JP2022174903A - Laser machining device, laser machining method, program, and storage medium - Google Patents

Abstract

To improve machining quality by suppressing the effect of fluctuation of a thermal lens operation at an acoustic optical element.SOLUTION: Time T until the completion time point of a positioning operation for positioning a deflector toward a next machining position of a machining position is predicted. When the time T is an integer n of 2 or more and n×T0>T>(n-1)×T0 with respect to prescribed time T0, emitting a first dummy pulse with the same pulse width Tp as that of a machining laser pulse from a laser oscillator is repeated by (n-1) times for each passage of the time T0, and then a second dummy pulse is emitted from the laser oscillator with a pulse width Td shorter than the pulse width Tp. When a product (Tr×D0) of a remainder Tr obtained by dividing the time T with the time T0 and a duty D0 of the pulse width Tp with respect to the time T0 is less than a threshold value Td_min, a pulse width Td2 of the second dummy pulse is set equal to the threshold value Td_min, and an output start of a machining laser pulse for irradiation at the next machining position is delayed.SELECTED DRAWING: Figure 2

Description

The present invention relates to a laser processing apparatus for processing a workpiece using laser light, a laser processing method, a program for the laser processing method, and a storage medium storing the program for the laser processing method.

Conventionally, as a laser processing apparatus, there is known one in which the optical path of a laser pulse emitted from a laser oscillator is switched between a processing direction toward a workpiece and a non-processing direction away from the workpiece by an acoustooptic device. In this type of laser processing apparatus, it is known that the acousto-optic element absorbs the laser pulse and generates heat to act as a lens (thermal lens effect). Temporal variations in the thermal lensing action on the acousto-optic device can degrade the processing quality of the workpiece.

Patent Document 1 discloses a laser processing apparatus that processes a plurality of processing positions on a workpiece by deflecting a laser pulse deflected in a processing direction by an acousto-optic device by a galvanometer scanner. It is described that a dummy pulse that is not used for processing the workpiece is emitted from the laser oscillator during the period in which the galvano-scanner is positioned toward . According to this document, during the operation period of the galvanometer scanner, dummy pulses are applied to the acousto-optic element with the same duty as the laser pulse for processing, and by adjusting the pulse width of the last dummy pulse in the period, The duty is constant throughout the period during which the object to be processed is processed and during the operation period of the galvano-scanner, and fluctuations in the thermal lens effect on the acousto-optic element are suppressed.

JP 2019-107693 A

In the above document, depending on the length of the operation period of the galvano-scanner, the pulse width of the last dummy pulse during the period may become very short. However, as shown in FIG. 5, it takes a certain amount of time from when the oscillation command S to the laser oscillator is turned on to when the laser oscillator actually starts emitting laser light, depending on the specific configuration of the laser oscillator. There is a lag Δt. Therefore, when the emission of a dummy pulse with a very short pulse width is instructed according to the control of the above document, the pulse width of the actually emitted dummy pulse becomes shorter than the instructed pulse width, or the dummy pulse is actually It may not be emitted. For this reason, if the amount of energy of the laser pulse incident on the acousto-optic device per unit time fluctuates, the effects of fluctuations in the thermal lens effect on the acousto-optic device may not be sufficiently suppressed, resulting in deterioration of processing quality. There is

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to improve processing quality by suppressing the influence of variations in thermal lens action in an acousto-optic device.

A laser processing apparatus according to an aspect of the present invention includes a laser oscillator that emits a laser pulse, an acousto-optic element that switches an optical path of the laser pulse emitted from the laser oscillator between a machining direction and a non-machining direction, and the acoustic A deflector that deflects the laser pulse emitted from the optical element in the processing direction so as to irradiate the workpiece, a control means that controls the laser oscillator, and the laser oscillator irradiates the laser pulse to the machining position of the workpiece. prediction means for predicting the time T until the completion of the positioning operation for positioning the deflector toward the processing position next to the processing position, based on the output start time of the processing laser pulse for the processing; and the control means controls the processing laser when the value of the time T satisfies n×T0>T>(n−1)×T0 for an integer n of 2 or more and a predetermined time T0 Every time the predetermined time T0 passed from the output start point of the pulse, the laser oscillator was caused to emit a first dummy pulse with the same pulse width Tp as that of the processing laser pulse, which was repeated (n−1) times. After that, the laser oscillator emits a second dummy pulse with a pulse width Td shorter than the pulse width Tp, and the control means outputs a remainder Tr obtained by dividing the time T by the predetermined time T0 and the pulse width Tp. When the product (Tr×D0) of the predetermined time T0 and the duty D0 is less than a predetermined threshold value Td_min, the pulse width Td2 of the second dummy pulse is set to the threshold value Td_min, and the processing and causing the laser oscillator to emit a processing laser pulse for irradiating the next processing position at a time point after the time T has elapsed from the output start time of the laser pulse for processing. .

