HEAT SINK WITH VAPOR CHAMBER

Abstract

A heat sink includes a tank and a plate covering on the tank and hermetically engaging with the tank. The tank includes a base for absorbing heat from heat-generating members and a first wick layer formed at an inner face of base. The plate has a second wick layer formed at an inner face thereof. A chamber is defined between the tank and the plate and contains working fluid therein. An artery mesh is located in the chamber between the tank and the plate. The artery mesh is in porosity communication with the first wick layer and the second wick layer.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat sink with vapor chamber, and more particularly to a heat sink with vapor chamber having wick structure.

2. Description of Related Art

It is well known that heat is generated during operations of electronic components, such as integrated circuit chips. To ensure normal and safe operations, cooling devices such as heat sinks are often employed to dissipate the generated heat away from these electronic components.

As progress continues to be made in the electronics art, more components on the same real estate generate more heat. The heat sinks used to cool these chips are accordingly made larger in order to possess a higher heat removal capacity, which causes the heat sinks to have a much larger footprint than the chips. Generally speaking, a heat sink is more effective when there is a uniform heat flux applied over an entire base of the heat sink. When a heat sink with a large base is attached to an integrated circuit chip with a much smaller contact area, there is significant resistance to the flow of heat to the other portions of the heat sink base which are not in direct contact with the chip.

A mechanism for overcoming the resistance to heat flow in a heat sink base is to attach a heat spreader to the heat sink base or directly make the heat sink base as a heat spreader. Typically, the heat spreader includes a vacuum chamber defined therein, a wick structure provided in the chamber and lining an inside wall of the chamber, and a working fluid contained in chamber. As an integrated circuit chip is maintained in thermal contact with the heat spreader, the working fluid contained in the wick structure corresponding to a hot contacting location vaporizes. The vapor then spreads to fill the chamber, and wherever the vapor comes into contact with a cooler surface of the chamber, it releases its latent heat of vaporization and condenses. The condensate returns to the hot contacting location via a capillary force generated by the wick structure. Thereafter, the condensate frequently vaporizes and condenses to form a circulation to thereby remove the heat generated by the chip.

As progress continues to be made in electronics area, the electronic components are made to be more powerful while occupying a smaller size. Thus, a heating area of the heat spreader needs to transfer more heat to a cooling area of the heat spreader. In contrast, the heating area of the heat spreader is decreased as the size of the electronic component is decreased, and the cooling area of the heat spreader is commensurately increased. Therefore, the heat flux density between the heating and the cooling areas of the heat spreader is increased. Accordingly, the wick structure needs to have more powerful heat transfer capability. However, the wick structure of the heat spreader selected from the conventional types, such as mesh, fiber, fine grooves, and sintered powder, cannot satisfy such requirement, which further limits the increase for the heat transfer capability of the heat spreader.

What is needed therefore is to provide a heat sink with vapor chamber having wick structures which achieves good heat dissipation performance.

SUMMARY OF THE INVENTION

A heat sink in accordance with a preferred embodiment of the present invention comprises a tank and a plate covering on the tank and hermetically engaging with the tank. The tank comprises a base for absorbing heat from heat-generating members and a first wick layer formed at an inner face of base. The plate has a second wick layer formed at an inner face thereof. A chamber is defined between the tank and the plate and contains working fluid therein. An artery mesh is located in the chamber between the tank and the plate. The artery mesh is in porosity communication with the first wick layer and the second wick layer.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present heat sink with vapor chamber can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present portable projector using a related heat dissipation system. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an isometric, exploded view of a heat sink in accordance with a preferred embodiment of the present invention;

FIG. 2 is an assembled view of FIG. 1;

FIG. 3 is an inverted view of FIG. 2;

FIG. 4 is a sectional view of FIG. 2 taking along a line IV-IV; and

FIG. 5 is an enlarged view of a part V shown in FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, the heat sink comprises a heat spreader 10 and a plurality of fins 30 arranged on the heat spreader 10.

Referring also to FIGS. 3-5, the heat spreader 10 comprises a tank 110 and a top plate 150 hermetically covering on the tank 110, thereby defining a chamber 180 between the tank 110 and the plate 150. The tank 110 comprises a cuboids body 111 and a flange 112 circumferentially extending outwardly from the body 111. The body 111 comprises a heat absorbing base 113 and four interconnecting sidewalls 114 integrally extending upwardly from the base 113. A first wick layer 116 is formed on an inner face of the body 111 by sintering metal power at the inner face. The first wick layer 116 covers allover the inner face, that is to say, the first wick layer 116 covers the base 113 and the sidewalls 114 of the tank 110. A second wick layer 156 is formed on an inner face of the plate 150 by tightly engaging a mesh sheet to the inner face. The first wick layer 116 is a sintered wick layer which is formed from sintering metal power. The second wick layer 156 is a meshed wick layer which is formed from a mesh. The first wick layer 116 on the sidewalls 114 extends toward the plate 150 to engage with the second wick layer 156. The first wick layer 116 and the second wick layer 156 are in porosity communication, therefore, liquid can flows between the first wick layer 116 and the second wick layer 156. The plate 150 has edges thereof air-tightly and liquid-tightly engaging with the flange 112 of the tank 110. Working fluid (not labeled) is filled in the chamber 180.

