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.

S-Shaped Pin-Fins for Enhancement of Overall Performance of the Pin-Fin Heat Sink

2010 ◽  
Author(s):  
T. J. John ◽  
B. Mathew ◽  
H. Hegab
Keyword(s):  
Reynolds Number ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Sinks ◽  
Uniform Heat Flux ◽  
Pumping Power ◽  
Pin Fin ◽  
Pin Fins ◽  
Overall Performance

In this paper the authors are studying the effect of introducing S-shaped pin-fin structures in a micro pin-fin heat sink to enhance the overall thermal performance of the heat sinks. For the purpose of evaluating the overall thermal performance of the heat sink a figure of merit (FOM) term comprising both thermal resistance and pumping power is introduced in this paper. An optimization study of the overall performance based on the pitch distance of the pin-fin structures both in the axial and the transverse direction, and based on the curvature at the ends of S-shape fins is also carried out in this paper. The value of the Reynolds number of liquid flow at the entrance of the heat sink is kept constant for the optimization purpose and the study is carried out over a range of Reynolds number from 50 to 500. All the optimization processes are carried out using computational fluid dynamics software CoventorWARE™. The models generated for the study consists of two sections, the substrate (silicon) and the fluid (water at 278K). The pin fins are 150 micrometers tall and the total structure is 500 micrometer thick and a uniform heat flux of 500KW is applied to the base of the model. The non dimensional thermal resistance and nondimensional pumping power calculated from the results is used in determining the FOM term. The study proved the superiority of the S-shaped pin-fin heat sinks over the conventional pin-fin heat sinks in terms of both FOM and flow distribution. S-shaped pin-fins with pointed tips provided the best performance compared to pin-fins with straight and circular tips.

Hydoroil-Based Micro Pin Fin Heat Sink

2006 ◽  
Author(s):  
Ali Kosar ◽  
Chih-Jung Kuo ◽  
Yoav Peles
Keyword(s):  
Heat Sink ◽  
Hydraulic Performance ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Transfer Coefficients ◽  
Pin Fin ◽  
Nusselt Numbers ◽  
Friction Factors ◽  
Pin Fins ◽  
Micro Pin Fins

An experimental study on thermal-hydraulic performance of de-ionized water over a bank of shrouded NACA 66-021 hydrofoil micro pin fins with wetted perimeter of 1030-μm and chord thickness of 100 μm has been performed. Average heat transfer coefficients have been obtained over effective heat fluxes ranging from 4.0 to 308 W/cm2 and mass velocities from 134 to 6600 kg/m2s. The experimental data is reduced to the Nusselt numbers, Reynolds numbers, total thermal resistances, and friction factors in order to determine the thermal-hydraulic performance of the heat sink. It has been found that prodigious hydrodynamic improvement can be obtained with the hydrofoil-based micro pin fin heat sink compared to the circular pin fin device. Fluid flow over pin fin heat sinks comprised from hydrofoils yielded radically lower thermal resistances than circular pin fins for a similar pressure drop.

scholarly journals Thermal Performance Improvement of a Fin-Arrayed Horizontal Heat Sink Corroborating Optimal Orientation Angle

2020 ◽  
Vol 9 (4) ◽  
pp. 1067-1075
Keyword(s):  
Heat Sink ◽  
Orientation Angle ◽  
Base Plate ◽  
Vertical Axis ◽  
Solid Base ◽  
Pin Fin ◽  
Wide Range ◽  
Pin Fins ◽  
Staggered Arrangement

The present study deals with a simple but effective technique for improving the forced convective cooling of a horizontal heat sink with vertical pin-fin-array.The pin fins are embedded in a staggered arrangement on thebase-plate of the horizontal sink. Air, while passing through the fin-array, convects the heat conducted from the solid base-plate to the fins’ surface. The objective of this paper is to examine the role of the orientation angle (  ) on the performance of the heat sink.  is varied from  0 to  360 by rotating the horizontal sink about a vertical axis passing through the center of the sink. A detailed CFD (computational fluid dynamics) study is coordinated over a wide range of inflow Reynolds number ( Re ) to explore the possibility for obtaining an optimum orientation angle (  ) for which Nusselt number ( Nu ) would be the maximum. Results indicate that optimum angle hovers around    120 regardless of the values of Re .

scholarly journals Experimental analysis of effect of base with different inner geometries filled nano PCM for the thermal performance of the plate fin heat sink

2021 ◽  
pp. 243-243
Author(s):  
Periyannan Lakshmanan ◽  
Saravanan Periyasamy ◽  
Mohan Raman
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Reynolds Number ◽  
Phase Shift ◽  
Experimental Research ◽  
Thermal Performance ◽  
Heat Sink ◽  
Electronic Devices ◽  
Base Plate ◽  
Heat Sinks

Experimental research demonstrates the performance of electronic devices on plate fin heat sinks in order to guarantee that operating temperatures are kept as low as possible for reliability. Paraffin wax (PCM) is a substance that is used to store energy and the aluminum plate fin cavity base is chosen as a Thermal Conductivity Enhancer (TCEs). The effects of PCM material (Phase shift material), cavity form base (Rectangular, Triangular, Concave and Convex) with PCM, Reynolds number (Re= 4000-20000) on heat transfer effectiveness of plate fin heat sinks were experimentally explored in this research. The thermal performance of concave base plate fin heat sink with PCM is increased up to 7.8% compared to other cavity base heat sinks.

