{"title":"Electromigration behavior of Cu-core/Sn-shell solder joints","authors":"Wenkai Mu, Wei Zhou, P. Wu","doi":"10.1109/ISAPM.2011.6105724","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105724","url":null,"abstract":"The electromigration behavior of a solder joint with Cu-core/Sn-shell structure under 1.3×104 A/cm2 was investigated in this work. As Cu has lower electrical resistivity than Sn, the Cu core was chosen primarily as the path for current flux. Compared with the traditional solder joint, this core/shell solder has two couples of cathode and anode due to the additional Cu core. It is found that most morphology changes appeared at the region where current crowding occurred according to finite element simulation. Under electron wind force, some Sn grain at the anodes rotated as a result of stress relaxation and the angle of the rotation increased with prolonging the stressing time. No obvious intermetallic compound growth was found.","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"62 1","pages":"313-317"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89532045","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":"Nano copper conductive ink for RFID application","authors":"Jian Li, B. An, Jian Qin, Yiping Wu","doi":"10.1109/ISAPM.2011.6105678","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105678","url":null,"abstract":"A novel nano copper conductive ink, composed of anti-oxidation nano copper particles and chemical additives, had been successfully developed and employed for RFID application. A pattern of UHF RFID antenna was chosen to print on polyimide (PI) film by ink-jet printing, and then cured by UV light to form the copper wire. The adhesion of the nano copper ink film on PI was checked by cross cut tape test, and the results showed 100% film remained. As the RFID antennas and RF chips were packaged by anisotropic conductive adhesive to form the RFID inlays, the reading distance of the inlays can reach 3 meters. This proved that nano copper conductive ink had a potential for RFID application.","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"4 1","pages":"91-93"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90636687","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":"Effect of hygro-thermo-mechanical stress on reliability of stacked die package","authors":"W. Zhu, P. Lai, Shaohua Yang","doi":"10.1109/ISAPM.2011.6105700","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105700","url":null,"abstract":"Mechanical reliability of epoxy molding compounds in plastic packages of integrated circuits (IC) is greatly affected by the compound ability to absorb moisture. In this paper, the hygro-thermal effect of a 2-layer stacked die package was investigated which emphasized on the hygroscopic stress and thermal mismatch stress. By finite element analysis (FEA), the distribution of moisture diffusion, thermo-mechanical stress, hygro-mechanical stress and hygro-thermo-mechanical stress under hygro-thermal environment were simulated and calculated. The simulation results showed that the bottom die-attach endured higher thermal stress after the moisture preconditioning under 85°C /85% RH. By simulation of hygroscopic swelling stress during reflow process, it was indicated that the critical position for the package reliability located at the corner of the bottom die and the interface between the bottom die-attach and die. Therefore, the reliability of the bottom layers is relatively low under hygro-thermal environment.","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"74 1","pages":"204-208"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73942199","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":"Analysis of reconfigurable antenna with K and Ku wave bands based on RF switch","authors":"Tian Wen-chao, Cao Yanrong, Wang Hongming","doi":"10.1109/ISAPM.2011.6105682","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105682","url":null,"abstract":"A MEMS (Micro-Electro-Mechanical Systems) RF (Radio Frequency) switch with the low loss and high isolation is presented. The model of a reconfigurable patch antenna with K and Ku wave bands is set up. The reconfigurable antenna has two work frequencies by changing the topology structure with the RF switch. The bandwidth is expanded from 1.16% to 7.71% by adding two parasitic patches. The resonance frequencies are 20.1GHz and 12.5GHz, respectively. The gains of K and Ku wave bands are obtained.","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"47 1","pages":"109-111"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79203725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A new package structure with power stacked-die multi-row lead and process flow","authors":"Shunan Qiu, F. Zong, Tian Jiang","doi":"10.1109/ISAPM.2011.6105755","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105755","url":null,"abstract":"SIP (System in Package), enhanced power capability and high I/O count are three technological trends of semiconductor packaging. Power Stacked-die Multi-row Lead package could synthesize these three advanced features into one single package by utilizing