WO2008041692A1

WO2008041692A1 - Laser working apparatus, laser working method, and stained glass manufacturing method

Info

Publication number: WO2008041692A1
Application number: PCT/JP2007/069248
Authority: WO
Inventors: Tadashi Okuno; Hiroshi Tsugita; Akira Watanabe; Tetsumi Sumiyoshi
Original assignee: Photo-Physics Laboratory Inc.; Cyber Laser Inc.
Priority date: 2006-10-02
Filing date: 2007-10-02
Publication date: 2008-04-10
Also published as: JP2009297719A; TW200827082A

Abstract

Provided are a capillary working apparatus and a working method using a femto-second laser. The working method comprises splitting one laser beam of a femto-second into a plurality of beams by beam splitting means, changing the directions of the split individual laser beams by beam deflecting means, irradiating a tubular workpiece in different directions with the laser beams, and rotating and moving the workpiece in the direction of the rotating axis thereby to perform the laser working operation. A number of openings can be formed into a mesh shape in the workpiece by the working operation so that the working method is suited for making stained glass. The working apparatus can be constituted to include a femto-second laser device, a chuck for clamping the workpiece, a beam splitter and a reflecting mirror.

Description

Specification

Laser processing apparatus and processing method for small diameter tube

Technical field

[0001] The present invention relates to a laser processing apparatus and method using a femtosecond laser, and more particularly to an apparatus and method for processing a small-diameter tube represented by a stent.

Background art

[0002] Currently, medical devices called stents are used for treatment, and stainless steel or the like is used as a material. A stent is formed by irradiating a thin tube with an outer diameter of several millimeters or less (for example, 1 mm or less) with a laser beam to form a mesh. Such stents have increased flexibility to reach destinations, reduce the diameter of the material tube to accommodate smaller blood vessels and avoid post-processing shrinkage, In order to keep it in place, it is necessary to reduce living body rejection.

[0003] Conventionally, such problems have been dealt with by improving the flexibility by configuring a tube having a mesh structure, using a thinner tube as the processing raw material, or using a material with high biocompatibility. It has been carried out by coating the tube surface or providing a drug delivery system (DDS) property to release the immunosuppressive agent slowly.

Patent Document 1: Japanese Patent Laid-Open No. 5-309489

Patent Document 2: Japanese Patent Laid-Open No. 7-276071

Patent Document 3: Japanese Patent Publication No. 11 5186

Patent Document 4: Japanese Patent Publication No. 2003 334677

Patent Document 5: Japanese Unexamined Patent Publication No. 2005-109323

Patent Document 6: Japanese Unexamined Patent Publication No. 2005-109322

Patent Document 7: Japanese Unexamined Patent Publication No. 2006-68762

Disclosure of the invention

Problems to be solved by the invention

[0004] When manufacturing a stent by processing a thin tube as described above, a YAG laser has been generally used. In the case of a thin tube with a diameter of lmm or less as described above, the YAG Processing by The One has reached the limit of miniaturization. Furthermore, when forming a stent using this technology, the force that compresses the outer circumferential force after processing a tube with a large diameter and then reduces the diameter. In this case, the stent undergoes deformation in both the compression and expansion directions. The risk of breakage increases and the risk during use increases.

[0005] Further, regarding the use of a material having high biocompatibility, for example, there is a cobalt chromium force S, which has high heat resistance, so that heat processing using a conventional YAG laser is difficult. Also, a force S that can use a shape memory alloy such as nickel titanium as the material of the stent S, which cannot be heat processed.

As described above, it is extremely difficult to produce a stent having a small diameter by the conventional technique.

Means for solving the problem

[0006] In order to solve the problem, the present invention provides the following means.

(1) A laser processing device for processing a tubular workpiece, a laser device for outputting femtosecond laser light, a chuck for holding the workpiece, and a plurality of the femtosecond laser beams. Dividing means for dividing, a plurality of divided laser beams in different direction forces, a deflecting means for changing the direction of the workpiece, and a rotation for moving the chuck in the axial direction of rotation while rotating the chuck. And a moving mechanism.

Furthermore, it is possible to have at least one of the following features (2) to (4).

(2) The splitting unit includes a beam splitter that splits the femtosecond laser light into 1: 1.

(3) The chuck is configured to hang and hold the workpiece from above.

(4) Further, it has a container having a transmission part that transmits the plurality of divided laser beams, and the chuck can hold the object to be processed at least partially inside the container, A plurality of divided laser beams are irradiated from the outside of the container to the object to be processed through the transmission part. By processing in liquid, so-called nanoparticles generated in microfabrication using femtosecond laser can be removed, and adverse health effects can be avoided.

