Flat heat pipe

Patent metadata

Field	Value
Publication number	US-2016018166-A1
Application number	US-201514799719-A
Country	US
Kind code	A1
Filing date	Jul 15, 2015
Priority date	Jul 16, 2014
Publication date	Jan 21, 2016
Grant date	—

Abstract

A heat pipe a flat heat pipe having enhanced heat transport capacity is provided. The flat heat pipe 1 comprises a working fluid encapsulated in a container 2, a first wick 11 that returns the working fluid from a condensing portion 4 to an evaporating portion 3 by a capillary pumping, and a second wick 12 that spreads the working fluid returned thereto over an inner face of the container by a capillary pumping. The second wick is formed only in the evaporating portion 3 to extend in a circumferential direction on the inner face of the container 2.

First claim

What is claimed is:

1 . A flat heat pipe, comprising:
a sealed container having a pair of upper and lower flat walls extending in a length direction; a working fluid encapsulated in the container; an evaporating portion that is situated on one of the longitudinal ends of the container at which evaporation of the working fluid takes place; a condensing portion that is situated on the other longitudinal end of the container at which condensation of the working fluid takes place; a first wick formed of a bundled fibers or a porous structure that extends in the length direction of the container to return the working fluid condensed at the condensing portion to the evaporating portion by a capillary pumping; and a second wick that is formed by forming a groove on an inner face of the container only in the evaporating portion to spread the working fluid returned thereto over the inner face within the evaporating portion by a capillary pumping; wherein the first wick is formed on at least one of the upper flat wall or the lower flat wall; and wherein the second wick transversely extends underneath the first wick to be closed partially by the first wick.

2 . The flat heat pipe as claimed in claim 1 , wherein the second wick is formed on the inner face of the container in the evaporating portion in a spiral manner.

3 . The flat heat pipe as claimed in claim 1 , wherein the second wick is formed on the inner face of the container in the evaporating portion in a circular manner.

4 . The flat heat pipe as claimed in claim 1 , wherein the second wick is formed only on the inner face of one of the upper flat face and the lower flat face on which the first wick is formed.

5 . The flat heat pipe as claimed in claim 1 , wherein the second wick includes an opening portions extending from both sides of the first wick in the circumferential direction.

6 . The flat heat pipe as claimed in claim 1 , wherein the porous structure is formed by sintering metal powders.

7 . The flat heat pipe as claimed in claim 1 , wherein the first wick is formed of copper fibers.

8 . The flat heat pipe as claimed in claim 1 , wherein the first wick is formed of carbon fibers.

9 . The flat heat pipe as claimed in claim 1 , wherein the first wick is formed of a mixture of carbon fibers and copper fibers.

Assignees

• Fujikura Ltd

Inventors

• Ahamed Mohammad Shahed
• Saito Yuji

Classifications

• F28D15/0233 Primary

  the conduits having a particular shape, e.g. non-circular cross-section, annular (F28D15/0241, F28D15/0266 take precedence) · CPC title

• F28D15/04 Primary

  with tubes having a capillary structure · CPC title

• F28D15/046

  characterised by the material or the construction of the capillary structure · CPC title