本研究利用微衝擊試驗系統探討無鉛銲錫球接點的破壞行為；研究結果顯示，微衝擊測試的特徵曲線可作為界定銲錫球接點機械性質與破壞行為的判斷依據；曲線的半高寬數值可辨別破斷面的種類；破斷能量可用為判斷形成各種破斷面所需要的能量。破壞行為可以分為 Type I（Solder/Solder 的延性破斷面），Type II（Solder/IMC 的界面破斷面），以及 Type III（IMC/Ni 的界面破斷面）；破斷面的半高寬數值以及其對應的能量大小順序是：Type I > Type II > Type III。結合楊式係數、微硬度以及晶格不匹配（Lattice Mismatch）等數值，可以瞭解界面破斷面的形成機制會受到銲錫本身的塑性變形能力以及接點界面處各金屬層之間的 晶格不匹配程度所主導。各種銲錫球接點的延性破斷面（Type I）的比例大小順序如下：SAC101NiIn/AuNi > SAC105/AuNi > SAC205/AuNi > SAC105Co/AuNi > SAC105Ni/AuNi。
迴焊時的反應時間以及冷熱循環測試（TCT），都會影響銲錫球接點的微觀組織以及介金屬化合物的組成與型態，進而提高銲錫球接點界面破斷面（Type II 以及 Type III）的比例。反應時間從 30 秒到 120 秒；界面破斷面的比例由 15.4 % 提昇到 69.2 %。此外，當冷熱循環數增加至 1000 次時，界面破斷面的比例增加至 37.5 %。

This present study investigated the fracture behavior of the Pb-free solder joint with the aid of micro-impact test method. The results of investigation indicated that the characteristic curve of the micro-impact test provides the base for estimating the mechanical properties and identifying the fracture mechanism of the joint. The full width at half maximum (FWHM) can be regarded as the index for defining the fracture type. The fracture energy obtained from the curve gives the estimation of the energy needed for completely detaching the solder joint. The fracture mechanism can be categorized as Type I (fracture at solder/solder), Type II (fracture at Solder/IMC), and Type III (fracture at IMC/Ni). The magnitudes of FWHM and the fracture energy of the corresponding fracture type are in the descending order: Type I > Type II > Type III. Incorporating the values of Young’s modulus, micro hardness, and lattice mismatch, it is understandable that the fracture mechanism is governed by the plastic deformability of the solder alloy and the lattice mismatch between the interfaces. The proportion of the Type I fracture for all the solder joints investigated is in the descending order of SAC101NiIn/AuNi > SAC105/AuNi > SAC205/AuNi > SAC105Co/AuNi > SAC105Ni/AuNi.
The interaction during reflow and the thermal cycle test (TCT) greatly affect the microstructure of the solder joint and the formation of interfacial intermetallic compound. It will further increase the proportion of the interfacial fracture type (Type II and Type III). The proportion of interfacial fracture increases from 15.4 % to 69.2 % when the reaction time increases from 30 sec to 120 sec, while the proportion becomes as high as 37.5 % after 1000 cycles of test.

參考文獻
[1] K. Zeng and K.N. Tu, “Six Cases of Reliability Study of Pb-free Solder Joints in Electronic Packaging Technology”, Materials Science Engineering R, Vol. 38, 2002, p. 55.
[2] M. Li, K.Y. Lee, D.R. Olsen, W.T. Chen, B.T.C. Tan, and S. Mhaisalkar, “Microstructure, Joint Strength and Failure Mechanisms of SnPb and Pb-Free Solders in BGA Packages”, IEEE Transactions on Electronics Packaging, Vol. 25, July 2002, p. 3.
[3] K.N. Tu, and K. Zeng, “Tin-lead（SnPb）Solder Reaction in Flip Chip Technology”, Materials Science and Engineering R, Vol. 34, 2001, p. 1.
[4] C.M. Chuang, P.C. Shin, and K.L Lin, “Mechanical Strength of Sn-3.5Ag-Based Solders and Related Bondings”, Journal of Electronic Materials, Vol. 33, No. 1, 2004, p. 1.
[5] T.T. Mattila and J.K. Kivilahti, “Failure Mechanisms of Lead-Free Chip Scale Package Interconnections under Fast Mechanical Loading”, Journal of Electronic Materials, Vol. 34, No. 7, 2005, p. 969.
