CN100389492C

CN100389492C - Heat sink and method for making same

Info

Publication number: CN100389492C
Application number: CNB2003101176582A
Authority: CN
Inventors: 颜士杰
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2003-12-24
Filing date: 2003-12-24
Publication date: 2008-05-21
Anticipated expiration: 2023-12-24
Also published as: CN1632947A

Abstract

The present invention provides a heat sink which comprises a base, an aluminium nitride layer formed at one side of the base, a catalyze layer formed on the aluminium nitride layer, and a carbon nanotube formed on the catalyze layer. In addition, the present invention provides a preparation method of the heat sink, which comprises the following steps: providing the base which comprises two opposite sides; forming the aluminium nitride layer at one side of the base; forming the catalyze layer on the aluminium nitride layer; growing out the carbon nanotube on the catalyze layer. The present invention uses the aluminium nitride layer as a diffusion impervious layer. The diffusion impervious layer can effectively prevent the copper atoms in the base from diffusing to the catalyst layer and reacting with catalyst particles to influence the growth of the carbon nanotube. The higher thermal conductivity of the aluminum nitride can ensure high heat radiation efficiency of the heat sink.

Description

Heat abstractor and preparation method thereof

[technical field]

The present invention relates to a kind of heat abstractor and preparation method thereof, especially relates to heat abstractor of a kind of high cooling efficiency and preparation method thereof.

[background technology]

Along with developing rapidly of information industry, the deal with data ability of the heater element (as central processing unit and video card heater element) that electronic installation is inner set is also more and more strong.Yet, follow the lifting of heater element arithmetic speed, the heat of its generation also increases considerably.For described heat is discharged rapidly, heater element is moved under normal working temperature, to guarantee the quality of data processing, storage and transmission, on the surface of described heater element one heat abstractor is set usually.

Heat abstractor pedestal of the prior art adopts copper product to make (the copper conductive coefficient can reach 402W/mK) more, and carbon nano-tube is applied between heater element and heat abstractor pedestal as heat conducting element, because seamless, hollow tubular thing that the graphite linings that carbon nano-tube is a carbon atom to be formed is curled and formed, has excellent axial thermal conductivity, its conductive coefficient can reach 20000W/mK (be approximately copper product 50 times), can improve the heat conductivility between heater element and heat abstractor pedestal greatly, thereby improve the heat dispersion of integral heat dissipation means.

For obtaining to be formed on the carbon nano-tube on the heat abstractor, normally behind catalyst particles such as nickel deposited, iron, cobalt on the copper coin, again by the chemical vapour deposition technique carbon nano-tube.But, if direct catalyst particles such as nickel deposited, iron, cobalt on copper coin because the copper atom diffusivity is very good, very easily be diffused into catalyst layer and with wherein catalyst particle reaction, cause growing the carbon nano-tube that can be applicable to heat abstractor smoothly.

For solving the problem that the copper atom diffusion influences carbon nano tube growth, need be on copper coin evaporation or sputter one deck barrier layer are to stop the generation of copper atom diffusion phenomena in advance, titanium nitride (TiN) material commonly used in the manufacture of semiconductor is used on the barrier layer that proposes more at present.As disclosing chemical gas-phase method depositing titanium nitride and copper metal layer Damascus technics in No. the 03114708.9th, the Chinese patent application, described method is in a multi-cavity body vacuum equipment, successive sedimentation TiN barrier layer, Cu metallic film successively, and at H ₂-N ₂Carry out short annealing in the atmosphere, thereby obtain grain size and all well-proportioned barrier layer of distribution of resistance and Cu metallic film.

But, the TiN barrier layer that said method provides, because the conductive coefficient of TiN only is 30W/mK, relative copper (the copper conductive coefficient can reach 402W/mK) and carbon nano-tube (conductive coefficient can reach 20000W/mK), heat transfer rate is slow, thereby limits its radiating efficiency on the whole at heat abstractor.

In view of this, heat abstractor that a kind of high cooling efficiency is provided and preparation method thereof is real in necessary.

[summary of the invention]

Be the low problem of radiating efficiency that solves heat abstractor of the prior art, the purpose of this invention is to provide a kind of heat abstractor of high cooling efficiency.

Another object of the present invention provides the preparation method of above-mentioned heat abstractor.

For realizing purpose of the present invention, the invention provides a kind of heat abstractor, it comprises: the copper pedestal, be formed at described copper pedestal aln layer simultaneously, be formed at the catalyst layer on the described aln layer, be formed at the carbon nano-tube on the described catalyst layer.

