# US 2018/0322995 A1 · Apparatus and method for passive cooling of electronic devices

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- Number: US 2018/0322995 A1
- Document ID: US20180322995A1
- Status: Published application
- Kind: A1
- Application number: 15/584,755
- Filed: 2017-05-02
- Published: 2018-11-08
- Earliest claimed: 2017-05-02
- Assignees: General Electric Company
- Applicants: General Electric Company
- Inventors: Joo Han Kim; Nicholas Ernest Williams; Ning Liu; Predrag Hadzibabic; Lawrence Joseph Hannaford
- Web page: https://patentgrep.com/patent/US20180322995A1

## CPC

- H01F 27/18: by evaporating liquids
- F28D 15/0241: {the tubes being flexible}
- F28D 15/043: {forming loops, e.g. capillary pumped loops}
- H01F 27/008: {with temperature compensation}
- H01F 27/10: Liquid cooling
- H01F 27/20: Cooling by special gases or non-ambient air
- H05K 7/20336: {Heat pipes, e.g. wicks or capillary pumps}
- H05K 7/20936: {Liquid coolant with phase change}
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general)
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS

## Abstract

Methods and apparatuses for cooling an electronic device assembly having a heat producing are described. An electronic device assembly includes a heat dissipation member and a dielectric two-phase heat transfer device. The dielectric heat transfer device has an evaporator region thermally attached to a hot region of the heat producing component and a condenser region thermally attached to the heat dissipation member. The dielectric two-phase heat transfer device is fabricated from a dielectric material.

## Claims

### Claim 1

An electronic device assembly comprising:
a heat dissipation member; and
a dielectric two-phase heat transfer device comprising:
an evaporator region coupled in thermal communication with a hot region of a heat producing component; and
a condenser region coupled in thermal communication with said heat dissipation member, said dielectric two-phase heat transfer device fabricated from a dielectric material.

### Claim 2 (depends on 1)

The electronic device assembly in accordance with claim 1, wherein said dielectric two-phase heat transfer device further comprises a thermal channel that extends from said evaporator region to said condenser region.

### Claim 3 (depends on 2)

The electronic device assembly in accordance with claim 2 further comprising a working fluid in said thermal channel.

### Claim 4 (depends on 3)

The electronic device assembly in accordance with claim 3, wherein said working fluid fills less than an entire volume of said thermal channel and, wherein said thermal channel includes at least one of air and vapor bubbles separating portions of said working fluid.

### Claim 5 (depends on 3)

The electronic device assembly in accordance with claim 3, wherein said working fluid has a boiling point less than or equal to approximately 200 degrees Celsius.

### Claim 6 (depends on 3)

The electronic device assembly in accordance with claim 3, wherein said working fluid comprises at least one of water, ethanol, butane, and ammonia.

### Claim 7 (depends on 1)

The electronic device assembly in accordance with claim 1 further comprising a heat producing component, wherein said heat dissipation member comprises a core of said heat producing component.

### Claim 8 (depends on 1)

The electronic device assembly in accordance with claim 1, wherein said dielectric two-phase heat transfer device is formed as a sheet-like structure having a thickness that renders said dielectric two-phase heat transfer device flexible.

### Claim 9

A dielectric heat transfer bobbin for supporting concentric windings, said dielectric heat transfer bobbin comprising:
a base portion; and
a heat transfer wall coupled to said base portion, said heat transfer wall comprising a heat transfer circuit comprising a thermal channel, an evaporator region, and a condenser region, said thermal channel extending from said evaporator region to said condenser region, wherein said dielectric heat transfer bobbin is fabricated from a dielectric material.

### Claim 10 (depends on 9)

The dielectric heat transfer bobbin in accordance with claim 9, wherein said heat transfer wall comprises a dielectric two-phase heat transfer device.

### Claim 11 (depends on 10)

The dielectric heat transfer bobbin in accordance with claim 10, wherein said dielectric two-phase heat transfer device comprises a pulsating heat pipe.

### Claim 12 (depends on 9)

The dielectric heat transfer bobbin in accordance with claim 9 further comprising a working fluid in said thermal channel.

### Claim 13 (depends on 12)

The dielectric heat transfer bobbin in accordance with claim 12, wherein said working fluid fills less than an entire volume of said thermal channel and, wherein said thermal channel includes at least one of air and vapor bubbles separating portion of said working fluid.

### Claim 14 (depends on 12)

The dielectric heat transfer bobbin in accordance with claim 12, wherein said working fluid has a boiling point less than or equal to approximately 200 degrees Celsius.

### Claim 15 (depends on 12)

The dielectric heat transfer bobbin in accordance with claim 12, wherein said working fluid comprises at least one of water, ethanol, butane, and ammonia.

### Claim 16 (depends on 12)

The dielectric heat transfer bobbin in accordance with claim 12, wherein said dielectric material comprises one or more of mica, plastics, glass, porcelain, metal oxides, and polyetheretherketone.

### Claim 17

A method of cooling an electronic device assembly including a heat producing component having a hot region, said method comprising:
forming a flexible dielectric two-phase heat transfer device from a dielectric material, the flexible dielectric two-phase heat transfer device including an evaporator region and a condenser region;
thermally coupling the evaporator region to the hot region of the heat producing component; and
thermally coupling the condenser region to a heat dissipation member.

### Claim 18 (depends on 17)

The method in accordance with claim 17, wherein forming a flexible dielectric two-phase heat transfer device comprises forming a thermal channel within the flexible dielectric two-phase heat transfer device, the thermal channel extending from the evaporator region to the condenser region.

### Claim 19 (depends on 18)

The method in accordance with claim 18 further comprising adding a working fluid to the thermal channel, wherein the working fluid fills less than an entire volume of the thermal channel, such that the thermal channel includes at least one of air and vapor bubbles separating portion of the working fluid.

### Claim 20 (depends on 17)

The method in accordance with claim 17, wherein thermally coupling the evaporator region to the hot region of the heat producing component comprises bending the flexible dielectric two-phase heat transfer device around at least a portion of the heat producing component.