在電子構裝研究上，Cu是最常使用的材料，本研究探討Cu添加微量Fe元素(2.2 wt.%)形成銅鐵合金(C194)與Cu添加微量Be元素(2 wt.%)形成銅鈹合金(Alloy 25)；C194具有高強度、微細化結晶構造、耐蝕性強、良好焊接性等優點，而Alloy 25具有抗磨損性，高硬度和低摩擦性和耐腐蝕性等優點，且在與銲料接合時效處理時也可增加其耐疲勞度。
無鉛銲料目前的發展，常見到以Sn當基底元素。因此本研究利用掃描電子顯微鏡(SEM)並搭配能量散射光譜儀(EDS)和電子微探分析儀(EPMA)等顯微儀器，深入探討Sn-0.7 wt.% Cu無鉛銲料與C194和Alloy 25基材在反應溫度240、255和270 ℃下，反應時間0.5至10小時之液固界面反應，探究其界面反應生成金屬間化合物(intermetallic compound，IMC)的型態、種類、成長速率和擴散機制。
研究結果顯示SC/C194反應偶在反應溫度240、255和270 ℃下，其界面處生成兩種IMC，為(Cu, Fe)6Sn5和厚度十分薄之(Cu, Fe)3Sn相，反應時間來到2小時，C194基材中的Fe原子為良好的成核點，異質成核造成了(Cu, Fe)6Sn5散佈情況的發生，當反應時間和溫度增加時，金屬間化合物的總厚度增加，會有大量散佈的情況出現，此反應偶的介金屬相成長厚度與反應時間呈斜直線關係，反應機制為反應控制所主導。
SC/Alloy 25反應偶在反應溫度240、255和270 ℃下，界面皆有(Cu, Be)3Sn和(Cu, Be)6Sn5相的生成，隨者反應時間的增加，會觀察到(Cu, Be)6Sn5相有分層，且反應溫度270 ℃反應時間7.5 h時，(Cu, Be)6Sn5相發生晶粒熟化，當晶粒合併至一定大小無法再合併時，只能藉由脫離IMC表面以降低表面能，使系統趨向於穩定，而發生脫離現象，動力學方面，此反應偶的(Cu, Be)6Sn5相在反應溫度240、255和270 ℃下，皆為晶界擴散所控制，而除了(Cu, Be)3Sn相在240 ℃下反應時間0.5~2 h由晶界擴散所主導，其餘各(Cu, Be)3Sn相厚度皆符合斜直線關係，受反應擴散所控制，(Cu, Be)6Sn5相在各反應溫度下則是受限於晶界控制。

In electronic packaging research, Cu is the most commonly used substrate. This study will explore the interfacial reaction of solder and the Cu-base substrate. There are two substrate used in this study, included Cu added minor Fe elements (2.2 wt.%) to become copper-iron alloys (C194), and Cu added minor Be elements (2 wt.%%) to become copper-beryllium alloys (Alloy 25). C194 has better properties of high strength, refined crystal structure, strong corrosion resistance and well solderability. On the other hand, Alloy 25 has the advantages of abrasion resistance, high hardness, low coefficient of friction and good corrosion resistance. Besides it can also increase its fatigue resistance during the solder aging treatment.
As current development of lead-free solder, Sn-base solder is commonly used. Therefore, this study used Scanning Electron Microscope (SEM), Energy Dispersive Spectrometer (EDS) to discuss the interfacial reaction between Sn-0.7 wt. %Cu (SC)/C194 and Sn-0.7 wt. %Cu (SC)/Alloy 25 at 240, 255 and 270 ℃. The liquid-solid interfacial reaction with a reaction time of 0.5 to 10 hours will be lead. Explore the phase, type, growth rate and diffusion mechanism of intermetallic compound (IMC) generated by the interfacial reaction.
