MONOLITHIC CERAMIC CAPACITOR WITH BARIUM TITINATE DIELECTRIC CURIE POINT OPTIMIZED FOR ACTIVE IMPLANTABLE MEDICAL DEVICES OPERATING AT 37 DEGREES CENTIGRADE

摘要

A feedthrough filter capacitor assembly for use in active implantablemedical devices and a related process for manufacturing a monolithicceramic capacitor utilizing dielectric materials having a dielectric constantgreater than 7000, and preferably in the range of 8500 to 22,000. In themanufacture of the monolithic ceramic capacitor, one or more Curie pointshifters and/or other dopants are added to the dielectric material to optimizethe dielectric constant at the human body temperature of 37°C. Formanufacturing purposes, dopants may be added to the dielectric material tobroaden the Curie point peak or point of maximum dielectric constant thereof.The effect is that when such capacitors and terminal assemblies are utilizedin a high-voltage defibrillator circuit of an implantable medical device, thedielectric material is optimized so that during the delivery of high-voltageelectrical energy, capacitance value of the capacitor drops substantially.