Pub Date : 2006-04-24DOI: 10.1109/ESIME.2006.1644044
M. Rollig, S. Wiese, K. Wolter
A modern approach to determine material data of solder alloys such as SnAg and SnAgCu is to measure the mechanical behaviour direct on a CSP/BGA solder connection. Advantages of that technique of measurement on industrial manufactured solder bumps are the considerations of miniaturized volumes and the material diffusion from connection pad into the alloy during reflow soldering process. Compared to the tensile test the shear experiment differs in the way of initiation the force load into the solder alloy. The shear force load inducts a multiaxial state of stress. This is the reason for the confrontation with a higher effort into the conversion procedure to determine specific coefficients for the material law. In several publications creep data were published based on shear force load measurements and applied cylinder model to convert primary data into equivalent values. In practice, the specimen bumps may have been different in their shape, depending on pad geometry, solder volume and weight of electronic component. How does the shape of solder joints influence the creep behaviour? A form parameter has been introduced to be able to describe a wide range of solder bump shapes. Every bump shape from barrel to hyperbolic can now be regarded. The form parameter also takes place in the conversion of experimental data into equivalent data. The determined creep material laws, based on the improved analytic model, describe the deformation behaviour of solder joints more accurately, than the commonly assigned creep laws using the pure cylinder model. The shape effect is shown on a FEM analysis of the experimental setup of creep measurements on shape varied Sn96.5Ag3.5 solder bumps. In general, during FEM based material modelling the coefficients of the material laws need to be stepwise changed until the right behaviour occurs. These iterations can stretch over a long time. The improved analytical model shows the potential to shorten the coefficient determination of material laws
{"title":"Extraction of material parameters for creep experiments on real solder-joints by FE analysis","authors":"M. Rollig, S. Wiese, K. Wolter","doi":"10.1109/ESIME.2006.1644044","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644044","url":null,"abstract":"A modern approach to determine material data of solder alloys such as SnAg and SnAgCu is to measure the mechanical behaviour direct on a CSP/BGA solder connection. Advantages of that technique of measurement on industrial manufactured solder bumps are the considerations of miniaturized volumes and the material diffusion from connection pad into the alloy during reflow soldering process. Compared to the tensile test the shear experiment differs in the way of initiation the force load into the solder alloy. The shear force load inducts a multiaxial state of stress. This is the reason for the confrontation with a higher effort into the conversion procedure to determine specific coefficients for the material law. In several publications creep data were published based on shear force load measurements and applied cylinder model to convert primary data into equivalent values. In practice, the specimen bumps may have been different in their shape, depending on pad geometry, solder volume and weight of electronic component. How does the shape of solder joints influence the creep behaviour? A form parameter has been introduced to be able to describe a wide range of solder bump shapes. Every bump shape from barrel to hyperbolic can now be regarded. The form parameter also takes place in the conversion of experimental data into equivalent data. The determined creep material laws, based on the improved analytic model, describe the deformation behaviour of solder joints more accurately, than the commonly assigned creep laws using the pure cylinder model. The shape effect is shown on a FEM analysis of the experimental setup of creep measurements on shape varied Sn96.5Ag3.5 solder bumps. In general, during FEM based material modelling the coefficients of the material laws need to be stepwise changed until the right behaviour occurs. These iterations can stretch over a long time. The improved analytical model shows the potential to shorten the coefficient determination of material laws","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"58 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81573798","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 : 2006-04-24DOI: 10.1109/ESIME.2006.1644010
A. Syed
There are two sources of errors in any finite element based life prediction model: the finite element mesh and assumptions, and the material properties used -specifically the constitutive model used to describe the behavior of solder joints during temperature cycling. The use of these assumptions may prohibit the application of life prediction model to conditions beyond the ones used to develop the model. The author has previously proposed life prediction models for SnPb and SnAgCu solder joints using advanced finite element modeling techniques such as sub-structuring and multi-point constraints. The assumptions were necessary to increase the efficiency of solution with available computing power. With the advances in computing technology, these assumptions are no longer necessary, and more accurate life prediction can be achieved by eliminating most of the modeling assumptions. In this paper, the updated life prediction model parameters for SnAgCu solder joints are presented without the use of sub-structuring and multi-point constraints. All joints for a particular package-board interconnection are modeled as having non-linear properties. In addition, a detailed mesh refinement study is done to determine the minimum mesh density required to yield near mesh-independent results. In addition to modeling assumptions, the constitutive equation used for solder joints may also influence the life prediction model parameters. To investigate this further, the creep behavior of SnAgCu solder joints is represented by using published constitutive equations (double power law creep and hyperbolic sine equation). The results show a significant influence of constitutive equation on creep strain based life prediction model but minimum impact when energy density based approach is used
