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ME381R Lecture 1 Overview of Microscale Thermal Fluid Sciences and Applications. Dr. Li Shi Department of Mechanical Engineering The University of Texas at Austin Austin, TX 78712 www.me.utexas.edu/~lishi lishi@mail.utexas.edu. Microprocessor Evolution. Localized Heating in VLSI Chips.
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ME381R Lecture 1 Overview of Microscale Thermal Fluid Sciences and Applications Dr. Li Shi Department of Mechanical Engineering The University of Texas at Austin Austin, TX 78712 www.me.utexas.edu/~lishi lishi@mail.utexas.edu
Localized Heating in VLSI Chips DT=20C Mean-time-to-failure due to electromigration increase x5 80C 90C 108C Dependence of mean time between failure on temperature 110C 1 cm On chip temperature contour Steve Kang et al. Electrothermal analysis of VLSI Systems, Kluwer 2000
Telecommunication Data Rate Evolution 1.00 GB Hard Drive 1.44MB Floppy Disk Howard Banks, "Life at 100 billion bits per second", Forbes Magazine, Oct. 6, 1997
Thermal Issues in Optoelectronic Integrated Circuits Affolter, WDM Solutions (supplement to Laser Focus World), P.65 June 2001, www.wdm-solutions.com A. Shakouri, J. Christofferson, Z. Bian, and P. Kozodoy, “High Spatial Resolution Thermal Imaging of Multiple Section Semiconductor Lasers,” Proceeding of Photonic Devices and System Packaging Symposium (PhoPack 2002), pp22-25, July 2002, Stanford CA.
IC Thermal Management Challenge Courtesy: Prof. Ken Goodson, DARAPA Thermal Management Workshop
Marlow Single-Stage Thermoelectric cooler Thermoelectric Refrigeration • Optoelectronics • Electronics • Consumer • Automobile • No moving parts: quiet • No CFC: clean • Low efficiency
Efficient Thin Film Thermoelectric CoolersVenkatasubramanian et al, Nature413, P. 597 (2001) Thin film superlattice
How far exponential growth in electronics and fiber optics can continue? Airplane Speed- Past, Present, Future McMasters & Cummings, Journal of Aircraft, Jan-Feb 2002 The brick wall due to heating, fabrication cost, quantum mechanics … Future challenges & opportunities: transportation, communication, energy, health care …
Direct Thermal to Electric Energy Conversion • Electric power generator with no moving part • Power sources for NASA space probe • NAVY Electric Ships (Seapower 21) • Waste heat recovery (cars, power plants, …) • Microscale power sources Efficient Nanostructured Thermoelectric Power Generator Spacecraft Power Source
Microfluidic Chip for Continuous Glucose Monitoring(J. Zahn et al.)
Length Scale 1 km Aircraft Automobile 1 m Human Computer Butterfly 1 mm Fourier’s law, Novier-Stokes Microprocessor Module MEMS Blood Cells 1 mm Wavelength of Visible Light Particle transport theories, molecular dynamics… l Microprocessor, NEMS 100 nm Nanotubes, Nanowires 1 nm Width of DNA
Fourier’s Law for Heat Conduction Thermal conductivity Q (heat flow) Hot Th Cold Tc L
Microscopic Origins of Thermal Fluid Transport --The Particle Nature MaterialsDominant energy carriers Gases: Molecules Metals: Electrons Insulators: Phonons (crystal vibration) L Hot Cold In micro-nano scale thermal fluid systems, often L < mean free path of collision of energy carriers & Fourier’s law breaks down Particle transport theories or molecular dynamics methods