臺灣博碩士論文加值系統

電子產品不斷朝著輕薄短小發展，擁有尺寸小與性能優異之覆晶技術逐漸成為封裝市場之主流。在覆晶技術相關之研究中，銲料凸塊與凸塊下金屬層間所發生之界面反應為重要課題之一。然而在封裝過程當中，產品會因外在環境與本身材質所影響，例如矽晶片與高分子基板之間由於熱膨脹數(coefficient of thermal expansion, CTE)差異較大，容易造成銲點熱應力之生成，而使產品產生變形。本研究主要探討於銅/錫薄膜界面反應，添加外加應力之因素，探討其影響。
於回銲研究中，將樣品置於260℃下，時間置於高溫爐10分鐘至95分鐘，以50分鐘為分界點訂為ts，ts以前為固態反應，ts以後為液固之反應，於45分鐘後，無應力下銅已經完全反應，經分析為Cu6Sn5，且於同時介金屬化合物已開始進行熟化之反應，且發現化合物剝離於界面處之現象產生，而於外加應力下，其熟化反應發生的時間比無應力下晚，之後隨時間增長，介金屬化合物尺寸持續增大，且介金屬化合物其形式為六角柱狀之形式，且以六角柱狀之剝離於界面處。藉由微結構之分析，提出介金屬化合物形態、成長與剝離之可能機制。
於固態熱處理研究中，將樣品置於120℃、150℃與170℃下進行熱處理1天∼40天，於不同之應力下，皆生成介金屬化合物Cu6Sn5，且於隨時間變長，於界面處所裸露出之鉭部分也持續增多，然而發現於外加應力之下所裸露之鉭部分比無應力下之所裸露之鉭部分多，根據微結構分析，提出介金屬化合物成長與熟化反應之機制。

With the electronic products becoming small, thin and light, the flip-chip technology is the trend of the package because of its small package size and excellent performance. The interfacial reaction between solder bump and under bump metallization is one of the important subjects in the flip chip reliability concerns. But at the process of microelectronic packaging, the electronic products that could be affected by the environment of the packaging and the property of products’s material could be strain. In this study, effect of applied stresses on the copper/tin thin film interfacial reaction can be dicussed.
In the study of reflow, the samples were reflowed at 260 ℃ for durations ranging from 10min to 95 min. We use the 50 min as the ts, before the ts can be solid state reaction and after the ts can be liquid solid raction .After 40min,under without applied stresses , the copper have be reactioned completely, the intermetallic Cu6Sn5 can detected and at 45min ,the intermetallic compound began ripening reaction. And we can found that the intermetallic compound have spallen from the interface. With the time gone, the sizes of the intermetallic compound can grow bigger ontinuously. The morphololgy of the intermetallic compounds is hexagonal and morphology of intermetallic compound spalling from the interface is hexagonal. Based on microstructural analyses, a possible mechanism for the growth, disappearance, and spalling of the intermetallic compounds was proposed.
In the study of isothermal solid-state aging, we put the sample in the oven, and solid-state aging at temperatures of 120℃, 150℃ and 170℃. The duration of solid-state aging is from 1day to 40day. Under different of applied stresses,it could product the same intermitallic compound. With time gone, the area of Ta from the interface become more and more. And under the applied stresses, the area of Ta from the interface can more than the area of Ta from the interface without the applied stresses. Based on microstructural analyses, a possible mechanism for the growth, disappearance, and spalling of the intermetallic compounds was proposed.

致謝---------------------------------------------------- Ⅰ
摘要---------------------------------------------------- Ⅱ
Abstract------------------------------------------------ Ⅲ
目次---------------------------------------------------- Ⅳ
表目次-------------------------------------------------- Ⅵ
圖目次-------------------------------------------------- Ⅶ
一、 前言----------------------------------------------- 1
二、 文獻回顧------------------------------------------- 2
（一） 覆晶封裝製程------------------------------------- 2
（二） 熱應力------------------------------------------- 5
（三） 相變化引發的應力--------------------------------- 8
（四） 外加應力---------------------------------------- 14
（五） 界面反應----------------------------------------- 19
（六）錫/銅界面反應------------------------------------- 20
（七）剝離現象------------------------------------------ 26
三、 實驗方法------------------------------------------- 30
（一） 樣品的製備--------------------------------------- 30
（二） 回焊實驗（液／固界面反應）---------------------- 34
（三） 熱處理（固／固界面反應）------------------------- 34
（四） 電子顯微鏡樣品的製備及分析----------------------- 34
（五） XRD繞射分析-------------------------------------- 35
四、 實驗結果與討論------------------------------------- 39
（一） 回焊反應（液／固界面反應）----------------------- 39
1. 無應力----------------------------------------------- 39
2. 外加應力(22 N/mm) ----------------------------------- 45
3. 外加應力(28 N/mm) ----------------------------------- 49
4. 介金屬化合物成長與剝離機制之討論--------------------- 53
（二）固態反應（固／固界面反應）------------------------ 58
1. 170℃熱處理------------------------------------------ 58
2. 150℃熱處理------------------------------------------ 63
3. 120℃熱處理------------------------------------------ 66
4. 熱處理介金屬化合物成長之討論------------------------- 69
五、 結論----------------------------------------------- 73
六、 參考文獻------------------------------------------- 74

1. 林文山、楊文彬，覆晶封裝底部封膠技術之研究，國立成功大學航空太空工程研究所碩士論文，2003年6月。
2. 盧慶儒，覆晶封裝製程技術之挑戰，DIGITIME科技網
3. Official Journal of the European Union, L37, P. 19 (2003)
4.汪建民，材料分析，p673-700，2005年3月。
5. S. L. Cheng, H. M. Lo, L. W. Cheng, S. M. Chang , and L. J. Chen, “Effects of stress on the interfacial reactions of metal thin films on (0 0 1)” Thin Solid Films, Vol. 424, pp. 33-39 (2003).
