JP2011083795A - Laser beam machining apparatus and laser beam machining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve machining position accuracy in the laser beam machining for forming fine machining traces in the set arrangement. <P>SOLUTION: A controller outputs the output command of the pulse train signal to a pulse signal supply device at time t3 at which the machining start position D is detected. Thus, the pulse signal supply device outputs the pulse train signal to a laser beam drive circuit, and the laser beam drive circuit outputs the drive signal corresponding to the pulse train signal to a laser beam source. Then, a delay signal generation circuit detects the delay (the timing deviation Dev) from the time t3 at which the machining start position D is detected to time t4 at which the laser beam of the machining intensity is actually irradiated. The controller sets the time width Lt of the low level signal at the second period in the pulse train signal by the timing deviation Dev. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a laser processing apparatus and a laser processing method for forming a processing mark such as a pit by irradiating a processing object with laser light condensed by an objective lens.

  Conventionally, a processing trace is formed on a processing target by irradiating the processing set position with the laser light while changing the relative position between the laser beam focused by the objective lens and the processing target in the X direction and the Y direction. A laser processing apparatus that performs such a process is known, for example, from Patent Document 1. Such a laser processing apparatus can perform processing as desired by appropriately controlling the irradiation position of the laser beam.

Japanese Patent Laid-Open No. 8-118061

  When forming nano-order minute processing traces (pits or reaction traces for forming pits) on the surface of the workpiece, increase the movement accuracy of the moving mechanism that moves the laser beam irradiation position in the XY direction. One condition is to emit laser light at a predetermined XY position. However, no matter how much the moving mechanism with high movement accuracy and position detection accuracy is used, there is a problem that the actually formed machining trace is displaced from the set position. The inventor has found that this cause is due to a time delay from when the set position where the laser beam should be emitted is detected until the laser beam is actually emitted. Hereinafter, this reason will be described.

  In the laser processing apparatus, a digital signal representing the position of the stage is input to a controller (microcomputer) every time the stage moves a minute distance. When the controller determines that the moving position of the stage is the processing start position based on the input position signal, the controller outputs a light emission command for emitting pulsed laser light to the pulse signal supply device. The pulse signal supply device uses a light emission command output from the controller to send a high-level signal for emitting laser light with processing intensity to a laser light source via a laser drive circuit and a low-level signal for emitting laser light with non-processing intensity. And a light emission signal that alternately switches at a constant cycle. As a result, laser light having a processing intensity and laser light having a non-processing intensity are alternately emitted from the laser light source at a constant period, and processing marks are formed at a constant interval.

  FIG. 15 is a signal waveform diagram showing the operation timing. In the figure, (a) is a position detection signal input to the controller, (b) is a light emission command signal output from the controller to the pulse signal supply device, (c) is a light emission signal input to the laser light source, (d). Is a waveform representing the output of the emitted laser beam.

  As can be seen from this figure, there is a slight time delay Dev between time t1 when the stage position becomes the processing start position and time t2 when the laser beam having the processing intensity is actually emitted. This time delay Dev is 1) a time delay from when the position detection signal is input to the controller until it is determined that the controller has reached the machining position and a light emission command for laser light is output, and 2) a pulse signal supply device 3) Due to the time delay from when the controller receives the light emission command until the light emission signal is output to the laser light source. is there. For this reason, as shown in FIG. 16, the processing trace Pit (solid line portion) formed on the processing object is shifted from the processing setting position indicated by the broken line. In this case, the direction of deviation is the moving direction of the laser light irradiation position. For this reason, for example, the laser beam irradiation position is reciprocated in the X direction and is fed and moved in the Y direction at both ends of the reciprocating movement in the X direction. However, since the shift directions in the adjacent machining rows are opposite to each other, the machining trace Pit cannot be formed in such an arrangement.

  In manufacturing an LED substrate or a liquid crystal substrate, it is required to form nano-order processing traces on a substrate surface in a square shape or a hexagonal fine shape by irradiation with a laser beam. As described above, when the arrangement of the processing traces deviates from a square shape or a hexagonal close-packed shape, the quality of the element decreases as the deviation increases.

  The present invention has been made to cope with the above-described problem, and an object of the present invention is to improve processing position accuracy in laser processing that forms a fine processing trace in a set arrangement.

  In order to achieve the above object, a feature of the present invention is that a laser beam emitted from the laser light source to a workpiece to be processed set on the stage has a stage for setting the workpiece and a laser light source. By changing the relative position between the processing head that collects and irradiates light with an objective lens, and the processing head and the stage, the irradiation position of the laser beam on the processing object is orthogonal to the X direction and the X direction. Setting for the laser light source, moving means for moving in the Y direction, moving position detecting means for detecting the relative X-direction position and Y-direction position of the processing head and the stage, which are changed by the moving means, A light emission signal supply means for supplying a light emission signal for emitting a laser beam of a specified intensity, and a moving beam in which the irradiation position of the laser light on the workpiece is preset. A movement control means for controlling the movement means based on a relative position between the processing head and the stage detected by a movement position detection means, and the movement control means When controlled, the processing setting position is irradiated with laser light having a processing intensity based on the irradiation position of the laser beam detected by the moving position detecting means, and the processing setting position is different from the processing setting position. In the laser processing apparatus comprising a laser light irradiation control means for outputting a light emission signal supply command to the light emission signal supply means so that intense laser light is emitted, the movement position detection means is preset When a light emission signal supply command for emitting laser light having the processing intensity is output to the light emission signal supply means at the timing when the set position is detected. A timing deviation detecting means for detecting a timing deviation from a timing at which the set position is detected to a timing at which the laser beam having the processing intensity is emitted from the laser light source, and the light emission based on the detected timing deviation. By adjusting the time width of the light emission signal that causes the signal supply means to emit laser light having non-processing intensity, the timing at which the light emission signal for emitting laser light having processing intensity is supplied to the laser light source is adjusted. And a light emission signal supply timing adjusting means.

  In the laser processing apparatus of the present invention, the moving means changes the relative position between the stage on which the processing target is set and the processing head, and moves the irradiation position of the laser light on the processing target in the X direction and the Y direction. The movement position detection means detects the relative X direction position and Y direction position between the machining head and the stage. Then, the movement control means controls the movement means so that the irradiation position of the laser beam on the object to be processed moves along a preset movement route based on the detected relative position between the machining head and the stage. . Here, the irradiation position of the laser beam is a position where the objective lens can condense and irradiate the laser beam, and does not ask whether the laser beam is actually irradiated to the workpiece.

  The laser light irradiation control means performs processing based on the relative position between the processing head and the stage detected by the movement position detection means when the laser light irradiation position is moving along a preset movement route. Supplying the emission signal to the emission signal supply means so that the setting position is irradiated with the laser beam having the processing intensity, and the position different from the processing setting position is irradiated with the laser beam having the non-processing intensity. Outputs a command. When the light emission signal supply means receives a light emission signal supply command, the light emission signal supply means supplies a light emission signal for emitting laser light having a set intensity to the laser light source. The intensity of the laser light is switched at least between the processing intensity and the non-processing intensity by a light emission signal supplied to the laser light source. The laser beam having a processing intensity is a laser beam having an intensity capable of forming a processing mark on the object to be processed. The laser beam having a non-processing intensity is an intensity that does not change the object to be processed (from the processing intensity). (It is also weak). If the light emission signal supplied from the light emission signal supply means is a light emission signal that emits a laser beam having a processing intensity, the laser light source emits a laser beam having a processing intensity for the time during which the light emission signal is supplied. Further, if the light emission signal supplied from the light emission signal supply means is a light emission signal that emits laser light having non-processing intensity, laser light having non-processing intensity is emitted only for the time when the light emission signal is supplied. Therefore, by combining the laser beam intensity for processing and non-processing, it is possible to form processing traces at arbitrary intervals on the surface of the processing target.

  During such laser light irradiation control, if a light emission signal supply command for emitting laser light of processing intensity is output to the light emission signal supply means at the timing when the processing set position is detected, the actual processing is performed from the laser light source. Due to the time delay until the laser beam having the required intensity is emitted, particularly when a nano-order machining trace is formed, the machining trace deviates from the machining setting position. Therefore, in the present invention, a timing shift detection unit and a light emission signal supply timing adjustment unit are provided. The timing deviation detection means is set when a light emission signal supply command for emitting a laser beam of processing intensity is output to the light emission signal supply means at a timing when the moving position detection means detects a preset set position. A timing shift is detected from the timing at which the position is detected to the timing at which the laser beam having the processing intensity is emitted from the laser light source. Then, the light emission signal supply timing adjusting means changes the time width of the light emission signal that causes the light emission signal supply means to emit the non-processing intensity laser light based on the detected timing deviation. The timing at which the light emission signal for emitting the light is supplied to the laser light source is adjusted.

  Thereby, it is possible to accurately irradiate the processing set position with the laser beam having the processing intensity. Therefore, the processing position accuracy of laser processing can be improved. As a result, for example, it is possible to accurately form and form minute processing marks (pits or the like) on the processing object in a square shape or a hexagonal close-packed shape.

  Another feature of the present invention is that the emission signal supply means includes a high level signal for emitting laser light having a processing intensity to the laser light source and a low level signal for emitting laser light having a non-processing intensity. Output a pulse train signal that alternately switches at a constant cycle, and the movement control means is configured such that, when the light emission signal supply means outputs the pulse train signal, the irradiation position of the laser beam is at a constant speed along the movement route. The laser beam irradiation control unit supplies the pulse train signal to the laser light source to the light emission signal supply unit when the processing start setting position is detected. The light emission signal supply timing adjustment means outputs the command when the timing deviation is detected by the timing deviation detection means. For a time corresponding to the grayed misalignment is to reduce the time width of one low-level signal at the pulse train signal.

  In the present invention, when a machining start set position is detected, a supply command for supplying a pulse train signal to the laser light source is output to the light emission signal supply means. In response to this supply command, the light emission signal supply means alternately generates a high level signal for emitting laser light having a processing intensity to the laser light source and a low level signal for emitting laser light having a non-processing intensity at regular intervals. The pulse train signal to be switched is output. As a result, laser light having processing intensity and laser light having non-processing intensity are alternately emitted from the laser light source. When this laser beam is emitted, the irradiation position of the laser beam moves along the moving route at a constant speed (a constant speed). Therefore, it is possible to form processing marks on the processing object at a predetermined interval. In this case, at the processing start setting position, the irradiation of the processing intensity laser light is delayed, so that a processing mark is formed at a position deviated from the processing start setting position. Since the time width (output period) of one low-level signal in the pulse train signal is shortened by the time corresponding to the deviation, a machining trace is formed at the machining setting position thereafter. Therefore, the processing position accuracy of laser processing can be improved.

  Another feature of the present invention is that the movement control means reciprocates the irradiation position of the laser beam between the first stop position and the second stop position in the X direction, and the first stop position and the second stop position. The laser light irradiation control means is configured to move the laser light irradiation position within a machining setting range set between the first stop position and the second stop position. Each time it is detected that the processing start position has been reached, a supply command for supplying the pulse train signal to the laser light source is output to the light emission signal supply means, and the timing deviation detection means Each time it is detected that the irradiation position of the laser beam has reached the processing start position, from the timing at which it is detected that the irradiation position of the laser beam has reached the processing start position, The light emission signal supply timing adjusting means detects the timing deviation up to the timing at which the laser beam having the working intensity is emitted, and the light emission signal supply timing adjusting means responds to the timing deviation each time the timing deviation is detected by the timing deviation detecting means. The time width of one low level signal in the pulse train signal is shortened by time.

  In the present invention, the irradiation position of the laser beam on the workpiece is reciprocated in the X direction between the first stop position and the second stop position, and reaches the first stop position and the second stop position. Each time it moves in the Y direction by the feed pitch. The machining setting range (machining region) in the X direction is provided between the first stop position and the second stop position. The laser beam irradiation control unit supplies the pulse train signal to the laser light source every time it is detected that the laser beam irradiation position has reached the processing start position that is the start of the processing setting range. Outputs a command. At this time, the timing deviation detection means detects the timing deviation from the timing at which the laser light irradiation position is detected to have reached the processing start position to the timing at which the laser light having the processing intensity is emitted from the laser light source, Each time the timing deviation is detected by the timing deviation detection means, the light emission signal supply timing adjustment means shortens the time width of one low-level signal in the pulse train signal by the time corresponding to the timing deviation. Therefore, each time the laser beam irradiation position moves in the X direction and enters the machining setting range, timing deviation is detected and the time width of the low-level signal is adjusted based on the detection. As a result, the processing position accuracy of laser processing can be further improved. In particular, when the present invention is applied in the manufacturing process of LED and liquid crystal substrates, it becomes easy to form fine processing traces (pits, etc.) on the substrate in a square shape or a hexagonal fine shape with high precision, and high quality. LED and liquid crystal substrates can be manufactured.

  In addition, another feature of the present invention is that each time it is detected that the irradiation position of the laser light has reached a specific processing setting position set in the middle of the processing setting range, the irradiation position of the laser light is An intermediate timing deviation detecting means for detecting a timing deviation from a timing at which the specific processing set position is detected to a timing at which a laser beam of machining intensity is emitted from the laser light source, and an intermediate timing deviation detecting means By changing the time width of one low level signal in the pulse train signal based on the detected timing deviation, the timing at which the light emission signal for emitting the laser beam having the processing intensity is supplied to the laser light source is set. There is provided a light emission signal supply timing adjusting means during the adjustment.

  In the present invention, the midway timing deviation detecting means detects that the laser beam irradiation position has reached a specific machining setting position (machining setting position also used for timing deviation detection) set in the middle of the machining setting range. Every time, a timing shift is detected from the timing at which the laser light irradiation position is detected to reach the specific processing set position to the timing at which the laser light having the processing intensity is emitted from the laser light source. Then, the light emission signal for emitting the processing intensity laser light is generated by changing the time width of one low-level signal in the pulse train signal based on the timing deviation, so that the light emission signal for emitting the processing-intensity laser light Adjust the timing supplied to the light source. That is, in the present invention, a timing shift is detected not only at the start of processing but also during laser processing, and the time width of one low-level signal in the pulse train signal is changed based on the timing shift. As a result, for example, even when the irradiation position of the laser beam cannot move accurately within the processing setting range at a constant speed, the emission signal for emitting the laser beam having the processing intensity during the laser processing is obtained. Since the supply timing is adjusted, high processing position accuracy can be maintained.

