KR20110139327A - Water repellent heat sink and method for manufacturing thereof - Google Patents

Abstract

PURPOSE: A water repellent heat sink and a manufacturing method thereof are provided to prevent the surface of the heat sink from being soaked, thereby maximizing a heat sink function. CONSTITUTION: A water repellent heat sink(100) includes a heat sink body(110), a DLC(Diamond Like Carbon Layer)(120), and a water repellent feature providing unit(130). The heat sink body forms the appearance of the heat sink with a water repellent feature. The heat sink body comprises a base(111) and a plurality of protrusions(112) which is protruded from the base. The heat sink body is made of non-ferrous metal with a lower thermal transmission resistance value. The DLC layer is formed on the surface of the heat sink body. A micro structure is formed on the heat sink body. The DLC layer is formed on the micro structure.

Description

Heat sink having super water repellency and its manufacturing method {WATER REPELLENT HEAT SINK AND METHOD FOR MANUFACTURING THEREOF}

The present invention relates to a heat sink having a super water repellency and a method for manufacturing the same, and more particularly, a heat sink having a super water repellency capable of preventing corrosion and maximizing a natural heat dissipation function by preventing the surface from getting wet with water. It relates to a manufacturing method.

Heat generated from an electronic device or an electronic device (hereinafter, referred to as an electronic device) is directly related to device or device life, operation error, and reliability. Therefore, thermal management in electronic devices is one of the important factors that determine device performance.

For example, a central processing unit (CPU) of a computer may have an operating error and shorten its life when the temperature rises due to heat generated during operation. Therefore, the heat dissipation problem must be solved so that the central processing unit can be maintained within an appropriate temperature range.

In addition, in the case of LED, which is widely used as a light source in recent years, in order to improve durability by preventing damage to the CPU, memory, and circuit circuits in the PCB (Printed Circuit Board) where the LED is mounted If so, the heat dissipation problem should be properly addressed.

The heat sink is mainly used as a solution to the heat dissipation problem of the electronic devices. The heat sink is a cooling radiator coupled to the electronic device to absorb and radiate heat generated from the electronic devices to the outside, and the heat sink prevents a rapid temperature rise of the electronic device.

Meanwhile, in the case of a heat sink in which an electronic device is an internal component mounted inside a computer and the like and coupled to the internal component, contact with water may not be made, but in the case of an external heat sink, rain water may be in contact with each other. . If water is in contact with the heat sink and flows down, there is no problem. However, if water is kept wet in the heat sink, it may cause corrosion and heat dissipation.

Therefore, the heat sink preferably has a water repellent function, that is, water repellency, which means it is difficult to get wet with water, and thus helps to solve the heat dissipation problem of the electronic device to which the heat sink is coupled.

This water repellency has been studied from a field of engineering intended to be inspired by natural nanostructures, that is, surface modification technology to control the wetting of the surface. The focus is on chemically surface modification to prevent the liquid from getting wet on the surface of the solid by increasing the contact angle and decreasing the flow angle when the liquid contacts the surface of the solid.

For example, the surface of an automobile glass or a building window glass has a relatively low contact angle with water of about 20 ° to 40 °, so that water flows in the form of an uneven water film during rain. This heterogeneous water film causes light scattering in the case of automobile glass, thereby obstructing the driver's vision, especially in rainy weather or at night driving, and easily contaminates the surface with dust, yellow sand, etc. in the case of building glass windows. If the surface energy of the glass surface can be significantly lowered, it is possible to round the adhesion form of the water droplets, and the water droplets can be rolled down into a spherical shape, which makes it difficult to wet the water in most glass.

Therefore, although continuous research on water repellency is required, considering that water-repellent products, especially heat sinks having super water-repellency, have not been developed or released as a product, it is expected that this study will be necessary.

It is an object of the present invention to provide a heat sink having a super water-repellent property capable of maximizing its heat dissipation function and corrosion prevention by preventing the surface from getting wet with water and a method of manufacturing the same.

The object is a heat sink body; A super water repellency providing unit provided in at least a portion of a surface of the heat sink body; And a DLC layer (Diamond Like Carbon Layer) of water-repellent material formed on the super water-repellent providing portion; It is achieved by a heat sink having a super water-repellent, characterized in that it comprises a.