{"title":"Updated Life Prediction Models for Solder Joints with Removal of Modeling Assumptions and Effect of Constitutive Equations","authors":"A. Syed","doi":"10.1109/ESIME.2006.1644010","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644010","url":null,"abstract":"There are two sources of errors in any finite element based life prediction model: the finite element mesh and assumptions, and the material properties used -specifically the constitutive model used to describe the behavior of solder joints during temperature cycling. The use of these assumptions may prohibit the application of life prediction model to conditions beyond the ones used to develop the model. The author has previously proposed life prediction models for SnPb and SnAgCu solder joints using advanced finite element modeling techniques such as sub-structuring and multi-point constraints. The assumptions were necessary to increase the efficiency of solution with available computing power. With the advances in computing technology, these assumptions are no longer necessary, and more accurate life prediction can be achieved by eliminating most of the modeling assumptions. In this paper, the updated life prediction model parameters for SnAgCu solder joints are presented without the use of sub-structuring and multi-point constraints. All joints for a particular package-board interconnection are modeled as having non-linear properties. In addition, a detailed mesh refinement study is done to determine the minimum mesh density required to yield near mesh-independent results. In addition to modeling assumptions, the constitutive equation used for solder joints may also influence the life prediction model parameters. To investigate this further, the creep behavior of SnAgCu solder joints is represented by using published constitutive equations (double power law creep and hyperbolic sine equation). The results show a significant influence of constitutive equation on creep strain based life prediction model but minimum impact when energy density based approach is used","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"6 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83851697","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 : 2006-04-24DOI: 10.1109/ESIME.2006.1644046
E. Chan, H. Fan, M. Yuen
Understanding interfacial adhesion subjected to different levels of moisture content and temperature elevation is of significant interest to the electronic packaging industry. The conventional study has focused primary on moisture diffusion into the encapsulated molding compound (EMC) of plastic packages. This paper looks at the alternative path of interfacial seepage into the EMC and copper interface of the IC package. In this study, the effect of moisture on interfacial bonding energy was calculated by running a molecular dynamics simulation. A series of MD models consisting of a network of epoxy macromolecules and copper atoms with different amount of water molecules at its interface were built with the Discover module. The mass ratio of water molecules to epoxy varied from 1% to 6% while the surrounding temperature kept at 85degC in order to simulate a similar environment condition in MSL-1 qualification test. Calculations were carried out at different humidity level with a prescribed moisture concentration value, using the NVT ensembles. From the simulation results, it is observed that the interfacial bonding energy decreases with the increase of mass ratio of water molecule to the epoxy due to locking of water molecules at the nanopores at the epoxy/Cu interface. Interfacial bonding energy between the epoxy and copper substrate weakens when water molecules increasingly accumulate at the interface. To verify the simulation results, epoxy was molded on pre-cleaned copper substrate and undergone MSL-1 test. Adhesion strength of the sample set was evaluated by button shear test at different times. They show a strong qualitative correlation between the MSL-1 test data and the MD simulation results. It is concluded that the interfacial moisture diffusion is also an important factor contributing to delamination in plastic packages
{"title":"Effect of Interfacial Adhesion of Copper/Epoxy under Different Moisture Level","authors":"E. Chan, H. Fan, M. Yuen","doi":"10.1109/ESIME.2006.1644046","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644046","url":null,"abstract":"Understanding interfacial adhesion subjected to different levels of moisture content and temperature elevation is of significant interest to the electronic packaging industry. The conventional study has focused primary on moisture diffusion into the encapsulated molding compound (EMC) of plastic packages. This paper looks at the alternative path of interfacial seepage into the EMC and copper interface of the IC package. In this study, the effect of moisture on interfacial bonding energy was calculated by running a molecular dynamics simulation. A series of MD models consisting of a network of epoxy macromolecules and copper atoms with different amount of water molecules at its interface were built with the Discover module. The mass ratio of water molecules to epoxy varied from 1% to 6% while the surrounding temperature kept at 85degC in order to simulate a similar environment condition in MSL-1 qualification test. Calculations were carried out at different humidity level