One aspect provides a method of forming a feedthrough device for an implantable medical device. The method includes providing a bulk insulator having a longitudinal length extending between first and second end faces, and including one or more conducting elements extending therethrough between the first and second end faces, the bulk insulator having a perimeter surface along the longitudinal length, and depositing one of a metal, metal alloy, or cermet on the perimeter surface to form a ferrule directly thereon, wherein the ferrule can be joined to other components of the implantable medical device.