JP6567343B2 - Manufacturing method of medical device - Google Patents

Description

  The present invention relates to a method for manufacturing a medical device.

  An example of a medical device is a stent. A stent is a medical device that expands a tubular portion (blood vessel, trachea, esophagus, duodenum, large intestine, biliary tract, etc.) from the inside of a lumen. As an example of the stent, there is a cylindrical tube made of metal, and a stent corresponding to a site to be treated is used. Stent graft endoscopy is performed as a treatment for angina pectoris, acute myocardial infarction, acute coronary syndrome, blood vessels due to cancer, trachea, esophagus, duodenum, large intestine, biliary stricture, and cerebral infarction.

A conventional method for manufacturing a stent is as follows.
A single metal or alloy pipe made of medical stainless steel (SUS316L, SUS316LVN), cobalt chromium, NiTi or the like is processed by laser light from the outer periphery, and then the stent is processed through heat treatment, acid cleaning, and electropolishing. Produced. The acid cleaning and electropolishing processes are processes in which burrs are generated at the cut surface during laser processing, and thus the burrs are removed to finish the stent surface smoothly.

  In the conventional stent manufacturing method, the pipe of the material itself is overheated during laser processing, causing segregation of impurities and the like on the surface of the pipe, and part of the mesh of the stent may be disconnected during the acid cleaning process. .

  In addition, when attempting to manufacture a long stent having a longitudinal direction of, for example, 100 mm or more, there is a problem that when the stent is cooled after laser processing, the processing accuracy required for dripping due to the weight of the stent cannot be maintained. Therefore, the length of the stent that can maintain the required processing accuracy is limited to about 30 to 40 mm, and the processing accuracy cannot be improved with a stent longer than that, so the conventional method for manufacturing a stent corresponds to a long stent. There is a problem that can not be.

  That is, in the stent manufacturing method using laser processing, there is a problem that processing accuracy is lowered by heat applied to the stent during laser processing.

JP 2014-36817 A

  An object of one embodiment of the present invention is to provide a method for manufacturing a medical device that can suppress a decrease in processing accuracy due to heat such as laser processing.

Hereinafter, various aspects of the present invention will be described.
[1] A step of forming a mask film having an opening pattern on a sacrificial material;
Forming a groove pattern in the sacrificial material by etching so as not to penetrate the sacrificial material using the mask film as a mask;
Forming a film on the mask film;
Etching the mask film to separate the film from the mask film;
A method for manufacturing a medical device, comprising:

[1-1] In the above [1],
The groove pattern has a portion where the sacrificial material is etched immediately below the mask film around the hole pattern;
A method of manufacturing a medical device, wherein a gap is formed in the etched portion in the step of forming the film.

[2] In the above [1] or [1-1],
The step of forming the mask film is a step of forming a mask film having a hole pattern on an outer surface of the sacrificial tube, wherein the sacrificial material is a sacrificial tube,
The process of separating the film is a process of forming a tubular object made of the film by separating the film from the mask film.

[2-1] In the above [2],
The step of forming the mask film includes forming a mask film on an outer surface of the sacrificial tube, forming a photoresist film on the mask film, exposing the photoresist film, and developing the mask film. Forming a resist pattern thereon, etching the mask film using the resist pattern as a mask to form a mask film having an opening pattern on the outer surface of the sacrificial tube, and peeling the resist pattern The manufacturing method of the medical device characterized by including a process.

[2-2] In the above [2] or [2-1],
The groove pattern has a portion where the sacrificial tube is etched immediately below the mask film around the hole pattern;
A method of manufacturing a medical device, wherein a gap is formed in the etched portion in the step of forming the film.

[3] In any one of the above [2], [2-1] and [2-2],
The method of manufacturing a medical device is characterized in that the step of forming the film is a step of forming a film on the mask film while rotating the sacrificial tube.

[4] In any one of [2], [2-1], [2-2] and [3] above,
The method of manufacturing a medical device, wherein the sacrificial tube has a branched tube shape or a tube shape having different end diameters.