  Another feature of the present invention is that the light emission signal supply means outputs a high level signal for outputting a laser beam having a processing intensity to the laser light source, and immediately before outputting the high level signal. Outputs a pulse signal having a low level period for outputting a low level signal for emitting non-processing intensity laser light, and outputs a non-processing intensity laser light when the pulse signal is not output. A level direct current signal is output, and the laser light irradiation control means detects the pulse signal to the light emission signal supply means each time a light emission command position set at a position before the machining setting position is detected. The light emission signal supply timing adjusting means determines the distance between the processing setting position and the light emission command position by the laser light irradiation position. From the time required for moving is a time obtained by subtracting the time of the detected timing deviation by said timing shift detection means to be configured as a low-level period of the pulse signal.

  In the present invention, when laser processing is performed, the light emission signal supply means outputs a pulse signal to the laser light source, and when laser processing is not performed, a low-level DC signal is output. The pulse signal includes a high-level period for outputting a high-level signal for emitting laser light with processing intensity to the laser light source, and a low-level signal for emitting laser light with non-processing intensity immediately before outputting the high-level signal. A low level period for output is provided. Therefore, when this light emission signal is supplied to the laser light source, the laser light source first emits laser light having non-processing intensity by a low level signal, and then emits laser light having processing intensity by a high level signal. . Therefore, by adjusting the low level period (time width), it is possible to adjust the time until the high level signal for emitting the laser beam having the processing intensity is supplied to the laser light source.

  The laser light irradiation control means outputs a pulse signal supply command to the light emission signal supply means each time a light emission command position set at a position before the processing set position is detected. That is, the pulse signal supply command is output earlier than the timing at which the machining setting position is detected. This signal quick start time is the time required for the laser beam irradiation position to move the distance between the machining setting position and the light emission command position. Accordingly, if the time obtained by subtracting the time of timing deviation from the signal quick start time is set in the low level period of the pulse signal, the processing set position can be irradiated with the laser beam having the processing intensity. Therefore, the light emission signal supply timing adjustment means calculates the time of the timing deviation detected by the timing deviation detection means from the time required for the laser light irradiation position to move the distance between the processing setting position and the light emission command position. The subtracted time is set as the low level period. Thereby, the irradiation position of the processing laser beam can be adjusted for each processing set position. For this reason, even if the irradiation position of the laser beam cannot move accurately within the processing setting range at a constant speed (constant speed), high processing position accuracy can be maintained. For example, if the present invention is applied in the LED or liquid crystal substrate manufacturing process, it becomes easy to accurately form and form minute processing traces (pits, etc.) on the substrate in a square shape or a hexagonal shape. LED and liquid crystal substrates can be manufactured.

  Furthermore, in carrying out the present invention, the invention is not limited to the invention of the laser processing apparatus, but can also be implemented as an invention of a laser processing method.

1 is a system configuration diagram of a laser processing apparatus according to an embodiment. It is a wave form diagram showing a light emission signal (pulse train signal). It is an XY coordinate diagram showing a processing area and a processing movement route. It is a flowchart showing a part of laser processing control routine. It is a flowchart showing a part of laser processing control routine. It is a flowchart showing a part of laser processing control routine. It is a flowchart showing a part of laser processing control routine. It is a flowchart showing a part of timing adjustment routine. It is a flowchart showing a part of timing adjustment routine. It is a signal waveform diagram when laser processing is started in the X direction. It is a flowchart showing a part of timing adjustment routine which concerns on a modification. It is a flowchart showing a part of timing adjustment routine which concerns on a modification. It is a signal waveform diagram when laser processing is started in the X direction according to a modification. It is a wave form diagram showing the luminescence signal (pulse signal) concerning a 2nd embodiment. It is a flowchart showing a part of laser processing control routine which concerns on 2nd Embodiment. It is a flowchart showing a part of laser processing control routine which concerns on 2nd Embodiment. It is a flowchart showing a part of timing adjustment routine which concerns on 2nd Embodiment. It is a flowchart showing a part of timing adjustment routine which concerns on 2nd Embodiment. It is a flowchart showing a part of timing adjustment routine which concerns on 2nd Embodiment. It is a signal waveform diagram when laser processing is started in the X direction according to the second embodiment. It is a signal waveform diagram when laser processing is started in the X direction according to the conventional example. It is explanatory drawing showing the shift | offset | difference of the processing trace which concerns on a prior art example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic system configuration diagram of a laser processing apparatus 1 according to the embodiment. The laser processing apparatus 1 sets (fixes and supports) a flat plate-shaped workpiece OB and moves the position of the workpiece OB in the X and Y directions, and performs processing by irradiating laser light. And a processing head 30 for laser processing the surface of the object OB. The processing object OB is used as a substrate for an LED or the like by forming innumerable nano-sized ultra-fine pits in a square arrangement on the surface by the laser light emitted from the processing head 30. The processing head 30 is fixed by a head support frame (not shown) fixed to the apparatus main body.

  The stage driving device 20 includes a stage 21 on which the workpiece OB is placed and fixed, an X-direction feed motor 22 that moves the stage 21 in the X direction (left-right direction in FIG. 1), and the stage 21 in the Y direction (FIG. 1). , A Y-direction feed motor 23 that is moved in the depth direction) is provided. The X direction and the Y direction are one direction parallel to the mounting surface of the stage 21 and are orthogonal to each other. The stage driving device 20 includes a screw feed mechanism 24 connected to the output shaft of the X-direction feed motor 22 and a screw feed mechanism (not shown) connected to the output shaft of the Y-direction feed motor 23 to each feed motor. The XY stage moves the stage 21 in the X direction and the Y direction by rotating 22 and 23.

  In the X-direction feed motor 22, an encoder 22a that detects the rotation of the motor 22 and outputs a rotation signal representing the rotation is incorporated. This rotation signal is a pulse train signal that alternately switches between a high level and a low level every time the X-direction feed motor 22 rotates by a predetermined minute angle, and has a phase of π / 2 to identify the rotation direction. It consists of the shifted A phase signal and B phase signal. The rotation signal is output to the X direction feed motor control circuit 42 and the X direction position detection circuit 44.

  The X direction position detection circuit 44 counts up or down the number of pulses of the rotation signal from the encoder 22a according to the rotation direction of the X direction feed motor 22, detects the X direction position of the stage 21 from the count value, A signal representing the directional position (hereinafter simply referred to as the X position) is output to the controller 90. Since the X position represents the relative position in the X direction of the stage 21 with respect to the processing head 30, it is treated as the X coordinate value of the irradiation position of the laser beam irradiated from the processing head 30 onto the processing object OB. Note that the irradiation position of the laser beam is a position where the processing head 30 can collect and irradiate the laser beam, and does not ask whether the laser beam is actually irradiated on the processing object OB.

  The initial setting of the count value in the X-direction position detection circuit 44 is performed according to an instruction from the controller 90 when the power is turned on. That is, when the power is turned on, the controller 90 instructs the X-direction feed motor control circuit 42 to move the stage 21 to the X-direction limit position and the X-direction position detection circuit 44 to perform initial setting. In response to this instruction, the X-direction feed motor control circuit 42 rotates the X-direction feed motor 22 to move the stage 21 to the X-direction limit position. This X direction limit position is a drive limit position in the X direction of the stage 21 driven by the X direction feed motor 22. The X-direction position detection circuit 44 continues to input the rotation signal from the encoder 22a while the stage 21 is moving. When the stage 21 reaches the X-direction limit position and the rotation of the X-direction feed motor 22 stops, the X-direction position detection circuit 44 detects the stop of the rotation signal input from the encoder 22a and sets the count value to “0”. Reset to. At this time, the X-direction position detection circuit 44 outputs a signal for stopping the output to the X-direction feed motor control circuit 42, whereby the X-direction feed motor control circuit 42 outputs a drive signal to the X-direction feed motor 22. Stop output. Thereafter, when the X-direction feed motor 22 is driven, the X-direction position detection circuit 44 counts up or counts down the number of pulses of the rotation signal in accordance with the rotation direction of the X-direction feed motor 22, and the count value The X position of the stage 21 is calculated based on the above and a digital signal representing the X position is continuously output to the X direction feed motor control circuit 42 and the controller 90. Each time the X position moves by a predetermined distance α, the X direction position detection circuit 44 outputs an X position detection signal representing the X position at that time. Hereinafter, the predetermined distance α is referred to as a detection unit distance α.

  Similarly, an encoder 23 a that detects the rotation of the motor 23 and outputs a rotation signal representing the rotation is also incorporated in the Y-direction feed motor 23. Similar to the encoder 22a in the X-direction feed motor 22, this rotation signal is a pulse train signal that alternately switches between a high level and a low level each time the Y-direction feed motor 23 rotates by a predetermined minute angle. It is composed of an A-phase signal and a B-phase signal that are out of phase by π / 2. This rotation signal is output to the Y-direction feed motor control circuit 43 and the Y-direction position detection circuit 45.

  The Y-direction position detection circuit 45 counts up or down the number of pulses of the rotation signal from the encoder 23a according to the rotation direction of the Y-direction feed motor 23, detects the Y-direction position of the stage 21 from the count value, and Y A digital signal representing a directional position (hereinafter simply referred to as a Y position) is output to the controller 90. Since the Y position represents the relative position of the stage 21 in the Y direction with respect to the processing head 30, it is treated as the Y coordinate value of the irradiation position of the laser beam irradiated from the processing head 30 onto the processing object OB.

  The initial setting of the count value in the Y-direction position detection circuit 45 is performed according to an instruction from the controller 90 when the power is turned on, similarly to the X-direction position detection circuit 44. That is, when an initial setting is instructed from the controller 90, the Y-direction feed motor control circuit 43 rotates the Y-direction feed motor 23 to move the stage 21 to the Y-direction limit position. The Y-direction position detection circuit 45 resets the count value to “0” and detects the Y-direction feed motor when it detects that the stage 21 reaches the Y-direction limit position and the input of the rotation signal from the encoder 23a has stopped. An output stop signal is output to the control circuit 43. Thereafter, the Y-direction position detection circuit 45 counts up or down the number of pulses of the rotation signal in accordance with the rotation direction of the Y-direction feed motor 23, and calculates the Y position of the stage 21 based on the count value. Is continuously output to the Y-direction feed motor control circuit 43 and the controller 90.

  The X-direction feed motor control circuit 42 drives and controls the X-direction feed motor 22 according to instructions from the controller 90 to move the stage 21 to a designated X position or at a designated speed. Specifically, the X direction feed motor control circuit 42 uses the X position detected by the X direction position detection circuit 44 when the movement to the X position designated by the controller 90 is instructed. The rotation of the X direction feed motor 22 is rotated until the detected X position becomes equal to the X position designated by the controller 90. Further, when a movement start command is instructed by the controller 90, the X direction feed motor control circuit 42 calculates the moving speed in the X direction of the stage 21 from the rotation signal output from the encoder 22a, and the calculated moving speed is The rotation of the X direction feed motor 22 is controlled so as to be equal to the moving speed designated by the controller 90.

  Similarly to the X-direction feed motor control circuit 42, the Y-direction feed motor control circuit 43 determines that the Y position detected by the Y-direction position detection circuit 45 is designated Y when the controller 90 is instructed to move to the specified Y position. The Y-direction feed motor 23 is rotated until it becomes equal to the position, and when the movement start command is instructed by the controller 90, the movement speed in the Y direction of the stage 21 is calculated from the rotation signal output from the encoder 23a. The rotation of the Y-direction feed motor 23 is controlled so that the moving speed becomes equal to the moving speed specified by the controller 90.

  Next, the processing head 30 will be described. The processing head 30 includes a laser light source 31 and is configured to irradiate the processing object OB with the laser light emitted from the laser light source 31 and receive the reflected light. The processing head 30 includes a laser light source 31, a collimating lens 32, a polarizing beam splitter 33, a ¼ wavelength plate 34, an objective lens 35, a condensing lens 36, a cylindrical lens 37, a photodetector 38, and a focus actuator 39. Laser light emitted from the laser light source 31 is converted into parallel light by the collimator lens 32 and enters the polarization beam splitter 33. Most of the laser light (for example, 95%) is transmitted through the polarization beam splitter 33 as it is, and a part of the laser light is reflected by the polarization beam splitter 33.

  The laser beam that has passed through the polarization beam splitter 33 passes through the quarter-wave plate 34 and becomes circularly polarized light, and is condensed on the surface of the workpiece OB by the objective lens 35. The laser beam condensed on the surface of the workpiece OB is reflected on the surface of the workpiece OB. The reflected light reflected by the surface of the workpiece OB is converted into parallel light by the objective lens 35, and becomes linearly polarized light whose polarization direction is 90 ° different from the polarization direction at the time of passing through the quarter-wave plate 34, The light is incident on the polarization beam splitter 33, and most (for example, 95%) of the light is reflected by the polarization beam splitter 33 and enters the condenser lens 36. The condensing lens 36 condenses the light reflected by the polarization beam splitter 33 on the photodetector 38 via the cylindrical lens 37. The light reception signal output from the photodetector 38 is used for focus servo control described later.

  Further, the machining head 30 reflects a part of the laser light emitted from the laser light source 31 (for example, 5%) by the polarization beam splitter 33 and collects the reflected light on the light receiving surface of the photodetector 41 by the condenser lens 40. It has a light-emitting configuration. The photodetector 41 outputs a light reception signal corresponding to the intensity of the laser light emitted from the laser light source 31. The received light signal is amplified by the signal amplifying circuit 71 and then fed back to the laser driving circuit 70 to be used for adjusting the intensity of the laser beam. Used to detect Dev).

