WO2024010314A1

WO2024010314A1 - Vacuum chamber having multilayer graphite stack

Info

Publication number: WO2024010314A1
Application number: PCT/KR2023/009355
Authority: WO
Inventors: 주학식; 주세현
Original assignee: 주학식; 주세현
Priority date: 2022-07-04
Filing date: 2023-07-03
Publication date: 2024-01-11
Also published as: KR20240004111A; KR20240004112A

Abstract

The present invention provides a vacuum chamber having a multilayer graphite stack. The objective of the present invention is to provide a vacuum chamber having a multilayer graphite stack, the chamber having a graphite unit, formed by stacking a plurality of graphite sheets, that is vacuum-accommodated in a chamber housing, thereby maximizing thermal diffusion efficiency so as to ensure excellent cooling performance, and decreasing heat transfer in the vertical direction so that heat can be uniformly diffused in the horizontal direction.

Description

Vacuum chamber with multi-layer graphite laminate

The present invention relates to a vacuum chamber having a multi-layer graphite laminate. More specifically, the present invention relates to a vacuum chamber having a multi-layer graphite laminate. More specifically, a plurality of graphite sheets with high thermal conductivity are stacked in a multi-layer structure, and these are placed inside a chamber housing that forms a vacuum receiving space, so that each By keeping the graphite sheets closely attached to each other, the thermal diffusion rate is improved, and heat transfer in the vertical direction is blocked on the upper side of the stacked graphite sheets, allowing the heat transferred from the heat source to quickly diffuse horizontally, leading to excellent thermal insulation. It relates to a vacuum chamber having a multi-layer graphite laminate that can guarantee cooling performance.

Recently, as the spread of various cutting-edge electronic devices, such as high-performance portable wireless information terminals and home appliances operated in conjunction with wired and wireless communication networks, has rapidly increased, the trend toward high integration of electronic devices used in these devices and widening frequencies has led to electromagnetic waves. The need for heat dissipation from devices and sources of heat is increasing.

For example, in the case of the MSM (Mobile Solution Module) chip of a mobile phone, the temperature rise is so large that the maximum temperature of the chip exceeds 80℃ when operated in full mode. There is no space to install a heat sink in slim digital devices such as mobile phones. Therefore, the most effective method is to use a heat diffusion mechanism to spread the temperature of the hot spot to the entire space to lower the average temperature. As a result, it has high thermal conductivity in the horizontal direction and is flexible and adhesive like existing adhesive films. There is a need to develop technology to manufacture it in a sheet form with excellent properties. As can be seen from this, there is an urgent need to develop effective heat dissipation technology as the performance of electrical appliances increases.

As a prior art, a graphite heat dissipation sheet coated with a thermally conductive adhesive has been proposed through Korean Patent No. 10-0755014, which is manufactured by mixing polydimethylsiloxane, silicone resin, and thermally conductive pillar on one side of the graphite heat dissipation sheet. By applying a thermally conductive adhesive, it is easy to adhere to the display product and improve thermal conductivity. However, not only does it have the disadvantage of poor heat dissipation performance as the graphite layer is easily cracked or damaged due to bending deformation or external force, but it is also relatively expensive. It is not only technically difficult to manufacture for electronic devices such as large-scale displays, but also requires dedicated facilities and has poor mass production, so it is being used for heat dissipation purposes in relatively low-specification electronic devices.

Another prior art is a vapor chamber manufactured with a flat device or a circular heat pipe type device, and the 'vapor chamber' of Korean Patent Publication No. 10-2021-0122572 has been proposed as the prior art. , claim 1 includes a pair of containers arranged opposite each other; a pair of wicks disposed inside the pair of containers; and a spacer disposed inside the pair of wicks; It includes, wherein the container, the wick, and the spacer are made of a low dielectric constant polymer material having a dielectric constant in the range of 1 to 3.5, and the working fluid provided in the wick transfers heat supplied to one of the containers to the other one of the containers. A vapor chamber that changes phase for delivery to a container is disclosed.

However, not only is it difficult to enlarge the vapor chamber according to the prior art, but the manufacturing process is difficult, making economical mass production difficult. In particular, the application target is limited due to the disadvantage of having to use it in combination with a heat dissipation sheet for the purpose of dispersing heat in electronic devices. There was a problem.

The present invention was created to solve the problems of the prior art as described above. The purpose of the present invention is to prepare a graphite unit made by laminating two or more graphite sheets with excellent thermal conductivity inside a chamber housing, and to provide a graphite unit for the chamber housing. It is placed inside the unit and then sealed by applying vacuum pressure. The graphite unit, which is made up of multi-layer graphite sheets, can quickly and efficiently diffuse the heat transferred from the heat source by the action of its arrangement structure, resulting in excellent cooling performance. The aim is to provide a vacuum chamber with a multi-layer graphite laminate that can provide guaranteed stability.

