Richard Zhiwei Fu

US Patent:

7812691, Oct 12, 2010

Filed:

Nov 10, 2008

Appl. No.:

12/267932

Inventors:

Andrew E. Fisk - Philadelphia PA, US
Richard X. Fu - Ellicott City MD, US
Christine A. Frysz - Orchard Park NY, US

Assignee:

Greatbatch Ltd. - Clarence NY

International Classification:

H03H 7/00

US Classification:

333182

Abstract:

A feedthrough filter capacitor assembly is described. The feedthrough filter capacitor assembly comprises an outer ferrule hermetically sealed to an insulator of a dielectric material seated within the ferrule. The insulative material is also hermetically sealed to at least one lead wire. Instead of being made of platinum or platinum/iridium, the lead wire comprises a core of a non-noble metal supporting a functionally graded coating. The metal core has an inner layer of the same the non-noble metal of the core and an outer layer of a noble metal. A gradient transition zone exists between the non-noble metal and the outer noble metal. Consequently, lead wires having all the beneficial attributes of platinum and platinum/iridium wire can be built into hermetic feedthroughs, but at a significantly reduced cost. In a preferred form, a filter capacitor is mounted on the insulator and electrically connected to the lead wires and to the ferrule to prevent unwanted EMI signals from traveling along the wires and entering the interior of the medical device.