Low cost, high thermal conductivity composite heat spreaders for power electronics

2002 ◽  
Author(s):  
W. Kowbel ◽  
W. Champion ◽  
J.C. Withers ◽  
W. Shih
Keyword(s):  
Thermal Conductivity ◽  
Power Electronics ◽  
Low Cost ◽  
High Thermal Conductivity ◽  
Heat Spreaders ◽  
Composite Heat

A Novel, Low-Cost C-C Composite Heat Sink Material

1996 ◽  
Vol 445 ◽  
Author(s):  
W. Kowbel ◽  
V. Chellappa ◽  
J.C. Withers
Keyword(s):  
Thermal Conductivity ◽  
Heat Sink ◽  
Low Cost ◽  
Mechanical And Thermal Properties ◽  
New Class ◽  
Dielectric Coatings ◽  
Potential Applications ◽  
New Material ◽  
New Type ◽  
Composite Heat

AbstractRapid advances in high power electronics packaging require the development of new heat sink materials. Advanced composites designed to provide thermal expansion control as well as improved thermal conductivity have the potential to provide benefits in the removal of excess heat from electronic devices. Carbon-carbon (C-C) composits are under consideration for several military and space electronic applications including SEM-E electronic boxes. The high cost of C-C composits has greatly hindered their wide spread commercialization. A new manufacturing process has been developed to produce high thermal conductivity (over 400 W/mK) C-C composites at greatly reduced cost (less than $50/lb). This new material has potential applications as both a heat sink and a substrate. Dielectric coatings such as A1N and diamond were applied to this new type of heat sink material. Processing, as well as mechanical and thermal properties of this new class of heat sink material will be presented.

scholarly journals Thermal Conductivity and the Cooling Performance of Cu Alloy-Graphite Composite Heat Spreaders Fabricated by the Powder Metallurgy.

2001 ◽  
Vol 109 (1275) ◽  
pp. 944-949 ◽  
Author(s):  
Chihiro KAWAI ◽  
Yoshiyuki HIROSE ◽  
Hirohiko NAKATA ◽  
Nobuyoshi TATOH ◽  
Tadashi TOMIKAWA
Keyword(s):  
Thermal Conductivity ◽  
Powder Metallurgy ◽  
Graphite Composite ◽  
Cooling Performance ◽  
Cu Alloy ◽  
Heat Spreaders ◽  
Composite Heat

Advanced DBC - Highly Reliable and Conductive Copper Ceramic Substrates

2016 ◽  
Vol 2016 (CICMT) ◽  
pp. 000073-000078
Author(s):  
Paul Gundel ◽  
Anton Miric ◽  
Kai Herbst ◽  
Melanie Bawohl ◽  
Jessica Reitz ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Cycling ◽  
Power Electronics ◽  
Thick Film ◽  
Low Cost ◽  
Automotive Applications ◽  
Ceramic Substrates ◽  
Hybrid Technologies

Abstract So far Direct Bonded Copper (DBC) substrates have been the standard for power electronics. They provide excellent electrical and thermal conductivity at low cost. Weaknesses of DBC technology are the inevitable warpage and the relatively low reliability under thermal cycling. The low reliability poses a significant hurdle in particular for automotive applications with high lifetime requirements. Thick Print Copper (TPC) substrates with low warpage and excellent reliability overcome these weaknesses, but also provide a reduced conductivity at a higher cost. We present two thick-film/DBC hybrid technologies which combine the best properties of DBC and TPC: excellent conductivity, low cost, reduced warpage and excellent reliability.

scholarly journals Transport in Passive, High Thermal, Conductivity Heat Spreaders

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Ram Ranjan ◽  
Suresh V. Garimella ◽  
Jayathi Y. Murthy
Keyword(s):  
Thermal Conductivity ◽  
High Thermal Conductivity ◽  
Heat Spreaders

NUMERICAL STUDY ON THE THERMAL PERFORMANCE OF A PHASE CHANGE HEAT EXCHANGER (PCHE) WITH INNOVATIVE FRACTAL TREE-SHAPED FINS

Fractals ◽  
2020 ◽  
Vol 28 (05) ◽  
pp. 2050083
Author(s):  
XIANGDONG LIU ◽  
FEIFAN LIU ◽  
QIAOBO DAI ◽  
FENG YAO ◽  
TIANJUN ZENG ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Exchanger ◽  
Phase Change ◽  
Solidification Front ◽  
Numerical Study ◽  
Low Cost ◽  
Pure Copper ◽  
Evaluation Criteria ◽  
Temperature Response ◽  
High Thermal Conductivity

For alleviating energy shortage and environmental problems, it is of great importance to improve the energy charging and discharging efficiency of thermal energy storage systems. In this context, an innovative phase change heat exchanger (PCHE) with fractal tree-shaped fins is presented in this paper. A numerical investigation of the solidification behaviors in the PCHE with fractal tree-shaped fins is conducted. The dynamic temperature response and the solidification front evolution in the PCHE are analyzed and discussed. Furthermore, two evaluation criteria, including total solidification time and energy charging efficiency, are introduced to quantitatively study the effect of fin material on the solidification heat transfer characteristics. The results indicate that the fractal tree-shaped fin leads to a uniform temperature distribution of phase change material (PCM). The temperature response of fin is faster than that of PCM due to its high thermal conductivity. Moreover, the fractal tree-shaped fin breaks the restriction of gradually forward fashion of solidification front in the traditional PCHE and dramatically improves the energy discharging performance. The material of fractal tree-shaped fins is an essential factor affecting the solidification performance of the PCHE. The energy discharging performance of PCHE with pure copper fins is the best, whereas that with cupronickel fins is the worst. However, from the perspective of practical application, aluminum is the best potential alternative because of its relatively high thermal conductivity, lighter weight, and low cost.

An electron microscopy study of high-thermal-conductivity ribbon-shape carbon fibers

1993 ◽  
Vol 51 ◽  
pp. 618-619
Author(s):  
Kerry E. Robinson
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Liquid Crystalline ◽  
Structural Information ◽  
Low Cost ◽  
Microscopy Study ◽  
High Thermal Conductivity ◽  
Mesophase Pitch ◽  
Thermal Conductivities ◽  
Shaped Fibers

In an effort to develop a low-cost high thermal conductivity carbon fiber, ribbon-shaped fibers were meltspun from a liquid crystalline, mesophase pitch precursor. Initial tests indicated that the ribbon-shaped fibers could be processed more easily and exhibited improved thermal conductivities when compared to commercial round fibers. Evidently, it is the more linear, polycrystalline structure within these fibers that accounts for their improved thermal conductivities. Thus, studies using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were conducted to fully analyze the transverse and longitudinal structure of these high thermal conductivity fibers.Ribbon-shaped fibers, melt-spun from a synthetic mesophase pitch and then heat treated, were tested to determine their tensile strengths, tensile moduli and thermal conductivities. A Jeol JSM-I C848 SEM at an accelerating voltage of 20 kV was used to obtain general structural information, such as extent and texture of lamellar organization of the graphitic layers within the fibers, and the microstructure of the fibers was studied by TEM.

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