A microelectronic imager having an imaging unit and an optics unit
attached to the imaging unit, and methods for packaging microelectronic
imagers. In one embodiment, the imaging unit can include a
microelectronic die with an image sensor and a plurality of external
contacts electrically coupled to the image sensor and a first referencing
element fixed to the imaging unit. The optics unit can include an optic
member and a second referencing element fixed to the optics unit. The
second referencing element is seated with the first referencing element
at a fixed, preset position in which the optic member is situated at a
desired location relative to the image sensor.