The purpose of this invention is to provide a sheet-shaped heat pipe that makes it possible to reduce a pressure loss caused by a vapor flow or a pressure loss caused by a working fluid flow to improve the maximum amount of heat to be transported and reduce thermal resistance by increasing the cross-sectional area of a vapor flow passage or a fluid flow passage, which has been limited by the length of a container in a height direction. A heat pipe ( 20 ) is provided with a protruding portion ( 24 ) so that the height of the wick-occupied portion ( 23 ) serving as the fluid flow passage is larger than the height of the space portion ( 22 ) serving as the vapor flow passage.
1. A sheet-shaped heat pipe comprising:
a container in which a hollow portion is formed;
a wick structure that is stored in the container and generates a capillary force; and
working fluid that is sealed in the hollow portion formed in the container,
wherein the hollow portion formed in the container includes a wick-occupied portion that is entirely occupied by the wick structure, and a space portion that is not occupied by the wick structure,
a protruding portion formed in the container as part of the wick-occupied portion and having a shape in which a widthwise cross-section of the protruding portion protrudes in a height direction of the wick-occupied portion, and a longitudinal direction of the protruding portion extends along the surface of the container, and
the protruding portion is provided so that the height of the wick-occupied portion is larger than the height of the space portion, wherein the height, T, of the protruding portion satisfies
T
>
ω
=
0.14
x
(
P
0
-
P
)
a
4
E
h
3
,
where 0.05×10 −3 ≤h≤3×10 −3 , and
T in meters is the height of the protruding portion, ω in meters is a maximum amount of deformation of a top side of the space portion, and a in meters is a distance between the wick-occupied portion and a next wick-occupied portion, P 0 in pascals is the atmospheric pressure, P in pascals is the internal pressure of each of the heat pipe, E in pascals is the modulus of longitudinal elasticity of the container, and h in meters is the thickness of the container,
the space portion being interposed between the wick-occupied portion and the next wick-occupied portion.
2. The heat pipe according to claim 1 ,
wherein the protruding portion is formed on each of both surfaces of the container that are disposed so as to face each other in a height direction.
3. The heat pipe according to claim 1 ,
wherein the height of a widthwise middle portion of the protruding portion is larger than the height of a bottom, from which the protruding portion starts to be raised, in the widthwise cross-section of the protruding portion.
4. The heat pipe according to claim 1 or 2 ,
wherein the height of the protruding portion is increased or decreased in the longitudinal direction of the protruding portion.
5. The heat pipe according to claim 1 or 2 ,
wherein parallel protruding portions, which are a plurality of the protruding portions of which longitudinal directions are aligned in one direction and which are disposed in parallel, are formed integrally with a communication-protruding portion that is the protruding portion allowing the plurality of parallel protruding portions to communicate with one another.
6. A heat sink comprising:
the heat pipe according to claim 1 or 2 and
a heat radiation fin.
7. A heat sink comprising:
the heat pipe according to claim 3 and
a heat radiation fin.
8. A heat sink comprising:
the heat pipe according to claim 4 and
a heat radiation fin.
9. A heat sink comprising:
the heat pipe according to claim 5 and
a heat radiation fin.