Further, in the laser processing method according to one aspect of the present invention, an optical path of a laser pulse emitted from a laser oscillator is switched between a processing direction and a non-processing direction by an acoustooptic device, and the laser pulse emitted in the processing direction is In the laser processing method for processing the work piece by irradiating the work piece with deflection by a deflector, the output start time of the processing laser pulse for irradiating the processing position of the work piece by the laser oscillator. is used as a reference to predict the time T until the positioning operation for positioning the deflector toward the processing position next to the processing position is completed, and the value of the time T is an integer n of 2 or more and a predetermined When n×T0>T>(n−1)×T0 with respect to time T0, every time the predetermined time T0 elapses from the output start point of the laser pulse for processing, the laser pulse for processing and After repeating (n-1) times to cause the laser oscillator to emit a first dummy pulse with the same pulse width Tp, a second dummy pulse is emitted to the laser oscillator with a pulse width Td shorter than the pulse width Tp. and when the product (Tr×D0) of the remainder Tr obtained by dividing the time T by the predetermined time T0 and the duty D0 of the pulse width Tp with respect to the predetermined time T0 is less than a predetermined threshold value Td_min, The pulse width Td2 of the second dummy pulse is set to the threshold value Td_min, and the next processing position is reached after the time T has elapsed from the output start time of the processing laser pulse. The laser oscillator is caused to emit a processing laser pulse for irradiating the laser.

According to the present invention, it is possible to improve the processing quality by suppressing the influence of fluctuations in the thermal lens action in the acousto-optic element.

1 is a diagram for explaining the structure of a laser processing apparatus according to an embodiment of the present disclosure; FIG. 4 is a timing chart showing how laser pulses are oscillated in a laser processing apparatus according to an embodiment of the present disclosure; 4 is a flow chart showing a control example of a laser processing apparatus according to an embodiment of the present disclosure; 4 is a flow chart showing a control example of a laser processing apparatus according to an embodiment of the present disclosure; FIG. 4 is a diagram for explaining a delay in the start of output of actual laser light with respect to a dummy pulse oscillation command;

Hereinafter, embodiments according to the present disclosure will be described based on examples with reference to the drawings. In addition, in the following description, the same code|symbol is attached|subjected to each equivalent part, and description is abbreviate|omitted.

FIG. 1 is a diagram showing the structure of a laser processing apparatus according to one embodiment of the present disclosure. This laser processing apparatus includes a table 2, a laser oscillator 3, an acousto-optic modulator (AOM) 4, a galvanometer scanner 5, a condenser lens 6, and controls the operation of the entire apparatus. The system includes an overall control unit 11 for

The table 2 is a portion on which a substrate 1 such as a printed circuit board, which is an example of a workpiece, is placed. On the table 2, a substrate is mounted on the substrate 1 in two-dimensional directions (directions X and Y perpendicular to each other when the substrate 1 is viewed from above in FIG. It includes a drive mechanism for moving 1.

AOM 4 is an optical element that deflects laser light L 1 emitted from laser oscillator 3 . The AOM 4 is driven by the AOM drive signal E output from the AOM control section 9 in the overall control section 11, and directs the optical path of the laser light L1 to the final direction toward the substrate 1 via a galvanometer scanner or the like (hereinafter referred to as processing direction) and the direction toward the damper 7D (non-machining direction). The laser beam L2 directed in the processing direction is the laser beam used for processing the substrate 1, and the laser beam L2' directed in the non-processing direction is the laser beam not used for processing the substrate 1. FIG. The damper 7D absorbs the laser beam L2' deflected in the non-processing direction. As the laser oscillator 3, a known laser oscillator such as a gas laser such as a CO ₂ laser can be used.

The galvano scanner 5 is controlled by the galvano operation control signal G output from the galvano control unit 10 in the overall control unit 11, and deflects the laser beam L2 deflected in the processing direction by the AOM 4 toward the processing position on the substrate 1. It is a deflector that The galvanometer scanner 5 has two mirrors (galvanometer mirrors) that rotate around rotation axes extending in mutually different directions, and controls the reflection direction of the laser light L2 so that any two-dimensional direction on the substrate 1 can be detected. The laser light L3 can be deflected towards the position. The condenser lens 6 converges the laser beam L3 deflected by the galvanometer scanner 5 onto the processing surface on the substrate 1 .

In the laser processing apparatus having such a configuration, the laser pulse emitted from the laser oscillator 3 is deflected in the processing direction by the AOM 4, and is irradiated onto the processing position on the substrate 1 via the galvanometer scanner 5, so that the substrate 1 Laser processing such as drilling is applied to the . Hereinafter, a laser pulse emitted from the laser oscillator 3 for use in processing the substrate 1 will be referred to as a "processing laser pulse". When processing a plurality of processing positions on the substrate 1, the galvanometer scanner 5 is driven and the substrate 1 is moved on the table 2 during a period in which the laser pulse for processing is not emitted, and the galvanometer scanner 5 and the substrate 1 are positioned. After completion, the laser pulse for processing is emitted again.

