2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)最新文献

{"title":"Simulations for nanoindentation on thin metal films and the potential influence of creep","authors":"N. Jöhrmann, R. Ecke, B. Wunderle","doi":"10.1109/EuroSimE52062.2021.9410851","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410851","url":null,"abstract":"Thin metal films have been present in microelectronic packaging for a long time as e.g. RDL and BEOL structures, terminal metal or shielding layers. In most use cases, thin metal layers will be thermo-mechanically loaded, leading e.g. to disruption due to high thermal transients, or to fatigue cracks due to periodic sub-critical bending, thus causing reliability problems. In order to understand, describe and model the underlying failure mechanisms within a physics-of-failure approach, it is important to characterize thin metal films for their thermo-mechanical properties. It is known, that thin metals are highly process dependent in their properties. Also, the small thickness introduces size effects, so methods requiring thick or bulk samples are not of much use. This paper discusses the applicability and challenges of combining nanoindentation (NI) on thin metal films with FE simulations to obtain material properties. To that end, nanoindentation and atomic force microscopy (AFM) measurements on Ni, Cu, and Al are investigated together with finite element simulations to obtain elastic-plastic material properties. As there are some differences observed between experimental and simulated loading curves, the potential influence of creep on the simulation results is considered.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114887534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the mechanical behavior of a Printed Circuit Board (PCB)","authors":"A. Atintoh, W. Kpobie, N. Bonfoh, M. Fendler, F. Addiego, P. Lipinski","doi":"10.1109/EuroSimE52062.2021.9410852","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410852","url":null,"abstract":"The present study deals with a characterization of the anisotropic mechanical behavior of Printed Circuit Board (PCB) through an inverse method combining experiments and numerical simulations. The considered PCB is a woven laminate composite that consists of glass fiber reinforced epoxy matrix (FR4) and copper traces. Prior to numerical simulations, some simple mechanical tests were conducted in order to characterize the mechanical behavior of layers of FR4 and the corresponding PCB. Then, through a multiscale homogenization approach, unknown elastic properties of the PCB have been estimated by comparison with experimental results. This numerical homogenization was performed by the means of the Mechanics of Structure Genome (MSG) methodology. The main advantage of this MSG-based model is its ability to simultaneously estimate all the independent components of the tensor of elastic constants through only one computation, with a relatively low CPU time.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116380279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Bragg Acoustic Reflector on Thermal Processes in SMR under High Power Levels","authors":"A. Kozlov","doi":"10.1109/EuroSimE52062.2021.9410835","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410835","url":null,"abstract":"The paper discusses the thermal processes in solidly mounted resonators with various types of a Bragg acoustic reflector. For modeling temperature distribution in the structure of the resonator, the 2D analytical model is used. The structure of the resonator is divided into seven regions. The region of the Bragg acoustic reflector is substituted by equivalent structure for which the equivalent thickness and thermal conductivity are determined. The parameters of other regions correspond directly to the ones of the resonator layers. For all regions, the stationary heat conduction equation and the corresponding boundary conditions are established. The solution of the heat equation is carried out by analytical method. Using this approach the overheating temperature distributions in the solidly mounted resonators consisting of a thin-film piezoelectric transducer based on AlN or ZnO layer and Bragg acoustic reflector based on 5 pair of Al-Mo or SiO2-Mo layers, were determined. Also the dependencies of the specific power generated in piezoelectric layer and the weighted average overheating temperature of this layer in the resonators with the various reflectors on the resonance frequency were found.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126572383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Analysis of Microfluidic cooling in Processing-in-3D-Stacked Memory","authors":"Jun-Han Han, Karina Torres‐Castro, R. West, N. Swami, M. Stan","doi":"10.1109/EuroSimE52062.2021.9410836","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410836","url":null,"abstract":"Recent 3D-stacked Processing-In-Memory (PIM) research investigates improved performance by transferring computation from the CPU into memory. Although PIM’s integration in 3D-stacked memory can achieve better performance, it leads to higher power density than conventional memory operations. The increased power density causes 3D-stacked memory to exacerbate thermal issues. Traditional heat sink cooling on the top surface generates a mismatch between the 3D volumetric heat flux generation and a surface cooling capacity. In this study, we demonstrate a microfluidic cooling technique for PIM in 3D stacked memories. Our technique exploits gaps between the memory die and the gap between the logic die and interposer as cooling chambers. We model the thermal and fluidic characteristics of 3D stacked memory simultaneously. A 64 mm2 of memory, consuming 64W for PIM operation, can be cooled under 85 with a 16.5 ml/min rate of coolant flow. We also performed 2D and 3D COMSOL simulations of the thermal behavior and microfluidic cooling for die-stacked memories operating with PIM.