The results show that at 240, 255 and 270 ℃, in the SC/C194 reaction couple, (Cu, Fe)6Sn5 and a thin layer of (Cu, Fe)3Sn phase will form at the interface. When the reaction time reach 2 h, (Cu, Fe)6Sn5 phase start to spalling. As the reaction time and temperature increasing, the total thickness of the intermetallic compound increases, and a large amount of spalling occurs. The thickness of IMC has an oblique linear relationship to the reaction time, and the reaction mechanism is dominated by reaction control.
The SC/Alloy 25 reaction couples at 240, 255 and 270 ℃, (Cu, Be)3Sn and (Cu, Be)6Sn5 phases are formed at the interface. As the reaction time increases, Stratification of (Cu, Be)6Sn5 phase will be observed. As the reaction temperature raise to 270 ℃, and the reaction time reach 7.5 h, (Cu, Be)6Sn5 phase start to grain ripen. When the grains merge to its limit, they can only be separated from the IMC surface to reduce the surface energy and let the system tends to be stable, In terms of kinetics, (Cu, Be)6Sn5 phase in this reaction couple is controlled by the grain boundary diffusion at 240, 255 and 270 ℃. Except for (Cu, Be)3Sn phase at 240 ℃, the reaction time of 0.5~2 h is dominated by the boundary diffusion, the thickness of other (Cu, Be)3Sn phases are in the oblique linear relationship and are control by reaction diffusion, (Cu, Be)6Sn5 phase is limited by the grain boundary control at each reaction temperature.

[1] E.S.Freitas, W.R.Osório, J.E.Spinelli and A.Garcia, J. Mater. Res., 54, 1392-1400 (2014).
[2] G.D.Li, Y.W.Shi, H.Hao, Z.D.Xia, Y.P.Lei and F.Guo, J. Alloys Compd., 491, 382-385 (2010).
[3] X.P.Xiao, H.Xu, J.S.Chen, Q.Liang, J.F.Wang and J.BZhang, Mater. Res. Express, 4, 116511 (2017).
[4] J.S.Chang and Y.W.Yen, in 2018 International Conference on Electronics Packaging and iMAPS All Asia Conference (ICEP-IAAC) (2018), 97-101.
[5] K.Zeng and K.N.Tu, Mater. Sci. Eng.:R, 38, 55-105 (2002).
[6] N.Saunders and A.P.Miodownik, Bull. Alloy Phase Diagrams, 11, 278-287 (1990).
[7] A.K.Gain and L.C.Zhang, Microelectron. Reliab., 87, 278-285 (2018).
[8] 趙寧, 王建輝, 潘學民, 馬海濤 and 王來, 大連理工大學學報, 48, 661-667 (2008).
[9] Jeong-Won J.W.Yoon, Hyun-Suk H.S.Chun and Seung-Boo S.B.Jung, Curr. Opin. Solid State, 5, 55-64 (2001).
[10] S.H.Huh, K.S.Kim and K.Suganuma, Mater. Trans., 42, 739-744 (2001).
[11] A.J.Hickl and R.W.Heckel, Metall. Trans. A, 6, 431 (1975).
[12] V.I.Dybkov, J. Mater. Res., 21, 3078-3084 (1986).
[13] C.L.Tsao and S.W.Chen, J. Mater. Sci., 30, 5215-5222 (1995).
[14] G.V.Kidson, J. Nucl. Mater., 3, 21-29 (1961).
[15] D.A.Porter and K.E.Easterling, Cheltenham, Stanley Thornes Ltd.
[16] M.J.Rizvi, H.Lu and C.Bailey, Thin Solid Films, 517, 1686-1689 (2009).
[17] D.A.Porter and K.E.Easterling, Phase transformations in metals and alloys (revised reprint), ed, (CRC press, 2009).
[18] R.H.Robert E and R.Abbaschian and L.Abbaschian, Physical metallurgy principles, ed, (Van Nostrand New York, 1973).
[19] R.W.Balluffi, Metall. Trans. B, 13, 527-553 (1982).
[20] M.Schaefer, R.A.Fournelle and J.Liang, J. Electron. Mater., 27, 1167-1176 (1998).
