Ceramic heat pipe with porous ceramic wick

Abstract

A heat pipe for transporting heat from light emitting elements includes a sealed body made of a non-porous ceramic, a vapor channel inside the body that extends between two heat transfer locations spaced apart on an exterior surface of the body, a ceramic wick inside the body that extends between the two heat transfer locations, and a working fluid that partially fills the vapor transport channel. In a method of making this heat pipe, the body and wick are desirably formed together as a seamless monolithic structure made of the same ceramic material. Using a ceramic makes the heat pipe corrosion resistant and allows electrical components like LEDs to be mounted directly on the body because the ceramic is a dielectric.

Description

BACKGROUND OF THE INVENTION[0001]The present invention is directed to a heat pipe that transports heat away from heat producing bodies, such as light emitting diodes (LEDs).[0002]LEDs generate heat as well as light and the heat is desirably transported away from the LEDs because elevated LED-junction operating temperatures (e.g., above about 115° C.) adversely affect light output. Heat can be transported away from the LEDs by mounting the LEDs on a substrate (heat sink) of sufficient thermal conductivity and appropriate surface area from which to dissipate the heat. However, conventional metal and ceramic substrates often do not have sufficient thermal conductivity, especially when many LEDs are placed in a small area. Consequently, a supporting substrate with improved thermal conductivity suitable for use with LEDs is desired.[0003]A heat pipe is a heat transfer device that can transport large quantities of heat, significantly more than conventional metal and ceramic heat sinks, fr...

AI Technical Summary

Benefits of technology

[0006]An object of the present invention is to provide a novel heat pipe made entirely of ceramic that resists corrosion and on which electrical components such as LEDs can be mounted directly.

[0010]Yet another object of the present invention is to provide a novel method of making this heat pipe where the body and wick are provided from the same ceramic material and are formed together as a seamless monolithic structure made of the same ceramic material.

Problems solved by technology

LEDs generate heat as well as light and the heat is desirably transported away from the LEDs because elevated LED-junction operating temperatures (e.g., above about 115° C.) adversely affect light output.

However, conventional metal and ceramic substrates often do not have sufficient thermal conductivity, especially when many LEDs are placed in a small area.

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