本研究嘗試探討無鉛銲錫之錫銀銅及錫鋅銀鋁鎵銲錫合金與底層銅金屬在焊錫接合過程，初期固液界面反應以及界面反應物的凝核機制。
錫銀銅合金與銅金屬經過250℃持溫15秒焊錫接合過程後，銲錫與底層銅金屬在界面生成的介金屬化合物，從銅金屬到銲錫依序為Cu3Sn與Cu6Sn5；而錫鋅銀鋁鎵銲錫合金與銅金屬在界面生成之介金屬化合物為Cu5Zn8。銅金屬與錫銀銅銲錫合金在15秒迴焊過程中，在緊鄰銅金屬表面約50奈米的區域形成非晶質Cu-Sn擴散區，且該擴散區內有Cu3Sn奈米晶胞分佈；錫鋅銀鋁鎵銲錫合金與銅金屬界面，存在著非晶態之雙層結構，包括約5奈米純銅的區域及非晶質Cu-Zn擴散區，在Cu-Zn擴散區可觀察到Cu5Zn8奈米晶胞分佈。歸納本研究之實驗結果顯示，界面介金屬化合物凝核是經由均質凝核機制，本研究提擬錫鋅銀鋁鎵銲錫金屬界面反應至凝核階段之機制，藉以說明迴焊界面凝核之行為。此機制敘述介金屬化合物組成元素相互擴散形成擴散層，介金屬化合物則在此非晶擴散層，經由均質成核機制生成。

The aim of this research is to investigate the interfacial reaction of Sn-Ag-Cu/Sn–Zn–Ag-Al-Ga solders with Cu substrate during the early stage of soldering. The nucleation behavior of the interfacial intermetallic compound formed between solders and Cu substrate was investigated as well.
The intermetallic compounds formed between the SnAgCu solder and the Cu substrate are Cu3Sn and Cu6Sn5, sequentially from Cu substrate to solder, during soldering at 250℃ for 15 seconds. Cu5Zn8 is the interfacial compound that formed at the interface between Sn–Zn–Ag-Al-Ga solder and Cu substrate after reflow. An amorphous layer with a thickness of 50 nm exists immediately next to the Cu substrate. Nanocrystalline ε-Cu3Sn cells dispersed within the amorphous Cu-Sn diffusion region. For soldering with the Sn-ZnAg-Al-Ga solder, an amorphous double layer was formed at the substrate surface, which consists of a 5nm pure Cu region and a Cu-Zn diffusion region. Nanocrystalline intermetallic compound (IMC) Cu5Zn8 was observed in the Cu-Zn diffusion region. The experimental results of this study indicated that the formation of interfacial IMC takes place through homogeneous nucleation. The mechanism of the interfacial interaction from dissolution to nucleation of the interfacial IMC was proposed for the Sn-ZnAg-Al-Ga solder to illustrate the interfacial nucleation behavior of the soldering process. The mechanism describes the counter diffusion of the constituent elements of the IMC. The IMC formed through homogeneous nucleation within the amorphous diffusion zone.

參考文獻
1. M. Abtew and G. Selvaduray, 「Lead-free Solders in Microelectronics」, Materials Science and Engineering R., Vol. 27, pp. 95~141, 2000.
2. A. Z. Miric and A. Girusd, 「Lead-Free Alloys」, Soldering and Surface Mount Technology, Vol. 10, pp. 19~25, 1998.
3. K. Zeng and K. N. Tu, 「Six Cases of Reliability Study of Pb-Free Solder Joints in Electronic Packaging Technology」, Materials Science and Engineering R, Vol. 38, pp. 55~105, 2002.
4. Y. Li, K. S. Moon and C. P. Wong, 「Electronic Without Lead」, Science, Vol. 308, pp. 1419~1420, 2005.
5. M. R. Marks, 「Effect of Burn-in on Shear Strength of 63Sn-37Pb Solder Joints on an Au/Ni/Cu Substrate」, Journal of Electronic Materials, Vol. 31, pp. 265~271, 2002.
