With the rapid advancement of information technologies
which has been seen in recent years, the use of
optoelectronic packages, such as planar light-wave circuit
modules, is increasing rapidly. In these packages, solder
alloys are commonly employed for the purpose of
mounting active devices, such as laser diodes, on the
substrate of the package [1]. The solder interconnection
of the module not only provides conventional functions,
such as heat dissipation, electrical connection and selfaligning
effects, but also helps to maintain the precise
alignment between the laser diode and the waveguide
during the use of the module. The solders used for the
application of these modules, therefore, must be resistant
to the creep deformation induced by stresses, such as
thermal stress, in the modules.
Solders for bonding applications in
microelectronic/optoelectronic packages are classified as
either soft solder or hard solder depending on their