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Low Temperature Bonding of Alumina/Alumina and Alumina/Copper in Air Using Sn3.5Ag4Ti(Ce, Ga) Filler.

Authors :
Chang, S. Y.
Chuang, T. H.
Yang, C. L.
Source :
Journal of Electronic Materials; Sep2007, Vol. 36 Issue 9, p1193-1198, 6p, 10 Diagrams, 2 Graphs
Publication Year :
2007

Abstract

Sn3.5Ag4Ti(Ce,Ga) active filler was used for joining alumina with alumina and alumina with copper at 250°C in air. The joining process was done without flux and without the need for pre-metallization of alumina or a protective atmosphere. After mechanical activation of the bonding surfaces of alumina and copper, the filler showed good wetting on both alumina and copper and led to a strong bond between alumina and copper. Through tensile testing, a bonding strength of 23.7 MPa was found in the alumina/copper joint region. The shear strengths for alumina/alumina, copper/copper and alumina/copper joints were 13.5, 14.3, and 10.2 MPa, respectively. The affinity of cerium for oxygen protects titanium from oxidation, giving rise to the reaction of titanium with alumina at such a low temperature. Electron probe microanalyzer (EPMA) elemental mapping revealed that titanium segregates effectively at the alumina/solder interfaces. After aging tests at 200°C and 150°C, a double layer of Cu<subscript>3</subscript>Sn and Cu<subscript>6</subscript>Sn<subscript>5</subscript> intermetallic compound was formed at the solder/copper interfaces. With an increase of aging periods, the amount of brittle compound in the joints increased and resulted in decreases in the shear strengths of the alumina/copper joints. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
03615235
Volume :
36
Issue :
9
Database :
Complementary Index
Journal :
Journal of Electronic Materials
Publication Type :
Academic Journal
Accession number :
27656238
Full Text :
https://doi.org/10.1007/s11664-007-0190-9