Method of forming conductive elements

• US 8,763,244 B2
• Filed: 05/26/2009
• Issued: 07/01/2014
• Est. Priority Date: 07/09/2003
• Status: Expired due to Fees

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Schuller, Peter
• Primary Examiner(s): Nguyen, Donghai D
• Application Number:
  US12/472,053
• Publication Number:
  US 20090229739A1
• Time in Patent Office: 1,862 Days
• Field of Search: 298/30, 298/31, 298/46, 298/47, 298/74, 298/84, 298/85, 156/60, 156/155, 156/247, 174/254, 204/290.14, 250/426, 427/540, 600/25, 600/372
• US Class Current: 29/847
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0541 Cochlear electrodes
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0553 Paddle shaped electrodes, e.g. for laminotomy
• CPC Class Codes: H01L 21/4846 Leads on or in insulating or insulated substrates, e.g. metallisation H01L21/4821 takes precedence; metallisation of ceramics in general C04B41/51; printed circuits H05K3/00
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 156/1039 Surface deformation only of sandwich or lamina [e.g., embossed panels]
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49156 with selective destruction of conductive paths
• CPC Class Codes: Y10T 29/49204 Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/53204 Electrode

Abstract

There is disclosed a method of forming a patterned conductive element for an implantable medical device, the method comprising the steps of: depositing a supplementary material on a sheet of conductive, parent material to form a sheet of composite material; applying a carrier material over the supplementary material of the composite sheet to form a sheet of semi-finished material; removing portions from at least the conductive parent material of the sheet of semi-finished material in accordance with a desired pattern corresponding to a patterned conductive element to be formed; and releasing at least the carrier material from the sheet of semi-finished material.

Claims

1. A method of forming an implantable patterned conductive element for an implantable medical device, the method comprising the steps of:

depositing a supplementary material on a sheet of conductive, parent material to form a sheet of composite material;

adhering a carrier material to the supplementary material of the composite sheet to form a second sheet of composite material;

removing portions from at least the sheet of composite material of the second sheet in accordance with a desired pattern corresponding to a patterned conductive element to be formed; and

removing at least the carrier material from the patterned second sheet to form the implantable patterned conductive element.

2. The method according to claim 1, wherein the step of adhering the carrier material comprises co-rolling.

3. The method according to claim 2, wherein the conductive parent material is no greater than 2 mm thick before the co-rolling step.

4. The method according to claim 3, wherein the conductive parent material is no greater than 400 μ

m thick before the co-rolling step.

5. The method according to claim 4, wherein the conductive parent material is no greater than 200 μ

m thick before the co-rolling step.

6. The method according to claim 5, wherein the conductive parent material is no greater than 150 μ

m thick after the co-rolling step.

7. The method according to claim 6, wherein the conductive parent material is no greater than 50 μ

m thick after the co-rolling step.

8. The method according to claim 1, wherein the conductive parent material is biocompatible.

9. The method according to claim 8, wherein the conductive parent material is platinum.

10. The method according to claim 9, wherein the platinum sheet has a thickness being no greater than 100 μ

m.

11. The method according to claim 10, wherein the patterned conductive element is no greater than 1000 μ

m thick.

12. The method according to claim 10, wherein the platinum sheet has a thickness no greater than 200 μ

m.

13. The method according to claim 12, wherein the platinum sheet has a thickness no greater than 40 μ

m.

14. The method according to claim 8, wherein the conductive parent material is platinum/iridium.

15. The method according to claim 1, wherein the supplementary material is selected from any one of the group consisting of TiN, Ta, Nb, Ni and Ir.

16. The method according to claim 1 wherein the carrier material is conductive.

17. The method according to claim 16, wherein the carrier material is copper or steel.

18. The method according to claim 1, wherein the removing portions from at least the sheet of composite material is performed by micro-machining.

19. The method according to claim 18, wherein the micro-machining includes any one selected from the group consisting of EDM, milling and cutting.

20. The method according to claim 1, further comprising the step of coating the patterned parent material with a layer of resiliently flexible material before the removing at least the carrier material.

21. The method according to claim 1, wherein the removing at least the carrier material is by etching.

22. The method according to claim 1, wherein the parent material remaining after the removing at least the carrier material is at least 99.95% pure.

23. The method according to claim 1, wherein the removing portions from at least the sheet of composite material in accordance with a predetermined pattern, the pattern including a linear array of stimulating or recording pads and at least one electrical conduction means extending away from each one of the pads to a location distal from the pad.

24. The method according to claim 23, wherein the electrical conduction means each has an average width of less than 100 μ

m.

25. The method according to claim 24, wherein each stimulating or recording pad has an area of less than 0.5 mm².

26. The method according to claim 25, wherein each electrical conduction means is electrically insulated from its neighbour, the spacing between neighbouring wires being less than 100 μ

m.