JPH05305472A - Laser beam machine - Google Patents

Abstract

PURPOSE:To carry out accurate machining of a specific shape on a work piece by converging a laser beam with a lens having a specific shape. CONSTITUTION:When a silicon nitride sintered ceramic plate 2 is irradiated with a KrF excimer laser beam (248nm wave length, 30nsec pulse width) through a conical lens 1a made of a molten quartz, a ring with an inner diameter of 50mum and a width of 200mum is drawn. By a 500 pulse irradiation with an energy of 4J/cm<2>, a groove with a depth of 45mum is formed. By this method, a laser abrasion is activated only in a ring shaped area, and an annular grooving can be performed without moving a sample 2. The annular diameter is adjusted by varying a distance between the lens 1a and the sample 2, and the annular width is adjusted by varying the apex angle alpha or the refractive index of the conical lens 1a. In addition, if the shape of the lens is made cylindrical, a linear spot is obtained; and if a triangular prism, a parallel spot is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus used when performing non-contact fine processing of a substance by laser light.

[0002]

2. Description of the Related Art In recent years, a welding / cutting technique utilizing a carbon dioxide laser, an Nd: YAG laser, or the like has been widely used. The use of laser light has an advantage that it has a small energy effect on a workpiece due to its high energy density and that it can perform highly accurate machining without contact. Recently, the application of lasers to non-contact microfabrication and surface modification has been promoted, and in particular, research and development on laser ablation using excimer laser light having a wavelength in the ultraviolet region has become active. ..

Laser ablation constitutes a substance by irradiating the substance with laser light (for example, excimer laser light having a shorter wavelength and higher energy per photon than a carbon dioxide gas laser or Nd: YAG laser). Breaking the bonds between atoms or molecules by light energy,
It is a method of evaporating. This enables fine processing in a non-contact state. It is also possible to partially induce a chemical reaction by light energy or change the crystal structure to change the properties in the vicinity of the surface (surface modification).

Conventionally, as a method of laser ablation, as shown in FIG. 10, a method of focusing excimer laser light on a sample surface by a spherical lens has been used. According to this method, the laser beam can be processed into a circular spot for laser processing, but the spot is not limited to a circular shape and has a desired shape (for example, a donut shape or a linear shape).
In order to perform fine processing or surface modification, it is necessary to move the sample while maintaining the spot.

For this reason, it is necessary to move the sample with high accuracy, and if the accuracy is lowered even a little, the sample cannot be processed into a desired shape, and the reforming position is displaced.

[0006]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to solve the above-mentioned technical problems and to solve a specific shape.
It is an object of the present invention to provide a laser processing apparatus capable of performing laser processing accurately with a simple structure and quickly.

[0007]

[Means and Actions for Solving the Problems]

(1) A laser processing apparatus according to claim 1 for achieving the above object, comprises a laser light source and a lens for condensing a laser beam on a substance, and the lens forms a ring-shaped processing region. It is a conical lens that can be used. According to the above configuration, the ring-shaped region can be easily processed without moving the sample. (2) Further, the laser processing apparatus according to claim 2 for achieving the above object uses a cylindrical lens capable of forming a linear processing region.

According to this, it is possible to easily process the linear region without moving the sample. (3) The laser processing apparatus according to claim 3 uses a triangular prism-shaped lens capable of forming one or a plurality of linear processing regions. According to this, it is possible to easily process a wide linear region without moving the sample. (4) The laser processing device according to claim 4 is the laser processing device according to claim 2 or 3.
In the laser processing apparatus described above, a plurality of the lenses are arranged in parallel on one transparent plate.

According to this, a plurality of parallel linear regions can be processed at a time without moving the sample. (5) The laser processing device according to claim 5 is the laser processing device according to claim 2 or 3.
In the laser processing apparatus described above, a plurality of the lenses are arranged on one transparent plate and intersect each other at a predetermined angle.

According to this, a plurality of intersecting linear regions can be processed at one time without moving the sample.

[0011]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 is a specific example of the present invention and shows a method of forming a ring-shaped region 3a on the surface of a sample 2 by condensing laser light such as an excimer laser by a conical lens 1a.

For example, KrF excimer laser light (wavelength 24
8 nm, pulse width 30 nsec) is irradiated on the silicon nitride (Si ₃ N ₄ ) sintered ceramics plate 2 through the fused silica conical lens 1a, the inner diameter is 50 μm, and the width is 200 μm.
A μm ring can be obtained. Irradiating 500 pulses with an energy of 4 J / cm ² can form a groove having a depth of 45 μm.

According to this method, laser ablation occurs only in the ring-shaped region and the annular groove can be processed, so that fine processing and surface modification can be performed without moving the sample 2. The diameter of the ring can be adjusted by changing the distance between the lens 1a and the sample 2.

Further, the width of the annular portion can be adjusted by changing the term angle α or the refractive index of the conical lens 1a. FIG. 2 shows another embodiment of the present invention, in which laser light is linearly condensed on the sample 2 by the cylindrical lens 1b. Therefore, it is possible to cause laser ablation in the linear region 3b.

