WO2020012771A1

WO2020012771A1 - Laser machining device, laser machining method, and production method for film-formation mask

Info

Publication number: WO2020012771A1
Application number: PCT/JP2019/018507
Authority: WO
Inventors: 齋藤　雄二; 平山　秀雄
Original assignee: 株式会社ブイ・テクノロジー
Priority date: 2018-07-09
Filing date: 2019-05-09
Publication date: 2020-01-16
Also published as: KR102644949B1; WO2020013122A1; JP7175457B2; DE112019003473T5; KR20210028650A; JPWO2020013122A1; TWI814859B; CN112384323B; CN112384323A; TW202005736A

Abstract

The present invention comprises: a laser optical system 1 that generates a line beam Lb; a shadow mask 2 that is arranged downstream of the laser optical system 1 in a light advancement direction and has provided therein a plurality of open windows that correspond to a plurality of opening patterns that are to be laser machined into a mask member 9; a projection lens 3 that projects an image of the shadow mask 2 onto the mask member 9; a movement mechanism 4 that makes the line beam Lb, which is radiated onto the shadow mask 2, move relative to the shadow mask 2 and the projection lens 3 in a direction that intersects the long axis of the line beam Lb; and a stage 5 that carries the mask member 9.

Description

Laser processing apparatus, laser processing method, and method of manufacturing film forming mask

The present invention relates to a laser processing apparatus, and more particularly, to a laser processing apparatus, a laser processing method, and a method for manufacturing a film forming mask that reduce the tact time in a laser processing step.

A conventional laser processing apparatus irradiates a shadow mask provided with a plurality of opening windows corresponding to a plurality of processing marks to be laser-processed on a workpiece with laser light, and a laser beam passing through the opening windows causes the laser beam to pass through the opening window. The above processing marks are laser-processed (for example, see Patent Document 1).

WO 2017/154233

However, in such a conventional laser processing apparatus, a processing mark is laser-processed on a predetermined region of the workpiece while irradiating the shadow mask with a plurality of shots of laser light, and when the processing is completed, the workpiece is placed. This is a so-called step-and-repeat method in which the stage is moved by a predetermined distance, and an operation of laser machining a processing mark in another region of the workpiece in the same manner as described above is repeated. Therefore, the time required to move the stage by controlling the acceleration and deceleration while securing the distance is much longer than the laser processing time, and it is difficult to reduce the tact time in the laser processing step. Therefore, there was a problem that the manufacturing cost of the processed product was increased.

Accordingly, it is an object of the present invention to provide a laser processing apparatus, a laser processing method, and a method of manufacturing a film forming mask which address such a problem and reduce the tact time in a laser processing step.

In order to achieve the above object, a laser processing apparatus according to the present invention includes a laser optical system that generates a line beam, and a plurality of laser optical systems that are disposed downstream of the laser optical system in the light traveling direction and are laser-processed on a workpiece. A shadow mask provided with a plurality of opening windows corresponding to processing marks, a projection lens for projecting an image of the shadow mask on the workpiece, and the shadow mask for projecting the line beam irradiated on the shadow mask A moving mechanism for moving the line beam in a direction intersecting the long axis of the line beam relative to the projection lens; and a stage for mounting and holding the workpiece.

Further, the laser processing method according to the present invention is a method of irradiating a line mask on a shadow mask provided with a plurality of opening windows corresponding to a plurality of processing marks to be laser-processed on a workpiece, and passing the laser beam through the opening window. A laser processing method for laser processing the processing mark on the workpiece using a beam, wherein the line beam irradiated on the shadow mask is used to form the shadow mask and an image of the shadow mask during laser processing. It moves in a direction intersecting the long axis of the line beam relative to a projection lens that projects onto a workpiece.

Further, the method for manufacturing a film forming mask according to the present invention is applicable to a plurality of opening patterns to be laser-processed on a mask member in which a resin film and a metal sheet made of a magnetic metal material provided with a plurality of through holes are laminated. A method of manufacturing a film forming mask, comprising: irradiating a line beam onto a shadow mask provided with a plurality of opening windows, and laser processing the opening pattern on the mask member by a laser beam passing through the opening windows. The line beam irradiated on the mask intersects the major axis of the line beam relative to the shadow mask and a projection lens that projects an image of the shadow mask onto the mask member during laser processing. To move in the direction of movement.

