HEAT-DISSIPATING SUBSTRATE

Abstract

Disclosed herein is a heat-dissipating substrate in order to improve heat-dissipating characteristics. The heat-dissipating substrate, comprising: a copper layer having a predetermined thickness; anodized insulating layers formed on upper and lower surfaces of the copper layer; and aluminum (Al) layers formed between the copper layer and the anodized insulating layer. Therefore, a heat-dissipating function of the base made of the aluminum (Al) layer and the copper (Cu) layer is improved, thereby making it possible to provide a high-output metal substrate appropriate for high-integration/high capacity electronic components.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2010-0108130, filed on Nov. 2, 2010, entitled “Heat-Dissipating Substrate and Fabricating Method of The Same”, which is hereby incorporated by reference in its entirety into this application.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a heat-dissipating substrate.

2. Description of the Related Art

Generally, with the development of a high-degree technology industry such as vehicles, a demand for high-integration/high-capacity electronic components used therefor has also correspondingly increased.

In fabricating the high-integration/high-capacity electronic component, heat-dissipation has been importantly considered. That is, each of the high-integration/high-capacity electronic components on the substrate generates high heat, which causes a function of each of the electronic components to be deteriorated.

Accordingly, a demand for development of a substrate with high dissipating characteristics capable of rapidly and smoothly dissipating heat generated from each of the high-integration/high-capacity electronic components to the outside has increased.

Since an organic printed circuit board (PCB) or a metal substrate according to the prior art has low dissipating characteristics, it has a restriction in being used as a high-output substrate. An anodized aluminum substrate has improved dissipating characteristics as compared to the organic PCB and the metal substrate; however, has a restriction in being used as the high-output substrate due to a limitation in thermal conductivity of aluminum.

For example, the anodized aluminum substrate 10 is formed by forming an anodized insulating layer 12 on a surface of an aluminum disc 11 through an anodizing process, forming a metal layer 13 thereon through a dry sputtering process or a wet electroless/electro plating process and forming a pattern on the metal layer 13 through a dry/wet etching process or a lift-off process, as shown in FIG. 1. It is difficult to use the anodized aluminum substrate as the high-output substrate due to the limitation in thermal conductivity of aluminum (for example, 5052 aluminum alloy; ˜140 W/m·K).

SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide a heat-dissipating substrate capable of improving the heat-dissipating function by using a multi-layer structure made of a copper (Cu) layer and an aluminum (Al) layer.

Further, the present invention has been made in an effort to provide a heat-dissipating substrate capable of improving heat-dissipating characteristics and minimizing weight increase by adjusting the thickness ratio of a copper (Cu) layer and an aluminum (Al) layer.

According to a first preferred embodiment of the present invention, there is provided A heat-dissipating substrate, comprising: a copper layer having a predetermined thickness; and anodized insulating layers formed on upper and lower surfaces of the copper layer.

The heat-dissipating substrate may further include aluminum (Al) layers formed between the copper layer and the anodized insulating layer.

Further, The heat-dissipating substrate may further include a seed layer formed on the part of anodized insulating layer; and a metal layer formed on the seed layer.

The anodized insulating layer is formed on the surface of the aluminum layer through an anodizing process.

The aluminum layers are formed at a thickness of 0.02 mm˜0.2 mm.

The copper layer and the aluminum layers are formed at a thickness ratio of 2:2 to 3:1.

The seed layer is performed by electroless plating or sputtering deposition.

The metal layer is performed by wet plating or dry sputtering deposition.

The seed layer is formed on the entire surface of anodized insulating layer, the metal layer is formed on the seed layer, and a part of the seed layer and the metal layer is removed by wet chemical etching, electrolytic etching or lift-off.

According to a Second preferred embodiment of the present invention, there is provided A heat-dissipating substrate, comprising: a copper layer having a first area and second area of the upper surface or lower surface, and a predetermined thickness; aluminum layers formed on first area of the upper surface or the lower surface; and anodized insulatings layer formed on second area of the upper surface or the lower surface of the copper layer.