(5) A laser processing method for processing a tubular workpiece, which includes femtosecond laser light A step of dividing the femtosecond laser light into a plurality of steps, a step of deflecting the plurality of divided laser lights from the different directions toward the tubular workpiece, and the tubular step And moving the workpiece in the direction of the central axis while rotating the workpiece about the central axis, and irradiating the tubular workpiece with the plurality of laser beams whose directions are changed. Furthermore, it is possible to have at least one of the following features (1) to (9).

(6) In the dividing step, the step of dividing the femto laser beam into 1: 1 is performed once or a plurality of times.

(7) The tubular workpiece is held in the upper part and suspended.

(8) In the irradiation and processing step, sequential irradiation processing is performed from the bottom to the top of the tubular workpiece.

(9) Further, the portion of the tubular workpiece to be irradiated and processed exists in the liquid. By processing in liquid, so-called nanoparticles generated in microfabrication using a femtosecond laser can be removed, and adverse health effects can be avoided.

(10) A method for manufacturing a stent, which is produced by forming a large number of openings in a tubular work piece that is a metal by the method described in (5) above. Furthermore, the above ½) to (9) and the following

It is possible to have at least one feature of (11).

(11) The outer diameter of the tubular workpiece is lmm or less.

The invention's effect

[0007] By using a femtosecond laser, a small tube having a diameter of 1 mm or less can be processed, and in particular, a stent can be manufactured. Further, by dividing the laser beam into a plurality of parts, many processes can be performed at a time, and the processing speed can be increased.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a diagram schematically showing a processing apparatus of the present invention. As shown in the figure, a femtosecond laser beam 11 is output from the femtosecond laser apparatus 10. Here, “femtosecond laser light” means a pulse laser having a pulse width of 1000 femtoseconds or less. The outputted laser beam 11 is divided into four divided beams 14 by a beam dividing means 21. The beam splitting means 21 is, for example, 1 splitter. Each of the divided beams enters the beam deflecting means 22. The direction of each beam is changed by the beam deflecting means 22 and irradiated on the workpiece 32 held by the chuck 31. The beam deflecting means 22 can be reflecting mirrors 22a to 22d that change the direction of each beam in a desired direction.

[0009] The beam splitting means 21 can also have a so-called beam shaper that matches the beam splitter so as to perform waveform shaping so that the noise does not spread due to group velocity dispersion. In addition, when sub-micron order processing is performed with a femtosecond laser, it is difficult to stably irradiate the workpiece 32 with the laser beam 11 because the optical axis of the laser beam 11 is fluctuating. It is effective to use an automatic optical axis adjustment system, la, and so-called auto-aligner so that the workpiece 32 can always be irradiated with the laser beam 11 accurately.

In FIG. 1, the beam is split into four split laser beams 14 by the beam splitting means 21, but it is not limited to this, and it may be split into a larger number, or 2 or 3 You may divide into. It is preferably divided into a maximum of 8. On the other hand, a configuration without the beam splitting means 21 is also possible. In this case, one laser beam is incident on the deflecting means 22.

When the laser beam 11 is divided into a plurality of pieces, it is usually divided so that the intensities are equal. At this time, it can be conveniently constructed by using a beam splitter that splits 1: 1. 1: 1 splitting can be repeated twice to make 4 splits. Fig. 2 shows the means for creating a laser beam 14 divided into four parts with a 1: 1 beam splitter doubled. In addition to 2 divisions and 4 divisions, 8 divisions, 16 divisions, etc. can be easily divided into powers of 2. However, as described above, a maximum of 8 is preferable.

Further, it is necessary to accurately adjust the optical axis of the divided laser beam during processing. When all the optical axes of the divided laser beams 14 are applied to the workpiece, the straight line extending the optical axes is preferably a single point on the central axis 13 of the workpiece 32 that is tubular. Intersect. Ideally, it intersects the central axis 13 perpendicularly.

The workpiece 32 is held on the chuck 31. As shown in FIG. 1, the chuck 31 preferably holds the workpiece 32 so as to hang from above. A collet chuck is an example of such a chuck that can be held. The collet chuck has a hole diameter of 10 mm. Prepare multiple items that have been changed in increments of cron, select a chuck that matches the diameter of the workpiece 32, and press the force S.

The chuck 31 is attached to a rotation and movement mechanism 39. For this reason, the chuck 31 can move in the axial direction of the rotation while rotating. Therefore, the tubular workpiece 32 moves in the direction of the central axis 13 while rotating around the central axis 13. It is possible. The rotation and movement mechanism 39 can be realized by using a combination of an existing rotation mechanism and a movement mechanism. By connecting the rotating mechanism to the chuck 31 and mounting the rotating mechanism on a table attached to the moving mechanism, the chuck 31 can be moved while rotating with the force S.

