ABSTRACT

Solders such as the 48Sn-52In (wt%) have been studied as interconnect materials in a vertical-cavity surface-emitting laser (VCSEL). The 48Sn-52In alloy is a low-temperature (melting point = 118°C) lead-free (Pb-free) solder and a potential candidate material for this device. In recent years, the integration of VCSELs onto integrated circuits has become a topic of intense research. An important focus of this research has been to develop and adapt methodologies to electrically connect VCSELs to electronic chips, including wire bonding, bridge bonding, and flip-chip bonding. Of these, the lattermost (i.e., flip-chip bonding) has proven to be the most promising chip-level packaging for this application.