Heat spreaders fabricated from metal nanoparticles

Patent metadata

Field	Value
Publication number	US-10695872-B2
Application number	US-201615065760-A
Country	US
Kind code	B2
Filing date	Mar 9, 2016
Priority date	Mar 11, 2015
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

Heat spreaders can help promote heat distribution at the surface of a heat sink. However, overly isotropic or anisotropic heat conduction through heat spreaders can limit their effectiveness. Heat spreaders providing for lateral distribution of heat can include a tapered structure containing a metal-diamond composite. The metal-diamond composite includes a continuous metallic phase and a plurality of micron-scale diamond particles located in spaced apart regions of the continuous metallic phase. An interlayer containing the continuous metallic phase but lacking micron-scale diamond particles is disposed between each of the spaced apart regions, and the metal-diamond composite increases in lateral size in a direction of increased tapering. Heat spreaders can be formed by disposing a first mixture containing micron-scale diamond particles and metal nanoparticles in first regions that are vertically spaced apart from each other, and at least partially fusing the metal nanoparticles to form a tapered structure.

First claim

What is claimed is the following:

1. A heat spreader comprising:
a tapered structure comprising a metal-diamond composite;
wherein the metal-diamond composite comprises a continuous metallic phase and a plurality of micron-scale diamond particles dispersed through the continuous metallic phase in spaced apart regions of the continuous metallic phase;
wherein an interlayer comprising the continuous metallic phase but lacking micron-scale diamond particles is disposed between each of the spaced apart regions;
wherein the metal-diamond composite increases in lateral size in a direction of increased tapering;
wherein a first outer surface of the tapered structure is spaced apart from and is located opposite to a second outer surface of the tapered structure; and
wherein the first outer surface of the tapered structure is smaller than the second outer surface of the tapered structure.

2. The heat spreader of claim 1 , wherein the plurality of micron-scale diamond particles range between about 200 microns and about 250 microns in size.

3. The heat spreader of claim 1 , wherein the metal-diamond composite comprises about 40% to about 70% micron-scale diamond particles by volume.

4. The heat spreader of claim 1 , wherein the tapered structure comprises a plurality of stepped tiers.

5. The heat spreader of claim 1 , wherein the continuous metallic phase has a grain size of about 250 nm or less.

6. The heat spreader of claim 1 , wherein the continuous metallic phase comprises copper.

7. The heat spreader of claim 1 , wherein the continuous metallic phase further comprises a carbide-forming additive.

8. The heat spreader of claim 1 , wherein the interlayers further comprise nanodiamond particles, a plurality of fibers, or any combination thereof disposed in the continuous metallic phase.

9. The heat spreader of claim 8 , wherein the plurality of fibers are oriented laterally in the interlayers.

10. The heat spreader of claim 8 , wherein the interlayers range between about 20 microns and about 500 microns in thickness.

11. A system comprising:
a heat source;
a heat sink; and
a heat spreader extending between the heat source and the heat sink and bonded thereto;
wherein the heat spreader comprises:
a tapered structure comprising a metal-diamond composite;

wherein the metal-diamond composite comprises a continuous metallic phase and a plurality of micron-scale diamond particles dispersed through the continuous metallic phase in spaced apart regions of the continuous metallic phase;
wherein an interlayer comprising the continuous metallic phase but lacking micron-scale diamond particles is disposed between each of the spaced apart regions; and
wherein the metal-diamond composite increases in lateral size from the heat source to the heat sink.

12. The system of claim 11 , wherein the plurality of micron-scale diamond particles range between about 200 microns and about 250 microns in size.

13. The system of claim 11 , wherein the metal-diamond composite comprises about 40% to about 70% micron-scale diamond particles by volume.

14. The system of claim 11 , wherein the tapered structure comprises a plurality of stepped tiers.

15. The system of claim 11 , wherein the continuous metallic phase comprises copper.

16. The system of claim 11 , wherein the interlayers further comprise nanodiamond particles, a plurality of fibers, or any combination thereof disposed in the continuous metallic phase.

17. The system of claim 16 , wherein the interlayers range between about 20 microns and about 500 microns in thickness.

Assignees

• Lockheed Corp

Inventors

• Zinn Alfred A
• Iyer Jyotsna
• Hsu Ike C

Classifications

• H10W40/258

  Metallic materials (H10W40/254, H10W40/257, H10W40/255, H10W40/251, H10W40/253 take precedence) · CPC title

• H10W40/254

  Diamond · CPC title

• H10W40/228

  the projecting parts being wire-shaped or pin-shaped · CPC title

• H10W40/22

  characterised by their shape, e.g. having conical or cylindrical projections · CPC title

• H10W40/10

  Arrangements for heating · CPC title