JP2010230851A - Laser irradiation apparatus and laser irradiation method - Google Patents

Abstract

Laser irradiation apparatus and laser irradiation capable of processing an object to be processed without being affected by speckles and maintaining a constant value of energy supplied to a processing point on the object to be processed Providing a method.
A laser irradiation apparatus includes a laser oscillator 5 that irradiates a laser beam L and a single mode fiber 30, and has a variable number of turns or a radius of curvature. And a fiber 30 for transmission. The laser irradiation apparatus also includes an intensity controller 10 that controls the intensity of the laser light L in accordance with the number of turns of the fiber 30 or the radius of curvature.
[Selection] Figure 1

Description

  The present invention relates to a laser irradiation apparatus having a laser oscillator that irradiates laser light and a fiber that transmits laser light emitted from the laser oscillator.

  Conventionally, a processing table, a workpiece moving device for moving the processing object in the longitudinal direction of the processing object while holding one end of the processing object placed on the processing table, and a laser in the width direction of the processing object. There is known a laser irradiation apparatus including a processing head moving device that moves a processing head (see Patent Document 1).

  Such a laser irradiation apparatus requires an “alignment operation” for aligning the optical axes of an output mirror, a rear mirror, a YAG rod, and the like. Also, when the optical axis is shifted when the “alignment work” is insufficient or when environmental disturbances such as temperature changes and vibrations occur, the beam shape of the laser light applied to the object to be processed is a Gaussian distribution. In other words, the width of the laser light applied to the object to be processed changes, and the object to be processed cannot be processed in a uniform state.

  In this respect, when the laser beam is transmitted using a fiber, the above-described “alignment operation” is not required, and it has a strong resistance to environmental disturbances. For this reason, compared with the laser irradiation apparatus as described in Patent Document 1, it is possible to stabilize the laser beam irradiated to the object to be processed, and to improve the processing accuracy of the object to be processed.

JP-A-11-277285

  However, even when laser light is transmitted using such a fiber, if a multimode fiber is used, it will be affected by speckle, and high beam quality at the processing point cannot be ensured. .

  On the other hand, when single-mode fiber is used, high beam quality at the processing point can be secured without being affected by speckle, but transmission efficiency changes depending on the bending radius of the fiber, and the processing point energy can be kept constant. There is no problem.

  In this regard, especially in the case of a system that moves the processing optical system by taking advantage of the flexibility that is the greatest advantage of the fiber, the bending radius of the fiber changes every moment depending on the position of the processing optical system, so the energy supplied to the processing point There is a problem that fluctuates. As a matter of course, when the energy supplied to the machining point varies, the machining depth and the machining width vary, so that the machining quality deteriorates.

  The present invention has been made in consideration of such points, and can treat the object to be processed without being affected by speckles and can supply energy to the processing point on the object to be processed. An object of the present invention is to provide a laser irradiation apparatus and a laser irradiation method capable of maintaining a constant value.

The laser irradiation apparatus according to the present invention comprises:
A laser oscillator for irradiating laser light;
A fiber made of a single-mode fiber, having a variable number of turns or a radius of curvature, and transmitting a laser beam emitted from the laser oscillator;
An intensity control unit for controlling the intensity of the laser light according to the number of turns or the radius of curvature of the fiber;
May be provided.

In the laser irradiation apparatus according to the present invention,
The intensity control unit includes an attenuator for reducing the intensity of the laser light emitted from the laser oscillator according to the number of turns or the radius of curvature of the fiber, and an adjustment unit for adjusting the attenuation rate of the laser light by the attenuator. You may have.

In the laser irradiation apparatus according to the present invention,
The intensity control unit may include an adjustment unit that adjusts the intensity of laser light emitted from the laser oscillator in accordance with the number of turns of the fiber or the radius of curvature.

In the laser irradiation apparatus according to the present invention,
The strength controller stores in advance a relationship between the transmission efficiency of the fiber and the number of turns or the radius of curvature of the fiber, and stores the actual number of turns of the fiber or the radius of curvature and the stored number of turns of the fiber or the radius of curvature. While comparing, you may control the intensity | strength of the said laser beam.

The laser irradiation apparatus according to the present invention comprises:
You may further provide the winding part which became rotatable while the said fiber was wound.

The laser irradiation apparatus according to the present invention comprises:
It may have a conical shape or a truncated conical shape, and may further include a winding portion around which the fiber is wound.

The laser irradiation method according to the present invention comprises:
In a laser irradiation method using a laser irradiation apparatus having a laser oscillator and a fiber made of a single mode fiber and having a variable number of turns or a radius of curvature,
Irradiating laser light from the laser oscillator;
Transmitting the laser light emitted from the laser oscillator by the fiber, and
The intensity of the laser beam is controlled according to the number of turns or the radius of curvature of the fiber.

