TCPT-2006-096.R2: Micro Scale pin fin Heat Sinks —Parametric Performance Evaluation Study
27 Nov 2007-IEEE Transactions on Components and Packaging Technologies (IEEE)-Vol. 30, Iss: 4, pp 855-865
TL;DR: In this paper, a parametric study of heat transfer and pressure drop associated with forced flow of deionized water over five micro pin fin heat sinks of different spacing, arrangements, and shapes was conducted experimentally.
Abstract: A parametric study of heat transfer and pressure drop associated with forced flow of deionized water over five micro pin fin heat sinks of different spacing, arrangements, and shapes was conducted experimentally. Nusselt numbers and friction factors were obtained over Reynolds numbers ranging from 14 to 720. The thermal and hydraulic results were obtained to evaluate and compare the heat sinks performances at fixed mass flow rate, fixed pressure drop, and fixed pumping power. Two distinct regions of the Nusselt number dependency on the Reynolds number separated by a critical Reynolds number have been identified for unstreamlined pin fin devices while the streamlined device showed no slope change. The effects of spacing, shape of pin fins, and arrangement on friction factor and heat transfer were in agreement with existing literature. The results indicate that utilizing streamlined pin fin heat sinks can significantly enhance the thermal-hydraulic performance of the heat sink, but only at moderate Reynolds numbers.
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02 Oct 2008-Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems
TL;DR: In this paper, the heat-removal capability of area-interconnect-compatible interlayer cooling in vertically integrated, high-performance chip stacks was characterized with de-ionized water as coolant.
Abstract: The heat-removal capability of area-interconnect-compatible interlayer cooling in vertically integrated, high-performance chip stacks was characterized with de-ionized water as coolant. Correlation-based predictions and computational fluid dynamic modeling of cross-flow heat-removal structures show that the coolant temperature increase due to sensible heat absorption limits the cooling performance at hydraulic diameters ≤200 μm. An experimental investigation with uniform and double-side heat flux at Reynolds numbers ≤1,000 and heat transfer areas of 1 cm2 was carried out to identify the most efficient interlayer heat-removal structure. The following structures were tested: parallel plate, microchannel, pin fin, and their combinations with pins using in-line and staggered configurations with round and drop-like shapes at pitches ranging from 50 to 200 μm and fluid structure heights of 100–200 μm. A hydrodynamic flow regime transition responsible for a local junction temperature minimum was observed for pin fin in-line structures. The experimental data was extrapolated to predict maximal heat flux in chip stacks having a 4-cm2 heat transfer area. The performance of interlayer cooling strongly depends on this parameter, and drops from >200 W/cm2 at 1 cm2 and >50 μm interconnect pitch to <100 W/cm2 at 4 cm2. From experimental data, friction factor and Nusselt number correlations were derived for pin fin in-line and staggered structures.
161 citations
28 May 2008
TL;DR: In this article, the heat removal capability of area-interconnect-compatible interlayer cooling in vertically integrated, high-performance chip stacks was characterized with de-ionized water as coolant.
Abstract: The heat removal capability of area-interconnect-compatible interlayer cooling in vertically integrated, high-performance chip stacks was characterized with de-ionized water as coolant. Correlation-based predictions and computational fluid dynamic modeling of cross-flow heat-removal structures show that the coolant temperature increase due to sensible heat absorption limits the cooling performance at hydraulic diameters les 200 mum. An experimental investigation with uniform and double-side heat flux at Reynolds numbers les 1000 and heat transfer areas of 1 cm2 was carried out to identify the most efficient interlayer heat-removal structure. Parallel plate, microchannel, pin fin, and their combinations with pins using in-line and staggered configurations with round and drop-like shapes at pitches ranging from 50 to 200 mum and fluid structure heights of 100 to 200 mum were tested. A hydrodynamic flow regime transition responsible for a local junction temperature minimum was observed for pin fin inline structures. The experimental data was extrapolated to predict maximal heat flux in chip stacks with a 4-cm2 heat transfer area. The performance of interlayer cooling strongly depends on this parameter, and drops from >200 W/cm2 at 1 cm2 and >50 mum interconnect pitch to <100 W/cm2 at 4 cm2.
145 citations
Cites background or methods from "TCPT-2006-096.R2: Micro Scale pin f..."
...Low-aspectratio pin fin heat-transfer structures at Reynolds (Re) numbers 1000 were analyzed by other groups, but only using singleside heat flux with a glass cover on the cavity [10] [11] [12], a configuration that does not reflect the double-side heat transfer in interlayer forced convection....
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...The DPF has slightly lower pressure needs, even with smaller hydraulic diameter and larger wetted surface area, but reduced flow separation, as discussed in [12]....
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TL;DR: In this article, a geometry optimization method was proposed to enhance the cooling performance of the micro square pin-fin heat sink, which is characterized by low thermal resistance, compact structure and uniform temperature distribution along the flow direction.
143 citations
TL;DR: In this article, four types of staggered micro pin fin with different cross-section shapes, i.e., square, circular, diamond and streamline, were fabricated by a laser micromilling method, and constructed for heat sinks cooling systems.
101 citations
TL;DR: In this paper, a flow visualization of 1-methoxyheptafluoropropane (HFE 7000) in 222 μm hydraulic diameter channels containing a single row of 24 inline 100 μm pin fins was studied.
