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Research Papers

Variable-Length Link-Spring Model for Kink Formation During Wire Bonding

[+] Author and Article Information
Fuliang Wang

e-mail: wangfuliang@csu.edu.cn

Lei Han

State Key Laboratory of High Performance
Complex Manufacturing,
Changsha 410083, China;
School of Mechanical and Electrical Engineering,
Central South University,
Changsha 410083, China

Contributed by the Electronic and Photonic Packaging Division of ASME for publication in the JOURNAL OF ELECTRONIC PACKAGING. Manuscript received June 5, 2012; final manuscript received July 13, 2013; published online September 19, 2013. Assoc. Editor: Kaustubh Nagarkar.

J. Electron. Packag 135(4), 041004 (Sep 19, 2013) (6 pages) Paper No: EP-12-1061; doi: 10.1115/1.4025308 History: Received June 05, 2012; Revised July 13, 2013

Kinks have a strong influence on the structural performance of wire bonds. In this study, a variable-length link-spring model has been developed to better understand kink formation. In this model, a gold wire was decomposed into segments that were represented by a link and a torsional spring. One end of the gold wire was fixed, and the other end was free. The friction and air tension forces at the wire ends were considered a function of the capillary position, and the wire segments and moment balance equations were added at the free end as the wire length increased. By using this model, the wire profile, moment, and curvature diagrams at the reverse motion stage were obtained to study the dynamical kink formation and wire-length increasing processes. The analysis result was verified experimentally. Good agreement is obtained between the analytical and the experimental wire profiles. This study indicates that a moment magnitude of several hundred mN·μm is required to form a kink, and the wire profile is the result of the residual curvature and the instantaneous bending moment.

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Copyright © 2013 by ASME
Topics: Wire , Springs , Deformation
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References

