The application discloses an apparatus comprising an optical die flip-chip bonded
to a substrate and defining a volume between the optical die and the substrate,
the optical die including an optically active area on a surface of the die facing
the substrate, an optically transparent material occupying at least those portions
of the volume substantially corresponding with the optically active area, and an
underfill material occupying portions of the volume not occupied by the optically
transparent material. Also disclosed is a process comprising flip-chip bonding
an optical die to a substrate, the optical die including at least one optically
active area on a surface thereof facing the substrate, dispensing an optically
transparent material between the optical die and the substrate, wherein the optically
transparent material covers the at least one optically active area, dispensing
an underfill material in the volume between the optical die and the substrate not
occupied by the optically transparent material, and curing the optically transparent
material and the underfill material. Other embodiments are described and claimed.