CN100358130C - Radiator and production thereof - Google Patents

Abstract

The heat dissipation device provided by the present invention comprises a heat dissipation base, an aluminum titanium nitride layer formed on the heat dissipation base, a metal catalyst layer formed on the aluminum titanium nitride layer, and a carbon nanotube formed on the metal catalyst layer . In addition, the present invention also provides a method for preparing the above heat dissipation device, which includes the steps of: providing a heat dissipation base; forming an aluminum titanium nitride layer on the heat dissipation base; forming a metal catalyst layer on the aluminum titanium nitride layer ; Growing carbon nanotubes on the metal catalyst layer. The invention uses the aluminum titanium nitride layer as the diffusion barrier layer, which can not only effectively prevent the copper atoms from diffusing into the metal catalyst layer and react with the catalyst particles to affect the growth of carbon nanotubes, but also ensure the high heat dissipation efficiency of the heat sink . In addition, by using the preparation method provided by the present invention, a heat dissipation device with high heat dissipation efficiency can be prepared.

Description

Cooling device and its preparation method

【Technical field】

The invention relates to a heat dissipation device and a preparation method thereof, in particular to a heat dissipation device with high heat dissipation efficiency and a preparation method thereof.

【Background technique】

In recent years, with the rapid development of the information industry, the data processing capability of the heating elements (such as the central processing unit and the graphics card heating elements) installed in the electronic device is also getting stronger. However, as the computing speed of the heating element increases, the heat generated by it also increases significantly. In order to quickly discharge the heat so that the heating element can operate at a normal operating temperature to ensure the quality of data processing, storage and transmission, a heat sink is usually installed on the surface of the heating element to dissipate heat.

The heat dissipation device generally includes a heat sink for dissipating heat, and a thermal interface material between the heating element and the heat sink.

In recent years, carbon nanotubes have become a research hotspot of thermal interface materials because of their extremely high thermal conductivity. Carbon nanotubes are seamless, hollow tubes formed by curling graphite layers formed by carbon atoms. They have excellent axial thermal conductivity, and their thermal conductivity can reach 20,000W/mK (about 50 times that of copper materials), which can greatly improve The heat conduction performance between the heating element and the heat sink improves the heat dissipation performance of the heat dissipation device.

However, most of the bases of existing heat sinks are made of copper material (copper thermal conductivity can reach 402W/mK). Carbon nanotubes are the key.

In the prior art, in order to obtain carbon nanotubes arranged in an orderly manner on the radiator substrate, catalyst particles such as nickel, iron, and cobalt are usually deposited on a copper plate, and then carbon nanotubes are grown by chemical vapor deposition. However, if catalyst particles such as nickel, iron, and cobalt are deposited directly on the copper plate, copper atoms are very easy to diffuse into the catalyst layer due to their very good diffusivity, thereby reacting with the catalyst particles, resulting in failure to grow smoothly. of carbon nanotubes.

In order to solve the problem that the diffusion of copper atoms affects the growth of carbon nanotubes, it is necessary to pre-evaporate or sputter a layer of barrier layer on the copper plate to prevent the phenomenon of copper diffusion. Titanium (TiN) material. For example, Chinese patent application No. 03114708.9 discloses a process of chemical vapor deposition of titanium nitride and copper metal layer damascene. The method is to successively deposit TiN barrier layer and Cu metal film in a multi-cavity vacuum equipment, and Rapid thermal annealing is carried out in the H ₂ -N ₂ atmosphere, so that the barrier layer and the Cu metal film with uniform grain size and resistance distribution are obtained.

But, the TiN barrier layer that above-mentioned method provides, because the thermal conductivity of TiN is only 30W/mK, relatively copper (copper thermal conductivity can reach 402W/mK) and carbon nanotube (thermal conductivity can reach 20000W/mK) In other words, the heat transfer rate is very slow, thus limiting the heat dissipation efficiency of the heat sink as a whole.

【Content of invention】

In order to solve the problem of low heat dissipation efficiency of heat dissipation devices in the prior art, the object of the present invention is to provide a heat dissipation device with high heat dissipation efficiency.

Another object of the present invention is to provide a method for preparing the above-mentioned heat sink.

To achieve the purpose of the present invention, the present invention provides a heat dissipation device, which includes: a heat dissipation base, an aluminum titanium nitride layer formed on the heat dissipation base, a metal catalyst layer formed on the aluminum titanium nitride layer, Carbon nanotubes formed on the metal catalyst layer.

In order to achieve another object of the present invention, the present invention provides a method for preparing a heat dissipation device, which includes the following steps: providing a heat dissipation base; forming an aluminum titanium nitride layer on the heat dissipation base; A metal catalyst layer is formed on the aluminum-titanium layer; carbon nanotubes are grown on the metal catalyst layer.

