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

{"title":"Effect of magnetic particles on the microstructure and wettability of Sn-Zn lead-free solders","authors":"Yao Yao, Zhou Jian, Xueyuan Feng, Chen Xu","doi":"10.1109/ICEPT.2015.7236787","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236787","url":null,"abstract":"Sn-Zn solder has gained much attention because of its low soldering temperature, excellent mechanical properties and low-cost. However, there are two main problems that restrict its applications, poor wettability and poor oxidation resistance. To improve the wettability of the Sn-Zn solders, magnetic particles (Fe and Ni) were added into the alloys. The microstructure and interfacial reaction were examined by backscatter electron microscopy (BSE) and the phases were identified by energy-dispersive spectroscopy (EDS). The results indicated that the Fe particles were mainly distributed in the surface of solder and intermetallic (IMC) was not observed at the interface between Fe particles and solder matrix. However, the Ni particles were distributed in the solder matrix uniformly and the Ni-Zn IMC was formed at the interface between Ni and solder. The wettability of these composites were also investigated in this paper. The results of wettability tests showed that the wettability noticeably improved after adding the magnetic particles. With vertically down and move magnetic field, the wetting angle decreased from 64.9 to 8.7 and 15.2 for Fe and Ni, respectively, when the mass fraction of magnetic particles increased from 0 to 6%.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"353 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":"131701363","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":"Optical performance enhancement of light-emitting diodes with quantum dots through new remote type structure","authors":"Xiang Lei, Huai Zheng, Peizhao Liu, Xing Guo, J. Chu, Ying Zhou, Sheng Liu","doi":"10.1109/ICEPT.2015.7236724","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236724","url":null,"abstract":"Nowadays colloidal quantum dots (QDs) have been developed as a promising light-converting material for light-emitting diodes (LEDs). However, QDs-based LEDs always show saturation effect at high forward current. In this paper, a new remote packaging structure was proposed to reduce the saturation effect and utilize the QDs fully. The comparison of optical performance between proposed remote structure and current structures, flat structure and air-gap with regular lens was conducted through experiments. The luminous efficiencies of air-gap structure with regular lens and proposed remote structure are over 22% higher than flat structure at the driving current of 20mA. With the current increasing from 20 to 800mA, the luminous efficiencies of flat structure and air-gap structure with regular lens decrease by 66.5% and 61.5%, respectively. While the proposed remote structure shows the luminous efficiency decrease of 37.7%. Therefore, at the driving current of 800mA, compared to current structures, the proposed remote structure increases the luminous flux by 70.5% and 50.1%, respectively. The experimental results demonstrate that the new packaging structure have large advantages in terms of the luminous efficiency and the stability.","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":"130618771","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 on thermo-mechanical reliability of TSV interposer and solder joint","authors":"Xuelong Tong, Zhu Yuan, Ming Xue-fei, Zhan Guohua","doi":"10.1109/ICEPT.2015.7236562","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236562","url":null,"abstract":"TSV interpsoer is one of the common forms used the 3D package. In this paper, the 3D finite element method is used to analyze the thermo-mechanical reliability of TSV interposer and solder joint. This paper focuses on the influence of several points including IMC, TSV distribution, underfill, substrate and the structure of TSV. The finite element modeling results draw some cinclusion. Stress of both interposer and solder joint with the IMC is much larger than that without IMC. The effect of solder joint distribution is not significant to the reliability of interposer and solder joint. Underfill is beneficial to reliability of solder joint, but makes interposer stress large. The solder joint reliability is more sensitive to substrate thickness for package without underfill. It is validated by finite element analysis that the structure of unfully filled TSV is beneficial to reduce the mismatch between copper and silicon.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"11 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":"125353300","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":"High efficient and color rendering quantum dots optimized white light emitting diodes","authors":"Ziming Zhou, Yongming Zhu, Wei Chen, Yulong Chen, J. Hao, Kai Wang","doi":"10.1109/ICEPT.2015.7236815","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236815","url":null,"abstract":"Quantum dots applications in illuminants and displays have been offered a lot of expectations due to narrow and tunable emission band. Incompatibility between colloidal QDs and encapsulant and sensitivities to oxygen and moisture are still challenging for applying QDs in white light emitting diode (WLED) devices with high quality. We develop a strategy to incorporate red QDs in silica microspheres (MS) with porous structures by a non-chemical method to achieve luminescent microspheres (LMS). Due to the lattice structure of LMS maintaining large extent of QDs luminescent properties, the fabricated WLED integrated with as prepared LMS and commonly used YAG: Ce yellow phosphors demonstrates not only excellent quality white light on color coordinates (around 0.33 0.33), correlated color temperature (CCT) (5100 to 5500K), and color rendering index (CRI) (Ra=90, R9=95), but also high luminous efficiency reaching up to 142.5 lm/W at 10mA, which is the highest record in previous literatures for QDs optimized WLEDs, and high operational stability in different forward current. LMS technique revealed great potentials for applying QDs in high quality encapsulated WLED with good operational stability.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"7 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":"124058939","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":"Effects of Cu orientation on the microstructure of Sn-2Ag-2.5Zn /Cu interface","authors":"Penghui Xu, Fengtian Hu, A. Hu, Ming Li","doi":"10.1109/ICEPT.2015.7236700","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236700","url":null,"abstract":"The effects of Cu orientation on the microstructure and growth of IMCs in Sn-2Ag-2.5Zn /Cu solder joints were studied. After reflowing at 250 °C for 10 s, the continuous scallop-like IMCs Cu6Sn5 in Sn-2Ag-2.5Zn /polycrystalline Cu solder joint were more flat and thinner than that on (110), (111) oriented Cu substrates. The grain size of IMC on single crystal Cu substrates was larger than that of IMC on polycrystalline Cu. While during aging time, the growth rate of IMC on polycrystalline Cu substrates was slower, compared with that on (110), (111) oriented Cu substrates, and the thickness of IMC on (110), (111) oriented Cu substrates showed no visible differences, It was observed that the thickness of IMC was proportional to the square of the time in aging process.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"39 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":"121439404","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":"High performance silver nanowire based transparent electrodes reinforced by conductive polymer adhesive","authors":"Qisen Xie, Cheng Yang, Zhexu Zhang, Ruobing Zhang","doi":"10.1109/ICEPT.2015.7236779","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236779","url":null,"abstract":"Transparent conducting electrodes (TCEs) are an essential component for modern opto-electronic devices such as solar cells, organic light emitting diodes (OLEDs), liquid crystal displays (LCDs), and touch screen panels. However, traditional indium tin oxide (ITO) cannot meet the demand for the next generation highly flexible TCEs, and thus many novel alternative materials and technologies are blooming, such as super-aligned carbon nanotube, graphenes, conducting polymer and metal nanowire and so on. Among them, silver nanowires (Ag NWs) have been considered as one of the most promising technologies for TCEs, featured with superior electrical and optical properties. However, there are still two major challenges for Ag NWs-based TCEs technology to overcome. One is the poor mechanical interconnection between the Ag NWs conducting networks and transparent substrate, the other is the high contact resistance of the junctions among Ag NWs. Here we report a novel two-step electrostatic spraying process to fabricate Ag NWs TCEs composite with selectively coated conductive polymer, i.e. poly 3,4-ethylenedioxythiophene: polystyrenesulfonate (PEDOT:PSS). Additionally, we applied plasma treatment to the materials between two-step electrostatic spraying process, which rendered sintering of junctions between the Ag NWs at room temperature, and thus increasing the conductivity of the TCEs by at least three orders of magnitude. Results showed that by adjusting the electrostatic spraying process parameters, selective deposition can be achieved, i.e. the conductive polymer could tightly bound to the Ag NWs network. As compared to an even distribution of the coating layer in the whole area, selective coating rendered the negligible loss of transmittance (0.2% at most) and excellent adhesion to the substrate. Moreover, the composited TCEs exhibited 85.3% mean optical transmittance and 35.8 Ω/sq sheet resistance. Based on our results, we believe that this technology can be used for roll-to-roll preparation of silver nanowires (Ag NWs)-based TCEs.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"123 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":"121874235","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":"Effects of bare cu wires' mechanical properties on ball bond profile","authors":"F. Zong, Naikuo Zhou, Zhijie Wang, Yanbo Xu","doi":"10.1109/ICEPT.2015.7236549","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236549","url":null,"abstract":"Due to the advantages of low cost, good electrical/thermal properties and reliability performances, Cu wire had been used in the semiconductor industry for IC connections many years instead of Au wire. While Cu wire was harder and easier to be oxidized, this degraded its bond abilities and introduced some failures. During the primary evaluation of 33 microns bare Cu wire to replace 33/38 microns Au wire in one SOIC device, there were many irregular ball bonds with poor profiles after wire bonding; which may result into