2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)最新文献
Pub Date : 2019-03-01DOI: 10.1109/eurosime.2019.8724518
M. Frewein, T. Krivec, Q. Tao, J. Zuendel, J. Rosc, M. Gschwandl, P. Fuchs
In manufacturing of electronic packages, especially modules manufactured in a panel level based packaging process, the occurring package warpage is always one of the most critical issues. The deformation of manufactured packages is generally triggered by dimensional changes in the material layers due to thermal expansion and chemical shrinkage during the curing process. Being able to predict the occurring warpage can significantly improve design quality and reliability of electronic systems. The current study deals with the application of finite element simulation to predict the warpage after manufacturing and singularization of a fine line structured multi-die package manufactured in a panel level packaging process. For defining the material properties of the applied dielectric materials, temperature dependent linear elastic models were applied considering the temperature dependency of the materials as well as their orthotropy were applicable. For b-staged resins, a coefficient of chemical shrinkage was determined and implemented in the material model. Copper properties were modelled considering temperature dependency and plasticity while directional effects in copper were neglected. All applied material models have been determined in the course of the project. The package structure was modelled in ABAQUS ®, one of the industry standard multi-physics simulation packages, applying a homogenization approach resulting in a rather small but still accurate model of the package. The boundary conditions were specified based on the actual manufacturing conditions in the production line of the package. Finally the calculated, resulting deformation of the package was compared to the actually measured deformation of the packages, where cross-sectioning profilometry, Shadow Moire methodology and X-ray tomography and have been applied to create the validation data. Based on the presented results it could be shown that the applied finite element simulation approach is suitable for describing the warpage occurring during panel level packaging of electronic modules.
{"title":"Package Level Warpage Simulation of a Fan Out System in Board Module","authors":"M. Frewein, T. Krivec, Q. Tao, J. Zuendel, J. Rosc, M. Gschwandl, P. Fuchs","doi":"10.1109/eurosime.2019.8724518","DOIUrl":"https://doi.org/10.1109/eurosime.2019.8724518","url":null,"abstract":"In manufacturing of electronic packages, especially modules manufactured in a panel level based packaging process, the occurring package warpage is always one of the most critical issues. The deformation of manufactured packages is generally triggered by dimensional changes in the material layers due to thermal expansion and chemical shrinkage during the curing process. Being able to predict the occurring warpage can significantly improve design quality and reliability of electronic systems. The current study deals with the application of finite element simulation to predict the warpage after manufacturing and singularization of a fine line structured multi-die package manufactured in a panel level packaging process. For defining the material properties of the applied dielectric materials, temperature dependent linear elastic models were applied considering the temperature dependency of the materials as well as their orthotropy were applicable. For b-staged resins, a coefficient of chemical shrinkage was determined and implemented in the material model. Copper properties were modelled considering temperature dependency and plasticity while directional effects in copper were neglected. All applied material models have been determined in the course of the project. The package structure was modelled in ABAQUS ®, one of the industry standard multi-physics simulation packages, applying a homogenization approach resulting in a rather small but still accurate model of the package. The boundary conditions were specified based on the actual manufacturing conditions in the production line of the package. Finally the calculated, resulting deformation of the package was compared to the actually measured deformation of the packages, where cross-sectioning profilometry, Shadow Moire methodology and X-ray tomography and have been applied to create the validation data. Based on the presented results it could be shown that the applied finite element simulation approach is suitable for describing the warpage occurring during panel level packaging of electronic modules.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115862632","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}
Pub Date : 2019-03-01DOI: 10.1109/EUROSIME.2019.8724539
K. Buehler, G. Lorenz, M. Mittag, U. Krieger, Niclas Heise, S. Wicht, R. Gerbach, F. Naumann
Micro-Transfer-Printing ($mu$ TP) as an alternative micro-assembly technology opens up new possibilities in the integration and packaging of smart devices like processed III/V devices, optical filters and special sensors on CMOS and MEMS on wafer-level. The technology uses an elastomer stamp to manipulate multiple printable components at the same time that are difficult to handle because of their size or fragility. Nevertheless, the industrial application of this technology as well as the transfer and upscaling from laboratory scale is still challenging. In order to realize a reliable printing process with sufficient yield, the interaction of the components to be printed, their fixation by tether structures to the source wafer and the adhesion of the transfer stamp must be well adapted. Therefore, the presented work will deal with results of mechanical experiments and FEA-modelling in order to get a deeper understanding of the $mu$ TP-process and will allow a defined tether layout and optimization of the processed source wafers.
