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系統識別號 U0026-2707201114570100
論文名稱(中文) 錫銀覆晶銲錫隆點之電遷移研究
論文名稱(英文) Electromigration in Flip Chip Sn2.6Ag Solder Bumps
校院名稱 成功大學
系所名稱(中) 材料科學及工程學系碩博士班
系所名稱(英) Department of Materials Science and Engineering
學年度 99
學期 2
出版年 100
研究生(中文) 鄧雯菁
研究生(英文) Wen-Jing Deng
電子信箱 N56984385@mail.ncku.edu.tw
學號 N56984385
學位類別 碩士
語文別 中文
論文頁數 88頁
口試委員 指導教授-林光隆
口試委員-陳貞夙
口試委員-高振宏
中文關鍵字 Electromigration  Cu pad  Current crowding  Wavelike 
英文關鍵字 電遷移  銅銲墊  電流擁擠效應  波浪狀 
學科別分類
中文摘要 電子產品輕薄短小、處理速度及功能提升的需求,促使電子元件微小化,採用之覆晶接合銲錫隆點(Flip Chip Solder Bump)的電流密度增加,使得電遷移以及熱遷移對覆晶銲錫隆點的影響更加顯著。電遷移會導致結構中孔洞的生成、銲錫中相的分離、突起物的形成及增進介金屬化合物的生成;許多缺陷將會導致底層金屬層的消耗及通電的失效,然而卻少有文獻探討基板端銅銲墊在通電過程中可能的失效行為。本研究探討錫銀覆晶接合銲錫隆點之電遷移行為,其於晶片端之底層金屬層為0.5 µm Ti/0.1 µm Cu/2 µm Ni,基板端則為20 µm銅銲墊,銲錫的直徑為140 µm,高度為105 µm。當覆晶銲錫隆點於環境溫度為150℃,電流密度為1×104 A/cm2通電後,陰極銅銲墊上出現不均勻之消耗,隨著通電時間的增加,銅銲墊在凹洞處有更快速的消耗。當銅銲墊作為陽極或是僅作時效熱處理時,銅銲墊的消耗並不顯著。本研究也針對通電所導致陰極銅銲墊的不均勻快速消耗提出建議機制,由於介金屬化合物厚度的差異與陰極銅銲墊不平整的表面,導致銅銲墊與銲錫界面上產生局部電流密度集中的區域,電遷移的極性效應也會加速銅銲墊在凹洞的消耗,隨著通電時間的增加,在銅銲墊上消耗較多的區域也逐漸成為大的凹洞,導致在通電478小時後,陰極銅銲墊在凹洞的消耗的深度可能到達20 µm,寬度則為40 µm。增加通電時間與增加電流密度皆會使銅銲墊局部電流密度集中之現象加劇,因此時間及電流密度會彼此增效(Synergise)局部電流集中的現象。
英文摘要 The miniaturization of package devices and the ever improvement in processing speed and function of the electronic products has lead to high current density for the flip chip solder bump. The increasing current density may give rise to electromigration and thermomigration to the solder bump. Electromigration has been found to cause void nucleation, phase separation of solder constituent elements, hillocks, and enhance IMC (Intermetallic Compound) formation. Many of these defects will cause consumption and failure to the thin UBM (Under Bump Metal) layers. Nevertheless, there has been few studies to investigate the possible failure of the bonding pad like thick Cu layer on the substrate side. The present study reported the electromigration in a commercial Sn-2.6Ag solder bump, with 0.5 µm Ti/0.1 µm Cu/2 µm Ni UBM. The dimension of the solder bump is 140 µm in diameter and 105 µm in height. The current stressing was conducted at a current density of 1.0×104 A/cm2 at 150℃, which induced uneven consumption of Cu pad. With increasing current stressing time, the consumption of the cathodic Cu pad accelerates at the extruded location. The consumption of the Cu pad was not prominent when the Cu acts as anode or under thermal annealing without current stressing. A schematic mechanism was proposed for illustrating the accelerate consumption of Cu pad caused by current stressing. The slightly rough interfacial structure of the Cu pad provides multiple local current crowding tips spreading at the Cu pad/solder interface. The polarity electromigration behavior at the cathodic interface accelerates the consumption of Cu pad at the tips which merge to large cavity after prolong current stressing. The cavities grow to 20 µm deep and 40 µm diameter at 478 hours of current stressing, indicating a serious local consumption of the 20 µm Cu pad when serves as cathode. With increasing current density or current stressing time, the effect of local current crowding increased. The effect of local current crowding is synergised by time and current density.