According to the present invention, the laser processing time of the predetermined region is determined by the moving speed of the line beam, unlike the related art which depends on the step moving time of the stage, and the moving speed of the line beam is substantially determined by the oscillation frequency of the laser. Since it is determined, laser processing that makes full use of the oscillation frequency of the laser can be performed. Therefore, the tact time of the laser processing step can be reduced, and the cost of the processed product can be reduced. In addition, since the workpiece is laser-processed while moving the line beam, the intensity distribution in the moving direction of the line beam is averaged and uniform, and a uniform processing mark with no excess or shortage can be formed.

It is a front view showing the schematic structure of one embodiment of the laser processing device by the present invention. It is a figure which shows the member for masks as a to-be-processed object, (a) is sectional drawing, (b) is a principal part expanded sectional view which shows the opening pattern which is a processing mark. FIG. 3 is a plan view showing a relationship between a line beam and a shadow mask. FIG. 4 is an explanatory diagram illustrating a configuration example of a moving mechanism. FIG. 3 is a block diagram illustrating a configuration example of a control device. 4 is a table comparing the laser processing method according to the present invention and the conventional method with respect to the processing time of laser processing under the same conditions.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a front view showing a schematic configuration of an embodiment of a laser processing apparatus according to the present invention. This laser processing apparatus irradiates a workpiece with a laser beam through a shadow mask to form a processing mark. The laser optical system 1, a shadow mask 2, a projection lens 3, a moving mechanism 4, , Stage 5 and control device 6.

Here, as shown in FIG. 2A, the workpiece is a resin film 7 made of, for example, polyimide or polyethylene terephthalate (PET) and a metal sheet 8 made of a magnetic metal material provided with a plurality of through holes 10. A case where the processing trace is an opening pattern 11 formed in a portion of the resin film 7 located in the through hole 10 as shown in FIG. 2B will be described. . In FIG. 2A, reference numeral 12 denotes a frame that supports the mask member 9.

メタル Instead of the resin film 7, a metal foil sheet having a thickness substantially equal to that of the resin film 7 (about 3 μm to about 10 μm) may be used. In this case, in order to form the opening pattern 11 on the metal foil sheet, an infrared laser beam is used, unlike ultraviolet rays described below.

The laser optical system 1 generates a laser beam L of a line beam Lb, and includes a laser light source 13, a front optical system 14, and a rear optical system 15 from the upstream side in the light traveling direction. .

The laser light source 13 emits laser light L having a wavelength in an ultraviolet region capable of ablating the resin film 7, and is, for example, an excimer laser or a YAG laser. The pre-stage optical system 14 includes a beam expander that expands the diameter of the laser light L emitted from the laser light source 13, a collimator lens that converts the expanded laser light L into parallel light, and an attenuator that adjusts the laser intensity. And a shutter for opening and closing the optical path of the laser light L, and has functions such as a beam profile check, a power monitor, and a beam position correction. Further, the rear optical system 15 includes a homogenizer for equalizing the intensity distribution of the laser beam L in the cross section and a cylindrical lens for converting the laser beam L having an enlarged diameter into a line beam Lb, for example. Have been. In FIG. 1, reference numeral 16 denotes a plane reflecting mirror.

シャ A shadow mask 2 is provided on the downstream side of the laser optical system 1 in the light traveling direction. As shown in FIG. 3, the shadow mask 2 is provided with a plurality of opening windows 17 corresponding to a plurality of opening patterns 11 to be laser-processed on the mask member 9 and branches the line beam Lb into a plurality of laser beams B. The mask member 9 is irradiated with a plurality of openings 17 formed by etching or the like on an opaque film such as chromium adhered to the surface of transparent glass. Alternatively, a plurality of opening windows 17 penetrating a metal sheet may be provided. In detail, the shadow mask 2 of the present invention is larger than the conventional shadow mask so as to cover a larger area than the processing area on the mask member 9 covered by the conventional shadow mask.

投影 A projection lens 3 is provided downstream of the shadow mask 2 in the light traveling direction. The projection lens 3 projects the image of the shadow mask 2 onto the mask member 9. In the present embodiment, the image of the opening window 17 of the shadow mask 2 is formed by the resin in the through hole 10 of the metal sheet 8. The image is projected on the film 7 by reducing it to 1/5.

As shown in FIG. 1, a moving mechanism 4 is provided so as to move the line beam Lb irradiated on the shadow mask 2 in a direction (Y-axis direction) intersecting with the long axis (X-axis) of the line beam Lb. Have been. The moving mechanism 4 moves the line beam Lb during laser processing at a constant speed (constant speed). For example, an air slider, a linear guide, or the like that moves the subsequent optical system 15 of the laser optical system 1 is provided. It is composed of a ball screw and the like. The projection lens 3 including the shadow mask 2 described below may be moved with respect to the line beam Lb. Here, the case where the line beam Lb is moved will be described.

