銀合金線材在半導體封裝產業中的使用日益普遍，本研究將商業用銀鈀銦合金線材予以通電，藉由背向電子繞射分析(EBSD)釐清材料通電後之再結晶、晶粒成長的晶界特性、晶粒取向等細部變化，並利用穿透式電子顯微鏡(TEM)觀察晶格排列及差排變化，亦進行機械性質量測。結果顯示通電導致的再結晶現象發生與否及其程度，電流密度為重要影響因素，當電流密度越高，在電遷移作用力的推動與焦耳熱的影響，驅使再結晶發生。在電流密度7×104 A/cm2 以上時，開始出現材料再結晶現象，而以8×104 A/cm2通電僅僅一分鐘即完成再結晶且出現明顯晶粒成長的現象。材料在初期晶粒成長之前主要因再結晶而產生的現象為雙晶數目大增、平均取向差增加、差排形貌改變及數量下降、應變下降；再結晶完成後若持續通電，晶粒會以不均勻的速度增長，線材中央的晶粒急速成長且併吞周圍晶粒，隨著晶粒成長，<111>：<001>晶粒取向比例增加。以6×104 A/cm2~8×104 A/cm2的電流密度通電後，材料拉伸強度呈現下降，且電流密度越高，降幅越大；延展性則是隨電流密度的增加先呈現下降而後回升。

Ag alloy wires have received more attention in the electronic packaging industry recently. In this study, Ag-Pd-In alloy wires were stressed with an electric current. The grain boundary characterization and grain orientation were investigated by Electron Backscatter Diffraction (EBSD). The lattice structures and dislocations were observed by Transmission Electron Microscopy (TEM). The results indicated that the current density is an important factor that determines the recrystallization behaviors of the alloy. Larger current density induces a larger electromigration force and Joule heat, which promote specimens to recrystallize more easily. When the specimens were subjected to the current stressing under 7×104 A/cm2, recrystallization appeared. The specimens recrystallized completely and show apparent grain growth when stressed under 8×104 A/cm2 for just one minute. The recrystallization was accompanied by an increase in twin fraction, misorientation angle, change of dislocation structure, and a reduction of dislocation density and strain during the current stressing. The grain growth rate is grain dependent. The grains in the core of the wires would grow more quickly than the exterior of the wires. The ratio of grain orientation of <111> to <001> increased with grain growth. The tensile strength of the wire degraded upon current stressing under 6×104~8×104 A/cm2. The tensile strength is disproportional to the magnitude of current density. The elongation of the wire reached a minimum value at 7×104 A/cm2 in the range of current density applied.

[1] N. Srikanth, S. Murali, Y. M. Wong, and C. J. Vath Iii, "Critical Study of Thermosonic Copper Ball Bonding," Thin Solid Films, vol. 462-463, pp. 339-345, 2004.
[2] C. D. Breach, "What Is the Future of Bonding Wire? Will Copper Entirely Replace Gold?," Gold Bulletin, journal article vol. 43, no. 3, pp. 150-168, 2010.
[3] Z. W. Zhong et al., "Study of Factors Affecting the Hardness of Ball Bonds in Copper Wire Bonding," Microelectronic Engineering, vol. 84, no. 2, pp. 368-374, 2007.
[4] P. Chauhan, Z. W. Zhong, and M. Pecht, "Copper Wire Bonding Concerns and Best Practices," Journal of Electronic Materials, journal article vol. 42, no. 8, pp. 2415-2434, 2013.
[5] P. S. Chauhan, A. Choubey, Z. Zhong, and M. G. Pecht, "Copper Wire Bonding," in Copper Wire Bonding: Springer, pp. 1-9, 2004
[6] A. Shah et al., "Advanced Wire Bonding Technology for Ag Wire," in 2015 IEEE 17th Electronics Packaging and Technology Conference (EPTC), pp. 1-8, 2015.
[7] M. Schneider-Ramelow and C. Ehrhardt, "The Reliability of Wire Bonding Using Ag and Al," Microelectronics Reliability, vol. 63, pp. 336-341, 2016.
[8] A. Lan, J. Tsai, J. Huang, and O. Hung, "Interconnection Challenge of Wire Bonding - Ag Alloy Wire," in 2013 IEEE 15th Electronics Packaging Technology Conference (EPTC), pp. 504-509, 2013.
[9] J. Tsai, A. Lan, D. S. Jiang, L. W. Wu, J. Huang, and J. B. Hong, "Ag Alloy Wire Characteristic and Benefits," in 2014 IEEE 64th Electronic Components and Technology Conference (ECTC), pp. 1533-1538, 2014.
