Title :
Crystallization of electroless Ni-P under bump metallization induced by solder reaction
Author :
Jang, J.W. ; Kim, P.G. ; Tu, K.N. ; Frear, D.R.
Author_Institution :
Dept. of Mater. Sci. & Eng., California Univ., Los Angeles, CA, USA
Abstract :
Solder reaction-assisted crystallization of electroless Ni-P under bump metallization in the Si/SiO2/Al/Ni-P/63Sn-37Pb multilayer structure was analyzed using transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray, and electron probe microanalysis. The electroless Ni-P had an amorphous structure and a composition of Ni85P15 in the as-plated condition. Upon reflow, the electroless Ni-P transformed to Ni 3Sn4 and Ni3P. The crystallization of electroless Ni-P to Ni3P was induced by Ni depletion from electroless Ni-P to form Ni3Sn4. The crystallization kinetics were found to be diffusion-controlled
Keywords :
X-ray chemical analysis; crystallisation; diffusion; electroless deposited coatings; flip-chip devices; integrated circuit interconnections; integrated circuit metallisation; integrated circuit packaging; microassembling; nickel alloys; phosphorus alloys; reaction kinetics; reflow soldering; scanning electron microscopy; surface chemistry; surface structure; transmission electron microscopy; Ni depletion; Ni3P; Ni3P phase; Ni3Sn4; Ni3Sn4 formation; Ni3Sn4 phase; Ni85P15; Ni85P15 as-plated composition; Si/SiO2/Al/Ni-P/SnPb multilayer structure; SnPb-NiP-Al-SiO2-Si; crystallization; crystallization kinetics; diffusion-controlled crystallization kinetics; electroless Ni-P amorphous structure; electroless Ni-P transformation; electroless Ni-P under bump metallization; electron probe microanalysis; energy dispersive X-ray; flip chip packaging; reflow; scanning electron microscopy; solder reaction; solder reaction-assisted crystallization; transmission electron microscopy; Amorphous materials; Crystallization; Dispersion; Kinetic theory; Metallization; Nonhomogeneous media; Probes; Scanning electron microscopy; Tin; Transmission electron microscopy;
Conference_Titel :
Advanced Packaging Materials: Processes, Properties and Interfaces, 1999. Proceedings. International Symposium on
Conference_Location :
Braselton, GA
Print_ISBN :
0-930815-56-4
DOI :
10.1109/ISAPM.1999.757322