[6] J.W. Yoon, S.W. Kim, S.B. Jung, “IMC Morphology, Interfacial Reaction and Joint Reliability of Pb-free Sn-Ag-Cu Solder on Electrolytic Ni BGA Substrate”, Journal of Alloys and Compounds, Vol. 392, 2005, p. 247.
[7] J. Luan, T.Y. Tee, E. Pek, C.T. Lim, and Z. Zhong, “Dynamic Responses and Solder Joint Reliability under Board Level Drop Test”, Microelectronics Reliability, Vol. 47, 2007, p. 450.
[8] F.L. Zhu, H.H. Zhang, R.F. Guan, S. Liu, “Effects of Temperature and Strain Rate on Mechanical Property of Sn96.5Ag3Cu0.5”, Journal of Alloys and Compounds, Vol. 438, 2007, p. 100.
[9] Y.R.D. Chong, F.X. Che, H.L.J. Pang, K. Ng, Y.N.J. Tan, T.H.P. Low, “Drop Impact Reliability Testing for Lead-free and Lead-based Soldered IC Packages”, Microelectronics Reliability, Vol. 46, 2006, p. 1160.
[10] R. Zoran, A.Q. Yasir, M. Pirkka, and R. Jukka, “Reliability Prediction for TFBGA Assemblies”, IEEE Transactions on Components and Packaging Technologies, Vol. 29, No. 2, June 2006, p. 379.
[11] L.P. Zhu and W. Marcinkiewicz, “Drop Impact Reliability Analysis of CSP Packages at Board and Product Levels Through Modeling Approaches”, IEEE Transactions on Components and Packaging Technologies, Vol. 28, No. 3, September 2005, p. 449.
[12] I. Dutta, A. Gopinath, and C. Marshall, “Underfill Constraint Effects during Thermomechanical Cycling of Flip-Chip Solder Joints”, Journal of Electronic Materials, Vol. 31, No. 4, 2002, p. 253.
[13] R. Mayappan, A.B. Ismail, Z.A. Ahmad, T. Ariga, L.B. Hussain, “The Effect of Crosshead Speed on the Joint Strength between Sn-Zn-Bi Lead-free Solders and Cu Substrate”, Journal of Alloys and Compounds, Vol. 436, 2007, p. 112.
[14] H.Y. Lee and J.G Duh, “Influence of Ni Concentration and Ni3Sn4 Nanoparticles on Morphology of Sn-Ag-Ni Solders by Mechanical Alloying”, Journal of Electronic Materials, Vol. 35, 2006, p. 494.
[15] C.W. Hwang, J.G Lee, K. Suganuma and H. Mori, “Interfacial Microstructure between Sn-3Ag-xBi Alloy and Cu Substrate with or without Electrolytic Ni Plating, Journal of Electronic Materials, Vol. 32, 2003, p. 52.
[16] I.E. Anderson, B.A. Cook, J. Harringa and R.L. Terpstra, “Microstructural Modifications and Properties of Sn-Ag-Cu Solder Joints Induced by Alloying”, Journal of Electronic Materials, Vol. 31, 2002, p. 1166.
[17] S.Q. Ou, Y.H. Xu, K.N. Tu, M.O. Alam and Y.C. Chan, “A Study of Impact Reliability of Lead-free BGA Balls on Au/Electronic Ni/Cu Bond Pad”, Materials, Technology and Reliability of Advanced interconnects, Vol. 863, 2005, p. 381.
[18] C.M.T. Law, C.M.L. Wu, D.Q. Yu, L. Wang, J.K.L. Lai, “Microstructure, Solderability, and Growth of Intermetallic Compounds of Sn-Ag-Cu-RE Lead-free Solder Alloys”, Journal of Electronic Materials, Vol. 35, 2006, p. 89.
[19] W.M. Xiao, Y.W. Shi, G.C. Xu, R. Ren, F. Guo, Z.D. Xia, Y.P. Lei, “Effect of Rare Earth on Mechanical Creep-fatigue Property of SnAgCu Solder Joint”, Journal of Alloys and Compounds, Vol. 472, 2009, p. 198.
