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In this paper both digital and liquid cooling concepts are proposed. Microchannel cooling techniques either actuated by a separate feed pump or actuated by electrowetting are investigated and their cooling capabilities and pumping requirements are assessed. Though the continuous liquid microchannel cooling clearly outperforms the other systems with respect to global thermal resistances, the low energy...
In the development of present and future CMOS-technologies (CMOS065 and beyond) for microelectronic components the combination of state-of-the-art modeling techniques and experimental testing is crucial and provides a challenge to address the thermo-mechanical reliability issues and the demand for shorter time-to-market by the industry. Nowadays these modeling techniques often involve the construction...
Interfacial failure, mainly in the form of debonding or delamination of brittle interfaces, is one of the major sources of failure in microsystems that consist of multiple thin and stacked layers, manufactured using different materials. A cohesive zone model with a simple traction- separation law is employed to simulate the benchmark test of pure mode I delamination in a double cantilever beam. A...
Simulation of micro-thrusters intended for space propulsion relies on accurate modeling of those physical processes that occur highly coupled in the micron-sized scale. In fact, micronozzles exhibit significant differences when compared to their large-scale counterparts, so their modeling requires accounting for specific aspects to achieve success in the prediction. The goal of the present investigation...
With the dramatic advances made in Microsystems industry, System-on-a-Package (SOP) technology holds promise in terms of reduction in size, cost, and improved performance. To be able to achieve such benefits in an integrated system, it is necessary not to compromise the overall reliability of the system. Therefore, the SOP technology will require up-front system-level design-for-reliability approaches...
The mechanical properties of copper thin films formed by cold-rolling and electroplating were compared using tensile test and nano-indentation. Both the Young's modulus and tensile strength of the films were found to vary drastically depending on the microstructure in the films. The Young's modulus of the cold-rolled film was almost same as that of bulk material. However, the Young's modulus of the...
Nowadays, one of the trends in microelectronic packaging is to integrate multi-functional systems into one package, resulting in more applications of highly dissimilar materials in the form of laminated thin films or composite structures. As a consequence, the number of interfaces increases. Often, the interface between these dissimilar materials is where the failure is most likely to occur especially...
Thermal simulation is the main thermal design tool used to predict temperature distributions of complex power electronics assemblies. Nevertheless, the validation of the simulation results remains a complex problem, mainly in dynamic operation, due to the difficulty in measuring semiconductor device temperatures. This paper proposes a methodology for the accurate validation of CFD 3-D thermal simulations...
To allow realistic stress assessments of BGA modules during drop and shock events, the dynamic mechanical behavior of SAC BGA solder joints was determined by a combination of fast shear tests and FEM simulations. The goal has been the development of a validated material model for SnAg1.0Cu0.5 BGA solder joints that accounts for dynamic material hardening and the dependency of the fracture mode on...
We investigate the shock-induced stress state and possible failure mechanisms in polysilicon MEMS sensors. In case of accidental drop events, we aim at highlighting the links between drop features, like drop height and impact angles, and the location of the failing detail of the device. Taking into account the small inertial contribution of the sensor to the whole package dynamics, we adopt a decoupled...
The current paper deals with firstly the optimized SMT to assemble various types of QFN (Quad Flat Non- leaded) packages. The important SMT factors such as solder pad and stencil designs will be discussed. Secondly and more importantly, this paper will detail the comprehensive experiment and simulation work done for QFN solder joint reliability modeling. A curve fitted fatigue correlation model together...
Initial studies have demonstrated that specially designed and fabricated microelectronics embedded in flexible substrates can maintain functionality when subjected to stretching as well as bending. The acceptable flexibility and stretchability for ultra-thin substrate could be reached by embedding the ultra-thin substrate into flexible polyimide and patterning the silicon into square or hexagon segmentations...
Among the various reliability related concerns in automotive and power electronics, electromigration in solder joints might be one of the least investigated degradation effects. It requires high current densities that usually only occur in small flip chip solder joints. Even if the current densities in power electronic components, like IGBTs (TO 263), cannot be compared with that in ultra small flip...
We present the conception of a micro pressure source for microfluidics applications. It consists in 3 main parts: (i) a heating resistance built on a dielectric membrane, (ii) an energetic material which decomposes generating a high volume of biocompatible gas, (iii) an elastomer membrane with high elastic properties. PDMS is chosen as the membrane material for its elastic properties. A bimetallic...
The creep behaviour of solders is an important input for accurate material models for FE-analysis of electronic assemblies. Usually the mechanical behaviour of solders, is been determined by tensile tests on bulk solder specimens. Although performing these tests is not complicated and the results are easy to interpret, one of the key problems lies in the fact that solder joints are very small and...
The scope of this study is to investigate the influences on the solidification of the micro structure of SnAgCu solders. It will be shown that the solidification process depends on solder composition, specimen size and manufacturing conditions. The influence of solder composition has been investigated on bulk solder ingots by varying the Ag content from 3.0 wt% to 3.8 wt% and the Cu content from 0...
Mechanical stiffness and density of III-V (GaAs) nanowire (NW) are studied by atomistic simulation in the <111>, <110> and <100> directions. Series of molecular models are established and mechanical characteristics of the crystal orientations are considered. The simulation results indicate that the NW exhibits highest structural stiffness in the <111> direction. We also found...
In this work, the potential use of a micromachined thermopile based device for analyzing natural gas is explored. Device's response is studied to attain the final goal of detecting variations in natural gas composition through the variation of its thermal conductivity. A FEM thermal model of the device is developed and used to simulate its thermal operation and estimate its sensitivity. Different...
With the application of a methodical modelling architecture, analysis of the effects of both design and manufacturing processes on life cycle expectancy and manufacturing yields can provide a platform for systems level reliability, enabling the prediction of product failure. However, the calculation reliability has been historically centred on physics-of-failure approaches (i.e. at the 'component...
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