Microdot Epoxy Stamping Process Qualification For Substrate Based Optocoupler BGA Packaging

This paper investigates the adhesive stamping process qualification using an in-line modular machine for microdot application on substrate based package for microcoupler. Characterization of different stamping tool design yielded a rounded tip and star tip design for LED and photo detector die. While implementing plasma cleaning after premolding process yielded clean bonding pads for die attach process, resin bleed out phenomenon was detected due to high surface energy of the bonding pads after plasma. Implementing plasma is necessary to attain clean bonding pads after substrate cleaning, a work in characterizing dwell time after plasma yielded to a staging time of 4 hours before stamping process.