  Next, laser beam focus servo will be described. The photo detector 38 that receives the reflected light from the surface of the workpiece OB of the laser beam is composed of four divided light receiving elements composed of four identical square light receiving elements divided by dividing lines, and is arranged in a clockwise direction. A detection signal having a magnitude proportional to the intensity of light incident on the light receiving regions A, B, C, and D is output as a light receiving signal (a, b, c, d). The photodetector 38 is fixed so that the reflected light is collected at the center where the four light receiving elements are arranged.

  The received light signals (a, b, c, d) output from the photodetector 38 are input to the HF signal amplifier circuit 61. The HF signal amplification circuit 61 amplifies the received light signals (a, b, c, d) and outputs the amplified signals to the focus error signal generation circuit 62. The focus error signal generation circuit 62 generates a focus error signal by calculation using the amplified light reception signals (a ′, b ′, c ′, d ′). In the present embodiment, since focus servo control by the astigmatism method is used, the calculation of (a ′ + c ′) − (b ′ + d ′) is performed. The focus error signal generation circuit 62 outputs a focus error signal as a calculation result to the focus servo circuit 63 via the conduction circuit 65. The focus error signal (a ′ + c ′) − (b ′ + d ′) represents the amount of deviation of the focal position of the laser beam from the surface of the workpiece OB.

  While the low level signal is input from the mask signal generation circuit 66, the conduction circuit 65 outputs the focus error signal input from the focus error signal generation circuit 62 to the focus servo circuit 63 as it is, and from the mask signal generation circuit 66. While the high level signal is input, the focus error signal input from the focus error signal generation circuit 62 is blocked. Therefore, while a high level signal is being input from the mask signal generation circuit 66, a focus error signal with (a ′ + c ′) − (b ′ + d ′) = 0 is input to the focus servo circuit 63. It will be.

  The focus servo circuit 63 is controlled by the controller 90, generates a focus servo signal based on the focus error signal, and outputs the focus servo signal to the drive circuit 64. The drive circuit 64 controls the focus actuator 39 according to the focus servo signal to displace the objective lens 35 in the optical axis direction of the laser light. In this case, the focus servo signal is generated so that the value of the focus error signal (a ′ + c ′) − (b ′ + d ′) is always zero, thereby condensing the laser beam on the surface of the workpiece OB. You can continue.

  Therefore, when the focus error signal output from the focus error signal generation circuit 62 is interrupted by the conduction circuit 65, the focus servo control is held. That is, the position of the objective lens 35 is maintained so as not to change. The mask signal generation circuit 66 switches the level (high level and low level) of the signal output to the conduction circuit 65 according to a command from the controller 90. For this reason, the controller 90 can control the hold and release of the focus servo control by a command to the mask signal generation circuit 66.

  The laser light source 31 is driven by a laser driving circuit 70. The laser drive circuit 70 starts operating in response to a command from the controller 90 and outputs a laser drive signal corresponding to the light emission signal supplied from the pulse signal supply device 50 to the laser light source 31. The pulse signal supply device 50 can switch the level of the light emission signal output to the laser driving circuit 70 in two stages, a high level and a low level. The laser drive circuit 70 continues to output the processing laser drive signal to the laser light source 31 while the high level light emission signal is being input, and to the laser light source 31 while the low level light emission signal is being input. In contrast, the non-machining laser drive signal is continuously output. The laser light source 31 emits a laser beam with a processing intensity while inputting a processing laser drive signal, and emits a laser beam with a non-processing intensity while inputting a non-processing laser drive signal. . The processing intensity means that the surface of the processing object OB is processed by the irradiation of the laser light emitted from the laser light source 31 (including one that forms a reaction trace in the photoresist) and enables focus servo control. It means strength. The non-processing intensity means an intensity at which the surface of the processing object OB is not processed by the irradiation of the laser light emitted from the laser light source 31 and focus servo control is possible.

  In this embodiment, the light emission signal output from the pulse signal supply device 50 is converted into a laser drive signal by the laser drive circuit 70 and output to the laser light source 31. The function of the circuit 70 may be provided. Accordingly, the laser light irradiation signal supplied from the pulse signal supply device 50 to the laser light source 31 via the laser driving circuit 70 corresponds to the light emission signal of the present invention.

  When the pulse signal supply device 50 receives a non-processing intensity laser irradiation start command in response to a command from the controller 90, the pulse signal supply device 50 starts outputting a low-level DC signal, and receives a processing intensity laser irradiation start command from the controller 90. The pulse train signal having a waveform stored in the memory 50a provided therein is output. As shown in FIG. 2, the pulse train signal includes a high level signal HS that causes the laser light source 31 to emit laser light having a processing intensity, and a low level that causes the laser light source 31 to emit laser light having a non-processing intensity. The signal LS is a signal that is alternately switched at a constant cycle.

  The pulse signal supply device 50 uses the signal intensity of the high level signal HS, the time width (pulse width) of the high level signal HS, the signal intensity of the low level signal LS, and the time of the low level signal LS as information of the pulse train signal. Digital data representing the width is input in advance from the controller 90 and stored in the internal memory 50a. Based on this data, digital data representing the waveform of a pulse signal for one period (a waveform combining a high level signal and a low level signal) is created and stored in the memory 50a. When an output command of the processing intensity laser light is input from the controller 90, an analog pulse train signal in which pulse signals for one cycle are continuous is generated and output to the laser driving circuit 70. This pulse train signal is generated so as to start from a high level signal. In this case, the time width of the high level signal HS is set to Ht, and the time width of the low level signal LS is set to Lt (see FIG. 2).

  Further, the pulse signal supply device 50 outputs a DC signal having the same intensity as the signal intensity of the low level signal LS to the laser drive circuit 70 when an output command of non-processing intensity laser light is input from the controller 90. . The pulse signal supply device 50 stops signal output after inputting a laser irradiation stop command from the controller 90. For this reason, the signal input to the laser drive circuit 70 becomes zero level, and the laser drive circuit 70 stops outputting the laser drive signal. Accordingly, the laser light is not emitted from the laser light source 31. The laser drive circuit 70 receives a signal representing the intensity of the laser light emitted from the laser light source 31 from the signal amplification circuit 71, and the intensity of the processing laser light and the intensity of the non-processing laser light are respectively set. If they differ from the target intensity, the intensity of the laser drive signal is adjusted so that they match the target intensity.

  Next, a configuration for detecting the delay time will be described. The delay time is when the controller 90 outputs to the pulse signal supply device 50 a command for causing the laser beam with the processing intensity to be emitted at the timing when the X-direction position detection circuit 44 detects the X-direction processing start setting position. From the timing at which the processing start setting position is detected until the laser light having the processing intensity is actually emitted from the laser light source 31 (the intensity of the laser light emitted from the laser light source 31 is switched from the non-processing intensity to the processing intensity). Time). The laser processing apparatus 1 includes a signal input detection circuit 80, a delay signal generation circuit 81, and an A / D converter 82 as a configuration for detecting the delay time. When the operation start command is input from the controller 90 and the detection signal of the machining start set position is input from the X-direction position detection circuit 44, the signal input detection circuit 80 is a high-level signal input detection indicating that the signal has been input. A signal (one pulse signal) is output to the delay signal generation circuit 81. Once the signal input detection circuit 80 outputs the signal input detection signal, it does not output the signal input detection signal unless the operation start command is input again from the controller 90.

  When the signal output from the signal input detection circuit 80 becomes high level, the delay signal generation circuit 81 sets its own output to high level, and the signal output from the signal amplification circuit 71 indicating the intensity of the laser light changes from low level to high level. When the level is switched to the level (the level when the processing intensity laser beam is irradiated), the circuit is configured to switch its output from the high level to the low level. Therefore, the pulse width of the output signal of the delay signal generation circuit 81 (high level period) is from the timing when the X-direction position detection circuit 44 detects the processing start setting position to the timing when the intensity of the laser beam is switched to the processing intensity. It represents the delay time.

  The A / D converter 82 receives the output signal of the delay signal generation circuit 81, converts the instantaneous value of the input signal into digital data, and outputs the digital data to the controller 90. The controller 90 detects the delay time by processing the signal output from the A / D converter 82.

  The controller 90 is an electronic control unit having a microcomputer including a CPU, a ROM, and a RAM as a main part, and includes a memory 90a that stores various processing data. Further, the controller 90 includes an input device 91 for an operator to instruct various parameters and processing, and a display device 92 for visually notifying the operator of various setting conditions and operating conditions. It is connected.

  Next, laser processing performed by the laser processing apparatus will be described. First, a laser processing region and a moving route of laser light in the processing object OB will be described. FIG. 3 shows XY coordinates for setting a processing area of the processing object OB. In the figure, a gray area is a processing area (processing setting range). The processing area is a rectangular area surrounded by a range from the D position to the D ′ position in the X coordinate and a range from the S position to the E position in the Y coordinate. At the time of laser processing, the laser light irradiation position is linearly moved in the X direction from the start point St outside the processing area to the A ′ position by the position control of the stage driving device 20, and then the feed pitch in the Y direction is set. Moving. This time, the linear movement is made in the opposite direction and the movement returns to the A position to make one reciprocal movement. By repeating this reciprocating movement until the Y position becomes the E position, the laser beam irradiation position can be moved to the entire processing region. In this case, the intensity of the laser beam is set to a non-machining intensity when the laser beam irradiation position is out of the processing region, and the pulse signal supply device 50 outputs when the laser beam irradiation position moves within the processing region. The strength for machining and the strength for non-machining are switched in synchronization with the pulse train signal to be performed. Hereinafter, the laser beam output from the laser light source 31 in accordance with the pulse train signal is referred to as a processing pulse laser beam.

  Here, a specific position necessary for machining control in the XY coordinates shown in FIG. 3 will be described. The position D and the position D ′ described above are positions where the irradiation of the processing pulsed laser beam is started or stopped. Therefore, hereinafter, the positions D and D 'are referred to as machining start positions D and D'. Position A and position A ′ are positions where movement of the laser light irradiation position in the X direction stops. Therefore, hereinafter, the positions A and A ′ are referred to as stop positions A and A ′. Further, positions B and C, and positions B ′ and C ′ are set between the positions A and D in the X coordinate and between the positions A ′ and D ′. The positions B and B ′ are positions at which the moving speed becomes constant speed (constant speed) after the laser beam irradiation position starts moving in the X direction from the stop position A or A ′. Therefore, hereinafter, the positions B and B 'are referred to as constant speed moving positions B and B'. Position C and position C ′ are positions for switching focus servo hold / hold release. Therefore, hereinafter, the positions C and C ′ are referred to as hold switching positions C and C ′. In the drawing, a position Ft is a position where focus servo is started. These positions A to D and A 'to D' represent X coordinate values. On the other hand, with respect to the position in the Y coordinate, a position S and a position E are set. Since the position S is a position where laser processing is started, it is hereinafter referred to as a start position S. Since the position E is a position where the laser processing is ended, hereinafter, it is referred to as an end position E. These positions S and E represent Y coordinate values.

  Note that the positions A to D and A 'to D' are set to positions where the X direction position detection circuit 44 outputs an X position detection signal. The positions S and E are set to positions where the Y-direction position detection circuit 45 outputs a Y position detection signal. Further, the distance between the positions DD ′ is equal to the time of the high level signal HS when the time during which the laser beam irradiation position moves at a constant speed between the positions DD ′ is an integral multiple of the period (Ht + Lt) of the pulse train signal. It is set to be a time ((Ht + Lt) · n + Ht) obtained by adding one width Ht. In other words, when the laser beam irradiation position goes out of the machining area from the machining start position D, and when the laser beam irradiation position goes out of the machining area from the machining start position D ′, the time period during which the pulse train signal becomes high level The timing is set to end when the width Ht elapses. In addition, a single feed amount in the Y direction is set to be equal to the machining pitch in the X direction.

  Next, laser processing control processing will be described. 4A to 4D show a laser processing control routine executed by the controller 90. FIG. The laser processing control routine is stored as a control program in the ROM of the controller 90, and starts when the operator inputs a laser processing start command from the input device 91 after setting the processing object OB on the stage 21. The laser processing control routine is performed in parallel with a timing adjustment routine (FIGS. 5A to 5B) described later.

  When the laser processing control routine is started in step S100, the controller 90 first sets the value of the variable n to “0” in step S102. Subsequently, in step S104, a command to move to the hold switching position C is output to the X-direction feed motor control circuit 42. Based on this command, the X direction feed motor control circuit 42 rotates the X direction feed motor 22 until the X position detected by the X direction position detection circuit 44 becomes equal to the hold switching position C. Subsequently, the controller 90 outputs a movement command to the start position S to the Y-direction feed motor control circuit 43 in step S106. Based on this command, the Y-direction feed motor control circuit 43 rotates the Y-direction feed motor 23 until the Y position detected by the Y-direction position detection circuit 45 becomes equal to the start position S.

  Subsequently, the controller 90 waits until the X position becomes equal to the hold switching position C while inputting the X position from the X direction position detection circuit 44 in steps S108 and S110. Then, when it is detected that the X position becomes equal to the hold switching position C (S110: Yes), in the subsequent steps S112 and S114, the Y position is input from the Y direction position detection circuit 45 and the Y position is set to the start position S. Wait until it is equal to. When it is detected that the Y position is equal to the start position S (S114: Yes), in step S116, a drive start command is output to the laser drive circuit 70, and a low-level direct current is supplied to the pulse signal supply device 50. Outputs a signal output start command. As a result, the pulse signal supply device 50 starts outputting the DC signal set to the low level. The laser drive circuit 70 receives the DC signal output from the pulse signal supply device 50 and outputs a non-machining laser drive signal to the laser light source 31. The laser light source 31 is driven by the non-machining laser drive signal output from the laser driving circuit 70 and emits laser light having non-machining intensity. As a result, the surface of the processing object OB is irradiated with laser light having non-processing intensity, and the reflected light is detected by the photodetector 38. In this case, the processing object OB is not processed by irradiation with laser light having non-processing intensity.

  Subsequently, in step S118, the controller 90 outputs a focus servo start command to the focus servo circuit 63, a circuit that drives the focus actuator 39 (not shown), and the S-shaped detection circuit. Thereby, the focus position of the laser beam moves in the optical axis direction of the laser beam, and the focus servo is started at the timing when the focus position of the laser beam coincides with the surface of the workpiece OB.