Further, The heat-dissipating substrate may further include a seed layer formed on the part of anodized insulating layer; and a metal layer formed on the seed layer.

The anodized insulating layer is formed on the surface of the aluminum layer through an anodizing process.

The aluminum layers are formed at a thickness of 0.02 mm˜0.2 mm.

The copper layer and the aluminum layers are formed at a thickness ratio of 2:2 to 3:1.

The seed layer step is performed by electroless plating or sputtering deposition.

The metal layer is performed by wet plating or dry sputtering deposition.

The seed layer is formed on the entire surface of anodized insulating layer, the metal layer is formed on the seed layer, and a part of the seed layer and the metal layer is removed by wet chemical etching, electrolytic etching or lift-off.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view showing an anodized aluminum substrate according to the prior art;

FIG. 2 is a cross-sectional view showing a first embodiment of an anodized multi-layer metal substrate to which the present invention is applied;

FIGS. 3A to 3E are process views showing a first embodiment of a fabricating method of an anodized multi-layer metal substrate to which the present invention is applied;

FIGS. 4A to 4E are process views showing a second embodiment of a fabricating method of an anodized multi-layer metal substrate to which the present invention is applied;

FIGS. 5A to 5E are process views showing a third embodiment of a fabricating method of an anodized multi-layer metal substrate to which the present invention is applied;

FIG. 6 is a cross-sectional view showing a third embodiment of an anodized multi-layer metal substrate to which the present invention is applied;

FIG. 7 is a graph showing thermal conductivity depending on the change in the thickness of a copper layer in an anodized multi-layer metal substrate to which the present invention is applied; and

FIG. 8 is a graph showing thermal conductivity depending on the change in the thickness of a copper layer in an anodized multi-layer metal substrate to which the present invention is applied.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various features and advantages of the present invention will be more obvious from the following description with reference to the accompanying drawings.

The terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions, but should be interpreted as having meanings and concepts relevant to the technical scope of the present invention based on the rule according to which an inventor can appropriately define the concept of the term to describe most appropriately the best method he or she knows for carrying out the invention.

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. In the specification, in adding reference numerals to components throughout the drawings, it is to be noted that like reference numerals designate like components even though components are shown in different drawings. Further, when it is determined that the detailed description of the known art related to the present invention may obscure the gist of the present invention, the detailed description thereof will be omitted.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A fabricating method of a heat-dissipating substrate according to a preferred embodiment of the present invention includes (A) forming aluminum (Al) layers (120) on upper and lower surfaces of a copper (Cu) layer 110 and (B) forming anodized insulating layers 130 on surfaces of upper and lower aluminum layers, as shown in FIGS. 2 to 8.

Accordingly, an anodized multi-layer metal substrate 100, which is a heat-dissipating substrate according to the preferred embodiment of the present invention, forms the copper layer 110 having thermal conductivity of ±350 W/m·K between the upper and lower aluminum layers 120 having thermal conductivity of ±140 W/m·K to have total thermal conductivity 140 to 350 W/m·K. At this time, thermal conductivity and weight of the anodized multi-layer metal substrate 100 may be adjusted according to the thicknesses of the copper layer 110 and the aluminum layers 120.

At step (A), for example, in the state in which the aluminum layers 120 in a plate form are closely attached on and beneath the copper layer 110, the aluminum layers may be bonded onto the copper layer by rolling.

The aluminum layers 120 are formed on the upper and lower surfaces of the copper layer 110 in order to form the anodized insulating layers 130 by an anodizing process. In order to form the anodized insulating layer 130, the aluminum layer should be formed at a thickness of at least 0.02 mm or more.

The thickness ratio of the copper layer 110 and the aluminum layers 120 may be adjusted to have thermal conductivity in the range of 140 to 350 W/m·K. For example, as shown in FIG. 7, in the case in which the total thickness of the copper layer 110 and the aluminum layers 120 except the anodized insulating layer 130 is 4 mm, when the thickness of the copper layer 110 is 2 mm, thermal conductivity of the anodized multi-layer metal substrate 100 is 200 W/m·K, and when the thickness thereof is 3 mm, thermal conductivity thereof is 255 W/m·K.

