HEAT TRANSFER DEVICE

Abstract

A heat transfer device configured to be independently fixed and densely mounted. The heat transfer device includes: a main body formed of a metallic material and forming a tube sealed to maintain a vacuum therein; and a thermally conductive layer having elasticity and adhered around the main body.

Claims

1. A heat transfer device comprising: a main body formed of a metallic material and forming a tube sealed to maintain a vacuum therein; and a thermally conductive layer having elasticity and flexibility and adhered around the main body.

2. The heat transfer device of claim 1, wherein the thermally conductive layer is a thermal sheet extending in a length direction of the main body with both widthwise ends of the thermal sheet being in contact with each other or separate from each other.

3. The heat transfer device of claim 1, wherein the thermally conductive layer is adhered or bonded to the main body by dipping an outer surface of the main body in a thermally conductive liquid-phase rubber or resin in which thermally conductive particles are mixed and dispersed and then curing the thermally conductive liquid-phase rubber or resin, or by spraying the thermally conductive liquid-phase rubber or resin onto the outer surface of the main body and then curing the thermally conductive liquid-phase rubber or resin.

4. The heat transfer device of claim 1, wherein the heat transfer device is a heat pipe, a heat spreader, or a vapor chamber.

5. The heat transfer device of claim 1, wherein the thermally conductive layer is electrically insulative.

6. The heat transfer device of claim 1, wherein the main body is inserted in an accommodation groove of a metal case such that a portion of the thermally conductive layer corresponding to a lower surface of the main body is brought into contact with a bottom of the accommodation groove and an upper surface of the main body is exposed for direct or indirect thermal contact with a heat source, wherein an outer surface of the thermally conductive layer has self-adhesion such that the thermally conductive layer is adhered to the bottom of the accommodation groove.

7. The heat transfer device of claim 6, wherein portions of the thermally conductive layer corresponding to lateral sides of the main body are elastically brought into contact with both sidewalls of the accommodation groove.

8. The heat transfer device of claim 1, wherein the thermally conductive layer is a thermally conductive silicone rubber or a thermally conductive acrylic resin.

9. A heat transfer device comprising: a main body formed of a metallic material and forming a tube sealed to maintain a vacuum therein; a first thermally conductive layer having elasticity and a self-adhesive outer surface and adhered to a surface of the main body; and a second thermally conductive layer having elasticity and a self-adhesive outer surface and adhered to an opposite surface of the main body.

10. The heat transfer device of claim 9, wherein the first thermally conductive layer has greater self-adhesion and less thermal conductivity than the second thermally conductive layer, and the first thermally conductive layer is brought into contact with a cooling case, and the second thermally conductive layer is brought into contact with a heat source.

11. A heat transfer device comprising: a main body formed of a metallic material and forming a tube sealed to maintain a vacuum therein; a thermally conductive layer having elasticity and flexibility and adhered around the main body; and a thermally conductive particle layer formed of thermally conductive particles attached to an outer surface of the thermally conductive layer.

12. The heat transfer device of claim 11, wherein the thermally conductive particles are metal powder, carbon powder, ceramic powder, graphite power, or carbon fiber having high thermal conductivity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above objects and other advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

[0026] FIG. 1 is a view illustrating a state in which a heat pipe is applied to a smartphone according to an embodiment of the present invention;

[0027] FIG. 2 is a partial perspective view illustrating a cross-section of the heat pipe;

[0028] FIGS. 3A and 3B are views illustrating how the heat pipe is placed in a accommodation groove; and

[0029] FIG. 4 is a cross-sectional view illustrating a heat pipe according to another embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0030] Technical terms used herein are only for explaining specific embodiments while not limiting the present invention. In addition, unless otherwise defined, technical terms used herein have the same meaning as commonly understood by those of ordinary skill in the art and will not be interpreted in an overly broad or narrow sense. In addition, if technical terms used herein are incorrect to exactly express the idea of the present invention, the technical terms should be interpreted as terms by which those of ordinary skill in the art can correctly understand the idea of the present invention. In addition, general terms used herein may be interpreted as defined in dictionaries or according to the contextual meanings, and should not be interpreted in an overly narrow sense.

