Hermetically sealed feedthrough with co-fired filled via and conductive insert for an active implantable medical device

A hermetically sealed feedthrough, comprising:

• a) an electrically conductive ferrule comprising a ferrule opening, wherein the ferrule is configured to be attachable to an opening in a housing of an active implantable medical device;
• b) a dielectric substrate at least partially residing in the ferrule opening where a gold braze hermetically seals the dielectric substrate to the ferrule, wherein at least one dielectric via hole extending through the dielectric substrate to spaced apart dielectric substrate first and second end surfaces has a dielectric via hole open volume;
• c) a platinum fill comprising at least 80% platinum particles mixed with at least one binder, wherein the platinum fill is disposed within the dielectric via hole to thereby occupy at least 80% of the dielectric via hole open volume,
• d) wherein, in a pre-sintered state, the dielectric substrate has a dielectric green-state volume and the platinum fill has a platinum fill green-state volume, and
• e) wherein, after having been sintered, the dielectric substrate having the at least one dielectric via hole provided with the platinum fill is characterized by the platinum fill having had the binder substantially volatilized to thereby provide a sintered platinum fill volume and a sintered dielectric substrate volume, and
• f) wherein the platinum fill sintered volume is less than the platinum fill green-state volume, and the dielectric sintered volume is less than the dielectric green-state volume, and
• g) wherein the dielectric difference between the dielectric sintered- and green-state volumes is from 14% to 20% greater than the platinum fill difference between the platinum fill sintered- and green-state volumes so that the dielectric substrate imparts a compressive force on the platinum fill to thereby provide a hermetically sealed and electrically conductive platinum pathway through the dielectric substrate between and to the dielectric substrate first and second end surfaces.