[5] In any one of the above [1], [1-1], [2], [2-1], [2-2], [3] and [4],
The method of forming a film is a process of forming a film on the mask film while heating the sacrificial material.

[6] In any one of the above [1], [1-1], [2], [2-1], [2-2], [3], [4] and [5],
The method for forming a film is a method for forming a film on the mask film by vapor deposition, thermal spraying, CVD, or sputtering.

[7] Any one of [1], [1-1], [2], [2-1], [2-2], [3], [4], [5], and [6] In
The membrane is a membrane made of one material selected from the group of stainless steel, CoCr alloy, titanium alloy, superelastic biometric shape memory alloy, nylon, polypropylene, polydioxanone, and polylactic acid. A method of manufacturing a medical device.

  According to one embodiment of the present invention, it is possible to provide a method for manufacturing a medical device that can suppress a decrease in processing accuracy due to heat such as laser processing.

(A)-(E) are sectional drawings for demonstrating the manufacturing method of the medical device which concerns on 1 aspect of this invention. (A)-(E) are sectional drawings for demonstrating the manufacturing method of the medical device which concerns on 1 aspect of this invention. (A) is sectional drawing which shows the sacrificial pipe from which the diameter of an edge part differs, (B) is sectional drawing which shows the sacrificial pipe branched in branch shape.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

[First Embodiment]
1A to 1E are cross-sectional views illustrating a method for manufacturing a medical device according to one embodiment of the present invention.

  First, as shown in FIG. 1A, a sacrificial material 11 is prepared. The material of the sacrificial material 11 is preferably a metal, but Cu is used in the present embodiment. The shape of the sacrificial material 11 is, for example, a plate shape.

  Next, a plating film (electroformed film) 12 is formed on the sacrificial material 11 by electrolytic plating. That is, the plating film 12 is formed on the sacrificial material 11 by flowing a plating solution (electroforming solution) through the sacrificial tube 11 and passing an electric current through the sacrificial material 11. In FIG. 1, the plating film 12 is not formed on the lower surface of the sacrificial material 11, but the plating film 12 may be formed on the upper surface and the lower surface of the sacrificial material 11. The thickness of the plating film 12 is, for example, not less than 0.02 mm and not more than 0.5 mm. The plating film 12 is a Ni film, for example.

  Next, as shown in FIG. 1B, a metal mask (mask film) 12 b having an opening pattern 12 a is formed on the sacrificial material 11 by processing the plating film 12. Specifically, a photoresist film (not shown) is formed on the plating film 12, and the photoresist film is exposed and developed to form a resist pattern on the plating film 12. By etching the plating film 12 using this resist pattern as a mask, a metal mask 12 b having an opening pattern 12 a is formed on the sacrificial material 11. Next, the resist pattern is peeled off.

  Thereafter, as shown in FIG. 1C, the sacrificial material 11 is half-etched using the metal mask 12b as a mask, thereby forming a groove pattern 11a to which the opening pattern 12a is transferred in the sacrificial material 11. The groove pattern 11a has an undercut portion 11b, which is a portion where the sacrificial material 11 located immediately below the metal mask 12b around the hole pattern 12a is etched. In order to form the undercut portion 11b, the above half etching is preferably isotropic etching, for example, wet etching or isotropic dry etching is preferably used.

  In this embodiment, the sacrificial material 11 is etched to about half the depth of the sacrificial material 11 by half-etching. However, the present invention is not limited to this, and etching is performed so as not to penetrate the sacrificial material 11. It is also possible to etch to various depths as long as it is.

  Thereafter, as shown in FIG. 1D, a material film 13 for a medical device is formed on the metal mask 12b and in the groove pattern 11a by vapor deposition, thermal spraying, CVD, or sputtering. At this time, since the metal mask 12b exists immediately above the undercut portion 11b of the groove pattern 11a, the material film 13 is not formed in the undercut portion 11b, and a void is formed.

  Note that the material film 13 may be formed in a vacuum atmosphere. Further, the sacrificial material 11 and the metal mask 12 b may be heated by the heater 14 when forming the material film 13.

