Inductor capacitor EMI filter for human implant applications

Abstract

A feedthrough terminal assembly for an active implantable medical device includes a conductive ferrule conductively coupled to a housing of the medical device, a feedthrough capacitor conductively coupled to the ferrule, an inductor closely associated with the capacitor in non-conductive relation, and a conductive terminal pin extending through the capacitor and the inductor. The terminal pin extends through the inductor in non-conductive relation and is conductively coupled to active electrode plates of the capacitor. In one preferred form, the terminal pin is wound about the inductor. Additionally, the inductor may be maintained in close association with the capacitor without forming a direct physical attachment therebetween.

1 - 172 . (canceled)  
   
   
       173 . A feedthrough terminal assembly, comprising: 
 a conductive ferrule;    a feedthrough capacitor having first and second sets of electrode plates;    an inductor with having a surface bonded to an opposing surface of the capacitor to create a laminate structure; and    a conductive terminal pin extending through the capacitor and conductively coupled to the first set of electrode plates, and extending through the inductor in non-conductive relation thereto.    
   
   
       174 . The assembly of  claim 173 , wherein the terminal pin is wound around the inductor and adjacent portions of the wound terminal pin are electrically insulated from one another.  
   
   
       175 . The assembly of  claim 174 , wherein the adjacent portions of the wound terminal pin are encased in a non-conductive material.  
   
   
       176 . The assembly of  claim 175 , wherein the adjacent portions of the wound terminal pin are encased within a non-conductive sleeve.  
   
   
       177 . The assembly of  claim 173 , wherein the inductor includes a notch for receiving the wound terminal pin.  
   
   
       178 . The assembly of  claim 177 , including a ramp formed in the notch.  
   
   
       179 . The assembly of  claim 177 , wherein the inductor includes multiple notches therein.  
   
   
       180 . The assembly of  claim 179 , wherein each notch accommodates a separate terminal pin therein.  
   
   
       181 . The assembly of  claim 177 , wherein the notch includes multiple slots for receiving corresponding multiple turns of the terminal pin.  
   
   
       182 . The assembly of  claim 177 , wherein the notch comprises contoured corners for accommodating the terminal pin.  
   
   
       183 . The assembly of  claim 173 , including means for maintaining the inductor in close association with the capacitor without forming a direct physical attachment therebetween.  
   
   
       184 . The assembly of  claim 183 , wherein the maintaining means comprises a lock associated with the terminal pin.  
   
   
       185 . The assembly of  claim 184 , wherein the lock comprises a mechanical lock.  
   
   
       186 . The assembly of  claim 184 , wherein the lock comprises a deformation in the terminal pin.  
   
   
       187 . The assembly of  claim 184 , wherein the lock comprises a cured polymer.  
   
   
       188 . The assembly of  claim 183 , wherein the maintaining means comprises a wire bond pad attached to the terminal pin.  
   
   
       189 . The assembly of  claim 188 , including a non-conductive substrate disposed between the wire bond pad and the inductor.  
   
   
       190 - 231 . (canceled)  
   
   
       232 . The assembly of  claim 173 , wherein the inductor is bonded to the capacitor with a non-conductive material.  
   
   
       233 . The assembly of  claim 232 , wherein the non-conductive material comprises polyimide.  
   
   
       234 . The assembly of  claim 232 , wherein the non-conductive material comprises a washer disposed between the inductor and the capacitor.  
   
   
       235 . The assembly of  claim 234 , wherein the washer is comprised of polyimide.  
   
   
       236 . The assembly of  claim 234 , wherein the washer comprises a thin-film, adhesive-backed washer.  
   
   
       237 . The assembly of  claim 173 , wherein the inductor comprises a high permeability ferrite material.  
   
   
       238 . The assembly of  claim 237 , wherein the inductor comprises a material selected from cobalt zinc ferrite, nickel zinc ferrite, manganese zinc ferrite, powdered iron, or molypermalloy.  
   
   
       239 . The assembly of  claim 173 , including a conformal coating over the inductor.  
   
   
       240 . The assembly of  claim 239 , wherein the conformal coating comprises Paralyne.  
   
   
       241 . The assembly of  claim 240 , wherein the conformal coating comprises Paralyne C, D, E, or N.  
   
   
       242 . The assembly of  claim 173 , including an insulator disposed between the inductor and the terminal pin.  
   
