JP6301198B2 - Laser processing apparatus and laser processing method - Google Patents

Description

  The present invention relates to a laser processing apparatus and a laser processing method for performing groove processing or the like on a workpiece such as a substrate using a laser beam.

  Conventionally, there has been known a laser processing apparatus configured to irradiate a substrate with a pulsed laser beam and move the substrate in a direction perpendicular to the optical axis of the laser beam to perform groove processing.

  In such a laser processing apparatus, when the substrate is moved along the processing line, acceleration occurs at the start of processing and deceleration occurs at the end of processing. Further, since the moving direction changes greatly in a bent portion obtained by bending a straight line or a curved portion having a large curvature, it is necessary to decelerate compared to a straight portion or a curved portion having a small curvature.

  However, in these acceleration / deceleration regions, there is a problem that the pitch of the laser pulse is not constant, the heat due to the laser pulse is excessive, the width and depth of the groove are not uniform, and the processing quality is deteriorated.

  In order to solve such a problem, for example, as disclosed in Patent Documents 1, 2, 3, and 4, the moving speed of the workpiece is detected, and the laser pulse is detected according to the detected moving speed. Some control output timing.

Japanese Patent No. 3854822 JP 2003-53563 A JP 2010-184289 A JP 2012-130959 A

However, both of these conventional techniques change the frequency of the laser oscillator in the acceleration / deceleration region, so that energy fluctuation occurs in the laser oscillator and the beam diameter changes, and the groove width and groove depth are reduced. There was a drawback that the processing quality still deteriorated, such as changing.
Furthermore, some non-worked products have different processing characteristics in the vertical direction and the horizontal direction, and there is a drawback that the groove width and the groove depth vary depending on the processing direction.

  On the other hand, in order to reduce energy fluctuation, a method of continuously outputting a laser at a certain energy level and extracting a laser pulse from the laser can be considered, but with this method, a high-energy laser pulse is emitted. It is difficult to obtain, the necessary processing on the workpiece cannot be performed, and there is a disadvantage that a large-capacity laser oscillator must be provided.

  Therefore, the present invention has a groove width and a groove depth that are not provided with a large-capacity laser oscillator, even in the acceleration / deceleration region of laser processing, and in the case of non-workpieces having different vertical and horizontal processing characteristics. An object of the present invention is to provide a laser processing apparatus and a laser processing method that can eliminate defects such as changes and improve processing quality.

  In order to solve the above-described problem, in the laser processing apparatus according to claim 1, a laser pulse oscillation unit that oscillates a laser pulse train having a constant period, a laser pulse train output from the laser pulse oscillation unit, and the laser pulse train An optical directing unit capable of selectively directing a laser pulse in a direction used for processing, an optical system for receiving the laser pulse from the light directing unit and irradiating the workpiece, and the workpiece A table driving unit that drives the table placed in the X-axis direction and the Y-axis direction, a movement amount detection unit that detects the movement amounts of the table in the X-axis direction and the Y-axis direction, and the movement amount detection unit A correction unit that corrects the movement amounts in the X-axis direction and the Y-axis direction, a predetermined movement amount detection unit that detects that the movement amount corrected by the correction unit has reached a predetermined amount, and the predetermined movement And a control unit that controls the light directing unit to direct a laser pulse in the laser pulse train output from the laser pulse oscillating unit in the processing direction when the detection unit detects a predetermined movement amount. And

  The laser processing apparatus according to claim 2 is characterized in that, in the laser processing apparatus according to claim 1, the correction amount in the correction unit is selected based on processing characteristics of the workpiece.

  Further, in the laser processing method according to claim 3, in the laser processing method for processing a workpiece by irradiating the workpiece with a laser beam, a laser pulse train having a constant period is oscillated, and the workpiece is placed. Detecting the movement amounts of the table in the X-axis direction and the Y-axis direction, correcting the detected movement amounts in the X-axis direction and the Y-axis direction, and confirming that the corrected movement amount has reached a predetermined amount. When detected, the laser pulse in the laser pulse train is selectively directed in a direction used for processing.