Here, the super water repellent providing unit is provided by a surface roughness formed under the surface of the DLC layer of the water-repellent material so that the surface of the DLC layer of the water-repellent material has a relatively large contact angle or a relatively small flow angle of a predetermined level. Can be.

The surface roughness may be processed over the entire area or part of the surface prior to the deposition of the DLC layer by micro / nanoparticle spray, compressed air blasting, sand blasting, polishing, forging or flattening.

The surface roughness portion may be integrally molded using a mold when the heat sink is formed by extrusion molding.

The super water-repellent providing unit may be a micro structure having an uneven shape coupled to at least a portion of a portion below the surface of the DLC layer.

The microstructure may include a plurality of unit members that are laterally interconnected.

Each of the plurality of unit members includes a base plate; And a protrusion protruding in a direction intersecting the plate surface of the base plate in a central region of the base plate.

The surface to which the microstructures are coupled may form an inclined surface.

On the other hand, the object is to prepare a heat sink body; Forming a super water repellent providing portion in at least a portion of a surface of the heat sink body; And forming a water repellent DLC layer (Diamond Like Carbon Layer) on the super water repellent providing unit. It can be achieved by a method of manufacturing a heat sink having a super water-repellent comprising a.

According to the present invention, the surface is not wetted with water, thereby maximizing the natural heat dissipation function.

1 is a perspective view of a heat sink having super water repellency according to a first embodiment of the present invention;
2 is a side view of FIG. 1;
3 and 4 are comparative examples of the contact angle and the flow angle to explain the super water repellency of the water repellent surface and the surface having a micro structure,
5 is an electron micrograph of a surface of a heat sink on which surface roughnesses are formed;
6 is a side view of a heat sink having water repellency according to a second embodiment of the present invention;
FIG. 7 is a perspective view of the microstructure shown in FIG. 6;
8 is an enlarged perspective view of the unit member illustrated in FIG. 7;
9 is a side view of a heat sink having super water repellency according to a third embodiment of the present invention,
10 is a side view of a heat sink having super water repellency according to a fourth embodiment of the present invention.

Objects, other objects, features and advantages of the present invention will be readily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In this specification, when an element is referred to as being on another element, it may be directly formed on another element, or a third element may be interposed therebetween. Also in the figures, the thickness of the components is exaggerated for an effective description of the technical content.

Embodiments described herein will be described with reference to cross-sectional and / or plan views, which are ideal exemplary views of the present invention. In the drawings, the thicknesses of films and regions are exaggerated for effective explanation of technical content. Therefore, the shape of the exemplary diagram may be modified by manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention are not limited to the specific forms shown, but also include changes in the shapes that are produced according to the manufacturing process. For example, the etched regions shown at right angles may be rounded or have a predetermined curvature. Thus, the regions illustrated in the figures have attributes, and the shapes of the regions illustrated in the figures are intended to illustrate specific forms of regions of the elements and are not intended to limit the scope of the invention. Although the terms first, second, etc. have been used in various embodiments of the present disclosure to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. The embodiments described and illustrated herein also include complementary embodiments thereof.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, the words 'comprises' and / or 'comprising' do not exclude the presence or addition of one or more other components.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In describing the specific embodiments below, various specific details are set forth in order to explain the invention more specifically and to help understand. However, one of ordinary skill in the art can understand that the present invention can be used without these various specific details. In some cases, it is mentioned in advance that parts of the invention which are commonly known in the description of the invention and which are not highly related to the invention are not described in order to prevent confusion in explaining the invention without cause.

1 is a perspective view of a heat sink having super water repellency according to a first embodiment of the present invention, FIG. 2 is a side view of FIG. 1, and FIGS. 3 and 4 illustrate super water repellency of a water repellent surface and a surface having a micro structure. FIG. 5 is an electron micrograph of a surface of a heat sink on which surface roughnesses are formed.

As shown in these figures, the heat sink 100 having the water repellency of the present embodiment includes a heat sink body 110, a DLC layer (Diamond Like Carbon Layer, 120), and a super water repellent providing unit 130. .

The heat sink main body 110 forms the appearance of the heat sink 100 having the super water repellency of the present embodiment. The heat sink body 110 includes a base 111 and a plurality of protrusions 112 formed on the surface of the base 111 and protruding side by side at equal intervals from each other on the surface of the base 111. Of course, the appearance of Figures 1 and 2 is only one embodiment, the scope of the present invention is not necessarily limited to the shape shown.