  According to the present invention, since the fiber is a single mode fiber, the object to be processed can be processed without being affected by speckle. Further, since the intensity of the laser beam is controlled according to the number of turns of the fiber or the radius of curvature, the energy supplied to the processing point on the object to be processed can be kept at a constant value.

The perspective view which shows the structure of the laser irradiation apparatus by the 1st Embodiment of this invention. 1 is an upper plan view showing a configuration of a laser irradiation apparatus according to a first embodiment of the present invention. The perspective view which shows the structure of the laser irradiation apparatus by the modification of the 1st Embodiment of this invention. The perspective view which shows the structure of the laser irradiation apparatus by the 2nd Embodiment of this invention. The perspective view which shows the structure of the laser irradiation apparatus by the modification of the 2nd Embodiment of this invention. The graph which showed the relationship between the transmission efficiency of the fiber memorize | stored in the memory | storage part of the laser irradiation apparatus by the 2nd Embodiment of this invention, and the curvature radius of a fiber.

First Embodiment Hereinafter, a first embodiment of a laser irradiation apparatus and a laser irradiation method according to the present invention will be described with reference to the drawings. Here, FIG. 1 to FIG. 3 are diagrams showing a first embodiment of the present invention.

  As shown in FIG. 1, the laser irradiation apparatus includes a laser oscillator 5 that irradiates laser light L and a single mode fiber 30, a fiber 30 that transmits the laser light L irradiated from the laser oscillator 5, and a fiber 30. A rotating reel (winding unit) 50 that is wound and rotatable, and an intensity control unit 10 that controls the intensity of the laser light L emitted from the laser oscillator 5 according to the number of windings of the fiber 30. I have. Note that the number of turns of the fiber 30 wound around the rotating reel 50 varies depending on the position of the processing optical system 40 described later. Further, a central portion (not shown) around which the fiber 30 is wound of the rotary reel 50 has a cylindrical shape.

  The intensity controller 10 is configured to reduce the intensity of the laser light L emitted from the laser oscillator 5. More specifically, as shown in FIG. 1, the intensity control unit 10 includes an attenuator 12 that reduces the intensity of the laser light L in accordance with the number of turns of the fiber 30, and a laser that is connected to the attenuator 12 and is driven by the attenuator 12. And an adjusting unit 11 that adjusts the attenuation factor of the light L. The attenuator 12 is disposed between the laser oscillator 5 and the fiber 30.

  Moreover, as shown in FIG. 1, the laser irradiation apparatus has a rotating reel (winding portion) 50 that is rotatable while the fiber 30 is wound around. The rotating reel 50 is connected to the adjusting unit 11, and the adjusting unit 11 is configured to detect data relating to the number of windings of the fiber 30.

  The adjustment unit 11 stores a relationship between the transmission efficiency of the fiber 30 and the number of turns of the fiber 30 in advance. Then, the adjustment unit 11 compares the detected data regarding the actual number of turns of the fiber 30 with the stored number of turns of the fiber 30, and based on the comparison result, determines the attenuation rate of the laser light L by the attenuator 12. Configured to adjust. Note that the relationship between the transmission efficiency of the fiber 30 and the number of turns of the fiber 30 may be calculated from a predetermined formula, or may be calculated in advance when the driving optical system is repeatedly and experimentally driven. You may obtain from the energy supplied to a process body.

  Note that the number of rotations of the fiber 30 wound around the rotary reel 50 is not limited to one or more times, and may be less than once. In this case, the adjustment unit 11 adjusts the attenuation rate of the laser light L by the attenuator 12 from the ratio of the fiber 30 wound (including the unwound state). By the way, the term “the number of windings” in the present application includes a ratio of winding less than one rotation.

  As shown in FIG. 1, between the attenuator 12 and the fiber 30, a collimator 20 that takes in the laser light L emitted from the laser oscillator 5 and emits it as parallel laser light L and the collimator 20 parallels the collimator 20. A shutter member 25 that switches between a transmitting state that transmits the laser beam L and a blocking state that blocks the laser beam L is disposed.

  As shown in FIG. 1, a processing optical system 40 that irradiates a solar cell substrate (object to be processed) 60 (see FIG. 2) with a laser beam L is connected to the end of the fiber 30. The processing optical system 40 is connected to an optical system driving unit 41 that drives the processing optical system 40 in the X direction (one of the horizontal directions). Note that the solar cell substrate 60 irradiated with the laser light L is held by a holding unit 45 that can move in the Y direction (a direction perpendicular to one of the horizontal directions) (see FIG. 2). In addition, the solar cell substrate 60 which is an example of a to-be-processed object has a board | substrate and the thin film provided on the said board | substrate (not shown).

