Adhesion and delamination have been pervasive problems hampering the performance and reliability of micro-and nano-electronic devices. In order to understand, predict, and ultimately prevent interface failure in electronic devices, development of accurate, robust, and efficient delamination testing and prediction methods is crucial. Adhesion is essentially a multi-scale phenomenon: at the smallest scale possible, it is defined by the thermodynamic work of adhesion. At larger scales, additional dissipative mechanisms may be active which results in enhanced adhesion at the macroscopic scale and are the main cause for the mode angle dependency of the interface toughness. Undoubtedly, the macroscopic adhesion properties are a complex function of all dissipation mechanisms across the scales. Thorough understanding of the significance of each of these dissipative mechanisms is of utmost importance in order to establish physically correct, unambiguous, values of the adhesion properties, which can only be achieved by proper multi-scale techniques. The topic “Advances in Delamination Modeling” has been split into two separate chapters: this chapter discusses the atomistic aspects of delamination, while the preceding chapter deals with the atomistic aspects of interface separation. The chapter starts with a concise overview of molecular simulation strategies. Next, examples are provided which represent actual materials being developed for electronic packaging: (1) the prediction of thermomechanical properties of an epoxy molding compound (EMC) and the adhesion properties of an EMC/copper interface by means of MD and CG MD approaches; (2) the modeling of wetting, adhesion, and reliability cycling of die attach and via fills; (3) model scaling to discrete element modeling (DEM) for understanding underfill flow; (4) CG modeling of an epoxy molding compound which relates to the first example; (5) molecular modeling of silicate layers used in planarization and encapsulant layers for flat panel displays; (6) mesoscale modeling of diffusion of organic bases which is of concern to photoresist poisoning; and (7) the prediction of thermomechanical properties of a low-k dielectric material, SiOC:H. ... Read more

Lumen depreciation is one of the major failure modes in light-emitting diode (LED) systems. It originated from the degradation of the different components within the package, being the LED device or chip, the driver, and the optical materials (including phosphorous layer). This chapter describes the state of the art of the degradation mechanism for these components and how they contribute to the lumen depreciation of the LED package as a whole. ... Read more

We report a molecular modeling study to evaluate and select conducting polymers (CPs) for use as the sensing layer for carbon dioxide (CO2) sensor. The interactions between gases and sensing materials and the adsorptions of small gas molecules on polymer sensing films are described and investigated. Polymers considered for this work include emeraldine base polyaniline (EB-PANI) and unprotonated sodium polyaniline salt (NaSPANI) with sulfur to nitrogen ration (S/N) of 0.4, 0.5 and 0.6 Gases studied include CO2, humidity (H2O). Comparative studies of NaSPANI and PANI show differences on the polymer-gas interaction energy and gas sorption number because of the -So3NA groups on the phenyl rings. ... Read more

High Power RF electronics is one of the essential parts for wireless communication, including the personal communication, broadcasting, microwave radar, etc. Moreover, high efficient high power electronics has entered the ISM market, such as the power generator of microwave oven. ... Read more

Lighting is an advancing phenomenon both on the technology and on the market level due to the rapid development of the solid state lighting technology. The efforts in improving the efficacy of high brightness LED's (HB-LED) have concentrated on the packaging architecture. Packaging plays a significant role in reliability; not only on mechanical protection but also on thermal management. An efficient numerical model using the finite element technique to evaluate thermal and mechanical performance of LED packaging is presented in this article. A commercial HB-LED package is used as a benchmark example and a strategy relying on the obtained thermo-mechanical response to reduce the mesh size and density is proposed. Next, two new HB-LED concepts are simulated based on the proposed finite element modeling strategy. ... Read more

Molecular dynamics (MD) and molecular mechanical (MM) analysis are carried out to provide reliable and accurate model for emeraldine base polyaniline. This study validate the forcefields and model with the physical and mechanical properties of the polyaniline. The temperature effects on non-bond energy, potential energy and solubility parameter during the transformation from the rubbery to the glassy state have been analysed in this work. A new method using the solubility versus temperature (delta-T) curve for predicting the Tg of polymer are suggested. Keywords: Emeraldine base; molecular dynamics; forcefields; glass transition. ... Read more