In addition, the present invention additionally configures an element to suppress heat transfer on the upper side of the stacked graphite unit, thereby suppressing the rapid diffusion and transfer of heat transferred from the heat source in the vertical direction from the graphite unit, thereby achieving uniform heat diffusion characteristics in the horizontal direction. The aim is to provide a vacuum chamber having a multi-layer graphite laminate capable of having a.

A vacuum chamber having a multi-layer graphite laminate according to another preferred embodiment of the present invention for realizing the above object is made of a metal material by joining the upper cover and the lower cover to form an accommodating space inside where vacuum pressure acts. chamber housing; A graphite unit made by stacking a plurality of graphite sheets with different thicknesses inside the chamber housing and maintaining the top and bottom closely attached to each other by vacuum pressure acting within the chamber housing. Do it as

As a preferred feature of the present invention, the graphite unit is composed of stacking 2 to 20 graphite sheets having different thicknesses, and each graphite sheet is provided with a thickness of 5㎛ to 300㎛.

As another preferred feature of the present invention, the chamber housing is provided with a lower cover whose edge protrudes upward as the graphite unit is raised, and a lower cover with a shape corresponding to the upper side of the lower cover to form a receiving space together with the lower cover. A side wall unit seals the internal receiving space by joining the cover and the edges of the upper cover and lower cover, and the receiving space is divided into upper and lower parts to form a space for accommodating a plurality of graphite units, the edge of which is inside the side wall part. It consists of one or more vertical heat diffusion plates made of metal plates that are connected to the wall and transmit heat.

As another preferred feature of the present invention, the graphite unit is an upwardly increasing thickness type graphite unit in which graphite sheets of increased thickness are sequentially stacked on the upper side of the graphite sheet located at the lowermost side. Or, a downward thickness increasing type graphite unit that sequentially stacks graphite sheets of reduced thickness on the upper side based on the graphite sheet located at the bottom;, or a random graphite unit that randomly stacks graphite sheets of different thicknesses. A vacuum chamber having a multi-layer graphite laminate, characterized in that:

A vacuum chamber having a multi-layer graphite laminate according to another preferred embodiment of the present invention for realizing the above object has a lower cover made of a metal material provided in the form of a plate and disposed opposite to the upper side thereof, and has a lower cover with respect to the lower cover. A chamber housing consisting of an upper cover made of a metal material with thermal conductivity to block heat transmitted in the vertical direction, and a side wall portion that joins the edges of the lower cover and the upper cover to form an accommodating space where vacuum pressure is applied; Thermal diffusion is induced in the horizontal direction by the upper cover, which is provided in the receiving space and has low thermal conductivity, and 2 to 20 graphite sheets with a thickness of 5㎛ ~ 300㎛ are stacked and each graphite sheet is brought into close contact with each other by vacuum pressure. It is characterized by being composed of a graphite unit provided in the state.

A vacuum chamber having a multi-layer graphite laminate according to another preferred embodiment of the present invention includes an upper cover provided with a heat shear element for blocking heat transfer in the vertical direction, a lower cover disposed oppositely below the upper cover, and the upper cover A chamber housing consisting of a side wall portion that forms a vacuum accommodation space therein by protruding and joining one or both of the edges of the lower cover and the lower cover; It is characterized by being composed of a graphite unit, which is made by stacking a plurality of graphite sheets in the receiving space, and each graphite sheet is provided in close contact with each other by vacuum pressure.

As a preferred feature of the present invention, according to one of the preceding claims, the graphite unit is an upwardly increasing thickness type graphite unit in which graphite sheets of increased thickness are sequentially stacked on the upper side of the lowermost graphite sheet as a reference; . Or, a downward thickness increasing type graphite unit that sequentially stacks graphite sheets of reduced thickness on the upper side based on the graphite sheet located at the bottom;, or a random graphite unit that randomly stacks graphite sheets of different thicknesses. There is something about being one.

As another preferred feature of the present invention, the blocking element is an insulating film formed by coating a synthetic resin material or attaching a sheet of synthetic resin material to the upper or lower surface of the upper cover to reduce heat transfer in the vertical direction; or It is one of a porous insulating sheet made of metal or synthetic resin that is provided to reduce heat transfer in the vertical direction between the lower surface of the upper cover and the upper surface of the graphite unit.

As another preferred feature of the present invention, the chamber housing divides the receiving space into upper and lower sections to form a space for accommodating a plurality of graphite units, and the edge of the chamber is a metal plate connected to the inner wall of the side wall to transmit heat. It consists of one or more vertical heat diffusion plates.

In a vacuum chamber having a multi-layer graphite laminate according to an embodiment of the present invention, heat transferred from the outside is provided inside the chamber housing made of copper or an alloy material containing copper or a known metal material with excellent thermal conductivity. The effect of ensuring improved performance in heat dissipation and heat dissipation for heat generated from electronic devices as heat diffusion is achieved quickly and efficiently through a graphite unit consisting of a plurality of graphite sheets closely attached to each other by vacuum pressure. I'm looking forward to it.

