Title page for 89321008


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Student Number 89321008
Author Li-Chan Shiau(蕭麗娟)
Author's Email Address No Public.
Statistics This thesis had been viewed 2572 times. Download 1569 times.
Department Chemical and Materials Engineering
Year 2001
Semester 2
Degree Master
Type of Document Master's Thesis
Language English
Title A study in the reactions between SnAgCu lead-free solders and Au/Ni surface finish in BGA packages.
Date of Defense 2002-06-27
Page Count 130
Keyword
  • Ball Grid Array Package
  • Interfacial Reactions
  • Lead-Free Solders
  • SnAgCu solders
  • Abstract ABSTRACT
    Lead-bearing solders, such as the PbSn eutectic, have been used extensively in the microelectronic industry for a long period of time. Recently, the European Union proposed to phase out the lead-bearing solders by January, 2008. Moreover, many major Japanese electronic companies, such as Panasonic and Fujitsu, have decided to switch voluntarily to lead-free processes by the year of 2002. It is generally believed that this lead-free transition is unevitable this time. Past research by the academia and industry indicated that a drop-in replacement for PbSn eutectic is difficult to find, if not impossible. Due to the extremely tight time schedule to go lead-free, the U.S. industry had reached a consensus to use SnAgCu series of solders to replace the PbSn eutectic, despite the fact that the literature for SnAgCu solders is still seriously lacking. The main objective of this proposal is then to study the reactions between such lead-free solders with the Au/Ni surface finish used in the industry.
    The SnAgCu solders are a series of solders with broad compositions. We propose to study the effect of the Cu concentration on the interfacial reation. The Au/Ni surface finish is the most common and important one for solder pads and bumps in the industry now. Therefore, the overall objective is to study in depth the reactions between the SnAgCu solders with various Cu concentration and the Au/Ni.
    The contact pads for solder balls on the PBGA substrates used in this study have the 0.8mm-Au / 8mm-Ni surface finish by electroplating. The solder composition, Sn-3.5Ag, Sn-3.5Ag-0.75Cu, Sn-xAg-0.5Cu (x=1/3/4 wt.% ), and Sn-3Ag-yCu (y=0/0.3/0.5/0.7/1 wt.%), were used, and their performances were compared. After reflow, the solder joints were subjected to aging at 180 oC for time up to 2500 hrs. The shear strengths of the solder joints with different aging time were then tested.
    It was found that the Cu concentration in the SnAgCu ternary solder has a very strong effect on the compound formation and the shear strength in solder joints with the Au/Ni surface finish. When there was no Cu (ex:Sn-3Ag), the reaction product was Ni3Sn4. When the Cu concentration was high (ex:Sn-3Ag-1Cu), the reaction product was (Cu1-p-qAupNiq)6Sn5 right after reflow, and two intermetallic compounds (Cu1-p-qAupNiq)6Sn5 and (Ni1-yCuy)3Sn4 formed after aging at 180oCfor 2500 hrs. When the Cu concentration was 0.5 wt.% (ex:Sn-3Ag-0.5Cu), both Ni3Sn4 and (Cu1-p-qAupNiq)6Sn5 were present near the interface right after reflow, and there was a layer of solder between these two intermetallic compounds. After aging, a layer of (Cu1-p-qAupNiq)6Sn5 over a layer of (Ni1-yCuy)3Sn4 formed at the interface.
