1998 technology of materials, lasers, semiconductors, superconductors

technology of materials, lasers, semiconductors, superconductorsV 1500

33 - 305Oxidation and Reduction of Liquid SnPb (60/40) under Ambient andVacuum Conditions. — The prevention of oxidation in fluxless solderbonding is investigated. The growth of oxide films on metallic SnPb above theeutectic temp. is significantly reduced by decreasing the O2 partial pressure to≈10−5 Pa. The native oxide consists of SnO2 having an amorphous structure,whereas the oxide grown at 200 and 250 ◦C is crystalline SnO. The effectivenessof H2 to reduce SnO2 at typical soldering parameters (240 ◦C, ¡ 2 min) isfurthermore proved by in situ Auger electron spectroscopy. — (KUHMANN,J. F.; MALY, K.; PREUSS, A.; ADOLPHI, B.; DRESCHER, K.; WIRTH, T.;OESTERLE, W.; FANCIULLI, M.; WEYER, G.; J. Electrochem. Soc. 145(1998) 6, 2138-2142; Mikroelektron. Cent., Tech. Univ. Den., DK-2400 Lyngby,Den.; EN)

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