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.