JP7051653B2 - Laser processing equipment, laser processing method, program for the method, and recording medium on which the program is recorded. - Google Patents

Description

The present invention relates to, for example, a laser processing apparatus for drilling holes in a printed circuit board using a laser, a laser processing method, a program for the method, and a recording medium on which the program is recorded.

Conventionally, in a laser processing device using a laser oscillator such as a carbon dioxide laser oscillator, a laser pulse is oscillated by the laser oscillator in synchronization with the completion of the positioning operation by the galvano scanner for changing the laser irradiation position, and diffraction by ultrasonic waves is performed. A laser deflection unit using an acoustic optical element (hereinafter abbreviated as AOM) using a crystal body such as germanium that generates a grating deflects the laser pulse output from the laser oscillator from the non-machining direction to the machining direction. Things are known.

When germanium is used as the crystal body of the AOM, heat is generated by light absorption when the laser pulse passes through the inside of the crystal, and the laser pulse acts as a lens (thermal lens action). This fluctuation in the action of the thermal lens causes deterioration of processing quality.

Patent Document 1 controls the pulse width of a laser pulse oscillated from a laser oscillator in laser processing that controls the laser output of the laser oscillator to saturate and reach a peak value according to the completion time of the positioning operation of the galvano scanner. A technique is disclosed in which the energy received by the AOM is made substantially constant by controlling the number of dummy pulses or the number of dummy pulses, and the adverse effect of the AOM's thermal lens action is suppressed.
However, Patent Document 1 does not disclose how to determine the pulse width of the laser pulse and the number of dummy pulses, and the specific means for realizing the laser pulse is unknown. Therefore, in reality, it is not possible to suppress the adverse effect of the fluctuation of the thermal lens action of AOM.

On the other hand, Patent Document 2 describes the pulse width according to the length of the drive period during the drive period of the galvano scanner as a technique for controlling the pulse width and the number of pulses of the laser pulse oscillated from the laser oscillator as in Patent Document 1. And the one that oscillates a dummy pulse to a laser oscillator at a repetition frequency is disclosed.
However, the technique of Patent Document 2 is for stabilizing the output energy of the laser oscillator, and does not consider the thermal lens action of AOM. According to paragraph 0046 of Patent Document 2, since the pulse width and repetition frequency of the dummy pulse change each time the galvano scanner is driven, the energy received by the AOM constantly fluctuates, and the processing quality deteriorates due to the fluctuation of the thermal lens action. There is.

Japanese Patent No. 4492041 Japanese Patent No. 5197271

Therefore, according to the present invention, in the laser processing in which the laser pulse is oscillated in the laser oscillator in synchronization with the completion of the positioning operation by the optical scanner for changing the laser irradiation position, the laser pulse from the laser oscillator is transmitted to the optical scanner. The purpose is to suppress adverse effects due to fluctuations in the thermal lens action of the optical element in the incident path.

In order to solve the above problems, the typical laser processing apparatus disclosed in the present application is a laser oscillator that oscillates a laser pulse and an optical scanner in which the laser pulse is incident via an optical element, and is used for processing data. It is a laser oscillation control unit that controls the oscillation of the laser pulse by the laser oscillator and the one that drives the workpiece to irradiate the machining position on the workpiece, which is synchronized with the completion of the positioning operation in the optical scanner. In a laser processing apparatus provided with a device for oscillating a laser pulse for processing, the optical scanner is based on the time point at which the laser pulse for processing is oscillated each time the optical scanner is newly driven. The laser oscillation control unit has a positioning completion prediction unit that predicts the time point at which the positioning operation is completed, and the time T from the oscillation time point to the positioning operation completion prediction time point is n × T0>T> (n−). 1) In the case of × T0 (T0 is a predetermined time, n is an integer of 2 or more), the first laser pulse having the same pulse width as the processing laser pulse is performed n-2 times in succession, than the processing laser pulse. A second laser pulse having a short pulse width is oscillated once by the laser oscillator as a dummy pulse each time the predetermined time T0 elapses in the time from the oscillation time point to the positioning operation completion prediction time point. The laser pulse is characterized by having a pulse width for adjusting the duty until the subsequent processing laser pulse is oscillated.

Further, a typical laser processing method disclosed in the present application is an optical scanner that drives a laser pulse oscillated by a laser oscillator to irradiate a processing position on a workpiece according to processing data via an optical element. In a laser processing method in which a laser pulse for processing is oscillated by the laser oscillator in synchronization with the completion of the positioning operation in the optical scanner, the optical scanner is newly driven each time. The time point at which the positioning operation in the optical scanner is completed is predicted based on the oscillation time point of the laser pulse for processing, and the time T from the oscillation time point to the positioning operation completion prediction time point is n × T0>T> (. In the case of n-1) × T0 (T0 is a predetermined time, n is an integer of 2 or more), the first laser pulse having the same pulse width as the processing laser pulse is repeatedly performed n-2 times, and then the processing laser. A second laser pulse having a pulse width shorter than that of the pulse is oscillated once in the laser oscillator as a dummy pulse each time the predetermined time T0 elapses in the time from the oscillation time to the positioning operation completion prediction time. The second laser pulse is characterized by having a pulse width for adjusting the duty until the subsequent processing laser pulse is oscillated.