6. J. W. Jang, C. Y. Liu, P. G. Kim, K. N. Tu, A. K. Mal, and D. R. Frear, “Interfacial morphology and shear deformation of flip solder joints”,
Journal of Materials Research, Vol. 15(8), pp. 1679-1687 (2000).
7. B. W. Lee, J. Y. Kim, and D. Kwon, “Stress-strain Curve of Flip-Chip Solder Balls Based on Finite-Element Modeling of Thermal Displacements Measured by Electronic Speckle Pattern Interferometry”, Journal of Electronic Materials, Vol. 32(11), pp. 1322-1329 (2003).
8. P. Gergaud, M. Megdiche, O. Thomas, and B. Chenevier, “Influence of Si substrate orientation on stress development in Pd silicide films grown by solid-state reaction”, Applied Physics Letters, Vol. 83(7), pp. 1334-1336 (2003).
9. O. B. Loopstra, E. R. van Snek, Th. H. de Keijser, and E. J. Mittemeijer, “Stress and volume changes in amorphous Mo/Si multilayers on annealing”, Materials Science Forum , 154(Surface Layers), pp. 55-66 (1994).
10. P. Gergaud, O. Thomas, and B. Chenevier, “Stresses arising from a solid state reaction between palladium films and Si(001) investigated by in situ combined x-ray diffraction and curvature measurements ”Journal of Applied Physics, Vol. 94(3), pp. 1584-1591 (2003).
11. P. P. Buaud, F. M. D’Heurle, E. A. Irene, B. K. Patnaik, and N. R. Parikh, “In situ strain measurements during the formation of palladium silicide films”, Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structure, Vol. 9(5), pp. 2536-2541 (1991).
12. J. F. Jongste, P. F. A. Alkemade, G. C. A. M. Janssen, and S. Radelaar, “Kinetics of the formation of C49 TiSi2 from Ti-Si multilayers as observed by In situ stress measurements ”, Journal of Applied Physics, Vol. 74(6), pp. 3869-3879 (1993).
13. J. Y. Song and Jin Yu, “Effect of phosphorous content on phase transformation induced stress in Sn/Ni(P) ”Journal of Materials Research, Vol. 21(9), pp. 2261-2269 (2006).
14. J. Y. Song, Jin. Yu, and T. Y. Lee, “Effect of reactive diffusion on stress evolution in Cu-Sn films ”, Scripta Materialia, Vol. 51, pp. 167-170 (2004).
15 N. Karpe, K. Kyllesbech Larsen, and J.Bǿttiger, “Enhanced interdiffusion in amorphous nickel-zirconium thin films under tensile strain”, Philosophical Magazine B: Physics of of Condensed Matter: Statistical Mechanics, Electronic, Optical and Magnetic Properties, Vol. 66(4), pp. 507-512 (1992).
16. J. Y. Song, J. Yu, and T. Y. Lee, “ Analysis of phase transformation kinetics by intrinsic stress evolutions during the isothermal aging of amorphous Ni(P) and Sn/Ni(P) films ”, Journal of Materials Research, Vol. 19(4), pp. 1257-1264 (2004).
17. T. K. Hooghan, S. Nakahara, K. Hooghan, R. W. Privette, M. A. Bachman, R. S. Moyer, “Observation of amorphous chromium in modified C4 flip chip solder joints after thermal stress testing ”, Thin Solid Films, Vol. 437, pp. 235-241 (2003).
18. 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(9), pp. 948-957 (2004).
19. J. Y. Song and J. Yu, “Residual stress measurements in electroless plated Ni-P films ”, Thin Solid Films, Vol. 51, pp. 167-170(2002).
20. J. Y. Huh and S. J. Moon, “Effect of elastic stresses on solid-state amorphization of Zr/Co multilayers ”, Thin Solid Films, Vol. 377-378, pp. 611-616 (2000).
21. P. G. Shewmon, Diffusion in Solid, Second edition, The Metallurgical Society, Warrendale
22. T. Massalski, Binary Alloy Phase Diagrams, ASM, 1996
23. K. N. Tu, “Interdiffusion and reaction in bimetallic Cu-Sn thin films”, Acta Metallurgica Vol. 21(4), pp. 347-354 (1973)
24. B.S. Berry and I. Ames, “ Studies of SLT Chip Terminal Metallurgy ”, IBM Journal of Research and Development, Vol. 13(3), pp. 286 (1969).