In addition, the present invention has a simple structure and can be manufactured in a large area, so not only can it be economically mass produced, but it can also be easily applied to electronic devices with a large heating surface to ensure optimal performance. As a result, it has the effect of increasing the product value of electronic products using it.

In addition, the present invention can secure excellent heat dissipation characteristics by using sintered metal or graphite with excellent thermal conductivity as the multi-layer graphite layer, so it is expected to have the effect of ensuring high heat dissipation according to the high performance of electronic devices.

In particular, in the present invention, the upper cover constituting the chamber housing is made of a metal material with a relatively low thermal conductivity compared to the lower cover, so that the heat transferred from the heat source to the graphite unit is not spread uniformly in the horizontal direction but rapidly spreads in the vertical direction. By suppressing transmission, the graphite unit provided in the form of a plate is encouraged to spread evenly in the area direction, that is, in the horizontal direction, thereby achieving uniform heat dissipation performance for electronic components such as large-area displays such as smart and tablet PCs. There is an advantage that can be provided.

In addition, in the present invention, the entire chamber housing is molded from a metal material such as copper with excellent thermal conductivity, and an insulating film is formed on the upper or lower surface of the upper cover constituting the chamber housing to reduce heat transfer in the vertical direction, or the upper cover of the upper cover is formed. By providing a porous insulation sheet between the lower surface and the upper surface of the graphite unit, heat transfer in the vertical direction is blocked, allowing the heat transferred to the graphite unit to be transferred evenly in the horizontal direction. As a result, it can be used in devices such as smartphones and tablet PCs. When applied to a display, it is possible to secure uniform heat dissipation characteristics over the entire large area rather than local heat dissipation, so it is expected to have the effect of guaranteeing the performance of electronic devices using it.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, terms or words used in this specification and claims should not be construed in their usual, dictionary meaning, and the inventor may appropriately define the concept of the term in order to explain his or her invention in the best way. It must be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that

1 is a cross-sectional view illustrating the configuration of a vacuum chamber having a multilayer graphite laminate according to a preferred embodiment of the present invention;

Figure 2 is a partially cut away perspective view for explaining the internal structure of the vacuum chamber having the multi-layer graphite laminate shown in Figure 1;

Figure 3 is a cross-sectional view for explaining the internal structure of a vacuum chamber having a multi-layer graphite laminate according to another embodiment of the present invention;

Figure 4 is a heat conduction comparison diagram between a vacuum chamber having a multi-layer graphite laminate according to the present invention and the prior art;

Figure 5 is a thermal image comparison diagram of a single-layer graphite and a multi-layer graphite laminate structure in a vacuum chamber having a multi-layer graphite laminate according to the present invention.

Figure 6 is a schematic diagram showing test conditions for comparing performance with existing products in a vacuum chamber having a multi-layer graphite laminate according to the present invention.

Figure 7 is a graph showing the GaP temperature change at points P0 to P2 over time under the conditions of Figure 6 in a vacuum chamber having a multi-layer graphite laminate according to the present invention;

Figure 8 is a graph showing the change in heat source temperature over time under the conditions of Figure 6 in a vacuum chamber having a multi-layer graphite laminate according to the present invention;

9 and 11 are schematic diagrams showing several examples of graphite units in a vacuum chamber having a multi-layer graphite laminate according to the present invention.

12 and 15 are views showing several embodiments of chamber housing in a vacuum chamber with a multilayer graphite laminate according to the present invention.

1: Vacuum chamber with multi-layer graphite laminate

10: Chamber housing 11: Upper cover

13: lower cover 15: side wall part

30: graphite unit 31: graphite sheet

50: insulation film 55: porous insulation sheet

Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the attached drawings. However, it is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. In this application, terms such as “include” or “have” are intended to designate the presence of features, steps, operations, components, parts, or combinations thereof described in the specification, but not one or more other features, steps, or operations. , it should be understood that it does not exclude in advance the possibility of the existence or addition of components, parts, or combinations thereof. In other words, throughout the specification, when a part is said to “include” a certain component, this means that it does not exclude other components but may further include other components, unless specifically stated to the contrary.

Additionally, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

Here, repetitive descriptions and detailed descriptions of known functions and configurations that may unnecessarily obscure the gist of the present invention are omitted in order to not obscure the gist of the present invention. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Therefore, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

Hereinafter, the configuration of the present invention will be briefly described according to the attached drawings.

FIG. 1 is a cross-sectional view illustrating the configuration of a vacuum chamber having a multi-layer graphite laminate according to a preferred embodiment of the present invention, and FIG. 2 is a perspective view cut from the bottom illustrating the internal configuration of FIG. 1 .

In the drawing, a chamber housing 10 made of a metal material with excellent thermal conductivity such as copper is formed to form an accommodating space inside which vacuum pressure acts, and a plurality of graphite sheets are stacked inside the chamber housing 10. A vacuum chamber (1) is shown having a multi-layer graphite laminate consisting of graphite units (30) kept closely attached to each other by the vacuum pressure acting within the chamber housing (10).

