纯锡覆层晶须生长及无铅焊点电迁移的研究
|
摘要
本文以电子封装的无铅材料为对象,分别采用试验、理论分析、数值模拟和数学推导的方法系统研究了纯Sn覆层在温度循环条件下的晶须生长机理,高温(160°C)和高电流密度(2.2×10~4A/cm~2)、室温(25°C)和较低电流密度(0.4×10~4A/cm~2)条件下无铅焊点的电迁移机理,得到以下主要研究结论:
在温度循环条件下,锡须从镀层表面裂纹处生长,其密度与表面裂纹的数量有关,其长度与循环次数有关。不同电镀酸液配方通过影响镀层微观结构来促进锡须生长,Mix酸液的镀层锡须生长密度高于MSA酸液的2~3个数量级,前者的锡须长度大于后者的锡须长度;表面裂纹越多,锡须生长的密度速率越高。随着循环次数的增加,生长快的锡须长度速率下降、生长慢的锡须长度速率上升,所有锡须的长度有逐渐趋于一致的态势。Cu_6Sn_5的楔形生长及迁移包含了三个阶段:Cu_6Sn_5在Cu-Sn界面处的生长,Sn大晶粒的分割及小晶粒的再结晶,Cu_6Sn_5沿Sn晶粒的晶界迁移。镀层中的晶粒层数越多、晶粒尺寸越小、其晶界也越多,越有利于松弛内部压应力、抑制锡须生长。晶粒的取向为低指数(101)、(112)、(220)和(211)晶面时,镀层不容易生长锡须;晶粒的取向为高指数(321)和(312)晶面时,镀层容易生长锡须。低指数晶面的晶界是大角度晶界(>15°),能提供更多的空位以松弛内部压应力;锡须生长使镀层的晶粒取向由高指数晶面和较小角度晶界转变为低指数晶面和大角度晶界。不同材料的热膨胀系数和杨氏模量差异导致在氧化膜内产生热应力;水平的热应力会产生一个垂直于氧化膜的切应力分量形成对氧化膜晶界的剪切,加剧应力集中、削弱晶界强度、产生沿晶裂纹。镀层表面越粗糙,垂直于氧化膜的切应力分量越大,表面裂纹和锡须生长也越多。镀层的致密度可以用于评估镀层表面裂纹生长的趋势,致密度越高的镀层表面裂纹越少、锡须生长越少。
在电迁移过程中,焊点阴极界面的IMC长大、剥落和迁移,形成IMC的极性生长和演化。阴极UBM耗尽后Cu层开始溶解,Cu层附近区域IMC为Cu_6Sn_5,焊料中阴极附近区域IMC为Ni_3Sn_4;迁移到阳极IMC为(Cu_x,Ni_(1-x))_6Sn_5。高温/高电流密度条件下的电迁移包含了初始、空洞扩展和快速失效三个阶段;室温和较低平均电流密度条件下的电迁移只发现了初始和快速失效两个阶段,空洞扩展阶段不显著。初始和空洞扩展阶段经历的时间很长,快速失效阶段经历的时间很短。在高温/高电流密度条件下,大空洞在阴极界面形成和扩展,与IMC迁移的方向垂直;其驱动力为IMC形成时体积缩小产生的拉应力和转角处电流聚集产生的由内侧向外侧的应力梯度。在室温/较低电流密度条件下,焊点阴极界面没有发现大块IMC和空洞,焊点内部的IMC数量和尺寸都很小。在电迁移初始阶段,界面反应是准平衡态的可逆过程;在电迁移快速失效阶段,界面反应是非平衡态的不可逆过程。当0.4T_mT_m,界面反应主要为固/液界面反应,浓度梯度引起的原子迁移和温度梯度引起的热迁移是原子迁移的主要方式。数值模拟表明,电流密度聚集是产生电迁移失效的根本原因,焊点的实际温度低于100°C,避免了高温下原子热扩散对电迁移的干扰。不均匀的温度分布产生较大的热应力,由于Ni/Cu层在XY平面受到约束,因此变形主要在Z方向;热应力越大的焊点其变形量也越大。
电迁移条件下,焊点的Ni-Sn扩散偶中存在两种扩散组元:Sn(A组元)和Ni(B组元)。根据唯象方程,推导出试验条件下阴极和阳极扩散反应区的不同原子净流量和界面IMC的生长速率表达式。焊点中阴极界面IMC生长速率比阳极更快;不同焊点的温度差异引起了阴极界面的原子净流量和IMC的生长速率差异,导致不同焊点的电迁移程度差异。根据焊点中阴极和阳极温度、不同组元的浓度C和扩散系数D差别不大的假设,建立了阴极和阳极IMC厚度之差及厚度之和与不同原子迁移力的表达式。Sn的热迁移力比其电迁移力小两个数量级、比Ni的电迁移力小一个数量级;Ni的应力迁移力约为其电迁移力的几分之一;Sn的电迁移力比Ni的电迁移力大,二者都在同一个数量级(10~(17)N)水平。IMC中Ni的扩散系数与Sn和Ni的浓度梯度迁移力相关,是一个取决于温度和试验条件的参数;此外,二者的浓度梯度迁移力的大小约为10~(-16)N数量级,略高于电迁移力。因此;电迁移力和浓度梯度迁移力是IMC生长的主要驱动力。
This thesis studied the mechanisms of Sn whiskers growth on the pure Sn coating in Thermal Cycling(TC) condition and electromigration of lead-free solder joints in two onditions: High temperature(160°C)/High current density (2.2×10~4A/cm~2) (HH) and Low temperature(25°C)/Low current density (0.4×10~4A/cm~2) (LL).
Under the TC condition, whiskers grew from the surface cracks on the coating. Their density and length were relative to the quantities of cracks and the times of thermal cycling, respectively. The chemical composition of electroplating solution changed the coating microstructures to form surface cracks and promote whiskers growth. The coating applied Mix acid chemical had the much higher density and larger length in whiskers growth than that applied MSA acid chemical.
The length of all whiskers has a trendency to be uniform with cycles increasing. Cu_6Sn_5 wedge has three stages in growth and migration. Cu_6Sn_5 grows at the Cu-Sn interface to wedge in a large Sn grain at first. And then, Cu_6Sn_5 growth divides the large Sn grain into two grains and changes their crystal orientations to re-crystallize them. Finally Cu_6Sn_5 migrates along the boundaries of Sn grains. More layers and smaller sizes of Sn grains will provide more grain boundaries to relax the inner compressive stress and suppressing whiskers growth. Sn grains with low-index lattice planes, such as (101), (112), (220) and (211) can retard whiskers growth. Inversely, Sn grains with the high-index lattice lanes, such as (321) and (312) can promote whiskers growth. Grains with the low-index lattice planes have the large-angle boundaries (>15°) to absorb the inner compressive stress. The high-index lattice planes and small-angle boundaries will reverse their values with whiskers growing.
The high temperature generated a high thermal stress due to the mismatch of Young’s modules and coefficients of thermal expansion (CTE) among different materials. The shear component of the thermal stress vertically acted on the boundaries of oxide film to degrade the boundary strength and produce surface cracks. This shear force increased with the roughness of the surface. A novel compact density test was introduced to evaluate the susceptibility of cracks to the surface. The surface having a high compact density was so robust to resist cracks and whiskers growth.
During electromigration, IMCs formation and evolution appeared polar effects at the cathode and anode. After the Ni layer was consumed completely, IMCs at the Cu-Sn interface, in the solder and at the anode interface were identified as Cu_6Sn_5, Ni_3Sn_4 and (Cu_x,Ni_(1-x))_6Sn_5, respectively. In HH condition, electromigration possessed three stages, the initial stage, the void propagation stage and the failure stage. And in LL condition, electromigration possessed only two stages, the initial stage and the failure stage. In HH condition, the current crowding produced a driving force to promote large voids formation and propagation along the carhode interface and vertically the direction of electrons. In LL condition, a few IMCs and few voids were found both in the solder joint and at the cathode interface.
To thermodynamic principles, the interfacial reaction is a quasi-equilibrium state in the initial stage and is a non-equilibrium state in the failure stage. When 0.4T_mT_m, the atomic migration driven by concentration and temperature gradients are dominant. The numerical simulation reveals that the current crowding is the most reason to electromigration. In this study, the actual temperatures in different solder joints were below 100°C, which did not induce magnificent atoms thermodiffusion to submerge electromigration. However, different temperature distributions caused the thermal stress and strain according to Young’s modules and CTE mismatch among different materials. The large strain appeared in Z direction because the deformations were restricted in XY plane as the thermal stress was high.
In electromigration, the expressions to atomic flux and Ni-Sn IMC growth rate have been derived from the phenomenological equations. IMCs have a faster rate to grow at the cathode than that at the anode. The different temperature generates the difference of atomic fluxes and IMCs growth rates at the cathode, which also causes the nonuniform electromigration degree in different solder joints. If concentrations and diffusivities of both elements are same in IMCs at the cathode and anode, respectively, the expressions of different atomic driving forces can be established correlative to the IMCs thickness sum and difference. The electromigrstion force of Sn atom is not only larger than that of Ni atom, but also two order magnifications than the thermomigration force of itslef. The electromigration force of Ni atom is multi-times than the stressmigration force of itslef. Although the electromigration forces of Sn and Ni atom reach 10~(17)N, the concentration-migration forces of them seem to be 10~(-16)N. It is sure that the electromigration and concentration-migration force are the main driving forces for IMCs formation and growth.