FIG. 4 is an explanatory diagram showing an example of the configuration of the moving mechanism 4. The moving mechanism 4 has a mirror configuration inserted in the optical path on the output side of the post-stage optical system 15, and includes a fixed reflective mirror 19 having two outer reflective surfaces 18 intersecting at an angle of 90 ° with each other, It has two inner reflecting surfaces 20 that intersect at an angle of 90 °, and the two inner reflecting surfaces 20 maintain a parallel state with the two outer reflecting surfaces 18 of the fixed reflecting mirror 19, and And a movable reflective mirror 21 which is separated and approached in a direction connecting the intersections of the inner

reflective surfaces

18 and 20, and a movable planar reflective mirror 22 which bends the optical path of the output light reflected by the fixed reflective mirror 19 by, for example, 90 °. And is provided.

Then, the line beam Lb is moved on the shadow mask 2 by moving the movable flat reflecting mirror 22 along the optical axis of the incident light. In this case, the optical path length of the rear optical system 15 can be maintained by moving the movable reflection mirror 21 in synchronization with the movement of the movable flat reflection mirror 22. Specifically, when the movable flat reflecting mirror 22 is moved from left to right by a distance D in FIG. 4, the movable flat reflecting mirror 22 is moved so as to increase the distance between the movable reflecting mirror 21 and the fixed reflecting mirror 19 by D / 2. The reflection mirror 21 may be moved.

The moving mechanism 4 may be a combination of a galvano mirror or a polygon mirror and an fθ lens. Accordingly, the line beam Lb can be swung right and left by the galvanometer mirror or the polygon mirror, and the speed of the line beam Lb moving on the shadow mask 2 by the fθ lens can be made uniform.

ステージ A stage 5 is provided to face the projection lens 3. The stage 5 mounts and holds the mask member 9 and is configured to be movable in a two-dimensional plane orthogonal to the optical axis of the projection lens 3.

制御 A control device 6 is electrically connected to the laser light source 13, the pre-stage optical system 14, the moving mechanism 4 and the stage 5. The control device 6 controls each component to drive appropriately. As shown in FIG. 5, a laser light source controller 23, a pre-stage optical system controller 24, a moving mechanism controller 25, a stage controller 26, a memory 27, a calculation unit 28, and a central control unit 29.

Here, the laser light source controller 23 controls the turning on and off of the laser light source 13, the oscillation frequency, and the like. Further, the upstream optical system controller 24 controls the attenuator of the upstream optical system 14 so that the intensity of the laser beam L can be adjusted and controls the opening and closing of the shutter. Further, the moving mechanism controller 25 controls the moving mechanism 4 to control the moving speed of the line beam Lb on the shadow mask 2. The stage controller 26 controls the rotation angle of the stage 5 about the normal line at the center of the mounting surface of the stage 5, the moving direction, the moving speed, and the moving amount of the stage 5. Further, the memory 27 stores the oscillation frequency of the laser light source 13, the number of shots of laser processing, the moving speed of the line beam Lb, the moving speed and the moving amount of the stage 5, and the like. Further, the arithmetic unit 28 compares the moving speed of the line beam Lb read from the memory 27 with the actual moving speed of the line beam Lb, and controls the moving mechanism controller 25 so that the moving mechanism 4 is appropriately driven. At the same time, the moving speed and the moving amount of the stage 5 are read from the memory 27, and the stage controller 26 is controlled so that the stage 5 is appropriately driven by comparing with the actual moving speed and the moving amount of the stage 5. . The central control unit 29 controls each component in an integrated manner.

Next, a laser processing method using the laser processing apparatus configured as described above will be described. In particular, here, a method of manufacturing a film forming mask performed under the same processing conditions shown in FIG. 6 will be described in comparison with a conventional method.
First, as shown in FIGS. 1 and 2A, the resin film 7 of the mask member 9 is placed on the stage 5 in a state where the resin film 7 is in close contact with a flat glass substrate 30.

Next, alignment marks provided on the left and right sides of the center line in the Y-axis direction of the mask member 9 are photographed by an imaging camera (not shown), and the center line of the mask member 9 is moved to the stage 5 based on the photographed image. The rotation angle of the stage 5 is adjusted by the stage controller 26 so as to match the moving direction (Y-axis direction).

