HEAT TRANSFER DEVICE AND A MANUFACTURING METHOD THEREOF

Abstract

This disclosure is directed to a heat transfer device and a manufacturing method thereof. The method has steps of: providing a metal powder, firstly sintering the metal powder to form a plurality of sintered balls that each sintered ball has a plurality of first pores; provide a thermally conductive housing, the sintered balls are secondly sintered to form a capillary structure combined with the thermally conductive housing, wherein at least a part of an internal wall of the thermally conductive shell is cover with the sintered balls, a plurality of second pores are defined between the sintered balls, and each first pore is smaller than each second pore; filling a working fluid into the thermally conductive housing; and sealing the thermally conductive housing to define a sealed chamber in the thermally conductive housing, so that the capillary structure and the working fluid are contained in the sealed chamber.

Description

BACKGROUND OF THE INVENTION

Technical Field

This disclosure id directed to a phase change heat transfer device having a capillary structure made by secondary sintering and a manufacturing method thereof.

Description of Related Art

In general, a phase change heat transfer devices of related art such as a heat pipe or a vapor chamber has a hollow body made of metal and a working fluid which is easy to be boiled and is accommodated therein. The phase change heat transfer device has a portion which is contacted with a heat source, and heat is absorbed into the liquid working fluid located at this portion. The working fluid in liquid state at this portion is therefore vaporized and allowed to spread to the entire hollow body. The working fluid in gaseous state is condensed when moves away from the heat source, and the working fluid then flows back to the heat source. In order to accelerate the return flow of the working fluid, generally, the hollow body is provided with a capillary structure passing the heat source. The capillary structure is made of a metal powder sintered on an internal surface of the hollow body. The sintered metal powder has pores for adsorbing the working fluid in liquid state so that the working fluid is allowed to flow back to the heat source.

A capillary structure of related art is made of a metal powder by directly sintering to form pores densely distributed therein, and this leads to poor permeability to cause poor air permeability. Therefore, it is difficult to provide a pressure difference sufficient to drive the working fluid in liquid state which is adsorbed therein to flow smoothly, and it is also difficult to improve an efficiency of the return flow of the working fluid. The working fluid tends to dry out at the heat source.

In views of this, in order to solve the above disadvantage, the inventor studied related technology and provided a reasonable and effective solution in this disclosure.

SUMMARY OF THE INVENTION

This disclosure is directed to a phase change heat transfer device and manufacturing method thereof having a capillary structure made by twice sintering.

This disclosure is directed to a phase change heat transfer device having a thermal conductive shell, a capillary structure and a working fluid. The thermal conductive shell has a closed chamber. The capillary structure is disposed in the closed chamber, the capillary structure has a plurality of sintered balls, the thermal conductive shell has an internal surface having at least a portion covered with the sintered balls, each of the sintered balls is made of metal powder by sintering and each of the sintered balls has a plurality of first pores, and a plurality of second pores are defined between the sintered balls. Each of the first pores is smaller than each of the second pores. The working fluid is accommodated in the closed chamber.

In one embodiment, each of the sintered balls is made of a copper powder or an aluminum powder by sintering.

In one embodiment, the thermal conductive shell is made of copper of aluminum.

In one embodiment, the thermal conductive shell is tubular. The capillary structure is extended along a longitudinal direction of the thermal conductive shell.

In one embodiment, the thermal conductive sell is of a hollow plate shape. The capillary structure is disposed in the closed chamber corresponding to one side of the thermal conductive shell.

This disclosure is also directed to a heat transfer device manufacturing method having following steps: providing a metal powder and firstly sintering the metal powder into a plurality of sintered balls, each of the sintered balls has a plurality of first pores; providing a thermal conductive shell and secondary sintering the sintered balls into a capillary structure, wherein the capillary structure is combined with the thermal conductive shell, the thermal conductive shell has an internal surface having at least one portion covered with the sintered balls, and each of the first pores is smaller than each of the second pores; filling a working fluid into the thermal conductive shell; sealing the thermal conductive shell to define a closed chamber in the thermal conductive shell, so that the capillary structure and the working fluid are disposed in the closed chamber.

In one embodiment, the metal powder is a copper powder or an aluminum powder.

In one embodiment, the thermal conductive shell is made of copper or aluminum.