The overall control unit 11 is composed mainly of, for example, a program-controlled processing device, and each component therein (including the laser oscillation control unit 7, the AOM control unit 9, and the galvano control unit 10) and connection lines are logical It shall also include Moreover, a part of each component may be provided separately from this. It is also assumed that the overall control unit 11 has control functions other than those described here, and is also connected to blocks not shown.

The overall control unit 11 controls the laser oscillation control unit 7 as control means (laser oscillation control means) for outputting an oscillation command S for instructing the oscillation and attenuation of the laser light L1 in the laser oscillator 3, and the AOM 4. AOM control unit 9 as AOM control means for outputting AOM drive signal E for controlling galvano scanner 5; galvano control unit 10 as galvano control means for outputting galvano operation control signal G for controlling galvano scanner 5; and a positioning completion prediction unit 12 as prediction means for calculating the time required for the positioning operation and predicting the completion time of the positioning operation.

The positioning completion prediction unit 12 completes the next positioning operation of the galvano scanner 5 based on the information of the next processing position given from the galvano control unit 9 every time the galvano operation control signal G is turned on and driven. The time point (positioning operation completion time point) is predicted, and the time T until the positioning operation completion time point is calculated based on the output timing of the previous processing laser pulse. It should be noted that this time T includes a settling time for completely matching the galvanometer scanner 4 to the target position.

In this laser processing apparatus, in principle, the laser oscillator 3 emits a laser pulse for processing in synchronization with the stop of the galvanometer scanner 5 (completion of the positioning operation according to the processing position), and the substrate 1 is irradiated with the laser beam. , the laser oscillation control unit 7 controls the timing of outputting the oscillation command S. As shown in FIG. Here, if the emission of the laser pulse by the laser oscillator 3 is stopped while the galvanometer scanner 5 is waiting for the positioning operation to the next processing position, the unit becomes smaller than the period during which the laser pulse for processing is emitted. The amount of energy of the laser light incident on the AOM 4 per hour decreases, and the thermal lens action in the AOM 4 fluctuates, possibly leading to a decrease in machining accuracy. Therefore, in this laser processing apparatus, while the positioning operation of the galvanometer scanner 5 is on standby, the laser oscillator 3 emits a laser pulse that is not used for processing the substrate 1 as a dummy pulse (a discard pulse).

As will be described below, in this embodiment, when the galvano operation control signal G is turned on, the laser oscillator 3 is turned on every time a certain time (T0) elapses from the output timing of the previous processing laser pulse. By outputting a pulse and performing control so that the duty of the processing laser pulse and the duty of the dummy pulse are substantially equal, fluctuations in the thermal lens effect in the AOM 4 are suppressed.

FIGS. 2A, 2C, and 2D are timing charts showing the timing at which laser pulses are emitted from the laser oscillator 3 in the laser processing apparatus of this embodiment. Each timing chart is realized by performing control according to the flowcharts shown in FIGS. FIG. 2B is a timing chart showing the timing at which laser pulses are emitted from the laser oscillator 3 in the laser processing apparatus of the comparative example. The upper part of each figure represents the galvano operation control signal G output by the galvano controller 10, the middle part represents the oscillation command S output by the laser oscillation control part 7, and the lower part represents the laser beam L1 emitted from the laser oscillator 3. represents energy.

The operation and control method of the laser processing apparatus according to this embodiment will be described below with reference to FIGS. FIG. 2(a) shows a case where the value of time T (T1) predicted by the positioning completion prediction unit 12 is shorter than the predetermined time T0, that is, when T1/T0<1. The predetermined time T0 is at least a length longer than the time that should be ensured when the laser oscillator 3 re-emits (re-oscillates) the laser pulse at the shortest time, and is preferably equal to the time that should be ensured. . Assuming that the difference between the time T1 and the predetermined time T0 is t1, the positioning operation completion prediction time A1 is the time t1 earlier than the time when the predetermined time T0 has elapsed from the output start time A0 of the laser pulse for the previous processing.

In this case, as shown in FIG. 2(a), the laser oscillator 3 does not emit a laser pulse at the positioning operation completion prediction point A1, and a predetermined time T0 has elapsed from the output start point A0 of the laser pulse for the previous processing. At the point in time, that is, at the timing delayed by time t1 from the positioning operation completion prediction point A1, the laser pulse for the next processing is emitted. The pulse width of the next laser pulse for processing is the normal pulse width Tp of the laser pulse for processing. In the case of FIG. 2A, by adjusting the output start timing of the laser pulse for the next processing, it is possible to keep the energy amount of the laser pulse incident on the AOM 4 constant per unit time. The laser oscillator 3 is not controlled to emit dummy pulses.