在温度循环条件下,锡须从镀层表面裂纹处生长,其密度与表面裂纹的数量有关,其长度与循环次数有关。不同电镀酸液配方通过影响镀层微观结构来促进锡须生长,Mix酸液的镀层锡须生长密度高于MSA酸液的2~3个数量级,前者的锡须长度大于后者的锡须长度;表面裂纹越多,锡须生长的密度速率越高。随着循环次数的增加,生长快的锡须长度速率下降、生长慢的锡须长度速率上升,所有锡须的长度有逐渐趋于一致的态势。Cu_6Sn_5的楔形生长及迁移包含了三个阶段:Cu_6Sn_5在Cu-Sn界面处的生长,Sn大晶粒的分割及小晶粒的再结晶,Cu_6Sn_5沿Sn晶粒的晶界迁移。镀层中的晶粒层数越多、晶粒尺寸越小、其晶界也越多,越有利于松弛内部压应力、抑制锡须生长。晶粒的取向为低指数(101)、(112)、(220)和(211)晶面时,镀层不容易生长锡须;晶粒的取向为高指数(321)和(312)晶面时,镀层容易生长锡须。低指数晶面的晶界是大角度晶界(>15°),能提供更多的空位以松弛内部压应力;锡须生长使镀层的晶粒取向由高指数晶面和较小角度晶界转变为低指数晶面和大角度晶界。不同材料的热膨胀系数和杨氏模量差异导致在氧化膜内产生热应力;水平的热应力会产生一个垂直于氧化膜的切应力分量形成对氧化膜晶界的剪切,加剧应力集中、削弱晶界强度、产生沿晶裂纹。镀层表面越粗糙,垂直于氧化膜的切应力分量越大,表面裂纹和锡须生长也越多。镀层的致密度可以用于评估镀层表面裂纹生长的趋势,致密度越高的镀层表面裂纹越少、锡须生长越少。
在电迁移过程中,焊点阴极界面的IMC长大、剥落和迁移,形成IMC的极性生长和演化。阴极UBM耗尽后Cu层开始溶解,Cu层附近区域IMC为Cu_6Sn_5,焊料中阴极附近区域IMC为Ni_3Sn_4;迁移到阳极IMC为(Cu_x,Ni_(1-x))_6Sn_5。高温/高电流密度条件下的电迁移包含了初始、空洞扩展和快速失效三个阶段;室温和较低平均电流密度条件下的电迁移只发现了初始和快速失效两个阶段,空洞扩展阶段不显著。初始和空洞扩展阶段经历的时间很长,快速失效阶段经历的时间很短。在高温/高电流密度条件下,大空洞在阴极界面形成和扩展,与IMC迁移的方向垂直;其驱动力为IMC形成时体积缩小产生的拉应力和转角处电流聚集产生的由内侧向外侧的应力梯度。在室温/较低电流密度条件下,焊点阴极界面没有发现大块IMC和空洞,焊点内部的IMC数量和尺寸都很小。在电迁移初始阶段,界面反应是准平衡态的可逆过程;在电迁移快速失效阶段,界面反应是非平衡态的不可逆过程。当0.4T_m
电迁移条件下,焊点的Ni-Sn扩散偶中存在两种扩散组元:Sn(A组元)和Ni(B组元)。根据唯象方程,推导出试验条件下阴极和阳极扩散反应区的不同原子净流量和界面IMC的生长速率表达式。焊点中阴极界面IMC生长速率比阳极更快;不同焊点的温度差异引起了阴极界面的原子净流量和IMC的生长速率差异,导致不同焊点的电迁移程度差异。根据焊点中阴极和阳极温度、不同组元的浓度C和扩散系数D差别不大的假设,建立了阴极和阳极IMC厚度之差及厚度之和与不同原子迁移力的表达式。Sn的热迁移力比其电迁移力小两个数量级、比Ni的电迁移力小一个数量级;Ni的应力迁移力约为其电迁移力的几分之一;Sn的电迁移力比Ni的电迁移力大,二者都在同一个数量级(10~(17)N)水平。IMC中Ni的扩散系数与Sn和Ni的浓度梯度迁移力相关,是一个取决于温度和试验条件的参数;此外,二者的浓度梯度迁移力的大小约为10~(-16)N数量级,略高于电迁移力。因此;电迁移力和浓度梯度迁移力是IMC生长的主要驱动力。
This thesis studied the mechanisms of Sn whiskers growth on the pure Sn coating in Thermal Cycling(TC) condition and electromigration of lead-free solder joints in two onditions: High temperature(160°C)/High current density (2.2×10~4A/cm~2) (HH) and Low temperature(25°C)/Low current density (0.4×10~4A/cm~2) (LL).
Under the TC condition, whiskers grew from the surface cracks on the coating. Their density and length were relative to the quantities of cracks and the times of thermal cycling, respectively. The chemical composition of electroplating solution changed the coating microstructures to form surface cracks and promote whiskers growth. The coating applied Mix acid chemical had the much higher density and larger length in whiskers growth than that applied MSA acid chemical.
The length of all whiskers has a trendency to be uniform with cycles increasing. Cu_6Sn_5 wedge has three stages in growth and migration. Cu_6Sn_5 grows at the Cu-Sn interface to wedge in a large Sn grain at first. And then, Cu_6Sn_5 growth divides the large Sn grain into two grains and changes their crystal orientations to re-crystallize them. Finally Cu_6Sn_5 migrates along the boundaries of Sn grains. More layers and smaller sizes of Sn grains will provide more grain boundaries to relax the inner compressive stress and suppressing whiskers growth. Sn grains with low-index lattice planes, such as (101), (112), (220) and (211) can retard whiskers growth. Inversely, Sn grains with the high-index lattice lanes, such as (321) and (312) can promote whiskers growth. Grains with the low-index lattice planes have the large-angle boundaries (>15°) to absorb the inner compressive stress. The high-index lattice planes and small-angle boundaries will reverse their values with whiskers growing.
The high temperature generated a high thermal stress due to the mismatch of Young’s modules and coefficients of thermal expansion (CTE) among different materials. The shear component of the thermal stress vertically acted on the boundaries of oxide film to degrade the boundary strength and produce surface cracks. This shear force increased with the roughness of the surface. A novel compact density test was introduced to evaluate the susceptibility of cracks to the surface. The surface having a high compact density was so robust to resist cracks and whiskers growth.
During electromigration, IMCs formation and evolution appeared polar effects at the cathode and anode. After the Ni layer was consumed completely, IMCs at the Cu-Sn interface, in the solder and at the anode interface were identified as Cu_6Sn_5, Ni_3Sn_4 and (Cu_x,Ni_(1-x))_6Sn_5, respectively. In HH condition, electromigration possessed three stages, the initial stage, the void propagation stage and the failure stage. And in LL condition, electromigration possessed only two stages, the initial stage and the failure stage. In HH condition, the current crowding produced a driving force to promote large voids formation and propagation along the carhode interface and vertically the direction of electrons. In LL condition, a few IMCs and few voids were found both in the solder joint and at the cathode interface.
To thermodynamic principles, the interfacial reaction is a quasi-equilibrium state in the initial stage and is a non-equilibrium state in the failure stage. When 0.4T_m
In electromigration, the expressions to atomic flux and Ni-Sn IMC growth rate have been derived from the phenomenological equations. IMCs have a faster rate to grow at the cathode than that at the anode. The different temperature generates the difference of atomic fluxes and IMCs growth rates at the cathode, which also causes the nonuniform electromigration degree in different solder joints. If concentrations and diffusivities of both elements are same in IMCs at the cathode and anode, respectively, the expressions of different atomic driving forces can be established correlative to the IMCs thickness sum and difference. The electromigrstion force of Sn atom is not only larger than that of Ni atom, but also two order magnifications than the thermomigration force of itslef. The electromigration force of Ni atom is multi-times than the stressmigration force of itslef. Although the electromigration forces of Sn and Ni atom reach 10~(17)N, the concentration-migration forces of them seem to be 10~(-16)N. It is sure that the electromigration and concentration-migration force are the main driving forces for IMCs formation and growth.