In one embodiment, the thermal conductive shell is tubular, and the capillary structure is extended along a longitudinal direction of the thermal conductive shell.

In one embodiment, the thermal conductive shell is of a hollow plate shape, and the capillary structure is disposed in the closed chamber corresponding to one side of the thermal conductive shell.

The manufacturing method of the heat transfer device according to this disclosure has the secondary sintering step, a specific amount of the metal powder 100 is firstly sintered in to the sintered ball 110 in the initial sintering step, and a specific amount of the sintered balls is then sintered onto the internal surface of the thermal conductive shell so as to form the capillary structure in the heat transfer device. Accordingly, the metal powder metal powder is densely stacked and large gaps are defined between the sintered balls. In other words, each of the first pores between the particles of the metal powder is smaller than each of the second pores between the sintered balls, so that the capillary structure of the heat transfer device according to this disclosure performs a good permeability and a good breathability.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the disclosure believed to be novel are set forth with particularity in the appended claims. The disclosure itself, however, may be best understood by reference to the following detailed description of the disclosure, which describes a number of exemplary embodiments of the disclosure, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a flowchart of a manufacturing method of a heat transfer device according to one embodiment of this disclosure.

FIG. 2 is a schematic view showing an initial sintering step of the manufacturing method of the heat transfer device according to one embodiment of this disclosure.

FIG. 3 is a schematic view showing a sintered ball of the heat transfer device according to one embodiment of this disclosure.

FIG. 4 is a schematic view showing a secondary sintering step of the manufacturing method of the heat transfer device according to one embodiment of this disclosure.

FIG. 5 is a schematic view showing a capillary structure of the heat transfer device according to one embodiment of this disclosure.

FIGS. 6 and 7 are schematic views showing the heat transfer device according to one embodiment of this disclosure.

FIGS. 8 and 10 are schematic views showing the heat transfer device according to another embodiment of this disclosure.

DETAILED DESCRIPTION

The technical contents of this disclosure will become apparent with the detailed description of embodiments accompanied with the illustration of related drawings as follows. It is intended that the embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive.

It should be understood that the orientations or positional relationships in this disclosure which are indicated by the terms such as “front side”, “rear side”, “left side”, “right side”, “front end”, “rear end”, “end”, “vertical”, “horizontal”, “vertical”, “top” and “bottom” are based on the orientations or positional relationships as shown in the drawings. These are only used for describing this disclosure and simplifying the description rather than indicating or implying that the device or element have a specific orientation or be constructed and operated in a specific orientation, and it should not be considered as limitations of the scopes of this disclosure.

The terms used herein without additional definition such as “substantially” and “approximately” are used to describe and illustrate small changes. When used in an event or situation, the term may include the precise moment at which the event or situation occurs, and a close approximation to moment the event or situation occurs. For example, when combined with a numerical value, the term may include a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.

Detailed descriptions and technical contents of this disclosure is described in the flowing paragraph with reference to the drawings. However, the drawings are attached only for illustration and are not intended to limit this disclosure.

According to an embodiment of this disclosure as shown in FIG. 1, a manufacturing method of a heat transfer device is provided, and the manufacturing method has steps described in following paragraphs.

According to FIGS. 1 and 2, firstly, a metal powder 100 is provided in an initial sintering step (step a). According to this embodiment, the metal powder 100 may be a copper powder or an aluminum powder. In this initial sintering step, the metal powder 100 is sintered into a plurality of sintered balls 110. As shown in FIG. 3, in each of the sintered ball 110, gaps are defined between the metal powders 100, and the gaps mentioned above are defined as a plurality of first pores 101 in the sintered ball 110.

According to FIGS. 1 and 2, in a secondary sintering step (step b) following the step a, a thermal conductive shell 200 is provided, and the thermal conductive shell 200 may be made of copper of aluminum according to this embodiment. Moreover, in this embodiment the heat transfer device is a heat pipe, and the thermal conductive shell 200 is therefore tubular, but scopes of this disclosure should not be limited to this. The sintered balls 110 are sintered in to a capillary structure 100a in this secondary sintering step, and the capillary structure 100a is sintered with the thermal conductive shell 200. According to FIG. 5, a plurality of second pores 102 are defined between the sintered balls 110 in the capillary structure 100a, and in the capillary structure 100a each of the first pore 101 is smaller than each of the second pore 102. According to this embodiment as shown in FIGS. 6 and 7, the capillary structure 100a is disposed to cooperate with a predetermined retuning route of the heat pipe to extended along a longitudinal direction of the thermal conductive shell 200. The thermal conductive shell 200 has an internal surface having at least one portion covered with the sintered ball 110, namely the capillary structure 100a covers the portion of the at least one portion of internal surface of the thermal conductive shell 200.