論文目次 中文摘要........................................................... I
英文摘要........................................................... II
總目錄...............................................................IV
表目錄...............................................................VI
圖目錄.............................................................VII
第壹章 簡介.........................................................1
1-1 電子構裝簡介與覆晶接合技術..........................1
1-2 界面反應........................................................4
1-2-1 Cu/Sn界面反應............................................4
1-2-2 Ni/Sn界面反應.............................................6
1-2-3 Cu/Sn/Ni界面反應........................................6
1-2-4 Cu/SnAgCu/Ni界面反應...............................10
1-3 電遷移效應及其對覆晶銲錫隆點之影響...........10
1-3-1 電遷移理論................................................11
1-3-2 電遷移效應對覆晶銲錫隆點之影響...............13
1-4 熱遷移效應對覆晶銲錫隆點之影響..................14
1-5 研究目的......................................................15
第貳章 實驗方法與步驟.......................................16
2-1 實驗構想......................................................16
2-2 電遷移實驗之試片.........................................16
2-3 電遷移實驗...................................................19
2-3-1 電遷移實驗之通電裝置與試片設置...............19
2-3-2 銲錫隆點之電子流方向...............................19
2-3-3 電遷移實驗條件.........................................19
2-4 試片分析......................................................24
第參章 結果與討論..............................................25
3-1 覆晶銲錫隆點之微觀結構觀察.........................25
3-2 不同溫度下通電之微觀結構比較......................30
3-3 不同電流密度下通電之微觀結構比較................41
3-3-1 電遷移對陰極金屬層之影響..........................41
3-3-2 介金屬化合物之生成與消長..........................45
3-4 電遷移效應對銲錫接點微觀結構之影響............48
3-4-1 基板端陰極銅銲墊之消耗.............................48
3-4-2 介金屬化合物之生成與消長...........................65
第肆章 結論.........................................................79
參考文獻.............................................................80
參考文獻 1. M. L. Minges, Electronic Materials Handbook, ASM International. Handbook Committee, 1989, Section 4.
2. J. H. Lau, Flip Chip Technologies, McGraw-Hill, New York, 1995, Chapter 1.
3. J. H. Lau, Flip Chip Technologies, McGraw-Hill, New York, 1995, Chapter 3.
4. H. Ashassi-Sorkhabi, H. Dolati, N. Parvini-Ahmadi and J. Manzoori, “Electroless deposition of Ni-Cu-P alloy and study of the influences of some parameters on the properties of deposits”, Applied Surface Science, Vol. 185, No. 3~4, 2002, pp. 155~160.
5. D. P. Yao and J. K. Shang, “Effect of Aging on Fatigue-Crack Growth at Sn-Pb/Cu Interfaces”, Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science, Vol. 26, No. 10, 1995, pp. 2677~2685.
6. K. N. Tu, “Cu/Sn interfacial reactions: Thin-film case versus bulk case”, Materials Chemistry and Physics, Vol. 46, No. 2~3 1996, pp. 217~223.
7. K. N. Tu and R. D. Thompson, “Kinetics of Interfacial Reaction in Bimetallic Cu-Sn Thin-Films”, Acta Metallurgica, Vol. 30, No. 5, 1982, pp. 947~952.
8. S. Bader, W. Gust and H. Hieber, “Rapid Formation of Intermetallic Compounds by Interdiffusion in the Cu-Sn and Ni-Sn Systems”, Acta Metallurgica Et Materialia, Vol. 43, No. 1, 1995, pp. 329~337.