Figure 3 is a cross-sectional view for explaining the internal structure of a vacuum chamber having a multi-layer graphite laminate according to another embodiment of the present invention.

In the drawing, there is shown a chamber housing 10 made of a metal material that provides an empty receiving space (not shown) for vacuum pressure to act inside, and a plurality of graphite sheets 31 inside the chamber housing 10. Graphite units 30, which are made by stacking two or more units and remain closely attached to each other by the vacuum pressure acting on the inside of the chamber housing 10, and the inner space of the chamber housing 10, A vacuum chamber having a multi-layer graphite laminate made of a vertical heat diffusion plate (20) made of a metal plate that is divided into lower sections and whose edge is connected to one side of the chamber housing (10) to receive heat and transmit it to the upper and lower sides. (1) is shown.

Figure 4 shows a heat conduction comparison diagram between a vacuum chamber having a multi-layer graphite laminate according to the present invention and the prior art.

In the drawing, on the left, several graphite sheets are stacked using a conventional binder (adhesive or double-sided adhesive tape), and on the right, several graphite sheets are attached to each other using vacuum pressure without using a binder according to the present invention. The graphite sheet used in both cases was used to have a thickness of 0.025 mm, and the thickness of the copper layer forming the chamber housing was 0.020 mm in the prior art and 0.025 mm in the present invention, and experimental data on heat conduction and heat diffusion were obtained. got it

As confirmed through this, the binder bonded comparative product had a heat conduction of 302 W/mK and a heat diffusion of 188.9 mm ² /s, while the product according to the present invention had a heat conduction of 951.3 W/mK and a heat diffusion of 594.6 mm. It was confirmed to be ² /s. In other words, it can be seen that the heat conduction of the conventional comparative product using a binder drops sharply due to the thermal resistance generated from the binder.

Figure 5 is a comparative thermal image diagram of a single-layer graphite and a multi-layer graphite laminate structure in a vacuum chamber having a multi-layer graphite laminate according to the present invention.

In the drawing, the left side is a photograph of a thermal image of a vacuum chamber with a single-layer graphite sheet interposed therebetween, and the right side is a photograph of a thermal image of a vacuum chamber formed by stacking multi-layer graphite sheets according to the present invention, and the GAP temperature The lower the value, the better the heat transfer (diffusion), and it was confirmed that a laminate made of multi-layer graphite sheets with the same thickness was relatively better than a configuration using single-layer graphite sheets.

Figure 6 is a schematic diagram for comparing the performance of a vacuum chamber with a multi-layer graphite laminate according to the present invention with existing products. In the figure, the left side (A) is a diagram for measuring the temperature characteristics of a mobile phone (electronic device) to which the present invention is applied. The conditions for measuring the temperature characteristics of a mobile phone (electronic device) to which the prior art is applied are shown on the left, with P0, P1, P2, and P3 being the heat source (heater) of the electronic device; such as an electronic chip, etc. ) indicates the point for measuring temperature characteristics.

In addition, in the drawing, the product standard of the present invention and the prior art is 130mm × 70mm × 0.1mm, the power consumption of the heater is 11.5W (5.5V, 2A), and the temperature of the chamber is 25 degrees (± 0.5). The test was conducted under conditions.

Figure 7 is a graph showing the GaP temperature change at points P0 to P2 over time under the conditions of Figure 6 in a vacuum chamber having a multi-layer graphite laminate according to the present invention.

In the drawing, the graph line located at the top shows the GaP temperature change at points P0 to P2 for existing products, and the graph line located at the bottom of the drawing shows the GaP temperature change at points P0 to P2 for the product according to the present invention. It can be seen that the temperature difference of the product of the present invention is small compared to the existing product. This can be interpreted as ensuring stable heat dissipation performance over time.

Figure 8 is a graph showing the change in heat source temperature over time under the conditions of Figure 6 in a vacuum chamber having a multi-layer graphite laminate according to the present invention.

In the drawing, the graph line located on the upper side is a measurement of the heat source temperature for the existing product, and the lower graph line in the drawing is a measurement of the heat source temperature for the product of the present invention. As confirmed through this, the product of the present invention is It can be seen that the heat dissipation performance for the heat source is guaranteed within a relatively stable range regardless of changes.

9 and 11 are diagrams showing several examples of graphite units in a vacuum chamber having a multi-layer graphite laminate according to the present invention.

Figure 9 shows an upwardly increasing thickness type graphite unit 31a having a stacked form in which the thickness of the graphite sheets stacked on the upper side of the graphite sheet 31a1 located at the lowermost side is gradually increased.

Figure 10 shows a downward-thickness-increasing graphite unit 31b having a stacked form in which the thickness of the graphite sheets stacked on the upper side of the graphite sheet 31b1 located at the lowermost side is gradually reduced.