[10] J. S. Cho et al., "Pd Effects on the Reliability in the Low Cost Ag Bonding Wire," in 2010 Proceedings 60th Electronic Components and Technology Conference (ECTC), pp. 1541-1546, 2010
[11] J. S. Cho, K. A. Yoo, J. T. Moon, S. B. Son, S. H. Lee, and K. H. Oh, "Pd Effect on Reliability of Ag Bonding Wires in Microelectronic Devices in High-Humidity Environments," Metals and Materials International, vol. 18, no. 5, pp. 881-885, 2012.
[12] K. Vu, "Silver Migration–The Mechanism and Effects on Thick-Film Conductors," Mater Sci Eng, vol. 234, pp. 1-21, 2003.
[13] C. H. Tsai et al., "Materials Characteristics of Ag-Alloy Wires and Their Applications in Advanced Packages," IEEE Transactions on Components, Packaging and Manufacturing Technology, vol. 6, no. 2, pp. 298-305, 2016.
[14] H. H. Tsai, J. D. Lee, C. H. Tsai, H. C. Wang, C. C. Chang, and T. H. Chuang, "An Innovative Annealing-Twinned Ag-Au-Pd Bonding Wire for IC and LED Packaging," in 2012 7th International Microsystems, Packaging, Assembly and Circuits Technology Conference (IMPACT), pp. 243-246, 2012.
[15] J. Xi et al., "Evaluation of Ag Wire Reliability on Fine Pitch Wire Bonding," in 2015 IEEE 65th Electronic Components and Technology Conference (ECTC), pp. 1392-1395, 2015
[16] Y. C. Jang et al., "Study of Intermetallic Compound Growth and Failure Mechanisms in Long Term Reliability of Silver Bonding Wire," in 2014 IEEE 16th Electronics Packaging Technology Conference (EPTC), pp. 704-708, 2014
[17] Y. W. Lin, M. C. Su, W. H. Huang, Y. T. Chiu, T. P. Shih, and K. L. Lin, "Effect of Doping Element on the Interfacial Reaction Behavior of Ag Alloy Wires Bonding on Al Pad after HTST and TCT Tests," in 2016 IEEE 18th Electronics Packaging Technology Conference (EPTC), pp. 613-619, 2016
[18] I. Blech, "Diffusional Back Flows during Electromigration," Acta Materialia, vol. 46, no. 11, pp. 3717-3723, 1998.
[19] J. R. Black, "Electromigration Failure Modes in Aluminum Metallization for Semiconductor Devices," Proceedings of the IEEE, vol. 57, no. 9, pp. 1587-1594, 1969.
[20] A. Scorzoni, B. Neri, C. Caprile, and F. Fantini, "Electromigration in Thin-Film Interconnection Lines: Models, Methods and Results," Materials Science Reports, vol. 7, no. 4-5, pp. 143-220, 1991.
[21] J. Cannis, "Green IC packaging," Advanced Packaging, vol. 8, pp. 33-38, 2001.
[22] H. Huntington and A. Grone, "Current-Induced Marker Motion in Gold Wires," Journal of Physics and Chemistry of Solids, vol. 20, no. 1-2, pp. 76-87, 1961.
[23] R. Brouwer and R. Griessen, "Electromigration of Hydrogen in Alloys: Evidence of Unscreened Proton Behavior," Physical review letters, vol. 62, no. 15, pp. 1760, 1989.
[24] C. M. Tan and A. Roy, "Electromigration in ULSI Interconnects," Materials Science and Engineering: R: Reports, vol. 58, no. 1–2, pp. 1-75, 2007.
[25] A. S. Nowick, "Diffusion in Solids: Recent Developments," Elsevier, 2012.
[26] R. Barabash et al., "Quantitative Analysis of Dislocation Arrangements Induced by Electromigration in a Passivated Al (0.5 wt% Cu) Interconnect," Journal of applied physics, vol. 93, no. 9, pp. 5701-5706, 2003.
[27] B. C. Valek et al., "Early Stage of Plastic Deformation in Thin Films Undergoing Electromigration," Journal of Applied Physics, vol. 94, no. 6, pp. 3757-3761, 2003.
[28] A. Budiman et al., "Crystal Plasticity in Cu Damascene Interconnect Lines Undergoing Electromigration as Revealed by Synchrotron X-ray Microdiffraction," Applied Physics Letters, vol. 88, no. 23, pp. 233515, 2006.
[29] C. N. Liao, K. C. Chen, W. W. Wu, and L. J. Chen, "In Situ Transmission Electron Microscope Observations of Electromigration in Copper Lines at Room Temperature," Applied Physics Letters, vol. 87, no. 14, pp. 141903, 2005.