The typical features of the invention disclosed in the present application are as described above, but the features not described here are applied to the examples described below, and are also included in the claims. As shown.

According to the present invention, in laser processing in which a laser oscillator is made to oscillate a laser pulse in synchronization with the completion of a positioning operation by an optical scanner for changing a laser irradiation position, the laser pulse from the laser oscillator is optically scanned. It is possible to suppress the adverse effect of the thermal lens action on the optical element in the path incident on the vessel.

It is a timing chart for demonstrating the state of the oscillation of the laser pulse in the laser drilling apparatus which becomes Example 1 of this invention. It is a control flowchart of the laser oscillation control unit in the laser drilling apparatus which becomes Example 1 of this invention. It is a control flowchart of the laser oscillation control unit in the laser drilling apparatus which becomes Example 1 of this invention. It is a control flowchart of the laser oscillation control unit in the laser drilling apparatus which becomes Example 1 of this invention. It is a block diagram of the laser drilling apparatus which becomes Example 1 of this invention. It is a timing chart when the laser pulse for processing is oscillated from the laser oscillator in the laser drilling apparatus which becomes Example 1 of this invention. It is a block diagram of the laser drilling apparatus which becomes Example 2 of this invention. It is a timing chart for demonstrating the state of the oscillation of the laser pulse in the laser drilling apparatus which becomes Example 2 of this invention. It is a block diagram of the laser drilling apparatus which becomes Example 3 of this invention. It is a timing chart for demonstrating the state of the oscillation of the laser pulse in the laser drilling apparatus which becomes Example 3 of this invention. It is a timing chart for demonstrating the state of the oscillation of the laser pulse in the laser drilling apparatus which becomes Example 3 of this invention. It is a timing chart when the laser pulse for processing is oscillated from the laser oscillator in the laser drilling apparatus which becomes another embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Example 1
FIG. 5 is a block diagram of a laser drilling device according to a first embodiment of the present invention. Each component and connecting line mainly shows what is considered necessary for explaining this embodiment, and does not show all necessary for a laser drilling device. The same applies to the block diagram of the laser drilling device that appears below.
In FIG. 5, 1 is a printed substrate placed on a table (not shown) to be processed, 2 is a laser oscillator that oscillates a laser pulse L1, and 3 is a laser pulse L1 output from the laser oscillator 2 that is processed by using AOM. The laser deflection unit 4 for deflecting in the direction changes the laser irradiation position of the laser pulse L2 deflected in the processing direction in the laser deflection unit 3, and is rotationally driven so as to irradiate the drilling position of the printed substrate 1 according to the processing data. It is a galvano scanner as an optical scanner. Reference numeral 5 is a damper that absorbs the laser pulse L3 emitted in the non-processing direction in the laser deflection unit 3.

Reference numeral 6 is an overall control unit for controlling the operation of the entire apparatus, and inside the unit, laser oscillation control for outputting a laser oscillation command signal S for instructing oscillation and attenuation of the laser pulse L1 in the laser oscillator 2 is performed. Unit 7, AOM control unit 8 that outputs the AOM drive signal D for controlling the operation of the laser deflection unit 3, galvano control unit 9 that outputs the galvano control signal G for controlling the drive operation of the galvano scanner 4, and galvano. Each time the operation control signal G is turned on and driven, the time until the positioning operation of the next galvano scanner 4 is completed is calculated from the information of the next drilling position given by the galvano control unit 9, and the positioning operation is performed. A positioning completion prediction unit 10 for predicting the completion time is provided.

The overall control unit 6 is configured around a computer that executes a program stored in the program storage unit 11, and each component and connection line in the computer includes logical ones.
That is, the laser oscillation control unit 7, the AOM control unit 8, the galvano control unit 9, and the positioning completion prediction unit 10 have a logical configuration in which the computer executes the program stored in the program storage unit 11 to perform their respective functions. It is an element.
It should be noted that some of these components may be provided separately from the overall control unit 6, or may be configured by hardware.
It is assumed that the overall control unit 6 has a control function other than that described here, and is also connected to a block (not shown).

According to the present invention, the laser pulse L1 oscillated from the laser oscillator 2 will be described in detail later, but for processing to oscillate for use in processing and for dummy to oscillate to suppress adverse effects due to fluctuations in thermal lens action. There are two types.
The AOM control unit 8 operates to turn off the AOM drive signal D during the period in which the dummy laser pulse is oscillated, and the dummy laser pulse is emitted in the non-processing direction in the laser deflection unit 3. It is absorbed by the damper 5.

FIG. 6 is a timing chart when a laser pulse for processing is oscillated from the laser oscillator 2 in the laser drilling apparatus of FIG.
In this laser drilling device, laser oscillation is performed in synchronization with the stop of rotation in the galvano scanner 4 to irradiate the printed circuit board 1.
In FIG. 6, under the control of the overall control unit 6, the galvano operation control signal G is turned on, the galvano scanner 4 rotates, and when the galvano scanner 4 rotates to the target position and the positioning operation is completed, the galvano operation control is completed. The signal G is turned off, the laser oscillation command signal S from the laser oscillation control unit 7 is turned on for a predetermined time after the time t10, and the laser oscillator 2 is instructed to oscillate the laser pulse for processing.