  Thus, when the focal position of the laser beam coincides with the surface of the workpiece OB, the controller 90 outputs a hold command signal for focus servo control to the mask signal generation circuit 66 in step S120. As a result, the mask signal generation circuit 66 outputs a high level signal to the conduction circuit 65, and the focus servo control is held. Accordingly, the position of the objective lens 35 is maintained so as not to change.

  Subsequently, the controller 90 outputs a movement command to the stop position A to the X-direction feed motor control circuit 42 in step S122. Thereby, the X-direction feed motor control circuit 42 rotates the X-direction feed motor 22 until the X position becomes equal to the stop position A. Subsequently, the controller 90 waits until the X position becomes equal to the stop position A while inputting the X position from the X direction position detection circuit 44 in steps S124 and S126. When it is detected that the X position becomes equal to the stop position A (S126: Yes), a movement start command in the X positive direction is output to the X direction feed motor control circuit 42 in step S128. As a result, the X-direction feed motor control circuit 42 drives the X-direction feed motor 22 to rotate forward so as to move the stage 21 so that the laser light irradiation position moves in the X-positive direction. The stage 21 moves at an acceleration at the start of movement, but moves at a constant speed when the roller passes the constant speed movement position B.

  Subsequently, in steps S130 and S132, the controller 90 waits until the X position becomes equal to or higher than the hold switching position C while inputting the X position from the X direction position detection circuit 44, and the X position becomes equal to or higher than the hold switching position C. In step S134, a focus servo control hold release command signal is output to the mask signal generation circuit 66. As a result, the mask signal generation circuit 66 switches the signal output to the conduction circuit 65 from the high level to the low level. Thus, the focus error signal output from the focus error signal generation circuit 62 is input to the focus servo circuit 63, and focus servo control is started. That is, the objective lens 35 is driven and controlled in the optical axis direction of the laser light so that the focal position of the laser light coincides with the surface of the workpiece OB. In the present specification, as in step S132, the comparison of the size of the X position (Y position) means the comparison of the size of the X coordinate value (Y coordinate value).

  Subsequently, in Steps S136 and S138, the controller 90 waits until the X position becomes equal to or greater than the machining start position D while inputting the X position from the X direction position detection circuit 44, and the X position becomes equal to or greater than the machining start position D. Then, in step S140, an irradiation start command of the processing pulse laser beam is output to the pulse signal supply device 50. As a result, the pulse signal supply device 50 starts outputting a pulse train signal in which the high level signal and the low level signal are alternately repeated. The laser drive circuit 70 receives the pulse train signal output from the pulse signal supply device 50 and alternately outputs a processing laser drive signal and a non-processing laser drive signal to the laser light source 31. The laser light source 31 is driven by the laser drive signal output from the laser drive circuit 70 and emits a processing pulse laser beam.

  In steps S142 and S144, the controller 90 waits until the X position becomes equal to or greater than the machining start position D ′ while inputting the X position from the X direction position detection circuit 44. During this standby, the surface of the workpiece OB is intermittently irradiated with laser light having a processing intensity, and pits are intermittently formed on the surface of the workpiece OB. When the X position becomes equal to or greater than the machining start position D ′, the controller 90 outputs a non-machining laser beam irradiation start command to the pulse signal supply device 50 in step S146. As a result, the pulse signal supply device 50 starts outputting a DC signal set at a low level instead of the pulse train signal. Therefore, at this point, laser processing is temporarily interrupted. Thus, pits (machining traces) are linearly arranged at predetermined intervals between the machining start position D and the machining start position D ′.

  Subsequently, in Steps S148 and S150, the controller 90 waits until the X position becomes equal to or higher than the hold switching position C ′ while inputting the X position from the X direction position detection circuit 44, and the X position becomes the hold switching position C ′. In step S152, the focus servo control hold command signal is output to the mask signal generation circuit 66. Thereby, the focus servo control is held. Subsequently, in Steps S154 and S156, the controller 90 waits until the X position becomes equal to or higher than the constant velocity movement position B ′ while inputting the X position from the X direction position detection circuit 44, and the X position is equal to the constant velocity movement position. When B ′ or more, in step S158, a movement stop command in the X positive direction of the stage 21 is output to the X direction feed motor control circuit 42. Based on this command, the X-direction feed motor control circuit 42 stops driving the X-direction feed motor 22. Although it is a very short time to stop the X-direction feed motor 22, it is stopped at the stop position A 'because a deceleration period is necessary.

  Subsequently, in step S160, the controller 90 increments the value of the variable n by “1”. In step S162, it is determined whether or not the Y position (S + n · p) represented by the sum of the value obtained by multiplying the feed pitch p in the Y direction by the variable n and the start position S exceeds the end position E. When the determination in step S162 is first performed after the start of the laser processing control routine, the determination is “No”, and the process proceeds to step S167. In step S167, the controller 90 outputs a movement command to the Y position (S + n · p) to the Y-direction feed motor control circuit 43. Based on this command, the Y-direction feed motor control circuit 43 performs the Y-direction feed motor until the Y position detected by the Y-direction position detection circuit 45 becomes equal to the Y position (S + n · p) designated by the movement command. 23 is rotated.

  In steps S168 and S169, the controller 90 waits until the Y position becomes equal to the Y position (S + n · p) while inputting the Y position from the Y-direction position detection circuit 45, and the Y position becomes the Y position (S + n · p). ), A movement start command in the X negative direction is output to the X direction feed motor control circuit 42 in step S170. As a result, the X-direction feed motor control circuit 42 drives the X-direction feed motor 22 in a reverse rotation to move the stage 21 so that the laser beam irradiation position moves in the X negative direction. The stage 21 moves at an acceleration at the start of movement, but moves at a constant speed when the roller passes the constant speed movement position B ′.

  Subsequently, in Steps S172 and S174, the controller 90 waits until the X position becomes equal to or lower than the hold switching position C ′ while inputting the X position from the X direction position detection circuit 44, and the X position becomes the hold switching position C ′. When it is below, in step S176, a focus servo control hold release command signal is output to the mask signal generation circuit 66. Thereby, focus servo control is started. Subsequently, in Steps S178 and S180, the controller 90 waits until the X position becomes equal to or less than the machining start position D ′ while inputting the X position from the X direction position detection circuit 44, and the X position becomes the machining start position D ′. In step S182, an irradiation start command for the processing pulse laser beam is output to the pulse signal supply device 50 in step S182. As a result, the pulse signal supply device 50 starts outputting the pulse train signal, and the laser light source 31 starts emitting the processing pulse laser beam.

  Subsequently, in steps S184 and S186, the controller 90 waits until the X position becomes the machining start position D or less while inputting the X position from the X direction position detection circuit 44, and the X position becomes the machining start position D or less. Then, in step S188, an irradiation start command for the non-processing laser beam is output to the pulse signal supply device 50. As a result, the pulse signal supply device 50 starts outputting a DC signal set at a low level instead of the pulse train signal. Thus, the laser processing is interrupted once. Therefore, pits are formed in a straight line at predetermined intervals between the machining start position D ′ and the machining start position D.

  Subsequently, in steps S190 and S192, the controller 90 waits until the X position becomes the hold switching position C or less while inputting the X position from the X direction position detection circuit 44, and the X position becomes the hold switching position C or less. In step S194, a focus servo control hold command signal is output to the mask signal generation circuit 66. Thereby, the focus servo control is held. Subsequently, in Steps S196 and S198, the controller 90 waits until the X position becomes equal to or less than the constant velocity movement position B while inputting the X position from the X direction position detection circuit 44, and the X position becomes the constant velocity movement position B. In step S200, an instruction to stop the movement of the stage 21 in the X negative direction is output to the X direction feed motor control circuit 42 in step S200. The X direction feed motor control circuit 42 stops driving the X direction feed motor 22 based on this command. In this case as well, the vehicle is stopped at the stop position A in order to decelerate and stop.

  Subsequently, in step S202, the controller 90 increments the value of the variable n by “1”. In step S204, it is determined whether or not the Y position (S + n · p) exceeds the end position E. If the Y position (S + n · p) does not exceed the end position E, a movement command to the Y position (S + n · p) is output to the Y-direction feed motor control circuit 43 in step S210. Based on this command, the Y-direction feed motor control circuit 43 performs the Y-direction feed motor until the Y position detected by the Y-direction position detection circuit 45 becomes equal to the Y position (S + n · p) specified by the movement command. Rotate. Subsequently, in steps S212 and S214, the controller 90 waits until the Y position becomes equal to the Y position (S + n · p) while inputting the Y position from the Y-direction position detection circuit 45, and the Y position becomes the Y position ( When S + n · p) is reached, the process returns to step S128.

  Therefore, by repeating such processing, pits are formed linearly in the X direction at predetermined intervals between the machining start positions DD ′, and a plurality of pit rows are formed in the Y direction at intervals of the feed pitch p. It will be done. Thus, when performing laser processing by reciprocating the laser light irradiation position, the focus servo control is held outside the hold switching position C-C '. Accordingly, even when the moving stroke range in the X direction of the laser beam irradiation position deviates from the surface of the workpiece OB and the laser beam focusing position and the laser beam irradiation surface deviate greatly, the focus servo control is performed. Does not come off. For this reason, even if focus servo control is resumed immediately before the start of laser processing, it is possible to perform appropriate focus servo control between the processing start positions D and D ′.

  When such laser processing is repeated, the processing area expands in the Y direction. If the Y position (S + n · p) detected by the Y-direction position detection circuit 45 exceeds the end position E, “No” is determined in step S162 or step S204. Based on this determination, the controller 90 outputs a focus servo control hold release command signal to the mask signal generation circuit 66 in step S163, and outputs a focus servo control stop command to the focus servo circuit 63 in step S164. In step S165, a laser beam irradiation stop command is output to the pulse signal supply device 50 and the laser driving circuit 70. Thereby, the irradiation of the laser beam (laser beam having non-processing intensity) is stopped. In this way, laser processing is performed on the entire processing region set in advance on the surface of the processing object OB. When the controller 90 outputs the laser beam irradiation stop command, the laser processing control routine is terminated in step S166.

  In such laser processing, each processing set position (target position for forming a pit) is irradiated with processing intensity laser light by irradiation with a processing pulsed laser beam, and a position different from the processing setting position (adjacent pits). In the meantime, a pit is formed when there is a time delay from the detection of the processing start positions D and D ′ to the start of the emission of the processing laser beam. As a result, the position to be processed deviates from the machining setting position as a whole. Therefore, the controller 90 performs timing adjustment processing in parallel with the laser processing control routine.

  The timing adjustment processing detects a delay from the timing at which the processing start position D is detected to the timing at which the laser light with the processing intensity is actually emitted from the laser light source 31, and based on this delay, the pulse signal supply device 50 is detected. Is a process of adjusting the output period of one low-level signal in the pulse train signal output from, and thereafter irradiating the processing set position with laser light of processing intensity. 5A and 5B show a timing adjustment routine executed by the controller 90. FIG. The timing adjustment routine is stored as a control program in the ROM of the controller 90 and is activated simultaneously with the activation of the laser processing control routine described above.

  When the timing adjustment routine is started in step S300, the controller 90 waits until the X position becomes equal to or less than the hold switching position C while inputting the X position from the X direction position detection circuit 44 in steps S302 and S304. When it is detected that the X position is equal to or lower than the hold switching position C (S304: Yes), the X position is input from the X-direction position detection circuit 44 in the subsequent steps S306 and S308, and the X position becomes the machining start position D. Until a position (D−α) that is less by the detection unit distance α is reached. At the time of this standby, simultaneously with the confirmation of the X position, it is determined whether or not a laser irradiation stop command is output in step S310. That is, it is determined whether or not the command in step S165 in the laser processing control routine has been output.

  The detection unit distance α is a movement distance from when the X-direction position detection circuit 44 outputs the X position detection signal to when the next X position detection signal is output. This detection unit distance α can be expressed as α = SP × T, where T is the period at which the X-direction position detection circuit 44 outputs the X-position detection signal and SP is the X-direction moving speed of the laser light irradiation position.

  During this standby, the laser beam irradiation position moves in the X negative direction from the hold switching position C to the stop position A (in the case of the first processing, the stop position A becomes the start point St), and then At the stop position A, the moving direction is reversed. When the irradiation position of the laser beam in the X direction becomes equal to or greater than the position (D−α) that is a detection unit distance α from the processing start position D, the controller 90 performs a signal input detection circuit 80 in a subsequent step S314. An operation start command is output.

  In the laser processing control routine described above, when the laser beam irradiation position moves in the X positive direction, the controller 90 outputs a pulse train signal output command to the pulse signal supply device 50 at the timing when the processing start position D is detected. Is output. Therefore, when the X position (D-α) is detected in step S308, the pulse train signal is not yet output from the pulse signal supply device 50 to the laser driving circuit 70. When the laser beam irradiation position further moves in the X positive direction by the detection unit distance α, the X direction position detection circuit 44 outputs digital data representing the machining start position D to the controller 90 and the signal input detection circuit 80. As a result, the signal input detection circuit 80 outputs a high-level signal input detection signal (one pulse signal) indicating that the signal has been input to the delay signal generation circuit 81. The pulse signal supply device 50 outputs a pulse train signal to the laser drive circuit 70 in response to a pulse train signal output command from the controller 90. Thereby, a pulsed laser beam for processing is emitted from the laser light source 31.

  When the signal output from the signal input detection circuit 80 becomes high level, the delay signal generation circuit 81 sets its output to high level, and the signal output from the signal amplification circuit 71 changes to high level (laser light having a processing intensity is emitted). When it reaches the level when it is irradiated, its output is switched from the high level to the low level. Therefore, during the period when the signal generated by the delay signal generation circuit 81 is at a high level, the delay from the timing when the X-direction position detection circuit 44 detects the machining start position D to the timing when the intensity of the laser beam is switched to the machining intensity. It corresponds to time. Hereinafter, this delay time is referred to as timing deviation Dev. The A / D converter 82 converts the signal generated by the delay signal generation circuit 81 into a digital signal and outputs it to the controller 90.

