INJECTION MOLDED FERRULE FOR COFIRED FEEDTHROUGHS

• US 20110048770A1
• Filed: 01/26/2010
• Published: 03/03/2011
• Est. Priority Date: 08/31/2009
• Status: Abandoned Application

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Tischendorf, Brad C., Reiterer, Markus, Thom, Andrew
• Application Number:
  US12/693,772
• Publication Number:
  US 20110048770A1
• Time in Patent Office: Days
• US Class Current: 174/152.GM
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: B22F 3/225 by injection molding
• CPC Class Codes: B22F 5/10 of articles with cavities or holes, not otherwise provided for in the preceding subgroups
• CPC Class Codes: B22F 7/062 involving the connection or repairing of preformed parts
• CPC Class Codes: B22F 7/08 with one or more parts not made from powder B22F7/062 takes precedence
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/348 Zirconia, hafnia, zirconates or hafnates
• CPC Class Codes: C04B 2237/365 Silicon carbide
• CPC Class Codes: C04B 2237/368 Silicon nitride
• CPC Class Codes: C04B 2237/403 Refractory metals
• CPC Class Codes: C04B 2237/405 Iron metal group, e.g. Co or Ni
• CPC Class Codes: C04B 2237/406 Iron, e.g. steel
• CPC Class Codes: C04B 2237/408 Noble metals, e.g. palladium, platina or silver
• CPC Class Codes: C04B 2237/62 Forming laminates or joined articles comprising holes, channels or other types of openings
• CPC Class Codes: C04B 37/021 in a direct manner, e.g. direct copper bonding [DCB]
• CPC Class Codes: C22C 14/00 Alloys based on titanium
• CPC Class Codes: C22C 19/007 with a light metal (alkali metal Li, Na, K, Rb, Cs; earth alkali metal Be, Mg, Ca, Sr, Ba, Al Ga, Ge, Ti) or B, Si, Zr, Hf, Sc, Y, lanthanides, actinides, as the next major constituent
• CPC Class Codes: C22C 19/03 based on nickel
• CPC Class Codes: H01B 19/00 Apparatus or processes specially adapted for manufacturing insulators or insulating bodies manufacture of porcelain for electric insulation C04B33/26

Abstract

Feedthrough assemblies and methods of manufacturing feedthrough assemblies are provided. Methods include molding a ferrule comprising titanium using metal injection molding and positioning the ferrule about at least a portion of an insulator, the insulator comprising alumina. Methods also include overmolding a ferrule about at least a portion of an insulator using metal injection molding, the ferrule comprising titanium and the insulator comprising alumina. Sintering densifies the ferrule and provides a hermetic seal between the ferrule and insulator. The insulator may be fired or unfired prior to sintering of the ferrule.

Claims

1. A method of manufacturing a feedthrough assembly comprising:

overmolding a ferrule about at least a portion of an insulator using metal injection molding, the ferrule comprising titanium and the insulator comprising a high temperature cofired ceramic alumina (HTCC) or a member selected from the group consisting of alumina, toughened alumina, sapphire, silicon nitride, silicon carbide, zirconia, zircon, and combinations thereof; and

sintering to densify the ferrule and provide a hermetic seal between the ferrule and insulator.

2. The method of claim 1, wherein the insulator is a fired insulator or an unfired insulator.

3. The method of claim 1, wherein the insulator and ferrule are co-sintered in a single step.

4. The method of claim 1, wherein a metallization layer comprising a refractory metal is positioned between at least a portion of the ferrule and insulator.

5. The method of claim 1, wherein the metal injection molding comprises:

injecting a mixture of titanium particles and binding material into a mold for the ferrule to form a green part, wherein the insulator is positioned within at least part of the mold so that the green part is formed about at least a portion of the insulator;

removing the green part from the mold; and

debinding the green part to form a brown part.

6. The method of claim 5, wherein the insulator forms part of the geometry of the metal injection molded ferrule in the mold.

7. The method of claim 1, wherein the sintering to densify the ferrule includes heating to about 1300°

C.

8. The method of claim 1, wherein the hermetic seal is helium leak tight.

9. The method of claim 1, wherein the ferrule comprises titanium selected from the group consisting of pure titanium, nano-titanium, titanium-6Al-4V, titanium-vanadium, nickel-titanium, titanium-niobium, and mixtures thereof.

