US3673306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid heat transfer method and apparatus for semi-conducting devices
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1970-11-02
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Granted: 1972-06-27
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Expires: 1990-11-02
Abstract
Abstract There is disclosed the use of a heat pipe type thermal conductive path within a metallic housing such as a transistor can for a highly efficient cooling of high power semi-conductor devices which normally require large heat dissipation. An electrically non-conductive wick structure is provided which is formed, for example, from high purity silica glass cloth in a shape resembling a hollow ''''marshmallow'''' and which forms a liner for the entire transistor can. The wick contacts both the active surface of the semi-conductor device in the bottom of the can and the upper walls of the can. Prior to placing the can upon its mounting base, an appropriate amount of electrically nonconductive, non-polar working fluid such as high purity organic liquid is loaded so that it entirely fills or saturates only the wick like structure. The working fluid held within the wick is thus in immediate contact with the active surface of the semiconducting device. In operation, the surface of the semiconductor device serves as the evaporator section of the closed loop heat pipe. As fluid is caused to evaporate from this region, heat transfer and thus cooling of the device is effected. The vapor thus produced is recondensed over regions of the can which are at slightly cooler temperatures than the semiconductor device. The working fluid vapor thus provides an efficient heat transfer path to the entire radiating surface of the can in order to dissipate the thermal energy of concern.
Inventors
- 👤 Milton E Kirkpatrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:15
CPC Classifications
F; F28; F28D; F28D15/00; F28D15/02; F28D15/0266; F28D15/04; H; H10; H10W; H10W40/00; H10W40/70; H10W40/73
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
191 words
A package for a heat generating solid state electronic device having an active surface wherein heat is generated during operation of said device, comprising: a. base means to mechanically support said device at regions removed from said active surface; b. heat dissipating cover means forming with said base means a closed container housing said device and forming a vapor space adjacent to said device; c. electrically non-conductive capillary means on the interior surfaces of said container and in direct contact with the entire active surface of said solid state electronic device, said capillary means forming a closed flow path through which liquid may flow by capillary action; and d. an electrically non-conductive, non-polar working fluid in said capillary means, said working fluid having a boiling point such that it is evaporated from said active surface of said solid state electronic device to form a vapor which flows to the interior surfaces of said heat dissipating cover means and is there recondensed to a fluid whereby heat is transferred from said solid state electronic device by the latent heat of vaporization of said fluid to ultimately be dissipated from said cover means.
Claim 2
Dependent Claim
191 words
A package for a heat generating solid state electronic device having an active surface wherein heat is generated during operation of said device, comprising: a. base means to mechanically support said device at regions removed from said active surface; b. heat dissipating cover means forming with said base means a closed container housing said device and forming a vapor space adjacent to said device; c. electrically non-conductive capillary means on the interior surfaces of said container and in direct contact with the entire active surface of said solid state electronic device, said capillary means forming a closed flow path through which liquid may flow by capillary action; and d. an electrically non-conductive, non-polar working fluid in said capillary means, said working fluid having a boiling point such that it is evaporated from said active surface of said solid state electronic device to form a vapor which flows to the interior surfaces of said heat dissipating cover means and is there recondensed to a fluid whereby heat is transferred from said solid state electronic device by the latent heat of vaporization of said fluid to ultimately be dissipated from said cover means.
Claim 3
Dependent Claim
15 words
The invention according to claim 1, wherein said solid state device is a semiconductive device.
Claim 4
Dependent Claim
14 words
The invention according to claim 2, wherein said solid state device is a transistor.
Claim 5
Dependent Claim
58 words
The invention according to claim 1, and further including a quantity of non-condensable gas within said container, said non-condensable gas causing the volume of vapor space and the interior surface area of said hEat dissipating cover means that is exposed to said vapor to change, in response to temperature change, in a manner to oppose the temperature change.
Claim 6
Dependent Claim
186 words
A package for heat generating solid state electronic device having an active surface wherein heat is generated during operation of said device, comprising: a. thermally conductive and electrically insulating base means to mechanically support said device and to conduct heat away from another surface thereof that is spaced from said active surface; b. heat dissipating cover means forming with said base means a container housing said device and forming a vapor space adjacent to said device; c. an electrically non-conductive heat pipe wick structure in contact with said active surface of said solid state device and in contact with the interior walls of said container; and d. an electrically non-conductive, non-polar working fluid in said wick structure and in direct contact with said entire active surface, whereby boiling heat transfer utilizing the latent heat of vaporization of said working fluid that is vaporized by the heat dissipated from said active surface results in cooling of said solid state device, said wick structure serving to return working fluid condensate from the dissipating walls of said container to the heat generating active surface of said solid state device.
Claim 7
Dependent Claim
186 words
A package for heat generating solid state electronic device having an active surface wherein heat is generated during operation of said device, comprising: a. thermally conductive and electrically insulating base means to mechanically support said device and to conduct heat away from another surface thereof that is spaced from said active surface; b. heat dissipating cover means forming with said base means a container housing said device and forming a vapor space adjacent to said device; c. an electrically non-conductive heat pipe wick structure in contact with said active surface of said solid state device and in contact with the interior walls of said container; and d. an electrically non-conductive, non-polar working fluid in said wick structure and in direct contact with said entire active surface, whereby boiling heat transfer utilizing the latent heat of vaporization of said working fluid that is vaporized by the heat dissipated from said active surface results in cooling of said solid state device, said wick structure serving to return working fluid condensate from the dissipating walls of said container to the heat generating active surface of said solid state device.
Claim 8
Dependent Claim
13 words
Apparatus as in claim 5 wherein said wick material consists of silica glass.
Claim 9
Dependent Claim
11 words
Apparatus as in claim 5 wherein said vaporizable substance is pentane.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |