2021 22nd International Conference on Electronic Packaging Technology (ICEPT)最新文献

{"title":"The Study on Electromigration of Solder Joints under Thermal Cycling Load","authors":"Leyi Niu, Xiaodi Tian, F. Jia","doi":"10.1109/ICEPT52650.2021.9567916","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9567916","url":null,"abstract":"As the main components of aerospace, home appliances and smart equipment, electronic packaging devices are gradually developing towards miniaturization, lightweight and multi-function, which leads to more and more reliability problems. BGA solder joints play the role of mechanical support and electrical connection between the chip and the PCB board. It is prone to electromigration failure under the condition of high current density, which is one of the most important problems restricting the development of chips. In this study, the electromigration failure of solder joint in WLCSP package with BGA interconnects is investigated by establishing the multi-physical fields. Based on the finite element simulation software COMSOL, the current density, temperature, stress, and concentration on the electromigration behavior of solder joints are taken into account by fully-coupled transient analysis. And the birth and death element method is applied to simulation of voids. Meanwhile, the effects of thermal cycling load and thermal conductivity of voids are considered. According to mass diffusion theory and voids formation and expansion criterion, the thermal characteristics and failure behavior of solder joint under the thermoelectric condition were studied. At the last, the failure time of solder joint is determined according to the failure criterion of electromigration. The result shows that the temperature, stress, and atomic concentration of solder joint change periodically with the thermal cycling load. During the ramp rate stage, the temperature and stress of the solder joints change accordingly, while there is no remarkable effect on atomic concentration and voids generation rate. At the high-temperature dwell time, the maximum temperature and stress of the solder joint occur on the cathode side. Its atomic concentration drops rapidly, which is the main stage of voids generation. Voids mainly formed at the cathode corner of the solder joint, which will cause the current density continue to increase and stress concentration. Thus, electromigration is accelerated and the failure life of solder joint became shorter. When the current is 1.5A, the failure time of the solder joint is about 516 cycles.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129358052","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 novel Cu@Sn@Ag core-shell particles for die attachment in power device packaging","authors":"Jiahao Liu, Hui Xiao, X. Guo, Xinjie Wang, Zhijun Yao, Xingchao Mao, Hao Liu, Hongtao Chen","doi":"10.1109/ICEPT52650.2021.9568006","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9568006","url":null,"abstract":"This paper prepares a novel Cu@Sn@Ag core-shell particles as the die attach material. By the method of Transient Liquid Phase (TLP), the power device can be packaged to realize electrical interconnection and heat conduction. After electroless plating by two-step method, the Cu particles can be coated with Sn layer and Ag layer, successively. The resulting Cu@Sn@Ag particles were compressed into preform. After reflow for 15 min at 250°C, the interconnection can be completed between devices and Substrates. According to the results of SEM, EDS, and XRD, the resulting bondline consists of three phases, namely, Cu3Sn, Ag3Sn and Cu, which indicates that the sample after reflow can withstand high temperature (>475 °C, the melting point of Ag3Sn). Besides, the resulting bondline revealed excellent mechanical properties and thermal properties. After shear testing at high temperature (400°C), the average shear strengths can be maintained at 25.3 MPa. After thermal shocks for 500 cycles, the interface between bondline and substrate was effectively interconnected, rather than occurred the failure. As a novel material for die attachment, the Cu@Sn@Ag core-shell particles reveal great potential of exploration in the field of power device packaging.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130410127","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":"Study on thermal stability of all copper interconnect structures under thermal shock","authors":"Hao Li, Jun Shen, Jiacheng Xie","doi":"10.1109/ICEPT52650.2021.9568106","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9568106","url":null,"abstract":"Copper nanoparticles have become a new generation of chip interconnection materials with considerable application prospects due to their excellent electrical and thermal properties, good electromigration resistance, and low economic cost. Different all copper interconnects were prepared by air sintering and vacuum sintering respectively, and the thermal shock test was carried out. The mechanical and electrical properties of the interconnects after thermal shock cycle were tested. Combined with microstructure characterization and theoretical analysis, the influence of thermal shock conditions on the thermal stability of all-copper interconnects was studied. The experimental results indicated that the bonding strength of the all-copper interconnection structure decreased first and then increased slightly with the number of thermal shock cycles. After 1000 cycles, the interconnection structures prepared by air sintering and vacuum sintering still maintain good bonding strength, and the average shear strength is respectively 23.24 MPa and 25.01 MPa.