2015 16th International Conference on Electronic Packaging Technology (ICEPT)最新文献

{"title":"Interfacial reactions and formation of intermetallic compound of Sn-ball/Sn-3.0Ag-0.5Cu-paste/Cu joints in flip-chip on BGA packaging","authors":"Jia-Qiang Huang, Min-bo Zhou, Wang-yun Li, Xin-Ping Zhang","doi":"10.1109/ICEPT.2015.7236598","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236598","url":null,"abstract":"The interfacial reactions and formation of intermetallic compound of Sn-ball/Sn-3.0Ag-0.5Cu-paste/Cu joints in flip-chip on BGA packaging were studied by using a differential scanning calorimeter. Results show that a thin circular Cu₆Sn₅ layer forms first on the surface of Cu substrate due to the diffusion of Sn atoms dissolved in the soldering flux, subsequently the planar-like Cu₆Sn₅ layer forms and covers over the first layer, and many Ag₃Sn particles form in the grain boundaries of Cu₆Sn₅. Then, a slight increase of the soldering temperature from 217°C to 218°C has a significant influence on the morphologies of the interfacial Cu₆Sn₅ and Ag₃Sn, that is, the morphologies of Cu₆Sn₅ and Ag₃Sn are changed into scallop-like and large plate-like, respectively. When the soldering temperature is increased to 221°C, a large amount of plate-like Ag₃Sn phase dissolves into the molten solder and the small network-like Ag₃Sn phase forms, and the grain size of Cu₆Sn₅ is increased. Furthermore, there is almost no trace of Ag₃Sn at the interface layer of Cu₆Sn₅ at the soldering temperature of 227°C. The morphology changes of the interfacial Cu₆Sn₅ and Ag₃Sn are attributed to the increase of interfacial energy and the eutectic reaction between Sn and Ag in the solder matrix, respectively.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128225217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure design of through silicon via interconnects and growth of carbon nanotubes","authors":"Dongfang Xu, Zheyao Wang","doi":"10.1109/ICEPT.2015.7236774","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236774","url":null,"abstract":"In this paper, we design a new program to achieve carbon nanotubes through silicon vias (TSV) interconnects compatible with CMOS technology using an auxiliary TSV structures and laser local heating method. Auxiliary TSV structures are made by two wafers. One wafer is etched into ups and downs structures and then deposited SiNx and SiO2 film. The other one is made into TSV structures by deep silicon etching, depositing thin film and wafer thinning and polish. Two wafers are bonded together by patterned BCB (Benzocyclobutene). For the entire device structures, we use FDTD solutions software to simulate infrared optical properties of SiNx. SiNx film layer can absorb 10.6 μm infrared laser strongly. Thermal simulation of geometrical model by COMSOL Multiphysics software shows well temperature compatibility. It turns out the program is compatible with current CMOS processes. Using a laser local heating method, we have studied the local growth of carbon nanotubes. Carbon nanotubes grown in TSVs are sparse, intertwined and have a poor morphology; the reason for this is that TSVs' geometric sizes limit gases flows. Carbon nanotubes interconnect still need further study.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129019389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The finite element simulation and nanoindentation methods for the study of mechanical behavior of lead-free solder joints","authors":"Lifeng Wang, Jia Zhou, Yingjie Liu, Q. Ge, Yuanjian Zhang, Wenqin Dai","doi":"10.1109/ICEPT.2015.7236582","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236582","url":null,"abstract":"Nanoindentation experiment together with the finite element simulation was used to study the mechanical behavior of Sn3.0Ag0.5Cu (SAC305) lead-free solder joint under cyclic loading-unloading. The effect of different maximum loads and holding time on the micromechanics behavior was investigated. The results indicated that the increase of the maximum load caused the increase of the depth of residual indentation and the area of hysteresis loop. The creep displacement of solder joint was increased with the prolonging of holding time. It increased sharply at first, and then went stabilized. In addition, a good agreement between finite element model and experimental results was reached.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114554549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of copper electroplating fill process with different parameters for through silicon via","authors":"Junlin Liu, Fuliang Wang","doi":"10.1109/ICEPT.2015.7236742","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236742","url":null,"abstract":"Copper electrodeposition of through silicon via(TSV) is one of the technical challenges for 3D integration, and parameters that impact on a high aspect ratio TSV filling are various. A numerical model of TSV filling which is based on different parameters is established to simulate the copper plating process in TSV. The flux, current density and shape evolution during copper deposition process are obtained through the numerical model with a commercial software, and the impact on the filling mechanism of three plating parameters- concentration, diffusion coefficient, and electrode potential - have been investigated by comparing the void area of deposition with different parameters. We found that the effects of concentration and diffusion coefficient on TSV filling were similar, and the increasing concentration or diffusion coefficient led to a better filling; the reducing electrode potential is beneficial to fill. Thus a guideline for optimizing the filling of a high aspect ratio TSV was provided.