  The laser processing method according to claim 4 is characterized in that in the laser processing method according to claim 3, the amount of the correction is selected based on processing characteristics of the workpiece.

  According to the present invention, even if a large-capacity laser oscillator is not provided, the groove width and groove depth can be reduced even in the acceleration / deceleration region of laser processing, and even in the case of a non-workpiece having different vertical and horizontal processing characteristics. It is possible to obtain a laser processing apparatus and a laser processing method that can eliminate defects such as changes and improve processing quality.

It is a block diagram of the laser processing apparatus which becomes one Example of this invention. FIG. 2 is a timing chart of signals and the like in each unit of the laser processing apparatus shown in FIG. It is a figure which shows the structure of the predetermined movement amount detection part in FIG. It is a figure which shows the structure of the AOM control part in FIG. It is a figure for demonstrating the effect of this invention.

  An embodiment of the present invention will be described. FIG. 1 is a block diagram of a laser processing apparatus according to an embodiment of the present invention, and FIG. 2 is a timing chart of signals and the like in each part of the laser processing apparatus shown in FIG.

  In FIG. 1, reference numeral 1 denotes a laser oscillator that generates a laser pulse L1, and reference numeral 2 denotes a laser oscillation control unit that outputs a laser oscillation command signal S1 having a constant period to the laser oscillator 1. The laser oscillator 1 outputs a laser pulse L1 only when a laser oscillation command signal S1 is given from the laser oscillation control unit 2, and a laser pulse oscillation unit 3 that generates a laser pulse train having a constant period by both of them is provided. Composed. The laser oscillator 1 has a characteristic that the laser pulse L1 at the rise and fall of the laser oscillation command signal S1 changes in a curve. 4 is an acousto-optic modulator (hereinafter abbreviated as AOM) that can selectively control the branch direction of the laser pulse L1 output from the laser oscillator 1 for each laser pulse L1, and 5 is an AOM control signal to the AOM 4. An AOM control unit 6 outputs S2 and controls its operation, and 6 is an optical system that irradiates the workpiece with a laser pulse L2 branched from the AOM4.

  When the AOM control signal S2 is given, the AOM 4 branches the laser pulse L1 from the laser oscillator 1 to the optical system 6 in the processing direction (ON state), while when the AOM control signal S2 is not given, the laser oscillator The laser pulse L1 from 1 is branched in the direction of a damper (not shown) so as not to go to the optical system 6 (OFF state).

  7 is a workpiece such as a substrate, 8 is a table on which the workpiece 7 is placed, 9 is a table drive unit that drives the table 8 in the X direction and Y direction, and 10 is a table 8 that moves the table 8 in the X direction by a predetermined amount. An X-axis scale for outputting a pulse every time the operation is performed, and a Y-axis scale 11 for outputting a pulse each time the table 8 moves by a predetermined amount in the Y direction. A predetermined movement amount detection unit 12 periodically detects a predetermined amount of movement of the table 8 and outputs a predetermined movement amount detection signal S3 to the AOM control unit 5 for every predetermined amount of movement.

  FIG. 3 is a diagram illustrating a configuration of the predetermined movement amount detection unit 12. The predetermined movement amount detection unit 12 includes an X-axis movement direction detection circuit 13 that detects a movement direction by a pulse from the X-axis scale 10, a Y-axis movement direction detection circuit 14 that detects a movement direction by a pulse from the Y-axis scale 11, It includes counters 15 to 18 for counting the positive and negative pulses on the X axis and the positive and negative pulses on the Y axis, respectively.

