2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems最新文献

{"title":"Modelling of the Electric Field Assisted Capillarity Effect used for the fabrication of hollow polymer microstructures","authors":"C. Tonry, M. Patel, C. Bailey, M. Desmuliez, S. Cargill, W. Yu","doi":"10.1109/ESIME.2012.6191758","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191758","url":null,"abstract":"Electric Field Assisted Capillarity (EFAC) is a novel process which has the potential for the single step fabrication of hollow polymer microstructures. The process has been shown to work experimentally on a microscale level using Polydimethylsiloxane (PDMS). The process makes use of both the electrohydrodynamics of polymer at a microscale and the voltage enhanced capillary force exerted on the polymer. This paper discusses the results of a two-dimensional numerical simulation of this process. The results presented use a patterned master electrode producing encapsulated microchannels in the polymer. The simulations demonstrate how the differing contact angles between the polymer and the walls of the master electrode affect the thickness of the top surface of the formed microstructures. It also specifies the conditions necessary for the successful fabrication of such microstructures.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121552225","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":"Viscoplastic behavior of diamond die attach subjected to high temperature conditions","authors":"S. Msolli, A. Baazaoui, O. Dalverny, J. Alexis, M. Karama","doi":"10.1109/ESIME.2012.6191747","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191747","url":null,"abstract":"In power electronic applications, diamond based semi-conductors appears to be a new way to widely increase the capabilities of power electronic converters. The main prospective expected is an increasing in system integration and power capabilities. The Diamonix project concerns the elaboration of a single-crystal diamond substrate with electronic quality and its associated packaging. The designed structure has to resist to temperatures varying between -50°C and +300°C. This paper deals with an experimental and numerical study of the diamond die attach solution. The development of a packaging for diamond component relies in particular on a specific choice of solder's alloys for the junction die/substrate. To carry out this junction, AuGe and AlSi eutectic alloys were chosen and characterized; the choice of these two kinds of solders i.e. AuGe and AlSi is motivated by the practical elaboration process and the restrictions of hazardous substances (RoHS). The first solder has a melting temperature of 356°C; the second has a higher melting point of 577°C. In this paper, we present some numerical results obtained from FE simulations of two 2D configurations of simplified electronic packaging. The power electronic packaging is composed of a diamond die and a copper metallized Si3N4 ceramic substrate which are brazed together with either AuGe or AlSi solder alloy. To predict the thermomechanical behavior of the solders, a particular constitutive behavior law was implemented as a User MATerial subroutine which is based on a viscoplastic unified McDowell formulation, coupled with porous damage equations. The mechanical law can describe precisely the viscoplastic damage phenomenon of solder subjected to high thermal cycling and to optimize the thermo-mechanical modeling for advanced package development.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122319124","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":"Interfacial fracture toughness measurements in microelectronic packages with different test setups on samples from production","authors":"I. Maus, H. Pape, H. Nabi, M. Goroll, H. Preu, J. Keller, L. Ernst, B. Michel, B. Wunderle","doi":"10.1109/ESIME.2012.6191761","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191761","url":null,"abstract":"Interfacial delamination has become one of the most important reliability issues in the microelectronic industry, and therefore more and more focus is set on related research. Critical interface fracture data are rarely given in literature. These data sets are very important for subsequent proceedings like failure modeling, lifetime prediction and design evaluation associated with reliability. A fast measurement method could be very helpful for the qualification and evaluation of technologies and products. Usually measurements deal with artificial samples putting a lot of efforts to produce them as close as possible to the product containing the materials, surface treatments and fabrication conditions from the product. It is costly and time consuming to prepare production-like samples. We show the first version of a newly developed loading device, called micro Mixed Mode Tester (μMMT), for samples cut from real packages, which are production samples. This approach enables us to obtain critical fracture data of the lead frame interfaces in microelectronic packages. The interfaces we look at consist of the partners Cu-Lead frame (Cu) with epoxy-based Molding Compound (MC) or epoxy-based Glue-Die Attach (DA). The main advantage of using production samples is that the specimens contain all the impacts associated with the manufacturing and processing of the products. The newly developed method has the potential to become a standard test solution for interface toughness measurements, optimized with respect to analyzability, reproducibility, stability and total test cost and allows us to obtain more accurate values of the interfacial toughness. The evaluation of the critical data with respect to interfacial fracture mechanics needs experiments and simulations to be carried out in parallel. The focus of this work is set on the experimental data as the first step.