Then, the laser pulse L1 is oscillated from the laser oscillator 2 after a time t20 after the laser oscillation command signal S is turned on, and the AOM drive signal D is turned on for a predetermined time after the time t30. From the laser deflection unit 3, the laser pulse L2 deflected in the processing direction is applied to the printed circuit board 1 via the galvano scanner 4. After that, the galvano operation control signal G is turned on after a predetermined time t40 from the off of the laser oscillation command signal S, the galvano scanner 4 is rotated for irradiation to the next hole position, and so on.
Here, the times t10 to t30 include the processing / response time in the related functional elements and the signal propagation time between the functional elements, respectively.

Note that FIG. 6 does not show the control sequence when the dummy laser pulse is oscillated from the laser oscillator 2, but it is as follows.
That is, at this time, the galvano operation control signal G remains off, the laser oscillation command signal S is turned on for a time corresponding to the pulse width of the dummy laser pulse, and the dummy laser pulse is oscillated by the laser oscillator 2. A dummy laser pulse is oscillated from the laser oscillator 2 after a time corresponding to the time t20 after the laser oscillation command signal S is turned on. At this time, as described above, the AOM drive signal D remains off, and the dummy laser pulse is emitted in the non-processing direction in the laser deflection unit 3 and absorbed by the damper 5.

1 (a) to 1 (d) are timing charts for explaining the state of oscillation of the laser pulse L1 in the laser drilling apparatus of FIG. 5, which controls the laser oscillation control unit 7 as shown in FIGS. 2 to 4. It is realized by controlling according to the flow chart.
In FIGS. 1A to 1D, for the sake of simplicity, the waveform of the laser pulse L1 oscillated from the laser oscillator 2 is rectangular, and only the galvano operation control signal G and the laser pulse L1 are shown. FIG. T10 and t20 are set to zero, and the time point at which the positioning operation of the galvano scanner 4 is actually completed coincides with the time point predicted by the positioning completion prediction unit 10.
The same applies to the explanation of the same type of figure below.

In FIG. 5, the positioning completion prediction unit 10 grasps the oscillation time point each time the laser pulse for processing is oscillated from the laser oscillator 2, and each time the galvano operation control signal G is turned on and driven. Based on the information on the next drilling position given by the galvano control unit 9, the time T from the start of oscillation of the laser pulse for machining oscillated before that to the time when the positioning operation of the next galvano scanner 4 is completed is calculated. (Routine R1 in FIG. 2). It should be noted that this time T includes the settling time for completely matching the galvano scanner 4 with the target position.

FIG. 1A shows the time to be secured when the laser oscillator 2 reoscillates in the shortest time after T1 from the time when the positioning operation completion prediction time A of the galvano scanner 4 is predicted to complete the oscillation of the laser pulse for the previous processing. Assuming T0, T1 / T0 (= n) <1, that is, T1 is shorter than the time T0 by the time t1.
In this case, the laser oscillator 2 does not oscillate the laser pulse at the positioning operation completion prediction time point A, and the positioning operation is delayed by time t1 from the time T0 after the previous processing laser pulse, that is, the positioning operation completion prediction time point A. At the time of completion, a laser pulse having a normal pulse width is oscillated for processing (routine R2 in FIG. 2).

Although not shown in FIG. 1, when T1 / T0 (= n) = 1, a laser pulse having a normal pulse width is oscillated for processing when the positioning operation is completed (routine R2 in FIG. 2).
In addition, in FIG. 1A, it is assumed that the laser pulse in which the pulse width is not described has a normal pulse width, and the same applies to the following figures.

In FIG. 1 (b), 1 <T2 / T0 (= n) <2, that is, T2 is 1 after T2 from the time when the positioning operation completion prediction time B of the galvano scanner 4 is predicted to complete the oscillation of the laser pulse for the previous processing. This is a case where it is larger than the time of × T0 and shorter by the time of t2 than the time of 2 × T0.
In this case, the laser oscillator 2 first oscillates a laser pulse having a pulse width Td2 shorter than that of the normal laser pulse as a dummy after a time T0 from the start of oscillation of the laser pulse for the previous processing (routine R3 in FIG. 3). ), Then, at the time when the positioning operation is completed B, a laser pulse having a normal pulse width is oscillated for processing (routine R2 in FIG. 2). Here, the pulse width Td2 of the laser pulse for the dummy is set to a length at which the duty is constant during these periods.
In FIG. 1 (b), the dummy pulse is shaded, and the same applies to the following similar figures.

Although not shown in FIG. 1, when the time point of predicting the completion of the positioning operation of the galvano scanner 4 is an integral multiple of 2 or more with respect to T0 from the time point of the oscillation start of the laser pulse for the previous processing, the laser oscillator 2 is the previous time. Every time T0 elapses from the start of oscillation of the laser pulse for processing, a laser pulse with a normal pulse width is oscillated as a dummy pulse until the last T0 remains (routine R4 in FIG. 3), and then at the time when the positioning operation is completed. A laser pulse having a normal pulse width is oscillated for processing (routine R2 in FIG. 2).