9. T. B. Massaiski, Binary Alloy Phase Diagrams, ASM International, Materials Park, Ohio, Volume 1, 1986, p. 965.
10. W. J. Tomlinson and H. G. Rhodes, “Kinetics of Intermetallic Compound Growth between Nickel, Electroless Ni-P, Electroless Ni-B and Tin at 453-K to 493-K”, Journal of Materials Science, Vol. 22, No. 5, 1987, pp. 1769~1772.
11. C. Schmetterer, H. Flandorfer, C. Luef, A. Kodentsov and H. Ipser, “Cu-Ni-Sn: A Key System for Lead-Free Soldering”, Journal of Electronic Materials, Vol. 38, No. 1, 2009, pp. 10~24.
12. 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, No. 7, 2002, pp. 1612~1621.
13. T. M. Korhonen, P. Su, S. J. Hong, M. A. Korhonen and C. Y. Li, “Reactions of lead-free solders with CuNi metallizations”, Journal of Electronic Materials, Vol. 29, No. 10, 2000, pp. 1194~1199.
14. T. B. Massaiski, Binary Alloy Phase Diagrams, ASM International, Materials Park, Ohio, Volumn 2, 1986, p. 1759.
15. W. H. Wu, H. L. Chung, B. Z. Chen and C. E. Ho, “Critical Current Density for Inhibiting (Cu,Ni)(6)Sn-5 Formation on the Ni Side of Cu/Solder/Ni Joints”, Journal of Electronic Materials, Vol. 39, No. 12, 2010, pp. 2653~2661.
16. 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, No. 1~3, 2007, pp. 155~174.
17. M. Ding, G. T. Wang, B. Chao, P. S. Ho, P. Su and T. Uehling, “Effect of contact metallization on electromigration reliability of Pb-free solder joints”, Journal of Applied Physics, Vol. 99, No. 9, 2006, pp. 094906-1~094906-6.
18. International Roadmap for Semiconductor Technology,
Semiconductor Industry Association, San Jose, CA, 1999.
19. V. B. Fiks, “On the Mechanism of the Ion in Metals”, Soviet Physics, Solid State, Vol. 1, 1959, pp. 14~28.
20. H. B. Huntington and A. R. Grone, “Current-Induced Marker Motion in Gold Wires”, Journal of Physics and Chemistry of Solids, Vol. 20, 1961, pp. 76~87.
21. E. C. C. Yeh, W. J. Choi, K. N. Tu, P. Elenius and H. Balkan, “Current-crowding-induced electromigration failure in flip chip solder joints”, Applied Physics Letters, Vol. 80, No. 4, 2002, pp. 580~582.
22. L. Y. Zhang, S. Q. Ou, J. Huang, K. N. Tu, S. Gee and L. Nguyen, “Effect of current crowding on void propagation at the interface between intermetallic compound and solder in flip chip solder joints”, Applied Physics Letters, Vol. 88, No. 1, 2006, pp. 012106-1~012106-3.
23. Y. C. Hu, Y. H. Lin, C. R. Kao and K. N. Tu, “Electromigration failure in flip chip solder joints due to rapid dissolution of copper”, Journal of Materials Research, Vol. 18, No. 11, 2003, pp. 2544~2548.
24. J. Y. Song, J. Yu and T. Y. Lee, “Effects of reactive diffusion on stress evolution in Cu-Sn films”, Scripta Materialia, Vol. 51, No. 2, 2004, pp. 167~170.
25. J. W. Nah, K. Chen, K. N. Tu, B. R. Su and C. Chen, “Mechanism of electromigration-induced failure in flip-chip solder joints with a 10-um-thick Cu under-bump metallization”, Journal of Materials Research, Vol. 22, No. 3, 2007, pp. 763~769.
