is shown.

According to one embodiment, the shaped sheet 304 is formed by an etching process. In one example, the shaped sheet 304 herein has a plurality of posts, such as a first post 402 having a circular shape. The etching process is used to provide the pillars of the shaped sheet 304 with a desired shape, such as a circular shape, a capsule shape, or an elongated wall shape. The shaped sheets 304 formed by the etching process have improved thermal efficiency because they are able to better transfer heat through their solids.

Fig. 5B is an illustration of a formed sheet formed by a stamping process provided by an embodiment of the present invention. Fig. 5B is described in conjunction with the elements of fig. 3A, 3B, 3C, and 4A. Referring to fig. 5B, a diagram 500B of a formed sheet 304 formed by a stamping process is shown.

According to one embodiment, the shaped sheet 304 is formed by a stamping process. The etching manufacturing process is replaced with a punching process to enable the weight of the heat dissipation member 102 to be reduced. In one example, the shaped sheet 304 herein has a plurality of posts, such as a first post 402 having a circular shape. In contrast to the first post 402 of fig. 5A, which has a regular circular shape, the first post 402 of fig. 5B may have a deformed circular shape (i.e., the two perpendicular diameters may be different). The first post 402 formed by stamping may have sloped sides forming a truncated cone shape. The formed sheet 304 formed by the stamping process has empty spaces inside, and the bulk solids are replaced with air. Accordingly, the heat transfer capability may be reduced compared to the shaped sheet 304 formed by the etching process. In one example, an etching process and a stamping process are used herein for exemplary purposes, and any suitable process may be used to form the shaped sheet 304.

Advantageously, the variable column design supports the option of cheaper manufacturing processes. Furthermore, the variable column design supports optimal internal routing of fluid 110 based on specific boundaries of liquid cooling system 122.

Fig. 6 is a diagram of a heat dissipating component with a high thermal conductivity plate provided by an embodiment of the present invention. Fig. 6 is described in conjunction with the elements of fig. 1A, 1B, and 1C. Referring to fig. 6, a diagram 600 of the heat dissipating element 102 is shown. The high thermal conductivity plate 602, heat dissipation element 102, lower corner 106 and screen portion 108 are shown.

According to one embodiment, the heat sink member 102 further includes a high thermal conductivity plate 602 having a lateral thermal conductivity greater than 500W/mk. The heat sink 102 with the high thermal conductivity plate 602 is useful when the metal back cover of a given notebook computer has limited heat dissipation capability due to being thin or made of an alloy with low thermal conductivity or both. In one example, the lateral thermal conductivity is along the plane of the material of the high thermal conductivity plate 602.

According to one embodiment, the high thermal conductivity plate 602 is arranged to cover the lower corner 106 of the screen portion 108 where the inlet 104 is located. Advantageously, the high thermal conductivity plate 602 enables heat to be dissipated along the liquid inlet region (where the fluid 110 has the highest temperature). Thus, the maximum temperature of the hot spot area is reduced. In one example, a high thermal conductivity plate 602 may be placed along the entire heat dissipating element 102 to improve thermal performance.

The heat sink 102 is integral with a high thermal conductivity plate 602, such as a graphite sheet attached to a partial region of the inlet 104 of the heat sink 102. The graphite flake has a high thermal conductivity (600W/mK to 800W/mK) in the transverse direction. In one example, the graphite sheet has a thickness of 50 microns. Such graphite sheets diffuse heat flux along their surfaces. Furthermore, the maximum temperature in the hot spot area is reduced.

Fig. 7 is a flowchart of a method of manufacturing a heat dissipating member for a cooling system of a notebook computer according to an embodiment of the present invention. Fig. 7 is described in conjunction with the elements of fig. 1A, 1B, 1C, 3A, 3B, and 3C. Referring to fig. 7, a method 700 is shown. Method 700 includes steps 702 and 704.

In another aspect, the present invention provides a method 700 of manufacturing a heat dissipating component 102 for a cooling system 122 of a notebook computer 124, comprising:

the rising portion 116 is formed to carry the fluid 110 from the inlet 104 disposed in the lower corner 106 of the screen portion 108 of the notebook computer 124 to an opposite vertex angle, such as the vertex angle 118 of the screen portion 108;

a descending portion 120 is formed, the descending portion 120 being arranged to carry the fluid 110 from the ascending portion 116 to the outlet 112 arranged in the opposite lower corner 114 of the screen portion 108.