{"title":"Micro-Transfer-Printing and Potential Process Optimizations by FEA","authors":"K. Buehler, G. Lorenz, M. Mittag, U. Krieger, Niclas Heise, S. Wicht, R. Gerbach, F. Naumann","doi":"10.1109/EUROSIME.2019.8724539","DOIUrl":"https://doi.org/10.1109/EUROSIME.2019.8724539","url":null,"abstract":"Micro-Transfer-Printing ($mu$ TP) as an alternative micro-assembly technology opens up new possibilities in the integration and packaging of smart devices like processed III/V devices, optical filters and special sensors on CMOS and MEMS on wafer-level. The technology uses an elastomer stamp to manipulate multiple printable components at the same time that are difficult to handle because of their size or fragility. Nevertheless, the industrial application of this technology as well as the transfer and upscaling from laboratory scale is still challenging. In order to realize a reliable printing process with sufficient yield, the interaction of the components to be printed, their fixation by tether structures to the source wafer and the adhesion of the transfer stamp must be well adapted. Therefore, the presented work will deal with results of mechanical experiments and FEA-modelling in order to get a deeper understanding of the $mu$ TP-process and will allow a defined tether layout and optimization of the processed source wafers.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127647886","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}
Pub Date : 2019-03-01DOI: 10.1109/EUROSIME.2019.8724560
K. Kariya, Naoaki Tsurumi, T. Maekawa, Mitsuru Morimoto, N. Masago
Prediction of warpage behaviors of semiconductor packages is the most fundamental work for their reliability design. Thus, it is also essential to simulate the fracture of the packages. In this paper, three different test samples were prepared to predict the warpages from the assembly process and material properties by finite element method. From the comparison between experimental study and numerical calculation, it seemed that the initial warpage of the samples was close to zero during the molding process of epoxy-mold-compound (EMC) due to the pressing of a metal mold onto the warping samples. Thus, the warpage of the samples after the molding process could be roughly predicted by using the stress free temperature of EMC defined as the molding temperature in this paper. Furthermore, we found that the calculation including the contribution of the chemical shrinkage of EMC was more effective to simulate the warpages.
{"title":"Thermal Warpage Behavior Analysis of Semiconductor Packages","authors":"K. Kariya, Naoaki Tsurumi, T. Maekawa, Mitsuru Morimoto, N. Masago","doi":"10.1109/EUROSIME.2019.8724560","DOIUrl":"https://doi.org/10.1109/EUROSIME.2019.8724560","url":null,"abstract":"Prediction of warpage behaviors of semiconductor packages is the most fundamental work for their reliability design. Thus, it is also essential to simulate the fracture of the packages. In this paper, three different test samples were prepared to predict the warpages from the assembly process and material properties by finite element method. From the comparison between experimental study and numerical calculation, it seemed that the initial warpage of the samples was close to zero during the molding process of epoxy-mold-compound (EMC) due to the pressing of a metal mold onto the warping samples. Thus, the warpage of the samples after the molding process could be roughly predicted by using the stress free temperature of EMC defined as the molding temperature in this paper. Furthermore, we found that the calculation including the contribution of the chemical shrinkage of EMC was more effective to simulate the warpages.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123351297","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}
Pub Date : 2019-03-01DOI: 10.1109/EUROSIME.2019.8724513
P. Zając, M. Szermer, Piotr Amrozik, C. Maj, G. Jablonski
During the design of acceleration measuring system, the optimal choice of sensor parameters may only be made by careful analysis of both the MEMS sensor itself and the readout circuit. Therefore, a coupled electromechanical simulation is usually required. In this paper, we use such a simulation to determine the values of modulation voltage and switching frequency which ensure that the relative readout error is within acceptable limits. Three capacitive MEMS accelerometer structures are analyzed and the relative error due to the impact of electrostatic force is quantified. Based on these results, the recommendations about the optimal readout circuit parameters are given.