[0013] For example, when manufacturing a stent, the workpiece 32 can be a metal thin tube having an outer diameter of 0.1 mm, an inner diameter of 0.05 mm, and a wall thickness of 0.025 mm. If the outer force is less than or equal to Slm, the stent can be used as a stent. It can also be processed with an outer diameter of S lmm or more.

According to the present invention, it is possible to satisfactorily produce a stent having an outer diameter of 1 mm or less.

[0014] Next, a method of manufacturing a stent using such an apparatus will be described. Since the stent is formed in a mesh shape, the mesh is formed by irradiating the femtosecond laser 11 to form an opening on the side surface of the thin tube 33 that is the workpiece 32. Needless to say, the following method can be applied to a general laser processing method in addition to the case of manufacturing a stent.

FIG. 3 is a side view showing such a mesh, and an opening 34 is formed in the thin tube 33. Figure 4 shows the operation of the device. Since the narrow tube 33 is held suspended from above, its central axis is in the vertical direction. This opening 34 is formed in the circumferential direction of the narrow tube 33. For example, in the apparatus shown in FIGS. 1 and 4, the laser beam 11 is divided into four parts. Four openings 34 are formed on the side. The laser beam 11 is irradiated for the first time, and then the second irradiation is performed by rotating the chuck 31 without changing the height. The number of openings 34 that can be formed at one time is determined by the number of laser beams 11 divided by the beam splitter 21. For example, when the laser beam 11 is divided into four, the same height of the side surface of the capillary 33 is obtained by two irradiations. 8 openings can be formed.

[0016] Next, the chuck 31 is moved up and down to open at a different height on the side surface of the thin tube 33. Form part 34. At this time, it is preferable to form the opening 34 from the lower part of the thin tube, that is, while lowering the chuck 31. Although it can be formed from the upper part of the thin tube 33, the portion processed into a mesh shape is weak in strength and may break during processing.

If the rotation and movement are performed simultaneously, the height formed by the opening 34 can be changed by the first irradiation and the second irradiation, so that a spiral pattern as shown in FIG. 5 can be formed. it can.

FIG. 6 shows a state of processing on the surface of the thin tube 3. Split laser light beam 14

(Only one is described here) is irradiated so that the condensing position is formed on the surface of the narrow tube, and the narrow tube is scanned in a circle of the opening 34. Since the laser beam 14 is a pulse, it is irradiated so that the laser beam spot appropriately overlaps the surface of the thin tube. By processing along the irradiation trajectory, a circular opening is formed on the surface of the thin tube. Here, the reason for scanning the narrow tube 33 connected by the laser beam 14 is that the laser beam is more stable when it is fixed.

[0018] When the opening 34 is processed, the speed at which the laser beam 14 divided on the surface of the thin tube is scanned in a circle is preferably a linear velocity of 0.1 mm / second or less on the surface of the thin tube 33. The linear velocity also depends on the beam diameter of the laser beam 11. When the beam diameter is small, the diameter of the opening 34 becomes small, and the processing line width becomes small. Therefore, fine processing is possible, but the processing speed is reduced. Conversely, if the beam diameter is increased to increase the processing line width, the processing speed increases. Therefore, the optimum beam diameter depending on the processing line width can be obtained.

The pulse frequency of the femtosecond laser output from the sales femtosecond laser is as small as about 1000 / second. When the scanning linear velocity is 0.1 mm / sec, the distance between the laser spot centers is 0.1 l〃m. Therefore, when the laser beam spot size is l〃m, 90% overlap of laser spots can be obtained.

[0019] The number of openings 34 per side of the thin tube is the product of the number of divided laser beams (4 in the above case) and the number of irradiations per rotation (2 in the above). The stent pattern is a repetitive design of the same shape, and is repeated so that the side of the pipe is neatly filled with, for example, 12, 20, and 25 per rotation of the capillary side. For example, the opening 34 is once on the side of the narrow tube 33. If there are 12 per roll, divide the laser beam 11 into 6 and process the first stage with 2 irradiations. When 20 pieces are lined up, the laser beam 11 is irradiated 4 times and processed in one step.

[0020] In the present invention, a stent can be manufactured using a thin tube. This can be realized by using a femtosecond laser. When the opening 34 is formed by the force laser beam 11, fine debris is generated. This debris becomes nanometer order particles. That is, the nanoparticles are scattered around as debris. Nanoparticles can be taken into the human body by, for example, suction, which can adversely affect health. Therefore, the laser processing apparatus and processing method for preventing adverse effects on the human body will be described next.