引文
[1] K.G. Compton, A. Mendizza, and S.M. Arnold. Filamentary Growths on Metal Surfaces– Whiskers. Corrosion, 1951, 7(10): 327-334
[2] Brusse, G. Ewell, and J. Siplon. Tin Whiskers: Attributes and Mitigation. In: Capacitor and Resistor Technology Symposium (CARTS 02). New Orleans, USA, March 25-29, 2002
[3] Basic Informations Regarding Tin Whiskers. NASA Goddard Space Flight Center. (http://nepp.nasa.gov/whisker/background/index.htm#q3)
[4] iNEMI Recommendations on Lead-Free Finishes for Components Used in High-Reliability Products Version 4 (12-1-06). (http://thor.inemi.org) 2-3
[5] Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment Regulations. RoHS, 2005 (http://www.netregs.gov.uk/netregs/legislation /380525/477158/)
[6] M.O. Peach. Mechanism of Growth of Whiskers on Cadmium. J. Appl. Phys.(letters to the editor), 1952, 23(12): 1401-1403
[7] S.E. Koonce and S.M. Arnold, .Growth of Metal Whiskers. J. Appl. Phys.(letters to the editor), 1953, 24(3): 365-366
[8] F.C. Frank. On Tin Whiskers. Phil. Mag., XLIV (7). 1953: 854-860
[9] J.D. Eshelby. A Tentative Theory of Metallic Whisker Growth. Phys. Rev. 1953, 91: 755-756
[10] J. Franks. Growth of Whiskers in the Solid Phase. Acta Metallurgica, 1958, 6(2): 103-109
[11] S. Amelinckx, W. Bontinck, W. Dekeyser, et al. On the Formation and Properties of Helical Dislocations. Phil. Mag., Ser. 8th Ser., 1957, 2(15): 355-377
[12] G.S. Baker. Angular Bends in Whiskers. Acta Metallurgica, 1957, 5(7): 353-357
[13] W.C. Ellis, D.F. Gibbons, R.C. Treuting. Growth of Metal Whiskers from the Solid. Growth and Perfection of Crystals. Edited by R.H. Doremus, B.W. Roberts, and D. Turnbull, New York: John Wiley & Sons, 1958: 102-120
[14] V.K. Glazunova and N.T. Kudryavtsev. An Investigation of the Conditions of Spontaneous Growth of Filiform Crystals on Electrolytic Coatings. Translated fromZhurnal Prikladnoi Khimii, 1963, 36(3): 543-550
[15] T. Kakeshita, K. Shimizu, R. Kawanaka, et al. Grain size effect on electroplated tin coatings on whisker growth. J. Mater. Sci., 1982, 17(9): 2560-2566
[16] J. B. LeBret and M. G. Norton. Electron microscopy study of tin whisker growth. J. Mater. Res., 2003, 18(2): 585-593
[17] Boguslavsky and P. Bush. Recrystallization principles applied to whisker growth in tin. In: Proc. APEX Conf., Anaheim, CA, 2003: S12-4-1–S12-4-10
[18] K.N. Tu. Irreversible Processes of Spontaneous Whisker Growth in Bimetallic Cu-Sn Thin Reactions. Phys. Rev. B, 1994, 49(3): 2030-2034
[19] R.M. Fisher, L.S. Darken, and K.G. Carroll. Accelerated Growth of Tin Whiskers. Acta Metallurgica. 1954, 2(3): 368-372
[20] R.R Hasiguti. A Tentative Explanation of the Accelerated Growth of Tin Whiskers. Acta Metallurgica (letters to the editor), 1955, 3(2): 200-201
[21] B.Z. Lee and D.N. Lee. Spontaneous Growth Mechanism of Tin Whiskers. Acta Metallurgica, 1998, 46(10): 3701-3714
[22] Y. Zhang, C. Xu, C. Fan, et al. Understanding Whisker Phenomenon-Part I: Growth Rates. In: Proc. of the 2001 AESF SUR/FIN Conf., UAS, 2001: NA
[23] C. Xu, C. Fan, A. Vysotskova, et al. Understanding Whisker Phenomenon-Part II, Competitive Mechanisms. In: Proc. of the 2001 AESF SUR/FIN Conf., USA, 2001: NA
[24] Y. Zhang, C. Xu, C. Fan, et al. Understanding Whisker Phenomenon: Whisker Index and Tin/Copper, Tin/Nickel Interface. In: Proc. IPC SMEMA APEX Conf., 2002, S-06-1-1~10
[25] C. Xu, Y. Zhang, C. Fan, et al. Understanding Whisker Phenomenon Driving Forces for the Whisker Formation. In: Proc. IPC SMEMA APEX Conf., 2002: S-06-2-1~6
[26] K.N. Tu. Inter-diffusion and Reaction in Bimetallic Cu-Sn Thin Films. Acta Metallurgica, 1973, 21(4): 347-354
[27] Egli, W. Zhang, J. Heber, et al. Where Crystal Planes Meet: Contribution to the Understanding of the Whisker Growth Process. In: IPC Annual Meeting, USA, 2002: S08-3-1~5
[28] W.J. Choi, T.Y. Lee, and K.N. Tu. Structure and Kinetics of Sn Whisker Growth on Pb-free Solder Finish. In: Proc. 52nd Elec. Comp. & Tech. Conf., USA, 2002:628-633
[29] W.J. Choi, T.Y. Lee, K.N. Tu, et al. Tin Whiskers Studied by Synchrotron Radiation Scanning X-ray Micro-Diffraction. Acta Materialia, 2003, 51(20): 6253-6262
[30] G.T.T. Sheng, C.F. Hu, W.J. Choi, et al. Tin Whiskers Studied by Focused Ion Beam Imaging and Transmission Electron Microscopy. J. Appl. Phys., 2002, 92(1): 64-69
[31] J. Chang-Bing Lee, Y-L.Yao, F-Y. Chiang, et al. Characterization Study of Lead-free SnCu Plated Packages. In: Proc. IEEE Elect. Comp. & Tech. Conf., USA, 2002: 1238-1245
[32] K.N. Tu and K. Zeng. Reliability Issues of Pb-free Solder Joints in Electronic Packaging Technology. In: Proc. IEEE Elect. Comp. & Tech. Conf., USA, 2002: 1194-1199
[33] S.M. Arnold. Repressing growth of tin whiskers. Plating PLATA, 1966, 53: 96-99
[34] S.C. Britton. Spontaneous Growth of Whiskers on Tin Coatings: 20 Years of Observation. Trans. of the Institute of Metal Finishing, 1974, 52: 95-102
[35] M. W. Barsoum, E. N. Hoffman, R. D. Doherty, et al. Driving force and mechanism for spontaneous metal whisker formation. Phys. Rev. Lett., 2004, 93(20): 206104-1~4
[36] P. Oberndorff, M. Dittes, P. Crema, et al. Whisker formation on matte Sn influencing of high humidity. In: Proc. 55th Electron. Compon. Technol. Conf., USA, 2005: 429-433.
[37] J W Osenbach, J M DeLucca, B D Potteiger, et al. Sn corrosion and its influence on whiskers. IEEE T. Electron. Pack., 2007, 30(1): 23-35
[38] M. Dittes, P. Oberndorff, P. Crema, et al. The Effect of Temperature cycling on Tin Whisker Formation. In: The Proc. of the IPC-Jedec Conf.-Frankfort, 2003: NA
[39] S. Madra. Thermo-Mechanical Characterization of Lead-Free Tin Plating: X-Ray Diffraction Measurements and Correlation with Analytical and Numerical Models. In: Proc. of the PC-Jedec Conf.-Frankfort, 2003: NA
[40] S.M. Arnold. The Growth of Metal Whiskers on Electrical Components. In: Proc. of the IEEE Elec. Comp. Conf., 1959: 75-82
[41] B.D. Dunn. Metallurgy and Reliability in Spacecraft Electronics. Metals and Materials, 1975, 34(3): 32-40
[42] B.D. Dunn. Whisker Formation on Electronic Materials. Circuit World, 1976, 2(4): 32-40
[43] Yanada. Electroplating of Lead-Free Solder Alloys Composed of Sn-Bi and Sn-Ag. In: Proc. of the IPC Printed Circuits Expo, USA, 1998: S-11-2~7
[44] R. Schetty. Minimization of Tin Whisker Formation for Lead-Free Electronics Finishing. In: Proc. of the IPC Works Conf., USA, 2000: S-02-R3-1~6
[45] R. Schetty, N. Brown, A. Egli, et al. Lead-Free Finishes-Whisker Studies and Practical Methods for Minimizing the Risk of Whisker Growth. In: Proc. of the AESF SUR/FIN Conf., USA, 2001: 1-5
[46] D. Hillman. JCAA/ JG-PP No-Lead Solder Project: -20°C to +80°C & -55°C to +125°C Thermal Cycle Testing. In: SMTA International Conference Proceedings, 2005: 846-850
[47] J. Bradford, J. Felty and B. Russell. JCAA/ JG-PP No-Lead Solder Project: Combined Environments Test. In: SMTA International Conference Proceedings, 2005: 824-840
[48] G.J. Ewell and F. Moore. Tin Whiskers and Passive Components: A Review of the Concerns. In: Proc. of the 18th Conference on Capacitor and Resistor Technology, CARTS, 1998: 222-228
[49] M. Dittes, P.Oberndorff and L.Petit. Tin Whisker Formation - Results, Test Methods and Countermeasures. In: Proc 53rd Elec. Comp. & Tech. Conf., USA, 2003: 822-826
[50] W.K. Choi, S.K. Kang, Y.C. Sohn, et al. Study of IMC Morphologies and Phase Characteristics Affected by the Reactions of Ni and Cu Metallurgies with Pb-Free Solder Joints. In: Proc. 53rd Elec. Comp. & Tech. Conf., USA, 2003: 1190-1196
[51] J.W. Osenbach, R.L. Shook, B.T. Vaccaro, et al. Tin Whisker Mitigation: Application of Post Mold Nickel Underplate on Copper Based Lead Frames and Effects of Board Assembly Reflow. In: Proc. Surf. Mount Tech. Assoc., 2004: 724-734
[52] M. Osterman. Mitigation Strategies for Tin Whiskers. (http://www.calce.umd.edu/ lead-free/tin-whiskers/TINWHISKERMITIGATION.pdf).
[53] K.W. Moon, M.E. Williams, C.E. Johnson, et al. The Formation of Whiskers on Electroplated Tin Containing Copper. In: Proc. 4th Pacific Rim Inter. Conf. onAdvanced Materials and Processing, Japan, 2001: 1115-1118
[54] M.E. Williams, C.E. Johnson, K.W. Moon, et al. Whisker Formation on Electroplated SnCu. In: Proc. of AESF SUR/FIN Conf., 2002: 31-39
[55] Valeska Schroeder, Peter Bush, Maureen Williams, et al. Tin Whisker Test Method Development. In: IEEE Trans. Electron. Pack. Manuf., 2006, 29(4): 231-238.
[56] Oberndorff P., Dittes M., Crema P. Tin whisker formation in thermal cycling conditions. In: Proc. 53rd Elec. Comp. & Tech. Conf., USA, 2003: 183-188
[57] H. B. Huntington and A. R. Grone. Current-induced marker motion in gold wires. J. Phys. Chem. Solids 1961, 20(1/2): 76-87
[58] Aris Christou. Electromigration and electronic device degradation. 1st Edition. Canada: John Wiley & Sons, Inc., 1994: 1-46
[59] International Roadmap for Semiconductor Technology. Semiconductor Industry Association, 1999
[60] P.S. Ho, H.B. Huntington. Electromigration and void observation in silver. J. Phys. Chem. Solids, 1966, 27(8): 1319-1329
[61] J.F. D’amico, H.B. Huntington. Electromigration and thermomigration in Gamma-uranium. J. Phys. Chem. Solids, 1969, 30(11): 2607-2621
[62] H.B. Huntington. Electro- and thermomigration in metals. In: Seminar of the American Society of Metals, 1972: 155-184.
