INCOBAT: Innovative Cost Efficient Management System for Next Generation High Voltage Batteries

Electro-mobility is considered as a key technology to achieve green mobility and fulfil tomorrow’s emission standards. However, different challenges still need to be faced to achieve comparable performances to conventional vehicles and finally obtain market acceptance. Two of these challenges are vehicle range and production costs. In that context, the aim of the INCOBAT project (October 2013 – December 2016) was to provide innovative and cost efficient battery management systems for next generation HV-batteries. INCOBAT presents a platform concept that achieves cost reduction, reduced complexity, increased reliability and flexibility while at the same time reaching higher energy efficiency. Advantages of this approach include: Tight control of the cell function leading to a significant increase of the driving range of the FEV; Radical cost reduction of the battery management system with respect to current solutions; Development of modular concepts for system architecture and partitioning, safety, security, reliability as well as verification and validation, thus enabling efficient integration into different vehicle platforms. The INCOBAT project focused on the following twelve technical innovations grouped into four innovation groups, which are summarized in this book: Customer needs and integration aspects Transversal innovation Technology innovatio

An improved micromechanical method for investigating the mechanical properties of poly-silicon membranes

Freestanding poly-silicon membranes are of increasing importance for designing MEMS devices such as pressure sensors, microphones and gyroscopes. It is crucial to accurately determine the mechanical properties of such membranes not only to access parameters for designing new devices but also for assuring proper performance and quality in service. Classically, microscopic tensile tests [1-3] or bulge tests [4] were conducted to obtain Young’s modulus and strength of the membrane material. These methods however are prone to artifacts due to crack initiation at edge defects (e.g. predefined notches in tensile specimens [3] or slits in bulge test samples [4]). In search of a method more sensitive to the membrane surface rather than specimen geometries, a novel approach has been introduced more recently. By loading the center region of a circumferentially clamped membrane with a spherical probe, the membrane is stretched all the way up to rupture while precisely recording the load-deflection data. Complementary FEA simulations allow for determining the failure stresses of individual membranes, based on the mechanical test data. In a subsequent step the tests are analyzed via a two-parameter Weibull approach to statistically evaluate the characteristic fracture strength. The membranes tested in the given project had a thickness of only 330 nm over a diameter of 1 mm. The necessity to apply minute forces while testing the compliant membranes at quite large deflections with high precision proves to be challenging. Additionally the need for statistical verification requires conducting multiple tests in a reasonable time frame. In the presented work a commercial nanoindenter has been used to match the aforementioned requirements. Lately some methodological improvements have been implemented to maximize throughput by automation and improve accuracy by refining the data analysis to capture the experimental conditions most realistically. Some of these approaches will be illustrated by recent data and explained in detail

On the Feasibility of Fan-Out Wafer-Level Packaging of Capacitive Micromachined Ultrasound Transducers (CMUT) by Using Inkjet-Printed Redistribution Layers

Fan-out wafer-level packaging (FOWLP) is an interesting platform for Microelectromechanical systems (MEMS) sensor packaging. Employing FOWLP for MEMS sensor packaging has some unique challenges, while some originate merely from the fabrication of redistribution layers (RDL). For instance, it is crucial to protect the delicate structures and fragile membranes during RDL formation. Thus, additive manufacturing (AM) for RDL formation seems to be an auspicious approach, as those challenges are conquered by principle. In this study, by exploiting the benefits of AM, RDLs for fan-out packaging of capacitive micromachined ultrasound transducers (CMUT) were realized via drop-on-demand inkjet printing technology. The long-term reliability of the printed tracks was assessed via temperature cycling tests. The effects of multilayering and implementation of an insulating ramp on the reliability of the conductive tracks were identified. Packaging-induced stresses on CMUT dies were further investigated via laser-Doppler vibrometry (LDV) measurements and the corresponding resonance frequency shift. Conclusively, the bottlenecks of the inkjet-printed RDLs for FOWLP were discussed in detail.EC/H2020/737487/EU/(Ultra)Sound Interfaces and Low Energy iNtegrated SEnsors/SILENS