with a prescribed moisture concentration value, using the NVT ensembles. From the simulation results, it is observed that the interfacial bonding energy decreases with the increase of mass ratio of water molecule to the epoxy due to locking of water molecules at the nanopores at the epoxy/Cu interface. Interfacial bonding energy between the epoxy and copper substrate weakens when water molecules increasingly accumulate at the interface. To verify the simulation results, epoxy was molded on pre-cleaned copper substrate and undergone MSL-1 test. Adhesion strength of the sample set was evaluated by button shear test at different times. They show a strong qualitative correlation between the MSL-1 test data and the MD simulation results. It is concluded that the interfacial moisture diffusion is also an important factor contributing to delamination in plastic packages","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"66 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85463625","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 : 2006-04-24DOI: 10.1109/ESIME.2006.1644000
Y.T. He, H.P. Li, F. Li, L. Wang, G.Q. Zhang, L. Ernst
Passivation cracking is one of the main failures of ICs and thermo-mechanical failures are the root cause. A major cause for these failures is due to the different coefficients of thermal expansion (CTE), different Young's modulus, Poisson's ratios of package materials under different temperatures and some mechanical loadings. Therefore the working conditions of compound materials used here is expected to have a pronounced influence on the local stress distribution in the passivation layer. The aeronautical conditions mainly include different temperatures and overloads as well as the vibration conditions. Here the finite element simulations and the maximum principal stress theory are applied to investigate the effects of aeronautical conditions on passivation cracking of microstructures of IC packages, and the result paves the way for compound materials selection in IC packages and usage under aeronautical conditions
{"title":"Effects of aeronautical conditions on passivation cracking of micro-structures of IC packages","authors":"Y.T. He, H.P. Li, F. Li, L. Wang, G.Q. Zhang, L. Ernst","doi":"10.1109/ESIME.2006.1644000","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644000","url":null,"abstract":"Passivation cracking is one of the main failures of ICs and thermo-mechanical failures are the root cause. A major cause for these failures is due to the different coefficients of thermal expansion (CTE), different Young's modulus, Poisson's ratios of package materials under different temperatures and some mechanical loadings. Therefore the working conditions of compound materials used here is expected to have a pronounced influence on the local stress distribution in the passivation layer. The aeronautical conditions mainly include different temperatures and overloads as well as the vibration conditions. Here the finite element simulations and the maximum principal stress theory are applied to investigate the effects of aeronautical conditions on passivation cracking of microstructures of IC packages, and the result paves the way for compound materials selection in IC packages and usage under aeronautical conditions","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"19 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82558927","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 : 2006-04-24DOI: 10.1109/ESIME.2006.1643976
S. Deplanque, W. Nuchter, B. Wunderle, R. Schacht, B. Michel
It is necessary to improve the lifetime prediction based on FE-methods of different electronic packages in order to reduce the time and costs of new developments. This paper purposes a method describing the crack propagation of chip on copper substrate solder joints. The chips that were studied are power transistors. They were soldered on copper substrate (NiAu metallization) with two different solder alloys (SnPb eutectic and SAC 305). The chip dimensions and the solder joint thickness have an influence on the lifetime, so that two different chips with two different solder thicknesses were used as test specimens. These were thermally loaded, and the state of the solder joints was regularly checked. Three different kind of methods were used to characterize the damage of solder joints: the scanning acoustic microscope (SAM) detects the crack initiation and propagation; the cross section analysis can validate the results of the scanning acoustic microscope and can show the microstructure changes; and the thermal resistance which is influenced by the damage of the solder joint was measured and correlated to damage. After presenting the results of these investigations, a general FE-method predicting the crack initiation and propagation using the Paris laws is presented
{"title":"Lifetime Prediction of SnPb and SnAgCu Solder Joints of Chips on Copper Substrate Based on Crack Propagation FE-Analysis","authors":"S. Deplanque, W. Nuchter, B. Wunderle, R. Schacht, B. Michel","doi":"10.1109/ESIME.2006.1643976","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643976","url":null,"abstract":"It is necessary to improve the lifetime prediction based on FE-methods of different electronic packages in order to reduce the time and costs of new developments. This paper purposes a method describing the crack propagation of chip on copper substrate solder joints. The chips that were studied are power transistors. They were soldered on copper substrate (NiAu metallization) with two different solder alloys (SnPb eutectic and SAC 305). The chip dimensions and the solder joint thickness have an influence on the lifetime, so that two different chips with two different solder thicknesses were used as test specimens. These were thermally loaded, and the state of the solder joints was regularly checked. Three different kind of methods were used to characterize the damage of solder joints: the scanning acoustic microscope (SAM) detects the crack initiation and propagation; the cross section analysis can validate the results of the scanning acoustic microscope and can show the microstructure changes; and the thermal resistance which is influenced by the damage of the solder joint was measured and correlated to damage. After presenting the results of these investigations, a general FE-method predicting the crack initiation and propagation using the Paris laws is presented","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"306 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75924659","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 : 2006-04-24DOI: 10.1109/ESIME.2006.1644048