In step S316, the controller 90 inputs data from the A / D converter 82. In step S318, the controller 90 calculates a time when the signal generated by the delayed signal generation circuit 81 is at a high level as a timing shift Dev. To do. Subsequently, in step S320, the controller 90 sets a time width Lt (output period of the low level signal LS) of one low level signal LS in the pulse train signal output from the pulse signal supply device 50 by the following equation (1). .
Lt = Lt−Dev (1)
Here, Lt on the right side is the time width of the low level signal LS stored in the pulse signal supply device 50. Therefore, the time width Lt of the specific low level signal LS in the pulse train signal is set to be shorter by the timing shift Dev. In the present embodiment, as shown in FIG. 2, the time width Lt of the low-level signal LS of the pulse train signal in the second cycle, which is the next cycle of the timing at which the machining start position D is detected, is shortened by the timing deviation Dev. Although it is set, it is preferable to adjust the time width Lt of the low level signal LS at the earliest possible time after the timing shift Dev is detected.

  Subsequently, in Steps S322 and S324, the controller 90 waits until the X position becomes equal to or higher than the hold switching position C ′ while inputting the X position from the X direction position detection circuit 44. During this standby, the laser processing control routine emits a processing pulse laser beam from the laser light source 31, and pits are formed in the positive X direction at predetermined intervals on the surface of the processing object OB. At the time of this laser processing, since the time width Lt of the second period of the low level signal LS in the pulse train signal is set to be short by the timing deviation Dev, from the laser light irradiation by the high level signal HS of the third period, Pits (processing marks) can be formed correctly at the laser irradiation setting position (processing setting position).

  Here, the adjustment of the irradiation timing of the processing-intensity laser beam will be described with reference to FIG. 6A and 6B are signal waveform diagrams when laser processing is started in the X positive direction. FIG. 6A is an X position detection signal (digital signal) output from the X direction position detection circuit 44, and FIG. An operation start command signal output to the signal input detection circuit 80, (c) is a signal output from the signal amplification circuit 71 (emission intensity of laser light), and (d) is a waveform of a pulse signal output from the delay signal generation circuit 81. To express.

  When the X position (D-α) is detected by the X direction position detection circuit 44 at time t1 (S308: Yes), an operation start command is output from the controller 90 to the signal input detection circuit 80 at time t2. When the machining start position D is detected by the X-direction position detection circuit 44 at time t3, a pulse train signal output command is output from the controller 90 to the pulse signal supply device 50 (S140) and signal input is performed. The detection circuit 80 outputs a high-level signal input detection signal (one pulse signal) to the delay signal generation circuit 81. The pulse signal supply device 50 outputs a pulse train signal to the laser drive circuit 70, and the laser drive circuit 70 supplies a laser drive signal to the laser light source 31 according to the input pulse train signal. Thus, irradiation of the processing pulsed laser light is started at time t4. Therefore, the elapsed time from time t3 to time t4 corresponds to a delay time, that is, a timing deviation Dev.

  In step S320, the controller 90 sets the time width Lt of the second-level low level signal LS in the pulse train signal to be shorter by the timing deviation Dev. Therefore, the timing shift Dev that occurred at time t5 in FIG. 6 becomes zero at time t6. That is, it is possible to irradiate the laser irradiation setting position with laser light having a processing intensity.

  Returning to the description of the timing adjustment routine of FIG. When the controller 90 detects in step S324 that the X position is equal to or greater than the hold switching position C ′, the controller 90 inputs the X position from the X direction position detection circuit 44 in the subsequent steps S326 and S328, and the X position is processed. It waits until it becomes below the position (D '+ (alpha)) which added detection unit distance (alpha) to the starting position D'. At the time of this standby, simultaneously with the confirmation of the X position, it is determined whether or not a laser irradiation stop command is output in step S330. During this time, the laser beam irradiation position is moved in the X positive direction from the hold switching position C ′ to the stop position A ′ by the laser processing control routine, and moved by the feed pitch p in the Y direction at the stop position A ′. Start moving in the X negative direction.

  When the X position becomes equal to or smaller than the position (D ′ + α), the determination in step S328 is “Yes”, and the controller 90 outputs an operation start command to the signal input detection circuit 80 in step S334. Subsequently, in step S336, the controller 90 inputs data from the A / D converter 82. In step S338, the controller 90 delays the time when the signal generated by the delayed signal generation circuit 81 is at the high level. Calculate as Dev.

  In step S334, when the X position becomes equal to or less than the position (D ′ + α), the pulse train signal has not yet been output from the pulse signal supply device 50 to the laser driving circuit 70. When the laser light irradiation position further moves in the X negative direction by the detection unit distance α, the X direction position detection circuit 44 outputs digital data representing the machining start position D ′ to the controller 90 and the signal input detection circuit 80. . As a result, the signal input detection circuit 80 outputs a high-level signal input detection signal to the delay signal generation circuit 81. The pulse signal supply device 50 outputs a pulse train signal to the laser drive circuit 70 in response to a pulse train signal output command from the controller 90. Thereby, a pulsed laser beam for processing is emitted from the laser light source 31. Thus, the delay signal generation circuit 81 generates a pulse signal having a time width corresponding to the delay time from the timing when the X-direction position detection circuit 44 detects the machining start position D ′ to the timing when the intensity of the laser beam switches to the machining intensity. Output.

  When the controller 90 calculates the timing deviation Dev in step S338, in the subsequent step S340, the time width Lt of the low-level signal LS in the second period in the pulse train signal output from the pulse signal supply device 50 is shortened by the timing deviation Dev. Set (Lt = Lt−Dev). When executing the process of step S340, the controller 90 returns the process to step 302. Thereby, the process described above is repeated. If it is detected in step S310 or step S330 that a laser irradiation stop command has been output, the timing adjustment routine is terminated in step S312.

  According to the laser processing apparatus 1 of the present embodiment described above, the irradiation position of the laser beam is reciprocated in the X direction including the processing area, and is fed and moved in the Y direction at both ends of the reciprocation movement in the X direction. Laser processing is performed with. Then, every time the laser light irradiation position enters the machining area from the machining start positions D and D ′, the timing deviation Dev is detected, and the time width Lt of one low level signal LS in the pulse train signal is shortened by the timing deviation Dev. In order to set, thereafter, laser light having a processing intensity can be irradiated at a laser irradiation setting position (processing setting position). Thereby, the positions of the pits in the pit rows adjacent in the Y direction can be aligned. As a result, for example, nano-order fine pits can be accurately arranged in a square shape or a hexagonal close-packed shape, and a high-quality LED substrate or liquid crystal substrate can be manufactured.

  If the machining start positions D and D ′ are different from the position X where the X-direction position detection circuit 44 can output the X position detection signal within a negligible range, the difference values (X−D), ( A value obtained by adding (X−D) / SP and (D′−X) / SP to the timing shift Dev may be used as the timing shift Dev using D′−X). In this case, pits can be formed at the machining setting position with higher accuracy.

  Next, a modified example of the timing adjustment routine in the above-described embodiment will be described. In the above-described embodiment, the timing deviation Dev is detected at the machining start positions D and D ′, and the time width Lt of one low level signal LS is adjusted based on the timing deviation Dev. In this case, it is required to move the stage 21 at a constant speed in the X direction with high accuracy. If the stage 21 cannot be moved at a constant speed (moving at a constant speed) with high accuracy, the pit formation position may deviate from the machining setting position. Therefore, in the modification, in addition to the processing start positions D and D ′, the timing deviation Dev is detected and the time width Lt of one low level signal LS is adjusted each time the laser beam irradiation position moves by the distance W. Thus, even in the stage drive device 20 that does not have high constant velocity movement performance, the pit formation position is adjusted to the machining setting position with high accuracy.

  The timing adjustment routine according to the modification is obtained by adding the process shown in FIG. 7 between step S320 and step S322 of the timing adjustment routine of the above-described embodiment, and adding the process shown in FIG. 8 after step S340. is there. Hereinafter, this additional process will be described.

  When the controller 90 sets the time width Lt of one low level signal LS in the pulse train signal in step S320, the controller 90 sets the value of the variable m to “1” in the subsequent step S321-1. Subsequently, in steps S321-2 and S321-3, while the X position is input from the X direction position detection circuit 44, the process waits until the X position becomes equal to or greater than the position (D + m · W−α). Here, W is the moving distance of the laser beam irradiation position in one cycle when periodically detecting the timing deviation Dev. This distance W is set to an integral multiple of the detection unit distance α. At the time of standby, at the same time as confirming the X position, it is determined whether or not a laser irradiation stop command is output in step S321-10.

  When the X position becomes equal to or greater than the position (D + m · W−α), the controller 90 outputs an operation start command to the signal input detection circuit 80 in step S321-4. Subsequently, in step S321-5, the controller 90 inputs data from the A / D converter 82, and in step S321-6, the signal generated by the delayed signal generation circuit 81 becomes a high level from this data. The time is calculated as the timing deviation Dev.

  As described above, in the timing adjustment routine, the timing deviation Dev is detected at the machining start position D, and the time width Lt of one low level signal LS in the pulse train signal is set shorter by the timing deviation Dev. Although the irradiation timing of the intense laser beam is adjusted, if the stage 21 cannot be moved at a constant speed with high accuracy, the irradiation position of the laser beam may deviate from the set position after the irradiation timing is adjusted. Therefore, in the timing adjustment routine of this modification, the time from when the position (D + m · W) is detected by the X-direction position detection circuit 44 to when the laser beam with the processing intensity is actually irradiated, that is, the timing. The deviation Dev is obtained from the time when the output signal of the delay signal generation circuit 81 becomes high level.

  When the controller 90 calculates the timing shift Dev in step S321-6, in step S321-7, the controller 90 shifts the time width Lt of the low level signal LS in the next cycle in the pulse train signal output from the pulse signal supply device 50. Only Dev is set short (Lt = Lt−Dev). Subsequently, in step S321-8, it is determined whether or not the X position detected by the X direction position detection circuit 44 is equal to or greater than the position (D'-W). If the X position is less than the position (D′−W), the value of the variable m is incremented by “1” in step S321-9, and the process returns to step S321-10.

  Thereby, every time the laser beam irradiation position moves by the distance W, the timing shift Dev is detected, and the time width Lt of the low level signal LS in the pulse train signal is adjusted. When the X position is equal to or greater than the position (D'-W), the routine shown in FIG. 7 is exited and the processing from step S322 described above is performed. In addition, when an output of a laser irradiation stop command is detected during such processing (S321-10: Yes), the timing adjustment routine ends.

  Next, processing added after step S340 will be described with reference to FIG. The process in FIG. 7 described above is a process when the laser beam irradiation position moves in the X positive direction, but the process in FIG. 8 is a process when the laser beam irradiation position moves in the X negative direction. Since the X-coordinate position is different from the process of FIG.

  When the controller 90 sets the time width Lt of one low level signal LS in the pulse train signal in step S340, the controller 90 sets the value of the variable m to “1” in subsequent step S341. Subsequently, in steps S342 and S343, while the X position is input from the X direction position detection circuit 44, the process waits until the X position becomes equal to or less than the position (D−m · W + α). When the X position becomes equal to or less than the position (D−m · W + α), the controller 90 outputs an operation start command to the signal input detection circuit 80 in step S344, and the data from the A / D converter 82 in step S345. In step S346, the timing deviation Dev is calculated. Subsequently, in step S347, the time width Lt of the low-level signal LS in the next cycle in the pulse train signal output from the pulse signal supply device 50 is set to be shorter by the timing shift Dev (Lt = Lt−Dev). Subsequently, in step S348, it is determined whether or not the X position detected by the X direction position detection circuit 44 is equal to or less than the position (D + W). If the X position is larger than the position (D + W), the value of the variable m is incremented by “1” in step S349, and the process returns to step S350.

  Thereby, even when the laser beam irradiation position moves in the X negative direction, the timing deviation Dev is detected every time the laser beam irradiation position moves by the distance W, and the time width Lt of the low level signal LS in the pulse train signal is adjusted. Is done. When the X position becomes equal to or less than the position (D + W), the routine shown in FIG. 8 is exited and the processing from step S302 described above is performed. In addition, when an output of a laser irradiation stop command is detected during such processing (S350: Yes), the timing adjustment routine ends.

  Here, the adjustment of the irradiation timing of the processing-intensity laser light will be described with reference to FIG. FIG. 9 is a signal waveform diagram when laser processing is started in the positive X direction. FIGS. 9A, 9B, 6C, and 9D are the waveforms (a), (b), (d) in FIG. It is the same signal waveform as c) and (d). As shown from time t1 to time t6, the timing shift Dev1 that has occurred at the machining start position D is set by shortening the time width Lt of the low-level signal LS in the second period in the pulse train signal by the timing shift Dev1. It becomes zero at time t6. Therefore, after that, even if the laser processing by the processing pulse laser beam proceeds in the X positive direction, the laser beam having the processing intensity should be irradiated to the laser irradiation setting position. However, there is a case where the position where the processing intensity laser beam is irradiated deviates from the laser irradiation setting position because the moving speed of the stage 21 slightly changes.

  In such a case, the irradiation position of the processing-intensity laser light may be shifted in the X positive direction or the X negative direction from the laser irradiation setting position. That is, there is a case where the irradiation timing of the processing laser light is delayed or advanced from the set timing. In order to cope with such a situation, in the timing adjustment routine of the modified example, the laser beam irradiation timing is periodically adjusted. The example shown from time t7 to time t11 represents timing adjustment when the irradiation timing of the processing laser light is delayed from the setting timing, and the example shown from time t12 to time t17 is set with the irradiation timing of the processing laser light. It represents timing adjustment when the timing is earlier than the timing.

