JP2007301610A - Laser beam machining method and laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining method and a laser beam machining apparatus capable of miniaturizing the laser beam machining device without any large floor area, enhancing the machining efficiency, and performing the effective compound machining by jointly using other light source. <P>SOLUTION: Galvano-motors 7, 8 having a pair of conventional mirror lenses 7-1, 8-1 for scanning X-direction and Y-direction and an fθ lens 9 are arranged on the optical passage of laser beams, and an object 11 is arranged on a conveyor moving in the X-axis direction or on an X stage. The object is machined by laser beams by controlling the galvano-motors 7, 8 synchronously with the movement of the object 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laser processing method and a laser processing apparatus such as a laser exposure marking device and a pattern processing device to which the laser processing method is applied.

  Conventionally, a laser processing apparatus using a laser beam has a method of processing a workpiece by moving the workpiece on an XY table in the XY direction without moving the laser beam, There is a method of processing a workpiece by fixing the workpiece, deflecting the laser beam using a galvano scanner or the like, and condensing the laser beam with an f · θ lens.

In general, whether the laser is a pulsed laser or a continuous light emitting laser, the laser emits light almost continuously in terms of processing time. Therefore, an acoustic element called AOM is used for high-speed control of laser beam emission and blocking. Laser processing is performed by controlling the used exposure shutter device to turn on and off the laser beam that reaches the processing surface.
Utility Model Registration No. 3095874 JP 11-271983 A

  However, since the former method performs processing by moving the workpiece in the XY direction, it requires a large floor area and is not suitable for miniaturization of a laser processing apparatus.

  Further, the latter method has a problem that it takes a long time to finish the processing of the processed portion because the workpiece is fixed and processed by moving the laser beam.

  An object of the present invention is to provide a laser processing method that contributes to downsizing of a laser processing apparatus without requiring a large floor area, improves processing efficiency, and enables combined processing by using another light source together. The object is to provide a laser processing apparatus.

  The present invention has been made to solve the above-mentioned problems. A first means of the present invention is a laser processing method for processing a workpiece using a laser beam, wherein the workpiece is moved in the X-axis direction. This is a laser processing method characterized in that processing is performed by deflecting the path of the laser beam in the direction of the next processing position in synchronization with the movement of the workpiece while moving.

  The second means of the present invention is a laser processing apparatus for processing a workpiece using a laser beam, while moving the workpiece on the conveyor or the X stage in the X-axis direction. The machining is performed by deflecting the path of the laser beam in the direction of the next machining position in synchronization with the movement of the workpiece.

  The third means of the present invention is to perform laser processing with a laser beam fixed to the workpiece in anticipation of a change in the processing dimension due to movement of the processing position within the movement time of the workpiece. The laser beam has a smaller condensing size than the above.

  According to a fourth means of the present invention, the cross-sectional shape of the laser beam is shaped into a circular shape or a shape other than a circular shape using an aperture.

  The fifth means of the present invention is characterized in that when the present invention is applied to a laser processing apparatus for exposure marking on a liquid crystal substrate, another light source for exposing the peripheral portion is used in combination.

  According to the first means of the present invention, as in the case of performing laser beam processing for liquid crystal substrate exposure marking, it is possible to simultaneously perform exposure of the ID portion and the peripheral portion, which have been conventionally performed in separate processes. Processing tact time can be remarkably shortened.

  According to the second means of the present invention, the laser beam processing time can be shortened, and it is possible to provide a laser processing apparatus such as a laser beam processing apparatus for liquid crystal substrate exposure marking with high efficiency.

  According to the third or fourth means of the present invention, exposure with a laser beam having an appropriate cross-sectional dimension can be performed.

  According to the fifth means of the present invention, there is provided a laser beam processing apparatus capable of simultaneously performing exposure of an ID portion and a peripheral portion, which has been conventionally performed in separate processes, and capable of significantly shortening the tact time of laser processing. Can be provided.

