JP2014184483A - Laser apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser apparatus that is improved in accuracy for processing a brittle material to enhance productivity.SOLUTION: The laser apparatus includes: a laser oscillator for emitting a laser beam; a reflecting mirror for reflecting the laser beam; a spindle rotatable about one rotation axis; and a condensing lens for condensing the laser beam reflected by the reflecting mirror at a condensing part, where a reflecting surface of the reflecting mirror and the rotation axis are fixed so as to define an angle other than 90 degree between them. In the laser apparatus, rotating the spindle about the rotation axis can rotate the reflecting mirror about the rotation axis thereby rotating the condensing part.

Description

  The present invention relates to a laser apparatus whose main purpose is to process a workpiece made of a brittle material.

Currently, processing of brittle materials represented by glass is performed, but brittle materials are easily broken, and the material is easily broken during processing by force generated during processing represented by cutting resistance. Currently, methods of reducing the cutting force by reducing the amount of processing and processing using a laser capable of non-contact processing are performed.

JP-A-8-192286 The mechanism as shown in Patent Document 1 is used to facilitate processing by spirally rotating the laser beam. However, when processing a brittle material, there is a problem that processing time is required. Many.

Currently, brittle materials represented by glass are being processed. However, brittle materials are easily broken, and there is a problem that cracks are generated from the processing points to portions other than the processing portions during processing, and the target processing shape cannot be realized. The force that generates a crack mainly includes an external force applied to the workpiece and an internal stress of the workpiece.

As a representative example of the external force applied to the workpiece, cutting resistance by a grindstone processing method can be given. In order to reduce the cutting resistance, there is a method of reducing the processing amount, but there is a problem that the processing time increases and the processing cost increases.

A processing method using a laser that generates almost no external force applied to the workpiece is also being carried out. Laser processing is a method of increasing the energy density by condensing light energy on a small area with a condensing lens and processing with high energy. This method has an advantage that it can be processed in a non-contact manner with respect to the workpiece and does not generate cutting resistance as compared with grinding wheel processing.

  As shown in FIG. 1, a typical laser device makes laser light 102 emitted from a laser oscillator 101 enter a condensing lens 103, and light enters a condensing portion (not shown) including a focal point 104 of the condensing lens. It is common to use an optical system that collects light. An example in which the workpiece 105 is grooved by laser from the point m to the point n using the system shown in FIG. 2 using the laser apparatus shown in FIG. 1 will be described. The system shown in FIG. 2 includes a laser oscillator 101, a condenser lens 103, and a workpiece moving stage (not shown).

  First, the workpiece 105 is fixed to a workpiece moving stage (not shown). Next, the workpiece moving stage (not shown) is moved to a position where the laser beam is incident on the point m of the workpiece 105. Next, at the same time as the laser beam 102 is emitted from the laser oscillator 101, a workpiece moving stage (not shown) is linearly moved at a predetermined speed to a position where the laser beam is incident on the n point of the workpiece 105, thereby performing laser processing. I do. When laser processing is performed up to n points, the laser oscillator 101 stops the output of the laser beam 102.

  FIG. 3 is a diagram showing a state in which the groove processing by the laser beam 102 has progressed to the point n. FIG. 4 shows a cross-sectional view of the processed portion 106 laser-processed from the m point to the n point. The shape of the bottom surface 107 of the processed portion 106 shown in FIG. 4 is related to the size of the light collecting portion, and generally has a shape with a small area of the bottom surface 107. When a force is applied to the workpiece 105, the force concentrates on the bottom surface 107 of the processing portion 106 having a small area, and if the magnitude of the force exceeds a certain level, the bottom surface 107 may crack. Becomes larger. FIG. 5 shows an image in which a crack 108 is generated in the workpiece 105 during laser processing. In particular, when a material having a large internal stress is processed, a part of the material is removed by laser processing, the balance of internal stress is lost, and a force is generated on the bottom surface 107 of the processed portion 106. The possibility of breaking will increase.