25 A.A. Liu, H.K. Kim, and K.N. Tu, “Spalling of Cu6Sn5 spheroids in the soldering reaction of eutectic SnPb on Cr/Cu/Au thin films ”, Journal of Applied Physics, Vol. 80(5), p. 2774 (1996).
26 C.Y. Liu, H.K. Kim, and K.N. Tu, and P.A. Totta, “Dewetting of molten Sn on Au/Cu/Cr thin-film metallization ”, Applied Physics Letters, Vol. 69(26), pp. 4014 (1996)
27. Haimovich J. “Cu-Sn intermetallic compound growth in hot –air-levelled tin at and below 100℃”, AMP Journal of Technology, Vol. 3(11), pp. 46-54 (1993)
28. H.K. Kim, K.N. Tu, and P.A. Totta, “Ripening-assisted asymmetric spalling of Cu-Sn compound spheroids in solder joints on Si wafers ”, Applied Physics Letters, Vol. 68(16), pp. 2204 (1996).
29. Z. Mei, A. J. Sunwoo, and J. W. Morris. Jr, “Analysis of low-temperature intermetallic growth in copper-tin diffusion couples”, Metallurgical Transaction A, Vol. 23, pp. 857-864 (1992).
30. K. N. Tu and R. D. Thompson, “Kinetics of interfacial reaction in bimetallic copper-tin thin films”, Acta metall, Vol. 30, pp. 947-952 (1982).
31. S. Bader, W. Gust, and H. Hieber, “Rapid formation of intermetallic compounds by interdiffusion in the Cu-Sn and Ni-Sn systems”, Acta metal.mater. Vol. 43(1), pp. 329-337 (1995).
32. J. GÖrlich, G. Schmitz, and K. N. Tu, “On the mechanism of the binary Cu/Sn solder reaction ”, Applied Physics Letters, Vol. 86(5), pp.053106 (2005).
33. T. Takenaka, S. Kano, M. Kajihara, N. Kurokawa, and K. Sakamoto, “Growth behavior of compound layers Sn/Cu/Sn diffusion couples during annealing at 433-473K ”, Materials Science and Engineering A, Vol. 396, pp. 115-123 (2005).
34. K. N. Tu, T. Y. Lee, J. W. Jang, D. R. Frear, K. Zeng, and J. K. Kivilahti, “Wetting reaction versus solid state aging of eutectic SnPb on Cu”, Journal of Applied Physics, Vol. 89(9), pp. 4843-4849 (2001).
35. Gao. F. and Takemoto. T. “ Effects of addition participation in the interfacial reaction on the growth patterns of Cu6Sn5-based IMCs during reflow process”, Journal of Alloys and Compounds, Vol. 421,pp. 283-288 (2006)
36. J. S. Ha, T. S. Oh, and K. N. Tu, “Effect of supersaturation of Cu on reaction and intermetallic compound formation between Sn-Cu solder thin film metallization ”, Journal of Materials Research, Vol. 18(9), pp. 2109-2114 (2004).
37. H. C. Bhedwar, K. K. Ray, S. D. Kulkarni, and V. Balasubramanian. “Kirkendall effect studies in copper - tin diffusion couples”, Scripta Metallurgica, Vol. 6(10), pp. 919-922 (1972)
38. M. Oh, Doctoral Dissertation, Lehigh University (1994)
39. Riet. Labbie, Wouter Ruythooren, Jan Van Humbeeck, “Solid state diffusion in Cu-Sn and Ni-Sn diffusion couples with flip-chip scale dimensions”, Intermetallic Vol. 15, pp. 396-403 (2007)
40. B. Chao*, S. H. Chae, X. Zhang, K. H. Lu, J. Im, and P. S. Ho, “Investigation of diffusion and electromigration parameters for Cu-Sn intermetallic compounds in Pb-free solders using simulated annealing”, Act Materialia, Vol. (55), pp. 2805-2814 (2007)
41. T. Y. Lee, W. J. Choi, K. N. Tu, J. W. Jang, S. M. Kuo, J. K. Lin, D. R. Frear, K. Zeng, and J. K. Kiviahti, “Morphology, kinetics, and thermodynamics of solid-state aging of eutectic SnPb and Pb-free solders(Sn-3.5Ag, Sn-3.8Ag-0.7Cu and Sn-0.7Cu) on Cu”, Journal of Materials Research, Vol. 17(2), pp. 291-301 (2002)
42. K. N. Tu, A. M. Gusak, and M. Li, “Physics and materials challenges for lead-free solders”, Journal of applied physics, Vol. 93(3), pp. 1335-1353 (2003)
43. M. M. de Lima, Jr., R. G. Lacerda, J. Vilcarromero, and F. C. Marques, “Coefficient of thermal expansion and elastic modulus of thin films”, Journal of applied physics, Vol. 86(9), pp. 4936-4942 (1999)
44. 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(23), pp. 16027-16034 (1996)