Be to realize another object of the present invention, the invention provides a kind of preparation method of heat abstractor, it comprises the steps: to provide a copper pedestal that comprises relative two sides; One side at described copper pedestal forms an aln layer; On described aln layer, form a catalyst layer; On described catalyst layer, grow carbon nano-tube.

Compared with prior art, the present invention is as diffusion impervious layer with aln layer, described barrier layer can prevent effectively that not only the copper atom in the pedestal is diffused into catalyst layer, influence the growth of carbon nano-tube with the catalyst particle reaction, and the higher high cooling efficiency that also can guarantee heat abstractor of aluminium nitride conductive coefficient.

[description of drawings]

Fig. 1 is the structural representation of heat abstractor in the embodiment of the invention.

Fig. 2 is the formation method schematic diagram of aln layer in the embodiment of the invention.

Fig. 3 is the use schematic diagram of heat abstractor of the present invention.

Fig. 4 is preparation method's flow chart of heat abstractor in the embodiment of the invention.

[embodiment]

Please consulting Fig. 1 earlier, is the structural representation of the heat abstractor 5 of preferred embodiment of the present invention, and it comprises pedestal 1, is formed at the aln layer 2 of pedestal 1 one side, is formed at the catalyst layer 3 on the aln layer 2, is formed at the carbon nano-tube 4 on the catalyst layer 3.

See also Fig. 2 and Fig. 4, the preparation method of the heat abstractor 5 that preferred embodiment of the present invention provided is elaborated.

The preparation method of the heat abstractor 5 of preferred embodiment of the present invention may further comprise the steps: step 11 provides a pedestal 1; Step 12 forms an aln layer 2 in the one side of pedestal 1; Step 13 forms a catalyst layer 3 on aln layer 2; Step 14 grows carbon nano-tube 4 on catalyst layer 3.

Step 11 provides a pedestal 1.Select for use copper coin as pedestal 1 in the present embodiment, it comprises relative two sides.

Step 12 forms an aln layer 2 on pedestal 1.At first, by sputtering method or vapour deposition method deposition layer of aluminum film 6, its thickness is less than 100 dusts in pedestal 1 one side; Then, aluminium film 6 is carried out plasma treatment, aluminium film 6 is converted into aln layer 2 by nitrogen or ammonia.

Step 13 forms a catalyst layer 3 on aln layer 2.At first, catalyst metals is utilized methods such as electron beam vapor deposition method, heat deposition method or sputtering method be formed on aln layer 2 surfaces on the pedestal 1; Then, the pedestal 1 that deposits catalyst metals is positioned in the air,, makes catalyst metals be oxidized to the catalyst oxidation composition granule about 10 hours of 300～400 ℃ of heat treatments; At last, described catalyst oxidation composition granule is reduced into the nm-class catalyst particle with reducibility gas, thereby forms a catalyst layer 3 of forming by the nm-class catalyst particle on aln layer 2 surface.Wherein, catalyst metals comprises in nickel, iron, cobalt and the alloy thereof one or more, selects iron in the present embodiment for use; The deposit thickness of described catalyst metals is that several nanometers arrive the hundreds of nanometer, is preferable with 5 nanometers; Reducibility gas can be hydrogen or ammonia etc.

Step 14 grows carbon nano-tube 4 on catalyst layer 3.At first, the pedestal 1 that will have aln layer 2 and catalyst layer 3 is put into reative cell (figure does not show), feeds protective gas and be heated to a predetermined temperature in reative cell.Wherein, described protective gas can be inert gas or nitrogen such as argon gas, helium, selects argon gas in the present embodiment for use; Described predetermined temperature when selecting for use metallic iron to be catalyst metals, then generally is heated to 500～700 ℃ because of the difference of catalyst material is different, is preferable with 650 ℃.Then, feed carbon source gas and react in reative cell, carbon nano-tube 4 grows from catalyst layer 3.Wherein, carbon source gas is hydrocarbon, comprises acetylene, ethene etc., selects acetylene in the present embodiment for use.

