JP2004114068A - Optical machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical machining device in which light outgone from an optical fiber can be entered into an aperture mask without reducing light intensity too much while preventing the damage to the aperture mask. <P>SOLUTION: In the optical machining device, which is provided with an YAG (Yttrium Aluminum Garnet) laser apparatus 1, an optical fiber 7 transmitting light emitted from the YAG laser apparatus 1, an aperture mask 64 partially shielding the light emitted from the optical fiber 7, and an imaging optical system 66 condensing the light passed through the opening 64a of the aperture mask 64, and imaging the same in the surface of a work W, the aperture mask 64 is arranged so as to be made away from the light emission edge 72 of the optical fiber 7. The device is also provided with a spread correction optical system 63 for suppressing the divergence of the light outgone from the optical fiber 7 and to be entered into the aperture mask 64. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical processing apparatus that processes a processing object by condensing light that has passed through an aperture mask and forming an image on the processing object.
[0002]
[Prior art]
Conventionally, as this kind of optical processing equipment, step index type laser light emitted from a laser as a light source is guided by an optical fiber, and the light passing through an aperture mask attached so as to be in contact with the light emitting end of the optical fiber is collected. Then, what forms an image with a predetermined magnification on a workpiece is known. In this optical processing apparatus, it is possible to process an object to be processed with a processing pattern corresponding to the aperture shape of the aperture mask. Further, since the light transmitted through the step index type laser beam is used, the energy distribution in the cross section orthogonal to the traveling direction of the light emitted from the optical fiber becomes uniform. Therefore, a processing pattern corresponding to the aperture shape of the aperture mask can be processed uniformly.
[0003]
[Problems to be solved by the invention]
Unlike the laser beam directly emitted from the laser, the light emitted from the optical fiber used in the conventional optical processing apparatus diverges with a wide divergence angle, and the light intensity rapidly decreases as the distance from the light emitting end of the optical fiber increases. I will do it. For this reason, the aperture mask is attached so as to be in contact with the light emitting end of the optical fiber, and the light emitted from the optical fiber is made incident on the aperture mask without reducing the light intensity. However, when the aperture mask is attached to the light emitting end of the optical fiber, there is a problem that the aperture mask may be damaged by the light emitted from the optical fiber.
[0004]
The present invention has been made in view of the above problems, and its object is to make light emitted from an optical fiber incident on an aperture mask without excessively reducing the light intensity while preventing damage to the aperture mask. It is to provide an optical processing apparatus capable of performing the above.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 includes a light source, an optical fiber that transmits light emitted from the light source, an aperture mask that partially blocks light emitted from the optical fiber, and the aperture. In an optical processing apparatus comprising an imaging means for condensing the light that has passed through the opening of the mask and forming an image on a workpiece, the aperture mask is disposed away from the light exit end of the optical fiber, and A light divergence suppressing unit is provided that suppresses the divergence of light that is emitted from the optical fiber and enters the aperture mask.
According to a second aspect of the present invention, in the optical processing apparatus of the first aspect, diffracted light blocking means is provided that blocks the diffracted light that is diffracted at the opening edge of the aperture mask and enters the imaging means. It is characterized by.
In the optical processing apparatus according to claim 1, by disposing the aperture mask away from the light emitting end of the optical fiber, the light having a high light intensity immediately after being emitted from the light emitting end of the optical fiber does not hit the aperture mask. To do. Then, by suppressing the divergence of the light emitted from the optical fiber and entering the aperture mask by the light divergence suppressing means, the intensity of the light incident on the aperture mask is not excessively reduced.
In the optical processing apparatus according to claim 2, the diffracted light which is diffracted at the edge of the aperture of the aperture mask and is about to enter the imaging means is blocked by the diffracted light shielding means, so that The diffracted light is not irradiated.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a laser processing apparatus that is an optical processing apparatus using a YAG (yttrium, aluminum, garnet) laser that is a solid-state laser will be described. Hereinafter, the ITO is partially removed from the glass using a laser processing apparatus on the workpiece W, which is a workpiece to be processed, in which a transparent conductive layer made of ITO (indium tin oxide) is formed on a substrate made of a glass plate or the like. A case where a transparent electrode pattern is formed will be described. The glass plate on which the transparent electrode pattern is formed is used for a PDP (plasma display panel), an LCD (liquid crystal display), a touch panel, and the like.
