隨著可攜式電子產品和通訊儀器的快速發展，都趨向於輕、薄、短、小的特性發展，所以電子封裝也朝著這方向而努力發展。而晶圓級封裝(WLP)因為輕薄短小的特性已經廣泛的應用在可攜式電子產品上；預估其將在未來成為主流趨勢。而在使用可攜式電子產品會對其封裝體內部造成隨機且低頻的震動，因此會對儀器產生累積的損傷，所以對封裝體進行反覆負載的研究愈來愈受重視。
本文利用有限元素分析和實驗兩者並行研究Ultra CSP在循環彎曲負載測試下的可靠度壽命，利用四點循環彎曲並改變振幅和頻率參數進行實驗。並對晶片進行失效分析，觀看其失效機制。最後利用有限元素分析軟體進行擬靜態分析。計算錫鉛球所受每循環週期下的彎曲循環負載的累積應變能密度；並對照實驗結果帶入Coffin-Manson經驗公式以其能預測可靠度壽命。
由有限元素分析發現在外圍對角線的角落得錫鉛球承受較大的累積應變能，所以此處的錫鉛球較易產生裂縫導致晶片阻值升高而失效，這和失效分析結果相吻合。由實驗中發現頻率參數對可靠度壽命影響並不明顯，反觀振幅參數有顯著的影響關係。並由實驗和分析結果找到Ultra CSP在四點循環彎曲下的可靠度壽命預測經驗公式 。

According to the fast development of portable electronic devices, their characteristics are inclined to miniature profile and lightweight. Nowadays, the wafer-level package (WLP) has been widely applied in portable electronic devices for its miniature profile and lightweight. It will become the mainstream trend later soon. The normal use of portable electronic devices brings low-frequency random vibrations to the electronic packages inside. Because of the increasing demand of these devices, the reliability of electronic packages subjected to repeated mechanical loads has become an important issue in the contemporary electronic packaging industry.
In this paper both numerical and experimental studies were carried out to investigate the reliability life of Ultra-CSP under cyclic bending conditions. We perform four-point cyclic bending with various combinations of amplitudes and frequencies. Then, we do failure analysis in Ultra-CSP by observing the failure modes. A finite element model for the package is built up for dynamic as well as quasi-static analyses. Accumulated plastic work per bending cycle within the critical solder ball were calculated and together with the experimental results the parameters for the Coffin-Manson fatigue equation were fitted.
Through finite element analysis we find that the solder ball which located in the corner has higher accumulated plastic work. Therefore, the crack in the solder ball grew more easily. Thus it lets package resistance rise to determine failure. It was observed from the bending experiments that the influence of frequencies on the fatigue life of the solder interconnects is inapparent. However, influence of amplitude is significant. From the results of both experiments and FEA, it was found that for this particular ultra-CSP specimen under cyclic bending conditions, the characteristic life was expressed as

目錄
目錄……………………………………………………………………….I
表目錄…………………………………………………………………....IV
圖目錄…………………………………………………………………....V
摘要……………………………………………………………….…..….IX
Abstract……………………………………………………………...……X
第一章 簡介………………………………………………….………....1
1-1 前言……………………………………………….…………1
1-2 文獻回顧………………………………………….…………2
1-3 組織與章節……………………………………….…………4
第二章 WLP和可靠度介紹………………………………….………...5
2-1 WLP簡介…………………………………………….……….5
2-1-1 WLCSP簡介………………………………….………6
2-1-2 Ultra CSP簡介………………………………….…….8
2-1-3 WLCSP和Ultra CSP兩者之差異…………….……10
2-2 可靠度介紹…………………………………………….…….11
2-2-1 韋伯分佈……………………………………….…….12
第三章 實驗部分……………………………………………….……...19
3-1 實驗治具設計………………………………………….….....19
3-1-1 JEDEC規範介紹………………….………………....19
3-1-2 治具設計………………………………………….....20
3-2 SMT上板作業…………………………………………...….21
3-2-1 設備介紹……….…………………...……..…….…..22
3-2-2 晶片介紹…………………………………..…….…..23
3-2-3 測試板介紹………………………………..…...……23
3-2-4 上板流程…………………………………....….……24
3-3 彎曲循環測試…………………………………....….……....25
3-3-1 位移振幅與頻率…………………..……..….……....27
3-3-2 試體分組…………………………..……..……….....28
3-3-3 設備介紹……………………………..…..……….....28
3-3-4 實驗步驟……………………………..…..……….....29
3-4 紅染料試驗………………………………..…..……..…….…30
3-4-1 設備介紹………………………..…..……..…….…..30
3-4-2 實驗步驟………………………..……..…..…….…..31
3-5 掃描式電子顯微鏡(SEM)觀察…………..…..……..….……32
3-5-1 設備介紹………………………..……..…..…….…..32
3-5-2 實驗步驟………………………..……..…..………...32
第四章 有限元素分析………………………..………….…………...50
4-1 有限元素分析求解理論……………..……….....………….50
4-1-1 非線性理論分析……………..………….…………..50
4-1-2 材料性質……………..………..…………………….51
4-2 基本假設……………..………..………………………….…53
4-3 ANSYS模擬分析……..………..………………………….….54
4-3-1 前處理模式…..………..……………………….……55
4-3-2 運算求解……..………..……………………….……56
4-3-3 後處理模式……..………..…………………….……57
第五章 結果與討論……..………..………………….………..…...….63
5-1 實驗結果討論..………..……………………………….…....63
5-1-1 實驗失效歷程…..…………………………………...63
5-1-2 韋伯分佈可靠度分析……………………………….65
5-1-3 紅染料實驗失效分析……………………………….68
5-1-4 SEM電子顯微鏡觀測……………….……………….68
5-2 有限元素模擬分析……………….…………………….…...69
第六章 結論與未來展望……………….………………………….….90
6-1 結論……………….…………………………………….…….90
6-2 未來展望……………….……………………………….…….91
參考文獻……………….…………………………………………..……92