FIG. 11 shows a random graphite unit 31c in which a plurality of graphite sheets having different thicknesses are randomly stacked.

12 and 14 are views showing several examples of chamber housing in a vacuum chamber having a multilayer graphite laminate according to the present invention.

In the embodiment shown in FIG. 12, the upper cover 11 and lower cover 13 constituting the chamber housing 10 are molded and joined from different metal materials, and the upper cover 11 is formed by lower cover 13. ) shows a configuration that is molded from a metal material with low thermal conductivity.

The embodiment shown in FIG. 13 shows a configuration in which an insulating film 50 is provided by coating a synthetic resin material or attaching a synthetic resin sheet to the upper surface of the upper cover 11 constituting the chamber housing 10, At this time, the insulation film 50 is an element to prevent local heat dissipation from occurring due to rapid transfer of heat from the heat source to the graphite unit 30 in the vertical direction, and reduces the heat dissipation characteristics in the vertical direction, resulting in It is an element to ensure that heat is spread uniformly in the horizontal direction of the graphite unit 30.

The embodiment shown in FIG. 14 shows a configuration in which an insulating film 50 is provided on the lower surface of the upper cover 11 constituting the chamber housing 10. In this case, the insulating film 50 is made of a synthetic resin material with insulating properties. It is formed by coating it to have a certain thickness or attaching a synthetic resin material and performs the same function as in Figure 13.

The embodiment shown in FIG. 15 is a porous material made of metal or synthetic resin to reduce heat transfer in the vertical direction between the lower surface of the upper cover 11 constituting the chamber housing 10 and the upper surface of the graphite unit 30. This shows the porous insulation sheet 55, where the porous insulation sheet 55 performs the same role as the insulation film 50 described above. This porous insulation sheet 55 has physical properties that enable volume reduction by external force as it forms pores, and has the effect of reducing heat transfer through the pores.

A vacuum chamber having a multi-layer graphite laminate according to the present invention will be described with reference to the above drawings as follows.

The present invention is to provide a vacuum chamber having a multi-layer graphite laminate that contacts the heating surface of an electronic device with heat generating characteristics and performs a heat dissipation function, comprising a chamber housing 10 largely forming an external body, and this chamber housing ( It consists of a graphite unit 30 provided inside 10).

The chamber housing 10 is made of copper, a copper alloy containing copper, or a known metal material with excellent thermal conductivity, and largely consists of an upper cover 11, a lower cover 13, and a side wall portion 15.

The upper cover 11 is provided in the form of a plate made of copper or metal, and its lower surface is provided so that the upper surface of the graphite unit 30 is in contact with it. This upper cover 11 is preferably provided so that an edge portion protrudes downward to form a side wall portion 15, which will be described later.

The lower cover 13 is spaced apart from the upper cover 11 to form an accommodating space 10s therein. Like the upper cover 11, the lower cover 13 is made of copper or thermally conductive material. It is molded from an excellent metal material, and the lower surface of the graphite unit 30 is raised in close contact with the upper surface.

This lower cover 13 is provided in a shape corresponding to the upper cover 11, and the edge portion protrudes upward and comes into contact with the protruding edge portion of the upper cover 11 to form a side wall portion 15, which will be described later. It is desirable to form

The side wall portion 15 is formed by protruding the edges of the upper cover 11 and the lower cover 13 and joining them with welding or adhesive, and is formed inside the upper cover 11 and the lower cover 13. A receiving space (10s) is formed in which the graphite unit (30) on which pneumatic pressure acts is placed.

This side wall portion 15 is formed by placing a strip-shaped length member made of copper or metal between the upper cover 11 and the lower cover 13 and then integrally joining it by welding, or It would also be possible to bend the edge of the lower cover 13 in a vertical direction and weld the vertically bent end to the lower cover 13 or upper cover 11 to form an integrated structure.

Meanwhile, the chamber housing 10 of the present invention must be preceded by a process of placing the graphite unit 30 therein before integrating the side wall portion 15 with the upper cover 11 and lower cover 13. .

The graphite unit 30 is constructed by stacking a plurality of graphite sheets 31. In the present invention, as a preferred embodiment, it is proposed that 2 to 10 graphite sheets 31 are stacked, and each graphite sheet 31 is It is desirable to have a thickness of 5㎛ ~ 300㎛.

It is proposed that each graphite sheet 31 constituting the graphite unit 30 has a thickness of 5 μm to 300 μm.

This means that if the thickness of the graphite sheet 31 is less than 5㎛, damage due to cracks occurs in the graphite sheet 31 when vacuum pressure is applied to the inside of the chamber housing 10, and these cracks ultimately affect the heat dissipation characteristics. It causes problems that make it defective. It was confirmed that if the thickness of each graphite sheet 31 exceeds 300 ㎛, there is no effect of increasing heat dissipation characteristics, and rather, it causes a problem of poor heat transfer characteristics.

