The grain size effect on phase growth rate in the Cu-Sn system

Є. В. Татарчук, І. Г. Галат

Abstract


The current trends of development of microelectronics require reduction of the sizes of chips and density increasing. In turn, it requires high-quality approaches to production of electronic devices. One of reasons of destruction of tracks of printed circuit boards of chips is formation of pores, their growth and transformation into microcracks.


Physical process which forms of voids in Cu-Sn system was investigated and presented in papers [5,6,7]. In case of heating up of solder joints on Cu-Sn boundary as a result of reactionary diffusion the phase Cu6Sn5 and phase Cu3Sn are formed. Through a certain period the phase Cu3Sn "eats" the phase Cu6Sn5 and thus on interphases there voidis formed. Formation of pores is caused by Kirkendall effect.


Further pores integrate and turn into microcracks that leads to distraction of soldering joints. Experimental investigations showed that similar process occurs in Cu-Sn system where the plate of copper is covered with a tin film. Tin was applied on copper plates with different grains by the galvanic method.


It has been stated by Haila that increasing size of copper grains influences of deceleration of rate of pores formation. The present paper is devoted to this subject. In the work it has been investigated dependence between rate of phase Cu6Sn5+Cu3Sn growth and size of cooper graines.


Experiment was made at two different temperatures 250 0C and 270 0C It has been stated that the increasing of grains sizes on plates of copper reduces the growth rate of the phases Cu6Sn5+Cu3Sn. The results received in the present paper confirm the Haila`s investigations, because under condition of slow diffusion the growth of pores is respectively decelerated.


Keywords


reaction diffusion; binary system; electromigration; growth kinetics; grain boundaries; crystallization

References


1. K. N. Tu (2003). Recent advances on electromigration in very-large-scale-integration of interconnects. Journal of Applied Physics. (94). 5451–5473.

2. K. N. Tu, H. Gan (2005). Polarity effect of electromigration on kinetics of intermetallic compound formation in Pb-free solder V-groove samples. Journalof Applied Physics. (97). 063514.

3. T. Y. Lee, K. N. Tu, D. R. Frear (2001). Electromigration of eutectic SnPb and SnAg3.8Cu0.7 flip chip solder bumps and underbump metallization. Journal of Applied Physics. (90). 4502–4508.

4. D. O. Zraev, S. V. Kornienko. (2014). Investigation of the growth kinetics of the intermetallic compoundin the system copper-tin with electromigration. Visnyk Cherkaskogo universiteta. 309. (16). 64-69.

5. K. P. Gurov, A. M. Gusak (1981). On the theory of phase growth in the diffusion zone during mutual diffusion in an external electric field. Phys Met Metallogr. (52), 75–81.

6. N. A. Krasnoshlyk, A. O. Bogatyryov (2012). Numeric study of the diffusional phase competention based on steady-state model.Vesnik nacionalnogo tehnicheskogo universiteta. Harkovskiy politehnicheskiy institute. 968. (62). 113-119.

7. I. V. Sobchenko. (2007) Kinetic Monte Carlo model of the nanovoid motion. Visnyk Cherkaskogo universiteta. (114). 56-65.

8. Yu Chun, Yang Yang, Jieshi Chen, Jijin Xu, Junmei Chen, Hao Lu. (2014). Effect of deposit thickness during electroplating on Kirkendall voiding at Sn/Cu joints. Marerials Letters. (128). 9-11.

9. Iuliana Panchenko, Kristof Croes, I. De Wolf, J. De Messemaeker, Eric Beyne, Klaus-Juergen Wolter. (2014). Degradation of Cu6Sn5 intermetallic compound by pore formation in solid–liquid interdiffusion Cu/Sn microbump interconnects. Marerials Letters.(128). 9-11.

10. Hailong Li, Rong An, Chunqing Wang, Yanhong Tian, Zhi Jiang. (2015). Effect of Cu grain size on the voiding propensity at the interface of SnAgCu/Cu solder joints. Marerials Letters. (144). 97-99. 


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