Pub Date : 2008-07-28DOI: 10.1109/ICEPT.2008.4607097
W. Hao, Zhong Cheng, Li Jin, J. Yiming
The electrochemical corrosion behaviors of indium tin oxides (ITO) films were investigated by electrochemical methods in sodium hydroxide solutions. Cyclic voltammetries of ITO films at both anodic and cathodic polarization were carried out. Transmittance spectra, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were used for characterization of the optical transmittance, the corrosion morphology and identification of corrosion product. ITO film remained stable after anodic polarization. In contrast, serious corrosion occurred at cathodic polarization (approximately -1.3 V vs. saturated calomel electrode (SCE)). Meanwhile, optical transmittance decreased greatly. The results showed that some of Sn4+ in the ITO is reduced to the lower metal state in the form of hydroxides of Sn, which attached to the surface.
{"title":"Electrochemical corrosion behaviors of ITO films at anodic and cathodic polarization in sodium hydroxide solution","authors":"W. Hao, Zhong Cheng, Li Jin, J. Yiming","doi":"10.1109/ICEPT.2008.4607097","DOIUrl":"https://doi.org/10.1109/ICEPT.2008.4607097","url":null,"abstract":"The electrochemical corrosion behaviors of indium tin oxides (ITO) films were investigated by electrochemical methods in sodium hydroxide solutions. Cyclic voltammetries of ITO films at both anodic and cathodic polarization were carried out. Transmittance spectra, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were used for characterization of the optical transmittance, the corrosion morphology and identification of corrosion product. ITO film remained stable after anodic polarization. In contrast, serious corrosion occurred at cathodic polarization (approximately -1.3 V vs. saturated calomel electrode (SCE)). Meanwhile, optical transmittance decreased greatly. The results showed that some of Sn4+ in the ITO is reduced to the lower metal state in the form of hydroxides of Sn, which attached to the surface.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82651769","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 : 2008-07-28DOI: 10.1109/ICEPT.2008.4607066
Xiaosong Ma, K. Jansen, L. Ernst, W. V. van Driel, O. van der Sluis, G.Q. Zhang, C. Regard, C. Gautier, H. Frémont
The use of the non-hermetic material for electronic packaging does raise a potential concern, i.e. moisture induced interfacial delamination and pop corning during reflow. Therefore, it is very important we can correctly model the moisture absorption property. In this study, moisture absorption and desorption properties of three kinds of package materials were investigated. Moisture absorption equilibrium weight gain and diffusion coefficient at different temperature and different humidity are characterized. Moisture absorption processes are simulated using a 3D model at conditions according to the moisture sensitivity test levels. Finally moisture absorption is verified by our research carrier.
{"title":"Moisture diffusion model verification of packaging materials","authors":"Xiaosong Ma, K. Jansen, L. Ernst, W. V. van Driel, O. van der Sluis, G.Q. Zhang, C. Regard, C. Gautier, H. Frémont","doi":"10.1109/ICEPT.2008.4607066","DOIUrl":"https://doi.org/10.1109/ICEPT.2008.4607066","url":null,"abstract":"The use of the non-hermetic material for electronic packaging does raise a potential concern, i.e. moisture induced interfacial delamination and pop corning during reflow. Therefore, it is very important we can correctly model the moisture absorption property. In this study, moisture absorption and desorption properties of three kinds of package materials were investigated. Moisture absorption equilibrium weight gain and diffusion coefficient at different temperature and different humidity are characterized. Moisture absorption processes are simulated using a 3D model at conditions according to the moisture sensitivity test levels. Finally moisture absorption is verified by our research carrier.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82836238","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 : 2008-07-28DOI: 10.1109/ICEPT.2008.4607151
L. Hua, H. Hou
PCB board is an important part of electronic and electrical equipment. In place of piling e-wastes, much of heavy metals in PCB boards percolate into soil, air, river etc. which is a great threaten to environment. In order to removal the hazardous materials for WEEE directive, in this paper, a study on enrichment of lead, cadmium ions by multiwalled carbon nanotubes (MWCNTs) as a solid-phase extraction adsorbent was employed. ICP-OES was used to determine the adsorbed concentrations. Some valuable guidelines can be drawn from the following discussions. MWCNTs has proven to be a promising materials for the removal of contaminants owing to its amazing effects of enrichment, the objective content was concentrated about 50-100 fold, and limit of detection (LOD) was 0.5 mugmiddotkg-1 for Pb, 0.2 mugmiddotkg-1 for Cd. The ion exchange or hydrogen binding mechanism can very well explain the heavy metals such as Pb, Cd adsorption onto CNTs. Sorption can be modeled by Freundlich isotherms from which thermodynamic parameters such as free energy change (DeltaG), enthalpy change (DeltaH), and entropy change (DeltaS) can be calculated. DeltaG<0, DeltaS>0 indicated the process to be feasible and spontaneous nature. DeltaH>0 suggested that the process to be an endothermic nature. Enrichment can be influenced by factors as contact time, temperature, pH and initial concentration of adsorbate, etc. Sorption increased with increasing contact time, and temperature, initial concentration of adsorbate. For each of analyte, there is a neutral pH beyond which MWCNTs will be either positively or negatively charged. Desorption studies have shown the applicability to regenerate the CNTs used. The process is economically feasible and easy to carry out. All those add more credits to MWCNTs for removing pollutants from e-wastes, which is meaningful for complying with WEEE directive.
