Browse > Article
http://dx.doi.org/10.5916/jkosme.2013.37.4.351

Visualization for racing effect and meniscus merging in underfill process  

Kim, Young Bae (서울과학기술대학교 에너지환경대학원)
Kim, Sungu (서울과학기술대학교 대학원)
Sung, Jaeyong (서울과학기술대학교 기계자동차공학과)
Lee, MyeongHo (서울과학기술대학교 기계자동차공학과)
Publication Information
Journal of Advanced Marine Engineering and Technology / v.37, no.4, 2013 , pp. 351-357 More about this Journal
Abstract
In flip chip packaging, underfill process is used to fill epoxy bonder into the gap between a chip and a substrate in order to improve the reliability of electronic devices. Underfill process by capillary motion can give rise to unwanted air void formations since the arrangement of solder bumps affects the interfacial dynamics of flow meniscus. In this paper, the unsteady flows in the capillary underfill process are visualized and then the racing effect and merging of the meniscus are investigated according to the arrangement of solder bumps. The result is shown that at higher bump density, the fluid flow perpendicular to the main direction of flow becomes stronger so that more air voids are formed. This phenomenon is more conspicuous at a staggered bump array than at a rectangular bump array.
Keywords
Flip-chip; Capillary; Underfill process; Racing effect; Meniscus merging;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 J. W. Wan, W. J. Zhang, and D. J. Bergstrom, "Numerical modeling for the underfill flow in flip-chip packaging", IEEE Transactions on Components and Packaging Technologies, vol. 32, no. 2, pp. 227-233, 2009.   DOI   ScienceOn
2 K-D. Ro, J-T. Park, and Y-S. B, "The visualization of the flow field through tube banks with in-line and staggered arrangements using the PIV", Journal of the Korean Society of Marine Engineering, vol. 33, no. 1, pp. 44-51, 2009 (in Korean).   DOI   ScienceOn
3 L. Nguyen, C. Quentin, P. Fine, B. Cobb, S. Bayyuk, H. Yang, and S. A. Bidstrup-Allen, "Underfill of flip chip on laminates: simulation and validation", IEEE Transactions on Components and Packaging Technology, vol. 22, no. 2, pp. 168-176, 1999.   DOI   ScienceOn
4 R. R. Tummala, Fundamentals of Microsystems Packaging, McGrew-Hill, 2001.
5 Y. B. Kim, and J. Sung, "Capillary-driven micro flows for underfill process in microelectronics package", Journal of Mechanical Science and Technology, vol. 26, no. 12, pp. 3751-3759, 2012.   DOI   ScienceOn
6 J. W. Wan, W. J. Zhang, and D. J. Bergstrom, "Experimental verification of models for underfill flow driven by capillary forces in flip-chip packaging", Microelectronics Reliability, vol. 48, no. 3, pp. 425-430, 2008.   DOI   ScienceOn
7 D. Suryanarayana, R. Hsiao, T. P. Gall, and J. M. McCreary, "Enhancement of flip-chip fatigue life by encapsulation", IEEE Transactions on Components, Hybrids, and Manufacturing Technology, vol. 14, no. 1, pp. 218-223, 1991.   DOI   ScienceOn
8 M. H. Gordon, G. Ni, W. F. Schmidt, and R. P. Selvam, "A capillary-driven underfill encapsulation process", Advanced Packaging, vol. 8, no. 4, pp. 34-37, 1999.
9 T. Hashimoto, T. Shin-ichiro, K. Morinishi, and N. Satofuka, "Numerical simulation of conventional capillary flow and no-flow underfill in flip-chip packaging", Computers and Fluids, vol. 37, no. 5, pp. 520-523, 2008.   DOI   ScienceOn