{"title":"Coupled Electro-mechanical Simulation of Capacitive MEMS Accelerometer for Determining Optimal Parameters of Readout Circuit","authors":"P. Zając, M. Szermer, Piotr Amrozik, C. Maj, G. Jablonski","doi":"10.1109/EUROSIME.2019.8724513","DOIUrl":"https://doi.org/10.1109/EUROSIME.2019.8724513","url":null,"abstract":"During the design of acceleration measuring system, the optimal choice of sensor parameters may only be made by careful analysis of both the MEMS sensor itself and the readout circuit. Therefore, a coupled electromechanical simulation is usually required. In this paper, we use such a simulation to determine the values of modulation voltage and switching frequency which ensure that the relative readout error is within acceptable limits. Three capacitive MEMS accelerometer structures are analyzed and the relative error due to the impact of electrostatic force is quantified. Based on these results, the recommendations about the optimal readout circuit parameters are given.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125705797","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}
Pub Date : 2019-03-01DOI: 10.1109/EUROSIME.2019.8724578
A. Salahouelhadj, M. Gonzalez, K. Vanstreels, A. Podpod, A. Phommahaxay, K. Rebibis, E. Beyne
Wafer warpage is a big challenge during wafer process in Fan-Out Wafer-Level-Packaging (FOWLP). It is crucial to keep warpage low as much as possible for successful process integration. The warpage is mainly due to the Coefficient of Thermal Expansion (CTE) mismatch between the involved materials during temperature changes. Furthermore, warpage of molded wafers depends on material properties. Therefore, accurate material characterization has great importance. In this paper, thermal-mechanical properties of the used polymeric materials were measured using nanoindentation and Stereo-Digital Image Correlation (SDIC). In this study, warpage of molded wafers with and without Temporary Bonding Adhesive (TBA) is investigated during heating to 200°C and cooling down to room temperature. SDIC technique was used to measure the warpage of molded wafers. Finally, Finite Element (FE) simulations were carried out using as input the measured thermal-mechanical properties. A comparison between warpage measurements and FE simulation at different temperatures showed a good agreement.
{"title":"Study of wafer warpage for Fan-Out wafer level packaging: finite element modelling and experimental validation","authors":"A. Salahouelhadj, M. Gonzalez, K. Vanstreels, A. Podpod, A. Phommahaxay, K. Rebibis, E. Beyne","doi":"10.1109/EUROSIME.2019.8724578","DOIUrl":"https://doi.org/10.1109/EUROSIME.2019.8724578","url":null,"abstract":"Wafer warpage is a big challenge during wafer process in Fan-Out Wafer-Level-Packaging (FOWLP). It is crucial to keep warpage low as much as possible for successful process integration. The warpage is mainly due to the Coefficient of Thermal Expansion (CTE) mismatch between the involved materials during temperature changes. Furthermore, warpage of molded wafers depends on material properties. Therefore, accurate material characterization has great importance. In this paper, thermal-mechanical properties of the used polymeric materials were measured using nanoindentation and Stereo-Digital Image Correlation (SDIC). In this study, warpage of molded wafers with and without Temporary Bonding Adhesive (TBA) is investigated during heating to 200°C and cooling down to room temperature. SDIC technique was used to measure the warpage of molded wafers. Finally, Finite Element (FE) simulations were carried out using as input the measured thermal-mechanical properties. A comparison between warpage measurements and FE simulation at different temperatures showed a good agreement.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133417899","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}
Pub Date : 2019-03-01DOI: 10.1109/EUROSIME.2019.8724550
M. Stadler
To guarantee a high level of solder joint durability for soft solder die attach, a uniform bond line thickness is crucial. In addition, for high electrical performance, a low void concentration is desirable. However, these goals are difficult to achieve during reflow soldering. The die tilt and the formation of voids are mainly controlled by fluid forces. We develop a fluid dynamical model to better understand these mechanisms. The model is validated using experimental data. In order to use the model for design improvement, the simulation model is coupled with a genetic optimization algorithm. This arrangement can help to develop designs which lead to (a) uniform bond line thickness and (b) minimal void concentration. Furthermore, advanced search strategies act as an enabler for the generation of innovative design features. They may in turn foster the formulation of new intellectual property. To illustrate the spectrum of possible application scenarios, we show three industrial use cases.
