Feedthrough capacitor having reduced self resonance insertion loss dip

• US 7,623,336 B2
• Filed: 05/31/2007
• Issued: 11/24/2009
• Est. Priority Date: 06/01/2006
• Status: Expired due to Fees

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Inventors: Frysz, Christine A., Dabney, Warren S., Stevenson, Robert A.
• Primary Examiner(s): Ha; Nguyen T
• Application Number:
  US11/756,038
• Publication Number:
  US 20070279834A1
• Time in Patent Office: 908 Days
• Field of Search: 361/302, 361303-305, 361/306.1, 361/306.3, 361/321.1, 361/321.2, 607/5, 607/7, 607/9
• US Class Current: 361/302
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: H01G 4/35 Feed-through capacitors or anti-noise capacitors

Abstract

The self-resonance insertion loss dip of a feedthrough capacitor is reduced or eliminated by raising the equivalent series resistance of the capacitor, thus minimizing the capacitor Q. The equivalent series resistance of the capacitor can be raised by forming voids in the active and/or ground electrode plates of the capacitor. The electrode plates may be formed so as to have a relatively reduced thickness, or a relatively increased thickness. A conductive material having a relatively high resistivity may be used to form the active and/or ground electrode plates of the capacitor. Alternatively, the conductive material forming the electrode plates may have a dielectric material added thereto.

Claims

1. A feedthrough capacitor, comprising:

a dielectric body having a passageway therethrough;

an active electrode plate disposed within the body and having an end terminating at the passageway; and

a ground electrode plate disposed within the body in spaced relation to the active electrode plate, the ground electrode plate having a portion terminating at a point spaced from and in electrical isolation from the active electrode plate termination;

wherein capacitor Q is relatively minimized and equivalent series resistance of the capacitor relatively increased to reduce or eliminate self-resonance insertion loss dip of the capacitor.

2. The feedthrough capacitor of claim 1, wherein the active electrode plate includes voids therein.

3. The feedthrough capacitor of claim 2, wherein the active electrode plate includes an outer boundary, and an inner boundary adjacent to the capacitor passageway, wherein the voids are disposed between the outer and inner boundary.

4. The feedthrough capacitor of claim 2, wherein the voids comprise apertures, gaps, slits or spokes formed in the active electrode plate.

5. The feedthrough capacitor of claim 2, wherein the voids comprise a pattern of voids formed in the active electrode plate.

6. The feedthrough capacitor of claim 1, wherein the ground electrode plate includes voids therein.

7. The feedthrough capacitor of claim 6, wherein the ground electrode plate includes an outer boundary, and an inner boundary adjacent to the capacitor passageway, wherein the voids are disposed between the outer and inner boundary.

8. The feedthrough capacitor of claim 6, wherein the voids comprise apertures, gaps, slits or spokes formed in the ground electrode plate.

9. The feedthrough capacitor of claim 6, wherein the voids comprise a pattern of voids formed in the ground electrode plate.

10. The feedthrough capacitor of claim 1, wherein the active electrode plate is of a relatively reduced thickness.

11. The feedthrough capacitor of claim 10, wherein the active electrode plate is between 0.1 nanometer and 10 microns in thickness.

12. The feedthrough capacitor of claim 1, wherein the ground electrode plate is of a relatively reduced thickness.

13. The feedthrough capacitor of claim 12, wherein the ground electrode plate is between 0.1 nanometer and 10 microns in thickness.

14. The feedthrough capacitor of claim 1, wherein the active electrode plate is comprised of a conductive material having a relatively high resistivity.

15. The feedthrough capacitor of claim 14, wherein the active electrode plate is comprised of base metal electrodes (nickel), palladium silver electrodes or palladium electrodes, platinum electrodes or ternary electrodes consisting of gold, platinum or palladium.

16. The feedthrough capacitor of claim 1, wherein the ground electrode plate is comprised of a conductive material having a relatively high resistivity.

17. The feedthrough capacitor of claim 16, wherein the ground electrode plate is comprised of base metal electrodes (nickel), palladium silver electrodes or palladium electrodes, platinum electrodes or ternary electrodes consisting of gold, platinum or palladium.

18. The feedthrough capacitor of claim 1, wherein the active electrode plate has a greater length than width.

19. The feedthrough capacitor of claim 1, wherein the ground electrode plate has a greater length than width.

20. The feedthrough capacitor of claim 1, wherein the active electrode plate is comprised of a conductive material having a dielectric material added thereto.

21. The feedthrough capacitor of claim 20, wherein the conductive material comprises electrode ink having dielectric powder added thereto.

22. The feedthrough capacitor of claim 1, wherein the ground electrode plate is comprised of a conductive material having a dielectric material added thereto.

23. The feedthrough capacitor of claim 22, wherein the conductive material comprises electrode ink having dielectric powder added thereto.

24. The feedthrough capacitor of claim 1, including a resistor disposed in series with the capacitor.

25. The feedthrough capacitor of claim 24, wherein the resistor comprises a distributive resistance between a capacitor termination material and a contact point of the electrode.

26. The feedthrough capacitor of claim 1, wherein the dielectric body comprises a material having high dielectric loss tangents at a selected frequency.