An implantable device has a hermetically sealed enclosure, an electronic device within the hermetically sealed enclosure, and a plurality of feedthrough conductors in mechanical contact with the hermetically sealed enclosure and exposed outside of the hermetically sealed enclosure. The implantable device also has a flexible substrate with a plurality of therapy contacts, and a plurality of continuously conductive elements extending along the flexible substrate from the array of therapy contacts and terminating at a plurality of connection pads. Each of the continuously conductive element is integral with at least one therapy contact and at least one connection pad to electrically communicate the noted therapy contact(s) and the noted connection pad(s). The thickness of each continuously conductive element may be between about 5 and 190 microns. The implantable device also has a plurality of mechanical welded couplings that each couple at least one of the connection pads.