In the present invention, it is proposed to stack 2 to 10 graphite sheets 31 constituting the graphite unit 30.

In particular, it was confirmed that when two or more graphite sheets 31 are stacked, the heat diffusion rate is good and has excellent heat dissipation characteristics, as shown in FIG. 5, compared to a single graphite sheet 31.

That is, referring to FIG. 5, the left side of the drawing is a photograph of a thermal image of a vacuum chamber interposed with a single-layer graphite sheet, and the right side is a thermal image of a vacuum chamber formed by stacking multi-layer graphite sheets according to the present invention. As a photo taken, it was confirmed that the lower the GAP temperature, the better the heat transfer (diffusion), and that the laminate made of multi-layer graphite sheets with the same thickness was relatively better than the configuration using single-layer graphite sheets.

In addition, when comparing the heat conduction of a structure in which multi-layer graphite sheets are laminated using a binder (adhesive or double-sided tape) and a structure in which several graphite sheets are attached and laminated using vacuum pressure without the use of a binder as in the present invention, the binder It was confirmed that loss due to thermal resistance occurred when was used.

Explaining this with reference to FIG. 4, the left side of the drawing is a configuration in which several graphite sheets are stacked using a binder (adhesive or double-sided adhesive tape) according to the conventional method, and the right side is a configuration in which vacuum pressure is applied without the use of a binder according to the present invention. It is used to attach several graphite sheets to each other.

The graphite sheet used in these binder-type existing products and the vacuum pressure attachment-type product of the present invention was both used to have a thickness of 0.025 mm, and the thickness of the copper layer forming the chamber housing was 0.020 mm in the prior art, and in the present invention Experimental data on heat conduction and heat diffusion were obtained using 0.025mm.

In the vacuum chamber having the multi-layer graphite laminate according to the present embodiment configured as described above, when the metal chamber housing 10 is in close contact with the heating surface of the electronic device and heat is conducted, the vacuum chamber 10 is generated inside the chamber housing 10. Cooling by reverse diffusion occurs by the graphite unit 30, which is made up of a plurality of graphite sheets 31 that are closely attached to each other by pneumatic pressure.

In particular, the graphite unit 30 stacks a plurality of graphite sheets 31 and applies vacuum pressure to the inside of the chamber housing 10 containing the graphite sheets 31, thereby creating pressure between the graphite sheets 31. By eliminating the gap, heat transfer efficiency can be maximized. That is, when multiple graphite sheets 31 are stacked and an adhesive is used between each graphite sheet 31, the heat dissipation performance is lowered as the heat transfer property by the adhesive decreases. However, the present invention is a method of stacking a plurality of graphite sheets 31. Since it is a method of bringing the sheets (31) into close contact with each other using vacuum pressure without any inclusions between them, the heat dissipation characteristics of the graphite sheet (31) can be fully guaranteed.

Meanwhile, the present invention proposes an embodiment as shown in FIGS. 9 to 11 in configuring the graphite unit 30 in consideration of heat transfer efficiency.

First, the graphite unit 30 shown in the embodiment of FIG. 9 is an upward-thickness-increasing graphite type in which graphite sheets of gradually increased thickness are stacked and arranged upwardly based on the graphite sheet 31a1 located at the bottom. It is suggested that it be provided as a unit.

That is, referring to the drawing, the first graphite sheet (31a1) placed at the bottom has the thinnest thickness, and the second graphite sheet (31a2) placed on top has a relatively increased thickness with respect to the first graphite sheet. And the third graphite sheet 31a3 placed on the upper side of the second graphite sheet 31a2 also has an increased thickness relative to the second graphite sheet, and the fourth graphite sheet placed on the upper side of the third graphite sheet 31a2 The third graphite sheet 31a4 also has a relatively increased thickness with respect to the third graphite sheet and is arranged in a stacked manner.

In the case of this upwardly increasing thickness graphite unit, the graphite sheet placed closest to the heat source is thin, so it quickly receives heat transferred from the heat source and performs a heat diffusion function.

The graphite unit shown in the example of FIG. 10 represents a downward thickness increasing type graphite unit 31b in which the thickness of the graphite sheet gradually increases as it progresses from the top to the bottom. When explained with reference to the drawing, at the bottom The first graphite sheet (31b1) disposed is the thickest, and the second graphite sheet (31b2) placed on top is laminated with a thickness that is reduced relative to the first graphite sheet, and the second graphite sheet (31b2) is laminated The third graphite sheet (31b3) placed on the upper side of the sheet (31b2) is also laminated with a thickness relatively reduced with respect to the second graphite sheet, and the fourth graphite sheet (31b4) placed on the upper side of the third graphite sheet. Again, the third graphite sheet has a relatively reduced thickness and is stacked.

This downward-thickness-increasing graphite unit performs heat dissipation by quickly transferring heat through a heat sink (not shown) provided on the upper surface of the chamber housing.

