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CMOS image sensor (CIS) modules combine a CIS die with an optical system, a processor, and passives into a single package, such as chip-on-board, chip-scale packaging, or flipchip. A typical camera module is composed of an image sensor die, a carrier (ceramic or laminate), an IR filter, a lens barrel with optical elements, a lens holder, a processing chip, passive components and a flexible lead with connectors. Currently, the general concept of camera module assembly undergoes a transition from discrete assembly to wafer-level integration using well-established semiconductor technologies.
Wafer-level cameras (WLCs) are devices in which all individual parts are fabricated at wafer level, which are then bonded to form one single part composed of a CIS and a micro-optics stack, enhancing the light-capture efficiency of the camera. WLCs have already started to replace conventional modules due to their smaller form factor and lower cost. The latest version of WLCs has wafer-level optics, wafer-level packaging, and back-side illumination.
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Conventional camera vs. wafer level camera. Courtesy of Tessera.
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