{"title":"Enrichment and removal of heavy metals contained in PCB boards by multiwalled carbon nanotubes for WEEE directive","authors":"L. Hua, H. Hou","doi":"10.1109/ICEPT.2008.4607151","DOIUrl":"https://doi.org/10.1109/ICEPT.2008.4607151","url":null,"abstract":"PCB board is an important part of electronic and electrical equipment. In place of piling e-wastes, much of heavy metals in PCB boards percolate into soil, air, river etc. which is a great threaten to environment. In order to removal the hazardous materials for WEEE directive, in this paper, a study on enrichment of lead, cadmium ions by multiwalled carbon nanotubes (MWCNTs) as a solid-phase extraction adsorbent was employed. ICP-OES was used to determine the adsorbed concentrations. Some valuable guidelines can be drawn from the following discussions. MWCNTs has proven to be a promising materials for the removal of contaminants owing to its amazing effects of enrichment, the objective content was concentrated about 50-100 fold, and limit of detection (LOD) was 0.5 mugmiddotkg-1 for Pb, 0.2 mugmiddotkg-1 for Cd. The ion exchange or hydrogen binding mechanism can very well explain the heavy metals such as Pb, Cd adsorption onto CNTs. Sorption can be modeled by Freundlich isotherms from which thermodynamic parameters such as free energy change (DeltaG), enthalpy change (DeltaH), and entropy change (DeltaS) can be calculated. DeltaG<0, DeltaS>0 indicated the process to be feasible and spontaneous nature. DeltaH>0 suggested that the process to be an endothermic nature. Enrichment can be influenced by factors as contact time, temperature, pH and initial concentration of adsorbate, etc. Sorption increased with increasing contact time, and temperature, initial concentration of adsorbate. For each of analyte, there is a neutral pH beyond which MWCNTs will be either positively or negatively charged. Desorption studies have shown the applicability to regenerate the CNTs used. The process is economically feasible and easy to carry out. All those add more credits to MWCNTs for removing pollutants from e-wastes, which is meaningful for complying with WEEE directive.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82841063","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 : 2008-07-28DOI: 10.1109/ICEPT.2008.4607007
Meihua Xu, Jian Wu, F. Ran, Tiezhu Li
This paper presents a design of low voltage band-gap reference circuit for OLED-on-silicon. In order to make the op-amp working in the high-gain area, the boost technique is used in the amplifier to increase the gate drive ability. The reference source uses first-order temperature compensation design to eliminate the temperature influence to voltage source. Simultaneously, the power dissipation is greatly decrease because the amplifier designed is working in the weak inversion layer. The simulation is conducted in chartered 0.35 um 2-poly 4-metal 3.3 V/18 V high voltage process, and the results show that the proposed design meets the scheduled requirement and realizes the application of source voltage under 1.8 V.