  Next, as shown in FIG. 1E, the material film 13 is lifted off from the metal mask 12b by wet etching the metal mask 12b. More specifically, the metal mask 12b is etched away by the etching solution entering the gap from the gap between the material film 13 formed in the groove pattern 11a and the material film 13 formed on the metal mask 12b. . As a result, the material film 13 is lifted off and separated from the metal mask 12b. At this time, the sacrificial material 11 is preferably removed by etching at the same time, but if at least the metal mask 12b is removed by etching, the material film 13 can be a self-supporting film 13a. This film 13a becomes a medical instrument.

  According to this embodiment, since the material film 13 for medical instruments is formed on the metal mask 12b and the tubular film 13a is formed by lift-off, it is not necessary to etch the material film 13. Therefore, even a material that is difficult to be etched can be used as the material film 13, and various materials can be used.

  Examples of the material of the material film 13 include various metals (Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, lanthanoid, actinoid, Sc, Ti, V, Cr, Mn. , Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Al , Ga, In, Sn, Tl, Pb, Bi, B, Si, Ge, As, Sb, Te, Po), oxides and nitrides of the metals, alloys of the metals, stainless steel as biomaterials, CoCr Alloys, titanium alloys, bioelastic shape memory alloys having superelasticity, nylon, polypropylene, polydioxanone, polylactic acid, etc. can be used as the polymer material.

  Moreover, in this embodiment, the fall of the processing precision by heat | fever like the laser processing of a prior art can be suppressed.

In the present embodiment, Cu is used for the sacrificial material 11, but any material other than Cu may be used as long as the etching selectivity between the plating film 12 and the material film 13 can be obtained.
In the present embodiment, Ni is used for the plating film 12, but any material other than Ni may be used as long as the etching selectivity between the sacrificial material 11 and the material film 13 can be obtained.

  In this embodiment, the plated film 12 formed by the electrolytic plating method is used, but a film formed by a method other than the electrolytic plating method may be used. In the present embodiment, the metal mask 12b is used, but a mask using a material other than metal may be used.

[Second Embodiment]
2A to 2E are cross-sectional views illustrating a method for manufacturing a medical device according to one embodiment of the present invention. In the present embodiment, a stent will be described as an example of a medical device.

  First, as shown in FIG. 2A, a sacrificial tube 21 is prepared. The sacrificial tube 21 is made of Cu as in the first embodiment. The thickness of the sacrificial tube 21 is, for example, not less than 0.02 mm and not more than 0.5 mm.

  Next, a plating film (electroformed film) 22 is formed on the outer surface of the sacrificial tube 21 by electrolytic plating. That is, a plating film 22 is formed on the sacrificial tube 21 by flowing a plating solution (electroforming solution) through the sacrificial tube 21 and passing an electric current through the sacrificial tube 21. In FIG. 2, the plating film 22 is not formed on the inner surface of the sacrificial tube 21, but the plating film 22 may be formed on the outer surface and the inner surface of the sacrificial tube 21. The thickness of the plating film 22 is, for example, not less than 0.02 mm and not more than 0.5 mm. The plating film 12 is a Ni film, for example.

  Next, as shown in FIG. 2B, the plating film 22 is processed to form a metal mask (mask film) 22b having an opening pattern 22a on the outer surface of the sacrificial tube 21. More specifically, a photoresist film (not shown) is formed on the plating film 22, and the photoresist film is exposed and developed to form a resist pattern on the plating film 22. By etching the plating film 22 using this resist pattern as a mask, a metal mask 22b having an opening pattern 22a on the outer surface of the sacrificial tube 21 is formed. Next, the resist pattern is peeled off.

  Thereafter, as shown in FIG. 2C, the sacrificial tube 21 is half-etched using the metal mask 22b as a mask to form a groove pattern 21a to which the opening pattern 22a is transferred on the outer surface of the sacrificial tube 21. The groove pattern 21a has an undercut portion 21b, which is a portion where the sacrificial tube 21 located immediately below the metal mask 22b around the hole pattern 22a is etched. In order to form the undercut portion 21b, the above half etching is preferably isotropic etching, for example, wet etching or isotropic dry etching is preferably used.

