Under bump metallurgy study for Pb-free bumping

被引:11
作者
Jang, SY
Wolf, J
Paik, KW
机构
[1] Korea Adv Inst Sci & Technol, KAIST, Dept Mat Sci & Engn, Taejon, South Korea
[2] Fraunhofer IZM, D-13355 Berlin, Germany
关键词
under bump metallurgy (UBM); flip-chip; electroplating; Pb free; Sn/3.5Ag; Pb/63Sn; intermetallic compounds (IMC);
D O I
10.1007/s11664-002-0103-x
中图分类号
TM [电工技术]; TN [电子技术、通信技术];
学科分类号
0808 ; 0809 ;
摘要
The demand for Pb-free and high-density interconnection technology is rapidly growing. The electroplating-bumping method is a good approach to meet fine-pitch requirements, especially for high-volume production, because the volume change of patterned-solder bumps during reflow is not so large compared with the stencil-printing method. This paper proposes a Sn/3.5Ag Pb-free electroplating-bumping process for high-density Pb-free interconnects. It was found that a plated Sn/Ag bump becomes Sn/Ag/Cu by reflowing when Cu containing under bump metallurgy (UBM) is used. Another important issue for future flip-chip interconnects is to optimize the UBM system for high-density and Pb-free solder bumps. In this work, four UBM systems, sputtered TiW 0.2 mum/Cu 0.3 mum/electroplated Cu 5 mum, sputtered Cr 0.15 mum/Cr-Cu 0.3 mum/Cu 0.8 mum, sputtered NiV 0.2 mum/Cu 0.8 mum, and sputtered TiW 0.2 mum/NiV 0.8 mum, were investigated for interfacial reaction with electroplated Pb/63Sn and Sn/3.5Ag solder bumps. Both Cu-Sn and Ni-Sn intermetallic compound (IMC) growth were observed to spall-off from the UBM/solder interface when the solder-wettable layer is consumed during a liquid-state "reflow" process. This IMC-spalling mechanism differed depending on the barrier layer material.
引用
收藏
页码:478 / 487
页数:10
相关论文
共 48 条
[1]  
BADER S, 1995, ACTA METALL MATER, V43, P329, DOI 10.1016/0956-7151(94)00224-6
[2]   STUDIES OF SLT CHIP TERMINAL METALLURGY [J].
BERRY, BS ;
AMES, I .
IBM JOURNAL OF RESEARCH AND DEVELOPMENT, 1969, 13 (03) :286-&
[3]   STRESSES IN MULTILAYER COMBINATIONS OF SPUTTER DEPOSITED COATINGS OF NI, TI, TIC+NI, AND TIB2+NI ON CARBON-STEEL SUBSTRATES [J].
CHAMBERS, DL ;
TAYLOR, KA ;
WAN, CT ;
SUSI, GT .
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS, 1991, 9 (03) :1104-1108
[4]  
CHEN SW, 1999, J ELECT MAT, V28, P11
[5]  
CHOI HM, 1999, THESIS KAIST
[6]   Grain morphology of intermetallic compounds at solder joints [J].
Choi, WK ;
Jang, SY ;
Kim, JH ;
Paik, KW ;
Lee, HM .
JOURNAL OF MATERIALS RESEARCH, 2002, 17 (03) :597-599
[7]   Effect of soldering and aging time on interfacial microstructure and growth of intermetallic compounds between Sn-3.5Ag solder alloy and Cu substrate [J].
Choi, WK ;
Lee, HM .
JOURNAL OF ELECTRONIC MATERIALS, 2000, 29 (10) :1207-1213
[8]  
COTTE M, 1998, Patent No. 5800726
[9]   ELECTROCHEMICAL FABRICATION OF MECHANICALLY ROBUST PBSN C4 INTERCONNECTIONS [J].
DATTA, M ;
SHENOY, RV ;
JOHNES, C ;
ANDRICACOS, PC ;
HORKANS, J ;
DUKOVIC, JO ;
ROMANKIW, LT ;
ROEDER, J ;
DELIGIANNI, H ;
NYE, H ;
AGARWALA, B ;
TONG, HM ;
TOTTA, P .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1995, 142 (11) :3779-3785
[10]   NOTE ON THE ORIGIN OF INTRINSIC STRESSES IN FILMS DEPOSITED VIA EVAPORATION AND SPUTTERING [J].
DHEURLE, FM ;
HARPER, JME .
THIN SOLID FILMS, 1989, 171 (01) :81-92