[63] H.B. Huntington. Effect of driving forces on atom motion. Thin Solid Films, 1975, 25(2): 265-280
[64] D.A. Golopentia, H. B. Huntington. A study of electromigration of nickel in lead. J. Phys. Chem. Solids, 1978, 39(9): 975-984
[65] T.W. Duryea, H.B. Huntington. The driving force for electromigration of an atom adsorbed on simple metal surface. Surface Science, 1988, 199(1/2): 261-281
[66] A. Blech and C. Herring. Stress generation by electromigration. Appl. Phys. Lett., 1976, 29(3): 131-133
[67] Wei and Chih Chen. Critical length of electromigration for eutectic SnPb solder stripe. Appl. Phys. Lett., 2006, 88, 182105
[68] R. Kircheim. Stress and electromigration in al-lines of integrated-circuits. Acta Metall. Mater. 1992, 40(2): 309-323.
[69] De Munari, F. Speroni, M. Reverberi, et al. Design of a test structure to evaluateelectro-thermomigration in power ICs. Microelectronics Reliability, 1996, 36(11/12): 1875-1878
[70] Q. T. Huynh, C. Y. Liu, Chih Chen, et al. Electromigration in eutectic SnPb solder lines. J. Appl. Phys., 2001, 89(8): 4332-4335
[71] T.Y. Lee, K.N. Tu. Electromigration of eutectic SnPb solder interconnects for flip chip technology. J. Appl. Phys., 2001, 89(6): 3189-3194
[72] T. Y. Lee, K. N. Tu and D. R. Frear. Electromigration of eutectic SnPb and SnAg3.8Cu0.7 flip chip solder bumps and under-bump metallization. J. Appl. Phys., 2001, 90(9): 4502-4508
[73] Hua Ye, Cemal Basaran, Douglas C. Hopkins. Damage mechanics of microelectronics solder joints under high current densities. International Journal of Solids and Structures, 2003, 40(15): 4021-4032
[74] C.-M. Chen, S.-W. Chen. Electromigration effect upon the Sn/Ag and Sn/Ni interfacial reactions at various temperatures. Acta Materialia, 2002, 50(9): 2461-2469
[75] Brook Chao, Seung-Hyun Chae, Xuefeng Zhang, et al. Investigation of diffusion and electromigration parameters for Cu-Sn intermetallic compounds in Pb-free solders using simulated annealing. Acta Materialia, 2007, 55(8): 2805-2814
[76] J.R. Black. Physics of electromigraion. In: IEEE 12th Reliability Physics Symposium, 1983: 142-149
[77] S. Brandenburg, S. Yeh. Electromigration studies of flip chip bump solder joints. In: Processing of the Surface mount International Conference and Exposition. San Jose, CA, USA, SMATA, Edina, MN, USA, 1998: 337-344
[78] W. J. Choi, E. C. C. Yeh, and K. N. Tu. Mean-time-to-failure study of flip chip solder joints on Cu/Ni(V)/Al thin-film under-bump-metallization. J. Appl. Phys., 2003, 94(9): 5665-5671
[79] J.D. Wu, P.J. Zheng, C.W. Lee, et al. A study in flip-chip UBM/bump reliability with effects of SnPb solder composition. Microelectronics Reliability, 2006, 46(1): 41-52
[80] Yi-Shao Lai, Kuo-Ming Chen, Chin-Li Kao, et al. Electromigration of Sn-37Pb and Sn-3Ag-1.5Cu/Sn-3Ag-0.5Cu composite flip-chip solder bumps with Ti/Ni(V)/Cu under bump metallurgy. Microelectronics Reliability, 2007, 47(8): 1273-1279
[81] Y L Lin, Y S Lai, C M Tsai, et al. Effect of Surface Finish on the Failure Mechanisms of Flip-Chip Solder Joints under Electromigration. Journal of Electronic Materials, 2006, 35(12): 2147-2153
[82] Kuo Ning Chiang, Chien Chen Lee, Chang Chun Lee, et al. Current crowding-induced electromigration in SnAg3.0Cu0.5 microbumps. Appl. Phys. Lett., 2006, 88: 072102
[83] Cemal Basaran, Minghui Lin. Damage mechanics of electromigration induced failure. Mechanics of Materials, 2008, 40(1/2): 66-79
[84] C. Y. Liu, Chih Chen, and K. N. Tu. Electromigration in Sn-Pb solder strips as a function of alloy composition. J. Appl. Phys., 2000, 88(10): 5703-5709
[85] Dae-Gon Kim, Won-Chul Moon, Seung-Boo Jung. Effects of electromigration on microstructural evolution of eutectic SnPb flip chip solder bumps. Microelectronic Engineering, 2006, 83(11/12): 2391-2395
[86] Hua Ye, Cemal Basaran, Douglas C. Hopkins. Pb phase coarsening in eutectic Pb/Sn flip chip solder joints under electric current stressing. International Journal of Solids and Structures, 2004, 41(9/10): 2743-2755
[87] Jae-Woong Nah, Jong Hoon Kim, Hyuck Mo Lee, et al. Electromigration in flip chip solder bump of 97Pb-3Sn/37Pb-63Sn combination structure. Acta Materialia, 2004, 52(1): 129-136
[88] J. W. Nah, J. O. Suh, and K. N. Tu. Effect of current crowding and Joule heating on electromigration-induced failure in flip chip composite solder joints tested at room temperature. J. Appl. Phys., 2005, 98: 013715
[89] Chih-ming Chen and Sinn-wen Chen. Electromigration effect upon the Sn-0.7wt% Cu/Ni and Sn-3.5wt% Ag/Ni interfacial reactions. J. Appl. Phys., 2001, 90(3): 1208-1214
[90] Mei-yau Du, Chih-ming Chen, Sinn-wen Chen. Effects upon interfacial reactions by electric currents of reversing directions. Materials Chemistry and Physics, 2003, 82(3): 818-825
[91] Kumar, M. He, Z. Chen, P.S. Teo. Effect of electromigration on interfacial reactions between electroless Ni-P and Sn-3.5% Ag solder. Thin Solid Films, 2004, 462-463(9): 413- 418
[92] X.F. Zhang, J.D. Guo, and J.K. Shang. Abnormal polarity effect of electromigrationon intermetallic compound formation in Sn-9Zn solder interconnect. Scripta Materialia, 2007, 57(6): 513-516
[93] K.N. Tu. Recent advances on electromigration in very-large-scale-integration of interconnect. J. Appl. Phys., 2003, 94(9): 5451-5473
[94] K.N. Tu, A.M. Gusak, and M. Li. Physics and materials challenges for lead-free solders. J. Appl. Phys., 2003, 93(3): 1335-1353
[95] Lingyun Zhang, Shengquan Ou, Joanne Huang, et al. Effect of current crowding on void propagation at the interface between intermetallic compound and solder in flip chip solder joints. Appl. Phys. Lett., 2006, 88: 012106
[96] H. Gan, K.N. Tu. Polarity effect of electromigration on kinetics of intermetallic compound formation in Pb-free solder V-groove samples. J. Appl. Phys., 2005, 97: 063514
[97] Everett C. C. Yeh and K. N. Tu. Numerical simulation of current crowding phenomena and their effects on electromigration in very large scale integration interconnects. J. Appl. Phys., 2000, 88(10): 5680-5686
[98] Everett C. C. Yeh, W. J. Choi, and K. N. Tu. Current-crowding-induced electromigration failure in flip chip solder joints. Appl. Phys. Lett., 2002, 80(4): 580-582
[99] T. L. Shao, S. W. Liang, T. C. Lin, et al. Three-dimensional simulation on current-density distribution in flip-chip solder joints under electric current stressing. J. Appl. Phys., 2005, 98: 044509
[100] Yi-Shao Lai, Chin-Li Kao. Characteristics of current crowding in flip-chip solder bumps. Microelectronics Reliability, 2006, 46(5/6): 915-922
[101] Yi-Shao Lai; Chin-Li Kao. Calibration of Electromigration Reliability of Flip-Chip Packages by Electrothermal Coupling Analysis. Journal of Electronic Materials, 2006, 35(5): 972-977