In step 702, the method 700 includes: the rising portion 116 is formed to carry the fluid 110 from the inlet 104 disposed in the lower corner 106 of the screen portion 108 of the notebook computer 124 to an opposite vertex angle, such as the vertex angle 118 of the screen portion 108. The rising portion 116 is formed to carry the fluid 110 to enable heat dissipation in the fluid 110 through the screen portion 108 (i.e., the back cover) of the notebook computer 124. In addition, the more the surface of the rear cover is heated, the more efficient the heat dissipation. Due to the thermal conductivity of the metallic back cover, the back cover heats uniformly along the inlet 104, i.e., spreads the heat carried by the heating fluid 110. The heated back cover further dissipates heat into the environment.

In step 704, the method 700 includes forming the lowered portion 120, the lowered portion 120 being arranged to carry the fluid 110 from the raised portion 116 to the outlet 112 arranged in the opposite lower corner 114 of the screen portion 108. The fluid 110 is cooled to an ambient temperature level before the fluid 110 flows out to the keyboard portion 128 to avoid heating the fluid 110 back to the keyboard portion 128. Thus, the present invention provides for the design of the outlet 112 as an extended downward region, i.e., the drop down portion 120. Advantageously, the drop-down portion 120 allows the fluid 110 to flow downwardly with a large contact area with the back cover to enable the fluid 110 to cool to room temperature levels.

According to one embodiment, the method 700 further includes forming the channels 306 using the flat sheet 302 and the shaped sheet 304 to form the ascending portion 116 and the descending portion 120. The channel 306 enables movement of the fluid 110. Thus, heat in the fluid 110 flowing through the channel 306 is dissipated through the screen portion 108 in the rising portion 116. In addition, fluid 110 flowing through channel 306 cools in descending portion 120.

According to one embodiment, the method 700 further includes forming one of the flat sheet 302 and the shaped sheet 304 integrally with the cover 308 of the screen portion 108. In this case, the heat dissipating element 102 is formed of two metal compartments, one made of a metal sheet (for example, a flat sheet 302 having a thickness of about 100 μm), and the other plate (for example, a formed sheet 304) is integrated with a metal back cover or the like 308 on its inner surface (opposite to the surface contacting the environment). In other words, the respective walls of the heat dissipating element 102 are replaced by the cover 308, i.e. a support is machined (or etched) on the inner surface of the cover 308, such that the inner surface works as another wall of the heat dissipating element 102 and provides mechanical structural support for the heat dissipating element 102. Thus, weight is saved as a whole.

According to one embodiment, in method 700, a shaped sheet 304 is formed with a plurality of posts 310A, 310B, 310C, 310D, and 310E within channels 306 and is used to contact flat sheet 302 and support channels 306. Thus, the channel 306 is provided with mechanical strength by the plurality of posts 310A, 310B, 310C, 310D, and 310E. Advantageously, the mechanical strength ensures a stable thermal contact with the metallic back cover throughout the heat dissipating operation.

According to one embodiment, method 700 further includes connecting channel 306 and one or more edges of the plurality of posts 310A, 310B, 310C, 310D, and 310E to flat sheet 302 using a laser welding process. The laser welding process is used to combine the two parts, i.e., posts 310A, 310B, 310C, 310D, 310E and flat sheet 302, in such a way that the top surface of the posts forms a connection area. In one example, a laser welding process is also used along one or more edges, i.e., peripheral edges, in order to form a closed gap (cavity or channel).

According to one embodiment, in method 700, a plurality of posts 310A, 310B, 310C, 310D, and 310E are formed to have a circular shape, a capsule shape, or an elongated wall shape. The plurality of posts 310A, 310B, 310C, 310D, and 310E having a circular shape support the lowest pressure drop that achieves a given thermal performance of the heat dissipating element 102. The plurality of posts 310A, 310B, 310C, 310D, and 310E having a capsule shape facilitate the connection of the two portions of the heat dissipating element 102 (i.e., the flat sheet 302 and the shaped sheet 304). Alternatively, the capsule-shaped column may be elongated to organize the longitudinal-shaped column. In such a column, the grooves provide an arrangement of fluid paths. In one example, a circular shape, a capsule shape, and an elongated wall shape are used herein for exemplary purposes, and any suitable shape may be used for the plurality of posts 310A, 310B, 310C, 310D, and 310E.

