US20060274502A1

US20060274502A1 - Electronic package whereby an electronic assembly is packaged within an enclosure that is designed to act as a heat pipe

Info

Publication number: US20060274502A1
Application number: US11/440,942
Authority: US
Inventors: Robert Rapp
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-06-01
Filing date: 2006-05-25
Publication date: 2006-12-07
Also published as: US20090073657A1; US7679911B2

Abstract

An electronic component or assembly that is assembled within a case that is designed to operate as a liquid phase to gas phase heat pipe where said electronic component or assembly is introduced into a liquid or partially liquid partially gaseous environment; whereby said liquid evaporates into a gas absorbing heat energy and transferring it to and through the component's or assembly's case. The case will be engineered out of materials that do not contaminate the liquid and electronics with ions and will be engineered to operate in any physical orientation.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

Application No. 60/686,289 Filing Date: Jun. 1, 2005 Confirmation # 7771, is a Provisional Patent application for which this application is a non-provisional Utility Patent follow up by the same inventor, Robert J. Rapp customer #41400.

FEDERAL RESEARCH STATEMENT

Not Applicable, this invention was developed without government assistance.

BACKGROUND OF THE INVENTION

Heat pipes have been used to cool electronics for some time, yet heat pipes that use heat to evaporate a liquid into a gas are not contained within the same physical case such that the liquid that performs the cooling function is in direct contact with conducive surfaces of an electronic component or electronic assembly contained within said enclosure or case. Typically heat pipes are added to electronic devices after they have been manufactured into a component or electronic sub-assembly and are not designed into the components case from the very beginning.
Evaporative heat pipes are available for purchase as separate devices that can be added to electronic assemblies to cool them, yet these devices do not encase or enclose the electronic components that they cool. These types of heat pipes typically use materials are not well suited to enclosing electronic components with exposed conductive surfaces as they use materials that give up ions easily, as they use materials such as copper and water. If these materials were used to encase and cool electronics with exposed metallic interconnects the electronics would be contaminated by ions that would short and/or corrode metallic contacts contained within. Furthermore since in these designs the liquid is not in direct contact with the electronic components themselves, a fact that limits their performance as heat must first transfer through the components case before they reach heat pipes of this sort.
Other forms of liquid cooling are not small and self contained, as they rely on circulating a liquid with a pump, or condensing a liquid by compressing a gas.
Since electronic device densities are increasing rapidly and operating at ever higher frequencies a new method for cooling electronics that can be contained within a small package would enable higher power electronics to be packaged in highly portable electronic devices that operate in configurations of high heat density. Such high heat transfer capabilities are intended to enable electronic devices to operate within current component form factors while minimizing or eliminating the need for external heat transfer mechanisms that are usually required to cool electronic components that are typically attached to conventional high heat power electronic devices.