  The predetermined movement amount detection unit 12 further includes an X-axis correction circuit 31 that corrects the count values of the counters 15 and 16 on the X-axis side, and a Y-axis correction circuit 32 that corrects the count values of the counters 17 and 18 on the Y-axis side. including. An overall control unit 30 controls the entire apparatus using a microcomputer, and sets a correction multiple input by an operator in the X-axis correction circuit 31 and the Y-axis correction circuit 32. The X-axis correction circuit 31 and the Y-axis correction circuit 32 correct and output the count values of the counters 15 to 18 based on the set correction multiple.

The correction multiple is as follows.
In the case of a non-workpiece having the same machining characteristics in the vertical and horizontal directions, the overall control unit 30 does not operate the X-axis correction circuit 31 and the Y-axis correction circuit 32 and the counters 15 to 18 are not corrected. In the case of a non-workpiece having machining characteristics such that the required groove width and depth cannot be obtained unless one machining direction is compared with the other machining direction and the machining pitch is shortened, the operator can Enter the correction multiple for one machining direction. In this case, the correction multiple is set to a value larger than one. The overall control unit 30 sets the correction multiple in the correction circuit in the corresponding direction so that the count value of the counter in the corresponding direction is updated earlier than usual. Here, how much larger than 1 is set as the correction multiple is determined in advance by the machining characteristics of the non-workpiece, and the corresponding one is selected by the operator and input to the overall control unit 30.

  The predetermined movement amount detection unit 12 further includes a combined count amount calculation circuit 19 that obtains a combined count amount Z of the X axis and the Y axis based on the count values output from the counters 15 to 18 by the following formula, and the combined count amount Z Is a predetermined value, for example, 5 in this embodiment, and when this value is reached, a specific value detection circuit 20 that outputs a predetermined movement amount detection signal S3 is included.

(Equation 1)
Z = ((Xup−Xdn) ² + (Yup−Ydn) ² ) ^1/2

  Here, Xup is the value of the counter 15, Xdn is the value of the counter 16, Yup is the value of the counter 17, and Ydn is the value of the counter 18.

  The AOM control unit 5 is supplied with a laser oscillation command signal S1 with a fixed period from the laser oscillation control unit 2, and when the predetermined movement amount detection signal S3 is output from the predetermined movement amount detection unit 12, An AOM control signal S2 for branching the laser pulse L1 from the laser oscillator 1 to the optical system 6 (ON state) is output to the AOM 4.

  FIG. 4 is a diagram showing the configuration of the AOM control unit 5. When the laser oscillation command signal S1 is input from the laser oscillation control unit 2, the laser oscillation command signal S1 is delayed by the delay circuit 21 by time t, and the AND circuit 22 detects the predetermined movement amount from the predetermined movement amount detection unit 12. ANDed with the signal S3.

  The output signal of the AND circuit 22 triggers the one-shot circuit 23 that generates a pulse for a predetermined time, and the output signal becomes the AOM control signal S2. The falling edge of the output signal of the one-shot circuit 23 is detected by the falling edge detection circuit 24 and becomes a control signal S4 to the predetermined movement amount detection unit 12 to reset the count values of the counters 15-18. When the count values of the counters 15 to 18 are reset, the composite count amount Z in the composite count amount calculation circuit 19 becomes zero.

  Here, the pulse width TA of the one-shot circuit 23 is set to satisfy TB ≧ t + TA, where TB is the pulse width of the laser oscillation command signal S1. When the laser pulse is oscillated at a certain period, the transition period at the rising and falling parts is not always stable at each period, so if it is set as described above, the output from the AOM 4 The laser pulse L2 is a laser pulse L1 output from the laser oscillator 1 from which the rising and falling portions, which are unstable regions, are removed, and the processing quality can be improved.

  According to the above-described embodiment, a laser pulse having a constant period in which energy fluctuation is unlikely to occur is selectively given to the workpiece 7 for each predetermined movement amount of the table 8 via the AOM 4, and therefore, as shown in FIG. Thus, even in the acceleration / deceleration region of laser processing, the groove width and groove depth are not changed, and the processing quality can be improved.