S. Michael, M. Katzschmann, S. Hering
A wafer-level testing method is investigated for an early stage of the manufacturing process applied to accelerometers. The approach consists of performing optical measurement of the modal responses of the MEMS structures, and uses this information in an inverse identification algorithm based on a FE model. Device characteristics can be determined by measured modal frequencies which are fed into a model based on the FE simulations. First measurements were done to validate the model and showed a good correlation between simulated and measured modal frequencies
{"title":"Geometric Parameter Identification for Bulk-Micromachined Accelerometer from Modal Frequencies Measurements","authors":"S. Michael, M. Katzschmann, S. Hering","doi":"10.1109/ESIME.2006.1644048","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644048","url":null,"abstract":"A wafer-level testing method is investigated for an early stage of the manufacturing process applied to accelerometers. The approach consists of performing optical measurement of the modal responses of the MEMS structures, and uses this information in an inverse identification algorithm based on a FE model. Device characteristics can be determined by measured modal frequencies which are fed into a model based on the FE simulations. First measurements were done to validate the model and showed a good correlation between simulated and measured modal frequencies","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"30 3 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80995825","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 : 2006-04-24DOI: 10.1109/ESIME.2006.1643979
Jianjun Wang, W. Peng, W. Ren
In this paper, a simulation procedure was established for the fatigue life prediction of transistor assembly system under thermo-mechanical cyclic loading condition. By combining non-linear finite element (FE) methodology and test data, the failure mechanisms of transistor assembly system in response to thermal cyclic loading condition were investigated. Anand material constitutive model was adopted to describe the behavior of solder layers under the thermal loading conditions. The Coffin-Manson model and the damage expressions were used for the solder layers reliability assessment. An average inelastic energy density accumulated in one cycle over the volume of the critical solder layer was characterized as a parameter for the transistor fatigue life prediction. Based on the framework developed, the fatigue life of two transistor structures with and without void was estimated. The numerical work was validated by the available test data. It is found that the FE results have very good match with the experimental results. It is, therefore, shown that the proposed procedure for the fatigue life prediction of transistor assembly system under the thermal shock cyclic loading condition is reliable
{"title":"Power Amplifier (PA) Transistors Fatigue Life Prediction under Thermo-Mechanical Cyclic Loading","authors":"Jianjun Wang, W. Peng, W. Ren","doi":"10.1109/ESIME.2006.1643979","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643979","url":null,"abstract":"In this paper, a simulation procedure was established for the fatigue life prediction of transistor assembly system under thermo-mechanical cyclic loading condition. By combining non-linear finite element (FE) methodology and test data, the failure mechanisms of transistor assembly system in response to thermal cyclic loading condition were investigated. Anand material constitutive model was adopted to describe the behavior of solder layers under the thermal loading conditions. The Coffin-Manson model and the damage expressions were used for the solder layers reliability assessment. An average inelastic energy density accumulated in one cycle over the volume of the critical solder layer was characterized as a parameter for the transistor fatigue life prediction. Based on the framework developed, the fatigue life of two transistor structures with and without void was estimated. The numerical work was validated by the available test data. It is found that the FE results have very good match with the experimental results. It is, therefore, shown that the proposed procedure for the fatigue life prediction of transistor assembly system under the thermal shock cyclic loading condition is reliable","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"197 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81076434","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 : 2006-04-24DOI: 10.1109/ESIME.2006.1644043
G.Q. Zhang, M. Graef, F. van Roosmalen