[0007]
FIG. 2 is a schematic configuration diagram of the entire laser processing apparatus according to the present embodiment. This laser processing apparatus mainly includes a YAG laser apparatus 1, a work holding apparatus 2, a work transfer apparatus 3, an XY table 4, a main controller 5 constituting a control means, a processing head apparatus 6, and a step index type optical fiber 7. It is configured. The XY table 4 is used as a relative moving means for relatively moving the laser light irradiation point with respect to the workpiece W and the workpiece W.
[0008]
FIG. 3 is a schematic configuration diagram showing the YAG laser device 1. The YAG laser device 1 includes a YAG laser oscillator 10 that is a light source, and a laser light incident guide portion 11 that guides laser light emitted from the YAG laser oscillator 10 to a light incident end of an optical fiber 7.
The YAG laser oscillator 10 includes a laser rod 12 that is a rod-shaped crystal of YAG to which an appropriate amount of Nd (neodymium) is added, and a laser chamber 12 that contains a pump for excitation thereof, along the optical path of stimulated emission light emitted therefrom. The front mirror 13 and the rear mirror 14 are arranged to face each other at a predetermined distance. A shutter 15 and a Q switch 16 are attached between the rear mirror 14 and the laser chamber 12. The front mirror 13 is a mirror having a reflectivity that allows transmission of a part of light, and is attached to the optical path of the laser chamber 12 with the center of the mirror surface facing it. The rear mirror 14 has a mirror surface capable of substantial total reflection, and is attached so as to face the front mirror 13. The shutter 15 blocks the optical path of the laser chamber 12. The Q switch 16 instantaneously increases the Q value of the resonator between the front mirror 13 and the rear mirror 14 and takes out a high-power laser pulse. Depending on processing conditions, this Q switch 16 may not be used.
The configuration of the YAG laser oscillator 10 is an example and is not limited to this. As another configuration, for example, there is a configuration using LD excitation.
[0009]
The laser beam incident guide unit 11 includes a laser beam expander 17 and a condenser lens 18. The laser beam emitted from the YAG laser oscillator 10 is expanded in beam diameter by the laser beam expander 17, and then is incident on the light incident end 71 (core portion end surface) of the step index type optical fiber 7 by the condenser lens 18. Be guided to. Laser light emitted from the light emitting end (core portion end face) of the optical fiber 7 is irradiated to the workpiece W on the XY table 4 through the machining head device 6 described later.
[0010]
In the step index type optical fiber 7, the core of the axial core portion has a refractive index larger than that of the cladding layer on the outer peripheral portion, and the refractive index changes on the step at the boundary between the core and the cladding layer. is there. When laser light is focused on the core of the step index type optical fiber 7, a plurality of light components incident at different angles of the laser light are transmitted through the core while being reflected multiple times at the boundary between the core and the cladding layer. Is done. As described above, the plurality of light components of the laser light are transmitted while being reflected in the core of the optical fiber 7 in a multiplexed manner, so that the energy density in the cross section of the laser light emitted from the light emitting end of the optical fiber 7 becomes uniform. ing.
[0011]
In the present embodiment, a configuration in which processing is performed using one laser beam emitted from one YAG laser oscillator 10 is employed, but a configuration in which processing is performed by irradiating a workpiece with a plurality of laser beams. May be. For example, the laser beam emitted from one YAG laser oscillator 10 may be divided into a plurality of pieces and irradiated onto the workpiece W via a plurality of optical fibers and a machining head device. Moreover, you may comprise so that the workpiece | work W may be irradiated with the some laser beam radiate | emitted from each of a some YAG laser oscillator.
[0012]
FIG. 4 is a plan view of the work holding device 2 as viewed from the upper side in FIG. The work holding device 2 plays a role of holding the work W on the work base 20 so that the position is not shifted during processing. A pair of fixed guides 21 and 22 and a pair of movable guides 23 and 24 are arranged on the work table 20 fixed to the XY table main body 41 shown in FIG. The fixed guides 21 and 22 and the movable guides 23 and 24 have a U-shape. Cam followers 21 a, 21 b, 22 a, 22 b, 23 a, 23 b, 24 a, 24 b that can turn the cylindrical surface are provided at the U-shaped tip portions, respectively. Since the cylindrical surfaces of these cam followers are in rolling contact with the workpiece end surface, the workpiece can be positioned more smoothly during positioning than when the guide is in sliding contact with the workpiece. When the workpiece W is set on the workpiece table 20, the workpiece W is pressed toward the fixed guides 21 and 22 by the movable guides 23 and 24, and the workpiece W is held on the workpiece table 20.