[20] S.T. Jenq, H.H. Chang, Y.S. Lai, and T.Y. Tsai, “High Strain Rate Compression Behavior for Sn-37Pb Eutectic Alloy, Lead-free Sn-1Ag-0.5Cu and Sn-3Ag-0.5Cu Alloys”, Microelectronics Reliability, Vol. 49, 310 (2009).
[21] I.E. Anderson, B.A. Cook, J.L. Harringa, and R.L. Terpstra, “Sn-Ag-Cu Solders and Solder Joints: Alloy Development, Microstructure, and Properties”, JOM: the Journal of the Minerals, Metals & Materials Society, June 2002 pp. 26.
[22] J.W. Yoon, H.S. Chun, and S.B. Jung, “Investigation of Interfacial Reaction and Joint Reliability between Eutectic Sn-3.5Ag Solder and ENIG-Plated Cu Substrate during High Temperature Storage Test”, Journal of Materials Science - Materials in Electronics, Vol. 18, 2007, p. 559.
[23] L.H. Xu, John H.L. Pang, and F.X. Che, Impact of Thermal Cycling on Sn-Ag-Cu Solder Joints and Board-Level Drop Reliability”, Journal of Electronic Materials, Vol. 37, No. 6, 2008, p. 880.
[24] S.S. Ha, J.K. Jang, S.O. Ha, J.W. Kim, J.W. Yoon, B.W. Kim, S.K. Park, and S.B. Jung, “Mechanical Property Evaluation of Sn-3.0A-0.5Cu BGA Solder Joints Using High-Speed Ball Shear Test”, Journal of Electronic Materials, Vol. 38, No. 12, 2009, p. 2489.
[25] S. Terashima, Y. Kariya, T. Hosoi, and M. Tanaka, “Effect of Silver Content on Thermal Fatigue Life of Sn-xAg-0.5Cu Flip-chip Interconnects”, Journal of Electronic Materials, Vol. 32, 2003, p. 1527.
[26] M. Date, T. Shoji, M. Fujiyoshi, K. Sato, and K.N. Tu, “Impact Reliability of Solder Joints”, in Proceedings of 54th IEEE Electronic Components and Technology Conference , Las Vegas, NV, 2004, p. 668.
[27] W.H. Zhu, L.H. Xu, John H.L. Pang, X.R. Zhang, Edith Poh, Y.F. Sun, Anthony Y.S. Sun, C.K. Wang, H.B. Tan, “Drop Reliability Study of PBGA Assemblies with SAC305, SAC105 and SAC105-Ni Solder Ball on Cu-OSP and ENIG Surface Finish”, in Proceedings of 58th IEEE Electronic Components and Technology Conference, Orlando, Florida, 2008, p. 1667.
[28] D. Suh, D. W. Kim, P. Liu, H. Kim, J. A. Weninger, C.M. Kumer, A. Prasad, B.W. Grimsley, and H.B. Tejada, “Effects of Ag Content on Fracture Resistance of Sn-Ag-Cu Lead-free Solders under High-strain Rate Condition”, Materials Science and Engineering A, Vol. 460-461, 2007, p. 595.
[29] S.C. Cheng and K.L. Lin, “The Thermal Property of Lead-Free Sn-8.55Zn-1Ag-XAl Solder Alloys and its Wetting Interaction with Cu, Journal of Electronic Materials, Vol. 31, 2002, p. 940.
[30] K.L. Lin and C.L. Shih, “Microstructure and Thermal Behavior of Sn-Zn-Ag Solders”, Journal of Electronic Materials, Vol. 32, 2003, p. 1496.
[31] Y.W. Wang, Y.W. Lin, C.T. Tu, and C.R. Kao, “Effect of Minor Fe, Co, and Ni Additions on the Reaction between SnAgCu Solder and Cu”, Journal of Alloys and Compounds, Vol. 478, 2009, p. 121.
[32] F. Gao, T. Takemoto, and H. Nishikawa, “Effects of Co and Ni Addition on Reactive Diffusion between Sn-3.5Ag Solder and Cu during Soldering and Annealing”, Materials Science and Engineering A, Vol. 420, 2007, p. 39.