[102] T. L. Shao, Y. H. Chen, S. H. Chiu, et al. Electromigration failure mechanisms for SnAg3.5 solder bumps on Ti/Cr-Cu/Cu and Ni.P./Au metallization pads. J. Appl. Phys., 2004, 96(8): 4518-4524
[103] Y H Lin, C M Tsai, Y C Hu, et al. Electromigration-Induced Failure in Flip-Chip Solder Joints. Journal of Electronic Materials, 2005, 34(1): 27-33
[104] T Hasegawa, M Saka, Y Watanabe. Direct Measurement of Local SurfaceTemperature of Eutectic Solder for Determining Electromigration Pattern. Journal of Electronic Materials, 2006, 35(5): 1074-1081
[105] Yi-Shao Lai, Chin-Li Kao. Electrothermal coupling analysis of current crowding and Joule heating in flip-chip packages. Microelectronics Reliability, 2006, 46(8): 1357-1368
[106] J.S. Zhang, Y.C. Chan, Y.P. Wu, et al. Electromigration of Pb-free solder under a low level of current density. Journal of Alloys and Compounds, 2009, 458(1/2): 492-499
[107] S. W. Liang, Y. W. Chang, T. L. Shao, et al. Effect of three-dimensional current and temperature distributions on void formation and propagation in flip-chip solder joints during electromigration. Appl. Phys. Lett., 2006, 89: 022117
[108] C Y Hsu, D J Yao, S W Liang, et al. Temperature and Current-Density Distributions in Flip-Chip Solder Joints with Cu Trace. Journal of Electronic Materials, 2006, 35(5): 947-953
[109] Fan-Yi Ouyang, K. N. Tu, Chin-Li Kao, et al. Effect of electromigration in the anodic Al interconnect on melting of flip chip solder joints. Appl. Phys. Lett., 2007, 90: 211914 2007
[110] Hua Ye, Douglas C. Hopkins, Cemal Basaran. Measurement of high electrical current density effects in solder joints. Microelectronics Reliability, 2003, 43(12): 2021-2029
[111] Hua Ye, Cemal Basaran, Douglas C. Hopkins. Deformation of solder joint under current stressing and numerical simulation - I. International Journal of Solids and Structures, 2004, 41(18/19): 4939-4958
[112] Hua Ye, Cemal Basaran, Douglas C. Hopkins. Deformation of solder joint under current stressing and numerical simulation - II. International Journal of Solids and Structures, 2004, 41: 4959-4973
[113] Paul S. Ho, Guotao Wang, Min Ding, et al. Reliability issues for flip-chip packages. Microelectronics Reliability, 2004, 44(5): 719-737
[114] Cemal Basaran, Minghui Lin, Hua Ye. A thermodynamic model for electrical current induced damage. International Journal of Solids and Structures, 2003, 40(26): 7315-7327
[115] Minghui Lin, Cemal Basaran. Electromigration induced stress analysis using fullycoupled mechanical - diffusion equations with nonlinear material properties. Computational Materials Science, 2005, 34(1): 82-98
[116] Luhua Xu, John H. L. Pang and K. N. Tu. Effect of electromigration-induced back stress gradient on nanoindentation marker movement in SnAgCu solder joints. Appl. Phys. Lett., 2006, 89: 221909
[117] Y. Liu, J. T. Chen, Y. C. Chuang, et al. Electromigration-induced Kirkendall voids at the Cu/Cu3Sn interface in flip-chip Cu/Sn/Cu joints. Appl. Phys. Lett., 2007, 90: 112114
[118] Albert T. Wu, K. N. Tu, J. R. Lloyd, et al. Electromigration-induced microstructure evolution in tin studied by synchrotron x-ray microdiffraction. Appl. Phys. Lett., 2004, 85(13): 2490-2492
[119] Albert T. Wu, A. M. Gusak, K. N. Tu, et al. Electromigration-induced grain rotation in anisotropic conducting beta tin. Phys. Lett., 2005, 86: 241902
[120] Toru Miyazaki, Tomoya Omata. Electromigration degradation mechanism for Pb-free flip-chip micro solder bumps. Microelectronics Reliability, 2006, 46(9-11): 1898-1903
[121] Luhua Xu, John H L Pang, Fei Ren, et al. Electromigration Effect on Intermetallic Growth and Young's Modulus in SAC Solder Joint. Journal of Electronic Materials, 2006, 35(12): 2116-2125
[122] Fei Ren, Jae-Woong Nah, K. N. Tu, et al. Electromigration induced ductile-to-brittle transition in lead-free solder joints. Appl. Phys. Lett., 2006, 89: 141914
[123] L. Zhang, Z.G. Wang and J.K. Shang. Current-induced weakening of Sn3.5Ag0.7Cu Pb-free solder joints. Scripta Materialia, 2007, 56(5): 381-384
[124] Test Method for Measuring Whisker Growth on Tin and Tin Alloy Surface Finishes. JESD 22A121.01. October 2005. 9, 14 (http://www.jedec.org)
[125] Environmental Acceptance Requirements for Tin Whisker Susceptibility of Tin and Tin Alloy Surface Finishes. JESD201. March 2006. 2, 12 ( http://www.jedec. org)
[126] George T. Galyon. Annotated Tin Whisker Bibliography and Anthology. IEEE Trans. Electron. Pack. Manuf., 2005, 28(1): 94-122
[127] Young's modulus, Poisson's ratio and K(Ic) at ambient temperature. (http://www. geocities.com/thaikeramos/index/young_modulus.html?20086)
[128] Methods of corrosion resistance test for metallic coatings. Japanese Industrial Association. JIS-H 8502. Japan: 1999
[129] Hua Ye, Cemal Basaran, Douglas C. Hopkins, et al. Damage Mechanics of Microelectronics Solder Joints under High Current Densities. In: Proc. 54th Elec. Comp. & Tech. Conf., USA, 2004: 988-997.
[130] Cemal Basaran, H. Ye, D.C. Hopkins, et al. Flip Chip Solder Joint Failure Modes. Advanced Packaging, 2005, 14(10): 14-19
[131] C. Basaran, H. Ye, D. C. Hopkins, et al. Failure Modes of Flip Chip Solder Joints Under High Electric Current Density. Journal of Electronic Packaging, 2005, 127(2): 157-163
[132] T. Huang, A. M. Gusak, K. N. Tu, et al. Thermomigration in SnPb composite flip chip solder joints. Appl. Phys. Lett., 2006, 88: 141911-141913
[133] Y. C. Chuang and C. Y. Liu. Thermomigration in eutectic SnPb alloy. Appl. Phys. Lett., 2006, 88: 174105-174107
[134] Fan-Yi Ouyang, K. N. Tu, Yi-Shao Lai, et al. Effect of entropy production on microstructure change in eutectic SnPb flip chip solder joints by thermomigration. Appl. Phys. Lett., 2006, 89: 221906-221908
[135] L.C. Shiau, C.E. Ho and C.R.Kao. Reactions between Sn-Ag-Cu lead-free solders and the Au/Ni surface finish in advanced electronic packages. Soldering and Surface Mount Technology, 2002, 14(3): 25-29.
[136] Y. H. Lin, C. M. Tsai, Y. C. Hu, et al. Local Melting Induced by Electromigration in Flip-Chip Solder Joints. Journal of Electronic Materials, 2006, 35(5): 1005-1009.
[137] Y.S. Lai, C.W. Lee, Y.T. Chiu, et al. Electromigration of 96.5Sn-3Ag-0.5Cu Flip-chip Solder Bumps Bonded on Substrate Pads of Au/Ni/Cu or Cu Metallization. In: Proc. 56th Elec. Comp. & Tech. Conf., USA, 2006: 641-645
[138] K S. Kim, S. H. Huh and K. Suganuma. Effects of intermetallic compounds on properties of Sn-Ag-Cu lead-free solderd joints. J. Alloy. Comd., 2003, 352(1/2): 226-236
[139] T. L. Shao, I. H. Chen and Chih Chen. Electromigration Failure Mechanism of Sn96.5Ag3.5 Flip-Chip Solder Bumps. In: Proc. 54th Elec. Comp. & Tech. Conf., USA, 2004: 979-982
[140] T. Laurila, V. Vuorinen and J.K. Kivilahti. Interfacial reactions between lead-free solders and common base materials. Materials Science and Engineering R, 2005, 49(1/2): 1-60.