  Hereinafter, a basic embodiment and a laser processing method of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a basic configuration of a laser processing apparatus when a solid-state laser generator or a gas laser generator 1 (hereinafter referred to as a laser generator) is used. The laser beam emitted from the laser generator 1 is an acoustic element. The laser beam which is incident on the incident side aperture 2-1 of the exposure shutter device 2 called AOM using the beam and is emitted from the emission side aperture 2-2 of the exposure shutter device 2 is changed in its course by the total reflection mirror 3, and is incident on the incident side. After expanding the diameter of the laser beam by the expander lens 4 and the output side expander lens 5 and shaping it by the aperture 6, the mirror lens 7-1 of the galvano 7 for the X-axis direction of the galvano scanner and the galvano 8 for the Y-axis direction are used. The laser beam is bent to the vertical lower surface side by the mirror lens 8-1 and condensed by the f · θ lens 9, and the X stage 1 The exposure surface of the workpiece 11 placed at a fixed position on 0 is configured to be irradiated with a laser beam.

  In the present invention, for example, when marking a 2D code or the like, the workpiece 11 (for example, a liquid crystal substrate) is moved in the direction opposite to the X direction, and the galvano scanner constituting the galvano scanner is synchronized with this movement. The mirror lenses 7-1 and 8-1 of the motors 7 and 8 are controlled to deflect the laser beam to scan the position where the laser beam is irradiated, and the exposure shutter device 2 is controlled to interrupt the laser beam. Exposure marking is performed with a laser beam.

  The effect of the laser processing method according to the present invention is that, since the X-axis direction is the direction of the flow of the workpiece 11, no extra floor area is required in the Y direction, and the processing time is shortened by the movement time. It can be done.

  The method of moving the workpiece in the X-axis direction according to the present invention has an effect of making it possible to perform the following complex machining. That is, for example, when marking a two-dimensional code as an ID on the liquid crystal substrate 11 (workpiece), in the case of the conventional method, after marking all the two-dimensional codes, the unnecessary resist in the peripheral portion is exposed. Since the two steps of ID part exposure and peripheral part exposure were required, there was a problem that the X-axis direction dimension of the X stage on which the liquid crystal substrate is mounted and a problem that processing time was required. As shown in the example, the ID exposure and the peripheral exposure are simultaneously performed by providing another light source for the peripheral exposure, so that the entire exposure marking processing time can be remarkably shortened.

  FIG. 2 is a timing chart according to a conventional laser processing method in the case of exposing a 18 × 18 cell of a two-dimensional code. From the laser generator 1 in which the galvano mirror is deflected during the galvano position signal 1500 μs and the laser is oscillating. The emitted laser beam reaches the liquid crystal substrate 11 for 300 μs when the exposure shutter device 2 is turned on for 300 μs, and performs exposure marking of one cell.

  Similarly, in the next cell, the galvano mirror is deflected during 1500 μs to which the galvano position signal is applied, and the exposure shutter device 2 is turned on for 300 μs during the laser oscillation, so that the laser beam reaches the liquid crystal substrate 11 for 300 μs and 1 An individual cell is marked for exposure.

  When the exposure marking of all the cells of one two-dimensional code is completed, the next two-dimensional code is exposed in the same manner. After all the two-dimensional codes to be marked on the liquid crystal substrate 11 are exposed, the liquid crystal substrate 11 is moved to the X axis. It moves in the direction and is passed to the next process, where peripheral exposure is performed.

  In contrast to this conventional processing method, in the laser processing method according to the present invention, when the liquid crystal substrate 11 moves in the X-axis direction at a speed of 20 mm / sec, the cross section has a circular shape as shown in FIG. During the exposure with the laser beam, the liquid crystal substrate 11 is moved to the position of the circle 13 from the original position of 6 μm, that is, 20 mm / s × 0.3 ms = 0.006 mm. When the light is exposed in a round shape, as shown in FIG. 4, when the exposure diameter is 100 μm, the exposure diameter may be 6% smaller in the Y direction. In this way, the X-axis direction becomes 100 μm even if moved in 300 μs. Although the diameter in the Y direction remains 6% smaller, it does not hinder the function as a two-dimensional code.

