KR102092307B1 - Vapor chamber - Google Patents

Abstract

Disclosed is a vapor chamber that is excellent in heat transfer and easy to manufacture. The vapor chamber includes a top plate on which a first fluid flow path is formed; A lower plate on which a second fluid flow path is formed; A filler material disposed along the edges of the upper plate and the lower plate to join the upper plate and the lower plate; And a graphite sheet disposed between the upper plate and the lower plate so as to contact the upper plate and the lower plate.

Description

Vapor chamber

The present invention relates to a vapor chamber (Vapor Chamber), and particularly relates to a vapor chamber that is excellent in heat transfer in the plane direction and easy to manufacture.

The vapor chamber is a device in which at least one portion is a substantially rectangular flat plate type device, and is a form of a heat pipe capable of efficiently transporting heat in a planar direction.

Conventional vapor chambers have a hollow container in which the upper member and the lower member are sealed by brazing using a filler material, the working fluid is contained in the container and the vacuum is maintained.

In the vapor chamber, there is a part that functions as an evaporation part and a part that functions as a condensation part. When the evaporation part is heated by a heat source, evaporation of the working fluid in the container occurs, and the working fluid in the gas phase condenses in the container ( Cold zone). In the low temperature region, the working fluid in the gas phase is cooled and condensed, and as a result, heat received by the working fluid in the evaporation part is discharged to the outside of the vapor chamber.

The condensed working fluid returns to the evaporator by a capillary phenomenon along a wick installed inside the container, and the working fluid returned to the evaporator evaporates again and moves to a low temperature region.

In this way, the vapor chamber transports heat using latent heat by repeating evaporation and condensation of the working fluid.

Existing vapor chambers are used, for example, for cooling of electronic devices, and there are limitations in quickly cooling heat of various structures or high temperatures in electronic devices in which thinning is performed. For example, in a portable electronic device represented by a smart phone, a large number of electronic components are accommodated in a limited space, and the vapor chamber applied thereto needs to maintain a thin thickness while having various shapes, and it is economical and easy to mass-produce. have.

In addition, since the high-performance AP operates while maintaining a high temperature, there is a limitation that the temperature of the AP must be sufficiently low in a short time.

In addition, there is a disadvantage that there is a difference in heat transfer or heat consumption depending on the posture or direction of the portable electronic device.

Accordingly, an object of the present invention is to provide a vapor chamber that can be usefully applied to an electronic device that is thinner and thinner while having various shapes.

Another object of the present invention is to provide a vapor chamber capable of rapidly dissipating heat by transferring heat absorbed from a heat source in a horizontal direction in a short time.

Another object of the present invention is to provide a vapor chamber that is easy to manufacture and economical.

The above object is a vapor chamber, the upper and lower plates of copper or copper alloy sheet; A filler material formed along edges of opposite surfaces of the upper plate and the lower plate, which are stacked to face each other, to join the upper plate and the lower plate; A fluid flow path formed on at least one of the opposite surfaces of the upper plate and the lower plate from the inside of the filler material; A working fluid filled in the fluid passage; And a graphite sheet positioned inside the filler material and disposed between opposite surfaces of the upper plate and the lower plate.

Preferably, each of the upper plate and the lower plate has at least one tip protruding integrally from the edge, and each tip is joined to the filler material except for the end to form an inlet for injecting the working fluid.

Preferably, the filler material is fused to the edge by brazing to seal between the upper and opposite surfaces of the lower plate.

Preferably, the fluid flow path may be formed between an emboss formed by etching or laser on opposite surfaces of any one of the upper plate and the lower plate.

Preferably, the size of the embo may be set differently based on the evaporation part, which is assumed to be a part where the heating element comes into contact.

Preferably, a support protrusion formed by the filler material is formed on a part of the embossing, and a through hole through which the support protrusion is fitted may be formed on the graphite sheet.

Preferably, both ends of the support protrusion may be joined to opposite surfaces of the upper plate and the lower plate, respectively.

Preferably, at least one of a copper wire mesh, a copper braided wire, or a copper knit wire may be further interposed between the upper plate and the opposite surfaces of the lower plate.

Preferably, the graphite sheet is a planar artificial graphite sheet, and may have a thermal conductivity in the horizontal direction of 1,000 W / m.K or more.

According to the present invention, the phase transition between the liquid phase and the gas phase of the working fluid is repeated, and heat recovered from the evaporation unit using latent heat is repeatedly transported to the cooling region (condensation unit).

In addition, the heat transferred from the heating element by the graphite sheet having good heat conduction in the width direction can be quickly transferred to other positions on the horizontal surface of the upper plate or the lower plate.

In addition, it is easy to transfer heat transfer evenly and quickly in various directions according to the mounting position of the graphite sheet by the graphite sheet having good heat conduction in the width direction.

In addition, since the graphite sheet is thin and flexible, it is easy to process into various shapes, and it is easy to insert into a thin vapor chamber, and it is easy to deform even by pressing, etc., to provide an economical and reliable vapor chamber.