{"title":"Numerical Simulation of Reflow Soldering","authors":"M. Stadler","doi":"10.1109/EUROSIME.2019.8724550","DOIUrl":"https://doi.org/10.1109/EUROSIME.2019.8724550","url":null,"abstract":"To guarantee a high level of solder joint durability for soft solder die attach, a uniform bond line thickness is crucial. In addition, for high electrical performance, a low void concentration is desirable. However, these goals are difficult to achieve during reflow soldering. The die tilt and the formation of voids are mainly controlled by fluid forces. We develop a fluid dynamical model to better understand these mechanisms. The model is validated using experimental data. In order to use the model for design improvement, the simulation model is coupled with a genetic optimization algorithm. This arrangement can help to develop designs which lead to (a) uniform bond line thickness and (b) minimal void concentration. Furthermore, advanced search strategies act as an enabler for the generation of innovative design features. They may in turn foster the formulation of new intellectual property. To illustrate the spectrum of possible application scenarios, we show three industrial use cases.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134056894","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}
Pub Date : 2019-03-01DOI: 10.1109/EUROSIME.2019.8724579
H. Gao, P. Gijsenbergh, S. Mao, A. Halbach, Y. Jeong, D. Cheyns, X. Rottenberg, V. Rochus
Mid-air acoustic holographic techniques allow the tempo-spatial reconstruction of the desired wave profile (in amplitude and/or phase), driving novel applications such as particle trapping and haptics in air. Piezoelectric micro-machined ultrasound transducer (pMUT) remains promising for these applications due to its potential to build up high density, cost effective phase arrays compatible with drive electronics. For this purpose, we characterized in-house fabricated discrete pMUT devices and assumed each element of pMUT phase array performs the same in this paper. Using these parameters as input of $25 times 25$ pMUT arrays, we mainly demonstrated three different acoustic projection methodologies for reconstructing mid-air acoustic holograms 1 cm distant from the aperture by simulations: pure pseudo-inverse (PINV) algorithm, PINV algorithms together with iterative weighting, PINV methods integrated with Tikhonov regularization. The resulting drive performance of pMUT array, calculated as transducer drive efficiency for variant acoustic holograms, was increased by 3-6 times when adding iterative weighting or Tikhonov regularization. The trade-off was the side lobes distributed across the final pressure field compared to the reference of PINV but Tikhonov regularization outperformed iterative weighting especially in the central region.
