Controlled depth etched dielectric film

A dielectric film for use as a substrate for a flexible circuit comprises a polymer selected from the group consisting of liquid crystal polymers and polyimide copolymers including carboxylic ester structural units in the polymeric backbone. The dielectric film has a thickness from about 25 mum to about 60 mum including at least one thinned, recessed region wherein the thickness is reduced to less than 15 mum, as required for use of the dielectric film in e.g. ink jet print head, hard disk drive head gimbal assembly and touch sensor applications.