The thickness ratio of the copper layer 110 and the aluminum layers 120 may be adjusted to have the weight of the anodized multi-layer metal substrate 100 in the range of 11 to 35 kg/m². For example, as shown in FIG. 8, in the case in which the total thickness of the copper layer 110 and the aluminum layers 120 except the anodized insulating layer 130 is 4 mm, when the thickness of the copper layer 110 is 2 mm, the weight of the anodized multi-layer metal substrate 100 is 23.5 kg/m², and when the thickness thereof is 3 mm, the weight thereof is 29.5 kg/m².

Accordingly, as shown in FIGS. 7 and 8, the copper layer 110 and the aluminum layers 120 are formed at a thickness ratio of 2:2 to 3:1 to maintain optimal thermal conductivity and weight.

At step (B), for example, the anodized insulating layers 130 are formed on the surfaces of the upper and lower aluminum layers 120 through the anodizing process. At this time, as an example, it is possible to allow the entire or partial thickness of the aluminum layers 120 to become the anodized insulating layers 130 and allow the entire or partial surface of the aluminum layers 120 to become the anodized insulating layers 130, through the anodizing process.

That is, the anodized insulating layers 130 are formed by oxidizing the aluminum layers 120 through the anodizing process. In a first embodiment, a predetermined thickness with respect to the entire surface of the aluminum layers 120 becomes the anodized insulating layers 130, as shown in FIGS. 2 and 3A to 3E. In a second embodiment, the entire thickness with respect to the entire surface of the aluminum layers 120 becomes the anodized insulating layers 130, as shown in FIGS. 4A to 4E. In a third embodiment, the entire thickness with respect to the partial surface of the aluminum layers 120 becomes the anodized insulating layers 130, as shown in FIGS. 5A to 5E and 6.

Meanwhile, although not included in the embodiments, the partial thickness with respect to the partial surface of the aluminum layers 120 may become the anodized insulating layers 130. It may be predicted by claim 3 and claim 4 of the present invention that the aluminum layers 120 may be formed both on and beneath the copper layer 110.

While heat-dissipation may be performed in a horizontal direction along the copper layer 110 in the first and second embodiments, heat-dissipation may be performed in a vertical direction along the aluminum layers while being performed in the horizontal direction in the third embodiment.

Meanwhile, the fabricating method of the heat-dissipating substrate according to the preferred embodiment of the present invention further includes (C) forming a seed layer 140 on the anodized insulating layer 130, (D) forming a metal layer 150 on the seed layer 140 and (E) partially removing the seed layer 140 and the metal layer 150 to form a pattern.

At step (C), the seed layer 140 may be formed by electroless plating or sputtering deposition, for example. That is, the electroless plating or the sputtering deposition is used in order to form the seed layer 140 on the anodized insulating layer 130 that does not pass electricity.

At step (D), the metal layer 150 is formed by wet plating or dry sputtering deposition.

At step (E), the seed layer 140 and the metal layer 150 are partially removed by wet chemical etching, electrolytic etching or lift-off to form the pattern.

Each of the embodiments of a fabricating method of a heat-dissipating substrate and a heat-dissipating substrate fabricated using the fabricating method according to a preferred embodiment of the present invention will be described in detail below.

In the first embodiment, the aluminum layers 120 are bonded onto the upper and lower surfaces of the copper layer 110 at a thickness of at least 0.02 mm or more by rolling, as shown in FIG. 3A. Then, in the state of connecting the aluminum layers 120 to electrodes, an electrolyte is injected therein to form the anodized insulating layers 130 on the surfaces of the aluminum layers 120.

In this case, the anodized insulating layers 130 are uniformly formed over the entire surfaces of the aluminum layers 120 as shown in FIG. 3B. The amount of time of the anodizing process is adjusted, such that the aluminum layers 120 having a predetermined thickness remain on the upper and lower surfaces of the copper layer 110.