26. Y. S. Lai, Y. T. Chiu and J. Chen, “Electromigration reliability and morphologies of Cu pillar flip-chip solder joints with Cu substrate pad metallization”, Journal of Electronic Materials, Vol. 37, No. 10, 2008, pp. 1624~1630.
27. L. H. Xu, J. K. Han, J. J. Liang, K. N. Tu and Y. S. Lai, “Electromigration induced high fraction of compound formation in SnAgCu flip chip solder joints with copper column”, Applied Physics Letters, Vol. 92, No. 26, 2008, pp. 262104-1~262104-3.
28. K. Yamanaka, T. Ooyoshi and T. Nejime, “Effect of underfill on electromigration lifetime in flip chip joints”, Journal of Alloys and Compounds, Vol. 481, No. 1~2, 2009, pp. 659~663.
29. S. H. Chae, X. F. Zhang, K. H. Lu, H. L. Chao, P. S. Ho, M. Ding, P. Su, T. Uehling and L. N. Ramanathan, “Electromigration statistics and damage evolution for Pb-free solder joints with Cu and Ni UBM in plastic flip-chip packages”, Journal of Materials Science-Materials in Electronics, Vol. 18, No. 1~3, 2007, pp. 247~258.
30. Y. S. Lai, Y. T. Chiu and Y. H. Shao, “Electromigration of 96.5Sn-3Ag-0.5Cu Flip-chip Solder Bumps Bonded on Substrate Pads of Au/Ni/Cu or Cu Metallization”, Electronic Components and Technology Conference, 56th, 2006, pp. 641~645
31. Y. S. Lai, K. M. Chen, C. L. Kao, C. W. Lee and Y. T. Chiu, “Electromigration of Sn-37Pb and Sn-3Ag-1.5Cu/Sn-3Ag-0.5Cu composite flip-chip solder bumps with Ti/Ni(V)/Cu under bump metallurgy”, Microelectronics Reliability, Vol. 47, No. 8, 2007, pp. 1273~1279.
32. Y. H. Hsiao, H. W. Tseng and C. Y. Liu, “Electromigration-Induced Failure of Ni/Cu Bilayer Bond Pads Joined with Sn(Cu) Solders”, Journal of Electronic Materials, Vol. 38, No. 12, 2009, pp. 2573~2578.
33. H. W. Tseng, C. T. Lu, Y. H. Hsiao, P. L. Liao, Y. C. Chuang, T. Y. Chung and C. Y. Liu, “Electromigration-induced failures at Cu/Sn/Cu flip-chip joint interfaces”, Microelectronics Reliability, Vol. 50, No. 8, 2010, pp. 1159~1162.
34. Y. S. Lai and J. M. Song, “Electromigration Reliability with Respect to Cu Content in Solder Joint System”, Electronics Packaging Technology Conference, 10th, 2008, pp. 1160~1163.
35. W. H. Wu, H. L. Chung, C. N. Chen and C. E. Ho, “The Influence of Current Direction on the Cu-Ni Cross-Interaction in Cu/Sn/Ni Diffusion Couples”, Journal of Electronic Materials, Vol. 38, No. 12, 2009, pp. 2563~2572.
36. W. H. Wu, S. P. Peng, C. S. Lin and C. E. Ho, “Study of DC and AC Electromigration Behavior in Eutectic Pb-Sn Solder Joints”, Journal of Electronic Materials, Vol. 38, No. 10, 2009, pp. 2184~2193.
37. A. T. Huang, A. M. Gusak and K. N. Tu and Y. S. Lai, “Thermomigration in SnPb composite flip chip solder joints”, Applied Physics Letters, Vol. 88, No. 14, 2006, pp. 141911-1~141911-3.
38. J. W. Nah, J. O. Suh, K. N. Tu, S. W. Yoon, V. S. Rao, V. Kripesh and F. Hua, “Electromigration in flip chip solder joints having a thick Cu column bump and a shallow solder interconnect”, Journal of Applied Physics, Vol. 100, No. 12, 2006, pp. 123513-1~123513-5.