FIG. 1 (c) shows the time when T3 = 3 × T0-t3, that is, T3 becomes 3 × T0 after T3 from the time when the positioning operation completion prediction time C of the galvano scanner 4 is predicted to complete the oscillation of the laser pulse for the previous processing. This is the case where the time is shorter than t3.
In this case, the laser oscillator 2 first oscillates a laser pulse having a normal pulse width as a dummy after a time T0 from the start of oscillation of the laser pulse for the previous processing (routine R5 in FIG. 4), and then further normal. A laser pulse having a shorter pulse width of Td3 is oscillated for dummy use (routine R3 in FIG. 3), and then a laser pulse having a normal pulse width is oscillated for processing at the time when the positioning operation is completed C (routine R2 in FIG. 2). ). Here, the pulse width Td3 of the laser pulse for the dummy is set to a length at which the duty is constant during these periods.

FIG. 1 (d) shows the time when the positioning operation completion prediction time D of the galvano scanner 4 is T4 after the oscillation start time of the laser pulse for the previous machining, T4 = 4 × T0−t4, that is, T4 becomes 4 × T0. This is the case where the time is t4 earlier.
In this case, the laser oscillator 2 first oscillates a laser pulse having a normal pulse width as a dummy every time T0 elapses from the start of oscillation of the laser pulse for processing last time. That is, a laser pulse having a normal pulse width was oscillated twice for a dummy (routine R5 in FIG. 4), and then a laser pulse having a pulse width Td4 shorter than usual was oscillated for a dummy after a further time T0 (FIG. 4). After the routine R3) in 3, a laser pulse having a normal pulse width is oscillated for processing at the time point D when the positioning operation is completed (routine R2 in FIG. 2). Here, the pulse width Td4 of the laser pulse for the dummy is set to a length at which the duty is constant during these periods.

As described above, the laser oscillation control unit 7 sets the time from the start of oscillation of the laser pulse for the previous processing to the prediction of the completion of the next positioning operation as T, n as an integer of 2 or more, and n × T0>T>. Assuming (n-1) × T0, every time the time T0 elapses from the start of oscillation of the laser pulse for the previous processing, a laser pulse having a normal pulse width is used as a dummy (n-2) times, and further. Subsequently, a laser pulse having a pulse width shorter than that of the normal laser pulse is oscillated once for the dummy, and a laser pulse having the normal pulse width is oscillated for processing when the positioning operation is completed.
When T ≦ T0, the dummy laser pulse is not oscillated, and only the laser pulse having a normal pulse width is oscillated for processing after the time T0 from the previous laser pulse.
Therefore, although FIGS. 1 (a) to 1 (d) do not show after the laser pulse having the normal pulse width for the second processing, the oscillation of the laser oscillator 2 is controlled according to the above rule. Needless to say.

According to the above configuration, the laser oscillator 2 uses a laser pulse having the same pulse width as the laser pulse for processing for the dummy, and repeatedly oscillates the laser pulse for processing and the laser pulse for the dummy with a period of time T0. Basically, a laser pulse having a pulse width shorter than that of a normal laser pulse is oscillated as a dummy only in the case where the time T0 cannot be secured only once, and the duty of the period does not change.
Therefore, the output duty of the laser oscillator 2 becomes constant, the energy received by the laser deflection unit 3 can be made constant, and the adverse effect due to the fluctuation of the thermal lens action can be suppressed.

In the above description, for the sake of simplicity, the time point at which the positioning operation of the galvano scanner 4 is actually completed is assumed to completely coincide with the time point at which the positioning operation is completed predicted by the positioning completion prediction unit 10. .. The laser pulse having a normal pulse width is oscillated for processing only at the time when the positioning operation of the galvano scanner 4 is actually completed, and may be slightly different from the predicted time when the positioning operation is completed. Therefore, if the oscillation of the laser oscillator 2 is controlled based on the prediction at the completion of the positioning operation, the output data may not always be in accordance with the theoretical value, but even if the deviation is small, the deviation is small, which causes a practical problem. It is possible to suppress the adverse effect due to the fluctuation of the thermal lens action.

Example 2
Next, Example 2 of the present invention will be described. FIG. 7 is a block diagram of the laser drilling device according to the second embodiment. The same items as in FIG. 5 are numbered the same. This laser drilling device is a so-called biaxial laser drilling device that aims to increase the speed by performing machining at two locations in parallel. FIG. 8 is a timing chart for explaining the state of oscillation of the laser pulse L1 in the laser drilling device of FIG. 7.

In FIG. 7, 1-A and 1-B are printed circuit boards to be processed, respectively. Hereinafter, the system for processing the printed circuit board 1-A is referred to as an A axis, and the system for processing the printed circuit board 1-B is referred to as a B axis. Reference numeral 12 is a beam spiriter that divides the laser pulse oscillated from the laser oscillator 2 in two directions, and 3-A and 3-B respectively deflect the laser pulse output from the beam spiriter 12 from the non-machining direction to the machining direction. It is an AOM, and the laser deflection units 3-A and 3-B can simultaneously receive a laser pulse from the laser oscillator 2.
4-A and 4-B change the laser irradiation position of the laser pulse deflected in the processing direction in the laser deflection portions 3-A and 3-B, respectively, and the printed substrates 1-A and 1-B according to the processing data. It is a galvano scanner as an optical scanner that is rotationally driven so as to irradiate a drilling position.