According to FIGS. 1 and 7, in a step c following the step b, a working fluid 300 is filled into the thermal conductive shell 200, and the working fluid 300 is a fluid with a low boiling point so as to be liquid at room temperature. The working fluid 300 may be water, alcohol, refrigerant, etc., but scopes of this disclosure should not be limited to this. In a step d following the step c, the thermal conductive shell 200 is sealed to defined a closed chamber 201 in the thermal conductive shell 200, so that the capillary structure 100a and the working fluid 300 are disposed together in the closed chamber 201.

According to FIGS. 8 and 9, the heat transfer device may be a vapor chamber, so that the thermal conductive shell 200 is of a hollow plate shape, and in the secondary sintering step (step b), the capillary structure 100a is disposed to cooperate with a predetermined retuning route of the vapor chamber to be in the closed chamber 201 corresponding to one side of the thermal conductive shell 200.

According to another embodiment of this disclosure as shown in FIGS. 5 to 7, a heat transfer device made by the manufacturing method mentioned above is provided. According to this embodiment, the heat transfer device is a heat pipe having a thermal conductive shell 200, a capillary structure 100a and a working fluid 300.

The thermal conductive shell 200 has a closed chamber 201, the thermal conductive shell 200 according to this embodiment may be made of copper or aluminum, and the thermal conductive shell 200 is tubular.

The capillary structure 100a is disposed in the closed chamber 201, according to this embodiment, each of the sintered balls 110 is made of a copper powder or an aluminum powder by sintering, and the capillary structure 100a is extended along a longitudinal direction of the thermal conductive shell 200. The capillary structure 100a has a plurality of sintered balls 110, the thermal conductive shell 200 has an internal surface having at least a portion covered with the sintered balls 110, each of the sintered balls 110 is made of a metal powder 100 by sintering and each of the sintered balls 110 has a plurality of first pores 101, and a plurality of second pores 102 are defined between the sintered balls 110, wherein each of the first pores 101 is smaller than each of the second pores 102. The working fluid 300 is accommodated in the closed chamber 201, the working fluid 300 is a fluid with a low boiling point so as to be liquid at room temperature. The working fluid 300 may be water, alcohol, refrigerant, etc., but scopes of this disclosure should not be limited to this.

The working fluid 300 is absorbed in the capillary structure 100a. The working fluid 300 is vaporized at an evaporating end 210 of the thermal conductive shell 200 when the evaporating end 210 is heated, and the working fluid 300 in gaseous state then flows in the closed chamber 201 to a condensing end 220 of the thermal conductive shell 200 along a longitudinal direction of the thermal conductive shell 200. The working fluid 300 in gaseous state is condensed at the condensing end 220 of the thermal conductive shell 200, then absorbed into the capillary structure 100a to return to the evaporating end 210 through the capillary structure 100a.

The manufacturing method of the heat transfer device according to this disclosure has the secondary sintering step, a specific amount of the metal powder 100 is firstly sintered in to the sintered ball 110 in the initial sintering step, and a specific amount of the sintered balls 110 is then sintered onto the internal surface of the thermal conductive shell 200 so as to form the capillary structure 100a in the heat transfer device. Accordingly, the metal powder metal powder 100 is densely stacked and large gaps are defined between the sintered balls 110. In other words, each of the first pores 101 between the particles of the metal powder 100 is smaller than each of the second pores 102 between the sintered balls 110, so that the capillary structure 100a of the heat transfer device according to this disclosure performs a good permeability and a good breathability. According to another embodiment of this disclosure as shown in FIGS. 8 to 10, another heat transfer device manufactured by the manufacturing method mentioned above is provided. In this embodiment, the heat transfer device is a vapor chamber having a thermal conductive shell 200, a capillary structure 100 a and a working fluid 300.

