Method of inspection of materials for defects

• US 8,131,376 B1
• Filed: 09/11/2008
• Issued: 03/06/2012
• Est. Priority Date: 09/11/2007
• Status: Active Grant

• Current Assignee: Cortigent Incorporated
• Original Assignee: Second Sight Medical Products, Inc.
• Inventors: Faraji, Boozarjomehr, Talbot, Neil Hamilton, Little, James Singleton, Greenberg, Robert J., Ha, Kevin Jun
• Primary Examiner(s): Manuel, George
• Assistant Examiner(s): Wieland, Robert
• Application Number:
  US12/209,068
• Time in Patent Office: 1,272 Days
• Field of Search: 607/32, 607/36, 607/54, 600/459, 736/02, 736/19
• US Class Current: 607/54
• CPC Class Codes: A61N 1/0526 Head electrodes A61N1/0551 takes precedence
• CPC Class Codes: A61N 1/0543 Retinal electrodes
• CPC Class Codes: A61N 1/36046 of the eye
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation
• CPC Class Codes: G01N 29/00 Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object G01N3/00, G01N5/00, G01N7/00, G01N9/00, G01N11/00, G01N13/00, G01N15/00, G01N17/00, G01N19/00, G01N21/00, G01N22/00, G01N23/00, G01N24/00, G01N25/00, G01N27/00 take precedence
• CPC Class Codes: G01N 29/26 Arrangements for orientation or scanning by relative movement of the head and the sensor mechanical steering of sound transducers or their beams G10K11/35

Abstract

The present invention is a non-destructive method of inspecting a bond, particularly a braze bond, in a hermetic package. The invention involves a unique hermetic package design adapted for ultrasonic inspection and a method of inspecting the package. This package and non-destructive inspection process are particularly useful in implantable neural stimulators such as visual prostheses.

Claims

1. A method of inspecting a bond in a hermetic package comprising:

providing a hermetic package comprising;

a bottom having an inside surface, an outside surface and a side surface,

a top having a first lip in contact with said side surface,

a bond attaching said top to said inside surface, wherein said bond is parallel to and less than 500 μ

m from said outside surface;

scanning said hermetic package with acoustic energy;

receiving reflected acoustic energy from said step of scanning; and

determining the quality of said bond from said reflected acoustic energy.

2. The method of inspecting a bond according to claim 1, wherein said acoustic energy is ultrasonic energy.

3. The method of inspecting a bond according to claim 1, wherein said step of scanning is scanning with acoustic micro imaging.

4. The method of inspecting a bond according to claim 1, wherein said step of scanning is scanning with scanning acoustic microscopy.

5. The method of inspecting a bond according to claim 1, wherein said bond is selected from the group consisting of a braze bond and a solder bond.

6. The method of inspecting a bond according to claim 1, wherein said top and said bottom are optically opaque.

7. The method of inspecting a bond according to claim 1, wherein said top and said bottom are selected from the group consisting of a metal and a ceramic.

8. The method of inspecting a bond according to claim 1, wherein said reflected acoustic energy identifies gaps in said bond.

9. The method of inspecting a bond according to claim 1, wherein said reflected acoustic energy identifies delaminations of said bond.

10. The hermetic package according to claim 1,

wherein said top comprises a lid portion and a middle portion, the lid portion having a second lip in contact with an inner surface of the middle portion.

11. A hermetic package comprising:

a top having a first lip;

a bottom having an outside surface, an inside surface and a side surface;

a bond attaching said top to said inside surface,

wherein said bond is parallel to said outside surface and is less than 500 μ

m from said outside surface to allow for acoustic imaging; and

wherein said first lip is in contact with said side surface.

12. The hermetic package according to claim 11, wherein said bond is selected from the group consisting of a braze bond and a solder bond.

13. The hermetic package according to claim 11, wherein said top and said bottom are selected from the group consisting of a metal and a ceramic.

14. The hermetic package according to claim 11, wherein said hermetic package is biocompatible.

15. The hermetic package according to claim 14, wherein said hermetic package is suitable for implantation within a human body as a neural stimulator.

16. The hermetic package according to claim 15, wherein said hermetic package is suitable for implantation within a human body as a visual prosthesis.

17. The hermetic package according to claim 11,

wherein said top comprises a lid portion and a middle portion, the lid portion having a second lip in contact with an inner surface of the middle portion.

18. A visual prosthesis comprising a hermetic package enclosing an electronic circuit and an array of electrodes driven by said electronic circuit suitable to stimulate visual neurons,

wherein said hermetic package comprises:

a bottom having an inside surface, an outside surface and a side surface;

a top having a first lip in contact with said side surface;

a bond attaching said top to said inside surface, wherein said bond is parallel to said outside surface, wherein a distance between said bond and said outside surface is configured to allow for acoustic imaging of said bond.

19. The visual prosthesis according to claim 18, wherein said bottom has a thickness of less than 500 μ

m to allow for acoustic imaging of said bond.

20. The visual prosthesis according to claim 18,

wherein said top comprises a lid portion and a middle portion, the lid portion having a second lip in contact with an inner surface of the middle portion.