Papers by Sreekant Narumanchi
Journal of Electronic Packaging, 2015
IEEE Transactions on Components, Packaging and Manufacturing Technology, 2016
ABSTRACT The thermal problem associated with the transient electrostatic discharge phenomena in s... more ABSTRACT The thermal problem associated with the transient electrostatic discharge phenomena in sub-micron silicon transistors is fast becoming a major reliability concern in IC packages. Currently, Fourier diffusion and some simple models based on the solution to the phonon Boltzmann transport equation (BTE) are used to predict failure (melting of silicon) in these transistors. In this study, a more comprehensive model, based on the phonon BTE and incorporating considerable details of phonon physics, is proposed and used to study the ESD problem. Transient results from the model reveal very significant discrepancies when compared to results from the other models in the literature.
International Journal of Heat and Mass Transfer, 2016
Int J Multiscale Comput Eng, 2005
Page 1. Review of Multi-Scale Simulation in Sub-Micron Heat Transfer Jayathi Y. Murthy , Sreekant... more Page 1. Review of Multi-Scale Simulation in Sub-Micron Heat Transfer Jayathi Y. Murthy , Sreekant VJ Narumanchi ¡ , Jose' A. Pascual-Gutierrez , Tianjiao Wang , Chunjian Ni and Sanjay R. Mathur ¢ School of Mechanical Engineering,Purdue University West Lafayette IN 47907 ...
Aps Meeting Abstracts, Mar 1, 2011
Efficient heat dissipation is critical for power electronics where the device package consists of... more Efficient heat dissipation is critical for power electronics where the device package consists of several layers of different materials. Conventional thermal interface materials are bottlenecks in heat removal. Detailed understanding of interfacial heat resistance would benefit efforts to improve the device design. We have chosen Si/Al interfaces for this thermal transport study. We construct Si-Al MEAM interatomic potential parameters based on the density functional theory (DFT) calculations. We generate various interface structures using the first-principles molecular dynamics (MD) simulations. Using the direct method to compute the thermal conductance, we investigated various interface structures. We will discuss the effect of the inter-diffused layers and roughness of the interfaces on the thermal boundary conductance. We will also compare our result with limited data in the literature.
International Journal of Heat and Mass Transfer, 2016
International Journal of Heat and Mass Transfer, 2015
The U.S. Department of Energy (DOE) FreedomCAR Program's technical targets for the electric t... more The U.S. Department of Energy (DOE) FreedomCAR Program's technical targets for the electric traction system (power electronics and electric machines) of advanced vehicles require significant reductions in volume, weight, and cost while also meeting performance and 15 year life requirements (1). The performance of the semiconductor switches and diodes, the ripple-current capability of the capacitors, and the life of the
ABSTRACT In modern microelectronics, where extreme miniaturization has led to feature sizes in th... more ABSTRACT In modern microelectronics, where extreme miniaturization has led to feature sizes in the sub-micron and nanoscale range, Fourier diffusion has been found to be inadequate for the prediction of heat conduction. Over the past decade, the phonon Boltzmann transport equation (BTE) in the relaxation time approximation has been employed to make thermal predictions in dielectrics and semiconductors at micron and nanoscales. This paper presents a review of the BTE-based solution methods widely employed in the literature. Particular attention is given to the problem of self-heating (hotspot) in sub-micron transistors. First, the solution approaches based on the gray formulation of the BTE are presented. In this class of solution methods, phonons are characterized by one single group velocity and relaxation time. Phonon dispersion is not accounted for in any detail. This is the most widely employed approach in the literature. The semi-gray BTE approach, moments of the Boltzmann equation, the lattice Boltzmann approach, and the ballistic-diffusive approximation are presented. Models which incorporate greater details of phonon dispersion are also discussed. This includes a full phonon dispersion model developed recently by the authors. This full phonon dispersion model satisfies energy conservation, incorporates the different phonon modes, and well as the interactions between the different modes, and accounts for the frequency dependence for both the phonon group velocity and relaxation times. Results which illustrate the differences between some of these models reveal the importance of developing models that incorporate substantial details of phonon physics.
A study was conducted to experimentally characterize the pool boiling performance of hydrofluoroc... more A study was conducted to experimentally characterize the pool boiling performance of hydrofluorocarbon HFC-245fa at pressures ranging from 0.15 MPa to 1.1 MPa (reduced pressure range: 0.04-0.31). Pool boiling experiments were conducted using horizontally oriented 1-cm 2 heated surfaces to quantify the effects of pressure and a microporousenhanced coating on heat transfer coefficients and critical heat flux (CHF) values. Results showed that the coating enhanced heat transfer coefficients and CHF by 430% and 50%, respectively. The boiling heat transfer performance of HFC-245fa was then compared with the boiling performance of HFC-134a and hydrofluoroolefin HFO-1234yf.
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Papers by Sreekant Narumanchi