FIG. 2B shows a case where the value of the time T (T2) predicted by the positioning completion prediction unit 12 is longer than the predetermined time T0 and 1<T2/T0<2. That is, the time T2 is longer than 1*T0 by t2 and shorter than 2*T0. The time t2 corresponds to the remainder Tr when the time T predicted by the positioning completion prediction unit 12 is divided by the predetermined time T0. In the case of FIG. 2B, in this comparative example, the laser oscillator 3 first generates a dummy laser pulse with a pulse width Td2 shorter than the normal laser pulse after the time T0 from the output start point B0 of the laser pulse for the previous processing. After that, at the positioning operation completion point B1, a processing laser pulse with a normal pulse width Tp is emitted. The basic hardware configuration (FIG. 1) of the laser processing apparatus for this comparative example is the same as that of this embodiment. In FIG. 2(b), the dummy pulses are shaded, and the same applies to similar drawings below.

Here, the pulse width Td2 of the dummy pulse is the duty of the laser pulse instructed to output to the laser oscillator 3 in the period from the output start time B0 of the laser pulse for the previous processing to the completion time B1 of the positioning operation of the galvanometer scanner 5. is set to be equal to the duty of the laser pulse for processing. In other words, when the duty of the processing laser pulse is D0 (=Tp/T0), the pulse width Td2 of the dummy pulse in the comparative example satisfies Td2/t2=D0.

However, the pulse width of the dummy pulse actually output from the laser oscillator 3 is shorter than the pulse width of the oscillation command S output from the laser oscillation controller 7 . As shown in FIG. 5, which is an enlarged view of a part of FIG. 2B, the laser beam actually starts to be emitted from the laser oscillator after the oscillation command S to the laser oscillator 3 is turned on. This is because there is a certain time delay Δt depending on the specific configuration of the laser oscillator 3 before . Also, if the length of time t2 is extremely short (that is, if Td2<Δt), the oscillation command S will be turned off before the laser oscillator 3 starts emitting dummy pulses, and the dummy pulses will not be generated in the first place. It may not be emitted. As a result, in this comparative example, even if the laser oscillator 3 is caused to output a dummy pulse, the energy of the dummy pulse actually applied to the AOM 4 may be reduced. If the temperature of the AOM 4 drops for this reason, the effect of fluctuations in the thermal lens action on the AOM 4 cannot be sufficiently suppressed, and there is a possibility that the processing quality will deteriorate.

Therefore, in this embodiment, as shown in FIG. 2C, a threshold value Td_min is provided for the pulse width Td3 of the dummy pulse. The time T2 in FIGS. 2(b) and 2(c) is the same. In this embodiment, the pulse width (Td2=t2×D0 in FIG. 2(b)) calculated based on the value of the time T (T2) predicted by the positioning completion prediction unit 12 and the duty D0 to be maintained is When the pulse width Td3 of the dummy pulse is less than the threshold Td_min, control is performed to round up the pulse width Td3 of the dummy pulse to the threshold Td_min. In other words, in this embodiment, when the product (Tr×D0) of the remainder Tr obtained by dividing the time T by the predetermined time T0 and the duty D0 to be maintained is less than the predetermined pulse width threshold value Td_min, The pulse width (second pulse width) of the dummy pulse is set to the threshold Td_min.

It should be noted that the value of the threshold Td_min, which is the lower limit of the pulse width of the dummy pulse, is determined by conducting tests in advance so that the influence of fluctuations in the thermal lens effect on the AOM 4 is within the allowable range. Therefore, the value of the threshold Td_min can be changed according to the specific configuration of the heat capacity of the AOM 4, the laser oscillator 3, and the elements (signal lines, etc.) intervening between the laser oscillation controller 7 and the laser oscillator 3. If Td2<Δt in FIG. 5, the oscillation command S is turned off before the laser oscillator 3 starts emitting dummy pulses, and no dummy pulse is emitted in the first place. is set to be greater than or equal to Δt, which is the time delay of the response of the laser oscillator 3 to the turn-on of the .

In addition, as the pulse width Td3 of the dummy pulse is rounded up to the threshold value Td_min, the output start point B4 of the laser pulse for the next processing is postponed from the positioning operation completion point B1 of the galvano scanner 5 by the time t4. do. In other words, in this embodiment, when the pulse width of the dummy pulse is rounded up to the threshold value Td_min, at time B4 after the time B1 after the time T has elapsed from the output start time B0 of the processing laser pulse, the following The laser oscillator emits a processing laser pulse for irradiating the processing position of . By delaying the output start of the next laser pulse for processing in this way, it is possible to prevent the temperature of the AOM 4 from rising due to the dummy pulse duty becoming larger than D0 due to the pulse width of the dummy pulse being rounded up to Td_min. can.

The time t4 for delaying the emission of the laser pulse for the next processing is given by the following when the time from the output start time B3 of the dummy pulse to the output start time B4 for the next processing laser pulse is t3 (=t2+t4). Preferably, it is a value that satisfies Td3/t3=D0. In other words, the preferred value for t3 is the time Tr_min that satisfies Td_min/Tr_min=D0. In other words, when the time Tr_min that satisfies Td_min/Tr_min=D0 has elapsed from the start of output of the dummy pulse of the second pulse width, the laser oscillator emits a processing laser pulse for irradiating the next processing position. and is suitable. In this case, the ratio (Td3/t3) of the pulse width Td3 of the dummy pulse to the time t3 from the output start time B3 of the dummy pulse to the output start time B4 of the next laser pulse for processing is the duty of the laser pulse for processing. This is because it is equal to D0.