[21] H.K.Kim and K.N.Tu, Phys. Rev. B, 53, 16027 (1996).
[22] M.Perez, Scr. Mater., 52, 709-712 (2005).
[23] W.Gust and H.Hieber S.Bader, Acta metallurgica et materialia, 43, 329-337 (1995).
[24] S.J.Wang and C.Y.Liu S.C.Hsu, Journal of electronic materials, 32, 1214-1221 (2003).
[25] S.J.Wang, National Central University, (2006).
[26] Y.Q.Lai, X.W.Hu, Y.L.Li and X.G.Jiang, J. Mater. Sci.: Mater. Electron., 29, 11314-11324 (2018).
[27] M. F.Arenas and V.L. Acoff, J. Mater. Res., 33, 1452 (2004).
[28] X.W.Hu, Y.L.Li, Y.Liu and Z.X.Min, J. Alloys Compd., 625, 241-250 (2015).
[29] H. T. Ma, J. Wang, L. Qu, L. L. An, L. Y. Gu, M. L. Huang, “The study on the rapidly-solidified Sn-0.7Cu lead-free solders and the interface reactions with Cu substrate”, 13th International Conference on Electronic Packaging Technology & High Density Packaging. 361-365 (2012).
[30] S.Tian, S.Li, J.Zhou, F.Xue, R.Cao and W.Fengjiang, J. Mater. Sci.: Mater. Electron., 28, 16120-16132 (2017).
[31] K.S.Bae and S.J.Kim, J. Mater. Res., 17, 743-746 (2002).
[32] X.C.Xie, X.C.Zhao, Y.Liu, J.W.Cheng, B.Zheng and Y.Gu, in Materials Science Forum (2015), 129-134.
[33] Y.C.Li, C.H.Chang, A.Pasana and H.M.Hsiao and Y.W.Yen, Journal of Electronic Materials, 50, 903-913 (2021).
[34] H.R.Ma, Y.P.Wang, J.Chen, H.T.Ma and N.Zhao, in 2017 18th International Conference on Electronic Packaging Technology (ICEPT) (2017), 1402-1405.
[35] H.Le and M.Jusheng H.Fuxiang, in International Symposium on Electronic Materials and Packaging (EMAP2000)(Cat. No. 00EX458) (2000), 391-393.
[36] H.Cao, J.Y.Min, S.D.Wu, A.P.Xian and J.K.Shang, J. Mater. Sci, 431, 86-91 (2006).
[37] K.Kita, K.Kobayashi and R.Monzen, Zairyo, 49, 482-487 (2000).
[38] G.D.Li, Y.W.Shi, H.Hao, Z.D.Xia, Y.P.Lei and F.Guo, Trans. Nonferrous Met. Soc. China, 17, s1081-s1084 (2007).
[39] C.Y.Chou, S.W.Chen and Y.S.Chang, J. Mater. Res., 21, 1849-1856 (2006).
[40] M.L.Huang X.Y.Liu, N.Zhao and L. Wang, Journal of Materials Science: Materials in Electronics, 25, 328-337 (2014).
[41] W.M.Chen, S.C.Yang, M.H.Tsai and C.R.Kao, Scr. Mater., 63, 47-49 (2010).
[42] N.Mookam, P.Tunthawiroon and K.Kanlayasiri, in IOP Conf. Ser. Mater. Sci. Eng (2018), 012008.
[43] S.K.Lin, H.Chen, W.K.Liou and Y.W.Yen, J. Mater. Res., 25, 2278-2286 (2010).
[44] E.Ganin, B.Z.Weiss and Y.Komem, Metall. Trans. A, 17, 1885-1890 (1986).
[45] Y.W.Yen, W.T.Chou, Y.U.Tseng, C.P.Lee and C.L.Hsu, J. Electron. Mater., 37, 73-83 (2008).
[46] Y.W.Yen, C.Y.Lee, M.H.Kuo, K.S.Chao and K.D.Chen, J. Electron. Mater., 100, 672-676 (2009).