  Next, the operation of the present embodiment having such a configuration will be described.

  First, the laser beam L is irradiated by the laser oscillator 5. And the laser beam L irradiated in this way is guide | induced into the collimator 20 through the attenuator 12 (refer FIG. 1).

  Next, the laser light L collimated by the collimator 20 reaches the shutter member 25, and the transmission state and the blocking state are switched by the shutter member 25 (see FIG. 1). That is, when the shutter member 25 is opened and opened, the laser beam L is transmitted. When the shutter member 25 is closed and closed, the laser beam L is blocked. It becomes.

  The laser light L that has passed through the shutter member 25 is transmitted through the fiber 30 including the single mode fiber 30 and irradiated from the processing optical system 40 toward the solar cell substrate 60 held by the holding unit 45 (see FIG. 1). ). Thus, while the solar cell substrate 60 is irradiated with the laser light L, the processing optical system 40 is moved in the X direction by the optical system driving unit 41, and the solar cell substrate 60 is moved in the Y direction by the holding unit 45. (See FIG. 2).

  As described above, since the processing optical system 40 is moved in the X direction by the optical system drive unit 41, the number of windings of the fiber 30 changes, so that the transmission efficiency changes every moment. Since the intensity control unit 10 controls the intensity of the laser light L emitted from the laser oscillator 5 according to the number of turns of the fiber 30, the energy supplied to the processing point can be maintained at a constant value.

  That is, according to the present embodiment, first, the adjusting unit 11 grasps the rotation state of the rotary reel 50 (understands how many times the rotary reel 50 has rotated), and the actual number of turns of the fiber 30 Is detected (see FIG. 1).

  Next, the adjustment unit 11 compares the detected data regarding the actual number of turns of the fiber 30 with the stored number of turns of the fiber 30.

  Next, the adjustment unit 11 adjusts the attenuation rate of the laser light L by the attenuator 12 based on the comparison result (the intensity of the laser light L emitted from the laser oscillator 5 is controlled) (see FIG. 1). ).

  As described above, according to the present embodiment, the intensity of the laser light L emitted from the laser oscillator 5 is controlled by the attenuator 12 according to the number of turns of the fiber 30, so that the fiber as in the present embodiment. Even when the method of moving the processing optical system 40 by utilizing the flexibility of 30 is used, the energy supplied to the processing point on the thin film of the solar cell substrate 60 can be kept at a constant value. For this reason, the processing depth of the thin film of the solar cell substrate 60 and the processing width of the thin film of the solar cell substrate 60 by the laser light L can always be kept constant, so that the solar cell substrate 60 can be processed with high quality. It will be possible.

  Moreover, in this Embodiment, since the adjustment part 11 has detected the winding number of the fiber 30 in real time, the attenuation factor of the laser beam L by the attenuator 12 will be adjusted at any time by the adjustment part 11, and a solar cell board | substrate. The energy supplied to the processing points on the 60 thin films can always be kept constant.

  Moreover, in this Embodiment, since the fiber 30 which consists of the single mode fiber 30 instead of the multimode fiber 30 is used, it is high in the processing point on the thin film of the solar cell substrate 60, without being influenced by speckle. The beam quality can be secured.

  By the way, in the present embodiment, the processing optical system 40 is moved in the X direction by the optical system driving unit 41 and the solar cell substrate 60 is moved in the Y direction by the holding unit 45. For example, a mode in which the processing optical system 40 is moved in both the X direction and the Y direction by the optical system driving unit 41 and the solar cell substrate 60 is fixed by the holding unit 45 may be used.

  In the above-described embodiment, the adjustment unit 11 has been described using the aspect in which the attenuation factor of the laser light L by the attenuator 12 is adjusted according to the number of turns of the fiber 30. However, the present invention is not limited to this. Instead, the adjustment unit 11 may be configured to adjust the intensity of the laser light L emitted from the laser oscillator 5 in accordance with the number of turns of the fiber 30 (see FIG. 3).

