System and method for cooling digital mirror devices

Patent metadata

Field	Value
Publication number	US-10629515-B2
Application number	US-201615384411-A
Country	US
Kind code	B2
Filing date	Dec 20, 2016
Priority date	Dec 20, 2016
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

A cooling system comprising of a coolant manifold, a heat sink configured to fit in the coolant manifold, a plurality of cooling fins formed in the heat sink, and a coolant configured to flow through the coolant manifold to the heat sink. Diamond shaped pin fins associated with the heat sink create a series of divergent fluid paths for the cooling fluid that helps to create turbulence and improved heat transfer.

First claim

What is claimed is:

1. A cooling system for a digital micromirror device, said cooling system comprising:
a digital micromirror device comprising a digital micromirror array that directs light form an imaging laser diode array to an imaging path and onto media at an image plane;
a coolant manifold configured to accept a heat sink in thermal communication with said digital micromirror device, wherein said heat sink is configured to fit in said coolant manifold and wherein said heat sink is spring loaded by a plurality of springs that provide for a spring load that facilitates a thermal connection to a surface of the digital micromirror device and wherein as an incident energy from said imaging laser diode array increases a temperature of said digital micromirror device, heat is conducted away from said digital micromirror device through said heat sink;
a series of bushings that isolate said spring load from a ground to prevent electrical shorting, and wherein said spring load overcomes strain forces;
a plurality of fins and at least one pillar formed in said heat sink, wherein said at least one pillar serves as a heat conducting medium between said digital micromirror device and at least one fin among said plurality of fins; and
a coolant configured to flow through said coolant manifold to said heat sink.

2. The system of claim 1 further comprising: a thermal grease configured on a heating block associated with said coolant manifold and comprising a thin thermal grease layer in a range of 5 um to 12 um thick, wherein said thermal grease is applied to an interface between said at least one pillar and said digital micromirror device to facilitate said thermal connection to said surface of said digital micromirror device, and wherein said thermal grease comprises a non-conductive thermal grease.

3. The system of claim 1 wherein:
at least one fin among said plurality of fins comprises at least one of:
a pin fin shaped in a diamond pattern that facilitates a series of divergent fluid paths for said coolant;
a tubular shaped cooling fin;
a teardrop-shaped fin that promotes a reduction in friction losses; and
a micro-pillar.

4. The system of claim 3 wherein said coolant further comprises at least one of: a fully-fluorinated liquid and a two-phase refrigerant.

5. The system of claim 4 further comprising:
an inlet valve for introducing said coolant into said coolant manifold; and
an outlet valve for allowing said coolant to exit said coolant manifold wherein said coolant is circulated through said coolant manifold.

6. The system of claim 4 further comprising: a chip housing in thermal contact with said heat sink, wherein the chip housing maintains the digital micromirror device.

7. The system of claim 6 further comprising: a closed cell foam surrounding said heat sink configured to prevent condensation in said heat sink and around said heat sink and said digital micromirror device array.

8. A cooling system for a digital micromirror device, said cooling system comprising:
a digital micromirror chip comprising a digital micromirror device that includes a mirror array that directs light from a laser diode array to an imaging path and onto media at an image plane;
a coolant manifold configured to accept a heat sink in thermal communication with said digital micromirror device, wherein said heat sink is configured to fit in said coolant manifold and wherein said heat sink is spring loaded by a plurality of springs that provide for a spring load that facilitates a thermal connection to a surface of the digital micromirror device and wherein as an incident energy from said imaging laser diode array increases a temperature of said digital micromirror device, heat is conducted away from said digital micromirror device through said heat sink;
a series of bushings that isolate said spring load from a ground to prevent electrical shorting, and wherein said spring load overcomes strain forces;
a plurality of fins and at least one pillar formed in said heat sink, wherein said at least one pillar serves as a heat conducting medium between said digital micromirror device and at least one fin among said plurality of fins; and
a coolant configured to flow in an electrically insulated fluid path through said coolant manifold to said heat sink.

9. The system of claim 8 further comprising: a thermal grease configured on a heating block associated with said coolant manifold and comprising a thin thermal grease layer in a range of 5 um to 12 um thick, wherein said thermal grease is applied to an interface between said at least one pillar and said digital micromirror device to facilitate said thermal connection to said surface of said digital micromirror device, and wherein said thermal grease comprises a non-conductive thermal grease.

10. The system of claim 9 wherein:
at least one fin among said plurality of fins comprises at least one of:
a pin fin shaped in a diamond pattern fin that facilitates a series of divergent fluid paths for said coolant;
a tubular shaped cooling fin;
a teardrop-shaped fin that promote a reduction in friction losses; and
a micro-pillar.

11. The system of claim 10 wherein said coolant further comprises at least one of: a fully-fluorinated liquid and a two-phase refrigerant.

12. The system of claim 11 further comprising:
an inlet valve for introducing said coolant into said coolant manifold; and
an outlet valve for allowing said coolant to exit said coolant manifold wherein said coolant is circulated through said coolant manifold.

13. The system of claim 11 further comprising: a chip housing in thermal contact with said heat sink.

14. The system of claim 13 further comprising: a closed cell foam surrounding said heat sink configured to prevent condensation in said heat sink and around said heat sink and said digital micromirror device array.

15. A method of cooling a digital micromirror device, said method comprising:
providing a digital micromirror device comprising a digital micromirror device mirror array;
forming a heat sink in a coolant manifold that is configured to accept said heat sink;
placing a heat sink in thermal communication with said digital micromirror device, wherein said heat sink is spring loaded by a plurality of springs that provide for a spring load that facilitates a thermal connection to a surface of the digital micromirror device, wherein as an incident energy from an imaging laser diode array increases a temperature of said digital micromirror device, heat is conducted away from said digital micromirror device through said heat sink;
isolating said spring load from a ground with a series of bushings to prevent electrical shorting, wherein said spring load overcomes strain forces;
distributing a plurality of fins and at least one pillar among a plurality of pillars in said heat sink, wherein said at least one pillar serves as a heat conducting medium between said digital micromirror device and at least one fin among said plurality of fins; and
circulating a coolant through said coolant manifold to said heat sink.

16. The method of claim 15 further comprising: applying a thermal grease comprising a thin thermal grease layer in a range of 5 um to 12 um thick on a heating block associated with said coolant manifold, wherein said thermal grease is applied to an interface between said at least one pillar and said digital micromirror device to facilitate said thermal connection to said surface of said digital micromirror device, and wherein said thermal grease comprises a non-conductive thermal grease.

17. The meth

Assignees

• Xerox Corp

Inventors

• Leighton Roger G
• Adiletta Mark A
• Atwood Christopher D
• Dergham Ali R
• Zirilli Francisco
• Redding Gary D
• Nystrom Peter J

Classifications

• G02B26/0833

  the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B) · CPC title

• G02B7/1815

  with cooling or heating systems (cooling arrangements for laser mirrors H01S3/0401) · CPC title

• H01L23/473 Primary

  Electricity · mapped topic

• H10W40/47 Primary

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