  At time t7, an X position that is a detection unit distance α before the second timing deviation detection position (D + W) is detected. At time t8, an operation start command is output from the controller 90 to the signal input detection circuit 80, and at time t9, the X-direction position detection circuit 44 detects the laser irradiation setting position (D + W). In this example, since the irradiation timing of the processing laser beam is delayed, the laser beam having the processing intensity is detected at time t10. Therefore, the time from time t9 to time t10 is a timing shift Dev2. In this case, the time width Lt of the low level signal LS of the next period in the pulse train signal is set to be shorter by the timing shift Dev2. As a result, at time t11, the laser irradiation setting position is irradiated with laser light having a processing intensity.

At time t12, an X position that is a detection unit distance α before the third timing deviation detection position (D + 2W) is detected. Then, at time t <b> 14, an operation start command is output from the controller 90 to the signal input detection circuit 80. In this example, since the irradiation timing of the processing laser light is earlier, the laser having the processing intensity from time t13 earlier than time 15 at which the laser irradiation setting position (D + 2W) is detected by the X-direction position detection circuit 44. Since the light is detected, the delay signal generation circuit 81 outputs a high level signal until time t16 when the next irradiation of the laser beam having the processing intensity is detected. In this case, the timing deviation Dev3 can be calculated as follows.
Dev3 = T2-T1
Here, T2 is a time width during which the delayed signal generation circuit 81 outputs a high level signal, and T1 is a period (Ht + Lt) of a pulse train signal output from the pulse signal supply device 50. In this case, the timing deviation Dev3 is a negative value. Therefore, when the time width Lt of the low-level signal LS of the next period in the pulse train signal is adjusted by the timing shift Dev3, the adjusted time width Lt becomes longer than the original time width Lt. As a result, at time t17, the laser beam having the processing intensity is irradiated to the laser irradiation setting position.

  According to the timing adjustment routine according to the modified example described above, every time it is detected that the laser beam irradiation position has reached the timing deviation detection position (D + m · W), the timing deviation Dev is detected, and the low level in the pulse train signal is detected. Since the time width Lt of the level signal LS is adjusted, the pit can be formed at the machining setting position even if the accuracy of moving the stage 21 at a constant speed in the X direction is not high. As a result, the stage driving device 20 is not required to have a high constant velocity movement performance, so that both improvement in machining accuracy and cost reduction can be achieved. The timing deviation detection position (D + m · W) corresponds to the specific machining setting position in the present invention.

  It should be noted that the irradiation start setting positions (D + m · W) and (D′−m · W) of the processing pulse laser beam are within a range that can be ignored from the position X where the X-direction position detection circuit 44 can output the X position detection signal. In the case where there is a difference, the difference value (X− (D + m · W)), ((D′−m · W) −X) is used to set the timing deviation Dev to (X− (D + m · W). ) / SP, ((D′−m · W) −X) / SP may be added as a timing shift Dev. In this case, pits can be formed at a set position with higher accuracy.

  Next, a second embodiment will be described. The above-described embodiment (including modifications) is referred to as a first embodiment, and the embodiment described below is referred to as a second embodiment. The second embodiment differs from the first embodiment in the laser processing control routine executed by the controller 90, the timing adjustment routine, and the pulse signal data stored in the pulse signal supply device 50. Is the same as in the first embodiment.

  In the first embodiment, information for generating a pulse train signal is stored in the pulse signal supply device 50, and when a laser processing start command is input from the controller 90, an analog pulse train signal in which the pulse signals for one cycle are made continuous. Is generated and output to the laser driving circuit 70. That is, after the laser processing start command is input from the controller 90, the processing pulse laser beam is continuously irradiated. On the other hand, in the second embodiment, the pulse signal information for one pulse is stored in the pulse signal supply device 50, and the controller is detected each time it is detected that the laser beam irradiation position has approached the machining setting position. A configuration is adopted in which a pulse signal output command is output from 90 to the pulse signal supply device 50 and a laser drive signal is supplied to the laser light source 31.

  The pulse signal supply device 50 starts outputting a low-level DC signal when a laser irradiation start command of non-processing intensity is output in response to a command from the controller 90. Only when a pulse signal output command is received from the controller 90, one pulse signal having a waveform stored in the memory 50a is output each time. That is, a pulse signal is output between the low-level DC signals. The pulse signal is not a mere high-level rectangular wave, but includes a period in which the pulse signal is at a low level. This low level period (referred to as a low level period Lp) is provided at the head of the pulse signal. That is, as shown in FIG. 10, the pulse signal is composed of a low-level signal output first and a high-level signal output thereafter, forming one pulse signal. The intensity of the pulse signal in the low level period Lp is the same intensity as the direct current low level signal when the pulse signal is not output. Therefore, although the pulse signal supply device 50 outputs a pulse signal in response to a command from the controller 90, the output state is immediately after that, that is, until the low level period Lp elapses from the time when the pulse signal is output. It does not change. Therefore, a high level signal is output to the laser driving circuit 70 with a delay of the low level period Lp.

  The pulse signal supply device 50 inputs in advance digital data representing the signal intensity in the high level period Hp, the length of the high level period Hp, and the signal intensity in the low level period Lp from the controller 90 as pulse signal information. It is stored in the memory 90a. When information indicating the length of the low level period Lp (this length is simply referred to as the low level period Lp) is input from the controller 90 during laser processing, a pulse corresponding to one pulse composed of the low level and the high level. Waveform digital data is created and stored in the memory 50a. If no information indicating the low level period Lp is input from the controller 90, digital data having a pulse waveform with the low level period Lp set to zero (Lp = 0) is generated and stored in the memory 50a.

  Next, a laser processing control routine in the second embodiment will be described. The laser processing control routine in the second embodiment performs the process shown in FIG. 11 instead of steps S140 to S146 of the laser processing control routine (FIG. 4) in the first embodiment, and replaces steps S182 to S188. 12 is performed. Hereinafter, processing different from that of the first embodiment will be described with reference to FIGS. 11 and 12.

  When the laser beam irradiation position advances in the X positive direction from the start point St and the X position detected by the X direction position detection circuit 44 reaches the machining start position D, the controller 90 notifies the pulse signal supply device 50 in step S501. In response to this, a pulse signal output command is output. As a result, the pulse signal supply device 50 outputs one pulse signal having a waveform stored in the memory 50 a to the laser driving circuit 70. The pulse signal output from the pulse signal supply device 50 is composed of a low level signal and a high level signal output thereafter. The pulse signal output from the pulse signal supply device 50 in step S501 will be described later. The low level period Lp is set to zero by the timing adjustment routine. Therefore, the laser drive circuit 70 outputs a processing laser drive signal to the laser light source 31 in accordance with the high-level pulse signal output from the pulse signal supply device 50. Thus, one pit is formed on the surface of the workpiece OB by the output of one pulse signal.

  Subsequently, in step S502, the controller 90 sets the value of the variable k to “1”. Subsequently, in steps S503 and S504, while the X position is input from the X direction position detection circuit 44, the process waits until the X position becomes equal to or greater than the position (D + k · p−α−Dev · SP). Here, p represents a machining pitch in the X direction, that is, a pit formation interval, k represents an integer (1, 2, 3,...), Α represents an X position detection signal by the X direction position detection circuit 44. This represents a detection unit distance that is an output position interval, Dev represents a timing deviation set by a timing adjustment routine described later, and SP represents an X-direction moving speed of the laser light irradiation position.

  In this case, since k = 1 is set, it is determined that the position has reached a position that is a predetermined distance (α + Dev · SP) ahead of the point advanced by the machining pitch p in the positive X direction from the machining start position D. It will be. When the X position detected by the X direction position detection circuit 44 becomes equal to or greater than the position (D + k · p−α−Dev · SP) (S504: Yes), the controller 90 sends the pulse signal supply device 50 to the pulse signal supply device 50 in step S505. In contrast, an output command for the second pulse signal is output. This position (D + k · p−α−Dev · SP) corresponds to the light emission command position in the present invention. Thereby, a second pit is formed on the surface of the workpiece OB.

  This step S505 is repeatedly executed as will be described later, and each time a pulse signal output command is output to the pulse signal supply device 50, the timing deviation from the third pulse signal is performed by a timing adjustment routine described later. This is a signal in which a low level period Lp corresponding to Dev is set. The intensity of the pulse signal in the low level period Lp is the same intensity as the low level signal (DC signal) when the pulse signal is not output. For this reason, during the low level period Lp of the pulse signal output by the pulse signal supply device 50, the non-processing laser drive signal is continuously output from the laser drive circuit 70 to the laser light source 31. When the low level period Lp ends and the level is switched to the high level, the laser drive circuit 70 outputs a processing laser drive signal to the laser light source 31. When the pulse signal output period (Lp + Hp) elapses, the pulse signal supply device 50 starts outputting a low-level DC signal again. Accordingly, the timing at which the laser beam having the processing intensity is emitted from the laser light source 31 is delayed by the low level period Lp.

  Subsequently, in step S506, the controller 90 increments the value of the variable k by “1”. Subsequently, in step S507, it is determined whether or not the X position (D + k · p) obtained by adding the distance k · p to the machining start position D is larger than the machining start position D ′. That is, it is determined whether or not laser processing has progressed to the boundary of the X coordinate in the processing region. When the controller 90 determines that the X position (D + k · p) is equal to or less than the machining start position D ′ (S507: No), the process returns to step S503. Therefore, every time it is detected that the X position is equal to or greater than the position (D + k · p−α−Dev · SP), a pulse signal output command is output to the pulse signal supply device 50. Then, every time a pulse signal is output from the pulse signal supply device 50, the processing object OB is irradiated with laser light having an intensity corresponding to the level of the pulse signal.

  When these processes are repeated and the X position (D + k · p) becomes larger than the machining start position D ′, the controller 90 determines “Yes” in step S507 and advances the process to step S148.

  Next, processing performed instead of steps S182 to S188 in the laser processing control routine will be described with reference to FIG. The process in FIG. 11 described above is a process when the laser beam irradiation position moves in the X-positive direction in the machining area. However, the process in FIG. 12 moves the laser beam irradiation position in the X-negative direction in the machining area. Since the X coordinate position is different from the process of FIG. 11, only a brief description will be given.

  When the laser beam irradiation position advances from the stop position A ′ in the X negative direction and the X position detected by the X direction position detection circuit 44 reaches the machining start position D ′, the controller 90 supplies a pulse signal supply device in step S511. 50, a pulse signal output command is output. As a result, the pulse signal supply device 50 outputs one pulse signal having a waveform stored in the memory 50 a to the laser driving circuit 70. Thus, the first pit in the second row is formed on the surface of the workpiece OB. Note that the low level period Lp of the pulse signal output from the pulse signal supply device 50 in step S511 is set to zero by a timing adjustment routine described later.

  Subsequently, in step S512, the controller 90 sets the value of the variable k to “1”. Subsequently, in steps S513 and S514, while the X position is input from the X direction position detection circuit 44, the process waits until the X position becomes equal to or less than the position (D′−k · p + α + Dev · SP). When the X position detected by the X direction position detection circuit 44 becomes equal to or less than the position (D + k · p−α−Dev · SP) (S514: Yes), the controller 90 sends the pulse signal supply device 50 to the pulse signal supply device 50 in step S515. In response to this, a pulse signal output command is output.

  Subsequently, the controller 90 increments the value of the variable k by “1” in step S516, and in the subsequent step S517, subtracts the distance k · p from the machining start position D ′ (D′−k · p ) Is smaller than the machining start position D. If the X position ((D′−k · p) has not reached the machining start position D ′, the controller 90 returns the processing to step S513. Accordingly, the X position is the position (D + k · p−α−). Dev / SP) every time it is detected that the pulse signal is less than or equal to Dev / SP), a pulse signal output command is output to the pulse signal supply device 50, and laser light having an intensity corresponding to the level of the pulse signal is applied to the workpiece OB. In this case, in step S515, the low-level period Lp corresponding to the timing deviation Dev is set from the third pulse signal by a timing adjustment routine described later. The timing at which laser light having a processing intensity is emitted from the laser light source 31 is delayed by Lp.

  When such processing is repeated and the X position (D′−k · p) becomes smaller than the machining start position D, the controller 90 determines “Yes” in step S517, and advances the processing to step S190. . In the second embodiment as well, the pulse signal is high when the laser beam irradiation position goes out of the machining area from the machining start position D and when the laser beam irradiation position goes out of the machining area from the machining start position D ′. The level period Hp is set to be exactly the end timing.

  Next, a timing adjustment routine in the second embodiment will be described. In this timing adjustment routine, the controller 90 sets the low level period Lp in the pulse signal output from the pulse signal supply device 50 to the laser drive circuit 70. 13A to 13C represent a timing adjustment routine executed by the controller 90. FIG. The timing adjustment routine is stored as a control program in the ROM of the controller 90, and is performed in parallel with the laser processing control routine.

  When the timing adjustment routine starts in step S600, the controller 90 sets the value of the variable s to “1” in step S602. Subsequently, in steps S604 and S606, while the X position is input from the X direction position detection circuit 44, the process waits until the X position becomes equal to or less than the hold switching position C. When it is confirmed that the X position is equal to or lower than the hold switching position C (S606: Yes), the X position is input to the machining start position D while the X position is input from the X direction position detection circuit 44 in subsequent steps S608 and S610. Until a position (D−α) that is less by the detection unit distance α is reached. At the time of this standby, simultaneously with the confirmation of the X position, it is determined whether or not a laser irradiation stop command is output in step S612. That is, it is determined whether or not the command in step S163 in the laser processing control routine has been output.

  During this standby, the laser beam irradiation position moves in the X negative direction from the hold switching position C to the stop position A (in the case of the first processing, the stop position A becomes the start point St), and then At the stop position A, the moving direction is reversed. When the irradiation position of the laser beam in the X direction becomes equal to or greater than the position (D−α) before the processing start position D by the detection unit distance α, the controller 90 operates on the signal input detection circuit 80 in step S616. Output a start command.

