Coating process for laser heat sinks

Patent metadata

Field	Value
Publication number	US-9825428-B2
Application number	US-201615271773-A
Country	US
Kind code	B2
Filing date	Sep 21, 2016
Priority date	Sep 25, 2015
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

In various embodiments, passivation layers are deposited on internal surfaces of cooling channels defined within heat sinks for electronic devices such as laser beam emitters, the passivation layers retarding or substantially preventing erosion and/or corrosion of the heat sinks.

First claim

What is claimed is:

1. A method of heat sink preparation, the method comprising:
providing a plurality of heat sinks each defining a different aperture fluidly connected to one or more hollow cooling channels defined within the heat sink, each cooling channel having an internal surface, wherein each of the heat sinks is configured to be separately placed in thermal contact with a different laser beam emitter for thermal management thereof;
providing a bottom manifold having an internal passage fluidly connected to (i) a gas inlet, (ii) a gas outlet, and (iii) a plurality of openings, each of the openings being positioned at a different distance away from the gas inlet, wherein the bottom manifold comprises a plurality of baffles therewithin each configured to direct gas flowing within the internal passage into a different one of the openings;
sealing a first surface of each heat sink against the bottom manifold such that the aperture of each heat sink is aligned with a different one of the openings;
flowing two or more gaseous precursors (a) through the gas inlet, (b) into each of the heat sinks through the aperture thereof, different ones of the baffles directing the two or more gaseous precursors into different ones of the apertures via different ones of the openings in the bottom manifold, (c) back out of each of the heat sinks through the aperture thereof, and (d) out of the gas outlet to thereby form a coating on the internal surface of the one or more cooling channels of each heat sink; and
after formation of the coating, (i) separating each heat sink from the bottom manifold and (ii) placing each heat sink in thermal contact with a different laser beam emitter.

2. The method of claim 1 , wherein the coating comprises at least one of TiO 2 , SiO 2 , or Al 2 O 3 .

3. The method of claim 1 , wherein the aperture of each of the heat sinks extends through the entire thickness of the heat sink, and further comprising, before flowing the precursors, sealing a second surface of each heat sink, opposite the first surface, with one or more top manifolds, and
further comprising removing the one or more top manifolds from all of the heat sinks prior to placing each heat sink in thermal contact with a different laser beam emitter.

4. The method of claim 3 , wherein the one or more top manifolds is a single top manifold sealed to a plurality of heat sinks.

5. The method of claim 3 , wherein (i) the one or more top manifolds comprises a plurality of top manifolds, and (ii) a different, discrete top manifold is sealed to each of the heat sinks.

6. The method of claim 1 , wherein the gaseous precursors are flowed sequentially.

7. The method of claim 1 , wherein sealing the first surface of each heat sink against the bottom manifold comprises disposing at least one of an o-ring or a gasket therebetween.

8. The method of claim 1 , further comprising:
sensing a flow parameter proximate the gas outlet; and
controlling a deposition parameter based at least on the sensed deposition parameter.

9. The method of claim 8 , wherein the flow parameter comprises at least one of a flow rate or a composition of at least one of the precursors.

10. The method of claim 8 , wherein the deposition parameter comprises at least one of (i) initiation of flow of at least one precursor, (ii) termination of flow of at least one precursor, (iii) flow rate of at least one precursor, or (iv) temperature applied to the heat sinks.

11. The method of claim 1 , further comprising, after formation of the coating:
supplying power to one of the laser beam emitters, whereby the laser beam emitter emits one or more laser beams; and
flowing a cooling fluid into the cooling channels defined within the heat sink in thermal contact with the laser beam emitter, whereby the coating retards or substantially prevents corrosion and/or erosion of the heat sink.

12. The method of claim 11 , wherein the laser beam emitter comprises a diode bar configured to emit a plurality of laser beams.

13. The method of claim 1 , wherein each heat sink is formed of multiple discrete layers cooperatively defining the hollow cooling channels within the heat sink.

14. The method of claim 1 , wherein a portion of each of the gaseous precursors flows through the gas inlet, through the bottom manifold, and out of the gas outlet without entering any of the heat sinks.

15. The method of claim 1 , further comprising heating the heat sinks during formation of the coating.

16. The method of claim 1 , further comprising heating the heat sinks and the bottom manifold during formation of the coating.

17. A method of heat sink preparation, the method comprising:
providing a plurality of heat sinks each defining two apertures, each aperture (i) having an internal surface, (ii) being fluidly connected to one or more hollow cooling channels defined within the heat sink, and (iii) extending through an entire thickness of the heat sink, wherein (a) each cooling channel has an internal surface and (b) each of the heat sinks is configured to be separately placed in thermal contact with a different laser beam emitter for thermal management thereof;
providing a bottom manifold having an internal passage fluidly connected to (i) a gas inlet, (ii) a gas outlet, and (iii) two openings;
sealing a first surface of a first heat sink against the bottom manifold such that each aperture of the first heat sink is aligned with a different one of the openings of the bottom manifold;
stacking one or more additional heat sinks over the first heat sink such that their apertures are aligned with the apertures of the first heat sink, each heat sink being sealed to any heat sink thereabove and therebelow;
providing a top manifold having an internal passage fluidly connected to two openings;
sealing the top manifold over the stack of heat sinks such that each aperture of the topmost heat sink is aligned with a different one of the openings of the top manifold;
flowing two or more gaseous precursors through the gas inlet, into a first aperture of each of the heat sinks, into one opening of the top manifold, through the top manifold, out of the other opening of the top manifold, into a second aperture of each of the heat sinks, and out of the gas outlet to thereby form a coating on the internal surface of the one or more cooling channels of each heat sink;
after formation of the coating, (i) separating the top manifold from the heat sinks, (ii) separating the bottom manifold from the heat sinks, and (iii) separating each of the heat sinks from the other heat sinks; and
thereafter, placing each heat sink in thermal contact with a different laser beam emitter.

18. The method of claim 17 , wherein the coating comprises at least one of TiO 2 , SiO 2 , or Al 2 O 3 .

19. The method of claim 17 , wherein sealing the first surface of the first heat sink against the bottom manifold comprises disposing at least one of an o-ring or a gasket therebetween.

20. The method of claim 17 , wherein stacking the one or more additional heat sinks over the first heat sink comprises disposing at least one of an o-ring or a gasket between adjacent heat sinks.

21. The method of claim 17 , wherein sealing the top manifold over the stack of heat sinks comprises disposing at least one of an o-ring or a gasket therebetween.

22. The method of claim 17 , wherein the gaseous precursors are flowed sequentially.

23. The method of claim 17 , further comprising:
sensing a flow parameter pro

Assignees

• Huang Robin
• Chann Bien
• Tayebati Parviz
• Teradiode Inc

Inventors

• Huang Robin
• Chann Bien
• Tayebati Parviz

Classifications

• H01S5/02423 Primary

  Liquid cooling, e.g. a liquid cools a mount of the laser · CPC title

• C23C16/4583

  the substrate being supported substantially horizontally · CPC title

• C23C16/45555

  applied in non-semiconductor technology · CPC title

• H01S5/4025

  Array arrangements, e.g. constituted by discrete laser diodes or laser bar (H01S5/42 takes precedence) · CPC title

• H10W40/47

  by flowing liquids, e.g. forced water cooling · CPC title