[30] Y. H. Liao, C. L. Liang, K. L. Lin, and A. T. Wu, "High Dislocation Density of Tin Induced by Electric Current," AIP Advances, vol. 5, no. 12, pp. 127210, 2015.
[31] H. C. Huang, K. L. Lin, and A. T. Wu, "Disruption of Crystalline Structure of Sn3.5Ag Induced by Electric Current," Journal of Applied Physics, vol. 119, no. 11, pp. 115102, 2016.
[32] C. H. Chuang, C. H. Tsai, Y. C. Lin, and H. J. Lin, "Effects of Current Stressing on the Grain Structure and Mechanical Properties of Ag-Alloy Bonding Wires with Various Pd and Au Contents," Metals, vol. 6, no. 8, pp. 182, 2016.
[33] T. H. Chuang, H. C. Wang, C. H. Chuang, and H. H. Tsai, "Effect of Annealing Twins on Electromigration in Ag-8Au-3Pd Bonding Wires," Journal of electronic materials, vol. 42, no. 3, pp. 545, 2013.
[34] T. H. Chuang, H. J. Lin, C. H. Chuang, C. H. Tsai, J. D. Lee, and H. H. Tsai, "Durability to Electromigration of an Annealing-Twinned Ag-4Pd Alloy Wire Under Current Stressing," Metallurgical and Materials Transactions A, vol. 45, no. 12, pp. 5574-5583, 2014.
[35] K. C. Chen, W. W. Wu, C. N. Liao, L. J. Chen, and K. Tu, "Observation of Atomic Diffusion at Twin-Modified Grain Boundaries in Copper," Science, vol. 321, no. 5892, pp. 1066-1069, 2008.
[36] S. Wang, L. Gao, M. Li, D. Huang, K. Qian, and H. Chiu, "Electro-Migration of Silver Alloy Wire with Its Application on Bonding," in 2013 14th Electronic Packaging Technology (ICEPT), pp. 789-793, 2013
[37] R. Guo, L. Gao, M. Li, D. Mao, K. Qian, and H. Chiu, "Microstructure Evolution of Ag–8Au–3Pd Alloy Wire during Electromigration," Materials Characterization, vol. 110, pp. 44-51, 2015.
[38] R. Vanselow, R. Masters, and R. Wehnes, "Crystal Forms of Hillocks and Voids Formed by Electromigration on Ultrapure Gold and Silver Wires," Applied Physics A: Materials Science & Processing, vol. 12, no. 4, pp. 341-345, 1977.
[39] H. W. Hsueh, F. Y. Hung, and T. S. Lui, "A Study on Electromigration-Inducing Intergranular Fracture of Fine Silver Alloy Wires," Applied Physics Letters, vol. 110, no. 3, pp. 031902, 2017.
[40] E. Misra, N. Theodore, J. Mayer, and T. Alford, "Failure Mechanisms of Pure Silver, Pure Aluminum and Silver–Aluminum Alloy under High Current Stress," Microelectronics Reliability, vol. 46, no. 12, pp. 2096-2103, 2006.
[41] 王木琴, "工程材料", 台灣復文興業股份有限公司, 1996.
[42] 楊榮顯, "工程材料學", 全華圖書, 2010.
[43] F. Scholz, J. Driver, and E. Woldt, "The Stored Energy of Cold Rolled Ultra High Purity Iron," Scripta materialia, vol. 40, no. 8, pp. 949-954, 1999.
[44] A. Rollett, F. Humphreys, G. S. Rohrer, and M. Hatherly, "Recrystallization and Related Annealing Phenomena," Elsevier, 2004.
[45] L. Blaz, T. Sakai, and J. Jonas, "Effect of Initial Grain Size on Dynamic Recrystallization of Copper," Metal Science, vol. 17, no. 12, pp. 609-616, 1983.
[46] H. Miura, T. Sakai, S. Andiarwanto, and J. Jonas, "Nucleation of Dynamic Recrystallization at Triple Junctions in Polycrystalline Copper," Philosophical Magazine, vol. 85, no. 23, pp. 2653-2669, 2005.
[47] M. R. Drury and F. J. Humphreys, "The Development of Microstructure in Al-5% Mg during High Temperature Deformation," Acta Metallurgica, vol. 34, no. 11, pp. 2259-2271, 1986.
[48] H. Conrad, Z. Guo, and A. Sprecher, "Effect of an Electric Field on The Recovery and Recrystallization of Al and Cu," Scripta metallurgica, vol. 23, no. 6, pp. 821-823, 1989.