本文提出了一种用于硅基oled的低压带隙参考电路的设计。为了使运放工作在高增益区域，在运放中采用升压技术来提高栅极驱动能力。参考源采用一阶温度补偿设计，消除了温度对电压源的影响。同时，由于设计的放大器工作在弱反转层，大大降低了功耗。在包车的0.35 um 2-聚4-金属3.3 V/18 V高压工艺中进行了仿真，结果表明所提出的设计满足预定要求，实现了源电压在1.8 V以下的应用。
{"title":"Design of a low voltage band-gap reference circuit for OLED-On-Silicon","authors":"Meihua Xu, Jian Wu, F. Ran, Tiezhu Li","doi":"10.1109/ICEPT.2008.4607007","DOIUrl":"https://doi.org/10.1109/ICEPT.2008.4607007","url":null,"abstract":"This paper presents a design of low voltage band-gap reference circuit for OLED-on-silicon. In order to make the op-amp working in the high-gain area, the boost technique is used in the amplifier to increase the gate drive ability. The reference source uses first-order temperature compensation design to eliminate the temperature influence to voltage source. Simultaneously, the power dissipation is greatly decrease because the amplifier designed is working in the weak inversion layer. The simulation is conducted in chartered 0.35 um 2-poly 4-metal 3.3 V/18 V high voltage process, and the results show that the proposed design meets the scheduled requirement and realizes the application of source voltage under 1.8 V.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82842515","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 : 2008-07-28DOI: 10.1109/ICEPT.2008.4606985
Wei Sun, W.H. Zhu, K.S. Le, H. Tan
PoP is a potential solution to high-speed memory packaging. For PoP package, warpage is known as a concern over package stacking and SMT yield. The PoP package under current study has these features such as fine pitch which is 0.5 mm for both top and bottom, small ball size and that most solder balls are located at the packagepsilas two longer edges. Therefore the solder joint reliability (SJR) in temperature cycling on board (TCoB) test may also pose a concern. The current paper talks about the systematic simulation and optimization of warpage and TCoB SJR for DRAM PoP package. For warpage study, 3D finite element analysis (FEA) was performed. Not only room temperature warpage, but also reflow temperature warpage was investigated. Full factorial DOE analysis with approximation model determination was conducted for both material selection and structural optimization. Based on this study, material selection and layout design guidelines were quickly derived to optimize the warpage performance of this package. In SJR simulation study, various package and stacking configurations were proposed and simulated in an effort to improve the SJR in TCoB test. Suggestions for improvements were made based on those simulation results.
{"title":"Simulation study on the warpage behavior and board-level temperature cycling reliability of PoP potentially for high-speed memory packaging","authors":"Wei Sun, W.H. Zhu, K.S. Le, H. Tan","doi":"10.1109/ICEPT.2008.4606985","DOIUrl":"https://doi.org/10.1109/ICEPT.2008.4606985","url":null,"abstract":"PoP is a potential solution to high-speed memory packaging. For PoP package, warpage is known as a concern over package stacking and SMT yield. The PoP package under current study has these features such as fine pitch which is 0.5 mm for both top and bottom, small ball size and that most solder balls are located at the packagepsilas two longer edges. Therefore the solder joint reliability (SJR) in temperature cycling on board (TCoB) test may also pose a concern. The current paper talks about the systematic simulation and optimization of warpage and TCoB SJR for DRAM PoP package. For warpage study, 3D finite element analysis (FEA) was performed. Not only room temperature warpage, but also reflow temperature warpage was investigated. Full factorial DOE analysis with approximation model determination was conducted for both material selection and structural optimization. Based on this study, material selection and layout design guidelines were quickly derived to optimize the warpage performance of this package. In SJR simulation study, various package and stacking configurations were proposed and simulated in an effort to improve the SJR in TCoB test. Suggestions for improvements were made based on those simulation results.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77238970","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 : 2008-07-28DOI: 10.1109/ICEPT.2008.4607093
Q. Zeng, Jianjun Guo, Xiaolong Gu, Xinbing Zhao
Sn-Sb alloys are potential solders for replacement of high-Pb solders because of their high melting temperature in lead-free solders. However, Cu substrate is extremely dissolved by the Sn-Sb binary alloy during the high temperature soldering process, which will cause serious reliability problem of the solder joint. Based on this critical issue, we designed a new high temperature lead-free Sn-10Sn-5Cu ternary solder to prevent the dissolution of Cu substrate. In this study, liquid-state interfacial reaction between the high temperature lead-free solder and the Cu substrate was investigated. The liquid-state interfacial reaction of the solder on the Cu substrate was carried out at the different temperature of 280degC, 320degC,360degC and 400degC, and the reaction time was 1min, 10mins, 30mins and 60mins, respectively. Microstructure of the Sn-Sb-Cu bulk solder and the solder joint was observed by scattered electron microscope (SEM). The identification of phase composition was determined by Energy Dispersive X-ray Detector (EDX) and electron probe microscopy analysis (EPMA). During the four reaction temperatures, the interfacial reaction products included a scallop Cu6Sn5 intermetallic compound (IMC) layer and a flat Cu3Sn layer adjacent to Cu substrate. IMCs thickness with the reaction time was measured by the area of interface IMCs layer divided by the interface length. The IMCs thickness increased with the reaction temperature and reaction time, and the relationship between IMC thickness and reaction time was linear with square root of time, which signified that the IMC growth dynamics was diffusion controlled. The diffusion coefficient was calculated by the IMC growth rate, which increased with the higher temperature, corresponding to be 2.30 times 10-14, 6.84 times 10-14, 1.63 times 10-13, 1.99 times 10-13 m2/s for the temperatures of 280degC, 320degC, 360degC and 400degC, respectively. And then the diffusion activation energy was determined to be 57.8 KJ/mol by fitting the four diffusion coefficients at various temperatures, which indicated that the diffusion mechanism was grain boundary diffusion. Between lower temperature of 280degC and higher temperature of 400degC, huge differences existed on the microstructure of IMC in the interior solder of the solder joint.