According to one embodiment, in method 700, the shaped sheet 304 is formed by an etching process or a stamping process. An etching process or a stamping process is used to provide the pillars of the shaped sheet 304 with a desired shape, such as a circular shape, a capsule shape, or an elongated wall shape. The formed sheets 304 formed by the etching process have improved thermal efficiency because they are better able to transfer heat through their bodies. A stamping process may be used instead of the etching process to enable a weight reduction of the heat dissipation member 102. In one example, an etching process and a stamping process are used herein for exemplary purposes, and any suitable process may be used to form the shaped sheet 304.

The method 700 of the present invention improves thermal performance in that the fluid 110 used to absorb heat from the notebook computer 124 is cooled to ambient temperature. Thus, no fluid 110 having a relatively high temperature (i.e., above ambient temperature level) is returned for heat absorption as compared to conventional methods. Thus, method 700 improves cooling performance. Advantageously, the heat dissipating element 102 of the present invention provides a uniform heat distribution, i.e., the heat from the fluid 110 spreads evenly throughout the screen portion 108. Furthermore, the total weight of the heat dissipating element 102 of the present invention is reduced as compared to conventional heat dissipating elements. In addition, the pressure loss is controlled and the mechanical strength is increased.

Table 1 is shown providing different parameter values for a first conventional heat sink element, the heat sink element 102 of the present invention, and a second conventional heat sink element. The first conventional heat sink element occupies the full area of the screen portion, having an area of 31726 square millimeters and a perimeter of 801 millimeters. The second conventional heat sink element has a serpentine shape with an area of 19464 square millimeters and a perimeter of 3268 millimeters. The area of the heat dissipating element 102 of the present invention is 14762 square millimeters and the perimeter is 864 millimeters.

TABLE 1

Modifications may be made to the embodiments of the invention described above without departing from the scope of the invention, as defined in the appended claims. Expressions such as "comprising," "combining," "having," "being/being" and the like, which are used to describe and claim the present invention, are intended to be interpreted in a non-exclusive manner, i.e. to allow for items, components or elements that are not explicitly described to exist as well. Reference to the singular is also to be construed to relate to the plural. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and/or does not preclude the incorporation of features of other embodiments. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable combination or as in any other described embodiment of the invention.

Claims

1. A heat sink member (102) for a liquid cooling system (122) of a notebook computer (124), comprising:

an inlet (104) arranged in a lower corner (106) of a screen portion (108) of the notebook computer (124) and for receiving a heating fluid (110);

an outlet (112) arranged in an opposite lower corner (114) of the screen portion (108) to return cooling fluid (110);

-a rising portion (116) arranged to carry the fluid (110) from the inlet (104) to a top corner (118) of the screen portion (108);

-a descending portion (120) arranged to carry the fluid (110) from the ascending portion (116) to the outlet (112).

2. The heat dissipating element (102) of claim 1, wherein the rising portion (116) is arranged along a substantially diagonal path (202) from the inlet (104) to the opposite vertex angle of the screen portion (108).

3. The heat dissipating element (102) according to claim 1 or 2, wherein the descending portion (120) is arranged along a substantially vertical path (204) from the ascending portion (116) to the outlet (112).

4. The heat sink element (102) according to any of the preceding claims, wherein the heat sink element (102) is formed to cover less than 50% of the total area of the screen portion (108) of the notebook computer (124).

5. The heat dissipating element (102) of any of the above claims, wherein an area ratio between an area covered by the heat dissipating element (102) and the total area of the screen portion (108) is 1:4 or greater.

6. The heat spreading element (102) according to any one of the preceding claims, wherein an inlet/outlet ratio between an area covered by the rising portion (116) and an area covered by the falling portion (120) is substantially 1:1.

