Heat pipes, commonly used for heat dissipation and thermal management in small electronic and communication devices, are regarded as an excellent solution. Heat pipes must be in surface rather than line contact to be applied to the module and system-level heat dissipation package. As such, a round copper heat pipe is transformed into a plate-like shape through a secondary press process. In this study, an extrusion structure is designed to be sloped to solve the difficulty of making it relatively thin compared with the large area of the plate structure. Specifically, substantial partitions separating the working fluid flow space in the plate-type heat pipe are designed to be inclined at 45 deg, and the extruded envelope is developed to obtain the desired total thickness through the secondary press process. The capillary structure is inserted and positioned within the envelope prior to the secondary press process. In this study, an aluminum flat heat pipe (AFHP) with 0.95 mm total thickness, 150 mm total length, and a capillary structure with braided or carbon wire bundles added thereto was designed and manufactured. Performance test results indicated that the heat transfer performance of the AFHP with inclined wall did not show any deterioration characteristic compared with the AFHP with a normal vertical wall. The isothermal characteristics and heat transfer rate of the AFHP with Cu braid wick were superior to those of AFHP with a simple rectangular groove wick. By contrast, when the carbon wire bundle is added in the Cu braid, the isothermal characteristic was enhanced twice, and the heat transfer rate was 15.5 W by improving approximately 42% under the conditions that inclination angle is −90 deg and the evaporator temperature does not exceed 110 °C.

References

1.
Ahamed
,
M. S.
,
Saito
,
Y.
,
Mochizuki
,
M.
, and
Mashiko
,
K.
,
2015
, “
Hot Spot Elimination by Thin and Smart Heat Spreader
,”
ASME
Paper No. IPACK2015-48019.
2.
Moon
,
S. H.
,
Park
,
Y. W.
, and
Rhi
,
S. H.
,
2017
, “
The Carbon Wire Bundle's Constructing as a Capillary Wick in the Flat Thin Heat Pipe
,”
Appl. Therm. Eng.
,
126
, pp.
1177
1184
.
3.
Ghajar
,
M.
, and
Darabi
,
J.
,
2014
, “
Evaporative Heat Transfer Analysis of a Micro Loop Heat Pipe With Rectangular Grooves
,”
Int. J. Therm. Sci.
,
79
, pp.
51
59
.
4.
Wang
,
C.
,
Liu
,
Z.
,
Zhang
,
G.
, and
Zhang
,
M.
,
2013
, “
Experimental Investigations of Flat Plate Heat Pipes With Interlaced Narrow Grooves or Channels as Capillary Structure
,”
Exp. Therm. Fluid Sci.
,
48
, pp.
222
229
.
5.
Yang
,
Y. X.
,
Wang
,
X. D.
,
Luo
,
Y.
, and
Zou
,
L. L.
,
2014
, “
Heat Transfer Characteristic of Flat Trapezoid Grooved Micro Heat Pipes
,”
Key Eng. Mater.
,
609–610
, pp.
1526
1531
.
6.
Lefvre
,
F.
,
Conrardy
,
J.-B.
,
Raynaud
,
M.
, and
Bonjour
,
J.
,
2012
, “
Experimental Investigations of Flat Plate Heat Pipes With Screen Meshes or Grooves Covered With Screen Meshes as Capillary Structure
,”
Appl. Therm. Eng.
,
37
, pp.
95
102
.
7.
Ponnappan
,
R.
,
2002
, “
Novel Groove-Shaped Screen-Wick Miniature Heat Pipe
,”
J. Thermophys. Heat Transfer
,
16
(
1
), pp.
17
21
.
8.
Xibing
,
L.
,
Mingjian
,
L.
,
Ming
,
L.
,
Ruchen
,
W.
,
Yingsi
,
W.
, and
Cheng
,
T.
,
2015
, “
Forming Method of Micro Heat Pipe With Compound Structure of Sintered Wick on Grooved Substrate
,”
Heat Mass Transfer
,
52
(
3
), pp.
1
13
.
9.
Hsieh
,
J. C.
,
Huang
,
H. J.
, and
Shen
,
S. C.
,
2012
, “
Experimental Study of Microrectangular Groove Structure Covered With Multi Mesh Layers on Performance of Flat Plate Heat Pipe for LED Lighting Module
,”
Microelectron. Reliab.
,
52
(
6
), pp.
1071
1079
.
10.
Maalej
,
S.
, and
Zaghdoudi
,
M. C.
,
2007
, “
Experimental and Theoretical Analysis on Enhanced Flat Miniature Heat Pipes With Axial Capillary Grooves and Screen Meshes
,”
Thermal Issues Emerging Technology
, Cairo, Egypt, Jan. 3–6, pp. 21–32.
11.
Vadakkan
,
U.
,
Chrysler
,
G. M.
,
Maveety
,
J. B.
, and
Tirumala
,
M. A.
,
2007
, “
A Novel Carbon Nano Tube Based Wick Structure for Heat Pipes/Vapor Chambers
,”
Annual
IEEE
Semiconductor Thermal Measurement and Management Symposium, San Jose, CA
,
Mar. 18–22
, pp.
102
104
.
12.
Wang
,
Y.
, and
Gundevia
,
M.
,
2013
, “
Measurement of Thermal Conductivity and Heat Pipe Effect in Hydrophilic and Hydrophobic Carbon Papers
,”
Int. J. Heat Mass Transfer
,
60
, pp.
134
142
.
13.
Weibel
,
J. A.
,
Kim
,
S. W.
,
Fisher
,
T. S.
, and
Garimella
,
S. V.
,
2013
, “
Experimental Characterization of Capillary Fed Carbon Nanotube Vapor Chamber Wicks
,”
ASME J. Heat Transfer
,
135
(
2
), p.
021501
.
14.
Holman
,
J. P.
,
2001
,
Experimental Methods for Engineers
,
McGraw-Hill
,
New York
.
You do not currently have access to this content.