In the chamber 180 of the heat spreader 10, a plurality of artery meshes 170 are positioned between the base 113 and the plate 150. In this embodiment, there are four artery meshes 170 constructed in the heat sink. The artery mesh 170 is a flexible elongate hollow tube which is woven from a plurality of metal wires such as copper wires, aluminum wires, or stainless steel wires. Alternatively, the artery mesh 170 can also be woven from a plurality of fiber wires. A plurality of pores is defined in a wall (not labeled) of the artery mesh 170. The pores communicate the artery meshes 170 with the first wick layer 116 and the second wick layer 156 so that the working fluid can move between top and bottom portions of the heat spreader 10. That is, the working fluid can move between the second wick layer 156 and the first wick layer 116 via capillary forces generated by the artery meshes 170. The artery mesh 170 has an annular cross section and a channel (not labeled) defined in a middle portion of the artery mesh 170. In this embodiment, each artery mesh 170 is substantially L-shaped in profile. The four artery meshes 170 are spaced from each other and define a substantially X-shaped figure between the base 113 and the plate 150. Each artery mesh 170 has one end therefore located at a central portion (not labeled) of the base 113 and another end thereof extending to a corresponding lateral portion (not labeled) of the base 113.

Each fin 30 is made from metal sheet. The fin 30 is substantially L-shaped, and comprises a contacting portion thermally contacting the plate 150 of the heat spreader 10 and a heat dissipation portion extending remote from the plate 150.

In use, the base 113 of the tank 110 of the heat spreader 10 has the central portion thereof thermally contacting and absorbing heat from a heat-generating chip. The working fluid in the chamber 180 of the tank 110 is heated and vapored upwardly to reach the plate 150 of the heat spreader 10. At the plate 150, the vapored working fluid exchanges heat with the plate 150 and then is condensed to liquid. The liquid refluences to the base 113 via the second wick layer 156, the first wick layer 116 and the artery meshes 170. In the tank 110, the artery meshes 170 not only carry the working liquid from the second wick layer 156 to the first wick layer 116, but also carry the working liquid to a central portion of the base 113 from a lateral portion of the base 113. The vapored and condensed cycle of the working fluid in the tank 110 continues, the heat generated by the chip is transferred to the plate 150, and the heat in the plate 150 is dissipated by the fins 30 on the plate 150.

It is believed that the present invention and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.

Claims

1. A heat sink comprising:

a tank comprising a base for absorbing heat from a heat-generating member, and a first wick layer formed at an inner face of base;

a plate covering on the tank and hermetically engaging with the tank, the plate having a second wick layer formed at an inner face thereof;

a chamber being defined between the tank and the plate and containing working fluid therein; and

an artery mesh located in the chamber between the tank and the plate, the artery mesh being in porosity communication with the first wick layer and the second wick layer.

2. The heat sink of claim 1, wherein the first wick layer and the second wick layer are in porosity communication.

3. The heat sink of claim 1, wherein the tank comprises sidewalls extending from the base, the first wick layer covering inner faces of the sidewalls.

4. The heat sink of claim 3, wherein the first wick layer covers allover the base and the sidewalls.

5. The heat sink of claim 3, wherein the tank comprises a flange extending from the sidewalls, the flange engaging with the plate.

6. The heat sink of claim 5, wherein the flange parallels to the plate.

7. The heat sink of claim 1 further comprising a plurality of fins, wherein the fins thermally contacts the plate.

8. The heat sink of claim 7, wherein the each of the fins is L-shaped.

9. The heat sink of claim 8, wherein each of the fins comprises a contacting portion thermally contacting the plate and a heat dissipating portion extending remote from the plate.

10. The heat sink of claim 1, wherein the artery mesh has an end thereof located at a central portion of the base.

11. The heat sink of claim 10, wherein the artery mesh has another end thereof located at a lateral portion of the base.

12. The heat sink of claim 11, wherein the artery mesh is L-shaped.

13. The heat sink of claim 12 further comprising three additional artery meshes located in the chamber, wherein the artery meshes in the chamber define an X-shaped figure between the base and the plate.

14. The heat sink of claim 1, wherein the first wick layer is a sintered wick layer.

15. The heat sink of claim 1, wherein the second wick layer is a meshed wick layer.