7. The heat dissipating element (102) according to any of the preceding claims, wherein the heat dissipating element (102) is formed such that the screen portion (108) comprises an upper free triangle (206), which upper free triangle (206) is not covered by the heat dissipating element (102), arranged in a top corner (208) of the screen portion (108) above the inlet (104).

8. The heat dissipating element (102) according to any of the preceding claims, wherein the heat dissipating element (102) is formed such that a lower free triangle (210) of the screen portion (108) is not covered by the heat dissipating element (102), arranged on a lower edge (212) of the screen portion (108) between the inlet (104) and the outlet (112).

9. The heat dissipating element (102) of any of the above claims, wherein the heat dissipating element (102) comprises a flat sheet (302) and a shaped sheet (304), the flat sheet (302) and shaped sheet (304) forming a channel (306) for the rising portion (116) and the falling portion (120).

10. The heat dissipating element (102) of claim 9, wherein one of the flat sheet (302) and the shaped sheet (304) is integrally formed with a cover (308) of the screen portion (108).

11. The heat dissipating element (102) of claim 9 or 10, wherein the shaped sheet (304) comprises a plurality of posts (310A, 310B, 310C, 310D, 310E) formed within the channel (306) for contacting the flat sheet (302) and supporting the channel (306).

12. The heat dissipating element (102) of claim 11, wherein said channel (306) and one or more edges of said plurality of posts (310A, 310B, 310C, 310D, 310E) are connected to said flat sheet (302) by a laser welding process.

13. The heat dissipating element (102) of claim 11 or 12, wherein said plurality of posts (310A, 310B, 310C, 310D, 310E) are formed to have a circular shape, a capsule shape, or an elongated wall shape.

14. The heat sink element according to any of the claims 9 to 13, characterized in that the shaped sheet (304) is formed by an etching process or a stamping process.

15. The heat spreading element (102) according to any one of the preceding claims, further comprising a high thermal conductivity plate (602) having a lateral thermal conductivity greater than 500W/mk.

16. The heat dissipating element (102) of claim 15, wherein the high heat conducting plate (602) is arranged to cover the lower corner (106) of the screen portion (108) where the inlet (104) is located.

17. A cooling system (122) for a notebook computer (124), comprising:

a heat collecting element (126) arranged in a keyboard portion (128) of the notebook computer (124);

the heat dissipation element (102) according to any one of the preceding claims, arranged in a screen portion (108) of the notebook computer (124);

a micropump (130) for moving fluid (110) in a closed loop from the heat collecting element (126) through the heat dissipating element (102) and back to the heat collecting element (126).

18. A notebook computer (124), characterized by comprising a cooling system (122) according to claim 17.

19. A method (700) of manufacturing a heat sink (102) for a cooling system (122) of a notebook computer (124), comprising:

forming a rising portion (116) to carry fluid (110) from an inlet (104) disposed in a lower corner (106) of a screen portion (108) of the notebook computer (124) to opposite vertex corners of the screen portion (108);

-forming a descending portion (120), the descending portion (120) being arranged to carry the fluid (110) from the ascending portion (116) to an outlet (112) arranged in an opposite lower corner (114) of the screen portion (108).

20. The method (700) of claim 19, including forming the channel (306) using a flat sheet (302) and a shaped sheet (304) to form the ascending portion (116) and the descending portion (120).

21. The method (700) of claim 20, including integrally forming one of the flat sheet (302) and the shaped sheet (304) with a cover (308) of the screen portion (108).

22. The method (700) of claim 20 or 21, wherein the shaped sheet (304) is formed with a plurality of posts (310A, 310B, 310C, 310D, 310E) within the channel (306) and is used to contact the flat sheet (302) and support the channel (306).

23. The method (700) of claim 22, comprising connecting one or more edges of the channel (306) and the plurality of posts (310A, 310B, 310C, 310D, 310E) to the flat sheet (302) using a laser welding process.

24. The method (700) of claim 22 or 23, wherein the plurality of posts (310A, 310B, 310C, 310D, 310E) are formed to have a circular shape, a capsule shape, or an elongated wall shape.

25. The method (700) according to any one of claims 20 to 24, wherein the shaped sheet (304) is formed by an etching process or a stamping process.