Investigation of under bump metallization systems for flip-chip assemblies

Author

Teo, Poi Siong ; Huang, Yu-Wen ; Tung, Chih Hang ; Marks, Michael Raj ; Lim, Thiam Beng

Author_Institution

Singapore Inst. of Microelectron., Singapore

fYear

2000

fDate

2000

Firstpage

33

Lastpage

39

Abstract

The objective of this work was to investigate the quality of Under Bump Metallization (UBM) systems used for solder bump flip chip applications. These three commercial UBM systems were (i)Al/NiV/Cu UBM with print-and-reflow solder, (ii)Ti-W/Cu UBM with electroplated solder and (iii) Electroless Ni/Au UBM with print-and-reflow solder. The solder was of an eutectic Sn/Pb composition. UBM quality in terms of thermal stability, corrosion-resistance and thermal-mechanical reliability were investigated using various multiple solder reflow passes, high temperature storage, pressure cooker test and temperature cycling. Analytical tools such as Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectrometry (EDS) were used to analyze the metallurgy reactions and failure modes. This study showed that none of the three systems investigated out-performed the other two in all aspects in the tests conducted

Keywords

flip-chip devices; metallisation; reflow soldering; Al-NiV-Cu; Ni-Au; Sn-Pb; Sn/Pb eutectic alloy; TiW-Cu; corrosion resistance; electroplated solder; energy dispersive X-ray spectrometry; failure mode; flip-chip assembly; high temperature storage; metallurgy reaction; multiple solder reflow; pressure cooker test; print-and-reflow solder; scanning electron microscopy; temperature cycling; thermal stability; thermal-mechanical reliability; transmission electron microscopy; under bump metallization; Failure analysis; Flip chip; Gold; Metallization; Scanning electron microscopy; Temperature; Testing; Thermal stability; Tin; Transmission electron microscopy;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronic Components & Technology Conference, 2000. 2000 Proceedings. 50th

Conference_Location

Las Vegas, NV

Print_ISBN

0-7803-5908-9

Type

conf

DOI

10.1109/ECTC.2000.853112

Filename

853112