{"title":"Reconstructing mid-air acoustic holograms using PMUT arrays: a simulation study","authors":"H. Gao, P. Gijsenbergh, S. Mao, A. Halbach, Y. Jeong, D. Cheyns, X. Rottenberg, V. Rochus","doi":"10.1109/EUROSIME.2019.8724579","DOIUrl":"https://doi.org/10.1109/EUROSIME.2019.8724579","url":null,"abstract":"Mid-air acoustic holographic techniques allow the tempo-spatial reconstruction of the desired wave profile (in amplitude and/or phase), driving novel applications such as particle trapping and haptics in air. Piezoelectric micro-machined ultrasound transducer (pMUT) remains promising for these applications due to its potential to build up high density, cost effective phase arrays compatible with drive electronics. For this purpose, we characterized in-house fabricated discrete pMUT devices and assumed each element of pMUT phase array performs the same in this paper. Using these parameters as input of $25 times 25$ pMUT arrays, we mainly demonstrated three different acoustic projection methodologies for reconstructing mid-air acoustic holograms 1 cm distant from the aperture by simulations: pure pseudo-inverse (PINV) algorithm, PINV algorithms together with iterative weighting, PINV methods integrated with Tikhonov regularization. The resulting drive performance of pMUT array, calculated as transducer drive efficiency for variant acoustic holograms, was increased by 3-6 times when adding iterative weighting or Tikhonov regularization. The trade-off was the side lobes distributed across the final pressure field compared to the reference of PINV but Tikhonov regularization outperformed iterative weighting especially in the central region.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132971853","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}
Pub Date : 2019-03-01DOI: 10.1109/eurosime.2019.8724506
R. Duca, M. O. Ghidoni
Sensor technology has become relevant to all aspects of life. Sensors have become central to everyday applications related to safety, security, health and consumer leisure. Sensors are also significantly present in industrial applications such as process control and monitoring. Consumer applications such as smart phones and wearables are nowadays increasing the integrity of various different sensors, significantly augmenting the final product functionality.In order to increase this functionality, maintain application at reasonable size and to increase the room left to the device battery, a drive for device miniaturization is introduced. This need becomes a challenging task at all levels of product cycle from design and virtual characterization up to assembly and testing characterization.This paper will present a methodology developed and employed at finite element modeling (FEM) stage in order to support virtual characterization for device miniaturization at design stage for a MEMS sensor package. All the aspects considered for virtual characterization shall be presented. The target of this methodology is to provide a useful guideline for package designers at an early stage of product development.
{"title":"Design for Package Miniaturization for a MEMS Pressure Sensor","authors":"R. Duca, M. O. Ghidoni","doi":"10.1109/eurosime.2019.8724506","DOIUrl":"https://doi.org/10.1109/eurosime.2019.8724506","url":null,"abstract":"Sensor technology has become relevant to all aspects of life. Sensors have become central to everyday applications related to safety, security, health and consumer leisure. Sensors are also significantly present in industrial applications such as process control and monitoring. Consumer applications such as smart phones and wearables are nowadays increasing the integrity of various different sensors, significantly augmenting the final product functionality.In order to increase this functionality, maintain application at reasonable size and to increase the room left to the device battery, a drive for device miniaturization is introduced. This need becomes a challenging task at all levels of product cycle from design and virtual characterization up to assembly and testing characterization.This paper will present a methodology developed and employed at finite element modeling (FEM) stage in order to support virtual characterization for device miniaturization at design stage for a MEMS sensor package. All the aspects considered for virtual characterization shall be presented. The target of this methodology is to provide a useful guideline for package designers at an early stage of product development.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"23 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133271930","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}
Pub Date : 2019-03-01DOI: 10.1109/EUROSIME.2019.8724546
Ying Yang, P. M. Souare, J. Sylvestre
In order to better understand the initiation of crack defects and predict the thermo-mechanical failure of underfill in microelectronic packages, a confocal microscopy-based digital image correlation (confocal-DIC) method was developed to measure the underfill local strain directly. A special underfill, consisting of transparent epoxy with Al2O3 particle fillers, was applied to meet the requirement of confocal imaging inside the resin. A preliminary validation was accomplished on two samples with a simple structure: (a) non-constrained sample for isotropic dilatation and (b) a thin-layer sample for strain gradients in the resin on a glass substrate. Results from both samples were in good agreement with the calculation from the coefficient of thermal expansion (CTE) or the numerical simulation from finite element method (FEM). Furthermore, we applied this technique to measure the strain distribution in the underfill at the chip corner area when the assembly was under thermal loading at 60 °C. The results showed that the maximum strain value appeared exactly at the chip corner area, which is consistent to the simulation results. The measured maximum first principle strain reached around 0.9 %, while the strain on the sidewalls was approximately 0.5 %. Due to the imperfections of the real corner resulting from dicing effects, the measured strain at the corner was lower than the FEM result. In general, the good agreement between measurements and calculations demonstrates the accuracy of our methodology for measuring the underfill local strain in microelectronic packaging assemblies.