Thereafter, the seed layer 140 is formed on the anodized insulating layer 130 as shown in FIG. 3C, the metal layer 150 is formed on the seed layer as shown in FIG. 3D, and the seed layer 140 and the metal layer 150 are partially removed to form the pattern as shown in FIG. 3E.

According to the fabricating method of the present invention as described above, the anodized multi-layer metal substrate 100, which is the heat-dissipating substrate, including a configuration made of the copper (Cu) layer 110 having a predetermined thickness, the aluminum (Al) layers 120 formed on and beneath the copper layer 110 and the anodized insulating layers 130 formed on the surfaces of the upper and lower the aluminum layers 120, as shown in FIG. 2, is provided. At this time, the pattern made of the seed layer 140 formed on the anodized insulating layer 130 and the metal layer 150 formed on the seed layer 140 is formed.

In the second embodiment, the aluminum layers 120 are bonded onto the upper and lower surfaces of the copper layer 110 at a thickness of at least 0.02 mm or more by rolling, as shown in FIG. 4A. Then, in the state of connecting the aluminum layers 120 to electrodes, an electrolyte is injected therein to form the anodized insulating layers 130 on the surfaces of the aluminum layer 120.

In this case, the anodized insulating layers 130 are uniformly formed over the entire surface of the aluminum layers 120 as shown in FIG. 4B. The amount of time of the anodizing process is adjusted, such that the entirety of the aluminum layers 120 formed on the surfaces of the copper layer 110 is oxidized.

Thereafter, the seed layer 140 is formed on the anodized insulating layer 130 as shown in FIG. 4C, the metal layer 150 is formed on the seed layer as shown in FIG. 4D, and the seed layer 140 and the metal layer 150 are partially removed to form a pattern as shown in FIG. 4E.

According to the fabricating method of the present invention as described above, the anodized multi-layer metal substrate 100 including a configuration made of the copper (Cu) layer 110 having a predetermined thickness and the anodized insulating layers 130 formed on the upper and lower surfaces of the copper layer 110, as shown in FIG. 4E, is provided. At this time, the pattern made of the seed layer 140 formed on the anodized insulating layer 130 and the metal layer 150 formed on the seed layer 140 is formed.

In the third embodiment, the aluminum layers 120 are bonded onto the upper and lower surfaces of the copper layer 110 at a thickness of at least 0.02 mm or more by rolling, as shown in FIG. 5A. Then, in the state of connecting the aluminum layers 120 to electrodes, an electrolyte is injected therein to form the anodized insulating layers 130 on the surfaces of the aluminum layers 120.

At this time, the anodizing is partially performed on the entire surface of the aluminum layer 120, such that the copper layer having a first area and second area of the upper surface or lower surface, and aluminum layers formed on first area of the upper surface or the lower surface, and anodized insulatings layer formed on second area of the upper surface or the lower surface of the copper layer. In order to selectively perform anodizing, for example, a tape may be adhered or a chemical may be coated so as to prevent oxidation on the surface of the aluminum layer 120. The portion in the aluminum layer 120 subjected to anodizing to become the anodized insulating layer 130 corresponds to an area in which the pattern is subsequently formed. The anodized insulating layer 130 should be formed to be wider than the area in which the pattern is formed, in order to perform an electrical insulation.

Thereafter, the seed layer 140 is formed on the aluminum layer 120 and the anodized insulating layer 130 as shown in FIG. 5C, the metal layer 150 is formed on the seed layer 140 as shown in FIG. 5D, and the seed layer 140 and the metal layer 150 are partially removed to form a pattern as shown in FIG. 5E.

According to the fabricating method of the preferred embodiments of the present invention as described above, the anodized multi-layer metal substrate 100 including a configuration made of the copper (Cu) layer 110 having a predetermined thickness, an aluminum layer 120 formed on the upper or the lower surface of the copper layer 110 and selectively formed in a predetermined area and the anodized insulating layer 130 formed on the upper surface or the lower surface of the copper layer 110 and formed in an area except the aluminum layers 120, as shown in FIG. 6, is provided. At this time, the pattern made of the seed layer 140 formed on the anodized insulating layer 130 and the metal layer 150 formed on the seed layer 140 is formed.