  In the present embodiment, the outer surface of the sacrificial tube 21 is etched to about half the depth of the sacrificial tube 21 by half-etching. However, the present invention is not limited to this and does not penetrate the sacrificial tube 21. It is also possible to etch to various depths as long as they are etched.

  Thereafter, as shown in FIG. 2D, a material film 23 for a medical instrument is formed on the metal mask 22b and in the groove pattern 21a by vapor deposition, thermal spraying, CVD, or sputtering. At this time, since the metal mask 22b exists immediately above the undercut portion 21b of the groove pattern 21a, the material film 23 is not formed in the undercut portion 21b, and a void is formed. The film thickness of the material film 23 is, for example, not less than 0.02 mm and not more than 0.2 mm.

  Note that the sacrificial tube 21 may be rotated when the material film 23 is formed. Thereby, the material film 23 can be formed on the metal mask 22b with good uniformity. The material film 23 is preferably formed in a vacuum atmosphere. Further, the sacrificial tube 21 and the metal mask 22 b may be heated by the heater 24 when forming the material film 23.

  Next, as shown in FIG. 2E, the metal film 22b and the sacrificial tube 21 are wet-etched to separate the material film 23 from the metal mask 22b by lift-off. Specifically, the etching liquid enters the gap from the gap between the material film 23 formed in the groove pattern 21a and the material film 23 formed on the metal mask 22b, so that the metal mask 22b and the sacrificial tube 21 are formed. Etched away. As a result, the material film 23 is lifted off and separated from the metal mask 22b. As a result, it is possible to form a tubular film 23 a that is a self-supporting tubular object made of the material film 23. This tubular membrane 23a becomes a stent.

  Thereafter, surface treatment such as surface polishing or end surface R treatment of the stent may be performed as necessary, or the surface of the stent may be coated with a noble metal.

  According to this embodiment, since the material film 23 for medical instruments is formed on the metal mask 22b and the tubular film 23a is formed by lift-off, it is not necessary to etch the material film 23. Accordingly, even a material that is difficult to etch can be used as the material film 23, and various materials can be used. As the material of the material film 23, the same material as in the first embodiment can be used.

  In addition, when a stent is manufactured by using a material film 23 made of a biomedical shape memory alloy having superelasticity, it can also be applied to a stent used for a portion that can be bent by a joint. This will be described in detail below.

  In a stent that does not have superelastic characteristics, even when the shape of the stent is devised, bending followability and insertion characteristics are insufficient when inserted into a tortuous blood vessel together with a balloon catheter. In order to improve the bending followability, not a balloon expandable type but a self-expandable stent, that is, a stent having superelastic characteristics is suitable.

  By having superelastic characteristics, it becomes possible to use the stent not only at the bending followability at the time of insertion of the stent but also at a portion having a high bending deformability. Examples of superelastic materials include titanium alloys including nickel titanium, and specific superelastic materials include Ti-Ni, Ti-6Al-4V, Ti-Nb, Ti-Pd, and Ti-Zr-Nb. Binary, ternary or higher alloys containing titanium such as Ti-Mo-Sn, Ti-Mo-Ga, Ti-Ni-O and Ti-Ni-Al. Since titanium alloys are difficult to process, the prior art laser processing has low processability of titanium alloy stents. On the other hand, in this embodiment, even a material that is difficult to process, such as a titanium alloy, can be easily processed.

  In addition, when a stent is made of the material film 23 made of polylactic acid, polylactic acid is melted and absorbed in the body, so that the stent is not melted after the affected area is cured.

  Moreover, in this embodiment, the fall of the processing precision by heat | fever like the laser processing of a prior art can be suppressed. Accordingly, it is possible to manufacture a long stent having a longitudinal direction of 100 mm or more, which is difficult to manufacture by the conventional technique.