Compared with the prior art, the present invention uses an aluminum nitride layer as a diffusion barrier layer, which can not only effectively prevent copper atoms from diffusing to the metal catalyst layer and react with catalyst particles to affect the growth of carbon nanotubes, but also aluminum nitride Titanium has a high thermal conductivity, which can also ensure high heat dissipation efficiency of the heat sink.

【Description of drawings】

FIG. 1 is a schematic structural diagram of a heat dissipation device in an embodiment of the present invention.

Fig. 2 is a flow chart of a method for preparing a heat sink in an embodiment of the present invention.

Fig. 3 is a schematic diagram of a method for forming an aluminum titanium nitride layer in an embodiment of the present invention.

Fig. 4 is a schematic view of the use of the heat dissipation device of the present invention.

【Detailed ways】

Please refer to FIG. 1 first, which is a schematic structural diagram of a heat sink 5 according to a preferred embodiment of the present invention, which includes a base 1, an aluminum titanium nitride layer 2 formed on the base 1, and an aluminum titanium nitride layer 2 formed on the aluminum titanium nitride layer. The catalyst layer 3 is formed on the carbon nanotubes 4 on the catalyst layer 3 .

Please refer to FIG. 2 and FIG. 3 together for a detailed description of the manufacturing method of the heat sink 5 provided by the preferred embodiment of the present invention.

The preparation method of the heat sink 5 of the preferred embodiment of the present invention comprises the following steps: step 11, providing a base 1; step 12, forming an aluminum titanium nitride layer 2 on the base 1; step 13, forming an aluminum nitride layer on the aluminum nitride A catalyst layer 3 is formed on the titanium layer 2 ; step 14 , growing carbon nanotubes 4 on the catalyst layer 3 .

Each step will be described in detail below in conjunction with the embodiments.

Step 11, providing a base 1 . In this embodiment, a copper plate is selected as the base 1 .

Step 12 , forming a TiAlN layer 2 on the base 1 . As shown in FIG. 3, titanium aluminum nitride (TiAlN) can be formed by evaporation or sputtering. The evaporation method is to heat the material to be deposited (Ti and Al metal) to a high temperature under high vacuum conditions, evaporate it, and deposit it on the surface of the substrate in a nitrogen environment, thereby forming a TiAlN evaporation layer. The sputtering method uses plasma-generated ions to bombard the target (ie, Ti and Al metals), so that the atoms of the target are excited, escape and deposit on the surface of the substrate, and nitrogen gas is introduced at the same time to form a TiAlN sputtering layer.

Step 13 , forming a catalyst layer 3 on the titanium aluminum nitride layer 2 . First, the catalyst metal is formed on the surface of the aluminum titanium nitride layer 2 on the base 1 by electron beam evaporation deposition method, thermal deposition method or sputtering method; then, the base 1 deposited with the catalyst metal is placed in the air In the heat treatment at 300-400°C for about 10 hours, the catalyst metal is oxidized into catalyst oxide particles; finally, the catalyst oxide particles are reduced into nano-scale catalyst particles with a reducing gas, so that on the surface of the aluminum titanium nitride layer 2 A catalyst layer 3 composed of nanoscale catalyst particles is formed. Wherein, the catalyst metal includes one or more of nickel, iron, cobalt and alloys thereof, iron is selected in this embodiment; the deposition thickness of the catalyst metal is several nanometers to hundreds of nanometers, preferably 5 nanometers; The inert gas can be hydrogen or ammonia, etc.

Step 14 , growing carbon nanotubes 4 on the catalyst layer 3 . Firstly, the base 1 with the titanium aluminum nitride layer 2 and the catalyst layer 3 is put into a reaction chamber (not shown in the figure), and a protective gas is introduced into the reaction chamber and heated to a predetermined temperature. Wherein, the protective gas can be an inert gas such as argon or helium or nitrogen, and argon is used in this embodiment; the predetermined temperature is different due to the difference of the catalyst material, and when metal iron is selected as the catalyst metal, it is generally heated to 500-700°C, preferably 650°C. Then, the carbon source gas is introduced into the reaction chamber for reaction, and the carbon nanotubes 4 grow from the catalyst layer 3 . Wherein, the carbon source gas is a hydrocarbon, including acetylene, ethylene, etc., and acetylene is selected in this embodiment.

