IP Library › Granted Patent US 12,426,206
Granted Patent B2
US 12,426,206 · App. 18/138,566 · Granted Sep 23, 2025

Immersion cooling with water-based fluid using nano-structured coating

Inventors: Nenad Miljkovic (Urbana, IL); Thomas Foulkes (Terre Haute, IN); Patrick Birbarah (Lacrosse, WI); Tarek Gebrael (Champaign, IL); Andrew Stillwell (Champaign, IL); Robert Pilawa-Podgurski (Alameda, CA)
Assignee: The Board of Trustees of the University of Illinois
H05K7/203C23C16/401C23C16/463C23C16/56H01L21/02126H01L21/02203H01L21/02271H05K1/0203H01L23/44H05K7/20818H05K2201/0179
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Quick Facts
Patent No.
US 12,426,206
App. No.
18/138,566
Granted
Sep 23, 2025
Kind
B2
Abstract

A cooling system includes a container having a water-based fluid in which are immersed printed circuit boards (PCBs). One or more high-thermal electrical components are disposed on the PCBs. A condenser causes water vapor generated by the one or more high-thermal electrical components to condense and passively return to the water-based fluid. A nano-engineered coating is deposited over the one or more high-thermal electrical components that includes an electrical insulation coating of between two to 25 microns in thickness deposited on the one or more high-thermal electrical components. A metallic nano-layer comprising a porous metallic nano-structure deposited on the electrical insulation coating.

Claims (35)

1. A cooling system comprising:

a container having a water-based fluid in which are immersed printed circuit boards (PCBs), wherein one or more high-thermal electrical components are disposed on the PCBs;

a condenser to cause water vapor generated by the one or more high-thermal electrical components to condense and passively return to the water-based fluid; and

a nano-engineered coating that covers an outside and top portion of the one or more high-thermal electrical components, wherein the nano-engineered coating comprises:

an electrical insulation coating of between two to 25 microns in thickness deposited on the one or more high-thermal electrical components; and

a metallic nano-layer comprising a porous metallic nano-structure deposited on the electrical insulation coating.

2. The cooling system of claim 1 , wherein the electrical insulation coating is a dielectric comprising one of silicon dioxide, silicon nitride, Parylene C, Parylene HT®, or Parylene N.

3. The cooling system of claim 1 , wherein the porous metallic nano- structure comprises one of copper or copper oxide.

4. The cooling system of claim 1 , wherein the water-based fluid comprises one of deionized water or a mixture of water and ethylene glycol.

5. The cooling system of claim 1 , wherein the water-based fluid includes a non-ionic surfactant.

6. The cooling system of claim 1 , wherein the one or more high-thermal electrical components comprise a bottom-cooled power transistor device having at least one thermal pad disposed on a back of a PCB opposite from the bottom-cooled power transistor device, the PCB includes through-hole vias between the bottom-cooled power transistor and the thermal pad, and wherein the nano-engineered coating is also deposited on the thermal pad.

7. A cooling system comprising:

a central cooling line that circulates a water-based fluid in a loop to cool mechanical and electrical components of a machine;

an injector coupled to the central cooling line and adapted to force the water-based fluid past printed circuit boards (PCBs) on which are disposed one or more high-thermal electrical components;

an output coupled to the central cooling line to recycle vapor and residual water-based fluid exiting the PCBs; and

a nano-engineered coating that covers an outside and top portion of the one or more high-thermal electrical components, wherein the nano-engineered coating comprises:

an electrical insulation coating of between two to 25 microns in thickness deposited on the one or more high-thermal electrical components; and

a metallic nano-layer comprising a porous metallic nano-structure deposited on the electrical insulation coating.

8. The cooling system of claim 7 , wherein the electrical insulation coating is a dielectric comprising one of silicon dioxide, silicon nitride, Parylene C, Parylene HT®, or Parylene N.

9. The cooling system of claim 7 , wherein the porous metallic nano-structure comprises one of copper or copper oxide.

10. The cooling system of claim 7 , wherein the water-based fluid comprises one of deionized water or a mixture of water and ethylene glycol.

11. The cooling system of claim 7 , wherein the water-based fluid includes a non-ionic surfactant.

12. The cooling system of claim 7 , wherein the one or more high-thermal electrical components comprise a bottom-cooled power transistor device having at least one thermal pad disposed on a back of a PCB opposite from the bottom-cooled power transistor device, the PCB includes through-hole vias between the bottom-cooled power transistor and the thermal pad, and wherein the nano-engineered coating is also deposited on the thermal pad.

13. An apparatus comprising:

a printed circuit board (PCB) having one or more power electronic components disposed on the PCB;

an electrical insulation coating that covers an outside and top portion of the one or more power electronic components relative to the PCB, wherein the electrical insulation coating is between two to 25 microns thick; and

a nano-layer comprising a porous metal-based nano-structure and that is deposited on the electrical insulation coating, wherein the nano-layer is a super-hydrophilic nucleating coating and is configured to be.

14. The apparatus of claim 13 , wherein the electrical insulation coating comprises a Parylene-based compound.

15. The apparatus of claim 13 , wherein the porous metal-based nano-structure comprises one of copper or copper oxide.

16. The apparatus of claim 13 , wherein a combination of the electrical insulation coating and the nano-layer deposited on the electrical insulation coating enable the PCB and the one or more power electronic components to be immersed in a water-based fluid to cool the one or more power electronic components while the one or more power electronic components are powered on.

17. The apparatus of claim 16 , wherein the water-based fluid comprises one of deionized water or a mixture of water and ethylene glycol.

18. The apparatus of claim 13 , further comprising:

the one or more power electronic components, which comprise a bottom-cooled power transistor device having at least one thermal pad disposed on a back of the PCB opposite from the bottom-cooled power transistor device; and

through-hole vias within the PCB to drive heat from the bottom-cooled power transistor device to the at least one thermal pad.

19. The apparatus of claim 13 , wherein the electrical insulation coating further covers the PCB.

Assignments (2)
EMPLOYMENT AGREEMENT AND REDACTED IDF Recorded Aug 22, 2023
From: FOULKES, THOMAS
To: THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS
Reel/Frame 064663/0538 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 22, 2023
From: MILJKOVIC, NENAD; BIRBARAH, PATRICK; GEBRAEL, TAREK; STILLWELL, ANDREW; PILAWA-PODGURSKI, ROBERT
To: THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS
Reel/Frame 063715/0928 →
Continuity (3)
Division 16948858 · Oct 2, 2020
Provisional Application 62910365 · Oct 3, 2019
Related Publication 20230332293A1 · Oct 19, 2023
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