Since its inception 20 years ago, ITherm, The Intersociety Conference on Thermal, Mechanical, and Thermomechanical Phenomena in Electronic Systems, has been addressing recent advances in the area of thermal management, mechanical, and thermomechanical issues in electronic packages and systems. The conference has enjoyed the support of IEEE CPMT Society, which is its prime sponsor, and the ASME Heat Transfer Division's K-16 Committee on Cooling of Electronic Equipment. During these 20 years, ITherm has steadily grown and maintained a good balance of papers presented in the areas of thermal, mechanical, and emerging technologies. It has become a practice to publish selected papers from ITherm conferences in IEEE Transactions Components and Packaging Technologies. For the first time some of these papers are published in the Journal of Electronic Packaging with contributions from Thermal Management and Emerging Technologies Tracks of ITherm 2004. Of the 14 papers originally invited, 11 appear in this issue after peer review. A brief summary of these papers follows.

The lead paper in this issue is a keynote paper by Goodson and Pop at ITherm 2004. In this paper, the authors have reviewed the impact of material properties and geometries on subcontinuum thermal modeling in transistor devices and examined its implications to thermal cooling of electronic systems. Ju has reported measurements of thermal resistance and a theoretical study of subcontinuum heat generation in tunnel junctions, a key element in spintronics. A nanoscale heating scheme has been proposed with implications to magnetic random access memory devices. Escobar et al. have reported an investigation into subcontinuum energy transport in crystalline and non-crystalline semiconductor materials by solving the lattice-Boltzmann equation for phonon transport using the lattice-Boltzmann method. Shojaei-Zadeh et al. have measured thermal conductivity of 100–500 μ m thick film diamond-like dielectric materials using a novel film-on-substrate technique. Gowda et al. have reported detailed failure analysis and microstructural characterization of filled thermal interface materials used between a silicon die and a heat sink/spreader. Boucher et al. have examined possible approaches for improving thermal management and energy performance of data centers with automatic control. Experimental results demonstrating implementation of modular control strategies are presented. Based on these, strategies are proposed for improving the energy efficiency of the data center while maintaining proper thermal management. Tillery et al. have discussed a method for delaying the onset of the critical heat flux whereby a vibration-induced jet is used to dislodge vapor bubbles during nucleate boiling. An experimental study, incorporating flow visualization, is used to examine the effect of this technique for maximizing surface heat fluxes in thermal test dies of fixed temperature. Rundstrom and Moshfegh have presented a steady state, 3D numerical model for the simulation of a high velocity impinging air, jet flow in combination with low velocity channel flow. The authors discuss the merits of both impingement flow and channel flow with respect to which face of the cube sees the high velocity impingement stream. Teertstra et al. have developed an analytical model for natural convection heat transfer from an isothermal single printed circuit board to its enclosure by combining the limiting cases of conduction in the enclosure, laminar, and transitional flow cases. Predictions of the analytical model favorably compare with the CFD results. Sansoucy et al. have reported experimentally measured heat transfer rates from a parallel plate heat sink under a turbulent impinging air jet for a range of Reynolds numbers and two values of nozzle-to-plate spacing. The results have also been compared with previously published numerical results. Prstic and Bar-Cohen have numerically and experimentally investigated the effect of a heat shield, a thin metal sheet placed around a partially shrouded heat sink. The results show that one can achieve heat transfer and pressure drop values with a heat shield comparable to a fully shrouded heat sink.

The Executive Committee and the Organizers of past and present ITherm conferences mourn the loss of Mr. Paul A. Baltes and Prof. Gary Lehmann. These individuals have made sustained contributions to the growth and success of ITherm conferences.

The Guest Editors of this Special Issue gratefully acknowledge the assistance of the following reviewers: Gamal Refai-Ahmed, Frank Andros, Mehmet Arik, Majid Bahrami, Mulugeta Berhe, Sushil H. Bhavnani, Victor Adrian Chiriac, David W. Copeland, J. Richard Culham, Timothy S. Fischer, Jen-Dong Hwang, Masaru Ishizuka, Satish G. Kandlikar, Kailash Karki, Gary Lehmann, Jennifer R. Lukes, Ravi Mahajan, Jay M. Ochterbeck, Ravi S. Prasher, K. Ramakrishna, B. G. Sammakia, Roger Schmidt, Sanjiv Sinha, S. C. Yao, and Z. W. Zhong. We acknowledge Paul Wesling, VP, Technical Publications, IEEE CPMT Society and the IEEE for granting copyright of these papers to ASME. Last, but not least, we acknowledge Gary Miller, Editorial Assistant, Journal of Electronic Packaging, for his constant help with many logistics involved in bringing out this Special Issue.