DESCRIPTION OF THE INVENTION

Higher power devices generate vast amount of heat require rapid heat transfer capabilities to keep them functioning optimally. Evaporating liquids carry a large amount of heat energy away from a point of evaporation; this type of cooling mechanism is known as a liquid phase to gas vapor phase heat pipe. The invention describe within is a case or enclosure that surrounds an electronic component, sub-assembly, or assembly that is deigned to operate as a liquid phase to gas vapor phase heat pipe; where the case of the electronic assembly itself is designed to perform the function said liquid phase to gas vapor phase heat pipe. Here electronic components are in direct contact with a liquid, heat from the electronic components evaporates the liquid forming a gas vapor, and the vapor raises carrying heat energy to the case where this heat energy is conducted into the surrounding environment. Once the gas vapor dissipates thermal energy into the case, it condenses back into a liquid where it rains down or is wicked back down onto the electronic components. The case itself may contain a plurality of chambers where the gas vapors can rise into. A plurality of chambers would operate like a group of cooling towers, increasing the surface area in configurations where heat can be transferred more efficiently: from the gas vapor through the chamber walls and into the external environment.
Furthermore the liquid and the case would be made of materials that will not contaminate the encased electronic assembly with ions. This is an important non-obvious benefit of the design. Furthermore the case is designed to operate as a heat pipe that encloses the electronic component or assembly is small, self contained, and is designed to perform its function in any orientation. If the electronic component, sub-assembly, or assembly is inverted or turned in any physical orientation the electronics contained within will remain in contact with the liquid such that the electronic circuits are optimally cooled. The case is designed such that the gas vapor can carry the maximum amount of thermal energy to the external environment through the case given any physical orientation of the case. Furthermore the overall package may be designed such that an electronic component packaged within will fit within the same form factor as a similar component designed with conventional means, yet provide superior cooling to electronic component packaged within.
Another non-obvious benefit of this design is that such an electronic component, sub-assembly, or assembly could be soldered in place onto a circuit board in an oven, even if the electronic components inside were originally soldered with similar materials & temperatures. In this case the electronic assembly contained within the heat pipe would be protected from the external heat of the oven. The solder holding electronic components in place on the inside of the heat pipe would be cooled by the fluid contained within the heat pipe long enough for the component to be soldered to an external circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an electronic assembly whereby a case/enclosure 1A contains a conventional electronic assembly/sub-assembly 3A, a liquid 2A, and a gas vapor that forms a liquid phase to gas phase heat pipe. Also shown are pads 5A by which the overall electronic assembly may be soldered to a printed circuit board by standard assembly processes.
FIG. 2 shows an electronic assembly whereby a case/enclosure 1B contains a conventional electronic assembly/sub-assembly 3B, a liquid 2B, and a gas vapor that forms a liquid phase to gas phase heat pipe. Also shown are pads 5B by which the overall electronic assembly may be soldered to a printed circuit board by standard assembly processes. Furthermore contains a plurality of chambers/towers 6 that are designed to optimize the cooling of the electronic assembly contained within in any physical orientation.
FIG. 3 shows an electronic assembly whereby a case/enclosure 1B contains a conventional electronic assembly/sub-assembly 3C, a liquid 2C, and a gas vapor that forms a liquid phase to gas phase heat pipe. Also shown are pins 5C by which the overall electronic assembly may be soldered to a printed circuit board by standard assembly processes. Furthermore contains a plurality of chambers/towers 7 that are designed to optimize the cooling of the electronic assembly contained within in any physical orientation.

Claims

1. An enclosure that contains an electronic assembly and a liquid that is designed to operate as a heat pipe for cooling electronics contained within.

2. Claim 1 where said enclosure contains some portion of liquid and some portion of gas such that said enclosure operates as a liquid phase to a vapor phase heat pipe where said liquid evaporates into a gas vapor into a gas vapor transfers heat and condenses back into a liquid.

3. Claim 2 where said enclosure maintains some potion of said liquid in contact with said electronic assembly despite the physical orientation of said electronic assembly.

4. Claim 3 where said enclosure includes a plurality of chambers where said gas vapor can move, where said chambers are designed to maximize the surface area of said enclosure such that thermal energy is moved from said gas vapor through said enclosure more efficiently.

5. Claim 4 where said chambers are comprised of cylinders that form cooling towers and said enclosure is comprise of a material that does not freely emit ions.

6. Claim 3 where said electronic assembly consists of at least one integrated circuit.

7. Claim 6 where said integrated circuits are wire bonded.

8. Claim 6 where said integrated circuits are soldered.

9. Claim 6 where said integrated circuits are attached by conductive epoxy.

10. Claim 6 where said integrated circuits are attached by other means.

11. Claim 6 where said integrated circuits form an electronic sub-assembly.

12. Claim 3 where said electronic assembly and case are contained within the form factor of an electronic device that is packaged by means that do not use said liquid phase to gas vapor phase heat pipe.

13. Claim 4 where said electronic assembly and case are contained within the form factor of an electronic device that is packaged by means that do not use said liquid phase to gas vapor phase heat pipe.

14. Claim 5 where said electronic assembly and case are contained within the form factor of an electronic device that is packaged by means that do not use said liquid phase to gas vapor phase heat pipe.