FIG. 2(d) shows a case where the value of time T (T3) predicted by the positioning completion prediction unit 12 is longer than the predetermined time T0 and where n−1<T3/T0<n. However, n is an integer of 2 or more. FIG. 2(d) is a generalization of FIG. 2(c), and FIG. 2(c) corresponds to the case of n=2 in FIG. 2(d).

In this case, the laser oscillator 3 emits a dummy pulse (first dummy pulse) having a normal pulse width Tp each time a predetermined time T0 elapses from the output start point C0 of the previous laser pulse for processing. Repeat n-1 times. Therefore, the duty of the dummy pulse up to the (n-1)th time is the same as the duty D0 of the laser pulse for processing.

Thereafter, as the n-th dummy pulse (second dummy pulse), the laser oscillator 3 is caused to emit a dummy pulse having a pulse width Td4 shorter than the pulse width Tp of the dummy pulses up to the (n−1)th time. In this case, the pulse width (t2′×D0 in FIG. 2(d)) calculated based on the value of the time T (T3) predicted by the positioning completion prediction unit 12 and the duty D0 to be maintained is the threshold value Td_min. In the above case, the pulse width Td4 is set to t2'×D0. On the other hand, when the pulse width (t2′×D0 in FIG. 2D) calculated as described above is less than the threshold Td_min as shown in FIG. Control is performed to round up to . The time t2' corresponds to the remainder Tr obtained by dividing the time T by the predetermined time T0. In other words, when the product (Tr×D0) of the remainder Tr obtained by dividing the time T by the predetermined time T0 and the duty D0 to be maintained is less than the predetermined pulse width threshold value Td_min, the second dummy pulse is generated. is set to the threshold value Td_min.

In addition, as the pulse width Td4 of the dummy pulse is rounded up to the threshold value Td_min, the output start point C4 of the laser pulse for the next processing is postponed from the positioning operation completion point C1 of the galvanometer scanner 5. FIG. In other words, when the pulse width Td4 of the n-th dummy pulse is rounded up to the threshold value Td_min, at time C4 after the time C1 after the time T has passed from the output start time C0 of the processing laser pulse, the following The laser oscillator 3 is caused to emit a processing laser pulse for irradiating a processing position. By delaying the output start of the next laser pulse for processing in this way, it is possible to prevent the temperature of the AOM 4 from rising due to the dummy pulse duty becoming larger than D0 due to the pulse width of the dummy pulse being rounded up to Td_min. can.

The time t4' for delaying the emission of the laser pulse for the next processing is preferably the time from the output start time C3 of the (n-1)th dummy pulse to the output start time C4 of the laser pulse for the next processing. When t3' (=t2'+t4'), it is a value that satisfies Td3/t3'=D0. In other words, the preferred value of t3' is the time Tr_min that satisfies Td_min/Tr_min=D0. In other words, when the time Tr_min that satisfies Td_min/Tr_min=D0 has elapsed from the start of output of the dummy pulse of the second pulse width, the laser oscillator emits a processing laser pulse for irradiating the next processing position. and is suitable. In this case, the ratio (Td4/t3′) of the pulse width Td4 of the dummy pulse to the time t3′ from the output start time C3 of the dummy pulse to the output start time C4 of the next laser pulse for processing is the laser pulse for processing. This is because it is equal to the duty D0 of .

(control flow)
An example of a control method executed by the overall control unit 11 to control the laser processing apparatus according to this embodiment will be described with reference to FIGS. 3 and 4. FIG. Note that each step of the flowchart of FIG. 3 other than S1 and S2 is realized by the laser oscillation control unit 7. A program for executing each step of this flow chart is stored in a storage device provided in the overall control unit 11 . The program is an example of a program for executing the laser processing method according to the present disclosure, and the storage device storing the program is an example of a non-transitory storage medium for executing the laser processing method according to the present disclosure. is. The storage medium can be physically separated from the overall control unit 11, and can be connected to the overall control unit 11 by a means such as a USB connection to allow the overall control unit 11 to read the program. There may be.