The A-axis and B-axis constitute one axis group (hereinafter referred to as an axis pair) capable of simultaneously receiving a laser pulse from the laser oscillator 2, and the galvano scanners 4-A and 4-B respectively have laser deflection. It constitutes one galvano scanner group capable of simultaneously receiving laser pulses from parts 3-A and 3-B. When the laser deflection unit 3-A deflects the laser pulse from the beam spiriter 12 to the galvano scanner 4-A of the A-axis system, the laser deflection unit 3-B starts from the beam spiriter 12 at the same time. The laser pulse of is deflected to the galvano scanner 4-B of the B-axis system.
Although the AOM control unit 8 and the galvano control unit 9 are shown only for the B-axis system for the sake of simplicity in the figure, they are also provided in the A-axis system, respectively. Further, the positioning completion prediction unit 10 can predict the positioning operation completion time points of the galvano scanners 4-A and 4-B, and may be provided in each of the galvano scanners 4-A and 4-B.

In FIG. 7, the A-axis system and the B-axis system independently perform machining operations in parallel. That is, the galvano scanners 4-A and 4-B each perform a positioning operation based on different machining data under the control of the corresponding galvano control unit 9. Therefore, as shown in FIG. 8, even if the galvano scanners 4-A and 4-B start the positioning operation at the same time, the positioning operation completion time points are not always the same.
According to the present invention, in the case of a system including a plurality of galvano scanners capable of simultaneously receiving laser pulses from the laser oscillator 2, the laser oscillator is based on the positioning operation completion prediction time point at which the positioning operation completion is the latest among the galvano scanners. A laser pulse is oscillated from 2.

For example, as shown in FIG. 8, when the positioning operation completion prediction time point F of the galvano scanner 4-A is later than the positioning operation completion time point E of the galvano scanner 4-B, the laser oscillation control unit 7 , The laser pulse is oscillated based on the positioning completion prediction time point F of the galvano scanner 4-A whose positioning operation completion time is late.
The positioning operation completion prediction time point F here is the case of FIG. 1 (d).

The laser oscillation control unit 7 in the second embodiment is realized by changing and controlling the portion of the step 20 in the routine R1 in FIG. 2 in the control flowchart in the first embodiment as follows.
That is, in the part of step 20, each time the galvano operation control signal G in each of the galvano scanners 4-A and 4-B is turned on and driven, the next galvano control unit 9 corresponding to each is given. Based on the drilling position information, calculate the positioning completion time of the next galvano scanners 4-A and 4-B from the oscillation start time of the laser pulse for processing oscillated before that, and select the later one as T. .. If they are equal, let it be T.

Example 3
Next, Example 3 of the present invention will be described. FIG. 9 is a block diagram of the laser drilling device according to the third embodiment. The same numbers as those in FIGS. 5 and 7 are assigned. This laser drilling device is a so-called 4-axis type laser drilling device that aims to increase the speed by performing machining at four locations in parallel. 10 and 11 are timing charts for explaining the state of laser pulse oscillation in the laser drilling apparatus of FIG.

In FIG. 9, 1-C to 1-F are printed circuit boards to be processed, respectively. Hereinafter, the systems for processing the printed circuit boards 1-C to 1-F are referred to as C-axis to F-axis, respectively. The 3-CD and 3-EF are AOMs that deflect the laser pulse output from the beam spiriter 12 from the non-processing direction to the processing direction, respectively, and the laser deflection units 3-CD and 3-EF are lasers from the laser oscillator 2. Pulses can be received at the same time. As will be described later, the laser deflection portions 3-CD and 3-EF each have two processing directions.
4-C and 4-D change the laser irradiation position of the laser pulse deflected in the processing direction in the laser deflection unit 3-CD, respectively, and irradiate the drilling positions of the printed substrates 1-C and 1-D according to the processing data. It is a galvano scanner as an optical scanner that is rotationally driven so as to be. Further, 4-E and 4-F change the laser irradiation position of the laser pulse deflected in the machining direction in the laser deflection section 3-EF, respectively, and set the drilling positions of the printed substrates 1-E and 1-F according to the machining data. It is a galvano scanner as an optical scanner that is rotationally driven to be irradiated.

The C-axis and the E-axis, and the D-axis and the F-axis, respectively, constitute one axis group (hereinafter referred to as an axis pair) capable of simultaneously receiving a laser pulse from the laser oscillator 2. That is, the galvano scanners 4-C and 4-E can simultaneously receive laser pulses from the laser deflection units 3-CD and 3-EF, respectively, while the galvano scanner group CE, galvano scanners 4-D and 4-F are capable of receiving laser pulses at the same time. The other galvano scanner group DF, which can simultaneously receive laser pulses from the laser deflection units 3-A and 3-B, respectively, is configured.