In the present embodiment, the protrusion 112 is a straight line, but unlike the illustrated figure, the protrusion 112 may have an English T-shape.

In addition, in the present embodiment, the base 111 is made of a flat plate body, but unlike the illustrated, may have an arc (ARC) shape or hemispherical shape. The former case will be easy to apply to the electronic device 1 such as the CPU of a computer which is flat among the electronic devices, and the latter case will be easy to apply to the LED lamp.

The heat sink body 110 is made of a non-ferrous metal having a low heat resistance, that is, good heat transfer, and low heat transfer resistance. Preferred materials may be copper or aluminum in view of high cost.

In the present embodiment, the heat sink body 110 is manufactured in a structure in which all outer surfaces are blocked, but a plurality of through holes (not shown) may be formed in the heat sink body 110 as necessary. Multiple apertures can provide more advantageous effects in providing a heat dissipation effect.

A DLC layer (Diamond Like Carbon Layer) 120 is formed on the surface of the heat sink body 110 as shown in FIG. 2. According to one embodiment of the invention, the DLC layer is formed so that the surface of the heat sink body 100 has a roughness, it may be formed thereon. According to another embodiment of the present invention, a micro structure for improving a flow angle on the surface of the heat sink body 100 may be formed, and a DLC layer may be formed on the micro structure.

That is, when the heat sink body 110 is manufactured, surface roughness may be given through processing for super water repellency, and when the heat sink is formed by extrusion molding, a surface having an integral roughness may be molded using a mold. . In addition, in order to improve the contact angle as well as the flow angle, a directional uneven microstructure may be processed on the surface. The water repellent DLC layer 120 may be post-treated on the surface by coating.

The DLC layer 120 of the water-repellent material should have a good thermal conductivity so that heat generated from the electronic device 1 can be quickly transferred to the heat sink body 110 to dissipate heat. As a result, the DLC layer 120 having a water repellent property serves to transfer heat from the electronic device 1 to the entire area of the heat sink body 110, and the thickness of the DLC layer 120 is preferably 0.1 to 5 μm. Do. If the thickness of the DLC layer 120 is 5 µm or more, defects such as cracks may occur and may affect thermal conductivity.

The DLC layer 120 may be formed by a physical vapor deposition (PVD) process or a plasma enhanced chemical vapor deposition (PECVD) process.

On the other hand, the super water-repellent providing unit 130 is formed under the surface of the DLC layer 120, serves to provide super water-repellency to the DLC layer 120 so that the surface of the DLC layer 120 is not wet with water. In detail, the shape of the super water repellency providing unit 130 may have a rough or micro structure, and since the DLC layer 120 is formed on the shape, the shape of the DLC layer 120 may be rough or micro structure. It follows structural features.

As described above, water repellency refers to a property that is difficult to get wet with water. When water comes into contact with the surface of the solid, the contact angle is increased through the surface treatment of the solid and the flow angle is reduced to prevent the water from getting wet on the surface of the solid. You can do that. The larger contact angle and the smaller flow angle mean that the surface energy is significantly lowered to round the droplets so that the rounded droplets can easily flow off the surface of the solid. In particular, super water repellency is a property of contact surface with water is more than 150 ° and the flow angle is less than 5 ° is a property of very good water repellency.

Meanwhile, FIG. 5 is an electron micrograph of the surface of the heat sink 100 having the surface roughness portion. Referring to FIGS. 3 to 5, the contact angle and the flow angle will be described. As shown in FIGS. 3 and 4, the larger the contact angle CA is, The smaller the flow angle SA, the lower the surface energy at the solid surface may be. Therefore, the shape of the water droplets can be kept more rounded as shown in FIG. 4, so that the water droplets can easily fall off without sticking to the solid surface, that is, the surface of the DLC layer 120 in the present embodiment, thereby improving water repellency to show super water repellency. do.

In the present embodiment, the super water repellent providing unit 130 is formed below the surface of the water repellent DLC layer 120 such that the surface of the DLC layer 120 has a relatively large contact angle or a relatively small flow angle at a predetermined level. It is provided by the surface roughness.

At this time, the surface roughness portion as the super water-repellent providing portion 130, before the surface of the DLC layer 120 before deposition by micro / nanoparticle spray, compressed air blasting, sand blasting, polishing, forging or flattening It can be machined over an area or part.