As described above, every time the galvanometer operation control signal G is turned on and the galvanometer scanner 5 is driven, the positioning completion prediction unit 12 predicts the positioning operation completion time based on the output timing of the previous processing laser pulse. Calculate the time T (S1, S2 in FIG. 3). Based on the calculated value of time T, the laser oscillation control unit 7 calculates n and Tr (where n is an integer equal to or greater than 0 and 0≦Tr<T0) that satisfies T=n×T0+Tr (FIG. 3). of S3). It can be said that n represents the number of dummy pulses to be emitted from the laser oscillator 3 during the period from when the galvano operation control signal G is turned on until the laser pulse output for the next processing is started. Tr is the remainder when the time T predicted by the positioning completion prediction unit 12 is divided by the predetermined time T0, and is used to determine the pulse width of the last dummy pulse when the dummy pulse is emitted every predetermined time T0. used for

If n calculated in S3 is 0 (S4: Yes in FIG. 3), processing (routine R1 in FIG. 3) is performed to adjust the output timing of the laser pulse for the next processing. In this case, the laser oscillation control unit 7 issues an oscillation command S for causing the laser oscillator 3 to emit the next laser pulse for processing when a predetermined time T0 has elapsed since the output of the previous laser pulse for processing was started. is output (S5 and S6 in FIG. 3). FIG. 2(a) described above corresponds to the case where n calculated in S3 of FIG.

If n calculated in S3 is not 0 (S4: No in FIG. 3), processing for outputting a dummy pulse is performed each time the predetermined time T0 elapses. In this case, when n≧2 (S7: Yes in FIG. 3), a process of outputting a dummy pulse with a normal pulse width each time a predetermined time T0 elapses to count down n (routine R2 in FIG. 3). is done. Specifically, the laser oscillation control unit 7 outputs a dummy pulse with a pulse width Tp when a predetermined time T0 has passed from the timing at which the previous oscillation command S to the laser oscillator 3 was turned on (S8). (S9), decrements n by 1, and returns to S7 (S10). The above-described FIG. 2(d) corresponds to the case of n≧2, and the operation of repeatedly outputting dummy pulses with a normal pulse width Tp in FIG. is.

When n calculated in S3 is 1, or when the routine R2 counts down to n=1 (S7 in FIG. 3: No), as shown in FIG. 4, the n-th dummy pulse (last dummy pulse ) are processed to determine the pulse width and the like.

If the product of Tr calculated in S3 and the duty D0 to be maintained (Tr×D0) is equal to or greater than the pulse width threshold value Td_min (S11: Yes in FIG. 4), the dummy pulse is instructed to the laser oscillator 3. Disadvantages due to the extremely short width do not occur. Therefore, in this case, by performing the process (routine R3 in FIG. 4) of outputting the n-th dummy pulse with the pulse width Td determined by Td=Tr×D0, the duty of the dummy pulse is changed to the duty of the laser pulse for processing. The same value as D0 is maintained, and in synchronization with the completion of the positioning operation of the galvanometer scanner 5, the laser oscillator 3 is caused to start emitting laser pulses for processing.

Specifically, when a predetermined time T0 has elapsed from the timing at which the previous oscillation command S to the laser oscillator 3 was turned on (S12), the laser oscillation control unit 7 controls the pulse width Td=Tr×D0 for the nth time. An oscillation command S is output to output a dummy pulse (S13). Further, the laser oscillation control unit 7 controls the laser oscillator 3 when the time Tr has passed since the previous oscillation command S (oscillation command S for outputting the n-th dummy pulse) to the laser oscillator 3 was turned on (S14 ), and outputs an oscillation command S for causing the laser oscillator 3 to emit a laser pulse for the next processing (S15). That is, in this case, the laser oscillation control unit 7 does not postpone the start of outputting the laser pulse for the next processing after the positioning operation of the galvano scanner 5 is completed. , the laser oscillator 3 is caused to start emitting laser pulses for processing. After that, the process returns to S1 in FIG. 3 and waits until the next galvano operation control signal G is turned on.

If the product (Tr×D0) of Tr calculated in S3 and the duty D0 to be maintained is less than the pulse width threshold value Td_min (S16: Yes in FIG. 4), the pulse width Td temporarily determined by Td=Tr×D0 If the dummy pulse is output at , as described above, the pulse width of the actually output dummy pulse may be short, or the dummy pulse may not actually be output, which may cause fluctuations in the thermal lens effect of the AOM 4. . Therefore, in this case, the pulse width Td is rounded up to the threshold value Td_min to output the n-th dummy pulse (routine R4 in FIG. The duty of the n-th dummy pulse is maintained at the same value as the duty D0 of the laser pulse for processing by performing the process of postponing from the completion of the positioning operation of . 2C and 2D, the dummy pulse is output with a pulse width of Td_min, and the output of the laser pulse for the next processing is started after the completion of the positioning operation of the galvano scanner 5 B1, C1. The actions set at times B4 and C4 are the result of processing routine R4 in FIG.

Specifically, when a predetermined time T0 has elapsed from the timing at which the previous oscillation command S to the laser oscillator 3 was turned on (S17), the laser oscillation control unit 7 controls the pulse width Td=Td_min to generate the n-th dummy signal (S17). An oscillation command S is output to output a pulse (S18). In addition, the laser oscillation control unit 7 sets the time Tr_min to satisfy Td_min/Tr_min=D0 from the timing when the previous oscillation command S (the oscillation command S for outputting the n-th dummy pulse) to the laser oscillator 3 was turned on. (S19), an oscillation command S for causing the laser oscillator 3 to emit a laser pulse for the next processing is output (S20). After that, the process returns to S1 in FIG. 3 and waits until the next galvano operation control signal G is turned on.

