臺灣博碩士論文加值系統

自電子產品中移除含鉛Sn-Pb材料而需要找到適當無鉛合金來取代，可以肯定的，錫-銀/錫-銀-銅合金將成為未來應用在IC封裝上之無鉛錫球的主流材料；因而錫球黏著IC、組合於基板或PCB上受不同溫度循環測試所產生之塑-潛變行為將分別加以分析與探討，尤其錫-銀/錫-銀-銅合金的熔點比錫-鉛合金高出30℃之多，這些因素將導致相當大之塑性與潛變行為的差異。
本文使用有限元素分析對三種無鉛銲料及一含鉛材料受兩種不同溫度循環負載作用，探討WLCSP組合於PCB上之彈-塑性-潛變行為與特性，其結果可得：(1) 彈性應變效應對這四種錫球材料之熱機械行為的影響是很微小的。(2) 對96.5Sn-3.5Ag來說，其剪應變範圍的貢獻幾乎由塑性應變效應提供，也即96.5Sn-3.5Ag承受潛變能力最強。(3) 95.5Sn-3.8Ag-0.7Cu及63Sn-37Pb的塑性或潛應變效應很相近。(4) 由應變能密度所得到之熱機械效應與上述之剪應變範圍的趨勢是一致的。(5) 對於95.5Sn-3.9Ag-0.6Cu所受之包辛格效應最為明顯，而95.5Sn-3.8Ag-0.7Cu次之，之後為96.5Sn-3.5Ag，63Sn-37Pb是最不明顯的。

The removal of lead (Pb) from electronic products necessitates the replacement of the classical eutectic Sn-Pb solder by an adequate material. Among alternative lead-free solders the Sn-Ag/Sn-Ag-Cu materials seem to have the most promise as lead-free solders in the IC industry. The plastic-creep analyses of solder-bumped IC on substrate or printed circuit board (PCB) assemblies subjected to the different temperature cyclic loadings are presented. For example, the melting point of Sn-Ag/Sn-Ag-Cu solders is higher than that of Sn-Pb solders by 30℃ in particular. These in turn lead to significant divergences in plastic and creep behaviors.
This research uses the validated finite-element analyses to study the elastic-plastic-creep behaviors of the 96.5Sn-3.5Ag, 95.5Sn-3.8Ag-0.7Cu and 95.5Sn-3.9Ag-0.6Cu lead-free solders and the classical 63Sn-37Pb solder bumped wafer level chip scale package on PCB assemblies subjected to two different temperature cyclic loadings. The behaviors of shear stress-strain hysteresis loops and strain energy density are examined on the key upper-right spot at the outmost corner solder joint. It can be seen that, (1) the effect of the elastic strain is slight on the thermo-mechanical behavior of these four solder alloys; (2) the shear strain range of the 96.5Sn-3.5Ag solder alloy derive almost from the plastic strain, that is, it can sustain more creep than others; (3) the plastic or creep strain effect of the 95.5Sn-3.8Ag-0.7Cu solder alloy is close to the 63Sn-37Pb solder respectively; (4) the effect of the strain energy density on these solder alloys is consistent with that of the shear strain range; (5) the 95.5Sn-3.9Ag-0.6Cu solder alloy is the most significant on the Bauschinger effect among the four solder alloys and the secondary is the 95.5Sn-3.8Ag-0.7Cu solder, then is the 96.5Sn-3.5Ag. Besides, the 63Sn-37Pb solder is not noticeable.

摘要 i
Abstract ii
誌謝 iii
目錄 iv
表目錄 vi
圖目錄 vii
第一章 緒論 1
1-1 前言 1
1-2 晶圓級封裝 2
1-3 鉛的危害與無鉛的未來 3
1-4 研究目的與方法 5
1-5 文獻回顧 6
1-6 本文架構 8
第二章 理論基礎與文獻驗證 9
2-1 簡介 9
2-2 材料性質 9
2-2-1 彈性與塑性[9] 10
2-2-2 降伏準則 11
2-2-3 隨動硬化法則 12
2-2-4 包辛格效應 13
2-2-5 潛變 14
2-2-6 溫度循環負載 15
2-3 文獻驗證 16
2-3-1 CAE分析基本假設 17
2-3-2 材料參數 17
2-3-3 封裝體結構與尺寸 19
2-3-4 負載及邊界條件 21
2-3-5 驗證 23
第三章 3-D模型推延與模擬分析 25
3-1 材料參數與溫度循環負載 25
3-2 模擬分析 26
3-2-1 有/無彈性應變效應之錫球材料的熱機械行為 26
3-2-2 有/無塑性應變效應之錫球材料的熱機械行為 31
3-2-3 有/無潛應變效應之錫球材料的熱機械行為 36
3-2-4 彈、塑性與潛應變效應在不同之FEA的比較 41
3-2-5 錫球材料與溫度範圍對熱機械行為的比較 55
第四章 結果分析與討論 62
第五章 結論與未來展望 64
5-1 結論 64
5-2 未來展望 64