    Table of Content 目   錄            頁數
    中文摘要I
    英文摘要III
    目  錄Ⅴ
    圖 目 錄VIII
    表 目 錄XV
    第 一 章 緒論
    1.1 研究背景1
    1.1.1 微電子封裝1
    1.1.2 球矩陣封裝(BGA)7
    1.1.3 銲接11
    1.1.4 無鉛銲料的現況15
    1.1.5 SnAgCu無鉛銲料19
    1.2 研究目的21
    第 二 章 文獻回顧
    2.1 37Pb-63Sn銲料與Au/Ni/Cu墊層反應文獻回顧22
    2.1.1 金脆效應22
    2.1.2介金屬種類30
    2.2 SnAgCu系列銲料文獻回顧34
    2.2.1 SnAg銲料與Au/Ni/Cu墊層反應34
    2.2.2 SnAgCu銲料與Au/Ni/Cu墊層反應37
    2.3 剪力強度測試文獻回顧38
      2.3.1 銲點可靠度38
      2.3.2 37Pb-63Sn剪力強度測試文獻回顧38
    2.4 實驗規劃41
    2.4.1 金相實驗規劃41
    2.4.2 剪力強度實驗規劃42
    第 三 章 實驗步驟與方法
    3.1 實驗預備43
    3.1.1 銲料的組成43
    3.1.2 實驗用Au/Ni/Cu墊層44
    3.1.3 實驗用迴銲曲線(Reflow Profile) 47
    3.2 實驗步驟50
      3.2.1 迴銲前BGA試片準備,及植上銲錫球50
    3.2.2 迴銲反應(Reflow) 實驗步驟50
    3.2.3 熱處理反應(Aging) 實驗步驟51
    3.3 金相分析51
    3.3.1 金相試片的製作51
    3.3.2 光學顯微鏡(OM)觀察52
      3.3.3 掃描式電子顯微鏡(SEM)觀察52
      3.3.4 電子探測分析儀(EPMA)組成分析53
    3.4 剪力強度分析54
    3.4.1 剪力強度測試程序54
    第 四 章 實驗結果
    4.1 銲料中不同Cu 含量的影響(一) 58
    4.1.1 迴銲後SEM界面金相觀察58
    4.1.2 熱處理後SEM界面金相觀察62
    4.1.3 剪力強度測試的實驗結果69
    4.2 銲料中不同Cu 含量的影響(二) 72
    4.2.1 迴銲後SEM界面金相觀察72
    4.2.2 熱處理後SEM界面金相觀察75
    4.2.3 剪力強度測試的實驗結果103
    4.3 銲料中不同Ag 含量的影響105
    4.3.1 迴銲後SEM界面金相觀察105
    4.3.2 熱處理後SEM界面金相觀察107
    4.3.3 剪力強度測試的實驗結果109
    第 五 章 討論與結論
    5.1 銲料中不同Cu 含量的影響112
      5.1.1 Au脆效應112
      5.1.2 介金屬種類的變化113
    5.1.3 Ni層消耗113
    5.1.4剪力強度測試的實驗結果114
    5.2 銲料中不同Ag 含量的影響117
      5.2.1介金屬種類的變化117
      5.2.2剪力強度測試的實驗結果117
    參考文獻118
    Reference 參考文獻
    [AND]I. E. Anderson, F. G. Yost, J. F. Smith, C. M. Miller, and R. L. Terpstra, United States Patent, Patent No.5527628, 1996.
    [BAN]K. Banerji, R. F. Darveaux, P. K. Liaw, R. Viswanathan, K. L. Murty, E. P. Simonen, and D. Frear, Microstructures and Mechanical Properties of Aging Materials, TMS, Warrendale, Pa., p.431, 1993.
    [CIR]Circuits Assembly, IC Insights, 1999.
    [COY]R. J. Coyle, P. P. Solan, A. J. Serafino, and S. A. Gahr, Proceedings of 50th Electronic Components and Technology Conference, Las Vegas, NV, USA, September, p.160, 2000.
    [DAR]R. F. Darveaux, K. Banerji, A. Mawer, and G. Dody, Ball Grid Array Technology, ed. J. K. Lau, (New York, McGraw-Hill, 1995), p.379.
    [DOD]G. Dody and T. Burnette, Surf. Mount. Tech., p.39, May, 1996.
    [FOS]   F. G. Foster, ASTM STP 319, p.13, 1962.
    [HAR1]W. B. O’Hara and W. C. Lee, Surf. Mount. Tech., p.44, January 1996.
    [HAR2]W. B. O’Hara and W. C. Lee, Int. J. Microcircuits and Elect. Packaging, 19, p.190, 1996.
    [HO1]C. E. Ho, Y. M. Chen, and C. R. Kao, J. Electron. Mater., 28, p.1231, 1999.
    [HO2]C. E. Ho, R. Zheng, G. L. Luo, A. H. Lin, and C. R. Kao, J. Electron. Mater., 29, p.1175, 2000.
    [HO3]   C. E. Ho, W. T. Chen, and C. R. Kao, J. Electron. Mater., 30, p.379, 2001.
    [HUN]S. C. Hung, P. J. Zheng, S. C. Lee, Proc. 24th IEMT, p.23, 1999.