A typical configuration of the laser apparatus according to the present invention includes a laser oscillator that emits laser light, a reflection mirror that reflects the laser light, a spindle that can rotate around a single rotation center axis, and a laser that is reflected by the reflection mirror. A laser device comprising a condensing lens for condensing light on a condensing portion, wherein an angle formed by a reflection surface of the reflection mirror and the rotation center axis is fixed at an angle other than 90 degrees Device.
Further, in the laser device, the condensing part is rotated by rotating the spindle about the rotation center axis and rotating the reflection mirror about the rotation center axis.

According to the present invention, the processing speed of a brittle material can be increased, and productivity can be improved.

It is a figure which shows typical laser processing. It is a figure which shows the example which carries out the groove process of the to-be-processed object by laser processing. It is a figure which shows the state which groove processing by the laser beam advanced. It is sectional drawing of the process part laser-processed. It is a figure which shows the image which the crack generate | occur | produced in the to-be-processed object during laser processing. It is a figure which shows the comparative example with this invention. It is a figure which shows Example 1 of this invention. It is a figure which shows Example 2 of this invention. It is a figure which shows the locus | trajectory of the center point of the condensing part of the workpiece surface. It is a figure which shows the external appearance of the workpiece after a laser processing. It is a figure which shows the cross section of the process part of the workpiece shown in FIG.

  First, a comparative example with the present invention is shown in FIG.

  As shown in FIG. 6, the laser beam 102 emitted from the laser oscillator 101 is incident on the reflecting surface (D) of the reflecting mirror 201 and reflected. The laser beam 201 reflected by the reflection mirror 201 enters the condenser lens 103 and is condensed on the focal plane (E). The reflection mirror 201 is fixed to the spindle 202, and the reflection mirror 201 can also rotate about the rotation center axis (b-b ') when the spindle 202 rotates about the rotation center axis (b-b'). The spindle 202 and the reflection mirror 201 are fixed so that the angle formed by the rotation center axis (b-b ') of the spindle 202 and the reflection surface (D) of the reflection mirror 201 is α degrees. In the case of the comparative example, α is 90 degrees.

Further, the angle θ formed by the center axis (aa ′) of the laser beam 201 emitted from the laser oscillator 101 and the rotation center axis (bb ′) of the spindle 202 is set to 45 degrees. . The laser beam 102 reflected by the reflection mirror 201 enters the condenser lens 103 and is condensed on the focal plane (E).

  In the laser apparatus shown in FIG. 6, when the spindle 202 is rotated around the rotation center axis (bb ′), the reflection surface (D) of the reflection mirror 201 fixed to the spindle 202 is also rotated at the rotation center axis (bb ′). Rotate with. However, even if the reflecting surface (D) is rotated, since the α is 90 degrees, the incident angle and the reflecting angle of the laser beam 102 incident and reflected on the reflecting surface (D) do not change. Therefore, the position of the condensing part s0 condensed by the condensing lens 103 does not change.

  The position of the condensing portion s0 is determined by the value of θ, and when θ is 45 degrees, the condensing portion s0 is located between the optical axis of the condensing lens 103 and the condensing surface (E) as shown in FIG. When the angle θ is an angle other than 45 degrees, the position of the condensing portion s0 is a portion other than the intersection of the optical axis of the condensing lens 103 and the condensing surface (E).

  Examples of the present invention are shown below. However, it goes without saying that the claimed contents of the present application are not limited to this embodiment.

  FIG. 7 shows a first laser device 1000 of the present invention. A first embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 7, the laser beam 102 emitted from the laser oscillator 101 is incident on the reflection surface (D) of the reflection mirror 201 and reflected.

  The laser beam 102 reflected by the reflection mirror 201 enters the condenser lens 103 and is condensed on the focal plane (E). The reflection mirror 103 is fixed to the spindle 202, and when the spindle 202 rotates about the rotation center axis (b-b '), the reflection mirror 201 can also rotate about the rotation center axis (b-b').