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"74 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131451225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topology Optimization of Miniaturized Piezoelectric Energy Harvester","authors":"Siyang Hu, Ulrike Fitzer, T. Bechtold","doi":"10.1109/EuroSimE52062.2021.9410873","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410873","url":null,"abstract":"In this contribution, we perform topology optimization on the mechanical structure of the multi-resonant folded beam energy harvester. The optimization goal is to minimize the spacing between its first two resonance frequencies and create a wider usable frequency range for energy harvesting. Two different optimizations have been performed. First optimization has successfully reduced the spacing to 2 Hz. For the second optimization, we excluded rectangular surface areas from the optimization, dedicated for commercial piezoelectric patches. The additional constraint has led to a larger frequency spacing compared to the initial optimization, 7 Hz, however this result is still a significant improvement over the starting geometry. Piezoelectricity model and comparison with existing parameter optimized designs will be included in the upcoming publication.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127574936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Anisotropic Viscoplasticity on SAC305 Solder Joint Deformation: Grain-scale Modeling of Temperature Cycling","authors":"Q. Jiang, A. Deshpande, A. Dasgupta","doi":"10.1109/EuroSimE52062.2021.9410845","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410845","url":null,"abstract":"The piece-to-piece variation among Sn-based lead-free solder joints is commonly attributed to stochastic variations in grain structure and the anisotropy inherent in the body-centered tetragonal (BCT) y#-Sn lattice structure, especially for micron-scale joints that contain only a few grains. Parametric simulations of different microstructures, using grain-scale modeling, offer a convenient approach to estimate the degree of variability. Thus, although it is impossible to accurately predict the response of a given joint without knowing the microstructure, the best-case and worst-case limits of its behavior can be estimated. A crystal viscoplasticity approach has been developed to describe the anisotropic steady-state creep behavior of SAC single crystals and calibrated with results from literature and with in-house testing. The overall response of a single crystal has been characterized by a corresponding homogenized continuum-scale creep model based on Hill’s anisotropic potential, in conjunction with Norton power-law model for creep rates. In this study, the Hill-Norton model described above is applied to analyze the effect of grain orientation on the viscoplastic response and durability of a singlecrystal solder joint under the combined action of compressive and thermal cyclic loading. The predicted lifetime, based on volume-averaged creep dissipation energy density, shows 31% variation for best-case and worst-case grain orientations.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"207 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131258333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating Local Delamination of Power Electronic Devices Through Thermal-Mechanical Analysis","authors":"H. Huai, G. Laskin, M. Fratz, T. Seyler, T. Beckmann, A. Bertz, D. Carl, J. Wilde","doi":"10.1109/EuroSimE52062.2021.9410840","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410840","url":null,"abstract":"In this study, the effect of die attachment delamination on deformation of power devices during passive heating is investigated. For this purpose, Insulated Gate Bipolar Transistors (IGBT) are silver sintered with defects in their die-attachment on Printed Circuit Board (PCB) substrates. The passive heating process takes place on a hotplate under isothermal loading conditions between $50^{circ}mathrm{C}$ and $200^{circ}mathrm{C}$ while the deformation is measured optically using Digital Image Correlation (DIC) and Electronic Speckle Pattern Interferometry (ESPI). At the same time, a finite element simulation model is created with the same defect geometries and is tested for similar thermal conditions. By comparing simulation and measurement results it can be concluded that a simulative approach can deliver reliable data concerning local delamination defects. Those established methods can then be used during the quality check of devices. Optical methods will be used to filter out faulty specimens through their behavior in thermal deformation, which will be referring to the results of prior simulations.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"231 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132435235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modified Norris-Landzberg Model for Reliability of Pb-free BGA Components","authors":"W. Xie","doi":"10.1109/EuroSimE52062.2021.9410871","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410871","url":null,"abstract":"One important task for reliability engineers in new product design phase is to evaluate the long-term reliability of Pb-free solder joints under the service environment conditions. It is a common practice, due to the practical restrictions such as cost and aggressive development cycle time, to map the results under accelerated testing conditions to field conditions via well-benchmarked transform models. One of the most widely adopted models is the modified version based on Norris-Landzberg (NL) Acceleration Factor (AF) model [1]. The popular NL AF model simultaneously makes it easy to apply but difficult to correlate with data from different sources. In fact, there is ongoing discussion that questions the validity of the model [2]. To overcome the shortcomings of the model, Salmela [3] has suggested a correction term to consider package type and solder material along with the temperature and the dwell time on the solder joint. Chuang, et al. [4] have compared several models and confirmed that the prediction based on Salmela’s model is closer to their testing results. Ahmad, et al. [5] have proposed the constants of NL AF model as functions of the characteristic life under the accelerated testing conditions. All of those aforementioned variations of NL AF