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129299782","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":"Design and fabrication of a soft micro-actuator based on distributed magnetic composite","authors":"L. Wang, Shimei Liu, Hu He","doi":"10.1109/ICEPT52650.2021.9568222","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9568222","url":null,"abstract":"Benefit from the development of micro/nano manufacturing and flexible electronics technology, soft micro-actuators which could be potentially applied in drug delivering and environment monitoring have developed rapidly in recent years. Due to the simplicity of fabrication process and flexibility of control strategies, magnetic-controlled soft actuators based on magnetic-responsive composites have attracted intensive interests. In literature, lots of works focus on the structure and manufacturing process of the micro-actuators in order to enhance their driving performance. However, as fully soft micro-actuators, the driving efficiency of the soft parts is comparatively low, and the stability is poor in a liquid environment. In this work, a micro-actuator combined with rigid and flexible parts was presented to improve the driving force as well as the stability. We proposed a method of using substrates with higher stiffness to manufacture the nonuniform stiffness composites. The magnetic unit is made of magnetic particles mixed with rigid substrate, and then embedded in or connected with the flexible body. Following this strategy, the rigid sections take responsible for quick magnetic response while the soft area have desired deformation performance. Firstly, the magnetic response of magnetic composite made of epoxy resin was analyzed. Then, hysteresis loop test was deployed to investigate the effect of magnetic particle concentration on magnetic properties. Furthermore, the deformation of the composite actuator is analyzed by simulation with respect to the different positions and quantity of the rigid parts. Finally, the fabricated soft micro-actuator is controlled by external magnetic field to demonstrate the potential applications. It was believed that the combination of rigid and flexible components in micro electro mechanical system is beneficial to improve the driving ability and broaden the application range of micro actuators.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114699590","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":"Thermodynamic simulation and analysis of metal bumps in flip-chip micro-LED packaging","authors":"Xiaoyu Xiao, Yamei Yan, Gui Chen, Wenhui Zhu","doi":"10.1109/ICEPT52650.2021.9568029","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9568029","url":null,"abstract":"Thermal compression bonding provides a good solution for the packaging of micro-LED chips, greatly increases the resolution of micro-led, and can achieve higher density integration and better display effect. In order to study the thermomechanical reliability and display stability of micro-LED devices under thermal cycling load and working power load, this paper first explains the limitation of thermal expansion coefficient (CTE) mismatch on the size of flip chip devices by mathematical method, and proposes a low temperature indium bump flip chip bonding technology which can overcome this defect. Then, the finite element model is established to study the influence of different metal bump materials on the reliability of micro-LED devices under thermal cycling load, and the display stability is analyzed combined with the wavelength drift characteristics of micro-LED devices.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114876710","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":"Double-sided Electroplating Process for Through Glass Vias (TGVs) Filling","authors":"Ke Li, Heng Wu, W. Chen, Daquan Yu","doi":"10.1109/ICEPT52650.2021.9568055","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9568055","url":null,"abstract":"This article reported a through-glass vias(TGVs) plating technology based on glass substrates. As one of the important technologies for continuation of Moore's law, through holes play the role of electrical connection on both sides. The TGVs were formed by laser drilling on the glass substrate, sputtering titanium as a barrier layer, and copper as a seed layer, and its diameter-to-depth ratio was about 1:4. Due to the difference in the layout of the metal wiring on both sides of the wafer, there is a difference between the plating area on both sides of the wafer and the current distribution during electroplating. Therefore, the double-sided electroplating technology reported in this article has successfully achieved void-free hole filling through convection strength, additives, current density, conduction mode, and can ensure that the uniformity on both sides meets the requirements. This electroplating technology has been used in mass-produced products, and can also realize copper filling in through holes of other structures.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124268415","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":"Design and Analysis of MOSFET Based on Fan-out Panel-Level Package Technology","authors":"Z. Liang, Dongdong Shao, Kunpeng Ding, Chuang Tian","doi":"10.1109/ICEPT52650.2021.9568028","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9568028","url":null,"abstract":"Nowadays, fan-out package has received extensive attention from enterprises and researchers because it possesses lower cost, smaller size, higher packaging efficiency, and better electrical and thermal performance. As one of the fan-out packages, panel-level fan-out package has advantages in single package cost, board utilization, and packaging efficiency. In this paper, based on the panel-level fan-out package process, a power MOSFET device is designed, which is composed of pads, solder, chip, circuits and molding compound. The drain of the chip is fixed on the copper pad by solder, and the gate and source are interconnected with the pads through laser drilling and electroplating processes. Finally, realize the electrical connection of the chip. In addition, the thermal resistance of the MOSFET device is analyzed by the commercial software ICEPAK. The results show that the thermal resistance of MOSFET based on fan-out panel-level package process is 43.44°C /W, which is 11.4% lower than the traditional wire-bonding process. The MOSFET based on fan-out panel-level package process has good heat dissipation performance.