The aim of the present work is to study the thermal performance of a hybrid heat sink used for cooling management of protruding substrate-mounted electronic chips. The power generated in electronic chips is dissipated in phase change material (PCM) (n-eicosane with melting temperature $Tm=36°C$) that filled a rectangular enclosure. The advantage of using this cooling strategy is that the PCMs are able to absorb a high amount of heat generated by electronic component (EC) without acting the fan, during the charging process (melting of the PCM). A two-dimensional mathematical model was developed in order to analyze and optimize a heat sink. The governing equations for masse, momentum, and energy transport were developed and discretized by using the volume control approach. The resulting algebraic equations were next solved iteratively by using tri diagonal matrix algorithm. A series of numerical investigations were conducted in order to examine the effects of the heat generation based Rayleigh number, Ra, and the position of the bottom electronic component, $Lh$, on the thermal behavior of the proposed cooling system. Results are obtained for velocity and temperature distributions, maximum temperature heat sources, percentage contribution of plate (substrate) heat conduction on the heat removal from electronic components, temperature profile within finite conductive plate and local heat flux density at the plate—modules/PCM interface. The effect of these two key parameters on the electronic component working time (time required by electronic components to reach a critical temperature, $Tcr$) was analyzed.

1.
Joiner
,
B.
, and
Neelakantan
,
S.
, 2006, “Integrated Circuit Package Types and Thermal Characteristics,” Electron. Cool., 12(1), pp. 10–17.
2.
Lin
,
S. C.
, and
Huang
,
C. L.
, 2001, “
The Study of a Small Centrifugal Fan for Notebook Computer
,”
J. Chin. Soc. Mech. Eng.
0257-9731,
22
(
5
), pp.
421
431
.
3.
Dreyer
M.
, 2006, “New Thermal Cooling Addresses the Shrinking Electronics,” Equipment Protection Magazine, 4(1), pp. 1–24.
4.
Nakayama
,
W.
, 1987, “
Survey of Design Approaches in Japanese Computer
,”
International Symposium on Cooling Technology
, Honolulu, HI.
5.
Krishnan
,
Sh.
, and
Garimella
,
S. V.
, 2004, “
Analysis of a Phase Change Energy Storage System for Pulsed Power Dissipation
,”
IEEE Trans. Compon. Packag. Technol.
1521-3331,
27
(
1
), pp.
191
199
.
6.
Kandasamy
,
R.
,
Wang
,
X. Q.
, and
Mujumdar
,
A. S.
, 2007, “
Application of Phase Change Materials in Thermal Management of Electronics
,”
Appl. Therm. Eng.
1359-4311,
27
, pp.
2822
2832
.
7.
Zhang
,
Y.
,
Chen
,
Z.
,
Wang
,
Q.
, and
Wu
,
Q.
, 1993, “
Melting in an Enclosure With Discrete Heating at a Constant Rate
,”
Exp. Therm. Fluid Sci.
,
6
, pp.
196
201
. 0894-1777
8.
Hodes
,
M.
,
Weinstein
,
R. D.
,
Pence
,
S. J.
,
Piccini
,
J. M.
,
Manzione
,
L.
, and
Chen
,
C.
, 2002, “
Transient Thermal Management of a Handset Using Phase Change Material (PCM)
,”
ASME J. Electron. Packag.
1043-7398,
124
, pp.
419
426
.
9.
Tan
,
F. L.
, and
Tso
,
C. P.
, 2004, “
Cooling of Mobile Electronic Devices Using Phase Change Materials
,”
Appl. Therm. Eng.
1359-4311,
24
, pp.
159
169
.
10.
Shanmugasundaram
,
V.
,
Brown
,
J. R.
, and
Yerkes
,
K. L.
, 1997, “
Thermal Management of High Heat Flux Sources Using Phase Change Material, a Design Optimization
,” AIAA Paper No. AIAA-97-2451.
11.
Voller
,
V. R.
, 1997, “
An Overview of Numerical Methods for Solving Phase Change Problems
,”
, Vol.
1
,
W. J.
Minkowycz
and
E. M.
Sparrow
, eds.,
Taylor and Francis
,
Basingstoke
.
12.
Patankar
,
S. V.
, 1980,
Numerical Heat Transfer and Fluid Flow
,
Hemisphere
,
Washington, DC
.
13.
Gau
,
C.
, and
Viskanta
,
R.
, 1984, “
Melting and Solidification of a Metal System in a Rectangular Cavity
,”
Int. J. Heat Mass Transfer
0017-9310,
27
(
1
), pp.
113
123
.
14.
Guenin
,
B. M.
, 2001, “Component Thermal Characterization,” Electronics Cooling, 7(1), pp. 36–44.
15.
Dorre
,
E.
, and
Hubner
,
H.
, 1984,
Alumina—Processing, Properties and Applications
,
Springer-Verlag
,
Berlin
, pp.
1
267
.
16.
Tummala
,
R. R.
, 2001,
Fundamentals of Micro Systems Packaging
,
McGraw-Hill
,
New York
.
17.
Binet
,
B.
, and
Lacroix
,
M.
, 2000, “
Melting From Heat Sources Flush Mounted on a Conducting Vertical Wall
,”
Int. J. Numer. Methods Heat Fluid Flow
0961-5539,
10
(
3
), pp.
286
307
.