Hermetically bonding ceramic and titanium with a Ti-Pd braze interface

• US 7,771,838 B1
• Filed: 09/29/2005
• Issued: 08/10/2010
• Est. Priority Date: 10/12/2004
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: He, Tom Xiaohai, Colvin, Michael S.
• Primary Examiner(s): Austin; Aaron
• Application Number:
  US11/238,603
• Time in Patent Office: 1,776 Days
• Field of Search: 228/262.71, 228/262.72, 228/903
• US Class Current: 428/632
• CPC Class Codes: A61N 1/3605 Implantable neurostimulators for stimulating central or peripheral nerve system
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: B23K 1/19 taking account of the properties of the materials to be soldered
• CPC Class Codes: B23K 2103/14 Titanium or alloys thereof
• CPC Class Codes: B23K 35/0233 Sheets, foils B23K35/0244 takes precedence
• CPC Class Codes: B23K 35/0238 layered
• CPC Class Codes: B23K 35/0244 Powders, particles or spheres; Preforms made therefrom
• CPC Class Codes: B23K 35/322 a Pt-group metal as principal constituent
• CPC Class Codes: B23K 35/325 Ti as the principal constituent
• CPC Class Codes: B32B 15/018 one layer being formed of a noble metal or a noble metal alloy
• CPC Class Codes: C22C 14/00 Alloys based on titanium
• CPC Class Codes: Y10T 428/12611 Oxide-containing component
• CPC Class Codes: Y10T 428/12618 Plural oxides
• CPC Class Codes: Y10T 428/12806 Refractory [Group IVB, VB, or VIB] metal-base component
• CPC Class Codes: Y10T 428/12812 Diverse refractory group metal-base components: alternative to or next to each other
• CPC Class Codes: Y10T 428/12875 Platinum group metal-base component

Abstract

A component assembly for use in living tissue comprises: a ceramic part; a metal part; and a titanium palladium (Ti—Pd) interface layer for bonding said ceramic part to the metal part. In one embodiment, the interface layer may be formed from a single titanium layer in contact with a single palladium layer, or in other embodiments, may be at least a three layer laminate (Pd—Ti—Pd). A microstimulator housing comprising a ceramic part, a titanium or titanium alloy part sandwiching the Ti—Pd interlayer may be employed to create a eutectic bond that is strong and hermetic.

Claims

1. A component assembly for use in living tissue comprising:

a ceramic part;

a metal part selected from the group consisting of titanium and titanium alloys; and

an interface layer consisting essentially of titanium and palladium, the interface layer bonding the ceramic part to the metal part.

2. The component assembly of claim 1, wherein said ceramic part is selected from the group consisting or zirconia, stabilized zirconia, partially stabilized zirconia, tetragonal zirconia, magnesia stabilized zirconia, ceria-stabilized zirconia, yttria-stabilized zirconia, and calcia-stabilized zirconia, as well as alumina, and titania.

3. The component assembly of claim 1, wherein the interface layer forms a eutectic bond between said metal part and said ceramic part.

4. The component assembly of claim 1, wherein the interface layer can be heated to a temperature that is at or greater than the eutectic melting point of the interface layer.

5. The component assembly of claim 1, wherein the interface layer is a three-layer laminate comprising two palladium layers at least partially covering opposing sides of a titanium layer.

6. The component assembly of claim 5, wherein the laminate is cold rolled to provide the intimate contact between layers.

7. The component assembly of claim 1, wherein the interface layer is a two-layer laminate of comprising a titanium layer and a palladium layer.

8. The component assembly of claim 7, wherein the laminate is cold rolled to provide intimate contact between layers.

9. The component assembly of claim 7, wherein the laminate is formed by sputter coating palladium over titanium.

10. The component assembly of claim 7, wherein the laminate is formed by vapor deposition of palladium over titanium.

11. A microstimulator comprising:

a component assembly housing comprising;

a ceramic part;

a metal part selected from the group consisting of titanium and titanium alloy; and

an interface layer consisting essentially of titanium and palladium, the interface layer bonding the ceramic part to the metal part.

12. The microstimulator of claim 11, wherein said ceramic part is selected from the group consisting of zirconia, stabilized zirconia, partially stabilized zirconia, tetragonal zirconia, magnesia stabilized zirconia, ceria-stabilized zirconia, yttria-stabilized zirconia, and calcia-stabilized zirconia, as well as alumina, and titania.

13. The microstimulator of claim 11, wherein the interface layer forms a eutectic bond between said metal part and said ceramic part.

14. The microstimulator of claim 11, wherein the interface layer can be heated to a temperature that is at or greater than the eutectic melting point of the interface layer.

15. The microstimulator of claim 11, wherein the interface layer is a three-layer laminate comprising two palladium layers at least partially covering opposing sides of a titanium layer.

16. The microstimulator of claim 15, wherein the laminate is cold rolled to provide intimate contact between layers.

17. The microstimulator of claim 11, wherein the interface layer is a two-layer laminate comprising a titanium layer and a palladium layer.

18. The microstimulator of claim 17, wherein the laminate is cold rolled to provide intimate contact between layers.

19. The microstimulator of claim 17, wherein the laminate is formed by sputter coating palladium over titanium.

20. The microstimulator of claim 17, wherein the laminate is formed by vapor deposition of palladium over titanium.