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"190 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116504532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular modeling design of polyaniline as carbon dioxide sensor","authors":"Q. Liang, Junke Jiang, Xiang Sun, M. Cai, Yiping Huang, Daoguo Yang, Xianping Chen, T. Ren","doi":"10.1109/ICEPT.2015.7236563","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236563","url":null,"abstract":"Polyaniline (PANI) is a most promising material for sensing due to its straightforward preparation procedure, high chemical, environmental stabilities and low cost. The ability of PANI to interact with H2O and CO2 with concomitant changes in the electronic and geometric properties of PANI makes it as potential sensor for CO2. Detection and monitoring of CO2 by quantum mechanical studies have been devoted to examine the sensitivity and selectivity of PANI at the molecular level. From quantum mechanics to explain the CO2 adsorption is quite important because CO2 in the greenhouse can be detrimental for plant growth and consequently productivity. Compared with traditional industrial sensors, polymer-based sensors for the agricultural exhibit several advantages such as working under extreme temperatures, pressures, and complex environment. However, the poor solubility of PANI and low chemical reactivity restricts its widespread application to a great extent. Introducing functional groups in PANI backbone is an effective method to improve the solubility, chemical reactivity and sensitivity of PANI, this method can increase the sensing properties of PANI and do not strongly impact the conductivity. Therefore, measurements of the adsorption energy and charge transfer for H2O and CO2 in emeraldine base PANI (EB-PANI) and undoped sodium sulfonated PANI (Na-SPANI) using first principles methods were investigated. Doping could greatly changing the sensing mechanism of conducting polymer, so not only the adsorption sites but also the functional group affecting the gas sensitive performance were studied. The adsorption energy and Mulliken charge analysis were obtained for EB-PANI and Na-SPANI to evaluate the sensing ability of them for analytes. Besides, we also combined molecular dynamics to calculate mean square displacement of CO2 in EB-PANI and Na-SPANI. We concluded that Na-SPANI has greater response toward H2O and CO2 than EB-PANI. So Na-SPANI can be used as sensing material for CO2 detection. This study provides a rational way using first principle simulation to evaluate and design PANI for the application of carbon dioxide sensor.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131360010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Failure analysis on bad wetting of ENIG surface finish pads","authors":"Weiming Li","doi":"10.1109/ICEPT.2015.7236644","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236644","url":null,"abstract":"Electroless nickel/immersion gold (ENIG) is an effective surface finish, which guarantees good corrosion resistance, a long shelf life, a flat soldering surface for surface mount technology (SMT) and a good electrical probe surface for in-circuit-test. ENIG has become a popular surface finish for pads of printed circuit boards (PCB) and ball grid array packages (BGA). However, the disadvantages of ENIG surface finish pads cannot be neglected. Compared with other surface finishes, such as organic surface protection (OSP) and hot air solder leveling (HASL), ENIG is always more expensive. Except for the high cost, another significant disadvantage of ENIG surface finish pads is related to the so called “black pad”, which may lead to bad wetting, including nonwetting and dewetting, as well as brittle solder joints. In this paper, the failure analysis on bad wetting of ENIG surface finish pads related to “black pad” is revealed with the aid of optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray photoelectric spectroscopy (XPS). Surface of bad wetting solder joints and nickel layer of bare PCB pads was analyzed with OM and SEM/EDS. The bad wetting area of the joints showed black through the inspection of OM. The result of SEM/EDS demonstrated that typical \"black pad\" morphology of nickel layer with \"mud crack\" appearance was found on the surface of both the bad wetting area of the solder joints and the nickel layer of bare PCB pads. Depth profiling analysis was performed on the bare PCB pad with XPS. The curve of phosphorus content showed a peak during the profiling process, which indicated a phosphorus rich layer in the gold/nickel coating. The phosphorus rich layer was resulted from the consumption and corrosion of nickel during the immersion gold plating process. Metallographic specimens of the bad wetting solder joint and the bare PCB pad were prepared and the cross sections were analyzed with SEM. Continuous IMC was formed at the interface between the PCB pad and solder. The thicknesses ofIMC layer of the solder joint at the pad side and at the component side were -0.3-0.7 J.1m and -1.8 J.1m, respectively, which are within a reasonable range. It indicates that the bad wetting was irrelevant to parameters during the soldering process. Spikes of the nickel layer were observed in the cross section of the bare PCB pad, which are in accordance to the \"mud crack\" morphology of black pad. The severe \"black pad\" defect degraded the solderability of the PCB pads, leading to the bad wetting of the solder joints eventually. Solderability test was performed on the bare PCB following the procedures of J-STD-003B, Test C1. Bad wetting and black pads were found after the solderability test as well, from which it can be inferred that the bad wetting was mainly related to the weak solderability of PCB pads and the \"black pad\" defect degraded the solderability of ENIG surface finish pads.