1,720,990 research outputs found
Design for Reliability of Wafer Level MEMS packaging
No full textThe world has seen an unrivaled spread of semiconductor technology into virtually any part of society. The main enablers of this semiconductor rush are the decreasing feature size and the constantly decreasing costs of semiconductors. The decreasing costs of semiconductors in general are caused by the smaller feature size, the higher yield and larger production volumes. This has made products containing semiconductors cheaper in production thus reaching a larger market. The smaller feature size enables more computing power in the same volume creating new markets and growing application areas. The increasing number of appliances using semiconductor components is also driving the fast growth of the market. The trend of miniaturization of electronic components also demands the miniaturization and integration of non-electrical functions to allow for large decreases in size, weight and possibly cost. Soon after the first semiconductors were developed the first Micro Electrical Mechanical Systems (MEMS) were also created. In the 1960’s and 1970’s experiments with MEMS were done in lab environments. MEMS technology can be used to miniaturize non-electrical components thus enabling further system shrinkage and increased function density. The technologies, experiments and numerical simulations in this thesis provide MEMS designers with a design guideline in the creation process of new Wafer Level Thin Film Package (WLTFP) products as well as an overview of the most likely failure modes and high risk processes in the assembly. WLTFP’s are a miniature batch-process and wafer scale encapsulation method for MEMS that need space to move or hold a certain amount of gas. In the first chapters an overview of the most important processing steps in the production of WLTFP’s and the subsequent assembly steps needed to form a plastic encapsulated package is presented. Most common assembly steps included: wafer thinning, chip singulation, die-attach, wire bonding, overmoulding and saw, trim, mark & form. Wafer thinning is necessary to thin the chip to such a thickness that it will fit into the desired package. Chip singulation or dicing is commonly done by a diamond blade saw and makes separates the wafer into individual chips. Die-attach is the placement of the chip onto the carrier, for example a lead frame, by means of a glue. After dieattach connection the IO of the chip to the carrier can be done by wirebonding. After wire-bonding the package is overflowed by epoxy moulding compound to protect the chip inside from the environment. After finishing the package and marking it one has a complete product. In the creation process of a new MEMS product the design team is faced with a multi-scale, multi-physics and multi-timescale challenge. Nanometer dimensions can impact a millimeter size product and hours of operation can change a MEMS that performs microsecond measurements. To address this challenge an integrated design process is needed that covers the chip and wafer design as well as the package and all of the intermediate processes. An example of the influences from the package on the chip is calculated and shown in chapter three. In chapter four the properties of thin layers are investigated. In this investigation copper thin film are deposited on freestanding micro cantilevers. The samples are analyzed with white light interferometry to obtain the initial geometry properties and cantilever warpage. Using electrostatic pull-in to pull down the cantilever to the substrate the pull-in voltage is obtained. The stiffness of the two layer system can be derived from the pull-in voltage. Copper film thicknesses of 10 and 50 nanometer are measured and a size-dependant stiffness is proven. During the assembly of a WLTFP several failure modes are found. In the wafer thinning process the application of wafer thinning tape to the active side of the wafer can easily break many WLTFP’s. This can happen during the application or for example the removal of the tape. The placement of the wafer on dicing foil is also a potential risk as it leaves the MEMS exposed to the water jet of the dicing machine. Wire-bonding can be hazardous to MEMS sensitive to resonance, this risk can relatively easy be mitigated by calculation of eigenmodes and eigenfrequencies. The overmoulding process and the associated process pressure can be hazardous to for example membranes or large WLTFP’s due to the static pressure on the cavity. The numerical simulations developed in chapter five provide a toolbox to check for weak spots in the design and investigate changes by virtual prototyping instead of physical prototyping. The simulations also include wafer foil application and removal simulation. The use of cohesive zones allows for a detailed investigation of the loads on the WLTFP. In chapter six the interface properties of the wafer thinning foil are investigated by means of a peeling experiment combined with numerical simulations. The characterization method yields interface properties that serve as input for aforementioned numerical simulations. The Design of Experiments presented in chapter seven investigates the influence four major design choices on the likelihood of survival during assembly. The span of the WLTFP, the corner rounding radius, cap thickness and presence of a pillar are investigated. After all 18720 samples were evaluated a design guidelines was derived. The design guideline in combination with the numerical simulations provides the MEMS design community with tools during the chip-design stage. This aids to the integrated approach of designing new MEMS and reduces the time to market and number of design iterations needed.PMEMechanical, Maritime and Materials Engineerin
Reliability of Organic Compounds in Microelectronics and Optoelectronics: From Physics-of-Failure to Physics-of-Degradation