Next, the stage 5 is moved in the X-axis and Y-axis directions to adjust the irradiation position of the laser beam B to the laser processing start position of the mask member 9. At the same time, the optical system including the projection lens 3 is moved in the Z-axis direction and adjusted automatically so that the laser beam B is condensed on the resin film 7 by an auto-focus means (not shown). This completes the preparation for laser processing.

Next, the laser light source 13 is turned on through the laser light source controller 23 of the control device 6, and the shutter of the front optical system 14 is opened through the front optical system controller 24 to start laser processing. In this case, the laser light source 13 emits a laser beam L oscillating at, for example, 300 Hz and having a wavelength of 308 nm. The laser beam L emitted from the laser light source 13 is expanded in beam diameter by the pre-stage optical system 14, is converted into parallel light, and enters the post-stage optical system 15. The attenuator is adjusted in advance through the pre-stage optical system controller 24 so that the energy density of the laser light L is, for example, 400 mJ / cm ² .

The laser light L incident on the rear-stage optical system 15 is made uniform in laser intensity by a homogenizer constituting the rear-stage optical system 15, and then converted into one line beam Lb by, for example, a cylindrical lens. Irradiation.

At the same time, the moving mechanism 4 is driven under the control of the moving mechanism controller 25 of the control device 6 to move the rear optical system 15 at a constant speed in the Y-axis direction. As a result, the line beam Lb moves on the shadow mask 2 at a constant speed in the Y-axis direction.

In this case, the moving speed of the plurality of laser beams B passing through the shadow mask 2 and irradiating the mask member 9 has a predetermined area of the mask member 9, for example, a 3 mm width equal to the width of the laser beam B in the Y-axis direction. It is determined that the region is processed by laser irradiation of 60 shots (300 Hz). Therefore, in the embodiment of the present invention, the moving speed of the laser beam B is 15 mm / sec on the mask member 9. In the embodiment of the present invention, since the magnification of the projection lens 3 is 1/5, the moving speed of the line beam Lb on the shadow mask 2 is 75 mm / sec.

(4) The plurality of laser beams B that have passed through the shadow mask 2 are reduced to 1/5 by the projection lens 3 and are applied to an area of the mask member 9 having a width of 3 mm. Thereby, the resin film 7 located in the through hole 10 of the metal sheet 8 of the mask member 9 is ablated by the plurality of laser beams B, and a plurality of opening patterns 11 are formed.

At this time, the mask member 9 is laser-processed while the line beam Lb moves over the shadow mask 2 at a distance of 160 mm at the above-described speed of 75 mm / sec. The region width 29 mm in the direction is laser-processed, and a plurality of opening patterns 11 are formed.

When the predetermined area of the mask member 9 is laser-processed while moving the line beam Lb as described above, the shutter is closed by being driven by the pre-stage optical system controller 24, and the stage 5 is moved by the stage controller 26 in the predetermined direction. Is moved by a predetermined distance. Then, a new region of the mask member 9 is laser-processed in the same manner as described above, and the next plurality of opening patterns 11 are formed. In this case, the line beam Lb may be returned to the movement start position at a high speed and then moved in the same manner as described above, or may be moved in the opposite direction from the movement end position to the movement start position at a speed of 75 mm / sec. Is also good.

As described above, according to the present invention, the mask member 9 is laser-processed while moving the line beam Lb at a speed of 75 mm / sec, for example, at a distance of 160 mm. Therefore, the line beam required for one-step laser processing is performed. The moving time of Lb is 2.13 sec. As shown in FIG. 6, if the acceleration / deceleration time (total) at the start and stop of the movement of the line beam Lb is 1.0 sec, and the communication time between the control device 6 and the laser light source 13 is 0.5 sec. The processing time of one-step laser processing is 3.63 sec.

On the other hand, according to the conventional method, laser processing is performed in a state where the line beam Lb and the stage 5 are stopped. Therefore, in one-step laser processing, a region with a width of 3 mm in the Y-axis direction is irradiated with a laser beam L of 300 Hz. Done with shots. Therefore, the laser processing time of the processing region having a width of 3 mm is 0.2 sec. Further, as in the present invention, if the communication time between the control device 6 and the laser light source 13 is 0.5 sec, the processing time of one-step laser processing is 0.7 sec.

In the conventional method, the stage 5 is step-moved every time the laser processing of the processing area of 3 mm width is completed, and the laser processing of the next processing area of 3 mm width is performed. The laser processing of the region is performed by ten processing steps and nine step movements of the stage 5. Since the step moving time of the stage 5 is 1.70 sec, the processing time required for laser processing the same 29 mm (Y) width region as in the present invention by the conventional method is 22.3 sec in total, which is the present invention. This is much longer than the processing time of 3.63 sec.