  Moreover, although the adjustment part 11 demonstrated using the aspect which detects the winding number of the fiber 30 by grasping | ascertaining the rotation condition of the rotation reel 50 above, it is not restricted to this. For example, the relationship between the number of turns of the fiber 30 (the number of turns on the rotating reel 50) and the position of the processing optical system 40 is measured in advance, and the control unit 11 determines the number of turns of the fiber 30 from the position of the processing optical system 40. You may use the aspect calculated.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. In the first embodiment shown in FIG. 1 to FIG. 3, the adjusting unit 11 adjusts the attenuation rate of the laser light L by the attenuator 12 according to the number of turns of the fiber 30, or is irradiated from the laser oscillator 5. The intensity of the laser beam L was adjusted. On the other hand, in the second embodiment shown in FIGS. 4 to 6, the adjusting unit 11 adjusts the attenuation factor of the laser light L by the attenuator 12 according to the radius of curvature of the fiber 30, or the laser oscillator. 5 for adjusting the intensity of the laser light L emitted from the light source 5. Other configurations are substantially the same as those of the first embodiment shown in FIGS.

  In the second embodiment shown in FIG. 4 to FIG. 6, the same parts as those in the first embodiment shown in FIG. 1 to FIG.

  In the present embodiment, the winding portion 50 ′ around which the fiber 30 is wound has a truncated cone shape, and the radius of curvature of the fiber 30 to be wound is variable. The adjustment unit 11 is configured to calculate the radius of curvature of the fiber 30 from the position of the fiber 30 at the winding portion 50 ′.

  The control unit 11 stores in advance a relationship between the transmission efficiency of the fiber 30 and the radius of curvature of the fiber 30 (for example, graph information as shown in FIG. 6). Then, the control unit 11 compares the data relating to the actual radius of curvature of the fiber 30 with the stored radius of curvature of the fiber 30, and adjusts the attenuation factor of the laser light L by the attenuator 12 based on the comparison result. (See FIG. 4), or adjust the intensity of the laser light L emitted from the laser oscillator 5 (see FIG. 5). For this reason, according to the present embodiment, as in the first embodiment, the energy supplied to the processing point can be made uniform, and the solar cell substrate (object to be processed) 60 can be formed with high quality. Can be processed.

  In the above description, the mode of calculating the radius of curvature of the fiber 30 from the position of the fiber 30 in the winding portion 50 ′ has been described. However, the present invention is not limited to this. For example, the relationship between the radius of curvature of the fiber 30 (the position of the fiber 30 in the winding portion 50 ′) and the position of the processing optical system 40 is measured in advance, and the control unit 11 determines the position of the fiber 30 from the position of the processing optical system 40. A mode of calculating the curvature radius of may be used.

  In the above description, the winding portion 50 ′ has been described using a truncated conical shape. However, the present invention is not limited to this, and the winding portion may have a conical shape.

5 Laser oscillator 10 Intensity control unit 11 Adjustment unit 12 Attenuator 20 Collimator 25 Shutter member 30 Fiber 40 Processing optical system 41 Optical system drive unit 45 Holding unit 50 Rotating reel (winding unit)
50 'winding part 60 solar cell substrate (object to be processed)
L Laser light

Claims (7)

A laser oscillator for irradiating laser light;
A fiber made of a single-mode fiber, having a variable number of turns or a radius of curvature, and transmitting a laser beam emitted from the laser oscillator;
An intensity control unit for controlling the intensity of the laser light according to the number of turns or the radius of curvature of the fiber;
A laser irradiation apparatus comprising:   The intensity control unit includes an attenuator for reducing the intensity of the laser beam emitted from the laser oscillator according to the number of turns or the radius of curvature of the fiber, and an adjustment unit for adjusting the attenuation rate of the laser beam by the attenuator. The laser irradiation apparatus according to claim 1, comprising:   2. The laser irradiation apparatus according to claim 1, wherein the intensity control unit includes an adjustment unit that adjusts the intensity of laser light emitted from the laser oscillator in accordance with the number of windings or the radius of curvature of the fiber. .   The strength controller stores in advance the relationship between the transmission efficiency of the fiber and the number of turns or the radius of curvature of the fiber, and stores the actual number of turns of the fiber or the radius of curvature and the stored number of turns of the fiber or the radius of curvature. The laser irradiation apparatus according to claim 1, wherein the laser light intensity is controlled and the intensity of the laser light is controlled.   The laser irradiation apparatus according to any one of claims 1 to 4, further comprising a winding portion that is rotatable while the fiber is wound thereon.   5. The laser irradiation apparatus according to claim 1, further comprising a winding portion that is formed in a conical shape or a truncated conical shape and on which the fiber is wound. In a laser irradiation method using a laser irradiation apparatus having a laser oscillator and a fiber made of a single mode fiber and having a variable number of turns or a radius of curvature,
Irradiating laser light from the laser oscillator;
Transmitting the laser light emitted from the laser oscillator by the fiber, and
The laser irradiation method, wherein the intensity of the laser light is controlled according to the number of turns or the radius of curvature of the fiber.

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