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"232 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115967163","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":"A multivariate parameter analysis of copper pillars eases the design of denser interconnects","authors":"G. Schlottig, T. Brunschwiler, J. Goicochea, W. Escher, B. Michel","doi":"10.1109/ESIME.2012.6191778","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191778","url":null,"abstract":"Electronic packaging increasingly aims at copper pillars as an interconnect concept, because of their benefits for fine pitches, high aspect ratios, high electromigration stability and excellent thermal conductivity. The thermal expansion and high stiffness of the pillars remains a design challenge when building-up more copper volume close to the silicon die. Specific pillar geometries and structured underfills have been suggested but included only few parameter variations. To gain profound insight into the thermo-mechanical aspects of copper pillars we present a parametric finite element approach and an according multivariate analysis of the design space. We chose a 3D slice model to represent a copper pillar matrix and varied height, width and thickness at a constant pitch to consider different aspect ratios and cross sections, and vary the material's CTE and Young's modulus. The general assumption of aiming higher columns without underfill as the most compliant design when controlling for BEoL layer thickness must be rejected. If exploiting the multivariate design space wholly, processing steps may be eliminated, such as structuring an underfill layer. Tailoring the CTE may be used to lower the stress level for a desired aspect ratio, and the ratio of Cu volume to total pillar layer volume should be considered. To accommodate the display of multivariate stress results we propose an appropriate small multiple visualization.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"93 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113954886","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":"Evaluation of quasi-hermetic packaging solutions for active microwave devices and space applications","authors":"W. Ben Naceur, N. Malbert, N. Labat, H. Frémont, J. Muraro, P. Monfraix","doi":"10.1109/ESIME.2012.6191705","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191705","url":null,"abstract":"A methodology is proposed to estimate the actual influence of important factors during steady-state Temperature Humidity Bias (THB) aging tests on SiN-passivated MMICs: temperature-humidity effects, bias conditions and protection by silica-filled epoxy resins dispensed by a dam-and-fill process. In this work, accelerated aging tests on microwave devices used for space applications were carried out, with or without bias. After 3000 hours of storage at 85°C/85%RH, there was no catastrophic failure. Only devices with PHEMT showed electrical degradations of some DC electrical parameters after 1000 hours of test. In another 1600 hours series of tests, bias parameter was added. Devices with PHEMT exhibited electrical breakdowns, especially under reverse biasing of the gate-source junction and before the required 1000 hours of test. The failed parts were localized by surface observation using optical and scanning electron microscopy. The failure electrical signatures were correlated by electrical simulations. In order to prepare future investigation on encapsulated devices, it was determined moisture diffusivity and content at saturation of commercial dam and fill resins. The actual protection time and the effects of bias conditions of encapsulated MMICs during THB tests were specified. These parameters can be taken into account for further analysis of the reliability of encapsulated active microwave devices for space applications.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133248517","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":"Experimental assessment of flat-type photovoltaic module thermal behavior","authors":"S. Bojanampati, P. Rodgers, V. Eveloy","doi":"10.1109/ESIME.2012.6191695","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191695","url":null,"abstract":"The electrical performance and reliability of flat-type photovoltaic (PV) modules can be severely affected by elevated cell operating temperature in regions benefiting from high yearly solar irradiation levels, due to elevated ambient temperatures. In this work the potential of active cooling solutions to enhance flat-type PV module electrical performance, consisting of forced air- and water-cooling, is experimentally explored on laboratory-scale prototypes operated indoors under different light source illuminance levels. Forced-air and water-cooling are implemented using a duct-axial fan configuration and chilled water channel, respectively, both attached to the module non-active surface. In both cooling configurations, the cooling fluid directly wets the module non-active surface, thereby eliminating thermal contact resistance. Forced air-cooling is found to improve module peak output power by approximately 10% relative to passive cooling, in an ambient temperature of 21°C. The output power of water-cooled modules increases by 48% using unchilled water at a temperature 21°C, and by 66% and 69% using chilled water at 14°C and 5°C, respectively, relative to passive cooling. The experiments conducted therefore provide an order-of-magnitude assessment of the technical feasibility of different active cooling strategies before characterizing commercial modules under solar irradiation conditions.