In the present embodiment, Cu is used for the sacrificial tube 21, but any material other than Cu may be used as long as the etching selectivity between the plating film 22 and the material film 23 can be obtained.
In the present embodiment, Ni is used for the plating film 22, but any material other than Ni may be used as long as the etching selectivity between the sacrificial tube 21 and the material film 23 can be obtained.
In this embodiment, the plating film 22 formed by the electrolytic plating method is used, but a film formed by a method other than the electrolytic plating method may be used. In the present embodiment, the metal mask 22b is used, but a mask using a material other than metal may be used.

  In the present embodiment, the same diameter sacrificial tube 21 having a constant outer diameter and inner diameter is used. For example, as shown in FIG. 3A, sacrificial tubes having different end diameters may be used. It is possible to use a sacrificial tube branched into branches as shown in FIG. Accordingly, it is possible to manufacture a tubular product that cannot be manufactured by the conventional technique.

  It is also possible to implement the first and second embodiments in combination with each other.

  Moreover, in 2nd Embodiment, although the example applied to the stent as a medical instrument is given, it is not limited to this, Various medical supplies which can be produced in 1st Embodiment or 2nd Embodiment One embodiment of the present invention can be applied to a device. For example, it can be applied to flow diverter, stent retriever system, cerebrovascular coil, guide wire, contrast marker, lower aortic filter, peripheral protection filter, medical clip, medical needle, metal or resin using springs, etc. is there.

11 Sacrificial material 11a Groove pattern 11b Undercut part 12 Plating film (electroformed film)
12a Hole pattern 12b Metal mask (mask film)
13 Material film for medical device 13a Self-supporting film 14 Heater 21 Sacrificial tube 21a Groove pattern 21b Undercut part 22 Plating film (electroformed film)
22a Open hole pattern 22b Metal mask (mask film)
23 Material membrane for medical instruments 23a Tubular membrane 24 Heater

Claims (9)

Forming a mask film on the sacrificial material;
Forming a photoresist film on the mask film, exposing the photoresist film, and developing to form a resist pattern on the mask film; and
Etching the mask film using the resist pattern as a mask to form a metal mask having an opening pattern on the sacrificial material;
Removing the resist pattern;
Forming a groove pattern in the sacrificial material by etching so as not to penetrate the sacrificial material using the metal mask as a mask;
Forming a film on the metal mask ;
Removing the film from the metal mask by etching the metal mask ;
A method for manufacturing a medical device, comprising: In claim 1,
  The etching in the step of forming the groove pattern is wet etching or isotropic dry etching,
  The groove pattern has an undercut portion that is a portion where the sacrificial material is etched immediately below the metal mask around the hole pattern,
  In the step of forming the film, the film is not formed in the undercut portion, and a void is formed. In claim 1 or 2,
  The method of manufacturing a medical device, wherein the step of forming a mask film on the sacrificial material is a step of forming a mask film made of a plating film on the sacrificial material by an electrolytic plating method. In any one of Claims 1 thru | or 3 ,
The sacrificial material is a sacrificial tube;
The step of forming the metal mask, a step of forming a metal mask having an opening pattern on the outer surface of the front Symbol sacrificial tube,
The step of separating the film is a step of forming a tubular article made of the film by separating the film from the metal mask . In claim 4 ,
The method of forming a film is a process of forming a film on the metal mask while rotating the sacrificial tube. In claim 4 or 5 ,
The method of manufacturing a medical device, wherein the sacrificial tube has a branched tube shape or a tube shape having different end diameters. In any one of Claims 1 thru | or 6 ,
The method of manufacturing a medical device is characterized in that the step of forming the film is a step of forming a film on the metal mask while heating the sacrificial material. In any one of Claims 1 thru | or 7 ,
The process for forming the film is a process for forming a film on the metal mask by vapor deposition, thermal spraying, CVD, or sputtering. In any one of Claims 1 thru | or 8 ,
The membrane is a membrane made of one material selected from the group of stainless steel, CoCr alloy, titanium alloy, superelastic biometric shape memory alloy, nylon, polypropylene, polydioxanone, and polylactic acid. A method of manufacturing a medical device.

Images