10. The method of claim 1, wherein the ferrule further comprises a member selected from the group consisting of niobium, platinum, molybdenum, zirconium, tantalum, vanadium, tungsten, iridium, rhodium, ruthenium, palladium, silver, stainless steel, nickel super alloy, nickel-cobalt-chromium-molybdenum alloy, alloys of these metals, and combinations thereof.

11. The method of claim 1, wherein the insulator further comprises at least one bore to receive an electrically conductive terminal pin or via and pad.

12. A feedthrough assembly manufactured according to the method of claim 1.

13. A method of manufacturing a feedthrough assembly comprising:

molding a ferrule using metal injection molding, the ferrule comprising titanium and the insulator comprising HTCC or a member selected from the group consisting of alumina, toughened alumina, sapphire, silicon nitride, silicon carbide, zirconia, zircon, and combinations thereof;

positioning the ferrule about at least a portion of an insulator; and

sintering to densify the ferrule and provide a hermetic seal between the ferrule and insulator.

14. The method of claim 13, wherein the insulator is a fired insulator or an unfired insulator.

15. The method of claim 13 wherein the insulator and ferrule are co-sintered in a single step.

16. The method of claim 13, wherein a metallization layer comprising a refractory metal is positioned between at least a portion of the ferrule and insulator.

17. The method of claim 13, wherein the metal injection molding comprises:

injecting a mixture of titanium particles and binding material into a mold for the ferrule to form a green part;

removing the green part from the mold; and

debinding the green part to form a brown part, wherein the brown part is provided as the ferrule in the positioning step.

18. The method of claim 13, wherein the sintering to densify the ferrule includes heating to about 1300°

C.

19. The method of claim 13, wherein the hermetic seal is helium leak tight.

20. The method of claim 13, wherein the ferrule comprises titanium selected from the group consisting of pure titanium, nano-titanium, titanium-6Al-4V, titanium-vanadium, nickel-titanium, titanium-niobium, and mixtures thereof.

21. The method of claim 13, wherein the ferrule further comprises a member selected from the group consisting of niobium, platinum, molybdenum, zirconium, tantalum, vanadium, tungsten, iridium, rhodium, ruthenium, palladium, silver, stainless steel, nickel super alloy, nickel-cobalt-chromium-molybdenum alloy, alloys of these metals, and combinations thereof.

22. The method of claim 13, wherein the insulator further comprises at least one bore to receive an electrically conductive terminal pin or via and pad.

23. A feedthrough assembly manufactured according to the method of claim 13.

24. A feedthrough assembly comprising a ferrule positioned about a least a portion of an insulator, the ferrule comprising titanium and the insulator comprising HTCC or a member selected from the group consisting of alumina, toughened alumina, sapphire, silicon nitride, silicon carbide, zirconia, zircon, and combinations thereof, wherein the ferrule and insulator are hermetically sealed without the use of brazing or joining material or glass.

25. The feedthrough assembly of claim 24, further comprising a metallization layer comprising a refractory metal positioned between at least a portion of the ferrule and insulator.

26. The feedthrough assembly of claim 24, wherein the hermetic seal is helium leak tight.

27. The feedthrough assembly of claim 24, wherein the ferrule comprises titanium selected from the group consisting of pure titanium, nano-titanium, titanium-6Al-4V, titanium-nickel, titanium-vanadium, titanium-niobium, and mixtures thereof.

28. The feedthrough assembly of claim 24, wherein the ferrule further comprises a member selected from the group consisting of niobium, platinum, molybdenum, zirconium, tantalum, vanadium, tungsten, iridium, rhodium, ruthenium, palladium, silver, stainless steel, nickel super alloy, nickel-cobalt-chromium-molybdenum alloy, alloys of these metals, and combinations thereof.

29. The feedthrough assembly of claim 24, wherein the insulator further comprises at least one bore, wherein the bore includes an electrically conductive terminal pin or via and pad.

30. The feedthrough assembly of claim 24, wherein the terminal pin or via and pad comprise a member of the group consisting of niobium, tantalum, nickel-titanium, titanium, beta titanium, titanium alloys, stainless steel, molybdenum, tungsten, platinum, platinum-iridium, palladium, palladium alloys, and combinations thereof.