[0013]
The workpiece transfer device 3 is for mounting and removing a workpiece on the workpiece table 20. As shown in FIG. 2, the work upper surface is conveyed while being vacuum-sucked by a plurality of suction pads 31.
The XY table 4 mainly includes an XY table body 41 and an XY table controller 42 that controls the XY table body 41. The XY table body 41 is provided with the work holding device 2 as described above.
The main controller 5 controls the entire laser processing apparatus, and is connected to a YAG laser apparatus 1, a workpiece transfer apparatus 3, an XY table controller 42, and a processing head apparatus 6 described later.
[0014]
FIG. 5 is a side view showing a schematic configuration of a main part of the XY table 4 in the present embodiment.
The XY table 4 moves the work table 20 on which the work W is held with respect to the machining head device 6 in the X-axis direction (paper surface direction in the drawing) and the Y-axis direction (left-right direction in the drawing). The work table 20 moves in the X-axis direction with the work W placed thereon by driving the linear motor 43. During this movement, the work table 20 is guided by the guide 44 and moves linearly on the moving table 45 along the X-axis direction. On the other hand, similarly to the work table 20, the moving table 45 also moves linearly in the Y-axis direction with the work table 20 placed by driving a linear motor (not shown).
[0015]
A scale holding unit 47 that holds the linear scale 46 is fixedly disposed on the upper surface of the moving table 45. The scale direction of the linear scale 46 is parallel to the X-axis direction. On the other hand, a sensor holding part 49 to which a position detection sensor 48 is attached is fixed to the lower surface of the work table 20. The position detection sensor 48 is disposed so as to face the linear scale 46. As the position detection sensor 48, for example, a reflection type optical sensor can be used. In this case, an ON / OFF signal is output to the XY table controller 42 by a scale on the linear scale 46. The XY table controller 42 controls the driving of the linear motor 43 based on the signal, moves the workpiece W relative to the machining head device 6, and performs positioning in the X-axis direction. The same applies to the Y-axis direction.
[0016]
Next, the configuration of the machining head device 6 that is a characteristic part of the present invention will be described.
FIG. 1A and FIG. 1B are a front view and a side view of a processing head 60 provided in the processing head device 6, respectively. The processing head 60 includes a movable head portion 61 and a linear drive device 62 as a moving means for linearly moving the movable head portion.
The movable head unit 61 includes a fiber holding unit 70 that holds the tip of the optical fiber 7, a spread correction optical system 63 as a light divergence suppressing unit, an aperture mask 64, a partition plate 65 as a diffracted light shielding unit, and an imaging unit. The imaging optical system 66 and the like. The aperture mask 64 partially shields the light emitted from the optical fiber 7 to shape the cross-sectional shape of the laser light into a predetermined shape, and is disposed away from the light emitting end 72 of the optical fiber 7. . The spread correction optical system 63 is composed of a double-sided convex lens, a lens whose one surface is flat and the other surface is convex, and the like, and divergence of laser light that is emitted from the optical fiber 7 and enters the aperture mask 64. It suppresses. The partition plate 65 blocks diffracted light that is diffracted at the edge of the opening of the aperture mask 64 and enters the imaging optical system 66. The imaging optical system 66 focuses the laser light that has passed through the aperture of the aperture mask 64 and forms an image on the workpiece W. In the present embodiment, the magnification of the imaging optical system 66 is set to ½, but is not limited to this magnification.
[0017]
The linear drive device 62 is mainly composed of a linear motor 67, two linear guides 68, and a support base 69. The movable head unit 61 is moved in the horizontal direction in FIG. 1A (in the direction perpendicular to the paper surface in FIG. 1B) by driving the linear motor 67. At the time of this movement, the movable head portion 61 is linearly moved on the support base 69 by being guided by the linear guide 68. In the present embodiment, the movable head portion 61 is movable only in the direction guided by the linear guide 68.