potential risks of quality and reliability failures. Based on the fish bone analysis and the following root cause validations, `inconsistent wire properties' and `improper EFO (electric-flame-off) parameters' were suspected as the root causes. Then the source of variance analysis confirmed that the former one was the main root cause. The comparison of cross sections found that the coarser and more inconsistent grains might result into the irregular ball bonds. Cu wires/FABs (free-air-ball) with finer grains would deformed more consistently and got less irregular ball bonds; while they were harder and had higher breaking load values, thus introducing impacting damages to bond pads. So the wire properties were controlled to get a balance between the ball bond profile and effects on bond pads, through controlling the breaking load considering its easy feasibilities. The final control limits of wire breaking load were shrunk to 17-19gf for this case based on the final confirmation run results.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"20 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":"116596794","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":"Fall detection analysis with wearable MEMS-based sensors","authors":"Xuebing Yuan, Shuai Yu, Qiang Dan, Guoping Wang, Sheng Liu","doi":"10.1109/ICEPT.2015.7236791","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236791","url":null,"abstract":"Accidental falls are frequent and dangerous events for the elderly population, which can result into serious injury or fracture of bones especially hip bone injury or other joint fractures. There are several methods for detecting falls of elderly, such as camera-based, personal emergency response System (PERS), and wearable sensor-based. However, the camera-based method is limited by instrumented spaces and the PERS is suffer from inability to give an alarm after a fall. The wearable sensor-based fall detection is not limited to instrumented spaces, moreover, it is easily to detect the falls through tracking the kinematic information about the monitored person. In this paper, a wearable Micro-electromechanical Systems (MEMS)-based sensors module is designed for fall detection including one three-axis accelerometer, one three-axis gyroscope and one three-axis magnetometer. However, falls from activities of daily living (ADL) make it difficult to distinguish real falls from certain fall-like activities such as sitting down quickly and jumping. An approach is proposed using attitude angles to reduce false falls through tests of static postures and dynamic transitions. Meanwhile, the proposed method has real-time response and high computation efficiency.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"16 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":"123073740","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 temperature-controlled system for loss measurement of transformer used in switched-mode power supply","authors":"Dingding Sun, Jiale Lu, Wenxiao Fang, Xiaoqi He, Xiaowen Zhang","doi":"10.1109/ICEPT.2015.7236556","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236556","url":null,"abstract":"The switch-mode power supply (SMPS) is being widely used in various fields. The reliability of SMPS is directly affected by the degradation and failure of magnetic component of transformer. It is well known that the loss of the magnetic component of transformer consist of iron loss and copper loss. In this paper, The pros and cons of several common loss measurement methods are discussed and a brief overview of temperature-controlled system for loss measurement of transformer in SMPS is proposed. The system can achieve these goals, within specified flux density and high frequency ranges, and at different temperatures, with high speed and accuracy, then MATLAB programming for data analysis and loss calculation. By doing this, The system can rapidly judge whether the damage of SMPS is caused by the loss of magnetic component.","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":"123721278","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":"Improvement of optical performances of LEDs by dual-layer structure of nano-TiO2 and phosphor","authors":"Zheng Huai, Liu Sheng, Zou Xixi, Lei Xiang, Xing Guo","doi":"10.1109/ICEPT.2015.7236760","DOIUrl":"https://doi.org/10.1109/ICEPT.2015.7236760","url":null,"abstract":"We presented a dual-layer packaging layout and its enhancement effect on light efficiency (LE) and angular color uniformity (ACU). In this packaging layout, a thin film of TiO2/ silicone nanocomposite is inserted between LED chips and phosphor layers. And the phosphor layer is a convex shape and Restricted to the surface of LED chips. The effects of TiO2 concentration and particle size on the LE and ACU performances were studied by the Monte Carlo ray-tracing optical simulation. Results show that the LE is improved up to 8.5%, and the angular color deviation is reduced from 1100 K to 180K. In nano-TiO2 composite layer, high concentration can result in higher LE and ACU. And increasing particle size can reduce the ACU deviation. But when the particle size is beyond an optimized value, the LE is significantly decreased.","PeriodicalId":415934,"journal":{"name":"2015 16th International Conference on Electronic Packaging Technology (ICEPT)","volume":"11 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":"115733205","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}