  In the laser processing control routine described above, when the laser beam irradiation position moves in the X positive direction, the controller 90 issues a pulse signal output command to the pulse signal supply device 50 at the timing when the processing start position D is detected. Is output (S501). Therefore, when the X position (D-α) is detected in step S610, the pulse signal is not yet output from the pulse signal supply device 50 to the laser driving circuit 70. When the laser beam irradiation position further moves in the X positive direction by the detection unit distance α, the X direction position detection circuit 44 outputs digital data representing the machining start position D to the controller 90 and the signal input detection circuit 80. As a result, the signal input detection circuit 80 outputs a high-level signal input detection signal (one pulse signal) indicating that the signal has been input to the delay signal generation circuit 81. Further, the pulse signal supply device 50 outputs a pulse signal to the laser drive circuit 70 in response to a pulse signal output command from the controller 90. As a result, laser light having a processing intensity is emitted from the laser light source 31. At this time, since the setting command for the low level period Lp of the pulse signal is not output from the controller 90 to the pulse signal supply device 50, the low level period Lp of the pulse signal output from the pulse signal supply device 50 becomes zero. ing.

  When the signal output from the signal input detection circuit 80 becomes high level, the delay signal generation circuit 81 sets its own output to high level, and the signal output from the signal amplification circuit 71 changes from low level to high level (the processing intensity level). When the level is switched to the level when the laser beam is irradiated, the output is switched from the high level to the low level. Therefore, during the period when the signal generated by the delay signal generation circuit 81 is at a high level, the delay from the timing when the X-direction position detection circuit 44 detects the machining start position D to the timing when the intensity of the laser beam is switched to the machining intensity. It represents a timing shift Dev that is time. The A / D converter 82 converts the signal generated by the delay signal generation circuit 81 into a digital signal and outputs it to the controller 90.

  In step S618, the controller 90 inputs data from the A / D converter 82. In step S620, the controller 90 calculates the time when the signal generated by the delayed signal generation circuit 81 is at a high level as a timing shift Dev. To do. Subsequently, in steps S622 and S624, the controller 90 waits until the X position becomes equal to or greater than the position (D + s · p−α−Dev · SP) while inputting the X position from the X direction position detection circuit 44. In this case, since s = 1 is set, it is determined that the position has reached a position that is a predetermined distance (α + Dev · SP) ahead of the point advanced by the machining pitch p in the X positive direction from the machining start position D. It will be. The position at which the X position is detected to be equal to or greater than the position (D + s · p−α−Dev · SP) is determined by the controller 90 when the second and subsequent pits are formed in step S505 of the laser processing control routine. This is the position where the signal supply device 50 is commanded to output a pulse signal.

When the controller 90 detects that the X position is equal to or greater than the position (D + s · p−α−Dev · SP) in step S624, the controller 90 calculates an integer Nn by the following equation in step S626.
Nn = INT {(position (D + (s + 1) · p-Dev · SP) −position X) / α}
Here, INT represents a function for obtaining an integer part of a calculated value in parentheses {}.

Subsequently, in step S628, the controller 90 calculates the low level period Lp by the following equation.
Lp = {(position (D + (s + 1) · p) −position (X + Nn · α)) / SP} −Dev
Subsequently, in Step S630, the controller 90 sets the low level period Lp by outputting information indicating the calculated low level period Lp to the pulse signal supply device 50.

  The processing in steps S626 to S630 includes the position where the X position detection signal is output from the X direction position detection circuit 44 before the next machining setting position (D + (s + 1) · p), and the machining setting position (D + (s + 1). The time obtained by subtracting the timing deviation Dev from the time obtained by dividing the difference from) · p) by the moving speed SP is set as the low level period Lp.

  Subsequently, in Step S632, the controller 90 determines whether or not the X position (D + s · p) is larger than the machining start position D ′. If the X position (D + s · p) is equal to or smaller than the machining start position D ′, the value of the variable s is incremented by “1” in step S634, the process returns to step S622, and the process described above. repeat. Thus, every time it is detected that the X position is equal to or greater than the position (D + s · p−α−Dev · SP), the laser beam having the processing intensity is set at the next processing set position (D + (s + 1) · p). A low-level period Lp of the pulse signal for irradiating is set. As a result, it is possible to irradiate laser light having a processing intensity at an appropriate timing, and it is possible to form pits (processing marks) at respective processing setting positions.

  Here, the adjustment of the irradiation timing of the processing-intensity laser light will be described with reference to FIG. 14A and 14B are signal waveform diagrams when laser processing is started in the X positive direction. FIG. 14A is an X position detection signal (digital signal) output from the X direction position detection circuit 44, and FIG. An operation start command signal output to the signal input detection circuit 80, (c) is a signal output from the signal amplification circuit 71 (emission intensity of laser light), and (d) is a waveform of a pulse signal output from the delay signal generation circuit 81. To express.

  When the X position (D−α) is detected by the X direction position detection circuit 44 at time t1 (S610: Yes), the controller 90 outputs an operation start command to the signal input detection circuit 80 at time t2. When the machining start position D is detected by the X direction position detection circuit 44 at time t3, the controller 90 outputs a pulse signal output command to the pulse signal supply device 50 (S501), and the signal input detection circuit. 80 outputs a high-level signal input detection signal (one pulse signal) to the delay signal generation circuit 81. As a result, the pulse signal supply device 50 outputs a pulse signal to the laser drive circuit 70, and the laser drive circuit 70 supplies the laser drive signal to the laser light source 31 in accordance with the input pulse signal. In this pulse signal, the low level period Lp is set to zero. In this way, at time t4, the processing object OB is irradiated with laser light having a processing intensity for one pulse. Therefore, the elapsed time from time t3 to time t4 corresponds to a delay time, that is, a timing deviation Dev.

  The controller 90 outputs a pulse signal output command to the pulse signal supply device 50 at time t5 when the X position before the second laser irradiation setting position (D + p) is detected. At this stage, the low level period Lp of the pulse signal has not yet been set. Therefore, the processing object OB is irradiated with the laser beam having the processing intensity for one pulse at the time t6 which is delayed by the timing deviation Dev from the time t5. Further, at time t5, the controller 90 determines “Yes” in step S624, and sets the low level period Lp of the pulse signal at the next processing setting position (laser irradiation setting position D + 2p). In step S504 and S505, the pulse signal is supplied from the controller 90 at time t7 when the X position that is equal to or greater than the third processing set position (D + 2p) by a predetermined distance (α + Dev · SP) is detected. A pulse signal output command is output to the device 50. In this case, the low level period Lp is a time obtained by dividing the difference between the position where the laser irradiation command is issued and the laser irradiation setting position by the moving speed SP (early time, and a, b, c in the figure). It is set to the time obtained by subtracting the timing deviation Dev from Thus, at time t8, the laser light source 31 emits laser light having an intensity corresponding to the pulse signal. Therefore, at time t9 when the low level period Lp has elapsed from time t8, laser light having a processing intensity is emitted from the laser light source 31. Thereby, a pit can be formed at the machining setting position. In the waveform (c) in the figure, the bold line portion represents the emission period of the pulse signal supplied from the pulse signal supply device 50.

  At time t7, the low level period Lp (= b−Dev) of the pulse signal at the next machining setting position (D + 3p) is also set by steps S626 to S630. Thus, when a pulse signal output command is output from the controller 90 to the pulse signal supply device 50 at time t10, laser light having an intensity corresponding to the pulse signal is emitted from the laser light source 31 at time t11. Therefore, at time t12 when the low level period Lp has elapsed from time 11, laser light having a processing intensity is emitted from the laser light source 31. At time t10, the low level period Lp (= c−Dev) of the pulse signal at the next machining setting position (D + 4p) is also set. Thus, when a pulse signal output command is output from the controller 90 to the pulse signal supply device 50 at time t13, laser light having an intensity corresponding to the pulse signal is emitted from the laser light source 31 at time t14. In this example, the low level period Lp is set to zero because the early departure time c and the timing shift Dev are the same. As a result, pits (machining traces) can be formed at the respective machining setting positions.

  Returning to the description of the timing adjustment routine of FIG. 13B. If the controller 90 determines in step S632 that the X position (D + s · p) is larger than the machining start position D ′, the process proceeds to step S636. In step S636, the controller 90 sets the value of the variable s to “1”, and in step S637, outputs information that sets the low level period Lp to zero to the pulse signal supply device 50. Subsequently, in steps S638 and S640, while the X position is input from the X direction position detection circuit 44, the process waits until the X position becomes equal to or higher than the hold switching position C ′. When it is detected that the X position is equal to or higher than the hold switching position C ′ (S640: Yes), the X position is input from the X-direction position detection circuit 44 in the subsequent steps S642 and S644, and the X position becomes the machining start position. It waits until it becomes below the position (D '+ (alpha)) which added detection unit distance alpha to D'. At the time of this standby, simultaneously with the confirmation of the X position, it is determined whether or not a laser irradiation stop command is output in step S646. That is, it is determined whether or not the command in step S163 in the laser processing control routine has been output.

  During this standby, the laser beam irradiation position moves in the X forward direction from the hold switching position C ′ to the stop position A ′, and then the movement direction is reversed at the stop position A. When the irradiation position of the laser beam in the X direction becomes equal to or less than the position (D ′ + α) that is a detection unit distance α before the processing start position D ′, the controller 90 performs a signal input detection circuit 80 in step S650. An operation start command is output.

  In the laser processing control routine described above, when the laser beam irradiation position moves in the negative X direction, the controller 90 outputs a pulse signal to the pulse signal supply device 50 at the timing when the processing start position D ′ is detected. A command is output (S511). Therefore, when the X position (D ′ + α) is detected in step S644, the pulse signal is not yet output from the pulse signal supply device 50 to the laser driving circuit 70. When the irradiation position of the laser beam further moves in the X negative direction by α, the X direction position detection circuit 44 outputs digital data representing the machining start position D ′ to the controller 90 and the signal input detection circuit 80. As a result, the signal input detection circuit 80 outputs a high-level signal input detection signal (one pulse signal) indicating that the signal has been input to the delay signal generation circuit 81. Further, the pulse signal supply device 50 outputs a pulse signal to the laser drive circuit 70 in response to a pulse signal output command from the controller 90. At this time, since the controller 90 outputs information that sets the low level period Lp of the pulse signal to zero to the pulse signal supply device 50 in step S637, the low level period Lp is zero. Therefore, the delay signal generation circuit 81 outputs a high-level signal only during the timing deviation Dev from the timing when the X direction position detection circuit 44 detects the machining start position D ′ to the timing when the intensity of the laser beam is switched to the machining intensity. To do.

  In step S652, the controller 90 inputs data from the A / D converter 82. In step S654, the controller 90 calculates a time when the signal generated by the delayed signal generation circuit 81 is at a high level as a timing shift Dev. To do. Subsequently, in Steps S656 and S658, the controller 90 waits until the X position becomes equal to or less than the position (D′−s · p + α + Dev · SP) while inputting the X position from the X direction position detection circuit 44. In this case, since s = 1 is set, it is determined that the position has reached a position that is a predetermined distance (α + Dev · SP) ahead of the point advanced by the machining pitch p in the negative X direction from the machining start position D ′. Will be. The position at which the X position is detected to be equal to or less than the position (D′−s · p + α + Dev · SP) is determined by the controller 90 when the second and subsequent pits are formed in step S515 of the laser processing control routine. This is a position where a pulse signal output command is issued to the supply device 50.

When controller 90 determines in step S658 that the X position has become equal to or less than the position (D′−s · p + α + Dev · SP), in subsequent step S660, it calculates an integer Nn according to the following equation.
Nn = INT {(position X−position (D ′ − (s + 1) · p + Dev · SP)) / α}
Subsequently, in step S662, the controller 90 calculates the low level period Lp by the following equation.
Lp = {(position (X−Nn · α) −position (D ′ − (s + 1) · p)) / SP} −Dev
Subsequently, in Step S664, the controller 90 sets the low level period Lp by outputting information indicating the calculated low level period Lp to the pulse signal supply device 50.

  The processing in steps S660 to S664 includes the position where the X position detection signal is output from the X direction position detection circuit 44 before the next machining setting position (D ′ − (s + 1) · p), and the machining setting position (D The time obtained by subtracting the timing deviation Dev from the time obtained by dividing the difference from '-(s + 1) · p) by the moving speed SP is set as the low level period Lp.

  Subsequently, in Step S666, the controller 90 determines whether or not the X position (D′−s · p) is smaller than the machining start position D. If the X position (D′−s · p) is greater than or equal to the machining start position D, the value of the variable s is incremented by “1” in step S668, and the process returns to step S656 and described above. Repeat the process. As a result, each time it is detected that the X position is equal to or greater than the position (D′−s · p + α + Dev · SP), the processing intensity laser is applied to the next machining setting position (D ′ − (s + 1) · p). A low level period Lp of a pulse signal for irradiating light is set. As a result, it is possible to irradiate laser light having a processing intensity at an appropriate timing, and it is possible to form pits (processing marks) at respective processing setting positions. If the controller 90 determines that the X position (D′−s · p) is smaller than the machining start position D in step S666, the controller 90 informs the pulse signal supply device 50 that the low level period Lp is zero in step S667. And the process returns to step S602 to repeat the same process.

  According to the second embodiment described above, the timing deviation Dev is detected each time the laser beam irradiation position passes through the machining start positions D and D ′ in the direction of entering the machining area, and based on the timing deviation Dev. Thus, the low level period Lp of the pulse signal for irradiating the laser beam with the processing intensity is set for each processing setting position. For this reason, pits can be accurately formed at each processing set position, and the positions of the pits in the pit row adjacent in the Y direction can be aligned. Further, the machining setting position in the X direction can be set to a position different from the position where the X direction position detection circuit 44 outputs the X position detection signal. That is, the low level period Lp is divided by the moving speed SP by the difference between the position where the laser irradiation command is issued (the position where the X direction position detection circuit 44 outputs the X position detection signal) and the laser irradiation setting position (processing setting position). Since the low level period Lp is calculated by subtracting the timing deviation Dev from the early pick-up time obtained (a, b, c in FIG. 14), the machining setting position in the X direction can be arbitrarily set. Accordingly, the degree of freedom of pit arrangement increases. Further, a machining setting position in the X direction is determined from the machining start positions D and D ′ and the machining pitch p, and the irradiation position of the laser beam is reciprocated in the X direction, and the feed movement is performed in the Y direction at both ends of the reciprocating movement. Therefore, by making the feed amount in one direction in the Y direction equal to the processing pitch p, it is possible to form nano-order fine pits arranged in a square shape. Further, by shifting the machining setting positions in the X direction in the adjacent pit rows by a half machining pitch, the pits can be arranged in a hexagonal close-packed manner. As a result, high-quality LED substrates and liquid crystal substrates can be manufactured.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the object of the present invention.

