Abstract
Soldering technique using formic acid is being applied to power module’s assembly process, but detailed research on this process
has been few reported. This paper presents the results of basic evaluation focusing on the gas generated by chemical reduction with
formic acid atmosphere and reduction rate. It was observed that a compound of formic acid and tin oxide was formed at 150℃, and
the compound was decomposed into hydrogen and carbon dioxide at 180℃ or higher. Furthermore, it was found that the chemical
reduction rate of tin oxide is proportional to the temperature and concentration of formic acid if the amount of formic acid is more
than the amount of oxide, but it does not increase if the amount of formic acid is less than the amount of oxide.