When the product of Tr calculated in S3 and the duty D0 to be maintained (Tr×D0) is 0 (S16 in FIG. 4: No), the time T predicted by the positioning completion prediction unit 12 in S2 is less than the predetermined time T0. It is an integer multiple. In this case, processing (routine R5 in FIG. 4) for outputting the laser pulse for the next processing in synchronization with the completion of the positioning operation of the galvanometer scanner 5 is performed without outputting the n-th dummy pulse exceptionally. will be Specifically, the laser oscillation control unit 7 controls that a predetermined time T0 has passed since the previous oscillation command S (oscillation command S for outputting the n-1th dummy pulse) to the laser oscillator 3 was turned on. At that time (S21), an oscillation command S is output to cause the laser oscillator 3 to emit a laser pulse for the next processing (S22). As a result, while maintaining the duty of the dummy pulse constant to the duty D0 of the laser pulse for processing, the irradiation of the laser pulse to the next processing position can be started in synchronization with the completion of the positioning operation of the galvano-scanner 5.

(Other embodiments)
In the above-described embodiment, the galvanometer scanner 5 is exemplified as an example of a deflector that deflects the laser pulse emitted in the processing direction by the acoustooptic device so as to irradiate the workpiece, but other deflectors may be used. good. For example, two sets of AOM 4 and galvanometer scanner 5 are arranged, the laser beam emitted from the laser oscillator 3 is split into two directions by a beam splitter, and two machining positions can be processed simultaneously using the split laser beam. A configuration is conceivable. In this case, when the two galvano-scanners 5 as deflectors are driven, the positioning completion prediction unit 12 calculates the time T required for completing the positioning of the galvano-scanners 5 based on whichever of the positioning completion times is later. Accordingly, the technology of the present disclosure can be applied.

Also, two galvanometer scanners 5 are arranged for one AOM 4, and two machining positions can be processed simultaneously using laser beams deflected in two machining directions from the AOM 4 to the two galvanometer scanners 5. A configuration is conceivable. In this case as well, when two galvano-scanners 5 are driven as deflectors, the positioning completion prediction unit 12 calculates the time T required to complete the positioning of the galvano-scanners 5 based on whichever of the positioning completion times is later. By doing so, the technique of the present disclosure can be applied. As a further modification, two sets of units having two galvanometer scanners 5 are arranged for one AOM 4, and four processing positions can be processed simultaneously. When the galvano-scanner 5 is driven, the positioning completion prediction unit 12 calculates the time T required to complete the positioning of the galvano-scanner 5 based on whichever of the positioning completion times is the latest. can be applied.

1: substrate/2: table/3: laser oscillator/4: acoustooptic device (AOM)/5: deflector (galvano scanner)/6: condenser lens/7D: damper/7: laser oscillation controller/9: AOM control unit/10: Galvano control unit/11: Overall control unit/12: Positioning completion prediction unit

Claims (7)