[141] E. L. Paul, A. Victor. Handbook of Industrial Mixing: Science and Practice. Hoboken, NJ, USA: John Wiley & Sons Incorporated, 2004. Chapter 14 -- Heat Transfer: 869-886
[142] Database for Solder Properties with Emphasis on New Lead-free Solders. Release 4.0, 2003 (http://www.boulder.nist.gov/div853/lead%20free/props01.html)
[143] Paul Shewmon. Diffusion in solids. Second Edition, Warrendale Pennsylvania, USA: The Minerals, Metals & Materials Society, 1989. Chapter 4 -- Diffusion in a Concentration Gradient: 132-190
[144] Khosla A, Huntington HB. Electromigration in tin single crystals. J. Phys. Chem. Solids, 1975, 36(5): 395-399
[145] Hsiang-Yao Hsiao and Chih Chen. Thermomigration in flip-chip SnPb solder joints under alternating current stressing. Appl. Phys. Lett., 2007, 90: 152105-152107
[146] Dan Yang, B. Y. Wu, Y. C. Chan, et al. Microstructural evolution and atomic transport by thermomigration in eutectic tin-lead flip chip solder joints. Appl. Phys. Lett., 2007, 102: 043502-043507
[147] Chih-ming Chen and Sinn-wen Chen. Electromigration effect upon the Sn-0.7 wt% Cu/Ni and Sn-3.5 wt% Ag/Ni interfacial reactions. J. Appl. Phys., 2001, 90(3): 1208-1214
[148] Brook Chao, Seung-Hyun Chae, Xuefeng Zhang, et al. Investigation of diffusion and electromigration parameters for Cu–Sn intermetallic compounds in Pb-free solders using simulated annealing. Acta Materialia, 2007, 55(8): 2805-2814
[2] Brusse, G. Ewell, and J. Siplon. Tin Whiskers: Attributes and Mitigation. In: Capacitor and Resistor Technology Symposium (CARTS 02). New Orleans, USA, March 25-29, 2002
[3] Basic Informations Regarding Tin Whiskers. NASA Goddard Space Flight Center. (http://nepp.nasa.gov/whisker/background/index.htm#q3)
[4] iNEMI Recommendations on Lead-Free Finishes for Components Used in High-Reliability Products Version 4 (12-1-06). (http://thor.inemi.org) 2-3
[5] Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment Regulations. RoHS, 2005 (http://www.netregs.gov.uk/netregs/legislation /380525/477158/)
[6] M.O. Peach. Mechanism of Growth of Whiskers on Cadmium. J. Appl. Phys.(letters to the editor), 1952, 23(12): 1401-1403
[7] S.E. Koonce and S.M. Arnold, .Growth of Metal Whiskers. J. Appl. Phys.(letters to the editor), 1953, 24(3): 365-366
[8] F.C. Frank. On Tin Whiskers. Phil. Mag., XLIV (7). 1953: 854-860
[9] J.D. Eshelby. A Tentative Theory of Metallic Whisker Growth. Phys. Rev. 1953, 91: 755-756
[10] J. Franks. Growth of Whiskers in the Solid Phase. Acta Metallurgica, 1958, 6(2): 103-109
[11] S. Amelinckx, W. Bontinck, W. Dekeyser, et al. On the Formation and Properties of Helical Dislocations. Phil. Mag., Ser. 8th Ser., 1957, 2(15): 355-377
[12] G.S. Baker. Angular Bends in Whiskers. Acta Metallurgica, 1957, 5(7): 353-357
[13] W.C. Ellis, D.F. Gibbons, R.C. Treuting. Growth of Metal Whiskers from the Solid. Growth and Perfection of Crystals. Edited by R.H. Doremus, B.W. Roberts, and D. Turnbull, New York: John Wiley & Sons, 1958: 102-120
[14] V.K. Glazunova and N.T. Kudryavtsev. An Investigation of the Conditions of Spontaneous Growth of Filiform Crystals on Electrolytic Coatings. Translated fromZhurnal Prikladnoi Khimii, 1963, 36(3): 543-550
[15] T. Kakeshita, K. Shimizu, R. Kawanaka, et al. Grain size effect on electroplated tin coatings on whisker growth. J. Mater. Sci., 1982, 17(9): 2560-2566
[16] J. B. LeBret and M. G. Norton. Electron microscopy study of tin whisker growth. J. Mater. Res., 2003, 18(2): 585-593
[17] Boguslavsky and P. Bush. Recrystallization principles applied to whisker growth in tin. In: Proc. APEX Conf., Anaheim, CA, 2003: S12-4-1–S12-4-10
[18] K.N. Tu. Irreversible Processes of Spontaneous Whisker Growth in Bimetallic Cu-Sn Thin Reactions. Phys. Rev. B, 1994, 49(3): 2030-2034
[19] R.M. Fisher, L.S. Darken, and K.G. Carroll. Accelerated Growth of Tin Whiskers. Acta Metallurgica. 1954, 2(3): 368-372
[20] R.R Hasiguti. A Tentative Explanation of the Accelerated Growth of Tin Whiskers. Acta Metallurgica (letters to the editor), 1955, 3(2): 200-201
[21] B.Z. Lee and D.N. Lee. Spontaneous Growth Mechanism of Tin Whiskers. Acta Metallurgica, 1998, 46(10): 3701-3714
[22] Y. Zhang, C. Xu, C. Fan, et al. Understanding Whisker Phenomenon-Part I: Growth Rates. In: Proc. of the 2001 AESF SUR/FIN Conf., UAS, 2001: NA
[23] C. Xu, C. Fan, A. Vysotskova, et al. Understanding Whisker Phenomenon-Part II, Competitive Mechanisms. In: Proc. of the 2001 AESF SUR/FIN Conf., USA, 2001: NA
[24] Y. Zhang, C. Xu, C. Fan, et al. Understanding Whisker Phenomenon: Whisker Index and Tin/Copper, Tin/Nickel Interface. In: Proc. IPC SMEMA APEX Conf., 2002, S-06-1-1~10
[25] C. Xu, Y. Zhang, C. Fan, et al. Understanding Whisker Phenomenon Driving Forces for the Whisker Formation. In: Proc. IPC SMEMA APEX Conf., 2002: S-06-2-1~6
[26] K.N. Tu. Inter-diffusion and Reaction in Bimetallic Cu-Sn Thin Films. Acta Metallurgica, 1973, 21(4): 347-354
[27] Egli, W. Zhang, J. Heber, et al. Where Crystal Planes Meet: Contribution to the Understanding of the Whisker Growth Process. In: IPC Annual Meeting, USA, 2002: S08-3-1~5
[28] W.J. Choi, T.Y. Lee, and K.N. Tu. Structure and Kinetics of Sn Whisker Growth on Pb-free Solder Finish. In: Proc. 52nd Elec. Comp. & Tech. Conf., USA, 2002:628-633
[29] W.J. Choi, T.Y. Lee, K.N. Tu, et al. Tin Whiskers Studied by Synchrotron Radiation Scanning X-ray Micro-Diffraction. Acta Materialia, 2003, 51(20): 6253-6262
[30] G.T.T. Sheng, C.F. Hu, W.J. Choi, et al. Tin Whiskers Studied by Focused Ion Beam Imaging and Transmission Electron Microscopy. J. Appl. Phys., 2002, 92(1): 64-69
[31] J. Chang-Bing Lee, Y-L.Yao, F-Y. Chiang, et al. Characterization Study of Lead-free SnCu Plated Packages. In: Proc. IEEE Elect. Comp. & Tech. Conf., USA, 2002: 1238-1245
[32] K.N. Tu and K. Zeng. Reliability Issues of Pb-free Solder Joints in Electronic Packaging Technology. In: Proc. IEEE Elect. Comp. & Tech. Conf., USA, 2002: 1194-1199
[33] S.M. Arnold. Repressing growth of tin whiskers. Plating PLATA, 1966, 53: 96-99
[34] S.C. Britton. Spontaneous Growth of Whiskers on Tin Coatings: 20 Years of Observation. Trans. of the Institute of Metal Finishing, 1974, 52: 95-102
[35] M. W. Barsoum, E. N. Hoffman, R. D. Doherty, et al. Driving force and mechanism for spontaneous metal whisker formation. Phys. Rev. Lett., 2004, 93(20): 206104-1~4
[36] P. Oberndorff, M. Dittes, P. Crema, et al. Whisker formation on matte Sn influencing of high humidity. In: Proc. 55th Electron. Compon. Technol. Conf., USA, 2005: 429-433.
[37] J W Osenbach, J M DeLucca, B D Potteiger, et al. Sn corrosion and its influence on whiskers. IEEE T. Electron. Pack., 2007, 30(1): 23-35
[38] M. Dittes, P. Oberndorff, P. Crema, et al. The Effect of Temperature cycling on Tin Whisker Formation. In: The Proc. of the IPC-Jedec Conf.-Frankfort, 2003: NA
[39] S. Madra. Thermo-Mechanical Characterization of Lead-Free Tin Plating: X-Ray Diffraction Measurements and Correlation with Analytical and Numerical Models. In: Proc. of the PC-Jedec Conf.-Frankfort, 2003: NA
[40] S.M. Arnold. The Growth of Metal Whiskers on Electrical Components. In: Proc. of the IEEE Elec. Comp. Conf., 1959: 75-82
[41] B.D. Dunn. Metallurgy and Reliability in Spacecraft Electronics. Metals and Materials, 1975, 34(3): 32-40
[42] B.D. Dunn. Whisker Formation on Electronic Materials. Circuit World, 1976, 2(4): 32-40
[43] Yanada. Electroplating of Lead-Free Solder Alloys Composed of Sn-Bi and Sn-Ag. In: Proc. of the IPC Printed Circuits Expo, USA, 1998: S-11-2~7
[44] R. Schetty. Minimization of Tin Whisker Formation for Lead-Free Electronics Finishing. In: Proc. of the IPC Works Conf., USA, 2000: S-02-R3-1~6
[45] R. Schetty, N. Brown, A. Egli, et al. Lead-Free Finishes-Whisker Studies and Practical Methods for Minimizing the Risk of Whisker Growth. In: Proc. of the AESF SUR/FIN Conf., USA, 2001: 1-5
[46] D. Hillman. JCAA/ JG-PP No-Lead Solder Project: -20°C to +80°C & -55°C to +125°C Thermal Cycle Testing. In: SMTA International Conference Proceedings, 2005: 846-850
[47] J. Bradford, J. Felty and B. Russell. JCAA/ JG-PP No-Lead Solder Project: Combined Environments Test. In: SMTA International Conference Proceedings, 2005: 824-840
[48] G.J. Ewell and F. Moore. Tin Whiskers and Passive Components: A Review of the Concerns. In: Proc. of the 18th Conference on Capacitor and Resistor Technology, CARTS, 1998: 222-228
[49] M. Dittes, P.Oberndorff and L.Petit. Tin Whisker Formation - Results, Test Methods and Countermeasures. In: Proc 53rd Elec. Comp. & Tech. Conf., USA, 2003: 822-826
[50] W.K. Choi, S.K. Kang, Y.C. Sohn, et al. Study of IMC Morphologies and Phase Characteristics Affected by the Reactions of Ni and Cu Metallurgies with Pb-Free Solder Joints. In: Proc. 53rd Elec. Comp. & Tech. Conf., USA, 2003: 1190-1196
[51] J.W. Osenbach, R.L. Shook, B.T. Vaccaro, et al. Tin Whisker Mitigation: Application of Post Mold Nickel Underplate on Copper Based Lead Frames and Effects of Board Assembly Reflow. In: Proc. Surf. Mount Tech. Assoc., 2004: 724-734
[52] M. Osterman. Mitigation Strategies for Tin Whiskers. (http://www.calce.umd.edu/ lead-free/tin-whiskers/TINWHISKERMITIGATION.pdf).
[53] K.W. Moon, M.E. Williams, C.E. Johnson, et al. The Formation of Whiskers on Electroplated Tin Containing Copper. In: Proc. 4th Pacific Rim Inter. Conf. onAdvanced Materials and Processing, Japan, 2001: 1115-1118
[54] M.E. Williams, C.E. Johnson, K.W. Moon, et al. Whisker Formation on Electroplated SnCu. In: Proc. of AESF SUR/FIN Conf., 2002: 31-39
[55] Valeska Schroeder, Peter Bush, Maureen Williams, et al. Tin Whisker Test Method Development. In: IEEE Trans. Electron. Pack. Manuf., 2006, 29(4): 231-238.