參考文獻
[1] M.S. Liang, S.C. Hung, P.J. Zheng, and H.N. Chen, “Reliability and Failure Analyses of PBGA Assemblies under Bending Cyclic Test”,Proceeding of SEMICON Taiwan, pp. 145-151,1999.
[2] S.H. Ho, P.J. Zheng, J.D. Wu, and S.C. Hung, “On the Reliability and Failure of PBGA Interconnects under Bending Cyclic test”, Proceeding of IMPAS 2000, 2000.
[3] T.C. Huang, D.P. Lai, S.H. Ho, Jo Lee, P.J. Zheng, J.G. Hwang, and J.D. Wu,“Reliability and Failure Analysis of CSP under Bending Cycling Test”, Proceeding of IMPAS 2000, 2000.
[4] P.J. Zheng, Rick Chen, Alex Lee and S.C. Hung, “Reliability and Failure analysis of BCC Assembly under Bending Cyclic Test”, Advanced Semiconductor Engineering, Inc, Kaohsiung TAIWAN, 1999.
[5] M.S. Liang, P.J. Zheng, A. Lee, and S.C. Hung, “Reliability and Failure analysis of μBGA under Bending Cyclic Test”, Report No. 520-CHAR-BLRT-9905-01, Advanced Semiconductor Engineering, Inc, Kaohsiung TAIWAN, 1999.
[6] Q. Yu, and M. Shiratori,“Thermal Fatigue Reliability Assessment for Solder Joints of BGA Assembly”, Advances in Electronic Packaging, 26-1, 239-246, 1999.
[7] J.D. Wu, S.H. Ho, P.J. Zheng, C.C. Liao, and S.C. Hung,“An Experimental Study of Failure and Fatigue Life of a Stacked CSP Subjected to Cyclic Bending”, Proceeding of ECTC 2001.
[8] Akito Yoshida and Isao Kudo,“ Board level Reliability for Laminate CSP ”Proceeding of IEEE,1998.
[9] Xing Huang ,S.-W.Ricky ,Chien Chun Yan ,and Sam Hui, “Characterization and Analysis on the Solder Ball shear Testing Conditions”, Proceeding of ECTC 2001 51st , 29 May-1 June 2001,pp.1065–1071.
[10] S. Shetty ,V. Lehtien ,A. Dasgupta ,V. Halkola ,and T.Reinikainen,“Fatigue of Chip Scale Package Interconnects Due to Cyclic Bending”, Transactions of the ASME,Vol.123,September 2001.
[11] Bret A. Zahn ,“Solder Joint Fatigue Life Model Methodology for 63Sn37Pb and 95.4Sn4Ag0.5Cu Materials”,Electronic Components and Technology Conference,2003,pp.83-94.
[12] Zahn, B. A., “Impact of Ball Via Configurations on Solder Joint Reliability in Tape Based Chip-scale Packages,” Proc 52nd Electronic Components and Technology Conf, San Diego, CA, May. 2002.
[13] 洪松井、黃凱，“晶圓級晶片尺寸封裝技術之概述”，電子與材料雜誌，第12期，101~107，2001。
[14] 劉智強，“無鉛Ultra CSP電子元件之可靠度測試改善”，國立中山大學機械與機電工程學研究所碩士論文，(2004)
[15] 駱韋仲,“晶圓級構裝技術”，電子與材料雜誌，第14期，41~48, 2002。
[16] JEDEC,“Motonic and Cyclic Bend Test Standard”, 10/28/2002.
[17] John H. Lau, Yi-Hsin Pao,“Solider Joint Reliability of BGA,CSP,Flip Chip,and Fine Pitch SMT Assemblies”,Mcgrew-Hill.
[18] 陳耀茂,“可靠度工程-方法與應用”,五南圖書出版公司。
[19] 劉立晟,“覆晶錫球陣列封裝之無鉛錫球接點可靠度測試”,國立中山大學機械與機電工程學研究所碩士論文,(2003)。
[20] 郭昱綸,“覆晶球柵陣列電子封裝體在溫度循環下的熱應力與熱應變關係”,國立中山大學機械與機電工程學研究所碩士論文,(2003)。
[21] Steffen wiese ,Sven Rzcpka, Ekkehard Meusel, “Time-independent Plastic Behaviour of Solders and its Effect on FEM Simulations for Electronics Packages”, Proceeding of IEEE,2002.
[22] Darveaux, R.,“Effect of Simulation Methodology on Solder Joint Crack Growth Correlation and Fatigue Life Prediction,” J. Electr. Pack., ASME, Vol. 124, No. 3 (2002), pp. 147-154.
[23] Shetty, S. et al, “Fatigue of Chip Scale Package Interconnects due to Cyclic Bending,” J. Electr. Pack., ASME, Vol. 123, No. 3 (2001), pp. 302-308.
[24] Ross, C. A. et al, “Effects of Strain Rate on Concrete Strength,” ACI Materials Journal, Vol. 92, No. 1 (1995), pp. 37-47.