    [IPC]IPC Roadmap for Lead-Free Electronics Assemblies, 2nd draft, IPC, Northbrook, IL, November 1999.
    [LEE]N. C. Lee, Soldering & Surface Mount Technology, No. 26, p.65, 1997.
    [LIU]C. M. Liu, C. E. Ho, W. T. Chen, and C. R. Kao, in press, J. Electron. Maters., 2001.
    [LU]S. W. Lu, R. H. Uang, K. C. Chen, H. T. Hu, L. C. Kung, and H. C. Hung, IEEE/CPMT Int’1 Electronic Manufacturing Technology Symposium, p.127, April, 1999.
    [MEI]Z. Mei, M. Kaufmann, A. Eslambolchi, and P. Johnson, Proc. 48th IEEE Electron. Comp. Tech. Conf., p.952, 1998.
    [MOO]K. W. Moon, W. J. Boettinger, U. R. Kattner, F. S. Biancaniello, and C. A. Handwerker, J. Electron. Mater., 29, p.1122, 2000.
    [MOR]J. E. Morris, Workshop, “The Design and Processing Technology of Electronic Packaging”, 1997.
    [NCM]Lead-Free Solder Project Final Report, NCMS Report 0401RE96, National Center for Manufacturing Sciences, 3025 Boardwalk, Ann Arbor, Michigan, 1997.
    [NEM]National Electronics Manufacturing Initiative (NEMI) Lead-Free Readiness Task Force Report, NEMI, 1999.
    [KAN1]S. K. Kang and V. Ramachandran, Scripta Metall., 14, p.421, 1980.
    [KAN2]S. K. Kang, R. S. Rai and S. Purushothaman, J. Electron. Mater., 25, p.1113, 1996.
    [PCI]Printed Circuits Federation/International Tin Research Institute Joint Statement, PCIF/ITRI, 1999.
    [SEN]Senate Bills S.729 and S.2637 by Senator Reid;House Bills H.2479 and H.2922 by Representative Cardin.
    [SUB]K. N. Subramanian, T. R. Bieler, and J. P. Lucas, J. Electron. Mater., 28, p.1176, 1999.
    [TRU]B. Trumble, IEEE Spectrum, p.55, 1998.
    [WIL]R. N. Wild, NEPCON, p.198, 1968.
    [YAM]M. Yamashita, S. Tada, and K. Shlokawa, United States Patent, Patent No. US 6179935 B1, 2001.
    [ZRI]A. Zribi, R. R. Chromik, R. Presthus, K. Teed, L. Zavalij, J. DeVita, J. Tova, E. J. Cotts, J. Clum, R. Erich, A. Primavera, G. Westby, R. J. Coyle, and G. M. Wenger, IEEE Electron. Comp. Tech., 23, p.383, 2000.
    [咎世蓉]咎世蓉, “無鉛銲錫之可靠度試驗”, 電子與材料, 第9期, p.96。
    [高振宏]高振宏, 何政恩, “一種可抑制易脆之Au介金屬於銲點中生成之新技術,” 中華民國專利, No.471988。
    [林志豪]林志豪碩士論文, 清華大學材料科學及工程研究所, 2000。
    [林安宏]林安宏碩士論文, 中央大學化學工程研究所, 2001。
    [黃家緯]黃家緯碩士論文, 成功大學材料科學及工程研究所, 2000。
    [陳國銓]陳國銓, IC封裝技術, 工業材料, 第158期, p.78, 2000。
    [謝宗雍] 謝宗雍, 陳力俊,“微電子材料與製程”, 中國材料科學學會, p.385, 2000。
    [張淑如]  張淑如,“鉛對人體的危害”, 勞工安全衛生簡訊, 第12期, p.17, 1995。
    [彭錢塘]  彭錢塘,“電路板無鉛銲墊之現況”, 電路板會刊, 第12期, p.75,
    [梁元彰]  梁元彰,“無鉛銲錫合金概況”, 電腦與通訊, 第90期, p.45, 2000。
    [賴玄金]賴玄金, 電子與材料, 第8期, p.111, 2000。
    [劉家明]劉家明碩士論文, 中央大學化學工程研究所, 2000。
    Advisor
  • C. R. Kao(高振宏)
  • Files
  • 89321008.pdf
  • approve immediately
    Date of Submission 2002-07-18

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