The metal itself has a crystalline structure with grain boundaries, and the grain boundaries are an excellent diffusion path for copper atoms. In addition, copper itself is a metal with a high diffusion coefficient, so it is easy to dissolve into in the catalytic metal layer. The present invention uses aluminum titanium nitride layer 2 as the diffusion barrier layer of copper atoms, which adds nitrogen atoms into metal aluminum and titanium through plasma treatment, and nitrogen atoms destroy the crystal structure of metal aluminum and titanium, thereby eliminating grain boundaries , effectively blocking the diffusion of copper atoms. Moreover, titanium aluminum nitride has a high melting point, is not miscible with copper even at high temperature, has a high thermal conductivity, and can ensure high heat dissipation efficiency of the heat dissipation device 5 . In addition, titanium aluminum nitride is resistant to oxidation at 1000°C and maintains its inherent properties. Even if a thin layer of aluminum oxide is formed on the titanium aluminum nitride layer 2 during the formation of the catalyst layer 3, the aluminum oxide is also stable at high temperatures. phase, and is a hindering layer that can effectively block the movement of atoms, so it can reduce the diffusion of copper atoms to the coal contact layer 3 and react with the catalyst particles therein, and also prevent the catalyst particles in the catalyst layer 3 from diffusing out and combining with copper atoms The thermal conductivity of alumina is also better, and its thermal conductivity is above 30W/mK. Therefore, the aluminum titanium nitride layer 2 of the heat dissipation device 5 in this embodiment can not only effectively prevent the diffusion of copper atoms, but also ensure high heat dissipation efficiency of the heat dissipation device 5 .

In addition, the heat dissipation device of the present invention may also include heat dissipation fins made of metals such as copper and aluminum, and its cross section may be U-shaped or L-shaped. one side.

Please refer to FIG. 4 , which is a schematic diagram of the use of the heat dissipation device 9 of the present invention. The heat generated by the heating element 8 is transferred to the base 1 through the carbon nanotube 4, the catalyst layer 3 and the aluminum nitride titanium layer 2, and then transferred from the base 1 to the cooling fins 7, and finally the base 1 and the cooling fins The sheet 7 dissipates heat to the surrounding air, thereby completing the heat dissipation performance of the heat dissipation device 9 . Moreover, since the carbon nanotubes 4, the catalyst layer 3 and the aluminum titanium nitride layer 2 all have excellent thermal conductivity, it can ensure that the heat generated by the heating element 8 is discharged in time, so that the heating element 8 can operate at a normal operating temperature. To ensure the quality of data processing, storage and transmission.

Claims (10)

1. A heat dissipation device, comprising: a heat dissipation base, which includes two opposite surfaces; it is characterized in that: an aluminum titanium nitride layer is formed on one of the surfaces of the heat dissipation base; a metal is deposited on the aluminum titanium nitride layer a catalyst layer; and carbon nanotubes are grown on the metal catalyst layer. 2 . The heat dissipation device according to claim 1 , further comprising heat dissipation fins formed on the other surface of the heat dissipation base. 3 . 3. The heat dissipation device according to claim 2, wherein the heat dissipation base and the heat dissipation fins are made of copper. 4. The method for preparing a heat dissipation device as claimed in claim 1, comprising the steps of: providing a heat dissipation base; forming an aluminum titanium nitride layer on a surface of the heat dissipation base; forming an aluminum titanium nitride layer on the aluminum titanium nitride layer A metal catalyst layer is formed; carbon nanotubes are grown on the metal catalyst layer. 5 . The manufacturing method of the heat dissipation device according to claim 4 , wherein the method of forming an aluminum titanium nitride layer on a surface of the heat dissipation base is a sputtering method or an evaporation method. 5 . 6 . The method for manufacturing a heat sink as claimed in claim 5 , wherein the sputtering method or evaporation method is carried out in a nitrogen environment. 7 . 7. The method for preparing a heat sink as claimed in claim 4, wherein the step of forming a metal catalyst layer on the aluminum titanium nitride layer comprises: forming the catalyst metal on the surface of the aluminum titanium nitride layer; The heat dissipation base of the catalytic metal is placed in the air and heat-treated at 300-400°C for about 10 hours to oxidize the catalytic metal into catalytic oxide particles; the catalytic oxide particles are reduced into nanoscale catalytic particles with reducing gas. 8 . The method for preparing a heat sink according to claim 7 , wherein the catalytic metal includes one or more of nickel, iron, cobalt and alloys thereof. 9 . The method for manufacturing a heat sink according to claim 7 , wherein the deposition method of the catalytic metal comprises an electron beam evaporation deposition method, a thermal deposition method or a sputtering method. 10 . The method for manufacturing a heat sink as claimed in claim 4 , wherein the growth of carbon nanotubes on the catalyst layer is achieved by chemical vapor deposition. 11 .

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