Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 08, 2019 - September 11, 2019
In this paper, we challenge to strengthen Al/Ni-reactively-soldered single-crystal Si specimens. Al/Ni multilayer film in which Al and Ni are laminated at nanometer scale can produce NiAl intermetallic compound instantaneously by applying only a small energy, such as a small spark. During the compound formation, exothermic reaction is shown, which can be used to melt SnAg-solder for bonding Si wafers. After the solder bonding, four-point bending test is conducted to experimentally specify the weakest material or interface in the bonded section. By the usage of the free-standing Al/Ni film, the weakest point changed to the Si–interlayer interface from the NiAl–Sn-Ag interface due to a reduction of the number of voids at the solder-NiAl interface. By changing to Sn-Ag solder sheet from deposited Sn-Ag film, crack propagation direction changed. Using free-standing Al/Ni multilayer film and rolled solder sheet is effective for improving the bending strength.