6. J. G. Lee and K. N. Subramanian, 「Effect of Dwell Times on Thermomechanical Fatigue Behavior of Sn-Ag-Based Solder Joints」, Journal of Electronic Materials, Vol. 32, pp. 523~530, 2003.
7. S. H. Kim, J. Y. Kim, J. Yu and T. Y. Lee, 「Residual Stress and Interfacial Reaction of the Electroplated Ni-Cu Alloy Under Bump Metallurgy in the Flip-Chip Solder Joint」, Journal of Electronic Materials, Vol. 33, pp. 948~957, 2004.
8. H. K. Kim, K. N. Tu and P. A. Totta, 「Ripening-Assisted Asymmetric Spalling of Cu-Sn Compound Spheroids in Solid Joints on Si Wafers」, Applied Physics Letters, Vol. 68, pp. 2204~2206, 1996.
9. M. Li, F. Zhang, W.T. Chen, K. Zeng, K. N. Tu, H. Balkan and P. Elenius, 「Interfacial Microstructure Evolution between Eutectic SnAgCu Solder and Al/Ni(V)/Cu Thin Films」, Journal of Materials Research, Vol. 17, pp. 1612~1621, 2002.
10.H. K. Kim, H. K. Liou and K. N. Tu, 「Three-Dimensional Morphology of a very Rough Interface Formed in the Soldering Reaction between Eutectic SnPb and Cu」, Applied Physics Letters, Vol. 66, pp. 2337~2339, 1995.11.H. K. Kim and K. N. Tu, 「Rate of Consumption of Cu in Soldering Accompanied by Ripening」, Applied Physics Letters, Vol. 67, pp. 2002~2004, 1995.
12.H. K. Kim and K. N. Tu, 「Kinetic Analysis of the Soldering Reaction between Eutectic SnPb Alloy and Cu Accompanied by Ripening」, Physical Review B, Vol. 53, pp. 16027~16034, 1996.
13.M. Schaefer, R. A. Fournelle and J. Liang, 「Theory for Intermetallic Phase Growth between Cu and Liquid Sn-Pb Solder Based on Grain Boundary Diffusion Control」, Journal of Electronic Materials, Vol. 27, pp. 1167~1176, 1998.
14.A. M. Guask and K. N. Tu, 「Kinetic Theory of Flux-Driven Ripening」, Physical Review B, Vol. 66, pp. 115403-1~115403-14, 2002.
15.D. Ma, W. D. Wang and S. K. Lahiri, 「Scallop Formation and Dissolution of Cu-Sn Intermetallic Compound during Solder Reflow」, Journal of Applied Physics, Vol. 91, pp. 3312~3317, 2002.
16.J. Gorlich, G. Schmitz and K. N. Tu, 「On the Mechanism of the Binary Cu/Sn Solder Reaction」, Applied Physics Letters, Vol. 86, pp. 053106~053109, 2005.
17.C. H. Yu and K. L. Lin, 「The Atomic-Scale Studies of the Behavior of Crystal Dissolution in a Molten Metal」, Chemical Physics Letters, Vol. 418, pp. 433~436, 2006.
18.S. W. Yoon, J. R. Soh, H. M. Lee and B. J. Lee, 「Thermodynamics-Aided Alloy Design and Evaluation of Pb-Free Solder, Sn-Bi-In-Zn System」, Acta Materialia, Vol. 45, pp. 951~960, 1997.
19.K. Suganuma, K. Niihara, T. Shoutoku and Y. Nakamura, 「Wetting and Interface Microstructure between Sn-Zn Binary Alloys and Cu」, Journal of Materials Research, Vol. 13, pp. 2859~2865, 1998.
20.C. H. Yu and K. L. Lin, 「Early Stage Soldering Reaction and Interfacial Microstructure Formed between Molten Sn-Zn-Ag on Cu Substrate」, Journal of Materials Research, Vol. 20, pp. 1242~1249, 2005.