[1] J. H. Lau, S. H.. Pan, and C. Chang, Creep Analysis of
Wafer Level Chip Scale Package(WLCSP) With 96.5Sn-3.5Ag and
100In Lead-Free Solder Joints and Microvia Build-Up Printed
Circuit Board, Transactions of the ASME, Journal of
Electronic Packaging, 2002, 124：69-76.
[2] J. H. Lau, S. W. R. Lee,and C. Chang, Solder Joint
Reliability of Wafer Level Chip Scale Packages(WLCSP):A
Time-Temperature-Dependent Creep Analysis, Transactions of
the ASME, Journal of Electronic Packaging, 2000, 122：311-
316.
[3] J. H. Lau, S. W. R. Lee, Effect of Build-Up Printed Circuit
Board Thickness on the Solder Joint Reliabikity of a Wafer
Level Chip Scale Package(WLCSP), IEEE Transactions on
Electronics Packaging Manufacturing, 2002, 25(1)：3-13.
[4] J. H. Lau, Critical Issues of Wafer Level Chip Scale Package
(WLCSP) With Emphasis on Cost Analysis and Solder Joint
Reliability, IEEE Transactions on Electronics Packaging
Manufacturing, 2002, 25(1)：42-50.
[5] J. H. Lau, S. W. R. Lee, Modeling and Analysis of 96.5Sn-
3.5Ag Lead-Free Solder Joints of Wafer Level Chip Scale
Package on Buildup Microvia Printed Circuit Board, IEEE
Transactions on Electronics Packaging Manufacturing, 2002,
25(1)：51-54.
[6] J. H. Lau, S. H. Pan,and C. Chang, A New Thermal-Fatigue
Life Prediction Model for Wafer Level Chip Scale Package
(WLCSP) Solder Joint, Transactions of the ASME, Journal of
Electronic Packaging, 2002, 124：212-220.
[7] John H. L. Pang, C. W. Seetoh, Z. P. Wang, CBGA Solder
Joint Reliability Evaluation Based on Elastic-Plastic-Creep
Analysis, Transactions of the ASME, Journal of Electronic
Packaging, 2000, 122：255-261.
[8] John H. L. Pang, D. Y. R. Chong, Flip Chip on Board Solder
Joint Reliability Analysis Using 2-D and 3-D FEA Models,
IEEE Transactions on Advanced Packaging, 2001, 24(4)：499-
506.
[9] W. F. Smith, Foundations of Materials Science and
Engineering, 3e, Mc Graw Hill, 2005.
[10] R. Dudek, H. Walter, Ralf Doering, and B. Michel, Thermal
Fatigue Modelling for SnAgCu and SnPb Solder Joints, IEEE,
5th Int. Conf. on Thermal and Mechanical Simulation and
Experiments in Micro-electronics and Micro-Systems,
EuroSimE, 2004, pp.557-564.
[11] J. H. Lau, HDPUG`s Design for Lead-Free Solder Joint
Reliability of High-Density Packages, IPC SMEMA Council
APEX, 2003, 42(2)：1-13
[12] 鐘文仁, 陳佑任, IC封裝製程與CAE運用, 全華科技圖書股份有限公
司, 2003.
[13] J. H. L. Pang, B.S. Xiong, and F. X. Che, “Modeling
Stress Strain Curves for Lead-Free 96.5Sn-3.8Ag-0.7Cu
Solder”, Int. Conf. on Thermal and Mechanical Simulation
and Experiments in Micro-electronics and Micro-Systems,
2004, pp.449-453.
[14] C. Thanachayanont and N. Ramungul, “Low-Cost Lead-Free
Solder for EE Industries,” IEEE ICIT’02, Bangkok,
THAILAND, 2002, pp.1213-1218.
[15] B. Z. Hong, ”Thermal Fatigue Analysis of a CBGA Package
with Lead-Free Solder Fillets”, IEEE, InterSoci. Conf. on
Thermal Phenomena, 1998, pp.205-211.
[16] R. K. Roy, A primer on the Taguchi Method, New York, Van
Nostrand Reinhold, 1990.
[17] ANSYS, “Nonlinear Structural Analysis,” ANSYS Users’
Manual 10.0, 2005.