FIG. 7 is a view schematically showing the periphery of the chuck 31. As shown in the figure, a container 35 such as a water tank filled with a liquid 36 such as water is provided, and the chuck 31 places the thin tube 33 in the container 35 so that the laser irradiation portion of the work piece such as the thin tube 33 is immersed in the liquid. Hold on. Although not shown in the figure, the rotation and movement mechanism 39 is assumed to be installed in the same manner as in FIGS. The container 35 is formed of a transparent material such as glass so that the laser beam 11 can be transmitted, or has a structure in which a window portion made of a material that can transmit the laser beam 11 is provided and the laser beam 11 is introduced therefrom. Here, the term “transparent” does not necessarily mean that 100% light is transmitted, and includes a case where laser light can be transmitted to some extent. Processing is the same as above. In addition, when the power when reaching the object to be processed decreases due to absorption or reflection of laser light by water, the wall of the container, etc., the amount of decrease can be increased for irradiation.

In this embodiment, since the thin tube 33 as the workpiece is located in the water, the nanoparticles are not scattered in the air. Therefore, it can process very safely. Further, the liquid into which the workpiece 32 is immersed is not limited to water, but can be processed by the laser beam 11 and may be any liquid that does not adversely affect the workpiece 32. The container 35 may be provided with an inlet and an outlet for fluid to flow.

[0023] The several embodiments of the present invention have been described above. Obviously, modifications may be made without departing from the technical spirit of the claimed invention. Industrial applicability

[0024] According to the present invention, tubules of lmm or less can be processed into stents, and nanoparticles, etc. It is possible to provide laser processing equipment and processing methods that can prevent adverse effects on the human body caused by

Brief Description of Drawings

FIG. 1 is a diagram schematically showing a processing apparatus of the present invention.

FIG. 2 is a configuration diagram of a 4-split beam splitter.

FIG. 3 is an enlarged view of a stent.

FIG. 4 is a view showing a method for manufacturing a stent according to the present invention.

FIG. 5 is an enlarged view of a stent according to another embodiment.

FIG. 6 is a view showing a stent processing method according to the present invention.

FIG. 7 is a diagram schematically showing a processing apparatus for preventing debris from scattering.

Explanation of symbols

[0026] 10 femtosecond laser device

11 Laser light

13 Center axis of tubular workpiece

14 Split laser light

21 Beam splitter

22 Beam deflection means

22a-22d reflector

23 1: 1 split beam splitter

31 Chuck

32 Workpiece

33 tubules

34 opening

39 Rotating and moving mechanism

Claims

The scope of the claims

[1] A laser processing apparatus for processing a tubular workpiece,

A laser device that outputs a femtosecond laser beam; a chuck that holds the workpiece; a dividing unit that divides the femtosecond laser beam into a plurality of pieces; and a plurality of divided laser beams from the different directions. A laser processing apparatus comprising: a deflecting unit that changes the direction of the workpiece, and a rotation and movement mechanism that moves the chuck in the axial direction of rotation while rotating the chuck.

[2] The laser processing apparatus according to [1], wherein the splitting unit includes a beam splitter that splits the femtosecond laser light into 1: 1.

[3] The apparatus according to claim 1, wherein the chuck is configured to hang and hold the workpiece from above.

[4] Furthermore, it has a container having a transmission part that transmits the plurality of divided laser beams, the chuck can hold the object to be processed at least partially inside the container, 2. The apparatus according to claim 1, wherein the plurality of divided laser beams are irradiated from the outside of the container to the object to be processed through the transmission unit.

[5] A laser processing method for processing a tubular workpiece,

Outputting femtosecond laser light;

Dividing the femtosecond laser light into a plurality of parts,

A step of deflecting a plurality of divided laser beams from different directions toward the tubular workpiece,

The tubular workpiece is moved in the direction of the central axis while rotating around the central axis, and the tubular workpiece is irradiated with a plurality of laser beams whose directions are changed. .

6. The laser processing method according to claim 5, wherein the dividing step includes performing the step of dividing the femto laser beam into 1: 1 one or more times.

7. The laser processing method according to claim 5, wherein the tubular workpiece is held in an upper part and is suspended.

8. The laser processing method according to claim 5, wherein in the irradiation and processing step, the irradiation processing is sequentially performed from the bottom to the top of the tubular workpiece.

[9] The processing method according to claim 5, wherein the portion to be irradiated and processed of the tubular workpiece exists in the liquid.

[10] A stent manufacturing method, wherein the tubular workpiece is a metal, and is produced by forming a large number of openings in the workpiece by the method according to any one of claims 5 to 9.

11. The stent manufacturing method according to claim 10, wherein the outer diameter force of the tubular workpiece is not more than mm.