the stacked-die structure, Al wires and multi-row leads. The manufacturing process flow consists of twice die bonding, wire bonding, molding and lead trimming and forming processes. This paper will also analyze the potential issues of manufacturing process and propose the corresponding solutions.","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"38 1","pages":"354-359"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85727572","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":"Stress simulation for 2N gold wires and evaluation on the stitch bond shapes","authors":"Weidong Huang, D. Bai, Andy Luo","doi":"10.1109/ISAPM.2011.6105722","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105722","url":null,"abstract":"Finite Element (FE) simulation is an effective approach to investigate the thermal stress status and the reliability trend when qualifying a new packaging material going through the reliability test. However, simulation of thermal stresses in gold wires was rarely reported in previous days due to the hardness in FE model building. This study performs 3D modeling to evaluate the thermal stresses in 2N gold wires with the full package model to identify which wires to peel for process control setup. The results from this modeling will be used to verify the second bond to file the process specification of wire peel test. The FE model in this paper describes a PBGA package with 2N gold wires surrounded by mold compound and other parts of the package. Stress evaluation is done through discussing the Von Mises stress, the equivalent plastic strain and the peeling stress. TC (temperature cycle) condition is applied in the modeling. The simulation results indicate that shorter wire(s) has higher stress than longer wire(s) and shorter corner wire(s) has the highest propensity to fail in TC. Different from the other wires, the highest peeling stress on bonding interface for the shorter center wire(s) is at the wire heel location instead of the tail end of the stitch bond. The wire heel location is usually regarded as the sensitive region related with the initial crack leading to the stitch bond failure. Thus, the shorter corner and center wire(s) should be regarded as high priority to be wire peeled and filed into wire peel specification. Besides, the relationship between stress status (reliability propensity) of stitch bond and the stitch bond shape is discussed. According to the measurement data of various stitch shapes, three typical stitch bond shapes (marked as A, B and C) are proposed and modeled. The modeling data show that the shortest stitch length (shape A) has the highest stress and plastic strain in the stitch bond comparing with the other shapes, and produces the highest peeling stress at bond interface. It might imply that the shortest stitch length could cause the higher propensity leading to bond lift in stress test. It could become a guideline for wire bond process that engineers should avoid forming the short stitch length when bonding 2N gold wires.","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"52 1","pages":"134-140"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90051608","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":"Synthesis and low-temperature sintering of tin-doped silver nanoparticles","authors":"Yujun Zhang, Hui Yu, Liangliang Li","doi":"10.1109/ISAPM.2011.6105702","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105702","url":null,"abstract":"Ag nanoparticles have been widely used in electronic packaging due to their low-temperature sintering properties. It is important to lower the melting point of Ag nanoparticles to achieve a better electrical/thermal conduction and mechanical strength. In this paper, a large amount of Sn-doped Ag nanoparticles with a size less than 10 nm were synthesized and the EDS and XRD data showed that the Sn atoms entered the Ag lattice. The sintering properties of the nanoparticles baked at different temperatures was investigated by SEM and a larger coalescence was observed for the Sn-doped Ag nanoparticles compared to the pure Ag nanoparticles, indicating that Sn helped the sintering of the nanoparticles. TGA and DSC experiments were also carried out to study the sintering process in detail.","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"74 1","pages":"209-212"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80483258","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}
Lifei Lai, R. Sun, T. Zhao, Xiaoliang Zeng, Shuhui Yu
{"title":"Processing technology of embedded thin-film resistor materials","authors":"Lifei Lai, R. Sun, T. Zhao, Xiaoliang Zeng, Shuhui Yu","doi":"10.1109/ISAPM.2011.6105671","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105671","url":null,"abstract":"It is relatively rare for us to research Embedded Thin-Film Resistor (ETFR) Materials in domestic. This paper describes the development history and present situation of the ETFR, the whole process technology is told, the urgency of domestic products is revealed, the thermal stability and microscopic characteristics of the Ni-Cr (80/20 wt.%) ETFR material that we have researched are introduced, the possible development and application is also tentatively discussed.","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"122 1","pages":"60-65"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85260086","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}
