event
Friday 25 May 2012: Multiphysics, Multiscale, Material Behavior in Electronic Systems
Professor Abhijit Dasgupta (University of Maryland) -
Harrison 170 (3D Visualisation Suite) 14:00-15:00
Materials in electronic systems have to be optimized for multiple functions. Properties of interest include semiconductor properties (I-V curves), dielectric constants, electrical and thermal conductivity, thermal expansion coefficients, mechanical stiffness and strength, inelastic deformation behavior (e.g. plasticity and creep), phase change temperature (melt temperature, glass transition temperature, etc.). Many of these materials are highly heterogeneous with multiple intrinsic internal length scales. Examples include: semiconductors with dopants for optimal semiconductor properties; metal traces in ICs with tailored grain boundaries for reduced electromigration; metallic alloys with nanoscale and microscale intermetallic reinforcements used for soldering applications; molding compounds consisting of filled polymers with tailored mechanical and thermal properties; conductive adhesives with electrically conducting filler particles; fabric-reinforced polymer composites used in organic substrates; electrolytes and composite electrode materials optimized for coupled electro-chemistry and thermo-mechanical behavior for battery applications. Furthermore, the characteristic structural length scale in electronic systems can range all the way from nanometers to millimeters. This presentation will provide overviews of a few examples, to demonstrate multiscale and coupled-physics approaches that are required for optimizing the performance and durability of electronic systems:
+ multi-scale analysis of the creep resistance and interfacial strength of lead-free solder interconnects
+ ‘cold welding’ as an interfacial bonding mechanism, in adhesively bonded electrical interconnects
+ thermo-mechanical and hygromechanical durability issues in underfilled flip-chip assemblies
+ optimization of dielectric, thermal and mechanical behavior of fabric composites for organic substrates in electronic assemblies
+ piezoelectric analysis of laminated shells
+ approach for combining electro-chemistry with thermo-mechanical analysis for Li-ion batteries
Bio: Abhijit Dasgupta conducts his research on the mechanics of engineered, heterogeneous, active materials, with special emphasis on the micromechanics of constitutive and damage behavior. He applies his expertise to several multifunctional material systems, including electronic packaging material systems, and "smart" composite material systems. His research contributions include solution techniques for coupled boundary value problems in multifunctional particulate and laminated composites, micromechanics approaches for constitutive properties of advanced 3-D composites, dynamic behavior and failure of thick composites, micromechanics of fatigue damage in viscoplastic eutectic-alloy composites and in short-fiber polymeric composites, and self-health monitoring in "smart" systems. He applies these principles for developing effective virtual qualification tools, for optimizing manufacturing process windows, for real-time health monitoring and for devising quantitative accelerated testing strategies used in qualification and quality assurance of complex electronic, electromechanical and structural systems. He has published over 150 journal articles and conference papers on these topics, presented over 20 short workshops nationally and internationally, served on the editorial boards of three different international journals, organized several national and international conferences, and received six awards for his contributions in materials engineering research and education. He has worked in the industry prior to academia at Tata Motors and obtained the PhD from the University of Illinois at Urbana-Champaign in 1989. He is a core faculty member at CALCE.
