Thermal-Structural Performance of Orthotropic Pin Fin Applications

2009 ◽  
Author(s):  
Abul Fazal M. Arif ◽  
Syed M. Zubair
Keyword(s):  
Structural Response ◽  
Base Plate ◽  
Heat Sinks ◽  
Thermal Interface ◽  
Conductive Composites ◽  
Pin Fin ◽  
Thermally Conductive ◽  
As Stress ◽  
Reduced Density ◽  
Interface Materials

Thermally conductive composites as compared to metals have reduced density, decreased corrosion, oxidation, and chemical resistance, as well as adjustable properties to fit a given application. However, there are several challenges that need to be addressed before they can be successfully utilized in heat sink design. The interface between the device and thermal product that is used to cool it is an important factor in the thermal network designs of microelectronics cooling. Depending on the thermal interface conditions and material properties, the contact pressure and thermal stress level can attain undesirable values. In this paper, we investigate the effect of thermal interface between the fin and base plate on thermalstructural behavior of heat sinks. A coupled-field (thermal-structural) analysis using finite element method is performed to predict temperature as well as stress fields in the region of interface. In addition temperature and heat transfer rate predictions is supported through analytical results. Effect of various interface properties (such as air gap with rough surface and gaps filled with interface material) on the resulting thermal-structural response of the pin fin is investigated with respect to four interface materials combinations.

Thermal-Structural Performance of Orthotropic Pin Fin in Electronics Cooling Applications

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
A. F. M. Arif ◽  
Syed M. Zubair ◽  
S. Pashah
Keyword(s):  
Heat Sink ◽  
Structural Response ◽  
Electronics Cooling ◽  
Base Plate ◽  
Thermal Design ◽  
Heat Flow Rate ◽  
Thermal Interface ◽  
Conductive Composites ◽  
Thermally Conductive ◽  
As Stress

Thermally conductive composites as compared to metals have reduced density, decreased oxidation, and improved chemical resistance, as well as adjustable properties to fit a given application. However, there are several challenges that need to be addressed before they can be successfully implemented in heat sink design. The interface between the device and heat sink is an important factor in the thermal design of microelectronics cooling. Depending on the thermal interface conditions and material properties, the contact pressure and thermal stress level can attain undesirable values. In this paper, we investigate the effect of thermal interface between the fin and base plate on thermal-structural behavior of heat sinks. A coupled-field (thermal-structural) analysis using finite element method is performed to predict temperature as well as stress fields in the interface region. In addition temperature and heat flow rate predictions are supported through analytical results. effect of various interface geometrical (such as slot-depth, axial-gap, and radial-gap) and contact properties (such as air gap with surface roughness and gaps filled with interface material) on the resulting thermal-structural response is investigated with respect to four interface materials combinations, and it is found that the thermal performance is most sensitive to the slot-depth compared to any other parameter.

scholarly journals Ball-Milled Recycled Lead-Graphite Pencils as Highly Stretchable and Low-Cost Thermal-Interface Materials

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 799 ◽  
Author(s):  
Chun-An Liao ◽  
Yee-Kwan Kwan ◽  
Tien-Chan Chang ◽  
Yiin-Kuen Fuh
Keyword(s):  
Low Cost ◽  
Exfoliated Graphite ◽  
Thermal Interface Materials ◽  
Graphite Nanoplatelets ◽  
Thermal Interface ◽  
Thermally Conductive ◽  
Highly Stretchable ◽  
Exfoliated Graphite Nanoplatelets ◽  
Interface Materials ◽  
Thermal Conductivities

A simple and sustainable production of nanoplatelet graphite at low cost is presented using carbon-based materials, including the recycled lead-graphite pencils. In this work, exfoliated graphite nanoplatelets (EGNs), ball-milled exfoliated graphite nanoplatelets (BMEGNs) and recycled lead-graphite pencils (recycled 2B), as well as thermally cured polydimethylsiloxane (PDMS), are used to fabricate highly stretchable thermal-interface materials (TIMs) with good thermally conductive and mechanically robust properties. Several characterization techniques including scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) showed that recycled nanoplatelet graphite with lateral size of tens of micrometers can be reliably produced. Experimentally, the thermal conductivity was measured for EGNs, BMEGNs and recycled 2B fillers with/without the effect of ball milling. The in-plane thermal conductivities of 12.97 W/mK (EGN), 13.53 W/mK (recycled 2B) and 14.56 W/mK (BMEGN) and through-plane thermal conductivities of 0.76 W/mK (EGN), 0.84 W/mK (recycled 2B) and 0.95 W/mK (BMEGN) were experimentally measured. Anisotropies were calculated as 15.31, 15.98 and 16.95 for EGN, recycled 2B and BMEGN, respectively. In addition, the mechanical robustness of the developed TIMs is such that they are capable of repeatedly bending at 180 degrees with outstanding flexibility, including the low-cost renewable material of recycled lead-graphite pencils. For heat dissipating application in high-power electronics, the TIMs of recycled 2B are capable of effectively reducing temperatures to approximately 6.2 °C as favorably compared with thermal grease alone.

The Progress of Graphene in Thermal Transportation

2014 ◽  
Vol 1039 ◽  
pp. 438-445 ◽  
Author(s):  
Ming Zhu Wang ◽  
Xing Xing ◽  
Wei Yu
Keyword(s):  
Thermal Management ◽  
Test Methods ◽  
Research Progress ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Conductive Composites ◽  
Nanocarbon Material ◽  
Conductive Property ◽  
Interface Materials ◽  
Application Prospects

Graphene, a two-dimensional nanocarbon material with unique planar structure, has wide application prospects in the field of thermal management due to its excellent thermal conductive property. The test methods for thermal conductivity of graphene are described. Research progress in the application of graphene in the field of thermal management is reviewed. Especially, the application of graphene in nanofluids, thermal interface materials and thermal conductive composites is described in detail.