[0031] FIG. 1 illustrates a state in which a heat pipe 100 is applied to a smartphone according to an embodiment of the present invention.

[0032] A battery 14 may be provided on a back cover 10 of the smartphone, and a circuit board 16 on which a plurality of electronic components are mounted may be provided in a region surrounding the battery 14.

[0033] In FIG. 1, the back cover 10 formed of a metallic material is shown as an example of a heat releasing object. However, the present invention is not limited thereto. For example, another metal case of a heat generating unit may be considered.

[0034] A heat source generating a large amount of heat such as an application processor (AP) among the electronic components mounted on the circuit board 16 is brought into contact with the heat pipe 100 such that heat generated from the heat source may be rapidly dissipated through the back cover 10.

[0035] To this end, the heat pipe 100 is fixedly inserted into an accommodation groove 12 formed in the back cover 10, and as described later, the heat pipe 100 may be fixed to the back cover 10 owing to self-adhesion of a thermally conductive layer 120.

[0036] FIG. 2 is a partial perspective view illustrating a cross-section of the heat pipe 100.

[0037] The heat pipe 100 includes: a metallic main body 110 forming a tube sealed to maintain a vacuum therein; and the thermally conductive layer 120 having elasticity and adhered around the main body 110.

[0038] The main body 110 is formed of a metallic material such as copper or aluminum.

[0039] The thermally conductive layer 120 may be a thermal sheet formed of a thermally conductive silicone rubber or a thermally conductive acrylic resin. In this case, the thermal sheet may surround the main body 110, and both widthwise ends of the thermal sheet may be in contact with each other or may be separate from each other on a lower surface of the main body 110.

[0040] Alternatively, the thermally conductive layer 120 may be adhered or bonded to the main body 110 by dipping the main body 110 in a thermally conductive liquid-phase rubber or resin in which thermally conductive particles are mixed and dispersed and then curing the thermally conductive liquid-phase rubber or resin, or by spraying the thermally conductive liquid-phase rubber or resin onto an outer surface of the main body 110 and then curing the thermally conductive liquid-phase rubber or resin with heat or ultraviolet (UV) rays.

[0041] The thermally conductive layer 120 may form a closed loop in a width direction of the main body 110 and may extend in a length direction of the main body 110.

[0042] The thermally conductive layer 120 may include thermally-conductive, electrically-insulative particles such as ceramic powder, and thus the thermally conductive layer 120 may be electrically insulative. When only the thermal conductivity of the thermally conductive layer 120 is considered, the thermally conductive layer 120 may include metal powder, carbon powder, graphite powder, or graphite fiber. In this case, the thermally conductive layer 120 may have high thermal conductivity even though having electrical conductivity.

[0043] The thermally conductive layer 120 has elasticity and flexibility because the thermally conductive layer 120 has a structure based on a silicone rubber or acrylic resin. Therefore, the heat pipe 100 may be forcibly inserted into the accommodation groove 12 to bring the thermally conductive layer 120 into elastic contact with inner walls of the accommodation groove 12. In this case, since gaps between the heat pipe 100 and the accommodation groove 12 are filled with the thermally conductive layer 120, reliable thermal contact may be made over a relatively large area, thereby improving heat transfer efficiency.

[0044] The thickness of the thermally conductive layer 120 may be less than the thickness of the main body 110. In a non-limiting example, the thickness of the thermally conductive layer 120 may range from about 0.02 mm to about 0.3 mm.

[0045] The thermally conductive layer 120 may be discretely formed in the length direction of the thermally conductive layer 120. In this case, the total length of the thermally conductive layer 120 may be adjusted to be equal to or greater than half () the total length of the main body 110 for sufficient heat transfer.

[0046] The outer surface of the thermally conductive layer 120 may have self-adhesion. In this case, a portion of the thermally conductive layer 120 formed on a lower surface of the main body 110 may be adhered to the bottom of the accommodation groove 12 of the back cover 10. Therefore, the heat pipe 100 may be fixed to the accommodation groove 12 without additionally using a piece of thermally conductive double-sided adhesive tape or a thermally conductive adhesive.

