Copper nanorod-based thermal interface material (TIM)

Patent metadata

Field	Value
Publication number	US-9601406-B2
Application number	US-201313782893-A
Country	US
Kind code	B2
Filing date	Mar 1, 2013
Priority date	Mar 1, 2013
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A copper nanorod thermal interface material (TIM) is described. The copper nanorod TIM includes a plurality of copper nanorods having a first end thermally coupled with a first surface, and a second end extending toward a second surface. A plurality of copper nanorod branches are formed on the second end. The copper nanorod branches are metallurgically bonded to a second surface. The first surface may be the back side of a die. The second surface may be a heat spread or a second die. The TIM may include a matrix material surrounding the copper nanorods. In an embodiment, the copper nanorods are formed in clusters.

First claim

What is claimed is:

1. A thermal interface material, comprising:
a plurality of copper nanorods, each having a first end thermally coupled with a first surface and a second end extending toward a second surface, wherein the second surface is copper; and
a plurality of copper nanorod branches extending from each second end, wherein the copper nanorod branches have a Cu—Cu metallurgic bond to the second surface.

2. The thermal interface material of claim 1 , wherein the thermal interface material has a thermal resistivity less than 0.03 C-cm 2 /W.

3. The thermal interface material of claim 1 , wherein the copper nanorods have a diameter less than 20 μm.

4. The thermal interface material of claim 1 , wherein the copper nanorods have a length from 5 μm to 50 μm.

5. The thermal interface material of claim 1 , wherein the copper nanorods are spaced from 5 nm to 10 μm apart.

6. The thermal interface material of claim 1 , wherein 10% to 50% of a surface area of the first surface is occupied by copper nanorods.

7. The thermal interface material of claim 1 , wherein 10% to 50% of a volume between the first surface and the second surface is occupied by copper nanorods.

8. The thermal interface material of claim 1 , wherein the copper nanorods are clustered in a plurality of nanorod clusters.

9. The thermal interface material of claim 8 , wherein the nanorod clusters have an average diameter from 50 to 100 μm.

10. The thermal interface material of claim 8 , wherein the clusters have an average spacing from 50 to 100 μm.

11. The thermal interface material of claim 1 , further comprising a matrix material between the first surface and the second surface.

12. The thermal interface material of claim 1 , wherein the first surface is copper, and wherein the first ends are metallurgically bonded with the first surface.

13. The thermal interface material of claim 1 , wherein the copper nanorods have a <110> orientation along a central axis.

14. The thermal interface material of claim 1 , wherein the copper branches extend from <111> facets on the second end of the copper nanorods.

15. A method for thermally coupling a first surface and a second surface, comprising:
growing a plurality of copper nanorods from the first surface, wherein the copper nanorods have a first end thermally coupled with the first surface and a second end extending away from the first surface;
growing a plurality of copper nanorod branches on each second end; and
metallurgically bonding the second surface to the copper nanorod branches, wherein the second surface is copper wherein the copper nanorod branches have a Cu—Cu metallurgic bond to the second surface.

16. The method of claim 15 , further comprising, prior to growing a plurality of copper nanorods:
forming a patterning layer over the first surface; and
patterning the patterning layer to expose portions of the first surface.

17. The method of claim 15 , wherein metallurgically bonding the second surface to the copper nanorod branches comprises heating the nanorod branches and the second surface to a temperature less than 400° C.

18. The method of claim 15 , further comprising underfilling the remaining space between the first surface and the second surface with a matrix material.

19. The method of claim 15 , further comprising forming a nickel layer on the copper nanorods and copper nanorod branches to prevent oxidation.

20. The method of claim 15 , further comprising introducing a fluxing agent to remove oxide from the copper nanorods and copper nanorod branches.

21. The method of claim 15 , wherein the copper nanorods are grown by one of sputter deposition and vapor deposition.

Assignees

• Jha Chandra M
• Eid Feras
• Swan Johanna M
• Gupta Ashish
• Intel Corp

Inventors

• Jha Chandra M
• Eid Feras
• Swan Johanna M
• Gupta Ashish

Classifications

• H10W76/17

  characterised by their materials · CPC title

• H10W90/288

  characterised by arrangements for thermal management of the stacked chips · CPC title

• H10W90/20

  Configurations of stacked chips · CPC title

• H10W72/0198

  batch processes · CPC title

• H10W74/15

  on active surfaces of flip-chip devices, e.g. underfills · CPC title