In the past decades, the main stream of microelectronics progresses is mainly powered by Moore's law, with two focused development arenas, namely, IC miniaturization down to nano dimension, and SoC based system integration. While microelectronics community continues to invent new solutions around the world to keep Moore's law alive, there are ever-increasing awareness, R&D effort and business drivers to push the development and application of "more than Moore" (MtM) that are based upon or derived from silicon technologies but do not scale with Moore's law (with typical examples as RF, Power/HV, sensor/actuator/MEMS, SiP, SSL, etc.). Starting from a short overview about the motivation and activities of Eniac (European Nanoelectronics Initiative Advisory Council), this paper highlights part of the strategic research subjects for the technology domain of "more than Moore"
{"title":"Strategic Research Agenda of \"More than Moore\"","authors":"G.Q. Zhang, M. Graef, F. van Roosmalen","doi":"10.1109/ESIME.2006.1644043","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644043","url":null,"abstract":"In the past decades, the main stream of microelectronics progresses is mainly powered by Moore's law, with two focused development arenas, namely, IC miniaturization down to nano dimension, and SoC based system integration. While microelectronics community continues to invent new solutions around the world to keep Moore's law alive, there are ever-increasing awareness, R&D effort and business drivers to push the development and application of \"more than Moore\" (MtM) that are based upon or derived from silicon technologies but do not scale with Moore's law (with typical examples as RF, Power/HV, sensor/actuator/MEMS, SiP, SSL, etc.). Starting from a short overview about the motivation and activities of Eniac (European Nanoelectronics Initiative Advisory Council), this paper highlights part of the strategic research subjects for the technology domain of \"more than Moore\"","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"67 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86437947","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 : 2006-04-24DOI: 10.1109/ESIME.2006.1643974
M. Gonzalez, G. Van Barel, A. Witvrouw, B. Vandevelde
A predictive model for the deflection and profile of poly-SiGe beams for different thicknesses and geometries was evaluated. This model combines experimental data and finite element analysis (FEA). The structure employed to derivate the stress gradient and to calibrate and test the FEA calculations is a cantilever beam with dimensions of 1 mm length, 100 mum width and 10 mum thickness. The stress gradient of the film is obtained by measuring the deflection of the cantilevers with different etch depths. The deflection of the beam was calculated initially using a 2D plane stress model. The influence of the clamping region on the deflection was studied by using a perfect clamped beam and compared with a beam clamped only at the bottom clamp interface. In the second case a "tilt" effect near the anchor was observed due to the average stress in the unreleased thin film. FEM has been successfully applied to calculate the deflection of SiGe cantilever beams. Extra information like the stress distribution after releasing, the effect of Poisson's ratio on the curvature of the beam and the effect of clamping on the deflection was investigated
{"title":"An Analysis of Beam Deflections in Poly-SiGe Cantilevers","authors":"M. Gonzalez, G. Van Barel, A. Witvrouw, B. Vandevelde","doi":"10.1109/ESIME.2006.1643974","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1643974","url":null,"abstract":"A predictive model for the deflection and profile of poly-SiGe beams for different thicknesses and geometries was evaluated. This model combines experimental data and finite element analysis (FEA). The structure employed to derivate the stress gradient and to calibrate and test the FEA calculations is a cantilever beam with dimensions of 1 mm length, 100 mum width and 10 mum thickness. The stress gradient of the film is obtained by measuring the deflection of the cantilevers with different etch depths. The deflection of the beam was calculated initially using a 2D plane stress model. The influence of the clamping region on the deflection was studied by using a perfect clamped beam and compared with a beam clamped only at the bottom clamp interface. In the second case a \"tilt\" effect near the anchor was observed due to the average stress in the unreleased thin film. FEM has been successfully applied to calculate the deflection of SiGe cantilever beams. Extra information like the stress distribution after releasing, the effect of Poisson's ratio on the curvature of the beam and the effect of clamping on the deflection was investigated","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"47 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84652595","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 : 2006-04-24DOI: 10.1109/ESIME.2006.1644058
D. Elata
In this work systematic approaches for extracting parameters of the static and dynamic response of electrostatic switches are presented. A novel strategy enables accurate and efficient extraction of the static pull-in state of voltage and charge driven actuators. Another strategy enables to extract parameters of the dynamic pull-in while only considering static states of the system
{"title":"Modeling the Electromechanical Response of RF-MEMS Switches","authors":"D. Elata","doi":"10.1109/ESIME.2006.1644058","DOIUrl":"https://doi.org/10.1109/ESIME.2006.1644058","url":null,"abstract":"In this work systematic approaches for extracting parameters of the static and dynamic response of electrostatic switches are presented. A novel strategy enables accurate and efficient extraction of the static pull-in state of voltage and charge driven actuators. Another strategy enables to extract parameters of the dynamic pull-in while only considering static states of the system","PeriodicalId":60796,"journal":{"name":"微纳电子与智能制造","volume":"122 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2006-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88076025","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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