  For example, in this embodiment, the timing deviation Dev is detected for each movement in the reciprocating movement in the X direction. However, the fluctuation of the timing deviation Dev is very small during the laser machining period, and the machining setting position and the laser machining are detected. If the deviation from the position is within an allowable range, the timing deviation Dev detected first may be continuously used during laser processing. If the timing deviation Dev hardly fluctuates over a long period of time, the detected timing deviation Dev is stored in a storage means such as a nonvolatile memory, and the timing deviation Dev is read when laser processing is started. You may make it use over.

  In this embodiment, the pits are formed in a square arrangement, but may be formed in a hexagonal close arrangement, for example. Moreover, it is not restricted to such an arrangement.

  In this embodiment, the laser light irradiation position is reciprocated in the X direction, and the feed movement is performed in the Y direction at both ends of the reciprocation in the X direction. However, the movement route of the laser light irradiation position is not limited to this. It can be set arbitrarily. In this embodiment, the laser light irradiation position is moved by moving the stage 21. However, the processing head 30 may be moved in the X and Y directions, or the stage 21 and the processing head. The structure which moves both 30 in relation may be sufficient.

  The laser processing is not limited to forming the pits by irradiating the surface of the processing object OB with the processing laser light, but irradiating the processing object OB having the surface coated with the photoresist with the processing laser light. A reaction trace may be formed on the photoresist, and thereafter the reaction trace may be removed with a developer, and pits may be formed on the workpiece OB by etching using the remaining photoresist as a mask.

  The moving means in the present embodiment includes the X-direction feed motor 22 and the Y-direction feed motor 23 corresponding to the moving means of the present invention, and the encoders 22a and 23a, the X-direction position detection circuit 44, and the Y-direction position in the present embodiment. The detection circuit 45 corresponds to the movement position detection means in the present invention. Further, the pulse signal supply device 50 and the laser drive circuit 70 in the present embodiment correspond to the light emission signal supply means of the present invention, and the X-direction feed motor control circuit 42, the Y-direction feed motor control circuit 43 in the present embodiment, and The process in which the controller 90 commands the movement position in the laser processing control routine corresponds to the movement control means of the present invention. In addition, the process in which the controller 90 in the present embodiment issues a laser beam irradiation command of the processing intensity and the non-processing intensity based on the X position in the laser processing control routine corresponds to the laser light irradiation control means of the present invention.

  In addition, a process (S308 to S318, S328 to S338, S321-3 to S321-6, S343 to S346, S610 to S620, S644 to S654) in which the controller 90 in the present embodiment calculates the timing deviation Dev in the timing adjustment routine. This corresponds to the timing shift detection means and the timing shift detection step of the present invention. Further, the process (S320, S340, S321-7, S347, S630, S664) in which the controller 90 in the present embodiment sets the time width or low level period of the low level signal in the timing adjustment routine is the light emission signal supply timing of the present invention. This corresponds to the adjusting means and the light emission signal supply timing adjusting step. In addition, the process (S321-3 to S321-6, S343 to S346) in which the controller 90 according to the present embodiment repeatedly calculates the timing deviation after the machining is started in the timing adjustment routine is the midway timing deviation detecting means and midway timing deviation detection in the present invention. It corresponds to a step. Further, the process (S321-7, S347) in which the controller 90 in the present embodiment repeatedly sets the time width of the low level signal after the start of machining in the timing adjustment routine is the midway light signal supply timing adjustment means, the midway light signal supply in the present invention. This corresponds to the timing adjustment step.

  Further, the process in which the controller 90 in the present embodiment detects the X position and the Y position in the laser processing control routine corresponds to the moving position detection step of the present invention, and the controller 90 in the present embodiment has the X position and the position in the laser processing control routine. The process of moving the laser light irradiation position based on the Y position corresponds to the movement control step of the present invention. Moreover, the process in which the controller 90 in this embodiment issues a laser beam irradiation command of the processing intensity and the non-processing intensity based on the X position in the laser processing control routine corresponds to the light emission command step of the present invention. In addition, the process in which the pulse signal supply device 50 and the laser drive circuit 70 in the present embodiment supply the light emission signal to the laser light source in accordance with the light emission command corresponds to the light emission signal supply step.

  DESCRIPTION OF SYMBOLS 1 ... Laser processing apparatus, 20 ... Stage drive device, 21 ... Stage, 22 ... X direction feed motor, 22a, 23a ... Encoder, 23 ... Y direction feed motor, 30 ... Processing head, 31 ... Laser light source, 35 ... Objective lens , 42 ... X direction feed motor control circuit, 43 ... Y direction feed motor control circuit, 44 ... X direction position detection circuit, 45 ... Y direction position detection circuit, 50 ... Pulse signal supply device, 50a ... Memory, 61 ... HF signal Amplifying circuit, 70 ... laser driving circuit, 80 ... signal input detection circuit, 81 ... delayed signal generating circuit, 82 ... A / D converter, 90 ... controller, 90a ... memory, OB ... working object.

Claims (10)

A stage for setting the workpiece,
A processing head that has a laser light source, and condenses and irradiates the laser beam emitted from the laser light source onto an object to be processed set on the stage;
Moving means for moving the irradiation position of the laser beam on the object to be processed in the X direction and the Y direction orthogonal to the X direction by changing the relative position between the processing head and the stage;
A moving position detecting means for detecting a relative X direction position and a Y direction position of the processing head and the stage, which are changed by the moving means;
A light emission signal supply means for supplying a light emission signal for emitting laser light having a set intensity with respect to the laser light source;
Based on the relative position between the processing head and the stage detected by the moving position detecting means, the moving means is moved so that the irradiation position of the laser beam on the processing object moves along a preset moving route. Movement control means for controlling;
When the moving means is controlled by the movement control means, the processing setting position is irradiated with laser light having a processing intensity based on the irradiation position of the laser light detected by the moving position detecting means, and the processing setting is set. A laser beam irradiation control unit that outputs a command to supply the light emission signal to the light emission signal supply unit so that a laser beam having a non-processing intensity is irradiated to a position different from the position. ,
The set position when the light emission signal supply command for outputting the laser beam having the processing intensity is output to the light emission signal supply means at the timing when the moving position detection means detects a preset setting position. A timing shift detection means for detecting a timing shift from the detected timing to the timing at which the laser beam of the processing intensity is emitted from the laser light source;
Based on the detected timing deviation, a light emission signal for emitting the laser beam with the processing intensity by changing the time width of the light emission signal with which the light emission signal supply unit emits the laser beam with the non-processing intensity. A laser processing apparatus comprising: a light emission signal supply timing adjusting unit that adjusts a timing at which the laser is supplied to the laser light source. The light emission signal supply means is a pulse train signal in which a high level signal for emitting laser light of processing intensity to the laser light source and a low level signal for emitting laser light of non-processing intensity are alternately switched at a constant cycle. Is output,
The movement control means controls the movement means so that the irradiation position of the laser beam moves at a constant speed along the movement route when the light emission signal supply means outputs the pulse train signal,
The laser light irradiation control means outputs a supply command for supplying the pulse train signal to the laser light source to the light emission signal supply means when the processing start setting position is detected,
The light emission signal supply timing adjustment means shortens the time width of one low-level signal in the pulse train signal by a time corresponding to the timing deviation when the timing deviation is detected by the timing deviation detection means. The laser processing apparatus according to claim 1, wherein: The movement control means reciprocates the irradiation position of the laser beam between the first stop position and the second stop position in the X direction, and feeds and moves in the Y direction between the first stop position and the second stop position. It is what
The laser light irradiation control means detects that the laser light irradiation position has reached a processing start position that is the start of a processing setting range set between the first stop position and the second stop position. And a supply command for supplying the pulse train signal to the laser light source to the light emission signal supply means,
The timing shift detection means is configured to detect the timing of detecting that the laser light irradiation position has reached the processing start position every time it is detected that the laser light irradiation position has reached the processing start position. Detects timing deviations until the laser light of processing intensity is emitted from the laser light source,
The light emission signal supply timing adjustment means shortens the time width of one low-level signal in the pulse train signal by a time corresponding to the timing deviation each time the timing deviation is detected by the timing deviation detection means. The laser processing apparatus according to claim 2. Whenever it is detected that the irradiation position of the laser beam has reached a specific processing setting position set in the middle of the processing setting range, it is detected that the irradiation position of the laser beam has reached the specific processing setting position A timing deviation detection means for detecting a timing deviation from a timing to a timing at which a laser beam of processing intensity is emitted from the laser light source;
By changing the time width of one low level signal in the pulse train signal based on the timing deviation detected by the midway timing deviation detection means, a light emission signal for emitting laser light having the processing intensity is emitted from the laser. The laser processing apparatus according to claim 3, further comprising: a halfway light emission signal supply timing adjusting unit that adjusts a timing supplied to the light source. The light emission signal supply means emits a laser beam having a non-machining intensity immediately before outputting a high level signal for outputting a high level signal for emitting a laser beam having a processing intensity to the laser light source. A low-level signal that outputs a low-level signal to output a low-level DC signal that emits a laser beam with non-processing intensity when the pulse signal is not output,
The laser light irradiation control means outputs a supply command of the pulse signal to the light emission signal supply means each time a light emission command position set at a position before the processing setting position is detected,
The light emission signal supply timing adjustment means detects the timing deviation detected by the timing deviation detection means from the time required for the laser light irradiation position to move the distance between the processing setting position and the light emission command position. The laser processing apparatus according to claim 1, wherein a time obtained by subtracting the time is set as a low level period of the pulse signal. The relative position between the stage for setting the processing object and the processing head that has a laser light source and condenses the laser beam by the objective lens and irradiates the processing object is perpendicular to the X direction and the X direction. A moving position detecting step for detecting by direction;
Based on the relative position between the stage and the processing head detected by the moving position detection step, the stage is arranged so that the irradiation position of the laser beam on the processing object moves along a preset moving route. And a movement control step for changing a relative position between the machining head and the machining head;
Based on the irradiation position of the laser beam detected by the movement position detection step when the irradiation position of the laser beam on the object to be processed is moving along a preset movement route by the movement control step. A light emission command step for outputting a light emission signal supply command so that the processing setting position is irradiated with the processing intensity laser beam and the non-processing intensity laser light is irradiated at a position different from the processing setting position;
A light emission signal supply step of supplying a light emission signal for emitting a laser beam having a set intensity to a laser light source in accordance with a light emission signal supply command output in the light emission command step;
The laser is detected from the timing at which the set position is detected when a light emission signal supply command for emitting the laser beam having the processing intensity is output at the timing at which a preset set position is detected by the moving position detecting step. A timing shift detection step for detecting a timing shift from the light source to the timing at which the processing intensity laser beam is emitted;
Based on the detected timing deviation, a light emission signal for emitting the processing intensity laser light is transmitted to the laser light source by changing a time width of the emission signal for emitting the non-processing intensity laser light. And a light emission signal supply timing adjustment step of adjusting a supply timing. The light emission signal supplying step includes a pulse train signal in which a high level signal for emitting laser light with processing intensity to the laser light source and a low level signal for emitting laser light with non-processing intensity are alternately switched at a constant cycle. Is output,
In the movement control step, when the pulse train signal is output in the light emission signal supply step, the irradiation position of the laser beam is controlled to move along the movement route at a constant speed,
The light emission command step outputs a supply command for supplying the pulse train signal to the laser light source when the processing start setting position is detected,
In the light emission signal supply timing adjustment step, when the timing shift is detected by the timing shift detection step, the time width of one low-level signal in the pulse train signal is shortened by a time corresponding to the timing shift. The laser processing method according to claim 6. In the movement control step, the irradiation position of the laser beam is reciprocated between the first stop position and the second stop position in the X direction, and the feed position is moved in the Y direction between the first stop position and the second stop position. It is what
The light emission command step is performed every time when it is detected that the irradiation position of the laser beam has reached the processing start position that is the start of the processing setting range set between the first stop position and the second stop position. A supply command for supplying the pulse train signal to the laser light source;
The timing deviation detection step is performed from the timing at which it is detected that the laser light irradiation position has reached the processing start position every time it is detected that the laser light irradiation position has reached the processing start position. Detects timing deviations until the laser light of processing intensity is emitted from the laser light source,
The light emission signal supply timing adjustment step shortens the time width of one low-level signal in the pulse train signal by a time corresponding to the timing deviation every time the timing deviation is detected by the timing deviation detection step. The laser processing method according to claim 7. Whenever it is detected that the irradiation position of the laser beam has reached a specific processing setting position set in the middle of the processing setting range, it is detected that the irradiation position of the laser beam has reached the specific processing setting position A timing deviation detection step for detecting a timing deviation from the timing to the timing at which the laser light of processing intensity is emitted from the laser light source;
Based on the timing deviation detected in the midway timing deviation detection step, by changing the time width of one low-level signal in the pulse train signal, a light emission signal for emitting laser light having the processing intensity is emitted from the laser. The laser processing method according to claim 8, further comprising: an intermediate light emission signal supply timing adjustment step of adjusting a timing supplied to the light source. In the light emission signal supplying step, a laser beam having a non-machining intensity is emitted immediately before outputting a high level signal for outputting a high level signal for emitting a laser beam having a machining intensity to the laser light source. A low-level signal that outputs a low-level signal to output a low-level DC signal that emits a laser beam with non-processing intensity when the pulse signal is not output,
The light emission command step outputs a supply command of the pulse signal every time a light emission command position set at a position before the processing setting position is detected,
In the light emission signal supply timing adjustment step, the timing deviation detected by the timing deviation detection step is determined from the time required for the laser light irradiation position to move the distance between the processing setting position and the light emission command position. The laser processing method according to claim 6, wherein a time obtained by subtracting the time is set as a low level period of the pulse signal.

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