[49] Y. Zhou, S. Xiao, and J. Guo, "Recrystallized Microstructure in Cold Worked Brass Produced by Electropulsing Treatment," Materials Letters, vol. 58, no. 12, pp. 1948-1951, 2004.
[50] G. Hu, Y. Zhu, G. Tang, C. Shek, and J. Liu, "Effect of Electropulsing on Recrystallization and Mechanical Properties of Silicon Steel Strips," Journal of Materials Science & Technology, vol. 27, no. 11, pp. 1034-1038, 2011.
[51] F. Ding, G. Tang, Z. Xu, and S. Tian, "A New Method for Improving Strength and Plasticity of Steel Wire," J. Mar. Sci. Technol, vol. 23, p. 160, 2007.
[52] D. Fabrègue, B. Mouawad, and C. R. Hutchinson, "Enhanced Recovery and Recrystallization of Metals due to an Applied Current," Scripta Materialia, vol. 92, pp. 3-6, 2014.
[53] Z. S. Xu and Y. X. Chen, "Effect of Electric Current on the Recrystallization Behavior of Cold Worked α-Ti," Scripta Metallurgica, vol. 22, no. 2, pp. 187-190, 1988.
[54] K. Huang, C. Cayron, and R. E. Logé, "The Surprising Influence of Continuous Alternating Electric Current on Recrystallization Behaviour of a Cold-rolled Aluminium Alloy," Materials Characterization, vol. 129, pp. 121-126, 2017.
[55] 蕭志臻, "通電熱處理效應對7075鋁合金顯微組織及拉伸性質之影響" 碩士學位論文, 國立成功大學材料科學及工程學系, 2008.
[56] K. Mori, S. Maki, and M. Ishiguro, "Improvement of Product Strength and Formability in Stamping of Al–Mg–Si Alloy Sheets Having Bake Hardenability by Resistance Heat and Artificial Aging Treatments," International Journal of Machine Tools and Manufacture, vol. 46, no. 15, pp. 1966-1971, 2006.
[57] S. Maki, M. Ishiguro, K.-I. Mori, and H. Makino, "Thermo-Mechanical Treatment Using Resistance Heating for Production of Fine Grained Heat-Treatable Aluminum Alloy Sheets," Journal of Materials Processing Technology, vol. 177, no. 1–3, pp. 444-447, 2006.
[58] H. Miura, T. Sakai, R. Mogawa, and J. Jonas, "Nucleation of Dynamic Recrystallization and Variant Selection in Copper Bicrystals," Philosophical Magazine, vol. 87, no. 27, pp. 4197-4209, 2007.
[59] H. Shi et al., "Twin Boundary Characters Established during Dynamic Recrystallization in a Nickel Alloy," Materials Characterization, vol. 110, pp. 52-59, 2015.
[60] Y. Jin, B. Lin, M. Bernacki, G. S. Rohrer, A. Rollett, and N. Bozzolo, "Annealing Twin Development during Recrystallization and Grain Growth in Pure Nickel," Materials Science and Engineering: A, vol. 597, pp. 295-303, 2014.
[61] E. Brünger, X. Wang, and G. Gottstein, "Nucleation Mechanisms of Dynamic Recrystallization in Austenitic Steel Alloy 800H," Scripta materialia, vol. 38, no. 12, pp. 1843-1849, 1998.
[62] D. Field, L. Bradford, M. Nowell, and T. Lillo, "The Role of Annealing Twins during Recrystallization of Cu," Acta materialia, vol. 55, no. 12, pp. 4233-4241, 2007.
[63] Y. Wang, W. Z. Shao, L. Zhen, and X. M. Zhang, "Microstructure Evolution during Dynamic Recrystallization of Hot Deformed Superalloy 718," Materials Science and Engineering: A, vol. 486, no. 1, pp. 321-332, 2008.
[64] C. Youngdahl, J. Weertman, R. Hugo, and H. Kung, "Deformation Behavior in Nanocrystalline Copper," Scripta Materialia, vol. 44, no. 8, pp. 1475-1478, 2001.
[65] L. Lu, Y. Shen, X. Chen, L. Qian, and K. Lu, "Ultrahigh Strength and High Electrical Conductivity in Copper," Science, vol. 304, no. 5669, pp. 422, 2004.
[66] L. Lu, X. Chen, X. Huang, and K. Lu, "Revealing the Maximum Strength in Nanotwinned Copper," Science, vol. 323, no. 5914, pp. 607-610, 2009.
[67] M. Dao, L. Lu, Y. F. Shen, and S. Suresh, "Strength, Strain-Rate Sensitivity and Ductility of Copper with Nanoscale Twins," Acta Materialia, vol. 54, no. 20, pp. 5421-5432, 2006.
