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http://dx.doi.org/10.5781/KWJS.2008.26.3.030

A Study on the Optimization of IR Laser Flip-chip Bonding Process Using Taguchi Methods  

Song, Chun-Sam (Seoul Technopark)
Ji, Hyun-Sik (Graduate School of NID Fusion Technology, Seoul National University of Technology)
Kim, Joo-Han (Department of Mechanical Engineering, Seoul National University of Technology)
Kim, Jong-Hyeong (Department of Mechanical Design and Automation Engineering, Seoul National University of Technology)
Ahn, Hyo-Sok (Graduate School of NID Fusion Technology, Seoul National University of Technology)
Publication Information
Journal of Welding and Joining / v.26, no.3, 2008 , pp. 30-36 More about this Journal
Abstract
A flip-chip bonding system using IR laser with a wavelength of 1064 nm was developed and associated process parameters were analyzed using Taguchi methods. An infrared laser beam is designed to transmit through a silicon chip and used for transferring laser energy directly to micro-bumps. This process has several advantages: minimized heat affect zone, fast bonding and good reliability in the microchip bonding interface. Approximately 50 % of the irradiated energy can be directly used for bonding the solder bumps with a few seconds of bonding time. A flip-chip with 120 solder bumps was used for this experiment and the composition of the solder bump was Sn3.0Ag0.5Cu. The main processing parameters for IR laser flip-chip bonding were laser power, scanning speed, a spot size and UBM thickness. Taguchi methods were applied for optimizing these four main processing parameters. The optimized bump shape and its shear force were modeled and the experimental results were compared with them. The analysis results indicate that the bump shape and its shear force are dominantly influenced by laser power and scanning speed over a laser spot size. In addition, various effects of processing parameters for IR laser flip-chip bonding are presented and discussed.
Keywords
Soldering; Flip-chip; Laser; Micro-bump;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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1 Y. E. Shin, Y.W. Koh and J.M. Kim : Trend of electronic packaging and charateristics evaluation by shape of solder joints, Journal of KWS, 20-3 (2002), 24-30   과학기술학회마을
2 M. Y. Li, C. Q. Wang, H. S. Bang and Y. P. Kim: Development of a Flux-less Soldering Method by Ultrasonic Modulated Laser, Journal of Materials Processing Technology, 168-2 (2005), 303-307   DOI   ScienceOn
3 R. K. Ulrich, and W. D. Brown: Advanced Electronic Packaging, Wiley-Interscience, 2006, 417-418
4 H. Schafer, P. Yuan and Z. P. Wang: Investigation of Ultrasonic Filp Chip Bonding on Flex Substartes, Electronic Packaging Technology Proceeding, (2003), 117-120
5 S. Theppakuttai, D. B. Shao and S. C. Chen: Localized Laser Transmission Bonding for Microsystem Fabrication and Packaging, Journal of Manufacturing Process, 6-1 (2004), 1-8   DOI   ScienceOn
6 R. R. Tummala: Fundamentals of Microsystems Packaging, McGraw Hill, 2001, 281-284
7 J. W. Kim, D. G. Kim, S. S. Ha, W. C. Moon, C. S. Yoo, J. H. Moon and S. B. Jung: Evaluation of Thermo-mechanical Reliability of Flip Chip Solder Joints(I):I Pb-bearing Solder, The Korean Institute of Metals and Materials, 44-8 (2006), 581-586   과학기술학회마을
8 S. W. Kim, S. H. Kim and B. H. Youn: Bonding Properties of BGA Solder Ball with Laser Process, KWS, 45-Autumn (2005)
9 K. N. Chiang and C.A. Yuan : An overview of solder bump shape prediction algorithms with validations, IEEE transactions on advanced packaging, 24-2 (2001), 158-162   DOI   ScienceOn
10 JSA : JIS Z 3198 Test methods for lead free solders, 2003
11 J. W. Kim, D.G. Kim and S.B. Jung : Investigation of the test parameters and bump structures in the shear test of flip chip solder bump, Thin solid films, 504-1-2 (2006), 405-409   DOI   ScienceOn
12 T. Teutsch, E. Zakel and G. Azdasht: advanced packaging, PennWell, 2006, 420-450
13 J. F. Ready, D. F. Farson and T. Feeley: Handbook of Laser Materials Processing, Laser Institute of America, 2001, 138