The graphite unit according to the embodiment of FIG. 11 is a randomly stacked arrangement of a plurality of graphite sheets 31 with various thicknesses, and its effect is improved performance in terms of thermal diffusion and conductivity compared to the embodiment of FIGS. 9 and 10. It may fall, but it can be applied and manufactured according to the orderer's request.

Hereinafter, a vacuum chamber having a multilayer graphite laminate according to another embodiment of the present invention will be described with reference to FIG. 3.

The vacuum chamber having a multi-layer graphite laminate according to this embodiment is substantially the same as the configuration of the embodiment described above. However, this embodiment has the feature of additionally forming a vertical heat diffusion plate 20 that divides the inner space of the chamber housing 10 into upper and lower sections to form a plurality of receiving spaces 10s.

To explain this in detail, the present invention largely consists of a chamber housing 10, a graphite unit 30, and a vertical heat diffusion plate 20.

The chamber housing 10 provides an accommodating space, which is a sealed space where vacuum pressure is applied, and is formed of copper or an alloy material containing copper or other metal material with excellent thermal conductivity.

This chamber housing 10 is composed of an upper cover 11, a lower cover 13, and a side wall portion 15, and the upper cover 11, lower cover 13, and side wall portion 15 are each molded. After forming the side wall by joining it together through welding or bending the edge of either the upper cover 11 or the lower cover 13 vertically, the lower cover 13 is attached to the end of the side wall. ) or can be formed by joining the upper cover 11 by welding. The chamber housing 10 of this configuration is substantially similar to the configuration of the previously described embodiment.

The graphite unit 30 is a stack of 2 to 10 graphite sheets 31, and each graphite sheet 31 is proposed to have a thickness of 5 ㎛ to 300 ㎛. Since this graphite unit 30 is substantially the same as the configuration of the previously described embodiment, detailed description will be omitted.

The vertical heat diffusion plate 20 is a type of diaphragm for dividing the internal space of the chamber housing 10 into upper and lower sections, and in the present invention, it is formed of copper, an alloy containing copper, or other metal material with good thermal conductivity. This vertical heat diffusion plate 20 is configured such that its edge portion is connected by welding to the inner surface of the chamber housing 10, and the upper cover 11 or lower cover 13 and the side wall constituting the chamber housing 10. It serves to receive heat transferred from the part 15 and transfer it to each graphite unit 30 disposed on the upper and lower surfaces of the unit 15 to cause a reverse diffusion effect.

The vacuum chamber having a multi-layer graphite laminate with a vertical heat diffusion plate 20 according to the present embodiment configured as described above is configured to conduct heat when the metal chamber housing 10 is in close contact with the heating surface of the electronic device and conducts heat. Heat is dissipated through a reverse diffusion action by two or more graphite units 30 made up of a plurality of graphite sheets 31 that are closely attached to each other by vacuum pressure inside the chamber housing 10.

Hereinafter, a vacuum chamber having a multilayer graphite laminate according to another embodiment of the present invention will be described with reference to FIGS. 12 to 15.

The present invention selectively suppresses the rapid diffusion of heat transferred to the graphite unit 30, which is composed of a plurality of graphite sheets 31, in the vertical direction, so that it can be used in electronic devices with a relatively large area, such as a large-area display. It is proposed as a technical feature that an insulation film 50 or a porous insulation sheet 55 that can ensure uniform heat dissipation characteristics is added.

The first embodiment proposed by the present invention for this purpose proposes molding the upper cover 11 and lower cover 13, which constitute the chamber housing 10, from different metal materials, as shown in FIG. 12. In this case, it is proposed that the upper cover 11 is made of a metal material with a low heat transfer rate relative to the lower cover 13.

For example, if the lower cover 13 is molded from copper, the upper cover 11 may be molded from a metal material such as magnesium, nickel, iron, lead, or antimony, which has a lower heat transfer rate than copper.

In this way, in the case where the upper cover 11 is made of a metal material whose heat transfer rate is lower than that of the lower cover 13, the heat transferred from the heat source of the electronic device in contact with the lower surface of the lower cover 13 heats several graphite sheets. It is transferred to the stacked graphite unit 30, and the heat transferred to this graphite unit 30 cannot spread quickly in the vertical direction due to the low heat conduction characteristics of the upper cover 11 with respect to the lower cover 13. The diffusion is induced uniformly in the horizontal direction.

Therefore, when applied to electronic devices that require large-area heat dissipation characteristics, such as smartphones and tablet PCs, uniform heat dissipation characteristics can be guaranteed. As a result, performance degradation or damage to the device due to localized heat dissipation can be prevented in advance. It can be prevented.

In the second embodiment proposed by the present invention, as shown in FIGS. 13 and 14, a synthetic resin material is applied to the upper or lower surface of the upper cover 11 constituting the chamber housing 10 to a certain thickness. It is proposed to provide an insulating film 50 made of or by attaching a synthetic resin sheet. Since this insulation film 50 is made of a synthetic resin material, it has a lower thermal conductivity than metal, and as a result, it prevents the heat transferred to the graphite unit from being rapidly transferred in the vertical direction, thereby increasing the horizontal direction of the graphite unit 30. It induces heat diffusion to ensure uniform heat dissipation characteristics.

