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.
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:
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:
The high-voltage and/or high-frequency pulse dielectric breakdown strength (DBS) of an implantable medical device is increased by strategically positioning insulation materials on or adjacent to the external surfaces of a filter capacitor. Dielectric breakdown strength is further increased by adding polymeric or ceramic nanoscale metal oxide insulative powders to the insulation materials.
Abstract:
A miniature electrochemical cell having a total volume that is less than 0.5 cc is described. The cell casing is formed by joining two ceramic casing halves together. One or both casing halves are machined from ceramic to provide a recess that is sized and shaped to contain the electrode assembly. The opposite polarity terminals are electrically conductive feedthroughs or pathways, such as of gold, and are formed by brazing gold into tapered via holes machined into one or both ceramic casing halves. The two ceramic casing halves are separated from each other by a metal interlayer, such as of gold, bonded to a thin film metallization layer, such as of titanium, that contacts an edge periphery of each ceramic casing half. A solid electrolyte of LiPON (LixPOyNz) is used to activate the electrode assembly.
Abstract:
A miniature electrochemical cell having a total volume that is less than 0.5 cc is described. The cell casing is formed by joining two ceramic casing halves together. One or both casing halves are machined from ceramic to provide a recess that is sized and shaped to contain the electrode assembly. The opposite polarity terminals are metal feedthroughs, such as of gold, and are formed by brazing gold into openings machined into one or both of ceramic casing halves. A thin film metallization, such as of titanium, contacts an edge periphery of each ceramic casing half. The first ceramic casing half is moved into registry with the second ceramic casing half so that the first and second ring-shaped metallizations contact each other. Then, a laser welds through one of the casing halves being a substantially transparent ceramic, for example sapphire, to braze the first and second ring-shaped metallizations to each other to thereby join the first and second casing halves together to form a casing housing the electrode assembly. A solid electrolyte (LixPOyNz) activates the electrode assembly.
Abstract:
A hermetically sealed filtered feedthrough assembly attachable to an AIMD includes an insulator hermetically sealing the opening of a ferrule with a gold braze. The ferrule includes a peninsula extending into the ferrule opening and the insulator has a cutout matching the peninsula. A sintered platinum-containing paste hermetically seals at least one via hole extending through the insulator. At least one capacitor is disposed on the device side. An active electrical connection electrically connects the capacitor active metallization to the sintered paste. A ground electrical connection electrically connects the capacitor ground metallization disposed within a capacitor ground passageway to the portion of the gold braze along the ferrule peninsula. The dielectric of the capacitor may be less than 1,000 k.
Abstract:
A feedthrough for an AIMD includes a ferrule with an insulator hermetically sealing a ferrule opening, both cooperatively separating a body fluid side from a device side. A circuit board disposed adjacent to the insulator device side has a ground plate or ground trace electrically connected to a circuit board ground conductive pathway disposed in a circuit board ground via hole. An anisotropic conductive layer disposed between the circuit board and the insulator device side has an electrically insulative matrix supporting a plurality of electrically conductive particles. The anisotropic conductive layer has a first thickness where at least one first electrically conductive particle is longitudinally aligned and in electrical contact with the ferrule and the circuit board ground conductive pathway electrically connected to the at least one circuit board ground plate or ground trace. The anisotropic conductive layer has a second, greater thickness where the ferrule and the circuit board ground conductive pathway are not longitudinally aligned, and no electrically conductive particles are in electrical contact with the ferrule and the circuit board ground conductive pathway.
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 miniature electrochemical cell having a volume of less than 0.5 cc is described. The cell has a casing of first and second ceramic substrates that are hermetically secured to each other to provide an internal space housing an electrode assembly. First and second conductive pathways extend through the ceramic substrates. The pathways have respective inner surfaces that are conductively connected to the respective anode and cathode current collectors and respective outer surfaces that provide for connection to a load. An electrolyte in the internal space of the housing activates the electrode assembly.