S. Ito, T. Ogashiwa, Y. Kanehira, H. Ishida, S. Shoji, J. Mizuno
{"title":"Evaluations of low temperature bonding using Au sub-micron particles for wafer level MEMS packaging","authors":"S. Ito, T. Ogashiwa, Y. Kanehira, H. Ishida, S. Shoji, J. Mizuno","doi":"10.1109/ISAPM.2011.6105749","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105749","url":null,"abstract":"This paper describes wafer level vacuum packaging with sub-micron Au particles for MEMS (micro electro mechanical systems) applications. Low temperature bonding is indispensable for relevant MEMS packaging, and use of sub-micron Au particles are suitable for hermetic seal bonding. For the fabrication of hermetically sealed wafer level packaging, a base silicon wafer and a cap glass wafer were bonded at around 200°C. Before bonding, the surface of seal rings was observed with a laser microscope to investigate the effect of surface roughness for hermeticity. After bonding, bonded wafers were dipped in the hydrofluoroether for 30 min. As a result, surface flatness of Au particles contributed to achieve hermetic sealing. Double seal rings structures were also useful to realize hermetic sealing.","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"64 1","pages":"342-347"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82841323","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 re-evaluation of mechanical properties of wire bonding","authors":"A. Jalar, M. Zulkifli, N. Othman, S. Abdullah","doi":"10.1109/ISAPM.2011.6105705","DOIUrl":"https://doi.org/10.1109/ISAPM.2011.6105705","url":null,"abstract":"Wire bonding is the most popular interconnection technique that has been used in microelectronics packaging due to its maturity and cost effectiveness. The technology advances in the era of miniaturization and multifunction have urges the need for the smaller wire bond size to cope with the decrease of bond pad pitches. Ultimately, this will introduces al lot of technology challenges in the characterization and performance of wire bonding micromechanical properties. The conventional tests such as wire pull and ball shear tests provide inadequate information in respect of bonding and metallurgical response of the interconnection. This is because the evaluations of wire bond performance based on conventional tests are more into qualitative results or failure modes rather than detailed quantitative results. Furthermore, the results obtained through wire pull and ball shear tests will change and introduce a lot of variations as the ball bond diameter become smaller. In the present analysis, nanoindentation test was introduced in order to provide more adequate information about the quality of wire bond. Nanoindentation test provides the micromechanical properties in terms of hardness and reduced modulus value in the small length scale. This will facilitate the micromechanical properties measurement of the wire bond. In addition, the continuous measurement of stiffness provided from nanoindentation test realizes the qualitative results of materials such as deformation, strain hardening effect and creep behaviour. Wire bonding process was prepared using thermosonic wire bonding technology using 25 μm diameter of gold wire on the Aluminium bond pad. The nanoindentation test was conducted at various locations on the ball bond that has been cross-sectioned diagonally prior to the indentation process. To further investigate the micromechanical properties, the location of indentations was divided into two zones namely Zone 1 and Zone 2. Zone 1 is located at the area near to the intermetallic layer of Au and Al, while Zone 2 is located at deformed ball bond created from the inner chamfer of capillary. The results show that the micromechanical properties of ball bond vary throughout the location of indentations. The hardness and the reduced modulus for the indentations that located at the Zone 1 have higher average values compared to that of the indentations that located at the Zone 2. The average value of hardness and reduced modulus for the indentations at the Zone 1 are 1.011 GPa and 88.652 GPa, respectively. While the average value of hardness and reduced modulus for the indentations at the Zone 2 are 0.853 GPa and 70.652 GPa, respectively. In addition, indentation 1 of Zone 1 that located perpendicular to the effect of deformation created from the end of capillary has the highest value of hardness with value of 1.156 GPa. The value of hardness for the indentations 3 and 4 of Zone 1 has the lowest value of hardness with value of 0.928 GPa and 0.834 GPa, re","PeriodicalId":6440,"journal":{"name":"2011 International Symposium on Advanced Packaging Materials (APM)","volume":"12 1","pages":"226-233"},"PeriodicalIF":0.0,"publicationDate":"2011-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76755149","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}