Thermal Performance Analysis of Fan-Heat Sinks for CPU Cooling

2003 ◽  
Author(s):  
Seo Young Kim ◽  
Ralph L. Webb
Keyword(s):  
Thermal Resistance ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Sinks ◽  
Operating Point ◽  
Pin Fin ◽  
Flow Impedance ◽  
Impedance Curve ◽  
Convective Thermal ◽  
Offset Strip Fin

The thermal performance of plate fin, round pin-fin and offset strip-fin heat sinks with a duct-flow type fan arrangement was analytically evaluated. Heat sinks of 65mm × 60mm plan area × 50 mm height with a 4300-RPM DC fan (60mm × 15mm) were chosen for the performance comparison. A constant temperature, 6 mm thick heat sink base plate is assumed so that thermal spreading resistance is not involved. The operating point on the fan curve is based on the flow pressure drop impedance curve through a heat sink using the friction factor correlation for the chosen heat sink. The loss coefficients at both the entrance and the exit of heat sink are included in the flow impedance curve. The operating point is defined by the balance point of the flow impedance curve and the fan performance curve. After determining the operating air velocity, the convective thermal resistance of heat sinks is evaluated from the Nusselt number correlation for the chosen heat sink. Results obtained show that optimized round pin-fin heat sinks provide 32.8%-to-46.4% higher convective thermal resistance compared to an optimized plate-fin heat sink. The optimized offset strip-fin heat sink shows a slightly lower convective thermal resistance than the plate-fin heat sink. As the offset strip length decreases, however, thermal performance seriously deteriorates.

Multi Layer Micro Pin-Fins Heat Sinks for Better Performance

2010 ◽  
Author(s):  
T. J. John ◽  
B. Mathew ◽  
H. Hegab
Keyword(s):  
Temperature Distribution ◽  
Thermal Resistance ◽  
Heat Sink ◽  
Single Layer ◽  
Heat Sinks ◽  
Substrate Thickness ◽  
Pin Fin ◽  
Micro Channels ◽  
Pin Fins ◽  
Overall Performance

This study numerically investigates the feasibility and advantages of using a multilayer pin-fin heat sink to increase the overall performance of the heat sink. For the purpose of determining overall performance of the pin-fin heat sink a figure of merit (FOM) term is introduced in this paper, which constituted of both the thermal resistance and the pumping power of the heat sink. Higher the FOM of a heat sink better is its overall performance. A computational fluid dynamics software CoventorWARE™ is used for the analysis of micro heat sink performance. A small portion of the entire heat sink is modeled in this study assuming repeatability towards both sides for the ease of analysis. The developed models consist of two sections, the substrate (silicon) and the fluid (water at 278K). A uniform heat flux is applied to the base of the heat sink. A single layer micro pin-fin heat sinks with same dimensions as of the multi layer heat sink was also modeled for the comparison purpose. Temperature distribution at five different locations from the inlet to the outlet section is also analyzed to study the temperature distribution over the heat sink. Circular pin-fins were used in both the multilayer and single layer micro heat sinks. Feasibility of using micro channels as the second layer was also investigated in this paper and it proved to have advantages over using pin-fin structures on both layers. A geometric optimization based on the substrate thickness of the second layer of the double layer heat sink showed that the substrate thickness of the second layer doesn’t have any effect on the overall thermal resistance of the heat sink.

Parameter Optimization of a Micro Heat Sink With Circular Pin-Fins

2010 ◽  
Author(s):  
Mustafa Koz ◽  
Ali Kosar
Keyword(s):  
Experimental Data ◽  
Heat Sink ◽  
Stokes Equations ◽  
Numerical Models ◽  
Symmetry Plane ◽  
Heat Removal ◽  
Heat Sinks ◽  
Performance Criteria ◽  
Pin Fin ◽  
Pin Fins

Micro heat sinks have a broad applicability in many fields such as aerospace applications, micro turbine cooling, micro reactors electronics cooling and micro biological applications. Among different types of micro heat sinks, those with micro pin-fins are becoming popular due to their enhanced heat removal performance. However, relevant experimental data is still scarce and few optimization studies are present in the literature. In order to effectively optimize their performance an extensive parametric study is necessary and should be based on a realistic model. Moreover, micro pin fin heat sinks should be optimized according to appropriate performance criteria depending on the application. The objective of this paper is to fill the research gap in micro pin fin heat sink optimization based on realistic configurations. In this paper, the parameters for micro pin optimization are the pin-fin height over diameter ratio (0.5<H/D<5) and the longitudinal and transverse pitch ratios (1.5<(SL, ST)/D<5), while Reynolds number and heat flux provided from the base of the micro heat sink are in the range of (1<Re<100) and (20<q(W/cm2)<500) respectively. In this research micro pin fin heat sinks are three dimensionally modeled on a one-to-one scale with the use of commercially available software COMSOL Multiphasics 3.5a. Full Navier-Stokes equations subjected to continuity and energy equations are solved for stationary conditions. To have increased computational efficiency, half of the heat sink is modeled with the use of a symmetry plane. In order to validate the use of numerical models parametric values from previous experimental data available in the literature are exactly taken and simulated. The numerical and experimental results show a good agreement. After this validation optimization study is performed using the three dimensional numerical models.