[56] Oberndorff P., Dittes M., Crema P. Tin whisker formation in thermal cycling conditions. In: Proc. 53rd Elec. Comp. & Tech. Conf., USA, 2003: 183-188
[57] H. B. Huntington and A. R. Grone. Current-induced marker motion in gold wires. J. Phys. Chem. Solids 1961, 20(1/2): 76-87
[58] Aris Christou. Electromigration and electronic device degradation. 1st Edition. Canada: John Wiley & Sons, Inc., 1994: 1-46
[59] International Roadmap for Semiconductor Technology. Semiconductor Industry Association, 1999
[60] P.S. Ho, H.B. Huntington. Electromigration and void observation in silver. J. Phys. Chem. Solids, 1966, 27(8): 1319-1329
[61] J.F. D’amico, H.B. Huntington. Electromigration and thermomigration in Gamma-uranium. J. Phys. Chem. Solids, 1969, 30(11): 2607-2621
[62] H.B. Huntington. Electro- and thermomigration in metals. In: Seminar of the American Society of Metals, 1972: 155-184.
[63] H.B. Huntington. Effect of driving forces on atom motion. Thin Solid Films, 1975, 25(2): 265-280
[64] D.A. Golopentia, H. B. Huntington. A study of electromigration of nickel in lead. J. Phys. Chem. Solids, 1978, 39(9): 975-984
[65] T.W. Duryea, H.B. Huntington. The driving force for electromigration of an atom adsorbed on simple metal surface. Surface Science, 1988, 199(1/2): 261-281
[66] A. Blech and C. Herring. Stress generation by electromigration. Appl. Phys. Lett., 1976, 29(3): 131-133
[67] Wei and Chih Chen. Critical length of electromigration for eutectic SnPb solder stripe. Appl. Phys. Lett., 2006, 88, 182105
[68] R. Kircheim. Stress and electromigration in al-lines of integrated-circuits. Acta Metall. Mater. 1992, 40(2): 309-323.
[69] De Munari, F. Speroni, M. Reverberi, et al. Design of a test structure to evaluateelectro-thermomigration in power ICs. Microelectronics Reliability, 1996, 36(11/12): 1875-1878
[70] Q. T. Huynh, C. Y. Liu, Chih Chen, et al. Electromigration in eutectic SnPb solder lines. J. Appl. Phys., 2001, 89(8): 4332-4335
[71] T.Y. Lee, K.N. Tu. Electromigration of eutectic SnPb solder interconnects for flip chip technology. J. Appl. Phys., 2001, 89(6): 3189-3194
[72] T. Y. Lee, K. N. Tu and D. R. Frear. Electromigration of eutectic SnPb and SnAg3.8Cu0.7 flip chip solder bumps and under-bump metallization. J. Appl. Phys., 2001, 90(9): 4502-4508
[73] Hua Ye, Cemal Basaran, Douglas C. Hopkins. Damage mechanics of microelectronics solder joints under high current densities. International Journal of Solids and Structures, 2003, 40(15): 4021-4032
[74] C.-M. Chen, S.-W. Chen. Electromigration effect upon the Sn/Ag and Sn/Ni interfacial reactions at various temperatures. Acta Materialia, 2002, 50(9): 2461-2469
[75] Brook Chao, Seung-Hyun Chae, Xuefeng Zhang, et al. Investigation of diffusion and electromigration parameters for Cu-Sn intermetallic compounds in Pb-free solders using simulated annealing. Acta Materialia, 2007, 55(8): 2805-2814
[76] J.R. Black. Physics of electromigraion. In: IEEE 12th Reliability Physics Symposium, 1983: 142-149
[77] S. Brandenburg, S. Yeh. Electromigration studies of flip chip bump solder joints. In: Processing of the Surface mount International Conference and Exposition. San Jose, CA, USA, SMATA, Edina, MN, USA, 1998: 337-344
[78] W. J. Choi, E. C. C. Yeh, and K. N. Tu. Mean-time-to-failure study of flip chip solder joints on Cu/Ni(V)/Al thin-film under-bump-metallization. J. Appl. Phys., 2003, 94(9): 5665-5671
[79] J.D. Wu, P.J. Zheng, C.W. Lee, et al. A study in flip-chip UBM/bump reliability with effects of SnPb solder composition. Microelectronics Reliability, 2006, 46(1): 41-52
[80] Yi-Shao Lai, Kuo-Ming Chen, Chin-Li Kao, et al. Electromigration of Sn-37Pb and Sn-3Ag-1.5Cu/Sn-3Ag-0.5Cu composite flip-chip solder bumps with Ti/Ni(V)/Cu under bump metallurgy. Microelectronics Reliability, 2007, 47(8): 1273-1279
[81] Y L Lin, Y S Lai, C M Tsai, et al. Effect of Surface Finish on the Failure Mechanisms of Flip-Chip Solder Joints under Electromigration. Journal of Electronic Materials, 2006, 35(12): 2147-2153
[82] Kuo Ning Chiang, Chien Chen Lee, Chang Chun Lee, et al. Current crowding-induced electromigration in SnAg3.0Cu0.5 microbumps. Appl. Phys. Lett., 2006, 88: 072102
[83] Cemal Basaran, Minghui Lin. Damage mechanics of electromigration induced failure. Mechanics of Materials, 2008, 40(1/2): 66-79
[84] C. Y. Liu, Chih Chen, and K. N. Tu. Electromigration in Sn-Pb solder strips as a function of alloy composition. J. Appl. Phys., 2000, 88(10): 5703-5709
[85] Dae-Gon Kim, Won-Chul Moon, Seung-Boo Jung. Effects of electromigration on microstructural evolution of eutectic SnPb flip chip solder bumps. Microelectronic Engineering, 2006, 83(11/12): 2391-2395
[86] Hua Ye, Cemal Basaran, Douglas C. Hopkins. Pb phase coarsening in eutectic Pb/Sn flip chip solder joints under electric current stressing. International Journal of Solids and Structures, 2004, 41(9/10): 2743-2755
[87] Jae-Woong Nah, Jong Hoon Kim, Hyuck Mo Lee, et al. Electromigration in flip chip solder bump of 97Pb-3Sn/37Pb-63Sn combination structure. Acta Materialia, 2004, 52(1): 129-136
[88] J. W. Nah, J. O. Suh, and K. N. Tu. Effect of current crowding and Joule heating on electromigration-induced failure in flip chip composite solder joints tested at room temperature. J. Appl. Phys., 2005, 98: 013715
[89] Chih-ming Chen and Sinn-wen Chen. Electromigration effect upon the Sn-0.7wt% Cu/Ni and Sn-3.5wt% Ag/Ni interfacial reactions. J. Appl. Phys., 2001, 90(3): 1208-1214
[90] Mei-yau Du, Chih-ming Chen, Sinn-wen Chen. Effects upon interfacial reactions by electric currents of reversing directions. Materials Chemistry and Physics, 2003, 82(3): 818-825
[91] Kumar, M. He, Z. Chen, P.S. Teo. Effect of electromigration on interfacial reactions between electroless Ni-P and Sn-3.5% Ag solder. Thin Solid Films, 2004, 462-463(9): 413- 418
[92] X.F. Zhang, J.D. Guo, and J.K. Shang. Abnormal polarity effect of electromigrationon intermetallic compound formation in Sn-9Zn solder interconnect. Scripta Materialia, 2007, 57(6): 513-516
[93] K.N. Tu. Recent advances on electromigration in very-large-scale-integration of interconnect. J. Appl. Phys., 2003, 94(9): 5451-5473
[94] K.N. Tu, A.M. Gusak, and M. Li. Physics and materials challenges for lead-free solders. J. Appl. Phys., 2003, 93(3): 1335-1353
[95] Lingyun Zhang, Shengquan Ou, Joanne Huang, et al. Effect of current crowding on void propagation at the interface between intermetallic compound and solder in flip chip solder joints. Appl. Phys. Lett., 2006, 88: 012106
[96] H. Gan, K.N. Tu. Polarity effect of electromigration on kinetics of intermetallic compound formation in Pb-free solder V-groove samples. J. Appl. Phys., 2005, 97: 063514
[97] Everett C. C. Yeh and K. N. Tu. Numerical simulation of current crowding phenomena and their effects on electromigration in very large scale integration interconnects. J. Appl. Phys., 2000, 88(10): 5680-5686
[98] Everett C. C. Yeh, W. J. Choi, and K. N. Tu. Current-crowding-induced electromigration failure in flip chip solder joints. Appl. Phys. Lett., 2002, 80(4): 580-582
[99] T. L. Shao, S. W. Liang, T. C. Lin, et al. Three-dimensional simulation on current-density distribution in flip-chip solder joints under electric current stressing. J. Appl. Phys., 2005, 98: 044509
[100] Yi-Shao Lai, Chin-Li Kao. Characteristics of current crowding in flip-chip solder bumps. Microelectronics Reliability, 2006, 46(5/6): 915-922
[101] Yi-Shao Lai; Chin-Li Kao. Calibration of Electromigration Reliability of Flip-Chip Packages by Electrothermal Coupling Analysis. Journal of Electronic Materials, 2006, 35(5): 972-977
[102] T. L. Shao, Y. H. Chen, S. H. Chiu, et al. Electromigration failure mechanisms for SnAg3.5 solder bumps on Ti/Cr-Cu/Cu and Ni.P./Au metallization pads. J. Appl. Phys., 2004, 96(8): 4518-4524
[103] Y H Lin, C M Tsai, Y C Hu, et al. Electromigration-Induced Failure in Flip-Chip Solder Joints. Journal of Electronic Materials, 2005, 34(1): 27-33
