銅線應用於打線接合上相較於金線有成本低、強度高、導電性及導熱性佳等優勢，但氧化問題及延展性的不足使得銅線於銲線製程上的可靠度下降。而深抽後之銅線經不同溫度線上熱處理過程，欲了解在如此高的熱處理溫度及快速的加熱時間下，對線材組織的分佈情形及影響之後之結球特性，因此本研究針對ψ=25μm之純銅線，以改變線材之熱處理溫度﹙300℃～550℃，加熱時間約為0.4sec﹚，來探討線上熱處理之銅線經放電結球前後之微觀組織與機械性質變化，並以二者之抗拉強度進行可靠度分析。
實驗結果顯示，線材隨著熱處理溫度的提高，微硬度值及拉伸強度下降且延性上升，在溫度450℃以上可達到完全再結晶進而晶粒成長；由線材微硬度值顯示出變動範圍大，意味著再結晶後之組織分佈不均勻，但由拉伸數據顯示出數據集中度較高，巨觀而言對拉伸性質影響較小。
各條件之線材經EFO放電結球過程後，其結球端為柱狀晶組織，在頸部熱影響區之晶粒因受熱影響而產生再結晶及組織粗大的現象。根據文獻上指出及由本研究之微硬度值、拉伸測試顯示熱影響區強度較弱，由結球微硬度值顯示熱影響區微硬度值偏低的範圍距離球端約為200μm；由拉伸破斷外觀型態顯示出斷裂位置發生於距離球端約為50μm～200μm之間，亦為微硬度值偏低的範圍之內。
韋伯分析結果顯示，在線材方面皆有不錯的可靠度，而結球抗拉強度之可靠度雖然較線材低，但皆屬於m＞4之磨耗破壞型且為右偏型，其中又以溫度450℃熱處理條件之線材表現最佳。

The advantages of copper wire for wire bonding are lower cost﹐higher strength﹐higher electrical and thermal conductivity in comparison with gold wire. Oxidation and insufficient ductility of copper wire result in lowering reliability in the wire bonding process. In order to realize the microstructure and FAB characteristic of the drawn copper wire after the continuous heat treatment process﹐in this study﹐copper wire ﹙ψ=25μm﹚of different heat treatment processes ﹙300℃～550℃﹐heating time about 0.4sec﹚ were discussed the effects of EFO ﹙Electric Flame Off﹚ process on microstructure and mechanical properties. Then the UTS data of the copper wire and FAB were discussed by Weibull′s reliability analysis.
The experiments showed the higher heat treatment temperature﹐the lower microhardness﹙Hv﹚﹐tensile strength and higher elongation of the wire. The wire could be obtained fully recrystallized and grain growth above 450℃ of heat treatment temperature. From the results of microhardness and tensile test﹐the former data fluctuation was larger than the latter data fluctuation. It could be seen that the distribution of microstructure was non-uniform after recrystalliztion.
The wire tip was melted by EFO process to form a spherical ball which displayed column-like grain growth. And the wire near the ball﹐the heat affect zone ﹙HAZ﹚﹐showed coarse grain by recrystalliztion and grain growth. According to the literature and this study﹐the HAZ had weaker strength and the weakest hardness in the HAZ was about no more than 200μm away from the ball and the distance was same as the fracture position of tensile test.
From the Weibull analysis﹐the Weibull modulus under all condition of wire and FAB tensile test were greater than 4 and they were wear-out failure mode. Though the Weibull modulus of FAB were lower than that of wire under the same condition. And 450℃ was the best condition of continuous heat treatment.

