Methods of fabrication of package assemblies for optically interactive electronic devices and package assemblies therefor
Packaging assemblies for optically interactive devices and methods of forming the packaging assemblies in an efficient manner that eliminates or reduces the occurrence of process contaminants. In a first embodiment, a transparent cover is attached to a wafer of semiconductor material containing a plurality of optically interactive devices. The wafer is singulated, and the optically interactive devices are mounted on an interposer and electrically connected with wire bonds. In a second embodiment, the optically interactive devices are electrically connected to the interposer with back side conductive elements. In a third embodiment, the optically interactive devices are mounted to the interposer prior to attaching a transparent cover. A layer of encapsulant material is formed over the interposer, and the interposer and encapsulant material are cut to provide individual packaging assemblies. In a fourth embodiment, the optically interactive devices are mounted in a preformed leadless chip carrier.
1. An electronic device package assembly, comprising:
an interposer having at least one conductive pathway including an attachment pad on a surface thereof;
an optically interactive device mounted to the interposer and having a surface with an image sensitive area and at least one bond pad outside the image sensitive area;
a transparent cover bonded over the image sensitive area to the surface of the optically interactive device between a peripheral edge of the image sensitive area and the at least one bond pad;
an electrical connection between the at least one bond pad and the attachment pad of the at least one conductive pathway of the interposer wherein the electrical connection comprises a conductive trace extending from the at least one bond pad on the surface of the optically interactive device to another, opposing surface of the optically interactive device; and
a layer of encapsulant material over the surface of the interposer partially covering the optically interactive device and leaving the transparent cover substantially exposed.
2. The electronic device package assembly of claim 1 , wherein a peripheral edge of the transparent cover extends beyond the peripheral edge of the image sensitive area and short of the at least one bond pad of the optically interactive device.
3. The electronic device package assembly of claim 1 , wherein the at least one conductive pathway of the interposer includes an external connection point on another, opposing surface thereof.
4. The electronic device package assembly of claim 1 , further comprising a discrete conductive element attached to the external connection point of the at least one conductive pathway.
5. The electronic device package of claim 1 , wherein the optically interactive device is adhered to the interposer.
6. The electronic device package of claim 1 , wherein the encapsulant material comprises one of a silicon-filled polymer and a liquid crystal polymer.
7. The electronic device package of claim 1 , wherein the optically interactive device comprises an image sensor chip.
8. The electronic device package of claim 1 , wherein the electrical connection between the at least one bond pad of the optically interactive device and the attachment pad of the at least one conductive pathway of the interposer comprises a wire bond.