[33] D.H. Kim, M.G. Cho, S.K. Seo, and H.M. Lee, “Effects of Co Addition on Bulk Properties of Sn-3.5Ag Solder and Interfacial Reactions with Ni-P UBM”, Journal of Electronic Materials, Vol. 38, 2009, p. 39.
[34] Y.H. Lee and H.T. Lee, “Shear Strength and Interfacial Microstructure of Sn-Ag-xNi/Cu Single Shear Lap Solder Joints”, Materials Science and Engineering A, Vol. 444, 2007, p. 75.
[35] Y. Kariya and M. Otsuka, “Mechanical Fatigue Characteristics of Sn-3.5Ag-X (X=Bi, Cu, Zn and In) Solder Alloys”, Journal of Electronic Materials, Vol. 27, 1998, p. 1229.
[36] S.Q. Ou, Y.H. Xu, and K.N. Tu, “Micro-impact Test on Lead-free BGA Balls on Au/Electrolytic Ni/Cu Bond Pad”, in Proceedings of 55th IEEE Electronic Components and Technology Conference, Orlando, Florida, 2005, p.467.
[37] N.S. Liu and K.L. Lin, “The Effect of Ga Content on the Wetting Reaction and Interfacial Morphology Formed between Sn-8.5Zn-0.5Ag-0.1Al-xGa Solders and Cu”, Scripta Materialia, Vol. 54, 2006, p. 219.
[38] T.H. Chuang, S.F. Yen, and M.D. Cheng, “Intermetallic Reactions in Sn3Ag0.5Cu and Sn3Ag0.5Cu0.06Ni0.01Ge Solder BGA Package with Au/Ni Surface Finishes”, Journal of Electronic Materials, Vol. 35, 2006, p. 302.
[39] T.S. Wang, S.C. Liu, Y.L. Huang, K.L. Lin, and Y.S. Lai, “The Microstructure and Fracture Behavior of Sn-3Ag-0.5Cu Solder Joints”, Proceedings - The 3rd IMPACT/The 10th EMPS Joint Conference 2008, Taipei, Taiwan, October 22-24, 2008, p. 645.
[40] E.H. Wong, S.K.W. Seah, and V.P.W. Shim, “A Review of Board Level Solder Joints for Mobile Applications”, Microelectronics Reliability, Vol. 48, 2008, p. 1747.
[41] C.E. Ho, S.C. Yang and C.R. Kao, “Interfacial Reaction Issues for Leaf-free Eutectic Solders”, Journal of Materials Science - Materials in Electronics, Vol. 18, 2007, p. 155.
[42] Y.S. Lai, C.R. Kao, and H.C. Chang, and C.L. Kao, “Effect of Multiple Reflow Cycles on Ball Impact Responses of Sn-Ag-Cu Solder Joints”, Soldering & Surface Mount Technology Vol. 21, No. 3, 2009, p. 4.
[43] E.H. Wong, R. Rajoo, S.K.W. Seah, C.S. Selvanayagam, W.D. Driel, J.F.J.M. Caers, X.J. Zhao, N. Owens, L.C. Tan, M. Leoni, P.L. Eu, Y.S. Lai, and C.L. Yeh, “Correlation Studies for Component Level Ball Impact Shear Test and Board Level Drop Test”, Microelectronic Reliability, Vol. 48, 2008, p. 1069.
[44] K.S. Lin, H.Y. Huang, and C.P. Chou, “Interfacial Reactions and Bonding Strength of Sn-xAg-0.5Cu/Ni BGA Solder Joints”, Journal of Materials Engineering and Performance, Vol. 18, No. 2, 2009, p. 182.
[45] J.W. Kim, S.B. Jung, “Reexamination of the Solder Ball Shear Test for Evaluation of the Mechanical Joint Strength”, International Journal of Solids and Structures, Vol. 43, 2006, p. 1928.
[46] T. You, Y. Kim, J. Kim, and J. Lee, B. Jung, J. Moon, and H. Choe, “Predicting the Drop Performance of Solder Joints by Evaluating the Elastic Strain Energy from High-Speed Ball Pull Tests”, Journal of Electronic Materials, Vol. 38, No. 3, 2009, p. 410.
[47] JESD22-B117, Solder Ball Shear, JEDEC Solid State Technology Association, 2000.