21.C. H. Yu and K. L. Lin, 「Early Dissolution Behavior of Copper in a Molten Sn-Zn-Ag Solder」, Journal of Materials Research, Vol. 20, pp. 666~671, 2005.
22.S. Bader, W. Gust and H. Hieber, 「Rapid Formation of Intermetallic Compounds Interdiffusion in the Cu-Sn and Ni-Sn systems」, Acta Metallurgica et Materialia, Vol. 43, pp. 329~337, 1995.
23.D. Gur and M. Bamberger, 「Reactive Isothermal Solidification in the Ni-Sn System」, Acta Materialia, Vol. 46, pp. 4917~4923, 1998.
24.W. K. Choi and H. M. Lee, 「Prediction of Primary Intermetallic Compound Formation during Interfacial Reaction between Sn-Based Solder and Ni Substrate」, Scripta Materialia, Vol. 46, pp. 777~781, 2002.
25.Y. W. Lin and K. L. Lin, 「The Early Stage Dissolution of Ni and the Nucleation of Ni-Sn Intermetallic Compound at the Interface during the Soldering of Sn-3.5Ag on a Ni Substrate」, Journal of Applied Physics, Vol. 108, pp. 063536-1~063536-4, 2010.
26.J. W. Jang, P. G. Kim, K. N. Tu, D. R. Frear and P. Thompson, 「Solder Reaction-Assisted Crystallization of Electroless Ni-P under Bump Metallization in Low Cost Flip Chip Technology」, Journal of Applied Physics, Vol. 85, pp. 8456~8463, 1999.
27.H. Matsuki, H. Ibuka and H. Saka, 「TEM Observation of Interfaces in a Solder Joint in a Semiconductor Device」, Science and Technology of Advanced Materials, Vol. 3, pp. 261~270, 2002.
28.C. W. Hwang, K. Suganuma, M. Kiso and S. Hashimoto, 「Interface Microstructures between Ni-P Alloy Plating and Sn-Ag-(Cu) Lead-Free Solders」, Journal of Materials Research, Vol. 18, pp. 2540~2543, 2003.
29.C. C. Pan, C. H. Yu and K. L. Lin, 「The Amorphous Origin and the Nucleation of Intermetallic Compound at the Interface during the Soldering of Sn-3.5Ag-0.5Cu on a Cu Substrate」, Applied Physics Letters, Vol. 93, pp. 061912-1~061912-3, 2008.
30.J. O. Suh, K. N. Tu and N. Tamura, 「Dramatic Morphological Change of Scallop-Type Cu6Sn5 Formed on (001) Single Crystal Copper in Reactions between Molten SnPb Solder and Cu」, Applied Physics Letters, Vol. 91, pp. 051907-1~057907-3, 2007.
31.J. O. Suh, K. N. Tu and N. Tamura, 「Preferred Orientation Relationship between Cu6Sn5 Scallop-Type Grains and Cu Substrate in Reactions between Molten Sn-Based Solders and Cu」, Journal of Applied Physics, Vol. 102, pp. 063511-1~063511-7, 2007.
32.P. J. Shang, Z. Q. Liu, X. Y. Pang, D. X. Li and J. K. Shang, 「Growth Mechanism of Cu3Sn on the Polycrystalline and Single Crystalline Cu Substrate」, Acta Materialia, Vol. 57, pp. 4697~4706, 2009.
33.P. J. Shang, Z. Q. Liu, D. X. Li and J. K. Shang, 「Directional Growth of Cu3Sn at the Reactive Interface between SnBi Solder and (100) Single Crystal Cu」, Scripta Materialia, Vol. 59, pp. 317~320, 2008.
34.K. K. Wang, D. Gan and K. C. Hsieh, 「Orientation Relationship, Interface, and Microstructure ofη-Cu6Sn5 Formed in the Early-Stage Reaction between Cu and Molten Sn」, Thin Solid Films, Vol.519, pp. 1380~1386, 2010.
