BALL PLACEMENT IN A PHOTO-PATTERNED TEMPLATE FOR FINE PITCH INTERCONNECT

摘要

A photo-patternable polymer film is deposited on a substrate, wherein the substrate includes metal pads. Ultraviolet light is transmitted through a photomask on the deposited photopatternable polymer film to generate cavities in the deposited polymer film and expose the metal pads. The substrate is developed and rinsed, and then flux is applied on the surface of the substrate. Balls are placed in the generated cavities. A reflow process is performed to form bumps and remove flux, subsequent to the placing of the balls in the generated cavities. Plasma cleaning is performed to remove the photo-patternable film.