The thermal conductive shell 200 has a closed chamber 201, the thermal conductive shell 200 according to this embodiment may be made of copper or aluminum, the thermal conductive shell 200 is of a hollow plate shape and the thermal conductive shell 200 has an evaporating surface 230 at one side thereof. The capillary structure 100a is disposed in the closed chamber 201 corresponding to an evaporating surface 230 of the thermal conductive shell 200. The capillary structure 100a has a plurality of sintered balls 110, thermal conductive shell 200 has an internal surface having at least a portion covered with the sintered balls 110, each of the sintered balls 110 is made of a metal powder 100 by sintering and each of the sintered balls 110 has a plurality of first pores 101, a plurality of second pores 102 are defined between the sintered balls 110 second pore 102, wherein each of the first pores 101 is smaller than each of the second pores 102. The working fluid 300 is accommodated in the closed chamber 201, the working fluid 300 is a fluid with a low boiling point so as to be liquid at room temperature. The working fluid 300 may be water, alcohol, refrigerant, etc., but scopes of this disclosure should not be limited to this.

According to this embodiment, in an operation status of the heat transfer device, the working fluid 300 is adsorbed in the capillary structure 100a. When the evaporating surface 230 of the thermal conductive shell 200 is heated, the working fluid 300 in the capillary the structure 100a is vaporized, and the working fluid 300 in gaseous state spreads in the closed chamber 201. Then, the working fluid 300 in gaseous state leaves the evaporating surface 230 and is condensed, and the working fluid 300 is adsorbed into the capillary structure 100a. The working fluid 300 further flows back to the evaporating surface 230 through the capillary structure 100a.

While this disclosure has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of this disclosure set forth in the claims.

Claims

1. A heat transfer device, comprising: a thermal conductive shell, comprising a closed chamber;a capillary structure, arranged in the closed chamber, the capillary structure comprising a plurality of sintered balls, the thermal conductive shell comprising an interna surface comprising at least one portion covered with the sintered balls, each of the sintered balls being made of a metal powder by sintering, each of the sintered balls comprising a plurality of first pores therein, a plurality of second pores defined between the sintered balls, wherein each of the first pores is smaller than each of the second pores; anda working fluid, accommodated in the closed chamber.

2. The heat transfer device according to claim 1, wherein each of the sintered balls is made of a copper powder or an aluminum powder by sintering.

3. The heat transfer device according to claim 1, wherein the thermal conductive shell is made of copper or aluminum.

4. The heat transfer device according to claim 1, wherein the thermal conductive shell is tubular.

5. The heat transfer device according to claim 4, wherein the capillary structure is extended along a longitudinal direction of the thermal conductive shell.

6. The heat transfer device according to claim 1, wherein the thermal conductive sell is of a hollow plate shape.

7. The heat transfer device according to claim 6, wherein the capillary structure is disposed in the closed chamber corresponding to one side of the thermal conductive shell.

8. A manufacturing method of a heat transfer device, comprising: a) providing a metal powder and firstly sintering the metal powder into a plurality of sintered balls, wherein each of the sintered balls comprises a plurality of first pores;b) providing a thermal conductive shell and secondary sintering the sintered balls into a capillary structure, wherein the capillary structure is combined with the thermal conductive shell, the thermal conductive shell comprises an internal surface comprising at least one portion covered with the sintered balls, and each of the first pores is smaller than each of the second pores;c) filling a working fluid into the thermal conductive shell; andd) sealing the thermal conductive shell to define a closed chamber in the thermal conductive shell, so that the capillary structure and the working fluid are disposed in the closed chamber.

9. The manufacturing method according to claim 8, wherein the metal powder is a copper powder or an aluminum powder.

10. The manufacturing method according to claim 8, wherein the thermal conductive shell is made of copper or aluminum.

11. The manufacturing method according to claim 8, wherein the thermal conductive shell is tubular, and the capillary structure is extended along a longitudinal direction of the thermal conductive shell in the step b).

12. The manufacturing method according to claim 8, wherein the thermal conductive shell is of a hollow plate shape, the capillary structure is disposed in the closed chamber corresponding to one side of the thermal conductive shell in the step b).