Package for an implantable neural stimulation device

• US 8,374,698 B2
• Filed: 08/18/2007
• Issued: 02/12/2013
• Est. Priority Date: 08/18/2006
• Status: Active Grant

• Current Assignee: Cortigent Incorporated
• Original Assignee: Second Sight Medical Products, Inc.
• Inventors: Ok, Jerry, Greenberg, Robert J., Little, James Singleton, Dai, Rongqing, Neysmith, Jordan Matthew, McClure, Kelly H., Talbot, Neil Hamilton
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): KIMBALL, JEREMIAH T
• Application Number:
  US11/893,939
• Publication Number:
  US 20080058895A1
• Time in Patent Office: 2,005 Days
• Field of Search: 607/54, 607/2
• US Class Current: 607/54
• CPC Class Codes: A61F 15/001 Packages or dispensers for bandages, cotton balls, drapes, dressings, gauze, gowns, sheets, sponges, swabsticks or towels A61F15/007 takes precedence
• CPC Class Codes: A61N 1/0529 Electrodes for brain stimulation
• CPC Class Codes: A61N 1/0543 Retinal electrodes
• CPC Class Codes: A61N 1/36046 of the eye
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48106 the connector being orthogonal to a side surface of the semiconductor or solid-state body, e.g. parallel layout
• CPC Class Codes: H01L 2224/48225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 23/055 the leads having a passage through the base H01L23/057 takes precedence
• CPC Class Codes: H01L 23/06 characterised by the material of the container or its electrical properties
• CPC Class Codes: H01L 23/08 the material being an electrical insulator, e.g. glass
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 24/16 of an individual bump connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 25/18 the devices being of types provided for in two or more different subgroups of the same main group of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N
• 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 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

The present invention is an improved hermetic package for implantation in the human body. The implantable device includes an electrically non-conductive substrate with electrically conductive vias. A flip-chip circuit is attached to the substrate using conductive bumps and electrically connected to a first subset of the vias. The flip-chip circuit can contain one or more stacks or a folded stack. A wire-bonded circuit is also attached to the substrate and electrically connected to a second subset of the vias. A cover is bonded to the substrate. The cover, substrate, and vias form an improved hermetic package for implantation.

Claims

1. An implantable device comprising:

an electrically non-conductive substrate;

a plurality of electrically conductive vias through said electrically non-conductive substrate;

a plurality of metal traces on said electrically non-conductive substrate electrically connected to said conductive vias;

a braze stop on said electrically non-conductive substrate and along a periphery of said non-conductive substrate surrounding said plurality of metal traces, and separating a braze joint from said plurality of metal traces;

said electrically non-conductive substrate, said traces, said braze stop trace, and said electrically conductive vias forming a base;

a flip-chip circuit attached directly to said base using conductive bumps;

a second circuit attached directly to said base; and

a cover brazed to said base at said braze joint, said cover, and said base forming a hermetic package;

wherein said flip-chip circuit and said second circuit are adjacent to each other, and mounted to a common substantially planar surface of said base and said braze stop trace prevents said braze from contacting said metal traces.

2. The implantable device according to claim 1, wherein said electrically conductive vias are a metallic and ceramic paste co-fired with said electrically non-conductive substrate to form a hermetic seal.

3. The implantable device according to claim 1, wherein said metal traces are chosen to withstand braze temperatures.

4. The implantable device according to claim 3, wherein said metal traces comprise one or more of the metals titanium, tantalum, gold, palladium, platinum or layers or alloys thereof.

5. The implantable device according to claim 1, further comprising a flexible circuit bump bonded to said base.

6. The implantable device according to claim 5, wherein said flexible circuit is an electrode array suitable for stimulating tissue.

7. The implantable device according to claim 1, further comprising a polymer underfill under said flip-chip circuit.

8. The implantable device according to claim 1, wherein said conductive bumps contain at least one conductive polymer.

9. The implantable device according to claim 1, wherein said conductive bumps contain at least one conductive epoxy or polyimide.

10. The implantable device according to claim 1, wherein said conductive bumps are filled with one or more metals like from the group including silver, platinum, iridium, titanium, platinum alloys, iridium alloys, or titanium alloys or mixtures thereof.

11. The implantable device according to claim 10, wherein said metal or metal alloys are in dust, flake or powder form.

12. The implantable device according to claim 1, wherein said flip chip circuit contains one or two stacks.

13. The implantable device according to claim 1, wherein said flip chip circuit contains three stacks.