35.K. K. Wang, D. Gan, K. C. Hsieh and S. Y. Chiou, 「The Microstructure of η-Cu6Sn5 and its Orientation Relationship with Cu in the Early Stage of Growth」, Thin Solid Films, Vol.518, pp. 1667~1674, 2010.
36.K. J. Wang, Y. C. Lin, J. G. Duh, C. Y. Cheng and J. J. Lee, 「In Situ Investigation of the Interfacial Reaction in Sn/Cu System by Synchrotron Radiation」, Journal of Materials Research, Vol. 25, pp. 972~975, 2010.
37.K. N. Tu, A. M. Gusak and M. Li, 「Physics and Materials Challenges for Lead-Free Solders」, Journal of Applied Physics, Vol. 93, pp. 1335~1353, 2003.
38.C. E. Ho, S. C. Yang and C. R. Kao, 「Interfacial Reaction Issues for Lead-Free Electronic Solders」, Journal of Materials Science: Materials in Electronics, Vol.18, pp. 155~174, 2007.
39.M. S. Park and R. Arroyave, 「Formation and Growth of Intermetallic Compound Cu6Sn5 at Early Stages in Lead-Free Soldering」, Journal of Electronic Materials, Vol. 39, pp. 2574-2582, 2010.
40.C. K. Chung, J. G. Duh and C. R. Kao, 「Direct Evidence for a Cu-Enriched Region at the Boundary between Cu6Sn5 and Cu3Sn during Cu/Sn Reaction」, Scripta Materialia, Vol. 63, pp. 258~260, 2010.
41.M. S. Park and R. Arroyave, 「Early Stages of Intermetallic Compound Formation and Growth during Lead-Free Soldering」, Acta Materialia, Vol. 58, pp. 4900~4910, 2010.
42.J. Gong, C. Liu, P. P. Conway and V. V. Silberschmidt, 「Initial Formation of CuSn Intermetallic Compounds between Molten SnAgCu Solder and Cu Substrate」, Scripta Materialia, Vol. 60, pp. 333~335, 2009.
43.J. Y. Park, C. U. Kim, T. Carper, and V. Puligandla, 「Phase Equilibria Studies of Sn-Ag-Cu Eutectic Solder Using Differential Cooling of Sn-3.8Ag-0.7Cu Alloys」, Journal of Electronic Materials, Vol. 32, pp. 1297-1302, 2003.
44.N. S. Liu and K. L. Lin, 「The Effect of Ga Content on the Wetting Reaction and Interfacial Morphology Formed between Sn-8.55Zn-0.5Ag-0.1Al-xGa Solders and Cu」, Scripta Materialia, Vol. 54, pp. 219~224, 2006.
45.S. K. Kang, W. K. Choi, D. Y. Shih, D. W. Henderson, T. Gosselin, A Sarkhel, C.Goldsmith and K. J. Puttlitz, 「Ag3Sn Plate Formation in the Solidification of Near-Ternary Eutectic Sn-Ag-Cu」, JOM, Vol 55, pp. 61~65, 2003.
46.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, pp. 52~62, 2003.
47.W. Peng, E. Monlevade and M. E. Marques, 「Effect of Thermal Aging on the Interfacial Structure of SnAgCu Solder Joints on Cu」, Microelectronics Reliability, Vol. 47, pp. 2161~2168, 2007.
48.T. Laurila, V. Vuorinen and J. K. Kivilahti, 「Interfacial Reactions between Lead-Free Solders and Common Base Materials」, Materials Science and Engineering R, Vol. 49, pp. 1~60, 2005.
49.T. B. Massalski, Binary Alloy Phase Diagrams, ASM International, Materials Park, Ohio, Vol. 1, 1986, p. 965.
50.B. J. Lee, N. M. Hwang and H. M. Lee, 「Prediction of Interface Reaction Products between Cu and various Solder Alloys by Thermodynamic Calculation」, Acta Materialia, Vol. 45, pp. 1867~1874, 1997.