  When the next cell is exposed, since the galvano mirror deflection waiting time of 1500 μs and the laser exposure time of 300 μs are moved by 1800 μs after the exposure of the first cell, the liquid crystal substrate moving speed is set to 20 mm / s. Then, 20 mm / s × 1.8 ms = 0.036 mm, that is, the position is moved from the position when the 36 μm liquid crystal substrate is fixed, so that the galvano is arranged so as to bring the laser focusing point to the next exposure position. If the deflection angle of the mirror is adjusted accordingly, it can be exposed at the correct position on the liquid crystal substrate. Thereafter, 18 × 18 cells can be exposed in the same manner.

  For example, in the case where the liquid crystal substrate is moved in the X direction in FIG. 6, the liquid crystal substrate is exposed at the position 17 in the X axis direction 5 and the Y direction 5 after the exposure at the position 16 in the X direction 7 and the Y direction 5. Is 20 mm / s and moves in the direction opposite to the X-axis direction, the interval between 16 and 17 is 200 μm, but after exposing 16, the exposure time is 1500 μs as a galvano mirror waiting time until 17 is exposed. Since the total time is 300 μs, the target position can be exposed by deflecting the galvanometer mirror so that the laser beam is condensed in the anti-X direction of 164 μm obtained by subtracting 36 μm from 200 μm.

  The same applies to the case where exposure is performed in the Y direction, and the same applies to the case where exposure is performed at locations separated in both XY directions.

  FIG. 7 shows an example of a two-dimensional code that has been exposed and marked in this manner. Note that 18 is a horizontal line of the two-dimensional code, and 19 is a vertical line of the two-dimensional code.

  In this example, since the laser beam is exposed over a wide area, the f · θ lens 9 and two galvanometer mirrors that oscillate the laser beam in the X and Y directions are used. Because of the relationship of the distortion of the galvanometer mirror that is scanned, a phenomenon occurs in which the light beam that is originally focused at the location indicated by x as shown in FIG. Thus, by measuring this graphic distortion in advance and controlling the laser beam to be focused at a position where the distortion is corrected, it is possible to expose at a more accurate position and mark a clean cell.

  FIG. 5 shows the exposure when the exposure marking shape is not a round shape but a square shape. Since the cross-sectional shape of the laser beam is round, if it is focused as it is, it becomes a round shape. Therefore, an aperture with a square hole is installed, and the shape when condensing on the exposure surface is a long rectangular shape that is long in the Y direction. In this case, when the liquid crystal substrate moves, the long square moves from 14 to 15. That is, the short side of the long square extends to form a quadrangular shape, and a rectangular exposure is performed.

  As is clear from the above description, in the laser processing method of the present invention, when marking a 2D code or the like on the exposure surface of the liquid crystal substrate 11, in order to mark the 2D code or the like while flowing the liquid crystal substrate in a direction opposite to the X direction, As described with reference to FIG. 6, a position to be exposed next is detected from a moving speed of the liquid crystal substrate by a position detection sensor (not shown) such as a rotary encoder, and a figure distortion correction amount or the like is detected. The laser processing is performed by deflecting the galvanometer mirror so that the laser beam is focused at that location.

  Although not shown in FIG. 1, the exposure of the peripheral portion of the liquid crystal substrate, which has been conventionally performed in separate steps, is performed by exposing the peripheral exposure device using an ultra-high pressure mercury lamp or UV-LED. In addition, it is possible to simultaneously process the peripheral portion as well as the ID portion while the liquid crystal substrate is moving, which has a great effect on shortening the tact time. Further, since the system is not moved in the Y direction, the area of the apparatus can be reduced.