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130130625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface characterization and electrical properties of spin- coated graphene conductive film","authors":"Weijun Zhang, Ming Li, Liming Gao, Xiaolei Ban","doi":"10.1109/ICEPT.2015.7236544","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236544","url":null,"abstract":"The Excellent printability of graphene sheets on large scale, flexible substrates makes graphene a perfect substitute of traditional conductive material in electronics industry. In this letter we demonstrate several properties of conductive film prepared by spin-coating graphene on PET substrates. After spin coating and air dry, the graphene film had a sheet resistance of 47.4Ω/□, resistivity of 1.07 mΩ·m. With a subsequent heating at 70°C, the resistivity was reduced to 0.18mΩ·m due to more outgassed liquidous solution and better contact of graphene nanoplatelet. Multilayer films were also prepared, and the graphene resistivity and microstructure versus film thickness was investigated. It is observed that the electric resistance declines as the film thickness increases. The thick film resulted in less-rough surface according to Scanning Electronic Microscope (SEM) and Atomic Force Microscope (AFM) inspection.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130818490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Creep behaviors of Pb-free solder joints during current stressing","authors":"Y. Zuo, Limin Ma, F. Guo, H. Ding","doi":"10.1109/ICEPT.2015.7236691","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236691","url":null,"abstract":"Electromigration and creep as two of the most important reliability issues gain much attention, and flurry of academic activities dedicate to understand fundamental physics of them. However, since real solder joints are usually exposure to complicated conditions with high current density, temperature excursion, and mechanical loading, when analyzing creep of a real solder joint, Electromigration must be taken into account because of the interaction between them. In this study, simple shear to failure was performed at different temperature and stress level to evaluate failure behavior of solder joints. Activation energy and stress exponent under high current density were also calculated and discussed. This research indicated that, strain rate was accelerated by high current density at different levels of stress and temperature. The effect of high current density played more important roles at low stress and low temperature condition. At high stress and high temperature, the accelerating effect was not that significance. When high current density was introduced, both activation energy and stress exponent tend to decrease.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130819330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PSO based on chaotic map and its application to PID controller self-tuning","authors":"X. Dai, Zhili Long, Jianguo Zhang","doi":"10.1109/ICEPT.2015.7236860","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236860","url":null,"abstract":"As a kind of iterative learning algorithm, PSO algorithm is analogous to the stochastic behaviors of creatures in nature for foraging such as birds and fish, through self-learning strategies and synergy of swarm to determine their searching directions. In order to strengthen diversity and searching ergodicity of particles, this paper proposed an initial method of adaptive inertia weight based on chaotic map and proved the swarm's convergence is prior to stochastic initialization by embedding in three common improved PSOs with test of three benchmark functions. The proposed algorithm is applied to self-turn a PID controller which is widely used in precise positioning realms such as electronic packing technology subsequently. The outperformed performance of MSPO based on chaotic map is calculated and verified by simulated results.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131007496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas adsorption on graphene with different layers: A first-principles study","authors":"Jiaming Ni, N. Yang, Q. Liang, Junke Jiang, R. Meng, Yiping Huang, Xianping Chen","doi":"10.1109/ICEPT.2015.7236745","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236745","url":null,"abstract":"At present, the sensor is widely used and its types are varied, such as biosensor, gas sensor, humidity sensor, optics sensor, pressure sensor, etc. However, many defects of sensors remain to be optimized in many aspects such as conductivity, stability and adsorption capacity. According to the performance of materials, the study of the adsorption behavior of H2, CO2, CH4, Ar and N2 on the pristine graphene has been performed through First-principle calculation. The graphene has been attracted popular attention all over the world, because the two-dimensional crystal structure of graphene has a good mechanical, electrical properties etc. The graphene also has a great specific surface area, so it has a well adsorption capacity. The graphene is a zero-n gap semiconductor with no magnetism, however, the graphene will be magnetic if it adsorbed or doped with other materials even the band gap is opened. Therefore, the graphene has a promising future in nano electronic devices such as gas sensor. We compared the electronic structures and the magnetism between the pristine graphene and the gas molecule-adsorbed graphene through the first principle calculation. We have found that the different types of graphene have different electronic band structures. Most of the molecules adsorption on graphene can be weakly charged took as donor or acceptor. We discovered that the band gap and the adsorption energy is different when the gas molecules adsorped on the graphene with different number of layers. The different layers have different impacts on the adsorption of graphene. Therefore, according to First principles calculation, with the number of layers increasing, the gas adsorption property of graphene is getting better and better. This study provides a rational way using first principle simulation to evaluate the different number of layers of graphene for the adsorption of sensors.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124251773","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}