Fluxless wetting properties of the UBM-coated Si-wafer to pH-free solders under different atmosphere

Citation
Sm. Hong et al., Fluxless wetting properties of the UBM-coated Si-wafer to pH-free solders under different atmosphere, MATER TRANS, 42(3), 2001, pp. 520-527
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science & Engineering
Journal title
MATERIALS TRANSACTIONS
ISSN journal
1345-9678 → ACNP
Volume
42
Issue
3
Year of publication
2001
Pages
520 - 527
Database
ISI
SICI code
1345-9678(200103)42:3<520:FWPOTU>2.0.ZU;2-C
Abstract
The wetting balance method was used to estimate the fluxless wetting proper ties of UBM ((U) under bar nder (B) under bar ump (M) under bar etallurgy)- coated Si-wafer to binary lead-free solders (SnAg, SnSb, SnBi, Snln. SnZn). The wetting property estimation of UBM-coated Si-wafer was possible with n ew wettability indices from the wetting curves of one side-coated specimens : F-min, F-s and t(s). Au/Cu/Cr UBM is better than Au/Ni/Ti UBM from the po int of wetting time. AL general reflow process temperature, the wettability of high melting point solders (SnSb, SnAg) is better than that of low melt ing point ones (SnBi, Snln). The nitrogen atmosphere was more effective for improvement in fluxless wettability than in fluxed wettability. The contac t angle of one side-coated Si-plate to solder can be calculated from the fo rce balance equation by measuring the static state force and the tilt angle .