[48] J.J. Sundelin, S.T. Nurmi, T.K. Lepisto and E.O. Ristolainen, “Mechanical and Microstructural Properties of SnAgCu Solder Joints”, Materials Science and Engineering A, Vol. 420, 2006, p. 55.
[49] Y.C. Liu, W.H. Lin, H.J. Lin and T.H. Chuang, “Intermetallic Reactions in Sn-8Zn-20In Solder Ball Grid Array Packages with Au/Ni/Cu and Ag/Cu Pads”, Journal of Electronic Materials, Vol. 35, 2006, p. 147.
[50] C.Q. Liu, P. Conway, D.Z. Li and M. Hendriksen, “Analysis of the Micro-mechanical Properties in Aged Lead-free, Fine Pitch Flip Chip Joints”, Journal of Electronic Packaging, Vol. 126, 2004, p. 359.
[51] J.W. Yoon, S.W. Kim and S.B. Jung, “Interfacial Reaction and Mechanical Properties of Eutectic Sn-0.7Cu/Ni BGA Solder Joints during Isothermal Long-term Aging”, Journal of Alloys and Compounds, Vol. 391, 2005, p. 82.
[52] J.Y.H. Chia, B. Cotterell, T.C. Chai, “The Mechanics of the Solder Ball Shear Test and the Effect of Shear Rate”, Materials Science and Engineering A, Vol. 417, 2006, p. 259.
[53] C.L. Yeh and Y.S. Lai, “Transient Fracturing of Solder Joints Subjected to Displacement-controlled Impact Loads, Microelectronics Reliability, Vol. 46, 2006, p. 885.
[54] T.Y. Tsai, C.L. Yeh, Y.S. Lai, and R.S. Chen, “Transient Submodeling Analysis for Board-level Drop Tests of Electronic Packages”, Electronics Packaging Manufacturing, IEEE Transaction, Vol. 30, 2007, p. 54.
[55] JESD22-B117A, Solder Ball Shear, JEDEC Solid State Technology Association, October 2006.
[56] S.K.W. Seah, C.T. Lim, E.H. Wong, V.B.C. Tan, V.P.W. Shim, “Mechanical Response of PCBs in Portable Electronic Products During Drop Impact”, 4th Electronics Packaging Technology Conference, 2002, p.120.
[57] K.T. Tsai, F.L. Liu, E.H. Wong, and R. Rajoo, “High Strain Rate Testing of Solder Interconnections”, Soldering & Surface Mount Technology, Vol. 18, 2006, p. 12.
[58] J.A. Zukas, T. Nicholas, H.F. Swift, L.B. Greszczuk, and D.R. Curran, “Impact Dynamics”, John Wiley & Sons, Inc., New York, pp.9-10, pp.15-17, 1982.
[59] D.S. Liu, C.Y. Kuo, C.L. Hsu, Geng-Shin Shen, Yu-Ren Chen, Kuo-Cheng Lo, “Failure Mode Analysis of Lead-free Solder Joints under High Speed Impact Testing”, Materials Science and Engineering A, Vol. 494, 2008, p. 196.
[60] JESD22-A104C, Temperature Cycling (TCT), JEDEC Solid State Technology Association, May 2005.
[61] JESD22-A103C, High Temperature Storage Life (HTST), JEDEC Solid State Technology Association, November 2004.
[62] JESD22-A106A, Thermal Shock (TST), Electronic Industries Association, April 1995.
[63] JESD22-A110B, Highly-Accelerated Temperature and Humidity Stress Test (HAST), JEDEC Solid State Technology Association, February 1999.
[64] JEDEC J-STD-020D, Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount Devices, IPC/JEDEC Solid State Technology Association, June 2007.
[65] M.A. Meyers, Dynamic Behavior of Material, (John Willey, 1994)
[66] I. Ohnuma, M. Miyashita, K. Anzai, X.J. Liu, H. Ohtani, R. Kainuma, and K. Ishida, “Phase Equilibria and the Related Properties of Sn-Ag-Cu Based Pb-free Solder Alloys”, Journal of Electronic Materials, Vol. 29, 2000, p.1137.
