Abstract:
A method of manufacturing a feedthrough dielectric body for an active implantable medical device includes the steps of: a) forming an alumina ceramic body in a green state, or, stacking upon one another discrete layers of alumina ceramic in a green state and pressing; b) forming at least one via hole straight through the alumina ceramic body; c) filling the at least one via hole with a ceramic reinforced metal composite paste; d) drying the alumina ceramic body and the ceramic reinforced metal composite paste; e) forming a second hole straight through the ceramic reinforced metal composite paste being smaller in diameter in comparison to the at least one via hole; f) filling the second hole with a substantially pure metal paste; g) sintering the alumina ceramic body, the ceramic reinforced metal composite paste and the metal paste; and h) hermetically sealing the feedthrough dielectric body to a ferrule.
Abstract:
A hermetically sealed filtered feedthrough assembly attachable to an AIMD includes an insulator hermetically sealing a ferrule opening of an electrically conductive ferrule with a gold braze. A co-fired and electrically conductive sintered paste is disposed within and hermetically seals at least one via hole extending in the insulator. At least one capacitor is disposed on the device side. An active electrical connection electrically connects a capacitor active metallization and the sintered paste. A ground electrical connection electrically connects the gold braze to a capacitor ground metallization, wherein at least a portion of the ground electrical connection physically contacts the gold braze. The dielectric of the capacitor may be less than 1000 k. The ferrule may include an integrally formed peninsula portion extending into the ferrule opening spatially aligned with a ground passageway and metallization of an internally grounded feedthrough capacitor. The sintered paste may be of substantially pure platinum.
Abstract:
Disclosed herein are electrically conductive and hermetic vias disposed within an insulator substrate of a feedthrough assembly and methods for making and using the same. Such aspects of the present invention consequently provide for the miniaturization of feedthrough assemblies inasmuch as the feedthrough components of the present invention are capable of supporting very small and hermetic conductively filled via holes in the absence of additional components, such as, for example, terminal pins, leadwires, and the like.
Abstract:
A method of manufacturing a feedthrough dielectric body for an active implantable medical device includes the steps of: a) forming an alumina ceramic body in a green state, or, stacking upon one another discrete layers of alumina ceramic in a green state and pressing; b) forming at least one via hole straight through the alumina ceramic body; c) filling the at least one via hole with a ceramic reinforced metal composite paste; d) drying the alumina ceramic body and the ceramic reinforced metal composite paste; e) forming a second hole straight through the ceramic reinforced metal composite paste being smaller in diameter in comparison to the at least one via hole; f) filling the second hole with a substantially pure metal paste; g) sintering the alumina ceramic body, the ceramic reinforced metal composite paste and the metal paste; and h) hermetically sealing the feedthrough dielectric body to a ferrule.
Abstract:
A feedthrough filter capacitor assembly comprising a terminal pin connector is described. The terminal pin connector is designed to facilitate an electrical connection between the terminal pin comprising a multitude of compositions to a circuit board of an implantable medical device. The terminal pin connector comprises a clip portion positioned within a connector housing. The connector clip mechanically attaches to the terminal pin of the feedthrough with at least one prong and an exterior surface of the connector housing electrically contacts the circuit board, creating an electrical connection therebetween. The connector housing comprises a material that is conducive to a weld or solder attachment process to the circuit board. The feedthrough filter capacitor assembly is particularly useful for incorporation into implantable medical devices such as cardiac pacemakers, cardioverter defibrillators, and the like, to decouple and shield internal electronic components of the medical device from undesirable electromagnetic interference (EMI) signals.
Abstract:
A co-fired hermetically sealed feedthrough is attachable to an active implantable medical device. The feedthrough comprises an alumina dielectric substrate comprising at least 96 or 99% alumina. A via hole is disposed through the alumina dielectric substrate from a body fluid side to a device side. A substantially closed pore, fritless and substantially pure platinum fill is disposed within the via hole forming a platinum filled via electrically conductive between the body fluid side and the device side. A hermetic seal is between the platinum fill and the alumina dielectric substrate, wherein the hermetic seal comprises a tortuous and mutually conformal interface between the alumina dielectric substrate and the platinum fill.
Abstract:
An AIMD includes a conductive housing, an electrically conductive ferrule with an insulator hermetically sealing the ferrule opening. A conductive pathway is hermetically sealed and disposed through the insulator. A filter capacitor is disposed on a circuit board within the housing and has a dielectric body supporting at least two active and two ground electrode plates interleaved, wherein the at least two active electrode plates are electrically connected to the conductive pathway on the device side, and the at least two ground electrode plates are electrically coupled to either the ferrule and/or the conductive housing. The dielectric body has a dielectric constant less than 1000 and a capacitance of between 10 and 20,000 picofarads. The filter capacitor is configured for EMI filtering of MRI high RF pulsed power by a low ESR, wherein the ESR of the filter capacitor at an MRI RF pulsed frequency or range of frequencies is less than 2.0 ohms.
Abstract:
A co-connected hermetic feedthrough, feedthrough capacitor, and leadwire assembly includes a dielectric substrate with a via hole disposed through the dielectric substrate from a body fluid side to a device side. A conductive fill is disposed within the via forming a hermetic seal and is electrically conductive between the body fluid side and the device side. A feedthrough capacitor is attached to the dielectric substrate and includes a capacitor dielectric substrate, an unfilled capacitor via hole including an inner metallization, a set of capacitor active electrode plates electrically coupled to the inner metallization, an outer metallization disposed and a set of capacitor ground electrode plates electrically coupled to the outer metallization. A conductive leadwire is disposed within the unfilled capacitor via hole. An electrical joint connects the conductive fill, the capacitor inner metallization along with the capacitor active electrode plates and the conductive leadwire.
Abstract:
An RF filter for an active medical device (AMD), for handling RF power induced in an associated lead from an external RF field at a selected MRI frequency or range frequencies includes a capacitor having a capacitance of between 100 and 10,000 picofarads, and a temperature stable dielectric having a dielectric constant of 200 or less and a temperature coefficient of capacitance (TCC) within the range of plus 400 to minus 7112 parts per million per degree centigrade. The capacitor's dielectric loss tangent in ohms is less than five percent of the capacitor's equivalent series resistance (ESR) at the selected MRI RF frequency or range of frequencies.
Abstract:
An elevated feedthrough is attachable to a top or a side of an active implantable medical device. The feedthrough includes a conductive ferrule and a dielectric substrate. The dielectric substrate is defined as comprising a body fluid side and a device side disposed within the conductive ferrule. The dielectric substrate includes a body fluid side elevated portion generally raised above the conductive ferrule. At least one via hole is disposed through the dielectric substrate from the body fluid side to the device side. A conductive fill is disposed within the at least one via hole forming a hermetic seal and electrically conductive between the body fluid side and the device side. A leadwire connection feature is on the body fluid side electrically coupled to the conductive fill and disposed adjacent to the elevated portion of the dielectric substrate.