Therefore, the processing time for laser processing the mask member 9 having the same area is much shorter in the present invention than in the conventional method, and the present invention shortens the tact time for manufacturing a film forming mask. be able to.

In particular, in the present invention, as the size of the shadow mask 2 increases and the processing area of one time increases, the processing time can be further reduced, and the tact time can be further reduced.

In the above description, an apparatus for manufacturing a film formation mask and a method for manufacturing a film formation mask have been described. However, the present invention is not limited to this. For example, an apparatus for laser annealing amorphous silicon on a semiconductor substrate, an exposure apparatus, and the like. The present invention can be applied to other laser processing apparatuses and laser processing methods.

DESCRIPTION OF SYMBOLS 1 ... Laser optical system 2 ... Shadow mask 3 ... Projection lens 4 ... Moving mechanism 5 ... Stage 7 ... Resin film 8 ... Metal sheet 9 ... Mask member (workpiece)
10: Through-hole 11: Opening pattern (processing mark)
17: Opening window Lb: Line beam B: Laser beam

Claims

A laser optical system for generating a line beam;
A shadow mask arranged on the downstream side in the light traveling direction of the laser optical system and provided with a plurality of opening windows corresponding to a plurality of processing marks to be laser-processed on the workpiece,
A projection lens that projects the image of the shadow mask onto the workpiece;
A moving mechanism for moving the line beam irradiated on the shadow mask relative to the shadow mask and the projection lens in a direction intersecting a long axis of the line beam;
A stage for mounting and holding the workpiece,
A laser processing apparatus comprising:
The laser processing apparatus according to claim 1, wherein the relative moving speed of the line beam is constant.
3. The laser processing apparatus according to claim 1, wherein the stage is configured to be movable in a two-dimensional plane orthogonal to an optical axis of the projection lens.
The workpiece is a mask member in which a resin film and a metal sheet provided with a plurality of through holes are laminated.
The processing mark is an opening pattern formed in a portion of the resin film located in the through hole,
The laser processing apparatus according to claim 1, wherein:
The workpiece is a mask member in which a resin film and a metal sheet provided with a plurality of through holes are laminated.
The processing mark is an opening pattern formed in a portion of the resin film located in the through hole,
The laser processing apparatus according to claim 3, wherein:
A line beam is irradiated on a shadow mask provided with a plurality of opening windows corresponding to a plurality of processing marks laser-processed on the workpiece, and the processing mark is formed on the workpiece by the laser beam passing through the opening windows. A laser processing method for laser processing,
The long axis of the line beam is irradiated with the line beam irradiated on the shadow mask relative to a projection lens that projects an image of the shadow mask and the shadow mask onto the workpiece during laser processing. A laser processing method characterized by moving in a direction intersecting with the laser beam.
7. The laser processing method according to claim 6, wherein the relative moving speed of the line beam is constant.
When the movement of the line beam on the shadow mask is completed, the workpiece is moved to another area on the workpiece, and the line beam is relatively moved with respect to the shadow mask and the projection lens. The laser processing method according to claim 6, wherein the processing mark is laser-processed while performing the laser processing.
The workpiece is a mask member in which a resin film and a metal sheet provided with a plurality of through holes are laminated.
The processing mark is an opening pattern formed in a portion of the resin film located in the through hole,
The laser processing method according to claim 6, wherein:
The workpiece is a mask member in which a resin film and a metal sheet provided with a plurality of through holes are laminated.
The processing mark is an opening pattern formed in a portion of the resin film located in the through hole,
9. The laser processing method according to claim 8, wherein:
A line beam on a shadow mask provided with a plurality of opening windows corresponding to a plurality of opening patterns corresponding to a plurality of opening patterns to be laser-processed on a mask member in which a resin film and a metal sheet made of a magnetic metal material provided with a plurality of through holes are laminated. A method of manufacturing a film forming mask for laser processing the opening pattern on the mask member by a laser beam that has passed through the opening window,
The long axis of the line beam is irradiated with the line beam irradiated on the shadow mask relative to a projection lens that projects an image of the shadow mask and the shadow mask onto the mask member during laser processing. A method of manufacturing a film-forming mask, wherein the film-forming mask is moved in a direction intersecting with the direction.
12. The method according to claim 11, wherein a relative moving speed of the line beam is constant.
When the movement of the line beam on the shadow mask is completed, the mask member is moved to another area on the mask member, and the line beam is relatively moved with respect to the shadow mask and the projection lens. The method according to claim 11, wherein the opening pattern is laser-processed while performing the laser processing.