  In FIG. 1, since a solid laser or a gas laser is used as the laser beam generator 1, high-speed switching is performed using the primary light by the exposure shutter device 2. When an LD (laser diode), which is a semiconductor laser, is used, since the LD rises quickly, switching can be performed by controlling the laser power supply, so that the exposure shutter device 2 is not necessary.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 9 is a perspective view showing a configuration for exposing an ID portion in a laser processing apparatus for two-dimensional code marking when a solid-state laser generator or a gas laser generator is used as the laser generator 21. The structure for exposing the portion and the portion not related to the essence of the invention are not shown.

  In FIG. 9, 22 is a main controller with a built-in CPU, 23 is a keyboard, 24 is a monitor, the main controller 22 gives a control signal to the scanner control device 25 based on an instruction from the keyboard 24, and the scanner control device 25 is a laser power source 26. Is activated, the laser generator 21 is operated to emit a laser beam, and the galvano scanner 27 is driven.

  The laser beam emitted from the laser generator 21 is an exposure shutter device 28 called AOM, a total reflection mirror 29, an incident side expander lens 30, an emission side expander lens 31, a laser beam shaping aperture 32, a galvano scanner 27, and f · θ. The light passes through the lens 33 and is irradiated onto the liquid crystal substrate 35 installed at a fixed position on the X stage 34.

  The exposure shutter device 28 is configured to be turned on and off by the control signal from the main controller 22 via the scanner control device 25 and the AOM control device 36 to intermittently laser the laser beam.

  Reference numeral 37 denotes a CCD camera as an edge sensor for the liquid crystal substrate 35, which detects whether or not the liquid crystal substrate 35 is in the correct position. The detection signal of the CCD camera 37 is transmitted to the main controller 22 via the image checker 38, and the state of the liquid crystal substrate can be monitored by the monitor 24.

  When it is detected by the detection signals of the CCD cameras 37 and 37 that the liquid crystal substrate 35 is not in the correct position on the X stage 34, a mechanism (not shown) is operated based on the detection signal and moved to the correct position. When it is detected that it is in the position, it is configured to be fixed on the X stage 34 by a known suction device (not shown).

  The laser beam scanning start position and end position are detected by the laser beam position detection sensors 39 and 39, and the detection signals are transmitted to the scanner controller 25 and the main controller 22 via the scanner controller 25.

  On the other hand, the X stage 34 is driven and controlled in the X axis direction by an X axis direction drive motor 42 via a PLC (programmable logic controller) 40 and a motor driver 41 in response to a command signal from the main controller 22, and the X axis of the X stage 34 is controlled. The moving speed or moving amount of the direction is detected by a position detection sensor 43 using a rotary encoder, a photo sensor, etc., and the detection signal is transmitted to the main controller 22 via the PLC 40 and the PLC 40, and then the laser beam is transmitted to the next. It is used as information for calculating which direction and which position to move.

  In the figure, 44 is a laser power sensor, and its detection signal is transmitted to the main controller 22 via the scan control device 25. When the actual light amount of the laser beam is not the light amount set by the keyboard 23, the scanner control device The laser light source 26 is controlled via the control unit 25 so that the light amount of the laser beam becomes the set light amount.

  The apparatus for exposing the ID portion according to the present invention described above is not a method of marking with the galvano scanner 27 with the liquid crystal substrate 35 fixed as in the conventional apparatus, but the liquid crystal substrate 35 is moved in the X-axis direction. In order to mark the next position with a laser beam, marking is then performed with a laser beam from the moving speed or moving amount of the liquid crystal substrate and the figure distortion correction information described in paragraph [0031]. The position is calculated by the main controller 22 and the galvano scanner 27 is driven.

  The effect of adopting such an X-stage moving method is that, as will be described below, a liquid crystal substrate 35 on which a two-dimensional code or the like conventionally marked in the next process is marked by using a peripheral exposure apparatus together. Simultaneous exposure (simultaneous processing) of the peripheral portion of the film becomes possible, and the marking time can be remarkably shortened, which greatly helps to improve productivity.

