Precision micro-hole for extended life batteries

• US 7,379,555 B2
• Filed: 01/26/2005
• Issued: 05/27/2008
• Est. Priority Date: 06/08/1999
• Status: Expired due to Fees

• Current Assignee: Insound Medical Incorporated (Sonova Holding AG)
• Original Assignee: Insound Medical Incorporated (Sonova Holding AG)
• Inventors: Baker, Ross, O'Hara, Tom, Gable, Richard
• Primary Examiner(s): Ensey; Brian
• Application Number:
  US11/044,993
• Publication Number:
  US 20050259840A1
• Time in Patent Office: 1,217 Days
• Field of Search: 381/312, 381/322, 381/323, 381/324, 429/27, 429/29, 137/625.33
• US Class Current: 381/322
• CPC Class Codes: H01M 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 50/107 having curved cross-section, e.g. round or elliptic H01M50/103, H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 50/119 Metals
• CPC Class Codes: H01M 50/121 Organic material
• CPC Class Codes: H01M 50/124 having a layered structure
• CPC Class Codes: H01M 50/128 with two or more layers of only inorganic material
• CPC Class Codes: H01M 50/129 with two or more layers of only organic material
• CPC Class Codes: H01M 50/14 for protecting against damage caused by external factors
• CPC Class Codes: H04R 2225/61 Aspects relating to mechanical or electronic switches or control elements, e.g. functioning
• CPC Class Codes: H04R 25/602 of batteries
• CPC Class Codes: H04R 25/603 of mechanical or electronic switches or control elements
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Various embodiments of the invention provide an enclosure for a metal-air battery assembly for an extended wear hearing aid. The enclosure includes a diffusion control element having a dimensional property configured for controlling oxygen and moisture diffusion into the metal-air battery assembly to maintain a minimum battery voltage when the hearing aid is operating and worn in an ear canal of a user over an extended period. In an embodiment, the enclosure can comprise a shell with a base end having an opening therein forming a cavity within the shell and a base cap for covering the opening of the base end. A diffusion element is disposed on the base cap. In an embodiment, the diffusion element comprises a laser drilled precision micro hole having an aspect ratio of least about four and a diameter in the range of about 10 to 15 microns.

Claims

1. An enclosure for a metal-air battery assembly for an extended wear hearing aid, the enclosure including a metal shell having at least one hole therethrough and a polymer membrane adjacent the shell for controlling oxygen and moisture diffusion into the metal-air battery assembly to maintain a minimum battery voltage when the hearing aid is operating and worn in an ear canal of a user over an extended period, wherein the polymer membrane has compressed and non-compressed regions with the non-compressed regions aligned with the holes in the shell to control diffusion.

2. The enclosure of claim 1, wherein the shell comprises a base end having an opening therein forming a cavity within the shell and a base cap for covering the opening of the base end.

3. The enclosure of claim 2, wherein a plurality of holes are disposed on the base cap.

4. The enclosure of claim 1, wherein the voltage is in a range from about 1 to 1.3 volts.

5. The enclosure of claim 1, wherein a current drain at which the minimum voltage is maintained is in range from about 40 to 175 μ

A.

6. The enclosure of claim 1, wherein a current drain at which the minimum voltage is maintained is in range from about 40 to 90 μ

A.

7. The enclosure of claim 1, wherein the holes comprise precision micro through-holes.

8. The enclosure of claim 7, wherein at least a portion of the hole is curved, or non-linear.

9. The enclosure of claim 7, wherein the hole is laser drilled.

10. The enclosure of claim 7, wherein the through-hole has a length to diameter ratio such that the gas ingress into the battery assembly is substantially diffusion controlled.

11. The enclosure of claim 7, wherein the through-hole has a length to diameter ratio of at least about 4.

12. The enclosure of claim 7, wherein the precision micro hole has a diameter not greater than about 15 microns.

13. The enclosure of claim 1, where the non-compressed portion has a substantially circular shape.