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Thermal cycling accelerated life testing is often used to qualify area array packages (e.g. Ball Grid Arrays and Flip Chip) for various applications. Finite element life predictions for thermal cycling configurations are challenging due to the complicated temperature/time dependent constitutive relations and failure criteria needed for solders and encapsulants and their interfaces, aging/evolving...
In this paper the potential of molecular dynamics simulation for structure-property correlations in epoxy-resins is discussed. This is a topic relevant for a multi-scale framework to lifetime prediction in microelectronics packaging. To achieve that objective, epoxy-resins are synthesised by systematically varying their chemical structure and then characterised by various thermo-mechanical testing...
The thermomechanical fatigue of solder joints on the system level is more complex to predict than on the board level. The damage of the solder joints of an electronic device in an ECU (electronic control unit) depends on the thermal expansion mismatch between the materials of the device and the PCB (printed circuit board), so called local mismatch, as well as on the global deformation of the PCB induced...
Interfacial adhesion between the Epoxy Molding Compound (EMC) and the copper-based leadframe is one of the major concerns in the qualification of plastic packages. Since the conventional shear testing methods used in industry do not consider the residual stresses in the shear samples, they are only used as a qualitative testing method for the EMC qualifications. However, since these tests are based...
A set of experimental and computer simulation methods has been applied to reliability analysis of a newly designed resin transfer molded power electronics module for automotive applications, comprising the glass-fiber epoxy multi-layer PCB, populated with various electronic packages. Evaluation of thermo-mechanical stability, determination of moisture ingress, and testing the adhesion quality between...
It is well known that high temperature storage can degrade wire bonding contacts significantly due to interdiffusion of pad metal and bonding wire. Looking at harsh applications such as engine management we notice an additional failure mode caused by the temperature gradient during the pulsed active cycling period. Especially when we aim at components with high temperature capability and we substitute...
The numerical pre-design of a novel micro-machined thermal infrared emitter, using a spider type hotplate concept is presented. The spider concept introduced allows the fast transient operation of the emitter and thus a direct modulation of the radiation without additional mechanical tools like choppers. The thermal radiation source is excited by a pulsed electrical voltage and is thermally separated...
The components used in the automotive environment are subjected during their lives to various environmental combined stresses. The predominant failure mechanism at the package level due to these combined stresses is the ball bond lift. The failure is due to the combination of metallurgical effects, such as the intermetallic (IMC) Au-Al thickness growth, widening of Kirkendall voids and mechanical...
In this paper, a framework for fusion approach to IGBT power module prognostics is reported. A failure modes, mechanisms, and effects analysis (FMMEA) for the IGBT power module is performed to identify critical failure mechanisms. For the failure mechanisms identified, relevant physics of failure models are discussed. In addition, the parameters affected by the critical failure mechanisms are identified...
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...
The aerospace and high performance (AHP) electronics industry leans henceforth on the technologies developed for consumer applications. However, the requirements of AHP products in terms of reliability are stronger than for consumer ones. One of the factors to improve the reliability in thermal cycling of electronic assemblies is the selection of base materials for Printed Circuit Boards (PCB). In...
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...
The paper presents extended creep properties of eutectic SnAg3.8Cu0.7 solder using dog bone shaped tensile specimen to extend the data for the Alpha-Omega Model. The tensile test machine was carefully modified with respect of solder material requirements in terms of stress free specimen mounting and assurances of high stable stress conditions. Furthermore the tensile tester is able to measure the...
The use of temperature and time dependent material parameters is state-of-the-art in mechanical engineering. An advanced measurement method for the determination of moisture dependent parameters for micro and nano scale samples was developed. In combination with FE-analysis, this tool (involving time, temperature, and humidity) ensures a sure deployability. The present paper deals with the influence...
The paper focuses on influence of materials properties and molding processes parameters on warpage of bimaterial silicon-molding compound (MC) systems. The three different MCs of different glass transition temperature Tg and different coefficients of thermal expansion (CTE) were considered in numerical and experimental investigation. The post molding processes and their influence on warpage were analyzed...
An enhanced smart flow sensor is being developed at IMTEK in order to measure both flow and thermal properties of fluids at the same time. To be able to measure the thermal properties of a fluid, a sinusoidal voltage is applied at heater. This results in a time-dependent temperature response on a thermistor array. Amplitudes of the temperature signals on the thermistors, and thus the maximum sensitivity...
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