Depositing carbon nanotubes onto substrate

• US 20100224354A1
• Filed: 03/08/2009
• Published: 09/09/2010
• Est. Priority Date: 03/08/2009
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Dooley, Kevin, Fenelon, Anna, Sheehan, Lynn, Sharma, Ratnesh Kumar, Escobar-Vargas, Sergio
• Granted Patent: US 8,323,439 B2
• Time in Patent Office: Days
• US Class Current: 165/185
• CPC Class Codes: B32B 2313/04 Carbon
• CPC Class Codes: B32B 2317/12 Paper, e.g. cardboard
• CPC Class Codes: B32B 2457/00 Electrical equipment
• CPC Class Codes: B32B 2553/00 Packaging equipment or accessories not otherwise provided for
• CPC Class Codes: B32B 37/025 Transfer laminating
• CPC Class Codes: F28F 21/02 of carbon, e.g. graphite
• CPC Class Codes: H01L 23/373 Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
• CPC Class Codes: H01L 24/29 of an individual layer connector
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 2924/078 Adhesive characteristics other than chemical
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/157 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: Y10T 29/4935 Heat exchanger or boiler making

Abstract

To deposit carbon nanotubes onto a substrate, an at least partially porous film is prepared so that a surface of the film has a layer of carbon nanotubes thereon. The film is positioned in relation to a surface of the substrate such that the surface of the film having the layer of carbon nanotubes is brought into contact with the surface of the substrate. Pressure is applied to the film to attach the film, including the layer of carbon nanotubes, to the surface of the substrate.

Claims

1. A method for depositing carbon nanotubes onto a substrate, comprising:

preparing an at least partially porous film so that a surface of the at least partially porous film has a layer of carbon nanotubes thereon;

positioning the at least partially porous film in relation to a surface of the substrate such that the surface of the at least partially porous film having the layer of carbon nanotubes is brought into contact with the surface of the substrate; and

,

applying pressure to the at least partially porous film to attach the at least partially porous film, including the layer of carbon nanotubes, to the surface of the substrate.

2. The method of claim 1, wherein preparing the at least partially porous film comprises:

dispersing a plurality of carbon nanotubes within a solution; and

,

depositing the carbon nanotubes within the solution onto the surface of the at least partially porous film.

3. The method of claim 2, wherein preparing the at least partially porous film further comprises introducing a surfactant to the solution prior to dispersing the carbon nanotubes within the solution.

4. The method of claim 2, wherein depositing the carbon nanotubes within the solution onto the surface of the at least partially porous film comprises employing vacuum filtration.

5. The method of claim 1, wherein applying pressure to the at least partially porous film comprises one of pressure-rolling, weighting, and clamping the at least partially porous film onto the surface of the substrate.

6. The method of claim 1, further comprising removably attaching the at least partially porous film to a backing sheet prior to positioning the at least partially porous film in relation to the surface of the substrate,

wherein applying pressure to the at least partially porous film comprises pressure-stamping the at least partially porous film onto the substrate via the backing sheet.

7. The method of claim 6, wherein attaching the at least partially porous film to the backing sheet comprises:

wetting a surface of the backing sheet with a solvent; and

,

bringing the surface of the backing sheet into contact with a second surface of the at least partially porous film such that the second surface of the at least partially porous film adheres to the surface of the backing sheet,

wherein the second surface of the at least partially porous film is opposite the surface of the at least partially porous film having the layer of carbon nanotubes.

8. The method of claim 1, further comprising removing the at least partially porous film from the surface of the substrate such that the layer of carbon nanotubes remains attached to the surface of the substrate.

9. The method of claim 8, wherein removing the at least partially porous film from the surface of the substrate such that the layer of carbon nanotubes remains attached to the surface of the substrate comprises soaking the surface of the substrate, including the at least partially porous film attached to the surface of the substrate, within a solvent.

10. The method of claim 1, further comprising preparing the surface of the substrate to promote adhesion of the layer of carbon nanotubes thereto, prior to positioning the at least partially porous film in relation to the surface of the substrate.

11. The method of claim 10, wherein preparing the surface of the substrate comprises:

soaking the surface of the substrate in one or more of an acid, a solvent, and a silane-coupling agent (SCA); and

,

rinsing the surface of the substrate to remove any residual acid, solvent, or SCA from the surface of the substrate.

12. A method for depositing carbon nanotubes onto a heat sink, comprising:

dispersing a plurality of carbon nanotubes within a solution;

vacuum filtrating the carbon nanotubes through a cellulose film to apply the carbon nanotubes as a layer onto a surface of the cellulose film;

positioning the cellulose film in relation to a surface of the heat sink such that the surface of the cellulose film having the layer of carbon nanotubes is brought into contact with the surface of the heat sink;

attaching the cellulose film, including the layer of carbon nanotubes, to the surface of the heat sink by one of;

pressure-rolling, weighting, or clamping the cellulose film onto the surface of the heat sink;

pressure-stamping the cellulose film as previously removably attached to a backing sheet onto the surface of the heat sink via the backing sheet;

soaking the surface of the heat sink, including the cellulose film attached to the surface of the heat sink, within a solvent to remove the cellulose film from the surface of the heat sink such that the layer of carbon nanotubes remains attached to the surface of the heat sink.

13. An apparatus comprising:

a substrate having a surface;

a removable at least partially porous film having a surface; and

,

a layer of carbon nanotubes attached to the surface of the substrate on one side and to the removable at least partially porous film on another side,

wherein the at least partially porous film is adapted such that removal of the removable at least partially porous film results in the layer of carbon nanotubes remaining attached to the surface of the substrate.

14. The apparatus of claim 13, wherein the substrate is a metal substrate.

15. The apparatus of claim 13, wherein the substrate is a heat sink.

16. The apparatus of claim 13, wherein the removable at least partially porous film is a cellulose film.

17. The apparatus of claim 13, wherein the removable at least partially porous film is one of:

a cellulose acetate film, a nitrocellulose mixed ester film, and a polycarbonate membrane film.

18. The apparatus of claim 13, wherein the removable at least partially porous film is adapted to being removal being immersion within a solvent.

19. The apparatus of claim 18, wherein the solvent is acetone.

20. The apparatus of claim 13, wherein the removable at least partially porous film is adapted to protect the layer of carbon nanotubes on the substrate during transportation of the substrate.