{"title":"Liquid-state interfacial reaction of Sn-10Sb-5Cu high temperature lead-free solder and Cu substrate","authors":"Q. Zeng, Jianjun Guo, Xiaolong Gu, Xinbing Zhao","doi":"10.1109/ICEPT.2008.4607093","DOIUrl":"https://doi.org/10.1109/ICEPT.2008.4607093","url":null,"abstract":"Sn-Sb alloys are potential solders for replacement of high-Pb solders because of their high melting temperature in lead-free solders. However, Cu substrate is extremely dissolved by the Sn-Sb binary alloy during the high temperature soldering process, which will cause serious reliability problem of the solder joint. Based on this critical issue, we designed a new high temperature lead-free Sn-10Sn-5Cu ternary solder to prevent the dissolution of Cu substrate. In this study, liquid-state interfacial reaction between the high temperature lead-free solder and the Cu substrate was investigated. The liquid-state interfacial reaction of the solder on the Cu substrate was carried out at the different temperature of 280degC, 320degC,360degC and 400degC, and the reaction time was 1min, 10mins, 30mins and 60mins, respectively. Microstructure of the Sn-Sb-Cu bulk solder and the solder joint was observed by scattered electron microscope (SEM). The identification of phase composition was determined by Energy Dispersive X-ray Detector (EDX) and electron probe microscopy analysis (EPMA). During the four reaction temperatures, the interfacial reaction products included a scallop Cu6Sn5 intermetallic compound (IMC) layer and a flat Cu3Sn layer adjacent to Cu substrate. IMCs thickness with the reaction time was measured by the area of interface IMCs layer divided by the interface length. The IMCs thickness increased with the reaction temperature and reaction time, and the relationship between IMC thickness and reaction time was linear with square root of time, which signified that the IMC growth dynamics was diffusion controlled. The diffusion coefficient was calculated by the IMC growth rate, which increased with the higher temperature, corresponding to be 2.30 times 10-14, 6.84 times 10-14, 1.63 times 10-13, 1.99 times 10-13 m2/s for the temperatures of 280degC, 320degC, 360degC and 400degC, respectively. And then the diffusion activation energy was determined to be 57.8 KJ/mol by fitting the four diffusion coefficients at various temperatures, which indicated that the diffusion mechanism was grain boundary diffusion. Between lower temperature of 280degC and higher temperature of 400degC, huge differences existed on the microstructure of IMC in the interior solder of the solder joint.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83942330","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 : 2008-07-28DOI: 10.1109/ICEPT.2008.4607096
Xiaoyan Li, Xiaohua Yang, Fenghui Li
The reliability of lead free electronic devices depends strongly on the reliability of the soldered joints while the later one was controlled, mainly, by the formation and growth of the interfacial intermetallic compounds (IMCs) between the solder matrix and the substrates. The morphological features, microstructural evolutions and growth kinetics of the IMCs on the interfacial of SnAgCu/Cu soldered joints, under as soldered and isothermal aging condition, were investigated. The three-dimensional IMCs feature was explored by etch the solder matrix out of the SnAgCu/Cu interface. The phases of IMCs were identified by energy dispersive X-ray (EDX). The thickness of the IMCs was measured by element mapping and phase constitution analysis. The SnAgCu/Cu soldered joints were isothermal aged at 125C, 150C and 175C respectively. The corresponding IMCs growth rate was formulated according to the data from various aging time. The growth kinetic of the IMCs was analyzed in the framework of diffusion principles. The tensile strength of the joint was evaluated by in-situ tensile test and the fracture mechanism was analyzed in accordingly. It was found that Cu6Sn5 was formed at the solder and Cu interface during reflowing. With the increase of aging time, the grain size of the interfacial Cu6Sn5 increased and its morphology was changed from scallop-like to needle-like and then to rod-like and finally to particles. The rod-like Ag3Sn phase was formed at the interface of solder and Cu6Sn5 layer with the increase of the aging time. The growth of the IMCs was found follows Arrheniuspsilas diffusion model and the corresponding diffusion factor and active energy were obtained by data fitting. The IMCs growth rate was found increases with the increase of the aging temperature. The fracture site of the soldered joints was changed from the solder matrix to the interfacial Cu6Sn5 layer with the increase of the aging time.