Thermo-Mechanical Fatigue Life Prediction of Orthotropic Composite Pin Fin Heat Sinks for Electronic Packaging

2011 ◽  
Author(s):  
Sulaman Pashah ◽  
Abul Fazal M. Arif
Keyword(s):  
Thermal Performance ◽  
Heat Sink ◽  
Electronic Packaging ◽  
Base Plate ◽  
Heat Sinks ◽  
Metallic Base ◽  
Plate Interface ◽  
Pin Fin ◽  
Pin Fins ◽  
Reliability Performance

Heat sinks are used in modern electronic packaging system to enhance and sustain system thermal performance by dissipating heat away from IC components. Pin fins are commonly used in heat sink applications. Conventional metallic pins fins are efficient in low Biot number range whereas high thermal performance can be achieved in high Biot number regions with orthotropic composite pin fins due to their adjustable thermal properties. However, several challenges related to performance as well as manufacturing need to be addressed before they can be successfully implemented in a heat sink design. A heat sink assembly with metallic base plate and polymer composite pin fins is a solution to address manufacturing constraints. During the service life of an electronic packaging, the heat sink assembly is subjected to power cycles. Cyclic thermal stresses will be important at the pin-fin and base-plate interface due to thermal mismatch. The cyclic nature of stresses can lead to fatigue failure that will affect the reliability of the heat sink and electronic packaging. A finite element model of the heat sink is used to investigate the thermal stress cyclic effect on thermo-mechanical reliability performance. The aim is to assess the reliability performance of the epoxy bond at the polymer composite pin fins and metallic base plate interface in a heat-sink assembly.

scholarly journals Globular Flower-Like Reduced Graphene Oxide Design for Enhancing Thermally Conductive Properties of Silicone-Based Spherical Alumina Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 544
Author(s):  
Weijie Liang ◽  
Tiehu Li ◽  
Xiaocong Zhou ◽  
Xin Ge ◽  
Xunjun Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Reduced Graphene ◽  
The Matrix ◽  
Thermally Conductive ◽  
Interface Materials ◽  
Spherical Alumina

The enhancement of thermally conductive performances for lightweight thermal interface materials is a long-term effort. The superb micro-structures of the thermal conductivity enhancer have an important impact on increasing thermal conductivity and decreasing thermal resistance. Here, globular flower-like reduced graphene oxide (GFRGO) is designed by the self-assembly of reduced graphene oxide (RGO) sheets, under the assistance of a binder via the spray-assisted method for silicone-based spherical alumina (S-Al2O3) composites. When the total filler content is fixed at 84 wt%, silicone-based S-Al2O3 composites with 1 wt% of GFRGO exhibit a much more significant increase in thermal conductivity, reduction in thermal resistance and reinforcement in thermal management capability than that of without graphene. Meanwhile, GFRGO is obviously superior to that of their RGO counterparts. Compared with RGO sheets, GFRGO spheres which are well-distributed between the S-Al2O3 fillers and well-dispersed in the matrix can build three-dimensional and isotropic thermally conductive networks more effectively with S-Al2O3 in the matrix, and this minimizes the thermal boundary resistance among components, owning to its structural characteristics. As with RGO, the introduction of GFRGO is helpful when decreasing the density of silicone-based S-Al2O3 composites. These attractive results suggest that the strategy opens new opportunities for fabricating practical, high-performance and light-weight filler-type thermal interface materials.

Metal-Level Thermally Conductive yet Soft Graphene Thermal Interface Materials

ACS Nano ◽  
2019 ◽  
Vol 13 (10) ◽  
pp. 11561-11571 ◽  
Author(s):  
Wen Dai ◽  
Tengfei Ma ◽  
Qingwei Yan ◽  
Jingyao Gao ◽  
Xue Tan ◽  
...  
Keyword(s):  
Metal Level ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Thermally Conductive ◽  
Interface Materials

Thermal and Structural Response of Pin Fins for Different Interface Conditions

2010 ◽  
Author(s):  
Abul Fazal M. Arif ◽  
Sulaman Pashah ◽  
Syed M. Zubair ◽  
M. Inam
Keyword(s):  
Thermal Performance ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Structural Response ◽  
Operating Conditions ◽  
Stress Fields ◽  
Power Device ◽  
Interface Conditions ◽  
Thermal Interface ◽  
Pin Fin

Thermal management of electronic products relies on the effective dissipation of heat. Heat sink elements (e.g. a pin fin) are used for any effective heat dissipation network. Despite much optimized design of the heat sink element, the heat transfer may not be effective because the interface between power device and heat sink element is critical in the heat dissipation network. Thermal Interface Materials TIM (e.g. adhesive, solder, pads, or pastes) are employed at interface between power device and heat sink element to minimize the interface thermal resistance. However, several challenges need to be addressed before they can be successfully utilized because depending on the thermal interface conditions, the thermal stress level can attain undesirable values. This issue can be addressed by the optimization of the system design with the help of simulation methods. Generally the effects of interface conditions are studied on the thermal performance of the heat sink system whereas in this paper, a coupled-field (thermal-structural) analysis using FEM is performed to study the thermal as well as structural behavior of the heat sink system. Temperature variation and stress fields in the region of interface between pin fin and base plate are analyzed. Effects of various parameters (such as contact pressure, surface roughness, TIM thickness, and operating conditions) on the resulting thermal and structural response at the interface are presented. It has been found that different interface conditions may have comparable thermal performance with significant different stress fields at the interface. Therefore stress state must be known to ensure the structural integrity of the heat sink system for a given operating condition.

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