The spindle 202 and the reflection mirror 201 are fixed so that the angle formed by the rotation center axis (b-b ') of the spindle 202 and the reflection surface (D) of the reflection mirror 201 is α degrees. In the present invention, α is an angle other than 90 degrees. In order to clearly show that α is an angle other than 90 °, α = 90 + ε may be indicated. However, ε in the present invention takes a value other than zero.

Furthermore, the center axis (aa ′) of the laser beam 102 emitted from the laser oscillator 101 is arranged so as to coincide with the intersection of the rotation center axis (bb ′) of the spindle 202 and the reflecting surface (D). Has been. Further, the angle θ formed by the center axis (aa ′) of the laser beam 201 emitted from the laser oscillator 101 and the rotation center axis (bb ′) of the spindle 202 is set to 45 degrees. .

  The laser beam 102 reflected by the reflection mirror 201 enters the condenser lens 103 and is condensed on the focal plane (E).

In the laser apparatus 101 shown in FIG. 7, when the spindle 202 is rotated about the rotation center axis (bb ′), the reflection surface (D) of the reflection mirror 201 fixed to the spindle 202 is also rotated to the rotation center axis (bb ′). ) To rotate.
When the reflecting surface (D) is rotated, the angle α is other than 90 degrees. Therefore, the incident angle and the reflecting angle of the laser beam 102 incident and reflected on the reflecting surface (D) are the same as those of the reflecting surface (D). Varies depending on the rotation angle. Therefore, the incident angle of the laser beam 102 incident on the condensing lens 103 changes, and the position of the condensing part s0 that is condensed on the condensing surface (E) changes. When the spindle 202 is rotated, the light condensing portion s0 rotates with a radius Δ represented by the following (Equation 1). f is the focal length of the condenser lens 103.
Δ = f × tan (2ε) (1)

The rotation center C0 of the condensing portion s0 is determined by the value of θ. When θ is 45 degrees, the rotation center of the condensing portion is the optical axis of the condensing lens 103 and the condensing light as shown in FIG. The center C0 of the condensing portion s0 when the angle θ is other than 45 degrees is the position of the intersection point C0 of the surface (E), and the position other than the intersection point of the optical axis of the condensing lens 103 and the condensing surface (E). It becomes.

  In the first embodiment, the central axis (aa ′) of the laser beam 102 emitted from the laser oscillator 101 coincides with the intersection of the rotation central axis (bb ′) of the spindle 202 and the reflecting surface (D). However, even if the center axis (aa ′) of the laser beam 102 does not coincide with the intersection of the rotation center axis (bb ′) of the spindle 202 and the reflecting surface (D), The condensing part s0 rotates.

In the first embodiment, the angle θ formed by the central axis (aa ′) of the laser beam 201 emitted from the laser oscillator 101 and the rotational central axis (bb ′) of the spindle 202 is 45 degrees. However, even if the angle θ is other than 45 degrees, the condensing portion s0 rotates.

  A system for processing the workpiece 1501 using the first laser apparatus 1000 shown in FIG. 7 is called a laser processing system 1001, and is shown in FIG. A second embodiment of the present invention will be described with reference to FIG.

  In the laser processing system 1001 shown in FIG. 8, the laser oscillator 101 is set such that the wavelength λ of the laser beam 102 is 1064 nm, the diameter d of the emitted laser beam 102 is 3 mm, and the repetition frequency R of the laser beam 102 is 400 kHz. And

  Further, the reflection mirror 201 and the spindle 202 are fixed so that α is 90.5 degrees. Further, the laser oscillator 101 and the reflection mirror 201 are installed so that the angle θ is 45 degrees.

  Further, the condenser lens 103 is installed at a position where the laser beam 201 emitted from the reflection mirror 201 is incident. A condenser lens having a focal length f of 20 mm is used.

  The workpiece 1501 is fixed to a workpiece moving stage (not shown) so that the laser beam 102 emitted from the condenser lens 103 of the first laser apparatus 1000 is incident on the surface of the workpiece 1501.