  FIG. 10 is a perspective view mainly illustrating the peripheral exposure apparatus of the first embodiment for easy understanding, and 45a and 45b are UV lamps for the peripheral exposure apparatus whose arrangement in the Y direction can be adjusted by a lead screw or the like. Y stage equipped with 46a and 46b (which may be LED), 47-1 and 47-2 are UV light quantity sensors, 48 is the position control of UV lamps 46a and 46b, and the light quantity of the UV lamps 46a and 46b is detected. This is a peripheral exposure control controller for controlling the light quantity of the UV lamp to an appropriate value.

  The peripheral portion exposure control controller 48 is connected to the main controller 22, and the main controller 22 controls the position control of the UV lamps 46 a and 46 b on the Y stages 45 a and 45 b and the light quantity and lighting control of the UV lamps 46 a and 46 b. Is configured to

  Accordingly, as shown in FIG. 10, the markings on both side lines 35 a and 35 b around the liquid crystal substrate 35 can be performed simultaneously with the marking of the ID portion during the movement of the liquid crystal substrate 35.

  Conventionally, for example, as shown in FIG. 11, when marking an ID portion P and peripheral lines 35a and 35b on a liquid crystal substrate 35, the ID portion P is first placed on the X stage 34 or the liquid crystal substrate 35 fixed on the conveyor. Was then marked with a laser beam, and then the X stage 34 or conveyor was moved to mark the peripheral lines 35a, 35b with fixed UV lamps 46a, 46b or LEDs.

  Therefore, in the conventional method in which the ID portion P and the peripheral lines 35a and 35b are separately marked, the exposure time for marking the peripheral portion becomes longer as the liquid crystal substrate becomes larger, and the tact time becomes longer. There was a problem.

  In the present invention, since the ID portion P is marked while moving the liquid crystal substrate 35, the control of the galvano scanner 27 is more complicated than before, but the moving speed or movement of the moving liquid crystal substrate 35 as described above. The amount is detected, and based on the information, the galvano scanner 27 is controlled to scan the laser beam, and the UV lamps 46a and 46b for peripheral exposure using UV lamps or LEDs are used together as shown in FIG. By performing the marking of the ID part P and the marking of the peripheral lines 35a and 35b at the same time, the tact time can be greatly shortened.

  FIG. 12 is a block diagram showing the connection of the control system of the first embodiment according to the present invention when a solid-state laser generator or a gas laser generator is used as the laser generator 21.

  FIG. 13 shows the marking of the liquid crystal substrate 35 shown in FIG. 11, and after marking the ID part P and the peripheral lines 35a and 35b in the X direction by the marking device shown in FIGS. It is a perspective view which shows the structure of the different Example comprised so that marking of the surrounding lines 35c and 35d could be performed, and abbreviate | omitting illustration about the detailed structure for marking ID part P for convenience of explanation is there.

  45c and 45d are Y stages equipped with UV lamps 46c and 46d (or LEDs may be used) for a peripheral exposure apparatus whose arrangement in the Y direction can be adjusted by a lead screw or the like, 43-3 and 43-4 are position detection sensors, 47 Reference numerals -3 and 47-4 denote UV light quantity sensors, which are connected to the main controller 22 via the controller 48 '.

  The peripheral lines 35c and 35d in the Y direction are moved to the position shown in the drawing after the marking of the ID part P and the peripheral lines 35a and 35d is finished, and then the UV lamp 46c, 46d is moved in the Y direction to mark the peripheral portions 35c and 35d in the Y direction.

  Therefore, according to this embodiment, the exposure marking of the liquid crystal substrate 35 illustrated in FIG. 11 is first performed by the movement of the liquid crystal substrate 35 set on the X stage 34 in the X-axis direction. The lines 35a and 35b are marked at the same time, and after the marking is completed, the peripheral lines 35c and 35d are marked in the Y direction, which is more efficient than the case where the conventional method is adopted. Marking can be performed and productivity can be improved.