Micro / nanoparticle spray is a method of spraying micro / nanoparticles that can be physically bonded to a heat sink material by a general spray method, and compressed air blasting is a method of spraying compressed air strongly onto the surface of the heat sink body 110 to obtain a desired surface. Sandblasting is a method of forming a roughness portion, and sandblasting is a method of forming a desired surface roughness portion by spraying sand instead of compressed air. Polishing is a method of forming a desired surface roughness by using sandpaper, etc., the forging method is a method of forming a desired surface roughness by hitting a separate tool to the surface of the DLC layer 120 of the heat sink body 110, Machining is a method of forming a desired surface roughness using a milling machine or other machine tool.

Of course, since the scope of the present invention can not be limited to this, instead of the above processing, the surface roughness of the heat sink 100 as the super water-repellent providing unit 130 as shown in the enlarged portion of FIG. It can also be molded integrally.

For reference, the surface roughness portion as the super water-repellent providing portion 130 drawn in the enlarged portion of FIG. 2 is shown to be exaggerated somewhat, and the actual surface roughness portion will be fine enough to be viewed with a microscope.

Whichever method is applied, as shown in the enlarged part of FIG. 2, when the surface roughness portion of the heat sink body 110 as the super water-repellent providing portion 130 is formed to a desired level and the surface coating of the DLC layer 120 of the water-repellent material is performed, a relatively large contact angle Alternatively, the surface energy of the relatively small flow angle is lowered so that the surface of the DLC layer 120 is wet with water. Therefore, it is possible to prevent the phenomenon that the heat dissipation function of the heat sink 100 is deteriorated.

According to the heat sink 100 having a super water-repellent property of the present invention having such a structure, it is possible to maximize the natural heat dissipation function by preventing the surface from getting wet with water.

FIG. 6 is a side view of a heat sink having super water repellency according to a second embodiment of the present invention, FIG. 7 is a perspective view of the microstructure shown in FIG. 6, and FIG. 8 is an enlarged perspective view of the unit member shown in FIG. 7. .

As shown in these figures, the heat sink 200 having the water repellency of the present embodiment is also formed on the surface of the base 211 and the base 211 and protrudes side by side at equal intervals from each other on the surface of the base 211. The embodiment described above in that it includes a heat sink body 210 having a plurality of protrusions 212 and a DLC layer (Diamond Like Carbon Layer, 220) formed on the surface of the heat sink body 210; The same, but in the present embodiment, the super water-repellent providing unit 230 is different from the embodiment described above.

In the present embodiment, the super water-repellent providing unit 230 is provided with a micro structure 230 having a concave-convex shape that is coupled to at least a portion below the surface of the DLC layer 220.

As illustrated in FIGS. 7 and 8, the microstructure 230 may be formed of a plurality of unit members 230a which are laterally interconnected. In this case, each of the plurality of unit members 230a includes a base plate 231 and a protrusion 232 protruding in a direction crossing the plate surface of the base plate 231 in the central region of the base plate 231.

Although shown in the block structure of a certain size (block) in the drawings for convenience of illustration is somewhat exaggerated, the size of one unit member (230a) is very small. That is, as shown in Figure 8, each of the portions (A, B, C, D) has a length of about 40 ㎛, 8 ㎛, 18 ㎛, 10 ㎛.

The structure of one unit member 230a is the same as that of FIG. 8, but when they are connected laterally, for example, nine, the unit member 230a may have the shape of FIG. 7. Can have

Therefore, when the microstructure 230 is applied to the super water-repellent providing unit 230, the effect of water droplets flowing well in one direction can be maximized, as in the principle of rice leaves. Water may be prevented from getting wet on the surface of the 200. Since it is not easy to manufacture by connecting the micro-structure 230, it would be desirable to extrude the heat sink using a method of depositing and etching semiconductors directly on the heat sink or using a mask manufactured by the method.

9 is a side view of a heat sink having super water repellency according to a third embodiment of the present invention, and FIG. 10 is a side view of a heat sink having super water repellency according to a fourth embodiment of the present invention.

In the case of this embodiment, it has a structure substantially similar to that of the second embodiment described above. However, in the heat sink 300 of FIG. 9, the surface S1 to which the microstructures 330 are coupled to each other forms an inclined surface inclined to one side. In the heat sink 400 of FIG. The surface S2 to which the structure 330 is coupled is inclined symmetrically on both sides. Such a case is also sufficiently possible, but in the case of FIGS. 9 and 10, it is expected that the flow angle can be kept small to contribute to the increase of the super water repellency.