FIG. 3 shows an example in which a lens 1c having a triangular prism surface is used. In this case, by adjusting the distance between the sample 2 and the lens 1c, it is possible to irradiate the sample 2 with one laser beam or two parallel linear spots 3c. In addition, as shown in FIG. 4, by arranging a plurality of cylindrical lenses 1d in parallel on the transparent substrate 1, it is possible to cause laser ablation simultaneously in a plurality of on-line regions of the sample 2 (see FIG. 5). Therefore, it is possible to form striped patterns at precise intervals.

Further, as shown in FIG. 6, by using two cylindrical lenses 1e intersecting each other at an arbitrary angle θ (illustrated at right angles in the figure), laser ablation can be caused in two linear regions. Yes (see Figure 7).
Further, as shown in FIG. 8, by using a lens in which two triangular prism surfaces 1f are orthogonal to each other, laser ablation can be caused in a cross-shaped region (see FIG. 9).

Although the present invention has been described based on the embodiments, the present invention is not limited to the above embodiments. For example, as a laser, not only an excimer laser having an emission wavelength in the ultraviolet region but also a carbon dioxide gas laser, Nd:
YAG laser, argon laser, He-Cd laser, N
The 2nd harmonic, the 3rd harmonic, etc. of a d: YAG laser can be used.

Other various changes can be made without changing the gist of the present invention.

[0019]

As described above, according to the laser processing apparatus of the first aspect, the ring-shaped region can be easily processed without moving the sample, which causes a problem of movement accuracy. Can be processed into an accurate ring shape without
According to the laser processing apparatus of the second aspect, since the linear region can be easily processed without moving the sample, accurate processing can be performed without causing a problem of movement accuracy.

According to the laser processing apparatus of the third aspect,
A wide linear region can be easily processed without moving the sample. Further, by adjusting the position of the lens, it is possible to adjust the distance between the lines or to make the lines one. According to the laser processing apparatus of the fourth aspect, since a plurality of parallel linear regions can be processed at a time without moving the sample, accurate stripes can be formed.

According to the laser processing apparatus of the fifth aspect,
Since it is possible to process a plurality of intersecting linear regions at once without moving the sample, it is possible to form a plurality of sets of stripes having different angles.

[Brief description of drawings]

FIG. 1 is a view showing a state in which a conical lens collects laser light to form a ring-shaped spot on a sample surface.

FIG. 2 is a diagram showing a state in which laser light is linearly condensed on a sample by a cylindrical lens to form a linear region.

FIG. 3 is a diagram showing a state where one laser beam or two parallel linear spots are formed by using a lens having a triangular prism surface and adjusting the distance between the sample and the lens.

FIG. 4 is a diagram showing a state in which a plurality of line-up regions are simultaneously formed by arranging a plurality of cylindrical lenses in parallel.

FIG. 5 is a plan view showing a plurality of on-line regions formed by the method of FIG.

FIG. 6 is a diagram showing a state where two intersecting linear regions are simultaneously formed by using two cylindrical lenses that intersect each other at an arbitrary angle θ.

7 is a plan view showing two on-line regions produced by the method of FIG.

FIG. 8 is a diagram showing a state in which a grid-shaped region is simultaneously formed by using a lens in which two triangular prism surfaces are orthogonal to each other.

9 is a plan view showing a cross-shaped linear region formed by the method of FIG.

FIG. 10 is a diagram showing a conventional method in which laser light is focused on a sample surface by a spherical lens and processed while moving the sample.

[Explanation of symbols]

 1a to 1f lens 2 sample 3a to 3c spot

Claims (5)

[Claims] 1. A laser light source used for a laser ablation method in which a bond between atoms or molecules constituting a substance is broken and evaporated by irradiation with a laser beam, and a laser light source and a lens for condensing the laser beam on the substance are provided. The laser processing apparatus, wherein the lens is a conical lens capable of forming a ring-shaped processing area. 2. A laser ablation method, which is used in a laser ablation method in which a bond between atoms or molecules constituting a substance is broken and evaporated by irradiation with a laser beam, and includes a laser light source and a lens for condensing the laser beam on the substance. The laser processing apparatus, wherein the lens is a cylindrical lens capable of forming a linear processing region. 3. A laser ablation method, which is used for laser ablation method in which bonds between atoms or molecules constituting a substance are broken and evaporated by irradiation with laser light, and includes a laser light source and a lens for focusing the laser light on the substance. The laser processing device, wherein the lens is a triangular prism-shaped lens capable of forming one or a plurality of linear processing regions. 4. The laser processing apparatus according to claim 2, wherein a plurality of the lenses are arranged parallel to each other on one transparent plate. 5. The laser processing apparatus according to claim 2, wherein a plurality of the lenses are arranged on one transparent plate and intersect each other at a predetermined angle.