{"title":"Effect of isothermal aging on interfacial IMC growth and fracture behavior of SnAgCu/Cu soldered joints","authors":"Xiaoyan Li, Xiaohua Yang, Fenghui Li","doi":"10.1109/ICEPT.2008.4607096","DOIUrl":"https://doi.org/10.1109/ICEPT.2008.4607096","url":null,"abstract":"The reliability of lead free electronic devices depends strongly on the reliability of the soldered joints while the later one was controlled, mainly, by the formation and growth of the interfacial intermetallic compounds (IMCs) between the solder matrix and the substrates. The morphological features, microstructural evolutions and growth kinetics of the IMCs on the interfacial of SnAgCu/Cu soldered joints, under as soldered and isothermal aging condition, were investigated. The three-dimensional IMCs feature was explored by etch the solder matrix out of the SnAgCu/Cu interface. The phases of IMCs were identified by energy dispersive X-ray (EDX). The thickness of the IMCs was measured by element mapping and phase constitution analysis. The SnAgCu/Cu soldered joints were isothermal aged at 125C, 150C and 175C respectively. The corresponding IMCs growth rate was formulated according to the data from various aging time. The growth kinetic of the IMCs was analyzed in the framework of diffusion principles. The tensile strength of the joint was evaluated by in-situ tensile test and the fracture mechanism was analyzed in accordingly. It was found that Cu6Sn5 was formed at the solder and Cu interface during reflowing. With the increase of aging time, the grain size of the interfacial Cu6Sn5 increased and its morphology was changed from scallop-like to needle-like and then to rod-like and finally to particles. The rod-like Ag3Sn phase was formed at the interface of solder and Cu6Sn5 layer with the increase of the aging time. The growth of the IMCs was found follows Arrheniuspsilas diffusion model and the corresponding diffusion factor and active energy were obtained by data fitting. The IMCs growth rate was found increases with the increase of the aging temperature. The fracture site of the soldered joints was changed from the solder matrix to the interfacial Cu6Sn5 layer with the increase of the aging time.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75962940","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 : 2008-07-28DOI: 10.1109/ICEPT.2008.4607134
Minhua Lu, D. Shih, P. Lauro
Electromigration (EM)-induced damage in lead-free solders strongly depend on the Sn grain orientation in the Pb-free solder joint. Significant damage can develop at a very early stage when the c-axis of a Sn-grain is oriented close to the current direction. Rapid dissolution of both intermetallic compounds (IMC) and under-bump metallurgy (UBM) that led to significant cavitations at interface is caused by fast diffusion of Cu and Ni through the Sn crystal along the c-axis. On the other hand, when the c-axis of a Sn grain is not aligned with the current direction, cavitations at solder-IMC interface are formed mostly due to Sn-self diffusion which is correlated with failures at a much longer stress time. This is a direct proof of the highly anisotropic diffusion behavior of Cu and Ni in Sn, reported by Turnbull and Huntington many years ago. The stable Ag3Sn network and cyclic twinning in SnAg solder contributed to the better EM performance of Sn1.8Ag compared to that of Sn0.7Cu solder. The ranking of the three surface finishes, from best to worst, is Ni(P)/Cu, Ni(P)/Au, and Cu, when electrons are entering from the tested surfaces. A Ni barrier layer is needed to retard the electromigration damage. However, the addition of Cu at an optimized level to the Sn-Ag solder drastically improved the electromigration performance.