[0047] In addition, the heat pipe 100 may be arranged on a sheet of release paper or release film by using the self-adhesion of the outer surface of the thermally conductive layer 120.

[0048] FIGS. 3A and 3B illustrate how the heat pipe 100 is placed in the accommodation groove 12.

[0049] The heat pipe 100 may be forcibly inserted into the accommodation groove 12 of the back cover 10 and elastically brought into contact with the bottom and both sidewalls of the accommodation groove 12 owing to the elasticity of the thermally conductive layer 120 so that thermal contact between the heat pipe 100 and the back cover 10 may be reliably improved.

[0050] In particular, if the outer surface of the thermally conductive layer 120 has self-adhesion, the thermally conductive layer 120 may be adhered to the bottom and/or both sidewalls of the accommodation groove 12 by the self-adhesion of the thermally conductive layer 120.

[0051] Therefore, unlike the related art, it is not necessary to use a piece of thermally conductive double-sided adhesive tape or a thermally conductive adhesive, or shape a piece of thermally conductive double-sided adhesive tape according to the shape of the heat pipe 100 so as to fix the heat pipe 100 to the accommodation groove 12. Therefore, simple manufacturing processes and low manufacturing costs may be guaranteed while enabling high-density mounting of the heat pipe 100.

[0052] In addition, since only the thermally conductive layer 120 having elasticity and surrounding the main body 110 of the heat pipe 100 is placed between the main body 110 and the accommodation groove 12 when fixedly inserting the heat pipe 100 into the accommodation groove 12, the heat pipe 100 may be easily mounted in the accommodation groove 12 and may have high thermal conductivity for improved heat transfer efficiency.

[0053] Likewise, on the heat pipe 100 fixedly inserted in the accommodation groove 12, the circuit board 16 or another heat source may be mounted directly or using a simple thermal sheet therebetween, thereby improving heat transfer efficiency and the yield of production.

[0054] In the above-described embodiment, the thermally conductive layer 120 entirely surrounds the main body 110. However, this is a non-limiting example. In another example, thermally conductive layers 120 may be adhered to only upper and lower surfaces of the main body 110.

[0055] In this case, the upper and lower thermally conductive layers 120 may have different thermal conductivity and self-adhesion characteristics.

[0056] For example, the upper thermally conductive layer 120 may have thermal conductivity less than the lower thermally conductive layer 120. In this case, the upper thermally conductive layer 120 may be brought into contact with a cooling case, and the lower thermally conductive layer 120 may be brought into contact with a heat source.

[0057] In addition, the upper thermally conductive layer 120 may have self-adhesion greater than the lower thermally conductive layer 120. In this case, the upper thermally conductive layer 120 may be brought into contact with a cooling case, and the lower thermally conductive layer 120 may be brought into contact with a heat source, such that when the cooling case is lifted, the heat pipe 100 may be on the cooling case owing to the upper thermally conductive layer 120.

[0058] FIG. 4 is a cross-sectional view illustrating a heat pipe 200 according to another embodiment.

[0059] In the current embodiment, thermally conductive particles are attached to an outer surface of a thermally conductive layer 220 to form a thermally conductive particle layer 230 by a high-temperature and high-pressure, vacuum, or plasma coating method as shown in an enlarged circle of FIG. 4, so as to substantially increase the surface area of the heat pipe 200.

[0060] The thermally conductive particles may be metal powder, carbon powder, graphite powder, ceramic powder, or carbon fiber having high thermal conductivity.

[0061] As a result, since the surface area of the thermally conductive layer 220 is increased, heat may rapidly transfer to the thermally conductive layer 220 and then to another object such as the back cover 10.

[0062] While the present invention has been described according to the embodiments, those of ordinary skill could understand that various modifications can be made from the embodiments. Therefore, the spirit and scope of the present invention are not limited to the embodiments, but should be construed by the appended claims.