Metal have crystal boundary, and crystal boundary is a kind of fabulous diffusion path originally as crystalline texture for copper atom, add the metal that copper itself is a kind of high diffusion coefficient, therefore just dissolves in the catalyst metal layer at low temperatures easily very much.The present invention is with the diffusion impervious layer of aln layer 2 as copper atom in the pedestal, and it is to add nitrogen-atoms by plasma processing in metallic aluminium, and nitrogen-atoms destroys the crystal structure of metallic aluminium, thereby eliminates crystal boundary, effectively stops the diffusion of copper atom.And aluminium nitride has high-melting-point (its fusing point can reach 2450 ℃), even at high temperature also do not dissolve each other with copper, conductive coefficient is 80～260W/mK, can guarantee the high cooling efficiency of heat abstractor 5.In addition, aluminium nitride is down anti-oxidant and keep its proper property at 1000 ℃, even in the forming process of catalyst layer 3, on aln layer 2, generate the aluminium oxide thin layer, aluminium oxide at high temperature also belongs to stable phase, and be one can effectively intercept the barrier layer that atom moves, with wherein catalyst particle reaction, also can prevent from that catalyst particle in the catalyst layer 3 from diffusing out with copper atom in the pedestal simultaneously to combine and reacted away so can reduce that copper atom in the pedestal is diffused into catalyst layer 3; The heat conductivility of aluminium oxide is also preferable, and its conductive coefficient is more than 30W/mK.Thereby the aln layer 2 of the heat abstractor 5 of present embodiment not only can effectively prevent the copper atom diffusion in the pedestal, and can guarantee the high cooling efficiency of heat abstractor 5.

In addition, heat abstractor of the present invention can comprise that also by metal a plurality of radiating fins such as copper, aluminium, its section can be shapes such as U font, L font, and described a plurality of radiating fins can be formed at the another side of pedestal 1 by impact style.

Seeing also Fig. 3, is the use schematic diagram of heat abstractor 9 of the present invention.The heat that heater element 8 is produced is delivered to pedestal 1 through carbon nano-tube 4, catalyst layer 3 and aln layer 2, be delivered on the radiating fin 7 by pedestal 1 again, finally heat is dispersed on every side in the flow air, thereby finishes the heat dissipation of heat abstractor 9 by pedestal 1 and radiating fin 7.And, because carbon nano-tube 4, catalyst layer 3 and aln layer 2 all have good heat conductivility, can guarantee that the heat that heater element 8 is produced in time is discharged from, heater element 8 is moved under normal working temperature, to guarantee the quality of data processing, storage and transmission.

Claims

1. a heat abstractor comprises the copper pedestal, it is characterized in that: described heat abstractor also comprises the aln layer of the one side that is formed at described copper pedestal, is formed at the catalyst layer on the described aln layer, is formed at the carbon nano-tube on the described catalyst layer.

2. heat abstractor as claimed in claim 1 is characterized in that: described heat abstractor further comprises a plurality of radiating fins, and described radiating fin is positioned at the another side of copper pedestal.

3. heat abstractor as claimed in claim 2 is characterized in that: described radiating fin is to be made by copper or aluminium.

4. the preparation method of heat abstractor as claimed in claim 1 is characterized in that comprising the steps: providing a copper pedestal that comprises relative two sides; One side at described copper pedestal forms an aln layer; On described aln layer, form a catalyst layer; On described catalyst layer, grow carbon nano-tube.

5. the preparation method of heat abstractor as claimed in claim 4 is characterized in that: the step that forms an aln layer in the one side of described copper pedestal comprises: at the one side deposition layer of aluminum film of copper pedestal; Described aluminium film is carried out plasma treatment, the aluminium film is converted into aln layer.

6. the preparation method of heat abstractor as claimed in claim 4 is characterized in that: the step that forms a catalyst layer on described aln layer comprises: catalyst metals is formed at the aln layer surface; The copper pedestal that deposits catalyst metals is positioned in the air after the heat treatment, makes catalyst metals be oxidized to the catalyst oxidation composition granule; Described catalyst oxidation composition granule is reduced into the nm-class catalyst particle with reducibility gas.

7. the preparation method of heat abstractor as claimed in claim 4, it is characterized in that: the step that grows carbon nano-tube on described catalyst layer comprises: the copper pedestal is put into reative cell, feed carbon source gas and react in reative cell, carbon nano-tube grows from catalyst layer.

8. the preparation method of heat abstractor as claimed in claim 4, it is characterized in that: the another side at described copper pedestal is formed with a plurality of radiating fins.

9. the preparation method of heat abstractor as claimed in claim 8, it is characterized in that: described a plurality of radiating fins are the another sides that are formed at the copper pedestal by impact style.

10. the preparation method of heat abstractor as claimed in claim 8, it is characterized in that: described radiating fin is to be made by copper or aluminium.