No full textThis book aims to provide a comprehensive reference into the critical subject of failure and degradation in organic materials, used in optoelectronics and microelectronics systems and devices. Readers in different industrial sectors, including microelectronics, automotive, lighting, oil/gas, and petrochemical will benefit from this book. Several case studies and examples are discussed, which readers will find useful to assess and mitigate similar failure cases. More importantly, this book presents methodologies and useful approaches in analyzing a failure and in relating a failure to the reliability of materials and systems.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
A Design for Six Sigma based predevelopment processes: Facilitated by a Product Lifecycle Management System
No full textThis thesis proposes a process including deliverables based on Design for Six Sgima to be used in predevelopment which is supported by a Product Lifecycle Management System.Information ArchitectureComputer ScienceElectrical Engineering, Mathematics and Computer Scienc
Virtual thermo-mechanical prototyping of microelectronics devices
No full textMicroelectronics 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-Based Luminaire Color Shift Acceleration and Prediction
No full textColor stability is of major concern for LED-based products. Currently, much effort is done on lumen maintenance, and for color shift, no agreed method currently exists, be it from testing or from prediction side. To investigate the physics of color shift, we present experiments of each individual part failure of each individual part that are present in LED-based products. In order to develop a color shift prediction method, it is imperative to investigate the color shift contribution by each individual part. We present a new method to predict color shift on a system level, which we named the view factor approach. We compare this prediction method with experiments on luminaire level to conclude that we have taken satisfactory first steps in the field of color shift predictions for LED-based systems.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Statistical Analysis of Lumen Depreciation for LED Packages
No full textCommercial claims for LED-based products in terms of lumen maintenance are fully based on TM-21 extrapolations using LM-80 data. This chapter indicates that there may be a risk in doing this as TM-21 only relies on the behavior of the average LED degradation, instead of taking into account the degradation of all individual LEDs. Therefore, we propose a more profound statistical approach in order to make the appropriate step from TM-21 extrapolation to lumen maintenance on a product level. This is needed as some commercial claims are based on 10 years of warranty and some service bids provide periods of 20–25 years of operation. This chapter reviews the different approaches currently available to perform lumen maintenance extrapolations.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
The Next Frontier: Reliability of Complex Systems
No full textTraditional lighting is focused on the prevention of hardware failures. With the trend toward controlled and connected systems, other components will start playing an equal role in the reliability of it. Here reliability need to be replaced by availability, and other modeling approaches are to be taken into account. Software reliability can only be covered by growth models, with the Goel-Okumoto as a promising candidate. System prognostics and health management is the next step to service the connected complex systems in the most effective way possible. In this chapter we highlight the next frontiers that will need to be taken in order to move the traditional lighting catastrophic failure thinking into a thinking more toward new ways how system (degraded) functions can fail or be compromised.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Corrosion Sensitivity of LED Packages
No full textThe penetration of solid state lighting applications is due to the promise of a low-cost reliable solution by means of application of low- and mid-power LEDs. These LED packages are manufactured by making use of new processes and materials which in principle introduces a series of known and unknown failure modes. Corrosion is a specific failure mode which limits the lifetime, and hence manufacturers realize that their package integrity needs to be improved. This chapter describes the sensitivity to corrosion of LED packages. In the first part, an introduction to chemical incompatibility is given. In the second part, different sources of corrosion are distinguished. The construction of LED packages and their vulnerability to corrosion is described in the third part. In the fourth part of this chapter, testing methods are reviewed and their effectiveness to simulate real-life conditions. A series of experimental setups is used to explore the behavior of LED packages in contaminated environments. A combined experimental–theoretical approach is used to describe the performance in certain conditions of pollution. This will be covered in the fifth part. The last part describes a list of classes of chemicals, often found in electronics and construction materials for luminaires that may affect LED performance and for this reason should be avoided for the design of SSL solutions.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Special issue: International conference on thermal, mechanical & multiphysics simulation and experiments in micro- and nano-electronics and systems [EuroSimE2017]
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Optical degradation mechanisms and accelerated reliability evaluation for LEDs
No full textElectronic Components, Technology and Material
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