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This paper is on a vertical through silicon via (TSV) fabrication method of integrated circuit (IC) packages. The vertical TSV processes are developed by evaluating different via depth and diameter. The stress simulation and analysis of the as-formed vertical TSV structure are also conducted to predict the possible mechanical failure during the reliability test.
Miniaturization and simultaneous increase of complexity and functionality of modern electronic control units (ECU) leads to the situation that the classical reliability methods become less and less sufficient. Reliability prediction in automotive industry is complex, as the load history on the system level (e.g. car) is multi-domain and depends on many different factors such as the climate, the type...
Copper in spite of being face centered cubic crystal has significant mechanical anisotropy. The elastic constants of copper vary considerably for different crystallographic orientations. Typically, the copper metal conductor lines in integrated circuits are polycrystalline in nature. The polycrystalline microstructure is known to impact the reliability and is yet to be thoroughly understood. In this...
This paper studies how the underfill with viscoelastic properties impacts the thermal mechanical reliability of a 3D-TSV package system. The Williams-Landel-Ferry equation and the relaxation modulus function in Prony series are used to characterize the viscoelasticity that is both temperature-dependent and time-dependent. The finite element model subjected to a thermal cycle consists of a four-layer...
Power semiconductor packages are prone to reliability issues related to microstructural changes, thermal fatigue and thermo-mechanical stresses during high temperature operation. This paper evaluates the reliability of various Pb-free Zn-Al-based solder alloys used as die-attached solder during thermal cycling aging. Minimal interfacial intermetallic compounds (IMCs) growth was observed after 1500...
This paper presents a study of the influences of DBC metal trace layout on the reliability of the high power IGBT module. The research is conducted on a seven-layer IGBT package model using finite element analysis simulation. A parametric study is carried out at different temperatures to simulate the thermal-cycling scenario. It shows in simulation that both total deformation and thermal stress are...
Polyimides (PI) and polybenzoxazoles (PBO) have good heat resistance, mechanical properties and electrical insulation. Therefore, they have been widely used as buffer coating and interlayer dielectrics with protection property for electric applications. Recently, fan-out wafer level package (FOWLP) has been attracting attention, because it has advantages of multi-pin, thinner and interposer-free....
In micro-electro-mechanical system devices, the thermal stress and deformation caused by ambient temperature variation are of great concern since they can directly affect the performance of the devices. This paper presents an optimized temperature robustness design for double-clamped micro-structures. Robust operation over temperature is a critical criterion for most MEMS sensors, however different...
The paper proposes a telemonitoring wearable system to be used by firefighters in dangerous missions. The current work is based on previous research of the authors conducted on heat and mental stress detection and on physiological parameters monitoring using wearable systems. A wearable garment was designed to monitor the wearer's physiological signals and the ambient conditions (temperature and humidity)...
This paper presents an initial study to provide further insight on the conditions under which a natural bar breakage was reproduced experimentally. With this aim several magnitudes at a rotor bar's narrowing (hot spot) in an induction motor during heavy transients: long startup and plug stopping, are calculated in order to compare it with the experimental data, which suggested that the bar breakage...
Mismatching operating conditions (due to clouds, shading, non-uniform aging, manufacturing tolerances, etc.) strongly limit the energetic efficiency and the reliability of PV plants. The dynamical re-configuration of PV modules represents a promising solution in order to mitigate the drawbacks associated to mismatching phenomena. The goal of this paper is just to prove that, by using the dynamical...
The mechanical strength of the thin dies especially with copper through-silicon via (Cu-TSV), has to be determined for ensuring good yield during manufacture handling and packaging. In this study, three test methods: a line-load on elastic-foundation (LoEF) test, a 3-point bending (3PB) test and a 4-point bending (4PB) test are used for the strength determination of Cu-TSV thin memory dies. The results...
This study investigates of the mechanical properties of wafer level chip scale package (WLCSP) without under bump metallurgy (UBM) layer which is defined as 3-mask WLCSP package. The mechanical properties of dielectric layer, such as Young's modulus and hardness, were measured by nanoindentation systems. Simple models were developed to simulate the thermal stress and predict the failure area. In this...
Inelastic thermal stress simulation was performed to evaluate effect of fiber cloths structures on thermal fatigue strength in through hole in PCB under cyclic thermal loads. Conclusions were shown as follows.
In this work, the 14 nm CPI (Chip and Package Interaction) challenges, development and qualification were investigated by using 130 um pitch Cu pillar bump in flip chip BGA package without heat spreader. We evaluated 14 nm BEOL film strength and adhesion in the torture tests. After passing the torture tests, the package is evaluated in the CPI reliability tests following the JEDEC standard. We optimized...
Several maximum power point tracking (MPPT) methods have been proposed to optimize the energy harvesting of photovoltaic systems. However, the optimization of the energy harvesting can produce extremely variable loading of the power semiconductors resulting in a decrease of the system lifetime. This work proposes a multi-objective MPPT for two-stage photovoltaic converters, where the semiconductor...
Many prior works have investigated electromigration (EM) on full-chip power grid interconnects, which has become one of major reliability concerns in nanometer VLSI design. However, most of the published results were obtained under the assumption of uniformly distributed temperature and/or residual stress across interconnects. In this paper, we demonstrate the implementation of novel methodology and...
This paper presents a novel piezoelectric sensor, which is integrated in power modules and analyzes temperature and thermal-mechanical stress in real time. Due to the increased power density, recent power modules are often exposed to high operating temperatures. Thus, it is critical to measure temperature and (related) thermal stress in power modules. The piezoelectric sensor proposed herein is fabricated...
A Smart Transformer (ST) can cover an important managing role in the future electrical distribution grid. For the moment, the reliability and cost are not competitive with traditional transformers and create a barrier for its application. This work conduct detail designs and analysis for a promising modular ST solution, which is composed of Modular Multi-level converter, Quad Active Bridge DC-DC converters,...
This paper deals with operational issues related to a 36-MVA, 11-kV synchronous motor used to drive a reciprocating compressor in a process industry. Extensive damage to the motor's damper winding was discovered during routine maintenance. The paper identifies possible operational issues that are believed to have contributed to the development of fault, presents a simplified analytical model of the...
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