a laser oscillator that emits a laser pulse;
an acoustooptic device that switches the optical path of the laser pulse emitted from the laser oscillator between a processing direction and a non-processing direction;
a deflector that deflects the laser pulse emitted in the processing direction from the acousto-optic device so as to irradiate the workpiece;
a control means for controlling the laser oscillator;
A positioning operation for positioning the deflector toward a processing position subsequent to the processing position with reference to the output start time of the processing laser pulse for irradiating the processing position of the workpiece by the laser oscillator. prediction means for predicting the time T to completion;
has
The control means is
When the value of the time T is an integer n of 2 or more and n×T0>T>(n−1)×T0 for a predetermined time T0, from the output start time of the laser pulse for processing to the predetermined Every time T0 elapses, the laser oscillator is caused to emit a first dummy pulse with the same pulse width Tp as the processing laser pulse (n−1) times, and then a pulse shorter than the pulse width Tp is emitted. causing the laser oscillator to emit a second dummy pulse with a width Td;
The control means is
When the product (Tr×D0) of the remainder Tr obtained by dividing the time T by the predetermined time T0 and the duty D0 of the pulse width Tp with respect to the predetermined time T0 is less than a predetermined threshold value Td_min, the second setting the pulse width Td2 of the dummy pulse in No. 2 to the threshold value Td_min, and irradiating the next processing position after the time T has elapsed from the output start time of the processing laser pulse. causing the laser oscillator to emit a processing laser pulse for
A laser processing device characterized by: In the laser processing apparatus according to claim 1,
The control means is
When the pulse width Td2 of the second dummy pulse is set to the threshold value Td_min, the next machining position is reached after a time Tr_min that satisfies Td_min/Tr_min=D0 has elapsed from the start of output of the second dummy pulse. causing the laser oscillator to emit a processing laser pulse for irradiating the
A laser processing device characterized by: In the laser processing apparatus according to claim 1 or 2,
The control means is
When the Tr×D0 is equal to or greater than the threshold value Td_min, the pulse width Td of the second dummy pulse is set to the Tr×D0, and the time of the Tr from the output start point of the second dummy pulse is set. After the lapse of time, causing the laser oscillator to emit a processing laser pulse for irradiating the next processing position;
A laser processing device characterized by: In the laser processing apparatus according to any one of claims 1 to 3,
A laser processing apparatus according to claim 1, wherein said predetermined time T0 is a time to be ensured when said laser oscillator re-emits a laser pulse at the shortest time. The optical path of a laser pulse emitted from a laser oscillator is switched between a working direction and a non-working direction by an acoustooptic device, and the laser pulse emitted in the working direction is deflected by a deflector to irradiate a workpiece. In the laser processing method for processing the workpiece,
A positioning operation for positioning the deflector toward a processing position subsequent to the processing position with reference to the output start time of the processing laser pulse for irradiating the processing position of the workpiece by the laser oscillator. Estimate the time T to completion,
When the value of the time T is an integer n of 2 or more and n×T0>T>(n−1)×T0 for a predetermined time T0, from the output start time of the laser pulse for processing to the predetermined Every time T0 elapses, the laser oscillator is caused to emit a first dummy pulse with the same pulse width Tp as the processing laser pulse (n−1) times, and then a pulse shorter than the pulse width Tp is emitted. causing the laser oscillator to emit a second dummy pulse with a width Td;
When the product (Tr×D0) of the remainder Tr obtained by dividing the time T by the predetermined time T0 and the duty D0 of the pulse width Tp with respect to the predetermined time T0 is less than a predetermined threshold value Td_min, the second setting the pulse width Td2 of the dummy pulse in No. 2 to the threshold value Td_min, and irradiating the next processing position after the time T has elapsed from the output start time of the processing laser pulse. causing the laser oscillator to emit a processing laser pulse for
A laser processing method characterized by: The optical path of a laser pulse emitted from a laser oscillator is switched between a working direction and a non-working direction by an acoustooptic device, and the laser pulse emitted in the working direction is deflected by a deflector to irradiate a workpiece. , in a program for a laser processing method for processing the workpiece,
A positioning operation for positioning the deflector toward a processing position subsequent to the processing position with reference to the output start time of the processing laser pulse for irradiating the processing position of the workpiece by the laser oscillator. Estimate the time T to completion,
When the value of the time T is an integer n of 2 or more and n×T0>T>(n−1)×T0 for a predetermined time T0, from the output start time of the laser pulse for processing to the predetermined Every time T0 elapses, the laser oscillator is caused to emit a first dummy pulse with the same pulse width Tp as the processing laser pulse (n−1) times, and then a pulse shorter than the pulse width Tp is emitted. causing the laser oscillator to emit a second dummy pulse with a width Td;
When the product (Tr×D0) of the remainder Tr obtained by dividing the time T by the predetermined time T0 and the duty D0 of the pulse width Tp with respect to the predetermined time T0 is less than a predetermined threshold value Td_min, the second setting the pulse width Td2 of the dummy pulse in No. 2 to the threshold value Td_min, and irradiating the next processing position after the time T has elapsed from the output start time of the processing laser pulse. controlling the laser oscillator to cause the laser oscillator to emit a processing laser pulse for
A program for a laser processing method characterized by: The optical path of a laser pulse emitted from a laser oscillator is switched between a working direction and a non-working direction by an acoustooptic device, and the laser pulse emitted in the working direction is deflected by a deflector to irradiate a workpiece. , in a storage medium storing a program for a laser processing method for processing the workpiece,
A positioning operation for positioning the deflector toward a processing position subsequent to the processing position with reference to the output start time of the processing laser pulse for irradiating the processing position of the workpiece by the laser oscillator. Estimate the time T to completion,
When the value of the time T is an integer n of 2 or more and n×T0>T>(n−1)×T0 for a predetermined time T0, from the output start time of the laser pulse for processing to the predetermined Every time T0 elapses, the laser oscillator is caused to emit a first dummy pulse with the same pulse width Tp as the processing laser pulse (n−1) times, and then a pulse shorter than the pulse width Tp is emitted. causing the laser oscillator to emit a second dummy pulse with a width Td;
When the product (Tr×D0) of the remainder Tr obtained by dividing the time T by the predetermined time T0 and the duty D0 of the pulse width Tp with respect to the predetermined time T0 is less than a predetermined threshold value Td_min, the second setting the pulse width Td2 of the dummy pulse in No. 2 to the threshold value Td_min, and irradiating the next processing position after the time T has elapsed from the output start time of the processing laser pulse. controlling the laser oscillator to cause the laser oscillator to emit a processing laser pulse for
A storage medium storing a program for a laser processing method characterized by:

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