[0018]
On the support base 69, a linear scale (not shown) similar to the XY table 4 described above is fixedly arranged. The scale direction of the linear scale is parallel to the linear guide 68. On the other hand, a position detection sensor similar to the above-described XY table 4 is fixed on the surface of the movable head portion 61 facing the support base 69. The position detection sensor is disposed so as to face the linear scale. As this position detection sensor, the same sensor as the XY table 4 described above can be used. In this embodiment, a reflective optical sensor is used. The position detection sensor outputs an ON / OFF signal based on the scale on the linear scale to the motor controller of the linear motor 67. The motor controller controls the driving of the linear motor 67 based on the signal, moves the movable head 61 linearly, and performs positioning in the moving direction.
[0019]
As shown in FIG. 6, the laser light L emitted from the light emitting end (core part end face) 72 of the optical fiber 7 has a predetermined shape after the spread correction optical system 63 suppresses the divergence of the laser light. The aperture mask 64 in which the opening 64a is formed is shaped into a predetermined shape. When the laser beam L passes through the aperture mask 64, diffraction of the laser beam occurs at the edge of the opening 64a of the aperture mask 64, but this diffracted beam Ld is blocked by the partition plate 65. Thus, the laser beam L blocked by the diffracted beam Ld is collected by the imaging optical system 66 and irradiated so as to form an image on the workpiece W on the XY table 4. By irradiation with the laser light L, the transparent conductive layer made of ITO (indium tin oxide) on the workpiece W is partially removed with a processing pattern corresponding to the shape of the opening of the aperture mask 64.
[0020]
FIG. 7 is an explanatory diagram of the slit processing for removing the ITO transparent electrode layer of the workpiece W in a line shape using the aperture mask 64 having the square opening 64a. As shown in the drawing, the processing is performed on the workpiece W by controlling the irradiation timing of the laser beam and the movement of the workpiece W so as to continuously irradiate the square irradiation spot P on the workpiece W while partially overlapping. Line-shaped slits 101 can be formed in the transparent electrode layer Wo.
[0021]
As described above, according to the present embodiment, by disposing the aperture mask 64 away from the light emitting end 72 of the optical fiber 7, the light having a high light intensity immediately after being emitted from the light emitting end 72 of the optical fiber 7 can be obtained. 64 is not hit. Therefore, damage to the aperture mask 64 due to the laser light emitted from the optical fiber 7 can be prevented.
Furthermore, the intensity of the light incident on the aperture mask 64 is prevented from excessively decreasing by spreading and suppressing the divergence of the light emitted from the optical fiber 7 and entering the aperture mask 64 by the correction optical system 63. . Accordingly, the laser light emitted from the optical fiber 7 can be incident on the aperture mask 64 without excessively reducing the intensity of the laser light L.
In addition, according to the present embodiment, the diffracted light Ld that is diffracted at the edge of the opening 64 a of the aperture mask 64 and is about to enter the imaging optical system 66 is blocked by the partition plate 65, so that the processing pattern on the workpiece W is changed. The periphery is prevented from being irradiated with the diffracted light. Therefore, it is possible to prevent unscheduled processing in which the transparent electrode layer around the processing pattern is removed by the diffracted light.
[0022]
In the above embodiment, the holding portion of the aperture mask 64 may be configured so that the aperture mask 64 can be rotated. In this case, as shown in FIG. 8, the irradiation timing of the laser beam, the rotation of the aperture mask 64, and the workpiece so that the fan-shaped irradiation spot P is continuously irradiated in a ring shape while partially overlapping the workpiece W. Process by controlling the movement of W. Thereby, the cylindrical slit 101 can be formed in the transparent electrode layer Wo on the workpiece W.
[0023]
Moreover, in the said embodiment, the aperture mask 64 (refer FIG. 9) which formed previously the opening 64a of the shape corresponding to the element shape pattern which comprises the process pattern which may be formed in the workpiece | work W in each of several divisions. Can also be used. In this case, the holding portion of the aperture mask 64 is configured so that the aperture mask 64 is moved in a plane perpendicular to the traveling direction of the laser light. Then, by moving the aperture mask 64 based on the processing data, the aperture mask 64 can be set so as to select an opening having a shape corresponding to the processing pattern and face the laser light passage region.
Alternatively, a plurality of aperture masks each having a light passage pattern corresponding to the element shape pattern may be used, and the aperture masks may be switched so as to face the laser light passage region.
[0024]
Moreover, although the said embodiment demonstrated the case where the process target (work W) was a glass plate in which the ITO transparent electrode layer was formed, a process target is not restricted to this. The present invention can also be applied to a case where a processing pattern made of a through hole is formed on a printing mask material, or a case where a processing pattern made of a recess is formed instead of a through hole.