1 is an exploded view showing a vapor chamber according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional view taken along line 2-2 of FIG. 1.
3 shows the inlet of the vapor chamber.

It should be noted that the technical terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. In addition, technical terms used in the present invention should be interpreted as meanings generally understood by a person having ordinary knowledge in the technical field to which the present invention belongs, unless defined otherwise. It should not be interpreted as the meaning of phosphorus or excessively reduced. In addition, when the technical term used in the present invention is a wrong technical term that does not accurately represent the spirit of the present invention, it should be understood as being replaced by a technical term that can be correctly understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted as defined in the dictionary or in context before and after, and should not be interpreted as an excessively reduced meaning.

1 is an exploded view showing a vapor chamber according to an embodiment of the present invention, Figure 2 is a partial cross-sectional view taken along line 2-2 of Figure 1;

The vapor chamber 100 includes a top plate 110 on which a fluid flow path 112 is formed, a bottom plate 120 on which a fluid flow path 122 is formed, and a filler material 130 formed along the edges of the top plate 110 and the bottom plate 120, And a graphite sheet 140 disposed between the upper plate 110 and the lower plate 120 so as to contact the upper plate 110 and the lower plate 120.

The upper plate 110 and the lower plate 120 may be made of copper or an alloy thereof having high thermal conductivity, but are not limited thereto, and may be made of a combination of aluminum.

The filler material 130 is formed to have a constant width along the edge of the top plate 110 or the bottom plate 120. For example, as in this embodiment, a metal material capable of performing a brazing operation, such as Ag / Cu, can be used. And the like.

Brazing can be performed in a vacuum in which heat and pressure are applied, or in a high temperature atmosphere furnace free of oxygen.

The filler material 130 makes contact with the upper plate 110 and the lower plate 120, respectively, thereby forming a hollow flat plate container in an airtight state, and a working fluid is discharged while non-condensing gas such as air is degassed inside the container. It is sealed.

The fluid passages 112 and 122 are formed by embosses 111 and 121 formed in a predetermined pattern on the upper plate 110 and the lower plate 120, that is, between the embossers 111 and 121 as shown in FIG. 2. The fluid passages 112 and 122 are formed by grooves having a square cross section. Here, the embosses 111 and 121 may be formed by, for example, etching.

The embosses 111 and 121 do not need to be formed in the same pattern, and thus the fluid flow paths 112 and 122 may not be symmetrical to each other as shown in FIG. 2 and may be formed to be offset at regular intervals.

As shown in FIG. 1, the circular embosses 111 and 121 are formed in a lattice shape, and as a result, the fluid flow paths 112 and 122 are entirely formed in a checkerboard shape and communicate with each other.

The width of the fluid flow paths 112 and 122 formed according to the size of the embossers 111 and 121 may vary, and the size of the embossers 111 and 121 is based on the evaporator 10 assumed to be a portion in which the heating element contacts. It can be set differently to the cooling unit along the longitudinal direction.

As shown in FIG. 2, some of the embosses 111 and 121 formed on the upper plate 110 or the lower plate 120 may have support protrusions 113 made of the same material as the filler material 130, but the filler material 130 It can be formed together when forming.

As will be described later, the support protrusion 113 is fitted into a through hole formed in the graphite sheet 140 interposed between the upper plate 110 and the lower plate 120, or a wick made of a copper wire mesh, a copper braided wire, or a copper knit wire ).

In addition to this, both ends of the support protrusion 113 are joined to the upper plate 110 and the lower plate 120 by brazing, so that the upper plate 110 and the lower plate 120 can be swollen.

On the upper plate 110 and the lower plate 120, tips 114 and 124 constituting an injection hole for injecting a working fluid are protruded.

3 shows the inlet of the vapor chamber.

In this embodiment, the tip 114 of the upper plate 110 and the tip 124 of the lower plate 120 are adhered to both edges by the filler material 130, and the filler material 130 is not formed at the end in the longitudinal direction, so that the injection port is not provided. 104 is formed, only the tip 114 of the upper plate 110 and the tip 124 of the lower plate 120 may protrude without the filler material 130.

To inject the working fluid through the inlet 104, as is well known, connect the vacuum pump to the inlet 104 to evacuate the inside to inject the working fluid into the chamber by the suction force of the vacuum, and then operate inside the chamber After leaving only a certain amount of fluid, the remaining working fluid is frozen using liquid nitrogen.

Thereafter, the inside of the pipe is evacuated again using a vacuum pump. At this time, the working fluid therein is frozen, so it does not come under the suction pressure of the vacuum pump, and only the space inside the pipe is evacuated.

Subsequently, as shown in FIG. 3 (b), the injection holes 104 are sealed by bonding to each other by spot welding, ultrasonic waves, or thermal welding by laser, and the chamber is in a vacuum state filled with a predetermined amount of working fluid.