1﹒F. Wulff, C. D. Breach and K. Dittmer, “Crystallographic Texture of
Drawn Gold Bonding Wires Using Electron Backscattered Diffraction
(EBSD)”, J. Mater. Sci. Lett., 22(2003), pp. 1373-1376.
2﹒H. M. Ho, W. Lam, S. Stoukatch, P. Ratchev, Charles J. Vath III and
E.Beyne, “Direct Gold and Copper Wires Bonding on Copper”,
Microelectron. Reliab., 43(2003), pp. 912-923.
3﹒N. Srikanth, S. Murali, Y.M. Wong and Charles J. Vath III, “Critical
Study of Thermosonic Copper Ball Bonding”, Thin Solid Films,
462-463(2004), pp. 339-345.
4﹒S. Murali, N. Srikanth and Charles J. Vath III, “Grains, Defrmation
Substructures, and Slip Bands Observed in Thermosonic Copper Ball
Bonding”, Mater. Charact., 50(2003), pp. 39-50.
5﹒G. Harman, Wire Bonding in Microelectronics Materials, Processes,
Reliability, and Yield, 2nd ed., McGraw-Hill, New York, 1997,
pp.1-11.
6﹒陳昭亮，張昫揚，「密集角距封裝之金線結球參數分析研究」，興
大工程學刊，第十二卷，第二期(民國九十年)，127-141頁。
7﹒陳家旭，「打線接合之實驗與有限元素研究」，國立交通大學機
械工程研究所碩士論文，民國九十一年。
8﹒http://pilot.mse.nthu.edu.tw/micro/chap9/ch9-3.htm
9﹒Properties and Selection: Nonferrous Alloys and Pure Metals, Metals
Handbook, Ninth Edtion, Volume 2.
10. http://www.knstaiwan.com/prodserv/copper/index.asp
11. S. Murali, N. Srikanth and Charles J. Vath III, “An Analysis of
Intermetallics Formation of Gold and Copper Ball Bonding on
Thermal Aging”, Mater. Res. Bull., 38(2003), pp. 637-646.

12. S. Mural, N. Srikanth, Charles J. Vath III, “Effect of Wire Size on The
Formation of Intermetallics and Kirkendall Voids on Thermal Againg
of Thermosonic Wire Bonds”, Mater. Lett., 58(2004), pp. 3096-3101.
13. J. Beleron, A. Turiano, Dodgie R. M. Calpito, D. Stephan, Saraswati,
F. Wulff, C Breach, “Tail Pull Strength of Cu Wire on Gold and
Silver-plated Bonding Leads”, Mater. and Appli. Cent., Kulicke &
Soffa﹙S.E.A﹚Pte. Ltd.,2005.
14. Practical Reliability Engineering, P. D. T. O’Connor, John Wiley &
Sons, 3rd Edition, 1991, Chap. 1-6.
15. Reliability in Engineering Design, K. C. Sons, John Wiley & Sons,
1977, Chap. 1-6.
16. Mechanical Reliability, A. D. S. Carter, John Wiley & Sons, 2nd
Edition, 1986, Chap. 2 and 11.
17. B. Faucher and W. R. Tyson, “On the Determination of Weibull
Parameters”, J. Mater. Sci. Lett., vol.7(1988), pp. 1199-1203.
18. Reliability Analysis in Engineering Applications, S. H. Dai, and M.
O. Wang, Van Nostrand Reinhold, 1992, pp. 353-358
19. 信賴性管理便覽編輯委員會編，「品質保證之信賴性管理便覽」，
日本規格協會出版，1985，45-51頁（日文）。
20. X. D. Li. and L. Edwards, “Theoretical Modeling of Fatigue
Threshold for Aluminum Alloys”, Eng. Fract. Mech., 20(1996), pp.
35-48.
21. 真壁肇編，陳耀茂譯，「可靠性工程入門」，中華民國品質管制
學會，1989，第8 章。
22. 信賴性研究委員會編，可靠度研究小組譯，「實用可靠度」，先鋒
企業管理發展中心，1984。
23. 王元亭，「放電結球細微銅導線抗拉強度之韋伯解析研究」，國
立成功大學材料科學與工程研究所碩士論文，民國94年。