Even if these embodiments are applied, it is sufficient to maximize the natural heat dissipation function by preventing the surface from getting wet.

Now, a method of manufacturing a heat sink having super water repellency according to an embodiment of the present invention will be described. According to the present embodiment, preparing a heat sink body, forming a super water repellent providing portion on at least a part of the surface of the heat sink body, and forming a water repellent DLC layer (Diamond Like Carbon Layer) on the super water repellent providing portion Steps.

According to one embodiment of the present invention, the super water-repellent providing unit, the surface roughness formed under the surface of the DLC layer of the water-repellent material so that the surface of the DLC layer has a relatively large contact angle or relatively small flow angle of a predetermined level It can be formed by the base.

Meanwhile, the surface roughness portion may be processed over the entire area or part of the surface before the deposition of the DLC layer of the water-repellent material by micro / nanoparticle spray, compressed air blasting, sand blasting, polishing, forging or flattening. have. In addition, the surface roughness portion may be integrally molded using a mold when the heat sink is formed by extrusion molding.

The water repellent super water repellent may be configured in the form of an uneven microstructure that is coupled to at least some sections below the surface of the DLC layer. Here, the microstructure may be formed to include a plurality of unit members that are laterally interconnected. In addition, each of the plurality of unit members may be provided to include a base plate and a protrusion protruding in a direction intersecting the plate surface of the base plate in the central region of the base plate, the surface to which the microstructure is coupled It can be configured to form a sloped surface.

While various embodiments of the present invention have been described above, the scope of the present invention is not limited to the above description.

In addition to the above description, the method of forming the surface roughness may include sand casting, permanent mold casting, die casting, extrusion, rolling, shell milling. , Face milling, turning, drilling, reaming, boring, grinding, honing, lapping, etc. However, these are only methodological differences, and the surface roughness may be selectively changed as needed.

In addition, in the above-described embodiment, the meaning that the DLC layer of the water repellent is formed on the super water repellent providing part is used as a concept including both the case where other components are inserted and not inserted between the DLC layer of the water repellent and the super water repellent providing part. do. For example, even if other components are inserted, if the DLC layer can reflect the shape provided by the super water-repellent providing part, it may be included in the scope of the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

100: heat sink 110: heat sink body
120: DLC layer 130: super water-repellent providing unit

Claims (9)

Heat sink body;
A super water repellency providing unit provided in at least a portion of a surface of the heat sink body; And
A water repellent DLC layer (Diamond Like Carbon Layer) formed on the super water repellent providing portion; Heat sink having a super water-repellent comprising a. The method of claim 1,
The super water repellent providing portion is provided by a surface roughness formed under the surface of the DLC layer of the water repellent so that the surface of the DLC layer of the water repellent has a relatively large contact angle or a relatively small flow angle of a predetermined level. A heat sink having super water repellency characterized by the above-mentioned. The method of claim 2,
The surface roughness may be processed over the entire area or part of the surface before deposition of the DLC layer by micro or nanoparticle spraying, compressed air blasting, sand blasting, polishing, forging or flattening. Heat sink with water repellency. The method of claim 2,
The surface roughness portion, the heat sink having a super water-repellent, characterized in that integrally molded using a mold when the heat sink is formed by extrusion molding. The method of claim 1,
The super water-repellent providing unit, the heat sink having a super water-repellent, characterized in that the microstructure of the concave-convex shape coupled to at least a portion below the surface of the DLC layer of the water-repellent material. The method of claim 5,
The microstructure is a heat sink having a super water-repellent, characterized in that it comprises a plurality of unit members are laterally interconnected. The method of claim 6,
Each of the plurality of unit members,
Base plate; And
And a protrusion protruding in a direction intersecting the plate surface of the base plate in a central region of the base plate. The method of claim 5,
The surface to which the microstructure is coupled is a heat sink having a super water-repellent, characterized in that to form a sloped surface. Preparing a heat sink body;
Forming a super water repellent providing portion in at least a portion of a surface of the heat sink body; And
Forming a DLC layer (Diamond Like Carbon Layer) of water repellent on the super water repellent providing unit; Method for producing a heat sink having a super water-repellent comprising a.

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