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Wetting in an Electronic Packaging Ceramic System: 1, Wetting of Tungsten by Glass in Controlled Oxygen Partial Pressure Atmospheres
Author(s) -
Lazaroff Jerold E.,
Ownby P. Darrell,
Weirauch Douglas A.
Publication year - 1995
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1995.tb08211.x
Subject(s) - contact angle , wetting , sessile drop technique , partial pressure , isothermal process , oxygen , tungsten , adsorption , materials science , drop (telecommunication) , analytical chemistry (journal) , wetting transition , surface energy , ceramic , chemistry , mineralogy , composite material , thermodynamics , metallurgy , chromatography , organic chemistry , telecommunications , physics , computer science
The wetting of tungsten by a Cr 2 O 3 ‐colored, CaO‐MgO‐Al 2 O 3 ‐SiO 2 glass was found to be independent of temperature between 1300° and 1500°C, but strongly dependent on furnace atmosphere. Similar results using two gas buffer systems (CO/CO 2 and H 2 /H 2 O) established oxygen partial pressure, p 02 as the critical parameter. The contact angle decreased over a narrow p 02 range as the p 02 increased, with a stable contact angle existing in both lower and higher p 02 ranges. The solid‐liquid interfacial energy, γ SL , controlled the wetting behavior. An increase in the adsorbed oxygen layer at the solid‐liquid interface resulted in a lower γ SL and a lower contact angle. The equilibrium contact angles, established after 8‐h isothermal holds, ranged from 50‐55° at a p 02 = 10 −15.5 atm to 30° at a p 02 = 10 −10.9 atm. Two different drop formation techniques were used to show that the temperature and atmospheric conditions at the time of solid‐liquid interface formation affect the stable contact angles. The contact angle was higher when the solid‐liquid interface was established at the test temperature (doser tube technique) than when the drop was formed in situ from a piece of glass placed on the substrate at room temperature (nondoser method). This contact angle difference was again attributed to a higher γ SL from the doser method due to the presence of less adsorbed oxygen at the time of the creation of the solid‐liquid interface.