[104] T Hasegawa, M Saka, Y Watanabe. Direct Measurement of Local SurfaceTemperature of Eutectic Solder for Determining Electromigration Pattern. Journal of Electronic Materials, 2006, 35(5): 1074-1081
[105] Yi-Shao Lai, Chin-Li Kao. Electrothermal coupling analysis of current crowding and Joule heating in flip-chip packages. Microelectronics Reliability, 2006, 46(8): 1357-1368
[106] J.S. Zhang, Y.C. Chan, Y.P. Wu, et al. Electromigration of Pb-free solder under a low level of current density. Journal of Alloys and Compounds, 2009, 458(1/2): 492-499
[107] S. W. Liang, Y. W. Chang, T. L. Shao, et al. Effect of three-dimensional current and temperature distributions on void formation and propagation in flip-chip solder joints during electromigration. Appl. Phys. Lett., 2006, 89: 022117
[108] C Y Hsu, D J Yao, S W Liang, et al. Temperature and Current-Density Distributions in Flip-Chip Solder Joints with Cu Trace. Journal of Electronic Materials, 2006, 35(5): 947-953
[109] Fan-Yi Ouyang, K. N. Tu, Chin-Li Kao, et al. Effect of electromigration in the anodic Al interconnect on melting of flip chip solder joints. Appl. Phys. Lett., 2007, 90: 211914 2007
[110] Hua Ye, Douglas C. Hopkins, Cemal Basaran. Measurement of high electrical current density effects in solder joints. Microelectronics Reliability, 2003, 43(12): 2021-2029
[111] Hua Ye, Cemal Basaran, Douglas C. Hopkins. Deformation of solder joint under current stressing and numerical simulation - I. International Journal of Solids and Structures, 2004, 41(18/19): 4939-4958
[112] Hua Ye, Cemal Basaran, Douglas C. Hopkins. Deformation of solder joint under current stressing and numerical simulation - II. International Journal of Solids and Structures, 2004, 41: 4959-4973
[113] Paul S. Ho, Guotao Wang, Min Ding, et al. Reliability issues for flip-chip packages. Microelectronics Reliability, 2004, 44(5): 719-737
[114] Cemal Basaran, Minghui Lin, Hua Ye. A thermodynamic model for electrical current induced damage. International Journal of Solids and Structures, 2003, 40(26): 7315-7327
[115] Minghui Lin, Cemal Basaran. Electromigration induced stress analysis using fullycoupled mechanical - diffusion equations with nonlinear material properties. Computational Materials Science, 2005, 34(1): 82-98
[116] Luhua Xu, John H. L. Pang and K. N. Tu. Effect of electromigration-induced back stress gradient on nanoindentation marker movement in SnAgCu solder joints. Appl. Phys. Lett., 2006, 89: 221909
[117] Y. Liu, J. T. Chen, Y. C. Chuang, et al. Electromigration-induced Kirkendall voids at the Cu/Cu3Sn interface in flip-chip Cu/Sn/Cu joints. Appl. Phys. Lett., 2007, 90: 112114
[118] Albert T. Wu, K. N. Tu, J. R. Lloyd, et al. Electromigration-induced microstructure evolution in tin studied by synchrotron x-ray microdiffraction. Appl. Phys. Lett., 2004, 85(13): 2490-2492
[119] Albert T. Wu, A. M. Gusak, K. N. Tu, et al. Electromigration-induced grain rotation in anisotropic conducting beta tin. Phys. Lett., 2005, 86: 241902
[120] Toru Miyazaki, Tomoya Omata. Electromigration degradation mechanism for Pb-free flip-chip micro solder bumps. Microelectronics Reliability, 2006, 46(9-11): 1898-1903
[121] Luhua Xu, John H L Pang, Fei Ren, et al. Electromigration Effect on Intermetallic Growth and Young's Modulus in SAC Solder Joint. Journal of Electronic Materials, 2006, 35(12): 2116-2125
[122] Fei Ren, Jae-Woong Nah, K. N. Tu, et al. Electromigration induced ductile-to-brittle transition in lead-free solder joints. Appl. Phys. Lett., 2006, 89: 141914
[123] L. Zhang, Z.G. Wang and J.K. Shang. Current-induced weakening of Sn3.5Ag0.7Cu Pb-free solder joints. Scripta Materialia, 2007, 56(5): 381-384
[124] Test Method for Measuring Whisker Growth on Tin and Tin Alloy Surface Finishes. JESD 22A121.01. October 2005. 9, 14 (http://www.jedec.org)
[125] Environmental Acceptance Requirements for Tin Whisker Susceptibility of Tin and Tin Alloy Surface Finishes. JESD201. March 2006. 2, 12 ( http://www.jedec. org)
[126] George T. Galyon. Annotated Tin Whisker Bibliography and Anthology. IEEE Trans. Electron. Pack. Manuf., 2005, 28(1): 94-122
[127] Young's modulus, Poisson's ratio and K(Ic) at ambient temperature. (http://www. geocities.com/thaikeramos/index/young_modulus.html?20086)
[128] Methods of corrosion resistance test for metallic coatings. Japanese Industrial Association. JIS-H 8502. Japan: 1999
[129] Hua Ye, Cemal Basaran, Douglas C. Hopkins, et al. Damage Mechanics of Microelectronics Solder Joints under High Current Densities. In: Proc. 54th Elec. Comp. & Tech. Conf., USA, 2004: 988-997.
[130] Cemal Basaran, H. Ye, D.C. Hopkins, et al. Flip Chip Solder Joint Failure Modes. Advanced Packaging, 2005, 14(10): 14-19
[131] C. Basaran, H. Ye, D. C. Hopkins, et al. Failure Modes of Flip Chip Solder Joints Under High Electric Current Density. Journal of Electronic Packaging, 2005, 127(2): 157-163
[132] T. Huang, A. M. Gusak, K. N. Tu, et al. Thermomigration in SnPb composite flip chip solder joints. Appl. Phys. Lett., 2006, 88: 141911-141913
[133] Y. C. Chuang and C. Y. Liu. Thermomigration in eutectic SnPb alloy. Appl. Phys. Lett., 2006, 88: 174105-174107
[134] Fan-Yi Ouyang, K. N. Tu, Yi-Shao Lai, et al. Effect of entropy production on microstructure change in eutectic SnPb flip chip solder joints by thermomigration. Appl. Phys. Lett., 2006, 89: 221906-221908
[135] L.C. Shiau, C.E. Ho and C.R.Kao. Reactions between Sn-Ag-Cu lead-free solders and the Au/Ni surface finish in advanced electronic packages. Soldering and Surface Mount Technology, 2002, 14(3): 25-29.
[136] Y. H. Lin, C. M. Tsai, Y. C. Hu, et al. Local Melting Induced by Electromigration in Flip-Chip Solder Joints. Journal of Electronic Materials, 2006, 35(5): 1005-1009.
[137] Y.S. Lai, C.W. Lee, Y.T. Chiu, et al. Electromigration of 96.5Sn-3Ag-0.5Cu Flip-chip Solder Bumps Bonded on Substrate Pads of Au/Ni/Cu or Cu Metallization. In: Proc. 56th Elec. Comp. & Tech. Conf., USA, 2006: 641-645
[138] K S. Kim, S. H. Huh and K. Suganuma. Effects of intermetallic compounds on properties of Sn-Ag-Cu lead-free solderd joints. J. Alloy. Comd., 2003, 352(1/2): 226-236
[139] T. L. Shao, I. H. Chen and Chih Chen. Electromigration Failure Mechanism of Sn96.5Ag3.5 Flip-Chip Solder Bumps. In: Proc. 54th Elec. Comp. & Tech. Conf., USA, 2004: 979-982
[140] T. Laurila, V. Vuorinen and J.K. Kivilahti. Interfacial reactions between lead-free solders and common base materials. Materials Science and Engineering R, 2005, 49(1/2): 1-60.
[141] E. L. Paul, A. Victor. Handbook of Industrial Mixing: Science and Practice. Hoboken, NJ, USA: John Wiley & Sons Incorporated, 2004. Chapter 14 -- Heat Transfer: 869-886
[142] Database for Solder Properties with Emphasis on New Lead-free Solders. Release 4.0, 2003 (http://www.boulder.nist.gov/div853/lead%20free/props01.html)
[143] Paul Shewmon. Diffusion in solids. Second Edition, Warrendale Pennsylvania, USA: The Minerals, Metals & Materials Society, 1989. Chapter 4 -- Diffusion in a Concentration Gradient: 132-190
[144] Khosla A, Huntington HB. Electromigration in tin single crystals. J. Phys. Chem. Solids, 1975, 36(5): 395-399
[145] Hsiang-Yao Hsiao and Chih Chen. Thermomigration in flip-chip SnPb solder joints under alternating current stressing. Appl. Phys. Lett., 2007, 90: 152105-152107
[146] Dan Yang, B. Y. Wu, Y. C. Chan, et al. Microstructural evolution and atomic transport by thermomigration in eutectic tin-lead flip chip solder joints. Appl. Phys. Lett., 2007, 102: 043502-043507
[147] Chih-ming Chen and Sinn-wen Chen. Electromigration effect upon the Sn-0.7 wt% Cu/Ni and Sn-3.5 wt% Ag/Ni interfacial reactions. J. Appl. Phys., 2001, 90(3): 1208-1214
[148] Brook Chao, Seung-Hyun Chae, Xuefeng Zhang, et al. Investigation of diffusion and electromigration parameters for Cu–Sn intermetallic compounds in Pb-free solders using simulated annealing. Acta Materialia, 2007, 55(8): 2805-2814