According to the heat-dissipating substrate and the fabricating method of the same of the preferred embodiments of the present invention, the heat-dissipating function is improved through a multi-layer structure made of the copper (Cu) layer and the aluminum (Al) layer, thereby making it possible to provide the high-output metal substrate appropriate for the high-integration/high capacity electronic components.

According to the heat-dissipating substrate and the fabricating method of the same of the preferred embodiments of the present invention, the thickness ratio of the copper (Cu) layer and the aluminum (al) layer is adjusted to improve the heat-dissipating characteristics as well as minimize the weight increase due to the copper, thereby allowing the heat-dissipating substrate to be used as an electrical high-output substrate that needs to have light weight.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, they are for specifically explaining the present invention. Thus a heat-dissipating substrate and a fabricating method of the same according to the present invention are not limited thereto, but those skilled in the art will appreciate that various modifications and alterations are possible, without departing from the scope and spirit of the invention.

Accordingly, such modifications and alterations should also be understood to fall within the scope of the present invention. A specific protective scope of the present invention can be defined by the accompanying claims.

Claims

1. A heat-dissipating substrate, comprising:

a copper layer having a predetermined thickness; and

anodized insulating layers formed on upper and lower surfaces of the copper layer.

2. The heat-dissipating substrate as set forth in claim 1, further comprising aluminum (Al) layers formed between the copper layer and the anodized insulating layer.

3. The heat-dissipating substrate as set forth in claim 2, further comprising:

a seed layer formed on the part of anodized insulating layer; and

a metal layer formed on the seed layer.

4. The heat-dissipating substrate as set forth in claim 2, wherein the anodized insulating layer is formed on the surface of the aluminum layer through an anodizing process.

5. The heat-dissipating substrate as set forth in any one of claim 2, wherein the aluminum layers are formed at a thickness of 0.02 mm˜0.2 mm.

6. The heat-dissipating substrate as set forth in claim 2, wherein the copper layer and the aluminum layers are formed at a thickness ratio of 2:2 to 3:1.

7. The heat-dissipating substrate as set forth in claim 4, wherein the seed layer is performed by electroless plating or sputtering deposition.

8. The heat-dissipating substrate as set forth in claim 4, wherein the metal layer is performed by wet plating or dry sputtering deposition.

9. The heat-dissipating substrate as set forth in claim 4, wherein the seed layer is formed on the entire surface of anodized insulating layer, the metal layer is formed on the seed layer, and a part of the seed layer and the metal layer is removed by wet chemical etching, electrolytic etching or lift-off.

10. A heat-dissipating substrate, comprising:

a copper layer having a first area and second area of the upper surface or lower surface, and a predetermined thickness;

aluminum layers formed on first area of the upper surface or the lower surface; and

anodized insulatings layer formed on second area of the upper surface or the lower surface of the copper layer.

11. The heat-dissipating substrate as set forth in claim 10, further comprising:

a seed layer formed on the part of anodized insulating layer; and

a metal layer formed on the seed layer.

12. The heat-dissipating substrate as set forth in claim 10, wherein the anodized insulating layer is formed on the surface of the aluminum layer through an anodizing process.

13. The heat-dissipating substrate as set forth in claim 10, wherein the aluminum layers are formed at a thickness of 0.02 mm˜0.2 mm.

14. The heat-dissipating substrate as set forth in claim 10, wherein the copper layer and the aluminum layers are formed at a thickness ratio of 2:2 to 3:1.

15. The heat-dissipating substrate as set forth in claim 11, wherein the seed layer step is performed by electroless plating or sputtering deposition.

16. The heat-dissipating substrate as set forth in a claim 11, wherein the metal layer is performed by wet plating or dry sputtering deposition.

17. The heat-dissipating substrate as set forth in claim 11, wherein the seed layer is formed on the entire surface of anodized insulating layer, the metal layer is formed on the seed layer, and a part of the seed layer and the metal layer is removed by wet chemical etching, electrolytic etching or lift-off.