{"title":"Direct Measurements of Underfill Local Strain Using Confocal Microscopy and Digital Image Correlation","authors":"Ying Yang, P. M. Souare, J. Sylvestre","doi":"10.1109/EUROSIME.2019.8724546","DOIUrl":"https://doi.org/10.1109/EUROSIME.2019.8724546","url":null,"abstract":"In order to better understand the initiation of crack defects and predict the thermo-mechanical failure of underfill in microelectronic packages, a confocal microscopy-based digital image correlation (confocal-DIC) method was developed to measure the underfill local strain directly. A special underfill, consisting of transparent epoxy with Al2O3 particle fillers, was applied to meet the requirement of confocal imaging inside the resin. A preliminary validation was accomplished on two samples with a simple structure: (a) non-constrained sample for isotropic dilatation and (b) a thin-layer sample for strain gradients in the resin on a glass substrate. Results from both samples were in good agreement with the calculation from the coefficient of thermal expansion (CTE) or the numerical simulation from finite element method (FEM). Furthermore, we applied this technique to measure the strain distribution in the underfill at the chip corner area when the assembly was under thermal loading at 60 °C. The results showed that the maximum strain value appeared exactly at the chip corner area, which is consistent to the simulation results. The measured maximum first principle strain reached around 0.9 %, while the strain on the sidewalls was approximately 0.5 %. Due to the imperfections of the real corner resulting from dicing effects, the measured strain at the corner was lower than the FEM result. In general, the good agreement between measurements and calculations demonstrates the accuracy of our methodology for measuring the underfill local strain in microelectronic packaging assemblies.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124997074","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}
Pub Date : 2019-03-01DOI: 10.1109/EUROSIME.2019.8724582
R. Sethu, Hansika Jayawardana, K. Soon, A. Chai
The constitutive equation model for a particular aluminum thin film deposited using Physical Vapor Deposition (PVD) process used in wafer fabrication Back End of Line (BEOL) has been determined by matching the data from experimental nanoindentation and Finite Element Analysis (FEA) simulation. The model used is a derivative of the Voce isotropic hardening model which is defined by three coefficients. The Linear Hardening Coefficient, Saturation Flow Stress and Saturation Exponent has been determined to be 21937 MPa, 135 MPa and 25 respectively.
{"title":"Determination of BEOL Aluminum-Copper Constitutive Equation using FEA Simulation and Response Surface Methodology","authors":"R. Sethu, Hansika Jayawardana, K. Soon, A. Chai","doi":"10.1109/EUROSIME.2019.8724582","DOIUrl":"https://doi.org/10.1109/EUROSIME.2019.8724582","url":null,"abstract":"The constitutive equation model for a particular aluminum thin film deposited using Physical Vapor Deposition (PVD) process used in wafer fabrication Back End of Line (BEOL) has been determined by matching the data from experimental nanoindentation and Finite Element Analysis (FEA) simulation. The model used is a derivative of the Voce isotropic hardening model which is defined by three coefficients. The Linear Hardening Coefficient, Saturation Flow Stress and Saturation Exponent has been determined to be 21937 MPa, 135 MPa and 25 respectively.","PeriodicalId":357224,"journal":{"name":"2019 20th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121034805","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}
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