[68] Y. Shen, L. Lu, Q. Lu, Z. Jin, and K. Lu, "Tensile Properties of Copper with Nano-Scale Twins," Scripta Materialia, vol. 52, no. 10, pp. 989-994, 2005.
[69] R. Abbaschian and R. E. Reed-Hill, "Physical metallurgy principles," Cengage Learning, 2008.
[70] H. J. Shin, H. T. Jeong, and D. N. Lee, "Deformation and Annealing Textures of Silver Wire," Materials Science and Engineering: A, vol. 279, no. 1–2, pp. 244-253, 2000.
[71] V. John, "Introduction to Engineering Materials," Springer, 1983.
[72] D. Hull and D. J. Bacon, "Introduction to Dislocations," Elsevier, 2011.
[73] P. Asoka‐Kumar, K. O’Brien, K. G. Lynn, P. J. Simpson, and K. P. Rodbell, "Detection of Current‐Induced Vacancies in Thin Aluminum–Copper Lines Using Positrons," Applied Physics Letters, vol. 68, no. 3, pp. 406-408, 1996.
[74] P. S. Ho and H. B. Huntington, "Electromigration and Void Observation in Silver," Journal of Physics and Chemistry of Solids, vol. 27, no. 8, pp. 1319-1329, 1966.
[75] H. J. McQueen and C. A. C. Imbert, "Dynamic Recrystallization: Plasticity Enhancing Structural Development," Journal of Alloys and Compounds, vol. 378, no. 1–2, pp. 35-43, 2004.
[76] 張以澄, "黃銅退火雙晶與機械雙晶之顯微組織研究" 碩士學位論文, 國立臺灣大學材料科學及工程學系, 2012.
[77] Y. F. Shen, L. Lu, Q. H. Lu, Z. H. Jin, and K. Lu, "Tensile Properties of Copper with Nano-Scale Twins," Scripta Materialia, vol. 52, no. 10, pp. 989-994, 2005.
[78] H. McQueen and C. Imbert, "Dynamic Recrystallization: Plasticity Enhancing Structural Development," Journal of Alloys and Compounds, vol. 378, no. 1, pp. 35-43, 2004.
[79] L. E. Murr, "Interfacial Phenomena in Metals and Alloys," 1975.
[80] J. H. J. Lothe and J. P. Hirth, "Theory of Dislocations," Wiley, New York, pp. 270, 1982.
[81] Y. Jin, M. Bernacki, G. S. Rohrer, A. D. Rollett, B. Lin, and N. Bozzolo, "Formation of Annealing Twins during Recrystallization and Grain Growth in 304L Austenitic Stainless Steel," in Materials Science Forum, vol. 753, pp. 113-116, 2013
[82] P. R. Rios, F. Siciliano Jr, H. R. Z. Sandim, R. L. Plaut, and A. F. Padilha, "Nucleation and Growth during Recrystallization," Materials Research, vol. 8, pp. 225-238, 2005.
[83] 梁品筑, "銅鋅合金電致再結晶之晶粒細化行為研究" 國立成功大學材料科學及工程學系, 2016.
[84] T. H. Chuang et al., "Thermal Stability of Grain Structure and Material Properties in an Annealing-Twinned Ag–8Au–3Pd Alloy Wire," Scripta Materialia, vol. 67, no. 6, pp. 605-608, 2012.
[85] C. M. Chen, C. C. Huang, C. N. Liao, and K. M. Liou, "Effects of Copper Doping on Microstructural Evolution in Eutectic SnBi Solder Stripes under Annealing and Current Stressing," Journal of Electronic Materials, vol. 36, no. 7, pp. 760-765, 2007.
[86] T. C. Chiu and K. L. Lin, "The Difference in the Types of Intermetallic Compound Formed Between the Cathode and Anode of an Sn–Ag–Cu Solder Joint under Current Stressing," Intermetallics, vol. 17, no. 12, pp. 1105-1114, 2009.
[87] C. M. Chen, Y. M. Hung, C. P. Lin, and W. C. Su, "Effect of Temperature on Microstructural Changes of the Sn–9wt.% Zn Lead-Free Solder Stripe under Current Stressing," Materials Chemistry and Physics, vol. 115, no. 1, pp. 367-370, 2009.
[88] Y. Zhu, S. To, W. B. Lee, X. Liu, Y. Jiang, and G. Tang, "Electropulsing-Induced Phase Transformations in a Zn–Al-based Alloy," Journal of Materials Research, vol. 24, no. 8, pp. 2661-2669, 2011.