39. D. Q. Yu, C. M. L. Wu, D. P. He, N. Zhao, L. Wang and J. K. L. Lai, “Effects of Cu contents in Sn-Cu solder on the composition and morphology of intermetallic compounds at a solder/Ni interface”, Journal of Materials Research, Vol. 20, No. 8, 2005, pp. 2205~2212.
40. V. S. Donepudi, R. Venkatachalapathy, P. O. Ozemoyah, C. S. Johnson and J. Prakash, “Electrodeposition of copper from sulfate electrolytes - Effects of thiourea on resistivity and electrodeposition mechanism of copper”, Electrochemical and Solid State Letters, Vol. 4, No. 2, 2001, pp. C13~C16.
41. H. P. R. Frederikse, R. J. Fields and A. Feldman, “Thermal and Electrical-Properties of Copper-Tin and Nickel-Tin Intermetallics”, Journal of Applied Physics, Vol. 72, No. 7, 1992, pp. 2879~2882.
42. B. A. Cook, I. E. Anderson, J. L. Harringa and R. L. Terpstra, “Effect of heat treatment on the electrical resistivity of near-eutectic Sn-Ag-CuPb-free solder alloys”, Journal of Electronic Materials, Vol. 31, No. 11, 2002, pp. 1190~1194.
43. K. J. Puttlitz and K. A. Stalter, Handbook of Lead-Free Solder Technology of Microelectronic Assemblies, Marcel Dekker lnc, New York, 2004, pp. 284.
44. C. Kittle, An Introduction to Solid State Physics, Wiley, London/New York, 1976.
45. W. Zhou, L. J. Liu, B. L. Li and P. Wu, “Effect of Intermetallic on Electromigration and Atomic Diffusion in Cu/SnAg3.0Cu0.5/Cu Joints: Experimental and First-Principles Study”, Journal of Electronic Materials, Vol. 38, No. 6, 2009, pp. 866~872.
46. M. Paunovic and M. Schlesinger, Fundamentals of electrochemical deposition, John Wiley & Sons, New York, 2006, pp. 211~212.
47. F. A. Lowenheim, Electroplating, McGraw-Hill, New York, 1978, pp. 147..
48. J. W. Gallaway, D. Desai, A. Gaikwad, C. Corredor, S. Banerjee and D. Steingart, “A Lateral Microfluidic Cell for Imaging Electrodeposited Zinc near the Shorting Condition”, Journal of the Electrochemical Society, Vol. 157, No. 12, 2010, pp. A1279~A1286.
49. M. Harada and R. Satoh, “Mechanical Characteristics of 96.5Sn/3.5Ag Solder in Microbonding”, IEEE Transactions on Components Hybrids and Manufacturing Technology, Vol. 13, No. 4, 1990, pp. 736~742.
50. N. Jiang, J. A. Clum, R. R. Chromik and E. J. Cotts, “Thermal expansion of several Sn-based intermetallic compounds”, Scripta Materialia, Vol. 37, No. 12, 1997, pp. 1851~1854.
51. M. L. Minges, Electronic Materials Handbook, ASM International. Handbook Committee, 1989, pp. 58.
52. Handbook of SMT Producing Instructions, Beijing SMT Specialty Committee, 1998.
53. J. Emsley, The Elements, Clarendon Press, Oxford, 1998.
54. R. C. Weast, CRC Handbook of chemistry and physics, CRC Press Inc., Bota Racon, 1982.
55. F. Gao, J. M. Qu and T. Takemoto, “Additive Occupancy in the Cu6Sn5-Based Intermetallic Compound Between Sn-3.5Ag Solder and Cu Studied Using a First-Principles Approach”, Journal of Electronic Materials, Vol. 39, No. 4, 2010, pp. 426~432.
56. H. Yu, V. Vuorinen and J. Kivilahti, “Effect of ni on the formation of Cu6Sn5 and Cu3Sn intermetallics”, IEEE Transactions on Electronics Packaging Manufacturing, Vol. 30, No. 4, 2007, pp. 293~298.
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