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126221659","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 Formation of Cn-Sn IMC Interconnection by Solid-Liquid Interdiffusion Bonding for 3D Glass Wafer Stacking","authors":"Yangquan Su, Kuili Ren, Yiyong Huang, Mingchuan Zhang, Daquan Yu","doi":"10.1109/ICEPT52650.2021.9568223","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9568223","url":null,"abstract":"Wafer bonding technology promotes 3D system integration and packaing. In this paper, the Cu/Sn low-temperature bonding for 3D glass wafer stacking is studied. The effects of temperature, pressure and time on the bonding process are demonstrated by experiments and simulations. The formation of ${text{Cu}_{3}text{Sn}}$ is incorporated into Cu/Sn bonding interface. For 5G devices, such as the applications of millimeter wave, terahertz and internet of things (IoT), advanced packaging using glass substrate with excellent electrical properties is promising. Based on the laser inducing and wet etching, through glass vias (TGV) were fabricated, and the vias wre filled with Cu. Then, the Cu/Sn RDL is electroplated to form a stacked structure for multi-layer bonding. To optimize the process, Cu/Sn bonding surface and TGV cross section are analyzed by scanning electron microscope (SEM). And the ratio of Cu/Sn alloy are measured with an energy spectrometer. Based on X-ray photography, there are no bonding defects. The seal ring formed by bonding can effectively protect the electrical signals transmitted in the TGV. There is no leakage in the seal ring, the amount of Sn overflow during the bonding process is limited, and it does not affect the TGV and metal trace near the sealing ring.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126447426","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 Analysis of Coupling Coil of 13.56MHz Magnetic Coupling Resonant Wireless Energy Transmission System","authors":"Bihong Zhan, Wei Xia, Chunshui Xiong, Sheng Liu","doi":"10.1109/ICEPT52650.2021.9568095","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9568095","url":null,"abstract":"To find a new growth point for the improvement of the coupling coil transmission efficiency in the 13.56 MHz magnetic coupling resonant wireless energy transmission (WET) system, and to provide a new solution for the improvement of the transmission efficiency of the entire system. This paper takes the coupling coil (including the primary transmitting coil and the secondary receiving coil) in the 13.56 MHz magnetic coupling resonance WET system as the basic research object. First, the Ansoft HFSS simulation software is used to digitally model the coupling coil, and the inductance value of the coupling coil and the magnetic induction intensity (denote by $boldsymbol{B}$) around a single coil are obtained through simulation calculations. Furthermore, through simulation, the distribution of magnetic induction intensity and magnetic induction intensity vector under different transmission distances between the coupling coil are obtained. Secondly, the coupling coil model established by Solidworks software was imported into Ansoft Maxwell simulation software in a certain format, and the magnetic field distribution at different vertical distances between the coupling coil and the offset distance of the central axis were obtained through simulation calculations. In this paper, the problem of the transmission efficiency of the coupling coil is transformed into the problem of the coupling coefficient, and the coupling coefficient and mutual inductance between the coupling coil at different transmission distances are obtained by Ansoft Maxwell simulation calculation, and the effects of the vertical distance between the coupling coil and the offset distance of the central axis on the coupling coefficient and mutual inductance of the coupling coil are analyzed. Finally, this article uses Ansoft HFSS to simulate and analyze the influence of the composite film on the inductance and magnetic field distribution of the coupling coil. This will provide a theoretical basis for the integration of the composite film in the 13.56 MHz magnetic coupling resonance WET system.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125448475","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 modification of graphite and its effect on thermal and mechanical properties of graphite-based thermal interface materials","authors":"Yuexing Zhang, Hong He, Junwei Li, Chenxu Zhang, R. Sun, Meng Han, Ping Zhang","doi":"10.1109/ICEPT52650.2021.9567980","DOIUrl":"https://doi.org/10.1109/ICEPT52650.2021.9567980","url":null,"abstract":"Graphite has been widely used in the preparation of polymer-based thermal interface materials with excellent performance due to its high thermal conductivity. However, there is a huge difference in the surface energy between graphite and polymer matrix, which can lead to the aggregation of graphite powder in the composite system. Because of the agglomeration, the thermal transport paths in the thermal interface materials are blocked. The main strategy to solve such a problem is to perform surface modification on graphite, which can improve the dispersion of graphite and build more transfer paths. In this work, the graphite was hydroxylated by oxidation firstly, then the dodecyl trimethoxy silane, hexadecyl trimethoxy, and titanate coupling agent were grafted onto the graphite surface by wet modification. Then, the thermal interface material was prepared by adding original and modified graphite in the polymer, and their thermal and mechanical properties were studied and compared. Experimental results showed that the thermal properties of the two groups had no significant difference. With the graphite content increasing from 45 wt.% to 60 wt.%, the thermal conductivity increased from 11 W/(m.K) to 21.5 W/(m.K). After three cycles of compressions, the stress of modified samples was smaller under the same strain. This means that the modified sample has better compression resilience and can work more stably under certain cyclic compression. This work provides important information for the surface modification of graphite to improve its thermal and mechanical behaviors in thermal interface materials.","PeriodicalId":184693,"journal":{"name":"2021 22nd International Conference on Electronic Packaging Technology (ICEPT)","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134115220","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}