Chip size image sensor bumped package fabrication method

Abstract

To form an image sensor package, a window is mounted above an active area on an upper surface of an image sensor. The image sensor further includes a plurality of bond pads on the upper surface. Interior traces on a lower surface of a step up ring are aligned with the bond pads on the upper surface of the image sensor. Bumps are formed between the interior traces and the bond pads thus flip chip mounting the step up ring to the image sensor. The step up ring is mounted such that the window is located in or adjacent a central aperture of the step up ring. An underfill material is applied into the central aperture. The underfill material flows from the central aperture between the lower surface of the step up ring and the upper surface of the image sensor. The underfill material encloses the bumps. The underfill material is cured, if necessary, to form a package body. The package body enhances the reliability of the image sensor package by preventing the failure of the bumps and preventing the associated dismounting of the step up ring.

Dependencies are inferred from the claim text.