Further, the present invention makes part of the resist film of the processing object soluble or hardly soluble in the solvent by irradiating the processing object having a resist film formed on the surface thereof with light that has passed through the aperture mask. The present invention can also be applied when forming an exposure pattern (processed pattern).
In addition, the present invention partially modifies the surface of the processing object by irradiating the processing object with light that has passed through the aperture mask (for example, modifying the surface to activate the surface by removing the oxide film). Quality) or marking on a workpiece, it can also be applied.
[0025]
In the above embodiment, the YAG laser is used as the light source. However, the present invention can also be applied to cases using other types of light sources. For example, as the light source, an ultraviolet laser such as a KrF excimer laser (wavelength: 248 nm) or an ArF excimer laser (wavelength: 193 nm), or a carbon dioxide gas laser (wavelength: 10.6 μm) can be used. In addition to the laser, a light source such as a mercury lamp or a synchrotron radiation light source (SOR light source) can be used. The optical members such as the optical fiber and the imaging optical system are selected according to the wavelength of the light source. For example, when an ultraviolet laser is used, an ultraviolet optical fiber or lens is used.
[0026]
Moreover, although the said embodiment demonstrated the case where the aperture mask in which the opening of the predetermined shape was formed was used, this invention forms a light-shielding pattern in transparent members, such as a glass plate, without forming an opening, for example. Thus, the present invention can also be applied when using an aperture mask in which a light passage pattern is formed.
[0027]
【The invention's effect】
According to the first and second aspects of the present invention, since the light having a high light intensity immediately after being emitted from the light emitting end of the optical fiber does not hit the aperture mask, the aperture mask is prevented from being damaged by the light emitted from the optical fiber. Can do. In addition, there is an effect that light emitted from the optical fiber can be incident on the aperture mask without excessively reducing the intensity of the light incident on the aperture mask. In particular, according to the second aspect of the present invention, it is possible to prevent the diffracted light diffracted at the edge of the aperture of the aperture mask from being irradiated to the peripheral portion of the processing pattern on the processing object. There is an effect that can be prevented.
[Brief description of the drawings]
FIG. 1A is a front view of a machining head provided in a machining head device of a laser machining apparatus according to an embodiment of the present invention.
(B) is a side view of the machining head.
FIG. 2 is a schematic configuration diagram of the entire laser processing apparatus.
FIG. 3 is a schematic configuration diagram of a YAG laser device of the laser processing apparatus.
FIG. 4 is a plan view of a work holding device of the laser processing apparatus.
FIG. 5 is a side view showing a schematic configuration of a main part of an XY table of the laser processing apparatus.
FIG. 6 is an explanatory diagram showing a state of laser light passing through a processing head of the laser processing apparatus.
FIG. 7 is an explanatory diagram of line-shaped slit processing.
FIG. 8 is an explanatory diagram of cylindrical slit processing.
FIG. 9 is a partial plan view of an aperture mask in which openings having a plurality of shapes are formed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 YAG laser apparatus 2 Work holding apparatus 3 Work transfer apparatus 4 XY table 5 Main controller 6 Processing head apparatus 7 Step index type optical fiber 10 YAG laser oscillator 11 Laser light incident guide section 60 Processing head 61 Movable head section 62 Linear drive Device 63 Spreading correction optical system 64 Aperture mask 64a Aperture 65 Partition plate 66 Imaging optical system 67 Linear motor 68 Linear guide 69 Support base 70 Fiber holding portion 71 Light incident end 72 of optical fiber Light exit end 101 of optical fiber Slit

Claims (2)

A light source, an optical fiber that transmits light emitted from the light source, an aperture mask that partially shields light emitted from the optical fiber, and light that has passed through an aperture of the aperture mask to collect light. In an optical processing apparatus provided with an imaging means for forming an image on the top,
Placing the aperture mask away from the light exit end of the optical fiber;
An optical processing apparatus, comprising: a light divergence suppressing unit that suppresses divergence of light emitted from the optical fiber and entering the aperture mask. The optical processing apparatus according to claim 1,
An optical processing apparatus, comprising: a diffracted light shielding means that diffracts light at the aperture edge of the aperture mask and shields diffracted light entering the imaging means.

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