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"160 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134175124","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":"A cost-effective active cooling method: Thermal performance and cost analysis","authors":"Sheng Liu, Ling Xu, Mingxiang Chen","doi":"10.1109/ESIME.2012.6191805","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191805","url":null,"abstract":"This paper presents an active cooling method for power electronics devices especially for insulated gate bipolar transistors (IGBT) modules. This method is a kind of liquid cooling, which utilizes the excellent cooling ability of flowing water and bring the heat out of the module through the base plate embedded with micro-channel. Finite element analysis is used to judge the thermal performance, the highest temperature and the temperature uniformity are uniquely concerned. The results showed that this method could satisfy the heat dissipation need of devices with high power densities. Besides, this method relies on the performance, cost and reliability of the pump. A tiny and powerful micro pump would make this active cooling method become practical. However, this kind of micro pumps is usually very expensive. Thus the cost analysis was done to decide whether this kind of cooling method could be used widely in industry.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"50 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114024556","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":"FEM stress analysis in BGA components subjected to JEDEC drop test applying high strain rate lead-free solder material models","authors":"F. Kraemer, K. Meier, S. Wiese, S. Rzepka","doi":"10.1109/ESIME.2012.6191779","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191779","url":null,"abstract":"The influence of the strain rate dependent yield properties of solder is often neglected in the FEM analyses of JEDEC drop tests. In this paper the effect of this material behavior was tested in drop test simulations of productive BGA components, in order to evaluate the resulting stress distribution and levels in the 2nd level interconnects. Two lead free solder alloys SnAg1.3CuO.5 (SAC1305) and SnAg3.5 (SA35) were characterized in a high strain rate tensile tester in a range of 40s-1 to 800s-1. The specimens were produced in a casting process with a high stress dimension close to real solder joints, in order to create similar size effects. The stress-strain behavior was recorded with high resolution using strain gauge sensors. The evaluation of the yield stress dependency on strain rate was done by the measured stress data. Hereby the SACI305 solder revealed a high sensitivity of yield stress on the applied strain rate, while the SA35 solder marginally increased its yield stress. The influence of both strain rate dependent solder models on the interconnection stress distribution was tested against a simple bilinear and an elastic material model. The simple solder models cause excessive stress in the copper pads of substrate and PCB due to their high and neglected yield behavior, respectively. The accurate solder models significantly reduce the copper stress by generating locally higher plastic deformations and a wider distribution of plastic strain in the solder balls. The different strain rate sensitivity affects the distribution of plastic strain between solder and copper. High strain rate sensitive solders reduce the plastic strain in the solder with higher PCB deformations and increase the stress and strain in the copper compared to materials with a low sensitivity. The application of strain rate dependent solder material models is necessary for realistic stress interpretations in drop test conditions. The neglect of this material behavior leads to unrealistic stress distributions and thus, it leads to wrong failure assumptions and lifetime predictions.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115662206","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":"Molecular modeling of the conductivity changes of the emeraldine base polyaniline due to protonic acid doping","authors":"Xianping Chen, Cadmus Yuan, Cell K. Y. Wong, Guoqi Zhang","doi":"10.1109/ESIME.2012.6191741","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191741","url":null,"abstract":"We propose a molecular modeling strategy, which is capable of predicting the conductivity change of emeraldine base polyaniline polymer due to different degree of protonic acid doping. The method is comprised of two key steps: (1) generating the amorphous unit cells with given number of polymer molecules and different concentration of H+ ions by Monte Carlo algorithm; (2) modeling the doping chemical reaction by using a scripted loop control molecular mechanics/molecular dynamics simulation. This modeling strategy can be used for optimal/robust selection and design of conductive polymers for various applications.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"282 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114456394","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":"Advanced mixed-mode bending test: A rapid, inexpensive and accurate method for fracture-mechanical interface characterisation","authors":"B. Wunderle, M. Schulz, J. Keller, D. May, I. Maus, H. Pape, B. Michel","doi":"10.1109/ESIME.2012.6191698","DOIUrl":"https://doi.org/10.1109/ESIME.2012.6191698","url":null,"abstract":"This paper presents a comprehensive method for obtaining urgently required critical interface delamination data of material pairings used in electronic packaging. The objective is to thereby enable rapid, inexpensive and accurate lifetime prediction for that failure mode. A new testing method is presented which allows maximum mode-angle range and enhanced throughput testing under multiple loading conditions, the coverage of which is usually a rather lengthy and resource-demanding procedure. The approach is specimen-centred in the sense that the accent is put on test-specimens which are easily manufacturable industrially, rather than having to adapt them to a special testing machine. The concept is also scalable, i.e. it has potential to work also for smaller samples cut from real devices. We show the first version of a newly developed test-stand and discuss the obtained results for copper-molding compound interfaces in the light of the current state of the art used for delamination testing in electronic packaging.","PeriodicalId":319207,"journal":{"name":"2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123939878","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}