When the laser deflection unit 3-CD deflects the laser pulse from the beam spiriter 12 to the galvano scanner 4-C of the C-axis system, the laser deflection unit 3-EF is directed from the beam spiriter 12 at the same time. The laser pulse of is deflected to the galvano scanner 4-E of the E-axis system. Although the timing is different from this, when the laser deflection unit 3-CD deflects the laser pulse from the beam spiriter 12 to the galvano scanner 4-D of the D-axis system, the laser is performed at the same time. The deflection unit 3-EF is adapted to deflect the laser pulse from the beam spiriter 12 to the galvano scanner 4-F of the F-axis system.
The AOM control unit 8 and the galvano control unit 9 are provided for all the axis systems, although only one for the F axis system is shown for simplification of the figure. Further, the positioning completion prediction unit 10 can predict the positioning operation completion time points of the galvano scanners 4-C, 4-D, 4-E, and 4-F, and the galvano scanners 4-C, 4-D, and 4 It may be provided in each of -E and 4-F.

In FIG. 9, each axis system independently performs machining operations in parallel. That is, the galvano scanners 4-C to 4-F perform positioning operations based on different machining data under the control of the corresponding galvano control unit 9. Therefore, even if the galvano scanners 4-C to 4-F start the positioning operations at the same time, the respective positioning completion points are usually different.
According to the present invention, in the case of a system including a plurality of galvano scanners capable of simultaneously receiving laser pulses from the laser oscillator 2, the galvano scanner group in which the positioning operation of all the galvano scanners belonging to each of the galvano scanner groups is completed earliest. A laser pulse is oscillated from the laser oscillator 2 based on the positioning completion prediction time point of the galvano scanner in which the positioning operation (hereinafter referred to as the fastest group) is completed at the latest.

For example, as shown in FIG. 10, if the completion of positioning is in the order of galvano scanners 4-E, 4-C, 4-D, 4-F, it belongs to each of the galvano scanner groups CE and DF. The positioning operation of all the galvano scanners is completed earlier. The positioning operation in the galvano scanner group CE is completed later. The laser pulse from the laser oscillator 2 is based on the time H until the position prediction completion time of the galvano scanner 4-C. To oscillate.
At this time, the laser deflection unit 3-CD is controlled to distribute the laser pulse in the processing direction of the C-axis system, and the laser deflection unit 3-EF is controlled to distribute the laser pulse in the processing direction of the E-axis system, respectively, and the printed circuit boards 1-C and 1-E are controlled. Is processed into.
The positioning operation completion prediction time point H here is the case of FIG. 1 (d).

Further, for example, as shown in FIG. 11, assuming that the completion of the positioning operation is in the order of the galvano scanners 4-D, 4-F, 4-E, and 4-C, among the galvano scanner group CE and DF, The laser oscillator is based on the time N until the position prediction completion time of the galvano scanner 4-F, in which the positioning operation of all the galvano scanners belonging to each is completed earlier and the positioning operation of the galvano scanner group DF is completed later. A laser pulse is oscillated from 2.
At this time, the laser deflection unit 3-CD is controlled to distribute the laser pulse in the processing direction of the D-axis system, and the laser deflection unit 3-EF is controlled to distribute the laser pulse in the processing direction of the F-axis system, respectively, and the printed circuit boards 1-D and 1-F are controlled. Is processed into.
The positioning operation completion prediction time point N here is the case of FIG. 1 (d).

According to the present invention, after the oscillation of the laser pulse for processing for the galvano scanner which became the fastest group for the first time by the above, it becomes as follows.
The positioning completion prediction time points of all galvano scanners belonging to the galvano scanner group that became the fastest group this time are newly predicted based on the oscillation start time point of the laser pulse for this processing, and the galvano that did not become the fastest group. Re-predict the positioning operation completion prediction time of all galvano scanners belonging to the scanner group.
Then, these positioning operation completion prediction time points are compared, and among all the galvano scanners belonging to the galvano scanner group which is the fastest group again, the positioning operation is completed slowly based on the time until the positioning operation completion prediction time of the galvano scanner. , Laser pulse is oscillated in the laser oscillator 2.

For example, as shown on the right side of FIG. 10, the positioning operation completion prediction of the galvano scanners 4-C and 4-E belonging to the galvano scanner group CE, which is the fastest group, is predicted based on the oscillation start time of the laser pulse for this processing. The time points TC-S and TE-S are newly predicted, and the time points TD-S and TF-S for predicting the completion of the positioning operation of the galvano scanners 4-D and 4-F belonging to the galvano scanner group DF that did not become the fastest group are determined. Re-predict each.
The fastest group of galvano scanners did not reach the fastest group before the lapse of time T0 from the start of oscillation of the laser pulse for processing oscillated based on the completion of the positioning operation of the galvano scanner 4-C belonging to the galvano scanner group CE. If both the galvano scanners 4-D and 4-F belonging to the galvano scanner group DF complete the positioning operation, it becomes the case of FIG. 1A, and when the time T0 elapses, it is used for processing for the galvano scanner group DF. The laser pulse of is oscillated.