  Furthermore, according to the above embodiment, in the case of a non-workpiece having machining characteristics such that the groove width and groove depth in the X-axis direction are smaller than those in the Y-axis direction, the operator sets the correction multiple in the X-axis direction as a whole. Input to the control unit 30. As a result, the update speed of the counters 15 and 16 on the X-axis side becomes faster than usual, and the pitch of the laser pulses irradiated to the non-workpiece is shortened, and the groove width and groove depth in the X-axis direction are set in the Y-axis direction. It is possible to improve the processing quality.

  In the above embodiment, the count value of either the X-axis counter or the Y-axis counter is corrected. However, the count values of both counters may be corrected. For example, when the processing characteristics in the vertical direction and the horizontal direction are greatly different, it is possible to make the groove width and the groove depth in both directions easy by making one larger than 1 time and the other smaller than 1 time. .

  In the above embodiment, the laser pulse L1 output from the laser oscillator 1 is branched by the AOM. However, the present invention is not limited to this, and other means can be used as long as the direction of the laser pulse can be controlled by an electrical signal. It may be used.

  In addition, in the above embodiment, the predetermined movement amount detection unit 12 includes several circuits and the like, but those skilled in the art will understand that these circuits and the like may be realized in software using a microcomputer. It is obvious.

1: laser oscillator, 2: laser oscillation control unit, 3: laser pulse oscillation unit,
4: Acousto-optic modulator (AOM), 5: AOM control unit, 6: optical system, 7: substrate
8: Table, 9: Table drive unit, 10: X axis scale, 11: Y axis scale,
12: predetermined movement amount detection unit, 13: X axis movement direction detection circuit,
14: Y-axis movement direction detection circuit, 15-18: Counter,
19: composite count amount calculation circuit, 20: specific value detection circuit, 21: delay circuit,
22: AND circuit, 23: one-shot circuit, 24: falling detection circuit,
30: Overall control unit, 31: X-axis correction circuit, 32: Y-axis correction circuit,
S1: Laser transmission command signal, S2: AOM control signal, S3: Predetermined movement amount detection signal,
S4: Control signal, L1, L2: Laser pulse

Claims (4)

  A laser pulse oscillating unit that oscillates a laser pulse train of a fixed period, and light that can receive the laser pulse train output from the laser pulse oscillating unit and selectively direct the laser pulses in the laser pulse train to a direction used for processing. A directing unit, an optical system that receives a laser pulse from the light directing unit and irradiates the workpiece, and a table driving unit that drives a table on which the workpiece is placed in the X-axis direction and the Y-axis direction. A movement amount detection unit that detects movement amounts of the table in the X-axis direction and the Y-axis direction, a correction unit that corrects movement amounts in the X-axis direction and the Y-axis direction detected by the movement amount detection unit, A predetermined movement amount detection unit that detects that the movement amount corrected by the correction unit has reached a predetermined amount; and when the predetermined movement amount detection unit detects a predetermined movement amount, the laser pulse is transmitted to the light directing unit. Laser processing apparatus, characterized in that it comprises a control unit for controlling the laser pulse in the laser pulse train outputted from the oscillating unit to direct to the working direction.   The laser processing apparatus according to claim 1, wherein the correction amount in the correction unit is selected based on a processing characteristic of the workpiece.   In a laser processing method for processing a workpiece by irradiating the workpiece with a laser beam, a laser pulse train having a constant period is oscillated, and the table on which the workpiece is placed moves in the X-axis direction and the Y-axis direction. Detecting the amount of movement, correcting the detected movement amount in the X-axis direction and the Y-axis direction, and selectively detecting the laser pulse in the laser pulse train when detecting that the corrected movement amount has reached a predetermined amount. A laser processing method characterized by directing in a direction used for processing. 4. The laser processing method according to claim 3, wherein the correction amount is selected based on a processing characteristic of the workpiece.

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