51.R. A. Gagliano, G. Ghosh and M. E. Fine, 「Nucleation Kinetics of Cu6Sn5 by Reaction of Molten Tin with a Copper Substrate」, Journal of Electronic Materials, Vol. 31, pp. 1195~1202, 2002.
52.P. T. Vianco, P. F. Hlava and A. C. Kilgo, 「Intermetallic Compound Layer Formation between Copper and Hot-Dipped 100In, 50In-50Sn, 100Sn, and 63Sn-37Pb Coatings」, Journal of Electronic Materials, Vol. 23, pp. 583~594, 1994.
53.T. H. Chuang, H. M. Wu, M. D. Cheng, S. Y. Chang and S. F. Yen, 「Mechanisms for Interfacial Reactions between Liquid Sn-3.5Ag Solders and Cu Substrate」, Journal of Electronic Materials, Vol. 33, pp. 22~27, 2004.
54.C. W. Hwang, K. S. kim and K. Suganuma, 「Interfaces in Lead-Free Soldering」, Journal of Electronic Materials, Vol. 32, pp. 1249~1256, 2003.
55.V. Vuorinen, T. Laurila, T. Mattila, E. Heikinheimo and J. K. Kivilahti, 「Solid-State Reactions between Cu(Ni) Alloys and Sn」, Journal of Electronic Materials, Vol. 36, pp. 1355~1362, 2007.
56.T. B. Massalski, Binary Alloy Phase Diagrams, ASM International, Materials Park, Ohio, Vol. 1, 1986, p. 981.
57.C. M. Chuang, H. T. Hung, P. C. Liu and K. L. Lin, 「The Interfacial Reaction between Sn-Zn-Ag-Al-Ga Solders and Metallized Cu Substrates」, Journal of Electronic Materials, Vol. 33, pp. 7~13, 2004.
58.N. S. Liu and K. L. Lin, 「The Effect of Ga Content on the Wetting Reaction and Interfacial Morphology Formed between Sn-8.55Zn-0.5Ag-0.1Al-xGa Solders and Cu」, Scripta Materialia, Vol. 54, pp. 219~224, 2006.
59.R. S. Lai, K. L. Lin and B. Salam, 「Suppressing Growth of the Cu5Zn8 Intermetallic Layer in Sn-Zn-Ag-Al-Ga/Cu Solder Joints」, Journal of Electronic Materials, Vol. 38, pp. 88~92, 2009.
60.M. C. Wang, S. P. Yu, T. C. Chang and M. H. Hon, Formation and Morphology of the Intermetallic Compounds Formed at the 91Sn-8.55Zn-0.45Al Lead-Free Solders Alloy/Cu Interface」, Journal of Alloy Compounds, Vol. 389, pp. 133~139, 2005.
61.R. Hultgren, P.D. Desai, D.T. Hawkins, M. Gleiser, K.K. Kelley, Selected Values of the Thermodynamic Properties of Binary Alloy, ASM, Metals Park, Ohio, 1973, p 118.
62.R. Hultgren, P.D. Desai, D.T. Hawkins, M. Gleiser, K.K. Kelley, Selected Values of the Thermodynamic Properties of Binary Alloy, ASM, Metals Park, Ohio, 1973, p. 816.
63.B. F. Duson, 「Diffusion of Gold and Silver in Tin Single Crystals」,Journal of Applied Physics, Vol. 37, pp. 2375~2377, 1966. 64.F. H. Huang and H. B. Huntington, 「Diffusion of Sb124,
Cd109, Sn113, and Zn65 in Tin」, Physical Review B, Vol. 9, pp. 1479~148, 1974.
65.S. C. Cheng and K. L. Lin, 「Interfacial Evolution between Cu and Pb-Free Sn-Zn-Ag-Al Solders upon Aging at 150℃」, Journal of Materials Research, Vol. 18, pp. 1795~1803, 2003.
66.T. B. Massalski, Binary Alloy Phase Diagrams, ASM International, Materials Park, Ohio, Vol. 1, 1986, p. 917.