{"title":"Electromigration in Pb-free solders","authors":"Minhua Lu, D. Shih, P. Lauro","doi":"10.1109/ICEPT.2008.4607134","DOIUrl":"https://doi.org/10.1109/ICEPT.2008.4607134","url":null,"abstract":"Electromigration (EM)-induced damage in lead-free solders strongly depend on the Sn grain orientation in the Pb-free solder joint. Significant damage can develop at a very early stage when the c-axis of a Sn-grain is oriented close to the current direction. Rapid dissolution of both intermetallic compounds (IMC) and under-bump metallurgy (UBM) that led to significant cavitations at interface is caused by fast diffusion of Cu and Ni through the Sn crystal along the c-axis. On the other hand, when the c-axis of a Sn grain is not aligned with the current direction, cavitations at solder-IMC interface are formed mostly due to Sn-self diffusion which is correlated with failures at a much longer stress time. This is a direct proof of the highly anisotropic diffusion behavior of Cu and Ni in Sn, reported by Turnbull and Huntington many years ago. The stable Ag3Sn network and cyclic twinning in SnAg solder contributed to the better EM performance of Sn1.8Ag compared to that of Sn0.7Cu solder. The ranking of the three surface finishes, from best to worst, is Ni(P)/Cu, Ni(P)/Au, and Cu, when electrons are entering from the tested surfaces. A Ni barrier layer is needed to retard the electromigration damage. However, the addition of Cu at an optimized level to the Sn-Ag solder drastically improved the electromigration performance.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76224610","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 : 2008-07-28DOI: 10.1109/ICEPT.2008.4606979
Xi-chuan Wang, Bin-feng Qian
Multi-core processor is widely used on the server and desktop computer nowadays. This paper describes the structure of a cache crossbar which used in the multi-core processor SPARC T2. The cores can use the cache crossbar to exchange the data in the L2 cache banks. The multi cores can communicate among each other core by sharing the data in the L2 cache banks. And with the analysis of the CCX, this paper provides a protocol for connecting multi cores and cache banks. The cache crossbar is implemented in SMIC 0.13 mum with design compiler and can run at 200 MHz.
{"title":"The design of the cache crossbar based on OpenSPRAC architecture","authors":"Xi-chuan Wang, Bin-feng Qian","doi":"10.1109/ICEPT.2008.4606979","DOIUrl":"https://doi.org/10.1109/ICEPT.2008.4606979","url":null,"abstract":"Multi-core processor is widely used on the server and desktop computer nowadays. This paper describes the structure of a cache crossbar which used in the multi-core processor SPARC T2. The cores can use the cache crossbar to exchange the data in the L2 cache banks. The multi cores can communicate among each other core by sharing the data in the L2 cache banks. And with the analysis of the CCX, this paper provides a protocol for connecting multi cores and cache banks. The cache crossbar is implemented in SMIC 0.13 mum with design compiler and can run at 200 MHz.","PeriodicalId":6324,"journal":{"name":"2008 International Conference on Electronic Packaging Technology & High Density Packaging","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73641269","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 : 2008-07-28DOI: 10.1109/ICEPT.2008.4606940
Y. Lv, L. Wan
ZnO as an excellent candidate for UV light emitters, varistors, transparent high-power electronics, surface acoustic wave devices, piezoelectric transducers, and chemical and gas sensors could be integrated in a SiP (system-in-package). The SiP could be a critical part in sensor nodes in a sensor network. Normally, the ZnO device in SiP is fabricated with nanoscale films which can be compatible with other materials and processing in a package. However, despite the great potential for electron and photonic applications, ZnO device fabrication is difficult to obtain good ohmic contact. The low resistance and thermal stable ohmic contacts is critical to realize high-performance ZnO-based devices. In this paper, the recent advances of ohmic contacts on ZnO are analyzed and reviewed. The mechanism of the energy band bending at the interface of the semiconductor and the metal is discussed. The factors of forming good quality ZnO films such as the choice of the substrate and the method to deposit ZnO film, the effect of the contact resistance and thermal stability of ohmic contacts are summarized.
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