models, while improving the model prediction, would still need different constants for data under different situations; therefore, it is not convenient to use especially in product design phase where some critical information such as the package detail and testing results may not be available.In this paper, a unified NL AF model has been proposed by introducing an add-in impact function to factor package-related contributors such as package size, die size, joint pitch, and delta CTE. It is demonstrated that such an impact function enables NL AF model to correlate very well with a wide range of experimental data using one unified set of constants that were derived by nonlinear fitting of 112 data points from internal source and public domain publications. The robustness of the derived constants was then validated using the generic algorithm to ensure the best of the goodness-of-fit while minimizing the standard residual error. The resulting model has $mathrm{R}^{2}$ equals 0.845 which showed a good correlation with the testing results. Furthermore, the derived model has been benchmarked with the testing results of iNEMI Pb-free solder alloy alternative project ([6]–[9]), an in-depth industry wide collaboration. The testing results are representable as two types of components with different solder alloys have been tested under multiple temperature cycling profiles. The benchmarking demonstrates a really good correlation as the majority of the predicted life, from the derived model, fall into + /-50% band compared with the testing results. Hence the proposed NL AF model, with a unified constant set, can be very helpful and handy in product design phase for reliability assessment.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129130131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Test Screening of Solder Joints Under Combined Cyclic Thermal and Bending Load for Automotive Applications","authors":"J. Gleichauf, Y. Maniar, S. Wiese","doi":"10.1109/EuroSimE52062.2021.9410829","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410829","url":null,"abstract":"The cost and time efficient qualification process of solder joints’ reliability in automotive electronic assemblies requires accelerated temperature cycling (ATC) testing. This work introduces a load-dependent reliability assessment method on board level for solder joints of multilayer ceramic capacitors (MLCC) under superimposed cyclic thermal and 3-point bending load. For this purpose, a testing setup is developed, which enables statistical testing of solder connections under accelerated load scenarios. The solder joints are monitored online by means of impedance measurement until failure. In this work, solder joint failure of a large amount of MLCC 1206 components is experimentally investigated, where the following lifetime influencing factors are studied: solder volume variation and MLCC 1206 components from different suppliers.The resulting lifetime of solder joints with volume variation reveals, that under the same loading conditions smaller solder joints show a significantly lower survival probability compared to solder joints with larger volumes. Furthermore, significant differences in solder joint lifetime between components from the two different suppliers are observed.In order to derive a load-dependent failure criterion using measurement data, finite element (FE) simulation is performed under consideration of test boundary conditions. In this way, printed circuit board (PCB) deformation is determined, taking into account both the thermal and mechanical induced strains. It is shown, that the relationship between calculated load-dependent PCB strain amplitudes and experimentally detected solder joint failures are described by a power law leading to component Woehler curves for different failure probabilities.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126729059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Improvement of the Life Time Performance Estimation for Interconnect Stacks in Realistic Layouts","authors":"V. Hein, K. Weide-Zaage","doi":"10.1109/EuroSimE52062.2021.9410880","DOIUrl":"https://doi.org/10.1109/EuroSimE52062.2021.9410880","url":null,"abstract":"The experimental determination of the intrinsic life time of a metallization stack is determined by the used test structures of metal lines and via-metal test structures. The test structure layout is prepared according to the presumption of the failure mechanisms modelled by Black’s Law. The interconnect reliability test structures are optimized. They have metal tracks which exceed the Blech length and contain dummy lines in a minimal spacing distance to the test line. Interconnects in realistic circuit layouts are different. They contain metal tracks and via connections with different surroundings like neighbour lines and a different density in metal, inter-metal- dielectric and via number. The sum of the overall mass flux divergence of the interconnects which determines the local mass transport and the life time are not only predicted by the current density and temperature. The distribution of mechanical stress influences mass transport as well. The local changes in mechanical stress like stress in chip corners, circuits under pad and via stacks up to thick metal top layers are not considered in the life time calculation based on Black’s Law. The mass flux simulation is a powerful tool to detect critical areas and the reliability of the outcome of process and layout optimizations. But the effort for such simulations is quite high and limited for some exemplary tasks. The paper shows the use of the multiple regression approach with moderation and mediation models. The models allow to detect indirect effects because of existing mediator variables or interactions with potential moderators. The derived models and regression coefficients can be used for more accurate life time predictions, for a reduced simulation effort and investigations on realistic interconnect stacks.","PeriodicalId":198782,"journal":{"name":"2021 22nd International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131219950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}