Self-centering braze assembly

• US 20040058186A1
• Filed: 06/27/2003
• Published: 03/25/2004
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Advanced Bionics Corporation (Sonova Holding AG)
• Inventors: Daulton, Jay
• Granted Patent: US 7,132,173 B2
• Time in Patent Office: Days
• US Class Current: 428/621
• CPC Class Codes: A61N 1/36007 of urogenital or gastrointestinal organs, e.g. for incontinence control
• 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 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/37235 Aspects of the external programmer
• CPC Class Codes: A61N 1/3727 characterised by the modulation technique
• CPC Class Codes: A61N 1/37276 characterised by means for reducing power consumption during telemetry
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00011 Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/1461 : MEMS
• CPC Class Codes: H01L 2924/19105 : in a side-by-side arrangement on a common die mounting substrate
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/30111 : matching
• CPC Class Codes: H02J 2310/23 : The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/10 : using inductive coupling
• CPC Class Codes: H02J 7/345 : using capacitors as storage or buffering devices
• CPC Class Codes: H04B 5/26 : using coils
• CPC Class Codes: H04B 5/79 : for data transfer in combination with power transfer
• CPC Class Codes: H04L 27/02 : Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence
• CPC Class Codes: H04L 27/10 : Frequency-modulated carrier systems, i.e. using frequency-shift keying H04L27/32 takes precedence
• CPC Class Codes: Y10T 29/4902 : Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49071 : by winding or coiling
• CPC Class Codes: Y10T 29/49073 : by assembling coil and core
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49169 : Assembling electrical component directly to terminal or elongated conductor
• CPC Class Codes: Y10T 29/49826 : Assembling or joining
• CPC Class Codes: Y10T 29/49945 : by driven force fit
• CPC Class Codes: Y10T 29/49968 : Metal fusion joining
• CPC Class Codes: Y10T 428/12264 : having outward flange, gripping means or interlocking feature
• CPC Class Codes: Y10T 428/12271 : having discrete fastener, marginal fastening, taper, or end structure
• CPC Class Codes: Y10T 428/12347 : Plural layers discontinuously bonded [e.g., spot-weld, mechanical fastener, etc.]
• CPC Class Codes: Y10T 428/12375 : having member which crosses the plane of another member [e.g., T or X cross section, etc.]
• CPC Class Codes: Y10T 428/12396 : Discontinuous surface component
• CPC Class Codes: Y10T 428/12535 : with additional, spatially distinct nonmetal component
• CPC Class Codes: Y10T 428/12806 : Refractory [Group IVB, VB, or VIB] metal-base component

Abstract

Braze and electrode wire assemblies, e.g., used with an implantable microstimulator, include a wire welded in the through-hole of an electrode, which electrode is brazed to a ceramic case that is brazed to a metal ring that is welded to a metal can. The braze joints are step or similar joints that self-center the case, provide lateral support during braze assembly, and provide increased surface area that prevents braze material from exuding from the joints. The end of the ceramic case that is brazed to the metal ring need not be specially machined. The shell has a reference electrode on one end and an active electrode on the other, and is externally coated on selected areas with conductive and non-conductive materials.

Claims

1. A braze assembly, comprising:

a metal member including an exterior flange of the metal member, the exterior flange including an inner surface;

a braze material including titanium and nickel; and

a ceramic member including a formed end, wherein the formed end of the ceramic member adjoins the inner surface of the exterior flange and is brazed to metal member with the braze material.

2. The braze assembly of claim 1 wherein the braze assembly is used to hermetically seal the shell of a microstimulator.

3. The braze assembly of claim 1 wherein the ceramic member is a substantially close-ended ceramic can and the metal member forms an end cap to the ceramic member, which end cap completely closes the end of the ceramic can.

4. The braze assembly of claim 3 wherein the end cap is an electrode.

5. The braze assembly of claim 4 wherein the electrode further comprises:

a narrow-diameter pin;

a broad-diameter braze surface adjoining the substantially closed-end of the ceramic member; and

a stimulating surface with grooves that increase the surface area of the stimulating surface.

6. The braze assembly of claim 1 wherein the exterior flange forms a step at the end of the metal member against which the formed end of the ceramic member may be received, and wherein the surface area between the metal member and the ceramic member is capable of receiving an adequate amount of braze material to form a strong braze bond.

7. The braze assembly of claim 6 wherein the exterior flange provides lateral support to the braze assembly.

8. A braze assembly for a microstimulator, comprising:

a metal member including an exterior flange of the metal member, the exterior flange including an inner surface;

a braze material including titanium and nickel; and

a ceramic member including a formed end, wherein the formed end of the ceramic member adjoins the inner surface of the exterior flange and is brazed to metal member with the braze material;

wherein the metal member, the braze material, and the ceramic member form a braze assembly that is used to hermetically seal a microstimulator shell.

9. The braze assembly of claim 8 wherein the ceramic member is a substantially close-ended ceramic can and the metal member forms an end cap to the ceramic member, which end cap completely closes the end of the ceramic can.

10. The braze assembly of claim 9 wherein the end cap is an electrode.

11. The braze assembly of claim 10 wherein the electrode further comprises:

a narrow-diameter pin;

a broad-diameter braze surface adjoining the substantially closed-end of the ceramic member; and

a stimulating surface with grooves that increase the surface area of the stimulating surface.

12. The braze assembly of claim 8 wherein the exterior flange forms a step at the end of the metal member against which the formed end of the ceramic member may be received, and wherein the surface area between the metal member and the ceramic member is capable of receiving an adequate amount of braze material to form a strong braze bond.

13. The braze assembly of claim 12 wherein the exterior flange provides lateral support to the braze assembly.

14. A method of brazing an assembly, comprising:

providing a ceramic member with an end, which end is formed without machining and which ceramic member includes zirconia;

placing braze material between a metal member and the ceramic member, the braze material including titanium and nickel, the metal member including titanium and an exterior flange, which exterior flange includes an inner surface;

compressing the metal member and the end of the ceramic member formed without machining together;

heating the braze material, the metal member, and the ceramic member in a vacuum until the braze material forms a liquidus; and

cooling the braze material, the metal member, and the ceramic member in the vacuum until the braze material forms a solidus.

15. The method of claim 14 wherein the ceramic member includes a substantially closed end.

16. The method of claim 15, wherein the step of placing the braze material between the metal member and the ceramic member further comprises the step of aligning the metal member with the braze material and the substantially closed end of the ceramic member.

17. The method of claim 14 wherein the end cap is an electrode.

18. The method of claim 17 wherein the electrode further comprises:

a narrow-diameter pin;

a broad-diameter braze surface adjoining the substantially closed-end of the ceramic member; and

a stimulating surface with grooves that increase the surface area of the stimulating surface.

19. The method of claim 14 further comprising the following steps:

receiving the ceramic member into the exterior flange of the metal member before the steps of compressing, heating, and cooling; and

the step of placing further including placing an amount of braze material between the metal member and the ceramic member, which amount of braze material is capable of forming a strong braze bond without exuding from between the metal member and the ceramic member.

20. The method of claim 19 wherein the exterior flange provides lateral support to ceramic member during the steps of compressing, heating, and cooling.