VLSI Hotspot Cooling Using Two-Phase Microchannel Convection

2002 ◽  
Author(s):  
Jae-Mo Koo ◽  
Sungjun Im ◽  
Eun Seok Cho ◽  
Ravi S. Prasher ◽  
Evelyn Wang ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Heat Sink ◽  
Junction Temperature ◽  
Microchannel Heat Sink ◽  
Signal Delay ◽  
Two Phase ◽  
Silicon Chips ◽  
Vlsi Chip ◽  
Spatially Varying ◽  
The Impact

Two-phase microchannel heat sinks are promising for the cooling of high power VLSI chips, in part because they can alleviate spatial temperature variations, or hotspots. Hotspots increase the maximum junction temperature for a given total chip power, thereby degrading electromigration reliability of interconnects and inducing strong variations in the signal delay on the chip. This work develops a modeling approach to determine the impact of conduction and convection on hotspot cooling for a VLSI chip attached to a microchannel heat sink. The calculation approach solves the steady-state two-dimensional heat conduction equations with boundary conditions of spatially varying heat transfer coefficient and water temperature profile. These boundary conditions are obtained from a one-dimensional homogeneous two-phase model developed in previous work, which has been experimentally verified through temperature distribution and total pressure drop measurements. The new simulation explores the effect of microchannels on hotspot alleviation for 20 mm × 20 mm silicon chips subjected to spatially varying heat generation totaling 150 W. The results indicate that a microchannel heat sink of thickness near 500 μm can yield far better temperature uniformity than a copper spreader of thickness 1.5 mm.

Two-Phase Flow in Microchannels

2001 ◽  
Author(s):  
G. Hetsroni ◽  
A. Mosyak ◽  
Z. Segal
Keyword(s):  
Heat Sink ◽  
High Speed ◽  
Single Phase ◽  
Flow Boiling ◽  
Electronics Cooling ◽  
Working Fluid ◽  
Microchannel Heat Sink ◽  
Two Phase ◽  
Infrared Radiometry ◽  
Phase Water

Abstract Experimental investigation of a heat sink for electronics cooling is performed. The objective is to keep the operating temperature at a relatively low level of about 323–333K, while reducing the undesired temperature variation in both the streamwise and transverse directions. The experimental study is based on systematic temperature, flow and pressure measurements, infrared radiometry and high-speed digital video imaging. The heat sink has parallel triangular microchannels with a base of 250μm. According to the objectives of the present study, Vertrel XF is chosen as the working fluid. Experiments on flow boiling of Vertrel XF in the microchannel heat sink are performed to study the effect of mass velocity and vapor quality on the heat transfer, as well as to compare the two-phase results to a single-phase water flow.

Numerical Investigation of Flow Boiling in a Manifold Microchannel Heat Sink With Conjugate Heat Transfer

2019 ◽  
Author(s):  
Zhichuan Sun ◽  
Yang Luo ◽  
Junye Li ◽  
Wei Li ◽  
Jingzhi Zhang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Investigation ◽  
Heat Sink ◽  
Conjugate Heat Transfer ◽  
Flow Boiling ◽  
High Heat Flux ◽  
Microchannel Heat Sink ◽  
Two Phase ◽  
Boiling Process ◽  
Manifold Microchannel

Abstract The manifold microchannel heat sink receives an increasing number of attention lately due to its high heat flux dissipation. Numerical investigation of boiling phenomena in manifold microchannel (MMC) heat sinks remains a challenge due to the complexity of fluid route and the limitation of numerical accuracy. In this study, a computational fluid dynamics (CFD) approach including subcooled two-phase flow boiling process and conjugate heat transfer effect is performed using a MMC unit cell model. Different from steady-state single phase prediction in MMC heat sink, this type of modeling allows for the transient simulation for two-phase interface evolution during the boiling process. A validation case is conducted to validate the heat transfer phenomenon among three phases. Besides, this model is used for the assessment of the manifold dimensions in terms of inlet and outlet widths at the mass flux of 1300 kg/m2·s. With different ratios of inlet-to-outlet area, the thermal resistances remain nearly stable.

A Numerical Model for Oil Film Flow in an Aero-Engine Bearing Chamber and Comparison With Experimental Data

2004 ◽  
Author(s):  
Mark Farrall ◽  
Kathy Simmons ◽  
Stephen Hibberd ◽  
Philippe Gorse
Keyword(s):  
Experimental Data ◽  
Boundary Conditions ◽  
Roller Bearing ◽  
Numerical Approach ◽  
Oil Droplets ◽  
Two Phase ◽  
Oil Film ◽  
Aero Engine ◽  
The Impact ◽  
Engine Bearing

The work presented forms part of an on-going investigation, focusing on modelling the motion of a wall oil film present in a bearing chamber and comparison with existing experimental data. The film is generated through the impingement of oil droplets shed from a roller bearing. Momentum resulting from the impact of oil droplets, interfacial shear from the airflow, and gravity cause the film to migrate around the chamber. Oil and air exit the chamber at scavenge and vent ports. A previously reported numerical approach to the simulation of steady-state two-phase flow in a bearing chamber, that includes in-house sub-models for droplet-film interaction and oil film motion, has been extended. This paper includes the addition of boundary conditions for the vent and scavenge together with a comparison to experimental results obtained from ITS, University of Karlsruhe. The solution is found to be sensitive to the choice of boundary conditions applied to the vent and scavenge.

3D IC With Embedded Microfluidic Cooling: Technology, Thermal Performance, and Electrical Implications

2015 ◽  
Author(s):  
Xuchen Zhang ◽  
Xuefei Han ◽  
Thomas E. Sarvey ◽  
Craig E. Green ◽  
Peter A. Kottke ◽  
...  
Keyword(s):  
Heat Sink ◽  
Single Phase ◽  
Electrical Performance ◽  
Thermal Testing ◽  
Two Phase ◽  
Cooling Technology ◽  
Silicon Vias ◽  
The Impact ◽  
Measured Pressure ◽  
The Heat Transfer Coefficient

In this paper, a novel thermal testbed with an embedded micropin-fin heat sink is designed and fabricated. The micropin-fin array has a nominal height of 200 μm and a diameter of 90 μm. Single phase and two phase thermal testing of the micropin-fin array heat sink are performed using deionized (D.I.) water as the coolant below atmospheric pressure. The measured pressure drop is as high as 100 kPa with a mass flux of 1637 kg/m2s at a heat flux of 400 W/cm2 in a two-phase regime. The heat transfer coefficient and the vapor quality are calculated and reported. The impact of microfluidic cooling on the electrical performance of the 3D interconnects is also analyzed. The high aspect ratio through silicon vias (TSVs) used in the electrical analysis have a nominal diameter of 10 μm.

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