   
       243 . The assembly of  claim 242 , wherein the insulator comprises a non-conductive polymer.  
   
   
       244 . The assembly of  claim 243 , wherein the non-conductive polymer comprises an epoxy, a thermal-setting non-conductive adhesive, a non-conductive polyimide, or a silicone material.  
   
   
       245 . The assembly of  claim 173 , including a second inductor through which the terminal pin extends in non-conductive relation.  
   
   
       246 . The assembly of  claim 245 , wherein the inductors are disposed adjacent to one another.  
   
   
       247 . The assembly of  claim 246 , comprising at least one additional inductor stacked onto another one of the inductors.  
   
   
       248 . The assembly of  claim 246 , wherein the inductors are each comprised of materials having different physical or electrical properties.  
   
   
       249 . The assembly of  claim 246 , wherein the inductors are each comprised of materials having the same physical or electrical properties.  
   
   
       250 . The assembly of  claim 173 , wherein the capacitor and the inductor are housed within the ferrule.  
   
   
       251 . The assembly of  claim 250 , including an insulative cap disposed over the inductor opposite the capacitor.  
   
   
       252 . The assembly of  claim 247 , wherein the inductors are disposed on opposite sides of the capacitor.  
   
   
       253 . The assembly of  claim 252 , wherein at least one of the inductors is disposed on a body fluid side of the feedthrough terminal assembly.  
   
   
       254 . The assembly of  claim 247 , wherein the second inductor is disposed adjacent to the ferrule.  
   
   
       255 . The assembly of  claim 247 , wherein the inductors are disposed adjacent to opposing surfaces of the capacitor.  
   
   
       256 . The assembly of  claim 255 , wherein the inductors are bonded to the capacitor.  
   
   
       257 . The assembly of  claim 255 , wherein the capacitor and the inductors are disposed within and conductively isolated from the ferrule.  
   
   
       258 . The assembly of  claim 173 , wherein the capacitor is disposed on a body fluid side of the feedthrough terminal assembly.  
   
   
       259 . The assembly of  claim 173 , wherein the feedthrough capacitor comprises first and second feedthrough capacitors associated with the inductor in non-conductive relation.  
   
   
       260 . The assembly of  claim 259 , wherein the first and second feedthrough capacitors are disposed adjacent to opposing surfaces of the inductor.  
   
   
       261 . The assembly of  claim 260 , wherein the capacitors are bonded to opposite surfaces of the inductor.  
   
   
       262 . The assembly of  claim 260 , wherein each capacitor is internally grounded.  
   
   
       263 . The assembly of  claim 260 , wherein the first and second capacitors each include a first set of electrode plates conductively coupled to the terminal pin, and a second set of electrode plates conductively coupled to the ferrule.  
   
   
       264 . The assembly of  claim 263 , wherein the first capacitor comprises an externally grounded capacitor, and the second capacitor comprises an internally grounded capacitor, the feedthrough terminal assembly further including a conductive material extending through both the first and second feedthrough capacitors to conductively couple the second set of electrode plates of the second capacitor with the second set of electrode plates of the first capacitor.  
   
   
       265 . The assembly of  claim 264 ,-wherein the first and second feedthrough capacitors are disposed adjacent to opposing surfaces of the inductor.  
   
   
       266 . The assembly of  claim 264 , wherein the conductive material comprises a thermal setting conductive adhesive, a solder, or a solder paste.  
   
   
       267 . The assembly of  claim 264 , wherein the conductive material comprises a conductive pin.  
   
   
       268 . The assembly of  claim 267 , wherein the conductive pin comprises a nail head pin.  
   
   
       269 . The assembly of  claim 264 , wherein the conductive pin comprises a pin attached to an underlying hermetic insulator.  
   
   
       270 . The assembly of  claim 173 , including an hermetic insulator disposed between the terminal pin and the ferrule, wherein the capacitor is disposed adjacent to the hermetic insulator.  
   
   
       271 . The assembly of  claim 270 , wherein the inductor and the capacitor each include an aperture through which a leak detection gas can be detected.  
   
   
       272 . The assembly of  claim 173 , wherein the capacitor's second set of electrode plates are externally grounded to the ferrule.  
   
   
       273 . The assembly of  claim 173 , wherein the capacitor's second set of electrode plates are internally grounded to the ferrule.