Experimental and Numerical Analysis of Convective Heat Transfer From Notched Fin Arrays With Pin Fins

2013 ◽  
Author(s):  
Sunil V. Dingare ◽  
Suneeta S. Sane ◽  
Aniket H. Kawade ◽  
Hrishikesh N. Kulkarni ◽  
Kaustibh U. Suranglikar
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Temperature Difference ◽  
Heat Sink ◽  
Convection Heat Transfer ◽  
Heat Sinks ◽  
Central Portion ◽  
Pin Fin ◽  
Pin Fins ◽  
Free Convection Heat

In electronic components, it is essential to provide for adequate cooling to ensure that overheating does not affect the performance. It has been observed that for short fins, (L/H ≤ 5) due to formation of stagnant zone, central portion of fin is ineffective. To overcome this problem central portion from plate fin is removed. By doing so average heat transfer coefficient of notched array was improved almost by 30percentage compared to normal plate fin array. In this study we present computational assessment of notched plate fin heat sink (NPFHS) & notched plate fin pin fin heat sink (NPFPFHS). Based on NPFHS, a NPFPFHS is constructed which is composed of a NPFHS and some columnar pins planted between notched plate fins. Limited experimentation is carried out for validation of numerical model. Numerical analysis is carried out to compare thermal performance of these two types of heat sinks under the condition of equal temperature difference between mean sink temperature and ambient temperature. The effects of fin spacing, fin height, pin fin diameter and temperature difference between fin and surroundings on the free convection heat transfer from horizontal fin arrays were studied. The analysis have been carried out for the two types of heat sinks with three different spacing, three different height, four temperature differences and three pin diameters.

Thermal Performance of Triangular Folded Fin Heat Sinks in a Duct

2003 ◽  
Author(s):  
Seo Young Kim ◽  
Taeho Ji ◽  
Dong Gyu Choi ◽  
Byung Ha Kang
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Flow Velocity ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Thermal Performance ◽  
Heat Sink ◽  
Base Plate ◽  
Heat Sinks ◽  
Heat Transfer Characteristics

Experiments have been carried out to investigate the convective heat transfer characteristics from triangular folded fin heat sinks in a suction-type fan duct. The dimension of the triangular folded fin heat sinks is 62 mm in height with a 12 mm thick base plate, 292 mm in width, and 447 mm in length. The inlet flow velocity is varied in the range of 0.6–5.3 m/s. Thermal performance of triangular folded fin heat sinks is evaluated in terms of thermal resistance of heat sinks according to flow velocity and fan power. The results obtained show that the present triangular folded-fin heat sink shows a higher thermal performance compared to a conventional extruded plate-fin heat sink. Especially, a perforated slit folded-fin heat sink displays a lower thermal resistance. As the number of slit fabricated on the perforated folded fins increases, thermal performance is more pronounced.

Numerical Predictions of Thermal and Hydraulic Performances of Heat Sinks With Enhanced Heat Transfer Capability

2011 ◽  
Author(s):  
Feng Zhou ◽  
Nicholas Hansen ◽  
Ivan Catton
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Cross Section ◽  
Heat Sink ◽  
Heat Sinks ◽  
Pin Fin ◽  
Numerical Predictions ◽  
Pin Fins ◽  
New Type ◽  
Cross Section Profile

The plate-pin fin heat sink (PPFHS) is composed of a plate fin heat sink (PFHS) and some pin fins planted between the flow channels. In this paper, a numerical investigation was performed to compare the thermal and hydraulic performances of the PPFHSs and PFHS. PPFHSs with five forms of pin cross-section profiles (square, circular, elliptic, NACA 0050, and dropform) were numerically simulated. The influence of pin fin cross-section profile on the flow and heat transfer characteristics was presented by means of Nusselt number and pressure drop. It is found that the Nu number of a PPFHS is at least 35% higher than that of a PFHS used to construct the PPFHS at the same Reynolds number. Planting circular and square pins into the flow channel of heat sinks enhances the heat transfer at the expense of high pressure loss. Using the streamline shaped pins, not only the pressure drop of the compound heat sinks could be decreased considerably, the heat transfer enhancement also makes a step forward. The present numerical simulation provides original information of the influence of different pin-fin cross-section profiles on the thermal and hydraulic performance of the new type compound heat sink, which is helpful in the design of heat sinks.

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