CONDUCTIVE ELEMENTS

• US 20090229739A1
• Filed: 05/26/2009
• Published: 09/17/2009
• Est. Priority Date: 07/09/2003
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: SCHULLER, Peter
• Granted Patent: US 8,763,244 B2
• Time in Patent Office: Days
• US Class Current: 156/154
• 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 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.

2. The method according to claim 1, wherein the step of applying the carrier material to form the sheet of semi-finished material comprises co-rolling.

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

4. The method according to claim 3, wherein the conductive parent material is platinum.

5. The method according to claim 3, wherein the conductive parent material is platinum/iridium.

6. The method according to claim 1, wherein the conductive parent material of the sheet of semi-finished material is no greater than 2 mm thick before the co-rolling step.

7. The method according to claim 6, wherein the conductive parent material of the sheet of semi-finished material is no greater than 400 μ

m thick before the co-rolling step.

8. The method according to claim 7, wherein the conductive parent material of the sheet of semi-finished material is no greater than 200 μ

m thick before the co-rolling step.

9. The method according to claim 8, wherein the conductive parent material of the sheet of semi-finished material is no greater than 150 μ

m thick after the co-rolling step.

10. The method according to claim 9, wherein the conductive parent material of the sheet of semi-finished material is no greater than 50 μ

m thick after the co-rolling step.

11. 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.

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

13. The method according to claim 12, wherein the carrier material is copper or steel.

14. The method according to claim 1, wherein the removing step is performed by micro-machining.

15. The method according to claim 14, wherein the micromachining includes any one selected from the group consisting of EDM, milling and cutting.

16. 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 releasing step.

17. The method according to claim 1, wherein the releasing step is by dissolution.

18. The method according to claim 1, wherein the patterned element of parent material after the releasing step, is at least 99.95% pure.

23. The method according to claim 17, wherein the supplementary material is any one selected from the group consisting of TiN, Ta, Nb and Ir.

24. The method according to claim 17, wherein the carrier material is conductive.

26. The method according to claim 17, wherein the platinum sheet on the semi-finished material is at least 99.95% pure.

19. A method of making a sheet of semi-finished material, the method comprising the steps of:

depositing a supplementary material on a platinum sheet to form a composite sheet; and

applying a carrier material over the supplementary material, to form a sheet of semi-finished material;

wherein the platinum sheet on the sheet of semi-finished material has a thickness being no greater than 100 μ

m.

20. The method according to claim 19, wherein the platinum sheet on the semi-finished material has a thickness no greater than 40 μ

m

21. The method according to claim 19, wherein the semi-finished material is no greater than 1000 μ

m thick.

22. The method according to claim 19, wherein the semi-finished material is no greater than 200 μ

m thick.

25. The method according to claim 22, wherein the carrier material is copper or steel.

27. A method of forming an electrode array for an implantable medical device, the method comprising the steps of:

preparing a semi-finished sheet by depositing a supplementary material on a platinum sheet and then applying a carrier material over the supplementary material;

removing portions from at least the platinum sheet 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; and

releasing the carrier material.

28. The method according to claim 27, wherein the electrical conduction means each have an average width of less than 100 μ

m.

29. The method according to claim 28, wherein each stimulating or recording pad has an area of less than 0.5 mm2.

30. The method according to claim 29, wherein each electrical conduction means is electrically insulated from its neighbour, the spacing between neighbouring wires being less than 100 μ

m.

31. The method according to claim 30, further comprising the step of coating the platinum sheet with a layer of resiliently flexible material before the releasing step.

32. The method according to claim 31, wherein the step of applying the carrier material comprises co-rolling.

33. The method according to claim 32, wherein the supplementary material is any one selected from the group consisting of TiN, Ta, Nb, Ni and Ir.

34. The method according to claim 33, wherein the carrier material is conductive.

35. The method according to claim 34, wherein the carrier material is copper or steel.

36. The method according to claim 35, wherein the removing step is performed by any one selected from the group consisting of EDM, milling and cutting.

37. The method according to claim 36, wherein the releasing step is by dissolution.

38. The method according to claim 37, wherein the platinum sheet is at least 99.95% pure.