[67] D. Suh, D.W. Kim, P. Liu, H. Kim, J.A. Weninger, C.M. Kumer, A. Prasad, B.W. Grimsley, and H.B. Tejada, “Effects of Ag Content on Fracture Resistance of Sn-Ag-Cu Lead-free Solders under High-strain Rate Conditions”, Materials Science and Engineering A, Vol. 460-461, 2007, p. 595.
[68] J.W. Kim, and S.B. Jung, “Experimental and Finite Element Analysis of the Shear Speed Effects on the Sn-Ag and Sn-Ag-Cu BGA Solder Joints”, Materials Science and Engineering A, Vol. 371, 2004, p. 267.
[69] L. Xu and H.L. Pang, “Nanoindentation on SnAgCu Lead-free Solder Joints and Analysis”, Journal of Electronic Materials, Vol. 35, No. 12, 2006, p. 2107.
[70] G.Y. Jang, J.W. Lee, and J.G. Duh, “The Nanoindentation Characteristics of Cu6Sn5, Cu3Sn, and Ni3Sn4 Intermetallic Compounds in the Solder Bump”, Journal of Electronic Materials, Vol. 33, No. 10, 2004, p. 1103.
[71] G. Ghosh, ”Elastic Properties, Hardness, and Indentation Fracture Toughness of Intermetallics Relevant to Electronic Packaging”, Journal of Materials Research, Vol. 19, No. 5, 2004, p. 1439.
[72] L. Xu, and J.H.L. Pang, “Nano-indentation Characterization of Ni-Cu-Sn IMC Layer Subject to Isothermal Aging”, Thin Solid Films, Vol. 504, 2006, p. 362.
[73] A.M. Minor and J.W. Morris, “Inhibiting Growth of the Au0.5Ni0.5Sn4 Intermetallic Layer in Pb-Sn Solder Joints Reflowed in Au/Ni Metallization”, Journal of Electronic Materials, Vol. 29, 2000, p.1170.
[74] C.E. Ho, R. Zheng, G.L. Luo, A.H. Lin, and C.R. Kao, “Formation and Resettlement of (AuxNi1-x)Sn4 in Solder Joints of Ball-Grid-Array Packages with the Au/Ni Surface Finish”, Journal of Electronic Materials, Vol. 29, 2000, p.1175.
[75] T.C. Hsuan and K.L. Lin, “Microstructure Evolution of -AgZn3 and -Zn Phase in Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga Solder during Aging Treatment”, Journal of Alloys and Compounds, Vol. 469, 2009, p.350.
[76] L.J. Tai, I. Tsai, and E. Wu, “Mechanical Properties of Ni3Sn4 and Cu3Sn Determined by Inverse Method”, IEEE Transactions on Components and Packaging Technologies, Vol. 31, 2008, p. 503.
[77] M.Y. Tsai, C.H. Hsu, and C.T. Wang, “Investigation of Thermomechanical Behaviors of Flip Chip BGA Packages during Manufacturing Process and Thermal Cycling”, IEEE Transactions on Components and Packaging Technologies, Vol. 27, 2004, p. 568.
[78] O. Nousiainen, L. Lehtiniemi, T. Kangasvieri, R. Rautioaho, and J. Vahakangas, “Thermal Fatigue Endurance of Collapsible 95.5Sn4Ag0.5Cu Spheres in LTCC/PWB Assemblies”, Microelectronics Reliability, Vol. 48, 2008, p. 622.
[79] M.Y. Tsai, H.Y. Chang, and M. Pecht, “Warpage Analysis of Flip-Chip PBGA Packages Subject to Thermal Loading”, IEEE Transactions on Device and Materials Reliability, Vol. 9, 2009, p. 419.
[80] Y.F. Duann, J.H. Chiang, S.J. Yang, and H.W. Chang, “Scanning Electron Microscopy Study of the Cross Section of Intermetallic Compound in the Solder Ball on the Plastic Ball Grid Array Package Following Reliability Tests”, Journal of Electronic Materials, Vol. 34, 2005, p. 1026.
[81] H.W. Chiang, K. Chang, and J.Y. Chen, “The Effect of Ag Content on the Formation of Ag3Sn Plates in Sn-Ag-Cu Lead-Free Solder”, Journal of Electronic Materials, Vol. 35, 2006, p. 2074.