Virtual thermo-mechanical prototyping of microelectronics devices

Microelectronics have pervaded our lives for the past fifty years, with massive penetration into health, mobility, safety and security, communications, education, entertainment and virtually every aspect of human lives. The main technology drivers that enabled this expansion are miniaturization and integration. The combination of these two has driven microelectronics technology into an unknown level of complexity and as a consequence, we are confronted with increasing difficulties to meet quality, robustness and reliability requirements. In this thesis, a general virtual thermo-mechanical prototyping framework is developed that is able to predict the non-linear responses in microelectronics devices prior to physical prototyping and/or reliability testing. The uniqueness of the developed framework relies, for the first time, on the following three aspects: · The development of advanced simulation-based optimisation algorithms and methods, being Design Of Experiments (DOE) and Response Surface Models (RSM). · The development of accurate and efficient thermo-mechanical prediction models able to capture the damage responses within microelectronics devices during manufacturing and reliability qualification tests. · To seamlessly and efficiently integrate the prediction models with the optimisation algorithms. The developed framework is applied to four case studies of reliability topics in microelectronics devices. The results of these four case studies correlate well with experiments and/or field returns and prove the predictability of the developed techniques.Mechanical Maritime and Materials Engineerin

LED degradation: From component to system

Human civilization revolves around artificial light. Since its earliest incarnation as firelight to its most recent as electric light, artificial light is at the core of our existence. It has freed us from the temporal and spatial constraints of daylight by allowing us to function equally well night and day, indoors and outdoors. It evolved from open fire, candles, carbon arc lamp, incandescent lamp, fluorescent lamp to what is now on our door step: solid state lighting (SSL). SSL refers to a type of lighting that uses semiconductor light-emitting diodes (LEDs), organic or polymer light-emitting diodes (OLED/PLED) as sources of illumination rather than electrical filaments, plasma (used in arc lamps such as fluorescent lamps), or gas. SSL applications are now at the doorstep of massive market entry into our offices and homes. This penetration is mainly due to the promise of an increased reliability with an energy saving opportunity: a low cost reliable solution. An SSL system is composed of a LED engine with a micro-electronics driver(s), integrated in a housing that also provides the optical, sensing and other functions. Knowledge of (system) reliability is crucial for not only the business success of the future SSL applications, but also solving many associated scientific challenges. In practice, a malfunction of the system might be induced by the failure and/or degradation of the subsystems/interfaces. This paper will address the items to ensure high reliability of SSL systems by describing LED degradation from a component and a system perspective

Orthodontic treatment: Introducing finite element analysis

The aim of orthodontic treatment is the displacement of teeth by means ofspecial appliances, like braces and brackets. Through these appliances the orthodontist can apply a set of forces to the teeth which wilt result in its displacement through the jawbone. Finite Element analysis of this process enables to comprehend the influence of the applied forces and its transmission to the surrounding tissues. Using appropriate material models enlarges the success of the analysis. As a first step to elucidate the effects of orthodontic treatment, our objective is to find such an appropriate material model for the biologica! tissues invo/ved. Therefore, we performed a series of experiments and analyzed theet within a framework of Finite Element model