Abstract: Flow boiling of 1-methoxyheptafluoropropane (HFE 7000) in 222 μm hydraulic diameter channels containing a single row of 24 inline 100 μm pin fins was studied for mass fluxes from 350 kg/m2 s to 827 kg/m2 s and wall heat fluxes from 10 W/cm2 to 110 W/cm2. Flow visualization revealed the existence of isolated bubbles, bubbles interacting, multiple flow, and annular flow. The observed flow patterns were mapped as a function of the boiling number and the normalized axial distance. The local heat transfer coefficient during subcooled boiling was measured and found to be considerably higher than the corresponding single-phase flow. Furthermore, a thermal performance evaluation comparison with a plain microchannel revealed that the presence of pin fins considerably enhanced the heat transfer coefficient.
91 citations
References
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Journal Article•
7,568 citations
"TCPT-2006-096.R2: Micro Scale pin f..." refers methods in this paper
...The uncertainties of the measured values, given in Table II, were obtained from the manufacturer’s specification sheets, while the uncertainties of the derived parameters were calculated using the method developed by Kline and McClintock [ 13 ], and the comparison of the experimental data with theory was accomplished through the mean absolute error (MAE), defined as...
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TL;DR: In this paper, a water-cooled integral heat sink for silicon integrated circuits has been designed and tested at a power density of 790 W/cm2, with a maximum substrate temperature rise of 71°C above the input water temperature.
Abstract: The problem of achieving compact, high-performance forced liquid cooling of planar integrated circuits has been investigated. The convective heat-transfer coefficient h between the substrate and the coolant was found to be the primary impediment to achieving low thermal resistance. For laminar flow in confined channels, h scales inversely with channel width, making microscopic channels desirable. The coolant viscosity determines the minimum practical channel width. The use of high-aspect ratio channels to increase surface area will, to an extent, further reduce thermal resistance. Based on these considerations, a new, very compact, water-cooled integral heat sink for silicon integrated circuits has been designed and tested. At a power density of 790 W/cm2, a maximum substrate temperature rise of 71°C above the input water temperature was measured, in good agreement with theory. By allowing such high power densities, the heat sink may greatly enhance the feasibility of ultrahigh-speed VLSI circuits.
4,214 citations
"TCPT-2006-096.R2: Micro Scale pin f..." refers background in this paper
...However, it is useful first to present the concept of total thermal resistance, which is often employed to evaluate the performance of micro scale heat sinks [12], [28], [29], [30]....
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...The total thermal resistance ( ) can be expressed [11], [12] as the sum of three components that account for conduction through the silicon substrate excluding the fin region ( ), convection to the flow ( ), and thermal resistance due to an increase in the flow temperature as it flows through the fins and absorbs heat ( )....
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TL;DR: In this paper, the authors discuss the heat transfer and the hydraulic resistance of single tubes, and the banks of tubes of various arrangements in flows of gases and viscous liquids, and highlight the influence of the physical properties of fluids on heat transfer.
Abstract: Publisher Summary This chapter discusses the heat transfer and the hydraulic resistance of single tubes, and the banks of tubes of various arrangements in flows of gases and viscous liquids. The focus is on the important problems of the heat transfer and the hydraulic resistance of tubes, in particular with the heat transfer of single tubes, banks of tubes, and systems of tubes in crossflow. The chapter also highlights the influence of the physical properties of fluids on heat transfer. Extensive experimental data will be analyzed and will include investigations of banks of tubes of various arrangements, and a single tube in crossflow in the range of Prandtl number from 0.7 to 500 and that of Reynolds number from 1 to 2xl0 6 .
1,181 citations
"TCPT-2006-096.R2: Micro Scale pin f..." refers result in this paper
..., )] at Reynolds numbers lower than are significantly higher than those of large scale correlations, at Reynolds numbers higher than the values are general in agreement with those obtained from long tubes [7], [14], [15]....
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...This is in agreement with previous conventional scale [15], [20] and micro-scale [20] studies....
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TL;DR: In this article, the authors investigated heat transfer and pressure drop phenomena over a bank of micro pin fin and found that very low thermal resistances are achievable using a pin fin heat sink.
419 citations
"TCPT-2006-096.R2: Micro Scale pin f..." refers background in this paper
...The total thermal resistance ( ) can be expressed [11], [12] as the sum of three components that account for conduction through the silicon substrate excluding the fin region ( ), convection to the flow ( ), and thermal resistance due to an increase in the flow temperature as it flows through the fins and absorbs heat ( )....
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TL;DR: In this article, the equations governing the fluid dynamics and combined conduction/convection heat transfer in a heat sink are presented in dimensionless form for both laminar and turbulent flow.
Abstract: The equations governing the fluid dynamics and combined conduction/convection heat transfer in a heat sink are presented in dimensionless form for both laminar and turbulent flow. A scheme presented for solving these equations permits the determination of heat sink dimensions that display the lowest thermal resistance between the hottest portion of the heat sink and the incoming fluid. Results from the present method are applied to heat sinks reported by previous investigators to study effects of their restrictions regarding the nature of the flow (laminar or turbulent), the ratio of fin thickness to channel width, or the aspect ratio of the fluid channel. Results indicate that when the pressure drop through the channels is small, laminar solutions yield lower thermal resistance than turbulent solutions. Conversely, when the pressure drop is large, the optimal thermal resistance is found in the turbulent region. With the relaxation of these constraints, configurations and dimensions found using the present procedure produce significant improvement in thermal resistance over those presented by all three previous studies. >
407 citations
"TCPT-2006-096.R2: Micro Scale pin f..." refers background in this paper
...However, it is useful first to present the concept of total thermal resistance, which is often employed to evaluate the performance of micro scale heat sinks [12], [28], [29], [30]....
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