The third embodiment proposed by the present invention is as shown in Figure 15. A porous insulation sheet 55 made of synthetic resin or metal is provided between the lower surface of the upper cover 11 constituting the chamber housing 10 and the upper surface of the graphite unit 30.

The porous insulation sheet 55 in this embodiment, like the insulation film 50 described above, suppresses heat transfer in the vertical direction so that the heat transferred to the graphite unit 30 can spread in the area direction, that is, the horizontal direction. This ensures uniform heat dissipation characteristics.

Meanwhile, the present invention is not limited to the described embodiments, and can be used by changing the application area, and various modifications and variations can be made without departing from the spirit and scope of the present invention. It is self-evident to those with knowledge. Accordingly, such variations or modifications should fall within the scope of the claims of the present invention.

Claims

A chamber housing made of metal by joining an upper cover and a lower cover to form an accommodating space inside which vacuum pressure acts;

A graphite unit made by stacking a plurality of graphite sheets with different thicknesses inside the chamber housing and maintaining the top and bottom closely attached to each other by vacuum pressure acting within the chamber housing. A vacuum chamber having a multi-layer graphite laminate.
The multi-layer graphite laminate according to claim 1, wherein the graphite unit is composed of 2 to 20 graphite sheets having different thicknesses, wherein each graphite sheet is provided with a thickness of 5㎛ to 300㎛. Having a vacuum chamber.
The method of claim 1, wherein the chamber housing includes a lower cover whose edge protrudes upward as the graphite unit is raised, an upper cover provided in a shape corresponding to the upper side of the lower cover and forming a receiving space together with the lower cover, and the chamber housing. A side wall seals the internal receiving space by joining the edges of the upper and lower covers, and divides the receiving space into upper and lower parts to form a space for accommodating a plurality of graphite units, the edge of which is connected to the inner wall of the side wall. A vacuum chamber having a multi-layer graphite laminate, characterized in that it consists of one or a plurality of vertical heat diffusion plates made of metal plates that transmit heat.
According to claim 1, wherein the graphite unit is an upwardly increasing thickness type graphite unit in which graphite sheets of increased thickness are sequentially stacked on the upper side of the lowermost graphite sheet as a reference. Or, a downward thickness increasing type graphite unit that sequentially stacks graphite sheets of reduced thickness on the upper side based on the graphite sheet located at the bottom;, or a random graphite unit that randomly stacks graphite sheets of different thicknesses. A vacuum chamber having a multi-layer graphite laminate, characterized in that:
A lower cover made of a metal material provided in the form of a plate, an upper cover disposed opposite to the upper side thereof and made of a metal material with low thermal conductivity with respect to the lower cover to block heat transmitted in the vertical direction, and an edge of the lower cover and the upper cover A chamber housing consisting of a side wall that is joined to form an accommodating space where vacuum pressure is applied;

Thermal diffusion is induced in the horizontal direction by the upper cover, which is provided in the receiving space and has low thermal conductivity, and 2 to 20 graphite sheets with a thickness of 5㎛ ~ 300㎛ are stacked and each graphite sheet is brought into close contact with each other by vacuum pressure. A vacuum chamber having a multi-layer graphite laminate, characterized in that it consists of a graphite unit provided in a state.
An upper cover equipped with a heat transfer element to block heat transfer in the vertical direction, a lower cover disposed oppositely on the lower side thereof, and one or both of the edges of the upper cover and the lower cover are protruded and joined to the inside. A chamber housing consisting of a side wall forming a vacuum accommodation space;

A vacuum chamber having a multi-layer graphite laminate, characterized in that it is composed of a graphite unit, which is made by stacking a plurality of graphite sheets in the receiving space and each graphite sheet is provided in close contact with each other by vacuum pressure.
The method according to claim 5 or 6, wherein the graphite unit is an upwardly increasing thickness type graphite unit in which graphite sheets of increased thickness are sequentially stacked on the upper side of the lowermost graphite sheet as a reference; . Or, a downward thickness increasing type graphite unit that sequentially stacks graphite sheets of reduced thickness on the upper side based on the graphite sheet located at the bottom;, or a random graphite unit that randomly stacks graphite sheets of different thicknesses. A vacuum chamber having a multi-layer graphite laminate, characterized in that:
The method of claim 6, wherein the blocking element is an insulating film formed by coating a synthetic resin material or attaching a sheet of synthetic resin material to the upper or lower surface of the upper cover to reduce heat transfer in the vertical direction; or A vacuum chamber having a multi-layer graphite laminate, characterized in that it is one of porous insulation sheets made of metal or synthetic resin and provided to reduce heat transfer in the vertical direction between the lower surface of the upper cover and the upper surface of the graphite unit.