Kung, H. K., Sun, Y. P., Lee, J. N., and Chen, H. S., 2008, “A Method to Determine the Sweep Resistance of Wire Bonds for Microelectronic Packaging,” Microelectron. Eng., 85(9), pp. 1902–1909. [CrossRef]
Shu, B., 1992, “Wire Bond Development for High-Pincount Surface-Mount,” Proceedings 42nd Electronic Components and Technology Conference ('92 ECTC), San Diego, May 18–20, pp. 890–898. [CrossRef]
Groover, R., Shu, W. K., and Lee, S. S., 1994, “Wire Bond Loop Profile Development for Fine Pitch-Long Wire Assembly,” IEEE Trans. Semicond. Manuf., 7(3), pp. 393–399. [CrossRef]
Seuntjens., J., Lu, Z. P., Emily, R., Tok, C. W., Wulff, F., and San Sanda Aung, A. S. K., 1999, “Development of New Ultra-High Stiffness Gold Bonding Wire,” available at: www.utilisegold.com/assets/file/rs_archive/AW99_paper.PDF
Saraswati, E., Phyu, T., D.Stephan, F. W.Wulff, and C. D.Breach, A. D. R. M. C., 2004, “Looping Behaviour of Gold Ballbonding Wire,” Proceedings of 6th Electronics Packaging Technology Conference (EPTC 2004), Singapore, December 8–10, pp. 723–728. [CrossRef]
Ohno, Y., Ohzeki, Y., Aso, T., and Kitamura, O., 1992, “Factors Governing the Loop Profile in Au Bonding Wire,” Proceedings 42nd Electronic Components and Technology Conference ('92 ECTC), San Diego, CA, May 18–20, pp. 899–902. [CrossRef]
Tay, A. A. O., Seah, B. C., and Ong, S. H., 1997, “Finite Element Simulation of Wire Looping During Wirebonding,” 1997 Proceedings of the Pacific Rim/ASME International Intersociety Electronic and Photonic Packaging Conference (InterPack'97), Kohala Coast, HI, June 15–19, Vol. 1, pp. 399–406.
Ng, B. H., Tay, A. A. O., and Ong, S. H., 2002, “Three Dimensional Finite Element Simulation of Wire Looping Process in Wirebonding,” Proceedings 4th Electronics Packaging Technology Conference (EPTC 2002), Singapore, December 10–12, pp. 334–337. [CrossRef]
Liu, D. S., and Chao, Y. C., 2003, “Effects of Dopant, Temperature, and Strain Rate on the Mechanical Properties of Micrometer Gold-Bonding Wire,” J. Electron. Mater., 32(3), pp. 159–165. [CrossRef]
Liu, D. S., Chao, Y. C., and Wang, C. H., 2004, “Study of Wire Bonding Looping Formation in the Electronic Packaging Process Using the Three-Dimensional Finite Element Method,” Finite Elem. Anal. Design, 40(3), pp. 263–286. [CrossRef]
Lo, Y. L., Ho, T. L., Chen, J. L., Lee, R. S., and Chen, T. C., 2001, “Linkage-Spring Model in Analyzing Wirebonding Loops,” IEEE Trans. Compon. Packag. Technol., 24(3), pp. 450–456. [CrossRef]
Lo, Y. L., Chen, T. C., and Ho, T. L., 2001, “Design in Triangle-Profiles and T-Profiles of a Wirebond Using a Linkage-Spring Model,” IEEE Trans. Compon. Packag. Technol., 24(3), pp. 457–467. [CrossRef]
Lo, Y. L., and Tsao, C. C., 2002, “Wirebond Profiles Characterized by a Modified Linkage-Spring Model Which Includes a Looping Speed Factor,” Microelectron. Reliab., 42(2), pp. 285–291. [CrossRef]
Wang, F., Chen, Y., and Han, L., 2012, “Experiment Study of Dynamic Looping Process for Thermosonic Wire Bonding,” Microelectron. Reliab., 52(6), pp. 1105–1111. [CrossRef]
Chucheepsakul, S., Buncharoen, S., and Huang, T., 1995, “Elastica of Simple Variable-Arc-Length Beam Subjected to End Moment,” J. Eng. Mech., 121(7), pp. 767–772. [CrossRef]
Athisakul, C., and Chucheepsakul, S., 2008, “Effect of Inclination on Bending of Variable-Arc-Length Beams Subjected to Uniform Self-Weight,” Eng. Struct., 30(4), pp. 902–908. [CrossRef]
Plaut, R. H., Dillard, D. A., and Borum, A. D., 2011, “Collapse of Heavy Cantilevered Elastica With Frictional Internal Support,” ASME J. Appl. Mech., 78(4), p. 041011. [CrossRef]
Humer, A., and Irschik, H., 2011, “Large Deformation and Stability of an Extensible Elastica With an Unknown Length,” Int. J. Solids Struct., 48(9), pp. 1301–1310. [CrossRef]
Humer, A., 2011, “Elliptic Integral Solution of the Extensible Elastica With a Variable Length Under a Concentrated Force,” Acta Mech., 222(3–4), pp. 209–233. [CrossRef]
Pulngern, T., Halling, M. W., and Chucheepsakul, S., 2005, “Large Deflections of Variable-Arc-Length Beams Under Uniform Self Weight: Analytical and Experimental,” Struct. Eng. Mech., 19, pp. 413–423. [CrossRef]
F.L.Wang, Y., C., and Lei, H., 2012, “Experiment Study of Dynamic Looping Process for Thermosonic Wire Bonding,” Microelectron. Reliab., 52, pp. 1105–1111. [CrossRef]
Tay, A. A. O., Yeo, K. S., Wu, J. H., and Lim, T. B., 1995, “Wirebond Deformation During Molding of IC Packages,” ASME J. Electron. Packag., 117(1), pp. 14–19. [CrossRef]

Figures

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Fig. 1

Wire-length increase and kink formation processes

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Fig. 2

Schematic of variable-length link-spring model

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Fig. 3

Relation between M and Δθ [11]

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Fig. 4

Wire profiles at different capillary positions

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Fig. 5

Images at four positions from the experiment

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Fig. 6

Comparison of loop profiles between the experimental and the analysis results

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Fig. 7

Moment and curvature distribution along the wire (−55 μm RM)

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Fig. 8

Moment and curvature distribution along the wire (−155 μm RM)

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Fig. 9

Moment and curvature distribution along the wire (−411.6 μm RM)

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