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Direct‐bonded Al/Al 2 O 3 using a transient eutectic liquid phase
Author(s) -
Cheng YunHsiang,
Lin ChienCheng,
Lin KunLin
Publication year - 2020
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13489
Subject(s) - materials science , eutectic system , microstructure , annealing (glass) , scanning electron microscope , intermetallic , melting point , analytical chemistry (journal) , thermal conductivity , grain boundary , foil method , shear strength (soil) , metallurgy , composite material , alloy , chromatography , soil science , chemistry , environmental science , soil water
Abstract Directed bonding with Al and Al 2 O 3 was achieved using a transient liquid phase (TLP) method after annealing at the low melting point of Al, which deposited Ni, Cu, Ge, and Si on the Al 2 O 3 substrate. Al/Al 2 O 3 microstructures were evaluated using a scanning electron microscopy and transmission electron microscopy. A reaction layer was absent at the Al/Al 2 O 3 interface, and all deposited metal films dissolved into the Al foil and reacted with Al to form an eutectic liquid phase near the interface to wet and join with the Al 2 O 3 . Al 9 Fe 2 and Al 3 Fe intermetallic compounds were formed in the Al substrate because of Fe precipitation, which is an impurity of Al foil, and the reaction with Al at the grain boundaries of Al. The bonding area percentage, shear strength, and thermal conductivity for Al and Al 2 O 3 were assessed using scanning acoustic tomography (SAT), the ISO 13 124 shear strength test, and the laser flash method, respectively. The Al/Al 2 O 3 specimen deposited with the Ni film had the highest shear strength (33.74 MPa), thermal conductivity (42.3 W/mK), and bonding area percentage (96.78%). The Al/Al 2 O 3 specimens deposited with Ge and Si exhibited relatively poor bonding because of the oxidation of Ge and Si at the surface of Al 2 O 3 before bonding with Al.