AI at the Edge, 2021 EPoSS White Paper

In this paper members of the European Platform on Smart Systems Integration (EPoSS) have collected their views on the benefits of incorporating Artificial Intelligence in future Smart devices and defined the actions required to achieve this to implement "AI at the Edge"

DNA mismatch repair gene MSH6 implicated in determining age at natural menopause

notes: PMCID: PMC3976329This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.The length of female reproductive lifespan is associated with multiple adverse outcomes, including breast cancer, cardiovascular disease and infertility. The biological processes that govern the timing of the beginning and end of reproductive life are not well understood. Genetic variants are known to contribute to ∼50% of the variation in both age at menarche and menopause, but to date the known genes explain <15% of the genetic component. We have used genome-wide association in a bivariate meta-analysis of both traits to identify genes involved in determining reproductive lifespan. We observed significant genetic correlation between the two traits using genome-wide complex trait analysis. However, we found no robust statistical evidence for individual variants with an effect on both traits. A novel association with age at menopause was detected for a variant rs1800932 in the mismatch repair gene MSH6 (P = 1.9 × 10(-9)), which was also associated with altered expression levels of MSH6 mRNA in multiple tissues. This study contributes to the growing evidence that DNA repair processes play a key role in ovarian ageing and could be an important therapeutic target for infertility.UK Medical Research CouncilWellcome Trus

Automated virtual prototyping for fastest time-to-market of new system in package solutions

A modular system of parametric FE models is created using ANSYS parametric design language (APDL) for automated virtual prototyping of current and future System-inPackage (SiP) solutions based on fan-out-wafer-level-packaging (FOWLP) technologies. The principles of the hierarchical architecture are described and instructive examples are given for all levels, i.e., from the part models to the four demonstrator packages. Further, the results of first simulations addressing the typical load case of temperature cycling between - 40 °C and 125 °C clearly demonstrate the validity of the approach as they agree to the experimental finding. The system of models is now applicable to a large variety of future SiP products based on FOWLP. It will allow virtual prototyping, i.e., replace time consuming experimental tests during the product definition phase

Assessment of FOWLP process dependent wafer warpage using parametric FE study

The paper presents the steps for the parametric finite element model creation of the wafer, material characterization of the adhesive tape, analytical and finite element study of the wafer warpage considering the bifurcation, gravity effect on the wafer bow assessing the warpage of mold/Si bilayered structure under thermal loading. The analytical results are compared to finite element analyses (FEA) considering the linear and nonlinear deflection. Consequently, the FEA approach has been used to study the deformation of 12” reconstituted wafers in their FOWLP fabrication process. By changing the temperature, the deformation of the wafer shows a bifurcation point, at which the warpage changes between the spherical and cylindrical shapes. The bifurcation region has been analyzed for the relevant range of overmold thicknesses in order to provide the guidance to optimum wafer and process designs that avoid the excessive warpage. For different wafer structures, the study determines also the effects of the gravitational force on the wafer bow as well as its influence in combination with the thermal mismatch. Finally, the FOWLP process induced warpage has been demonstrated by FEA incorporating the geometrical nonlinearity, gravity and ground support by means of contact elements

FEA to Tackle Damage and Cracking Risks in BEoL Structures under Copper Wire Bonding Impact

With the recent increase in Gold (Au) wire cost Copper (Cu) wire becomes an attractive way to manage overall package cost. On the other hand, Copper wire bonding introduces much higher mechanical impact to underlying BEoL structures and actives because of the higher stiffness and lower ductility of Copper compared to Gold. These trends are accompanied by the application of new porous or nano-particle filled materials like low-k and ultra low-k materials for Back-end of Line (BEoL) layers of advanced CMOS technologies. As a result, higher delamination and cracking risks in BEoL structures underneath bonded areas represent an increasing challenge for the thermo-mechanical reliability requirements. To overcome the related reliability issues the authors performed a two level nonlinear FEM-simulation approach. Initially nonlinear axi-symmetric modeling and simulation of the copper bonding process are coupled with a spatial simulation model of the whole BeoL and bond pad structure. Cracking and delamination risks are estimated by a surface based cohesive contact approach and the utilization of a crushing foam constitutive material model for ultra low-k materials