  FIG. 14 is a block diagram showing connection of a control system according to the second embodiment of the present invention when a solid-state laser generator or a gas laser generator is used as the laser generator.

  When an LD, which is a semiconductor laser, is used as the laser generator 21, as described in paragraph [0035], since the LD rises quickly, switching can be performed by controlling the laser power source. The exposure shutter device 28 and the AOM control device 36 in FIG. 10 and FIG. 13 are unnecessary and can be omitted.

  As described above, the description has been made in relation to the two-dimensional code marking device for a liquid crystal substrate. However, the present invention can be applied to a laser processing device such as printed circuit board drilling.

The perspective view which shows the basic composition of the laser processing apparatus which concerns on this invention. The timing chart by the conventional laser processing method in the case of exposing 18x18 cell. Explanatory drawing which shows the change of the laser beam of a cross section in this invention. The figure which shows the relationship with the diameter of a Y direction when the diameter of the exposure of the X-axis direction of a laser beam is 1 micrometer in this invention. In the present invention, a cross-sectional view of a laser beam necessary for exposure of a square having a side of 100 μm. Explanatory drawing about the deflection | deviation of the laser beam in this invention. The figure which shows an example of a two-dimensional code. The figure which shows the distortion characteristic of f * theta lens accompanying the operation | movement of a galvano scanner in the case of marking a two-dimensional code. The perspective view which shows the structure for exposing the ID part in Example 1 of this invention. 1 is a perspective view mainly illustrating a peripheral exposure apparatus in Embodiment 1 of the present invention. FIG. The figure which shows the example of marking of a liquid crystal substrate. The block diagram which shows the connection of the control system of Example 1 which concerns on this invention. The perspective view which mainly drew the peripheral part exposure apparatus of Example 2 which concerns on this invention. The block diagram which shows the connection of the control system of Example 2 which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,21 Laser generator 2,28 Exposure shutter device 3,29 Total reflection mirror 4,30 Incident side expander lens 5,31 Outgoing side expander lens 6,32 Aperture 7,8 Galvano motor 9,33 f · θ lens 10, 34 X stage 11 Work piece 12, 13 Circular laser beam cross section 14, 15 Rectangular laser beam cross section 16, 17 Laser beam exposure position 18 Two-dimensional code horizontal line 19 Two-dimensional code vertical line 22 Main controller 23 Keyboard 24 Monitor 25 Scanner control device 26 Laser power supply 27 Galvano scanner 35 Liquid crystal substrate 36 AOM control device 37 CCD camera 38 Image checker 39 Laser beam position detection sensor 40 PLC
41 Motor driver 42 X-axis direction drive motor 43 Position detection sensor 44 Laser power sensors 45a to 45d Y stages 46a to 46d UV lamps 47-1 to 47-4 UV light quantity sensor 48 Controller P ID section

Claims (5)

  In a laser processing method of processing a workpiece using a laser beam, while moving the workpiece in the X-axis direction, the laser beam is synchronized with the movement of the workpiece in the direction of the next processing position. A laser processing method comprising performing processing by deflecting a path of a laser beam.   In a laser processing device that uses a laser beam to process a workpiece, the workpiece on the conveyor or X stage is moved in the X-axis direction while the laser beam is synchronized with the movement of the workpiece and then processed. A laser processing apparatus for performing processing by deflecting a path of a laser beam in a direction of a position to be processed.   The laser beam condensing dimension is made smaller than when laser processing is performed with the laser beam fixed to the workpiece in anticipation of changes in the machining dimension due to movement of the machining position within the movement time of the workpiece. The laser processing apparatus according to claim 2.   4. A laser processing apparatus according to claim 2, wherein the cross-sectional shape of the laser beam is shaped into a circular shape or a shape other than a circular shape using an aperture.   5. The laser processing apparatus for exposure marking of a liquid crystal substrate according to claim 2, wherein a light source for exposing the peripheral portion is used in combination.

Images