  Next, the workpiece moving stage (not shown) is moved to a position where the laser beam 102 enters the m point of the workpiece 1501.

  Next, the rotation speed P of the spindle 202 is set to 16000 rpm, and the spindle 202 is rotated. An electric motor or an air motor is desirable as the power that gives the spindle 202 rotational movement.

  Next, at the same time as the laser beam 102 is emitted from the laser oscillator 101, the workpiece moving stage (not shown) is linearly operated at a predetermined speed V to the position where the laser beam 102 is incident on the n point of the workpiece 1501. The speed V is set to 5 mm / second. When laser processing is performed up to n points, the laser oscillator 101 stops the emission of the laser beam 102.

Table 1 shows the processing conditions of the workpiece 1501 as processing conditions 1.

  FIG. 9 shows a locus 311 of the central point of the condensing portion s0 of the laser beam 102 incident on the workpiece 1501. In the second embodiment, the locus 311 of the central point of the condensing part s0 is spiral.

In order to form a continuous groove in the workpiece 1501, the condensing portion s0 incident on the workpiece 1501 needs to overlap another condensing portion.

When the focal length of the condensing lens 103 is f, the light diameter incident on the condensing lens is d, the wavelength of the laser light is λ, and the laser light is a Gaussian beam, the diameter ΦSP of the condensing portion s0 is It is given by (Equation 2).
ΦSP = 1.83 × λ × f ÷ d (Formula 2)

The processing condition 1 and the above (formula 1) and (formula 2) indicate that the condensing portion s0 overlaps, and a continuous groove is formed on the workpiece 1501.

FIG. 10 shows an appearance of a workpiece 1501 processed by the laser processing system 1001. The laser processed portion 1502 is a continuous groove with overlapping light converging portions.

  FIG. 11 is a cross-sectional view taken along the line BB of the processed portion 1502 of the workpiece 1501 shown in FIG. A processed portion 1502 is formed on the workpiece 1501, and the cross section of the processed portion has a trapezoidal shape.

  The area of the bottom surface of the processing portion 1502 is larger than the area of the bottom surface 107 of the laser processing portion 106 to which the condensing portion shown in FIG. 4 is fixed, and the concentration of external force and internal stress applied to the workpiece 1501 is reduced. Cracks are less likely to occur in the workpiece 1501, and the processing speed can be improved.

  Examples of the workpiece 1501 include materials such as tempered glass, silicon, sapphire, silicon carbide, gallium nitride, and a low-k material.

  Examples of power for rotating the spindle 202 include an electric motor such as a DC motor and an AC motor, and a pressure motor such as an air motor and a hydraulic motor.

DESCRIPTION OF SYMBOLS 101 Laser oscillator 102 Laser beam 103 Condensing lens 104 Condensing point 105 Work piece 106 Work part 107 Process part bottom face 108 Crack 201 Reflection mirror 202 Spindle 1000 1st laser apparatus 1001 1st laser processing system 1501 Work piece 1502 Machining part

Claims (5)

A laser oscillator that emits laser light, a reflection mirror that reflects the laser light, a spindle that can rotate around one rotation center axis, and a condensing lens that condenses the laser light reflected by the reflection mirror on a condensing portion The angle between the reflection surface of the reflection mirror and the rotation center axis is fixed at an angle other than 90 degrees.   2. The laser device according to claim 1, wherein the condensing portion is rotated by rotating the reflection mirror about the rotation center by rotating the spindle about the rotation center axis.   3. The laser device according to claim 2, wherein the laser beam emitted from the laser oscillator is incident on an intersection between the rotation center axis and a reflection surface of the reflection mirror.   3. The laser device according to claim 2, wherein the laser beam emitted from the laser oscillator is incident on a portion other than the intersection of the rotation center axis and the reflection surface of the reflection mirror. 5. The laser device according to claim 2, wherein the spindle is rotated by a pressure motor.