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In the design process, modelling is a fundamental stage which allows the designer to obtain a general overview of the device performance. Very often, this phase is very time-consuming, especially if a well optimized device which fulfils very specific requirements is to be fabricated. Hence, a fast and reliable technique of simulation is needed and accurate tools have to be used to achieve this goal...
In this paper, a methodology is proposed for expediting the coupled electro-mechanical two-dimensional finite element modeling of electrostatically-actuated MEMS. The proposed methodology eliminates the need for repeated finite element meshing and subsequent electrostatic modeling of the device during mechanical deformation. With the reference domain defined to be the device geometry in the absence...
Two new designs for copper base heat sink is proposed in this work. In some experimental and numerical simulation efforts, optimizing and predicting of the thermal characterization of the heat sink with inclined free fins is developed.
In order to study the electrical-thermo-mechanical interaction in OLEDs, finite element based simulation models were developed. Two dimensional models were used to study detailed design effects, such as the location of the bus bars, while a three dimensional model was used to study the effect of differences between the two and three dimensional models, as well as bus bar designs.
This paper gives an overview of the different monolithic approaches to compute the pull-in curve for discretized models of electrostatically actuated microsystems that are currently available in the literature. A method to implement monolithic charge loading combined with path-following is proposed. The performance of the algorithms is tested with some numerical experiments: FEM models of microbeams,...
The lifetime of a solder joint is mainly determined by its creep behaviour. Creep arises from the stresses inside the solder joints as a consequence of the thermomechanical mismatch of the board and the substrate. The stress state is heavily influenced by the anisotropy of tin. To understand the damage process in solder joints, the influence of the anisotropic microstructure must be understood. In...
This paper presents a combined numerical and experimental methodology for predicting moisture-induced effects in Package-on-Package (PoP) assemblies. The hygroscopic warpage of the assembly "PoP" is measured. Its behavior is compared with the individual components "top" and "bottom". The assembly "PoP" absorbs more moisture than the sum of the two individual...
In this study, two highly filled molding compounds were used as example to demonstrate the characterization scheme. In addition, two low filled packaging polymers are included for comparison. The characterization scheme consists of the steps sample preparation, measurement of the material data, and modeling the material behavior. The dasiasample preparationpsila step included a DSC analysis to understand...
This paper investigates a method to decide which mechanical modes need to be retained in a modal truncation for a thermomechanical problem. A more efficient reduction basis is formed by looking into more detail in the modal participation of the different mechanical modes. Based on the spatial matching properties of mechanical modes with thermal modes can be decided which modes need to be retained...
Warpage of micro-electronics caused by the curing process and thermal cycling is of major importance in electronic packaging. Industry is availed by good methods to be able to predict warpage accurately. The main difficulty for prediction of warpage is caused by the complicated material behavior of molding compound. It turns out that the mechanical behavior of molding compound is dependent on time,...
In this paper we present a novel approach to determine material thermal properties of thin film materials. As a test case we have chosen silicon nitride employed in a micro-hotplate structure. We use ANSYS to build a three-dimensional finite element (FE) model of the test structure, which considers heat conduction and convection effects. It is further parameterized and subjected to parametric model...
Current developments and trends in microelectronics are focused on thin layers and novel materials. This leads to application of different test and measurement methods, which are capable to measure basic mechanical properties of such materials on micro-scale and nano-scale. The presented project focuses on application of the nanoindentation technique in order to extract the basic elastic and elasto-plastic...
We present a simplified model of mechanical behavior of large cantilever arrays with discoupled rows in the dynamic operating regime. Since the supporting bases are assumed to be elastic, cross-talk effect between cantilevers is taken into account. The mathematical derivation combines a thin plate asymptotic theory and the two-scale approximation theory, devoted to strongly heterogeneous periodic...
With the increased complexity of SiP (system in package), Finite Element simulations take an important role in predicting the thermo-mechanical package reliability. Failures in flip chip packages such as die cracking and fatigue of solder bumps are specially the result of the mismatch in thermal expansion coefficients between die and the substrate. In some packages, we use an underfill to improve...
This study presents a newly developed dynamic model established by MATLAB Simulink that can handle post pull-in behavior of MEMS electrostatic torsional mirror. In addition to the conventional MATLAB Simulink model of the quadratic oscillation system, a mathematical model of displacement limiter has been inserted to represent the pull-in effect in dynamic analysis. Due to the modification, the model...
Actuation, sensoring and control in arrays of MEMS require spatially distributed periodic electronic circuits. For very large sized arrays, say 1000 times 1000 MEMS or cells, on the same chip, simulation requirements for electronics are far away from standard algorithm capabilities. One of the authors has shown in a theoretical paper, that a homogenization modeling method, previously developed for...
The reliability of the electrostatically actuated MEMS contact switches is known to be significantly undermined by the unstable dynamic behaviour of devices. High impact forces, bouncing at the contact and oscillations upon release result in substantial mechanical damage to the contacts and the switch compromising the functionality of the switch and reducing its lifetime. Certain effects become more...
We present a computationally efficient multi-energy domain coupled system-level model of an electrostatically actuated RF-MEMS switch exposed to squeeze film damping. The physically-based model is systematically derived and calibrated on the basis of a hierarchical modeling approach. The model shows excellent agreement with both static and dynamic measurements performed with a white light interferometer...
Despite extensive research over the past decades, corrosion of aluminum bond pads is still a major reliability risk for plastic encapsulated microelectronics. Nowadays even an increase in susceptibility for corrosion is observed for new waferfab technologies and encapsulation materials during reliability tests. The recent trend for the new generation encapsulation materials is to decrease the glass...
Interfacial delamination, due to the presence of dissimilar material systems, is one of the primary concerns in electronic package design. Continuum models such as J-integral have been developed to evaluate potential delamination by defining a pre-defined crack at selected interface in the package. The interface is modeled as a discontinuity across the mating material layer. However, at molecular...
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