The present invention provides flip-chip packaging for optically
interactive devices such as image sensors and methods of assembly. In a
first embodiment of the invention, conductive traces are formed directly
on the second surface of a transparent substrate and an image sensor chip
is bonded to the conductive traces. Discrete conductive elements are
attached to the conductive traces and extend below a back surface of the
image sensor chip. In a second embodiment, a secondary substrate having
conductive traces formed thereon is secured to the transparent substrate.
In a third embodiment, a backing cap having a full array of attachment
pads is attached to the transparent substrate of the first embodiment or
the secondary substrate of the second embodiment. In a fourth embodiment,
the secondary substrate is a flex circuit having a mounting portion
secured to the second surface of the transparent substrate and a backing
portion bent over adjacent to the back surface of the image sensor chip.