US Patent 11114483 Cavityless chip-scale image-sensor package

A cavityless chip-scale image-sensor package includes a substrate, a microlens array, and a low-index layer. The substrate includes a plurality of pixels forming a pixel array. The microlens array includes a plurality of microlenses each (i) having a lens refractive index, (ii) being aligned to a respective one of the plurality of pixels and (iii) having a non-planar microlens surfaces facing away from the respective one of the plurality of pixels. The low-index layer has a first refractive index less than the lens refractive index. The low-index layer also includes a bottom surface, at least part of which is conformal to each non-planar microlens surface. The microlens array is between the pixel array and the low-index layer.