Further, for example, as shown on the right side of FIG. 11, the positioning operation of the galvano scanners 4-D and 4-F belonging to the galvano scanner group DF, which is the fastest group, based on the oscillation start time of the laser pulse for this processing. Positioning operation of galvano scanners 4-C and 4-E belonging to the galvano scanner group CE, which newly predicted the completion prediction time points TD-S and TF-S and did not become the fastest group. Repredict each S.
In any galvano scanner group, at the time when time T0 elapses from the start of oscillation of the laser pulse for processing oscillated based on the completion of the positioning operation of the galvano scanner 4-F belonging to the galvano scanner group DF which became the fastest group. If both of the galvano scanners belonging to the galvano scanner do not complete the positioning operation, the case of any one of FIGS. 1 (b) to 1 (d) occurs, and a dummy laser pulse having a pulse width shorter than normal or normal is oscillated.
In this case, the dummy laser pulse is assumed to be a dummy laser pulse having a normal pulse width, which is not described in FIG. 11.

The laser oscillation control unit 7 in the third embodiment is realized by changing and controlling the portion of the step 20 in the routine R1 in FIG. 2 in the control flowchart in the first embodiment as follows.
That is, in the part of step 20, each time the galvano operation control signal G in each of the galvano scanners 4-C, 4-D, 4-E, and 4-F is turned on and driven, the galvano corresponding to each is turned on. Based on the information on the next drilling position given by the control unit 9, the next galvano scanners 4-C, 4-D, 4-E, and 4-FB from the start of oscillation of the laser pulse for machining that was oscillated before that. The time point at which the positioning operation is completed may be calculated, and the time point at which the positioning operation is completed in the galvano scanner in which the positioning operation is completed later in the fastest group may be selected and set to T.
If the positions at which the positioning operations of the galvano scanners are completed in the fastest group are all the same, it may be set to T. Further, if all of the fastest groups are equal to each other, the time point at which the positioning operation of the galvano scanner is completed in one of the fastest groups may be selected and set to T according to a predetermined priority.

According to the above-mentioned Examples 2 and 3, a plurality of optical scanners for changing the laser irradiation position of the laser pulse from the laser oscillator distributed in the processing direction are provided, and processing or processing of each of the plurality of printed substrates is performed. Even in a so-called multi-axis laser processing device that aims to increase the speed by processing multiple locations separated by a predetermined distance in parallel on one printed substrate, the output data of the laser oscillator becomes constant and AOM. The energy received by the laser can be kept constant, and the adverse effects of the thermal lens action can be suppressed.

In the above examples, t10 and t20 in FIG. 6 have been described as zero. However, as already described, in reality, a time delay of t10 + t20 occurs from the time when the galvano operation control signal G is turned off until the laser pulse for processing is oscillated by the laser oscillator 2.
FIG. 12 is a timing chart when a laser pulse for processing is oscillated from a laser oscillator in a laser drilling apparatus according to another embodiment of the present invention, but in the case of FIGS. 1 (b) to 1 (d). In consideration of the time delay, the control sequence of FIG. 6 may be started early without waiting for the timing of predicting the completion of the positioning operation of the galvano scanner, whereby the machining operation can be speeded up.

In FIG. 12, the laser oscillation control unit 7 outputs the laser oscillation command signal S to the laser oscillator 2 at a time time t50 earlier than the positioning operation completion prediction time when the galvano operation control signal G is turned on. The laser oscillator 2 outputs the laser pulse L1 after a time t60 after the laser oscillation command signal S is turned on, and turns on the AOM drive signal D for a predetermined time after the time t70. A laser pulse L2 deflected in the machining direction is incident on the galvano scanner 4 from the AOM3. After that, the galvano operation control signal G is turned on after a predetermined time t80 from the off of the laser oscillation command signal S, and the galvano scanner 4 is rotated for irradiation to the next hole position.
The predetermined time t50 is smaller than the time t70 from when the laser oscillation command signal S is turned on to when the AOM drive signal D is turned on. Otherwise, the laser pulse L2 will be output before the galvano scanner 4 completes the positioning operation, resulting in malfunction.

Further, in the above embodiment, the case where the printed circuit board is drilled has been described, but the present invention is not limited to this, and can be provided for laser machining in which a plurality of workpieces are sequentially machined.
Although the present invention has been specifically described above based on the embodiments, it goes without saying that the present invention is not limited to the above-described embodiments and can be variously modified without departing from the gist thereof. , Various variants are included.

1, 1-A, 1-B, 1-C to 1-F: printed circuit board, 2: laser oscillator,
3,3-A, 3-B, 3-CD, 3-EF: Laser deflection section,
4, 4-A, 4-B, 4-C to 4-F: Galvano scanner, 5: Damper,
6: Overall control unit, 7: Laser oscillation control unit, 8: AOM control unit, 9: Galvano control unit, 10: Positioning completion prediction unit, 11: Program storage unit, 12: Beam spiriter S: Laser oscillation command signal, G: Galvano operation control signal, D: AOM drive signal,
L1 to L3: laser pulse, R1 to R5: routine

Claims (8)