According to the present invention, the graphite sheet 140 is disposed between the upper plate 110 and the lower plate 120 so as to contact the upper plate 110 and the lower plate 120.

The graphite sheet 140 has a thickness of, for example, about 10 to 70 μm, and a through hole 143 is formed at a position corresponding to the support protrusion 113 formed on the top plate 110 or the bottom plate 120, and the through hole is formed. 143 is fitted to the support projection 113, the graphite sheet 140 is fixed.

As is well known, since the graphite sheet 140 has a very good thermal conductivity in the horizontal direction, heat absorbed from the evaporation unit 10 can be quickly conducted to another location away from the horizontal surface.

In addition, the graphite sheet 140 is thin and flexible, so it is easy to process, and it is easy to deform by external force, so it can be applied to various types of vapor chambers, and it is easy to insert into the vapor chamber 100, which is economical. It is easy to manufacture a reliable vapor chamber 100.

In particular, the graphite sheet 140 is interposed with the upper plate 110 or the lower plate 120 in contact with each other, so that heat generated from the heating element contacting the upper plate 110 or the lower plate 120, for example, electronic components, is different from the horizontal surface. It can be quickly delivered to a location.

Preferably, the graphite sheet 140 is a planar artificial graphite sheet, and may have a thermal conductivity in the horizontal direction of 1,000 W / m.K or more, but is not limited thereto.

According to the vapor chamber having the above-described structure, a heating element such as an electronic component is disposed on a certain portion of the outer surface of the upper plate 110 or the lower plate 120, and the heating element is directly contacted or adhered through a thermally conductive adhesive or is in close proximity. Can be arranged.

An evaporator 10 is formed in a corresponding portion of the upper plate 110 or the lower plate 120 corresponding to the heating element, and when the working fluid is evaporated in this portion, the working fluid of the gas phase is diffused along the fluid passages 112 and 122. . Along with this, when heat generated from the heating element is transferred to the graphite sheet 140 through the upper plate 110 or the lower plate 120, the graphite sheet 140 moves to another location on the horizontal surface of the upper plate 110 or the lower plate 120. It is delivered quickly.

As the working fluid in the gas phase moves away from the evaporator 10, heat is taken away and condensed. This condensation phenomenon occurs particularly remarkably at the end far from the evaporator 10.

When the working fluid is condensed, the liquid working fluid returns to the vicinity of the evaporator 10 along the fluid passages 112 and 122, and absorbs heat from the heating element again.

As described above, the vapor chamber 100 of the present invention repeats the phase transition between the liquid phase and the gas phase of the working fluid, and repeats the heat recovered from the evaporation unit 10 using latent heat to the cooling region (condensation unit). I can transport it.

In addition, the heat transferred from the heating element by the graphite sheet 140 through the evaporator 10 can be quickly transferred to another position on the horizontal surface of the upper plate 110 or the lower plate 120.

In the above embodiment, a vapor chamber constituting a hollow flat container is taken as an example, but the present invention is equally applied to a heat pipe.

Specifically, a fluid flow path is formed on the inner surface of the sealing body made of copper or a copper alloy, a working fluid is filled, a graphite sheet is accommodated in the sealing body in response to the fluid flow path, and the graphite sheet contacts the inner surface of the sealing body.

The heat pipe may be formed in a circular cross section or pressed flat so that a corresponding portion of the sealing body in contact with the heating element maintains a flat surface.

In the above, although the description has been mainly focused on the embodiment of the present invention, it is needless to say that various changes can be made at the level of those skilled in the art. Therefore, the scope of the present invention can not be interpreted limited to the above-described embodiment, it should be interpreted by the claims described below.

100: Vapor chamber
110: top
112, 122: fluid flow path
120: bottom
130: Yongjae
140: graphite sheet

Claims (13)

As a vapor chamber,
Upper and lower plates of copper or copper alloy sheet;
A filler material disposed along the edges of the upper plate and the lower plate to join the upper plate and the lower plate;
A fluid flow path formed between embosses formed on at least one of the opposite surfaces of the upper plate and the lower plate from the inside of the filler material;
A working fluid filled in the fluid passage; And
Support protrusions formed by the filler material, both ends of which are joined to opposite surfaces of the upper plate and the lower plate to prevent the upper plate and the lower plate from swelling; And
It includes a graphite sheet disposed between the upper plate and the lower plate to contact the upper plate and the lower plate,
A vapor chamber, characterized in that the support sheet is fitted into the through hole of the graphite sheet to fix the graphite sheet. In claim 1,
The size of the embosser is a vapor chamber, characterized in that it is set differently to the cooling part along the longitudinal direction based on the evaporation part assumed to be the part where the heating element contacts. In claim 1,
Each of the upper plate and the lower plate has at least one tip protruding integrally from the edge, and each tip is bonded to the filler material except for an end portion to form an inlet for injecting the working fluid. .
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