Method for manufacturing a stent

• US 5,902,475 A
• Filed: 04/08/1997
• Issued: 05/11/1999
• Est. Priority Date: 04/08/1997
• Status: Expired due to Term

• Current Assignee: Interventional Technologies Incorporated (Boston Scientific Corporation)
• Original Assignee: Interventional Technologies Incorporated (Boston Scientific Corporation)
• Inventors: Gomringer, Gary W., Trozera, Thomas
• Primary Examiner(s): Gorgos, Kathryn
• Assistant Examiner(s): Parsons, Thomas H
• Application Number:
  US08/835,015
• Time in Patent Office: 763 Days
• Field of Search: 205/151, 205/209, 205/210, 205/212, 205/218, 205/221, 205/223, 205/224, 205/229, 205/655
• US Class Current: 205/655
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/3011 Cross-sections or two-dimensional shapes
• CPC Class Codes: A61F 2002/30156 triangular
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2230/0002 Two-dimensional shapes, e.g. cross-sections
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0023 triangular
• CPC Class Codes: A61F 2230/0026 trapezoidal
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: G03B 27/04 Copying apparatus without a relative movement between the original and the light source during exposure, e.g. printing frame or printing box
• CPC Class Codes: G03F 7/00 Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor using photoresist structures for special production processes, see the relevant places, e.g. B44C, H01L, e.g. H01L21/00, H05K
• CPC Class Codes: G03F 7/18 Coating curved surfaces

Abstract

Disclosed herewithin is a method of fabricating a stent which involves processing a tubular member whereby no connection points to join the edges of a flat pattern are necessary. The method includes the steps of a) removing contaminates from a tubular member, b) coating the outside surface of the tubular member with a photo-sensitive resist material, c) placing the tubular member in an apparatus designed to simultaneously rotate the tubular member while passing a specially configured photographic frame negative between a UV light source and the tubular member, thereby exposing a specified pattern of UV light to the resist coated tubular member, d) exposing the outside surface of the tubular member to a photoresist developer for a specified period of time, e) rinsing the excess developer and uncured resist from the outside surface of the tubular member, f) treating the tubular member with a electro-chemical process to remove uncovered metal. This process can lend itself to virtually an unlimited number of stent designs and configurations. By modifying the photographic frame negative, the same process can be employed to fabricate various stent designs from a tubular structure.

Claims

1. A stent fabrication method comprising the steps of:

(a) Coating an outer surface of a metallic tubular member with a photo-sensitive resist resulting in a coated tubular member;

(b) Placing said coated tubular member in an apparatus which simultaneously exposes a selected portion and shields other selected portions of said outer surface of said coated tubular member to a light source, yielding a partially exposed tubular member;

(c) Immersing said partially exposed tubular member in a negative resist developer resulting in a treated tubular member;

(d) Processing said treated tubular member by electro-chemical etching process to remove metal located in said selected portions of said tubular member shielded from said light source.

2. A stent fabrication method as recited in claim 1, further comprising the step of cleaning said tubular member prior to the step of coating said outer surface of said metallic tubular member with said photo-sensitive resist.

3. A stent fabrication method as recited in claim 1, further comprising the step of coating said outer surface of said tubular member with a coupling agent prior to the step of coating said outer surface of said metallic tubular member with said photo-sensitive resist.

4. A stent fabrication method as recited in claim 1, further comprising the step of incubating said treated tubular member in a temperature range, said temperature range being between 100 and 400 degrees Celsius, after the step of immersing said partially exposed tubular member to said negative resist developer.

5. A stent fabrication method as recited in claim 1, wherein said exposure of said light source to portions of said coated tubular member is regulated by a pattern imprinted on photographic film.

6. A stent fabrication method as recited in claim 2, further comprising the step of heating said tubular member in a temperature range, said temperature range being between 100 and 200 degrees Celsius, after the step of cleaning the tubular member.

7. A stent fabrication method as recited in claim 1, wherein said light source has a wavelength within the range of 360 to 440 nanometers.

8. A stent fabrication method as recited in claim 1, wherein said light source has a preferred wavelength optimized for the specific photoresist employed.

9. A stent fabrication method as recited in claim 3, wherein said coupling agent comprises a class of organo-silane compounds.

10. A stent fabrication method as recited claim 1, wherein a plurality of stents are made from a single piece of tubing.

11. A stent fabrication method as recited in claim 1, wherein said tubular member is made from a material selected from the group consisting of polymers, stainless steel, titanium, platinum, gold alloys, gold/platinum alloys and tantalum.

12. A stent fabrication method as recited in claim 1, wherein said electro-chemical etching process employs a solution of phosphoric acid and sulfuric acid.

13. A stent fabrication method as recited in claim 1, wherein said electro-chemical etching process employs a solution of ferric chloride.

14. A stent fabrication method as recited in claim 1, wherein said electro-chemical etching process employs a solution of potassium cyanide.

15. A stent fabrication method as recited in claim 1, wherein said electro-chemical etching process employs a solution sodium of hypochlorite.

16. A stent fabrication method as recited in claim 1, wherein said electro-chemical etching process employs a solution of hydrochloric acid and nitric acid.

17. A stent fabrication method comprising the steps of:

(a) Coating an outer surface of a metallic tubular member with a photo-sensitive resist resulting in a coated tubular member;

(b) Placing said coated tubular member in an apparatus which simultaneously rotates said coated tubular member in conjunction with an advancing photographic film which regulates the exposure of a selected portion and shields other selected portions of said outer surface of said coated tubular member to a light source, yielding a partially exposed tubular member;

(c) Immersing said partially exposed tubular member in a negative resist developer resulting in a treated tubular member;

(d) Processing the treated tubular member by chemical etching to remove a portion of uncovered metal.