A laser oscillator that oscillates a laser pulse, and an optical scanner in which the laser pulse is incident via an optical element, which is driven to irradiate a processing position on a workpiece according to processing data, and the above. In a laser processing apparatus including a laser oscillation control unit that controls the oscillation of the laser pulse by the laser oscillator and that oscillates the laser pulse for processing in synchronization with the completion of the positioning operation in the optical scanner. It has a positioning completion prediction unit that predicts the time point at which the positioning operation in the optical scanner is completed with reference to the time point at which the laser pulse for processing is oscillated each time the optical scanner is newly driven. The laser oscillation control unit is used when the time T from the oscillation time point to the positioning operation completion prediction time point is n × T0>T> (n-1) × T0 (T0 is a predetermined time, n is an integer of 2 or more). The first laser pulse having the same pulse width as the machining laser pulse is sent n-2 times, and then the second laser pulse having a pulse width shorter than that of the machining laser pulse is sent once. Each time the predetermined time T0 elapses in the time until the completion prediction time, the laser oscillator is oscillated as a dummy pulse, and the second laser pulse adjusts the duty until the subsequent processing laser pulse is oscillated. A laser processing apparatus characterized by having a pulse width for. In the laser processing apparatus according to claim 1, the laser pulse is simultaneously incident on a plurality of the optical scanners from the optical element, and the laser oscillation control unit completes the positioning operation among the plurality of optical scanners. A laser processing apparatus characterized in that the time at which the predicted time is the latest is controlled as the T. In the laser processing apparatus according to claim 1, a plurality of the optical scanners form an optical scanner group in which the laser pulse is simultaneously incident from the optical element, and the laser is provided. The oscillation control unit positions all the optical scanners belonging to each of the optical scanner groups among the plurality of optical scanner groups in the optical scanner group having the earliest prediction time of completion of the positioning operation. A laser processing apparatus characterized in that the time based on the positioning completion prediction time of the optical scanner having the latest operation completion prediction time is controlled as T. In the laser processing apparatus according to any one of claims 1 to 3, the predetermined time T0 is a time to be secured when the laser oscillator reoscillates in the shortest time. Laser processing equipment. In the laser processing apparatus according to any one of claims 1 to 4, the laser oscillation control unit commands the laser oscillator to oscillate the laser pulse before the timing of predicting the completion of the positioning operation. Laser processing equipment. The laser pulse oscillated by the laser oscillator is incident on the optical scanner driven to irradiate the processed position on the workpiece according to the processed data via the optical element, and the positioning operation in the optical scanner is completed. In a laser processing method in which a laser pulse for processing is oscillated to the laser oscillator in synchronization with each other, the light is used as a reference at the time of oscillation of the laser pulse for processing each time the optical scanner is newly driven. The time point at which the positioning operation on the scanner is completed is predicted, and the time T from the oscillation time point to the positioning operation completion prediction time point is n × T0>T> (n-1) × T0 (T0 is a predetermined time, n). Is an integer of 2 or more), the first laser pulse having the same pulse width as the machining laser pulse is sent n-2 times, and then the second laser pulse having a pulse width shorter than that of the machining laser pulse is sent 1 times. Each time T0 elapses in the time from the oscillation time to the positioning operation completion prediction time, the laser oscillator is oscillated as a dummy pulse, and the second laser pulse is followed by the processing laser pulse. A laser processing method characterized by having a pulse width for adjusting the duty until oscillation. The laser pulse oscillated by the laser oscillator is incident on the optical scanner driven to irradiate the processed position on the workpiece according to the processed data via the optical element, and the positioning operation in the optical scanner is completed. In a program for a laser processing method in which a laser pulse for processing is oscillated to the laser oscillator in synchronization, the program oscillates the laser pulse for processing each time the optical scanner is newly driven. The time point at which the positioning operation in the optical scanner is completed is predicted with reference to the time point, and the time T from the oscillation time point to the positioning operation completion prediction time point is n × T0>T> (n-1) × T0 ( When T0 is a predetermined time and n is an integer of 2 or more), the first laser pulse having the same pulse width as the machining laser pulse is repeated n-2 times, and the pulse width is shorter than that of the machining laser pulse. The second laser pulse is oscillated once to the laser oscillator as a dummy pulse each time the predetermined time T0 elapses in the time from the oscillation time to the positioning operation completion prediction time, and the second laser pulse follows. A program for a laser processing method comprising controlling the oscillation of the laser oscillator so as to have a pulse width for adjusting the duty until the processing laser pulse is oscillated. The laser pulse oscillated by the laser oscillator is incident on the optical scanner driven to irradiate the processed position on the workpiece according to the processed data via the optical element, and the positioning operation in the optical scanner is completed. In a storage medium in which a program is stored for a laser processing method in which a laser pulse for processing is oscillated to the laser oscillator in synchronization, the program is used for processing each time the optical scanner is newly driven. The time point at which the positioning operation in the optical scanner is completed is predicted based on the time point at which the laser pulse is oscillated, and the time T from the time point of oscillation to the time point at which the positioning operation completion is predicted is n × T0>T> (n−). 1) In the case of × T0 (T0 is a predetermined time, n is an integer of 2 or more), the first laser pulse having the same pulse width as the processing laser pulse is performed n-2 times in succession from the processing laser pulse. A second laser pulse having a short pulse width is oscillated once by the laser oscillator as a dummy pulse each time the predetermined time T0 elapses in the time from the oscillation time to the positioning operation completion prediction time. (Ii) A program for a laser processing method, characterized in that the laser pulse controls the oscillation of the laser oscillator so as to have a pulse width for adjusting the duty until the subsequent processing laser pulse is oscillated. A stored storage medium.

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