Abstract：The full Cu3Sn solder joint has been widely used in 3D packaging gradually. 270℃ and 1N were chosen as soldering temperature and pressure respectively to fabricate solder joints under different soldering time in order to analyze the process of microstructural evolution.Cu6Sn5 morphology with different soldering temperatures and time was also observed respectively to investigate the growth law of Cu6Sn5 and the effect of soldering temperature on the Cu6Sn5 morphology. The results show that scallop-like Cu6Sn5 is formed along the Cu substrate after 30min soldering, and a thin layer of Cu3Sn is generated between Cu6Sn5 and Cu substrate.When the soldering time is increased to 60min, liquid Sn is totally consumed and Cu6Sn5 becomes a cohesive whole. With the increase of soldering time, Cu3Sn grows at the expense of Cu6Sn5. Cu6Sn5 is totally transformed into Cu3Sn up to 480min. The growing process of Cu6Sn5 includes nucleation, growth, fusion and covering up the big grain. With the increase of soldering temperature, the morphology of Cu6Sn5 changes from polyhedron shape to procumbent.
梁晓波, 李晓延, 姚鹏, 李扬, 金凤阳. 微电子封装中全Cu3Sn焊点形成过程中的组织演变及生长形貌[J]. 材料工程, 2018, 46(8): 106-112.
LIANG Xiao-bo, LI Xiao-yan, YAO Peng, LI Yang, JIN Feng-yang. Microstructural Evolution and Growth Morphology During Formation Process of Full Cu3Sn Solder Joint in Microelectronic Packaging. Journal of Materials Engineering, 2018, 46(8): 106-112.
 薛洁,叶菊华,管清宝,等.电子封装用氰酸酯复合材料的研究[J].材料工程,2013(4):63-67. XUE J,YE J H,GUAN Q B,et al.Novel cyanate ester resin composites for microelectricalpackaging[J]. Journal of Materials Engineering,2013(4):63-67.
 CARSON F P,KIM Y C,YOON I S.3-D stacked package technology and trends[J].Proceedings of the IEEE,2009,97(1):31-42.
 夏艳.3D集成的发展现状与趋势[J].中国集成电路,2011,7(146):23-27. XIA Y.Present situation and development of 3D integration[J].China Integrated Circuit,2011,7(146):23-27.
 HOIVIK N,K WANG,K AASMUNDTVEI,et al.Fluxless wafer-level Cu-Sn bonding for micro-and nanosystems packaging[C]//IEEE Electronic System-integration Technology Conference. Berlin:IEEE,2010:1-5.
 LEE B,J PARK,J SONG,et al.Effects of bonding temperature and pressure on the electrical resistance of Cu/Sn/Cu joints for 3D integration applications[J].J Electron Mater,2011,40(3):324-329.
 WELCH W,CHAE J,LEE S H.Transient liquid phase (TLP) bonding for microsystem packaging applications[C]//The 13th International Conference on Solid-state Sensors,Actuators and Microsystems.Seoul:IEEE,2005:1350-1353.
 LABIE R,LIMAYE P,LEE K W,et al.Reliability testing of Cu-Sn intermetallic micro-bump interconnections for 3D-device stacking[C]//Electronic System-integration Technology Conference.Berlin:IEEE,2010:1-5.
 杨东升.三维封装芯片固液互扩散低温键合机理研究[D].哈尔滨:哈尔滨工业大学,2011. YANG D S.3D packaging solid-liquid interdiffusion chip bonding mechanism under low temperature[D].Harbin:Harbin Institute of Technology,2011.
 CAO Y H,NING W G,LUO L.Wafer-level package with simultaneous TSV connection and cavity hermetic sealing by solder bonding for MEMS device[J].IEEE Transactions,2009,32(3):125-132.
 CHIU W L,LIU C M,HAUNG Y S,et al.Formation of plate-like channels in Cu6Sn5and Cu3Sn intermetallic compounds during transient liquid reaction of Cu/Sn/Cu structures[J].Materials Letters,2016,164:5-8.
 ZOU H F,YANG H J,ZHANG Z F.Morphologies, orientation relationships and evolution of Cu6Sn5 grains formed between molten Sn and Cu single crystals[J].Acta Materialia,2008,56(11):2649-2662.
 YAO P,LI X,LIANG X B,et al.Investigation of soldering process and interfacial microstructure evolution for the formation of full Cu3Sn joints in electronic packaging[J]. Materials Science in Semiconductor Processing,2017,58:39-50.
 ZHAO N,ZHONG Y,HUANG M L,et al.Growth kinetics of Cu6Sn5 intermetallic compound at liquid-solid interfaces in Cu/Sn/Cu interconnects under temperature gradient[J].Scientific Reports,2015,5(4):13491-13498.
 LIU H,SALOMONSEN G,WANG K,et al.Wafer-level Cu/Sn to Cu/Sn SLID-bonded interconnects with increased strength[J].IEEE Transactions on Components,Packaging and Manufacturing Technology,2011,1(9):1350-1358.
 杜茂华,蒋玉齐,罗乐.Cu/Sn等温凝固芯片键合工艺研究[J].功能材料与器件学报,2004,10(4):467-470. DU M H,JIANG Y Q,LUO L.Study of die bonding technology for Cu/Sn isothermal solidification[J].Journal of Functional Materials and Devices,2004,10(4):467-470.
 肖慧,李晓延,李凤辉.热循环条件下SnAgCu/Cu焊点金属间化合物生长及焊点失效行为[J].材料工程,2010(10):38-42. XIAO H,LI X Y,LI F H.Growth kinetic of intermetallic compounds and failure behavior for SnAgCu/Cu solder joints subjected to thermal cycling[J].Journal of Materials Engineering,2010(10):38-42.
 高瑞婷,李晓延.加载速率和钎料厚度对SnAgCu/Cu焊点剪切行为的影响[J].焊接学报,2016,37(2):94-98. GAO R T,LI X Y.Effect of loading rates and solder thickness on shear behavior of SnAgCu/Cu lead-free solder joint[J].Transactions of the China Welding Institution,2016,37(2):94-98.
 TU K N,ZENG K.Tinlead (SnPb) solder reaction in flip chip technology[J].Materials Science and Engineering:R:Reports,2001,34(1):1-58.
 TU K N,LEE T Y,JANG J W,et al.Wetting reaction versus solid state aging of eutectic SnPb on Cu[J].Journal of Applied Physics,2001,89(9):4843-4849.
 MA C H,SWALIN R A.A study of solute diffusion in liquid tin[J].Acta Metall,1960,8(6):388-395.
 SUH J O,TU K N,LUTSENKO G V,et al.Size distribution and morphology of Cu6Sn5 scallops in wetting reaction between molten solder and copper[J].Acta Materialia,2008,56(5):1075-1083.