18. A stent fabrication method as recited in claim 17, further comprising the step of cleaning said tubular member prior to the step of coating said outer surface of said metallic tubular member with said photo-sensitive resist.

19. A stent fabrication method as recited in claim 17, further comprising the step of coating said outer surface of said tubular member with a coupling agent prior to the step of coating said outer surface of said metallic tubular member with said photo-sensitive resist material.

20. A stent fabrication method as recited in claim 17, further comprising the step of incubating said treated tubular member in a temperature range, said temperature range being between 100 and 400 degrees Celsius, after the step of immersing said partially exposed tubular member to the negative resist developer.

21. A stent fabrication method as recited in claim 17, wherein said exposure of light source to portions of the stent is regulated by a stent configuration on transparent photographic film.

22. A stent fabrication method as recited in claim 18, further comprising the step of heating said tubular member in a temperature range, said temperature range being between 100 and 200 degrees Celsius, after the step of cleaning the tubular member.

23. A stent fabrication method as recited in claim 17, wherein said light source has a wavelength within the range of 360 to 440 nanometers.

24. A stent fabrication method as recited in claim 17, wherein said light source has a preferred wavelength optimized for the specific photoresist employed.

25. A stent fabrication method as recited in claim 19, wherein said coupling agent comprises a class of organo-silane compounds.

26. A stent fabrication method as recited claim 17, wherein a plurality of stents are made from a single piece of tubing.

27. A stent fabrication method as recited in claim 17, wherein said tubular member is made from a material selected from the group consisting of polymers, stainless steel, titanium, platinum, gold alloys, gold/platinum alloys and tantalum.

28. A stent fabrication method as recited in claim 17, wherein said electro-chemical etching process employs a solution of phosphoric acid and sulfuric acid.

29. A stent fabrication method as recited in claim 17, wherein said electro-chemical etching process employs a solution of ferric chloride.

30. A stent fabrication method as recited in claim 17, wherein said electro-chemical etching process employs a solution of potassium cyanide.

31. A stent fabrication method as recited in claim 17, wherein said electro-chemical etching process employs a solution of sodium hypochlorite.

32. A stent fabrication method as recited in claim 17, wherein said electro-chemical etching process employs a solution of hydrochloric acid and nitric acid.

33. A stent fabrication method comprising the steps of:

(a) Coating an outer surface of a metallic tubular member with a protective polymeric coating resulting in a coated tubular member;

(b) Placing said coated tubular member in an apparatus which simultaneously exposes a selected portion and shields other selected portions of said outer surface of said coated tubular member to a light source, resulting in some polymeric coating exposed and some polymeric coating unexposed, yielding a partially exposed tubular member;

(c) Immersing said partially exposed tubular member in a solvent for selectively removing unexposed polymeric coating resulting in a treated tubular member;

(d) Processing said treated tubular member by electro-chemical etching process to remove metal located in said selected portions of said tubular member shielded from said light source.

34. A stent fabrication method as recited in claim 33, wherein said protective polymeric coating comprises a class of photo-sensitive resists.

35. A stent fabrication method as recited in claim 33, wherein said solvent for selectively removing unexposed polymeric coating comprises a class of negative resist developers.

36. A stent fabrication method as recited in claim 33, further comprising the step of cleaning said tubular member prior to the step of coating said outer surface of said metallic tubular member with said protective polymeric coating.

37. A stent fabrication method as recited in claim 33, further comprising the step of coating said outer surface of said tubular member with a coupling agent prior to the step of coating said outer surface of said metallic tubular member with said protective polymeric coating.

38. A stent fabrication method as recited in claim 33, further comprising the step of incubating said treated tubular member in a temperature range, said temperature range being between 100 and 400 degrees Celsius, after the step of immersing said partially exposed tubular member to said solvent for selectively removing unexposed polymeric coating.

39. A stent fabrication method as recited in claim 33, wherein said exposure of said light source to portions of said coated tubular member is regulated by a pattern imprinted on photographic film.

40. A stent fabrication method as recited in claim 36, further comprising the step of heating said tubular member in a temperature range, said temperature range being between 100 and 200 degrees Celsius, after the step of cleaning the tubular member.

41. A stent fabrication method as recited in claim 33, wherein said light source has a wavelength within the range of 360 to 440 nanometers with a preferred wavelength of 390 nanometers.

42. A stent fabrication method as recited in claim 33, wherein said light source has a preferred wavelength optimized for the specific photoresist employed.

43. A stent fabrication method as recited in claim 37, wherein said coupling agent comprises a class of organo-silane compounds.

44. A stent fabrication method as recited claim 33, wherein a plurality of stents are made from a single piece of tubing.

45. A stent fabrication method as recited in claim 33, wherein said tubular member is made from a material selected from the group consisting of polymers, stainless steel, titanium, platinum, gold alloys, gold/platinum alloys and tantalum.

46. A stent fabrication method as recited in claim 33, wherein said electro-chemical etching process employs a solution of phosphoric acid and sulfuric acid.

47. A stent fabrication method as recited in claim 33, wherein said electro-chemical etching process employs a solution of ferric chloride.

48. A stent fabrication method as recited in claim 33, wherein said electro-chemical etching process employs a solution of potassium cyanide.

49. A stent fabrication method as recited in claim 33, wherein said electro-chemical etching process employs a solution of sodium hypochloride.

50. A stent fabrication method as recited in claim 33, wherein said electro-chemical etching process employs a solution of hydrochloric acid and nitric acid.