TW201315562A - Laser processing control device and laser processing control method - Google Patents

Abstract

A laser processing control devicecomprises a pulse detection portion for detecting an output timing of a pulse laser outputted by a laser oscillator towards a side of a substrate to be processed, an accumulating portion for accumulating respective energy amount of the pulse laser outputted within a given time and calculating energy accumulated amount, a correction amount calculation portion for calculating a position offset correction amount corresponding to the energy accumulated amount as a correction amount for correcting the irradiating position of the pulse laser to a preferred position when a position offset occurred upon the pulse laser irradiated towards the substrate to be processed, and a control portion for control a processing portion for processing the substrate to be processed by using the pulse laser to correct the irradiating position of the pulse laser based upon the position offset correction amount.

Description

Laser processing control device and laser processing control method

The present invention relates to a laser processing control device and a laser processing control method for controlling an irradiation position of a laser beam to a substrate to be processed.

A laser processing apparatus for performing hole drilling on a printed wiring board is, for example, a Galvano scanner and an f θ lens (f θ lens). In such a laser processing apparatus, a portion of the laser is absorbed by the f θ lens while the laser propagates, and the temperature of the f θ lens rises. Further, as the temperature rises, the refractive index of the lens changes, so that the laser light is refracted by the f θ lens, and the irradiation position of the laser light is changed. Therefore, in general, the temperature of the f θ lens is measured, and the laser irradiation position is corrected by the current scanner according to the temperature.

For example, in the laser processing apparatus of Patent Document 1, a temperature sensor is provided on a side surface portion of the f θ lens, and the laser light irradiation position is corrected by a current scanner based on the measured temperature obtained by the temperature sensor.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2003-290944.

However, in the aforementioned prior art, the measurement position by the temperature sensor is at the end of the f θ lens, so it is difficult to instantaneously and correctly measure the temperature of the central portion of the f θ lens due to the influence of heat conduction or the like. . This is because There is heat conduction in the f θ lens, which causes a time difference in the measured temperature. Therefore, in the correction of the irradiation position of the measured temperature based on the end portion of the f θ lens, there is a problem that the positional deviation is not appropriate.

The present invention has been made in view of the above problems, and an object thereof is to obtain a laser processing control device and a laser processing control method capable of accurately correcting an irradiation position of laser light.

In order to solve the above problems and achieve the object, the present invention provides a pulse detecting unit for detecting an emission timing of a pulse laser emitted from a laser oscillator on a substrate side to be processed, and a multiplication unit. Calculating an energy multiplication amount by multiplying an amount of energy of the pulse laser emitted from the predetermined time within a predetermined time; the correction amount calculation unit calculates a position offset correction amount corresponding to the energy multiplication amount a correction amount for correcting an irradiation position of the pulse laser to a desired position when the pulse laser is irradiated to the substrate to be processed, and a control unit for processing the aforementioned pulse laser processing The processed portion of the substrate to be processed is controlled such that the irradiation position of the pulse laser is corrected in accordance with the positional shift correction amount.

According to the present invention, since the irradiation position of the pulse laser is corrected by the positional shift correction amount corresponding to the energy multiplication amount of the pulse laser emitted within the predetermined time, the effect of accurately correcting the irradiation position of the laser light is achieved. .

Hereinafter, the laser processing of the embodiment of the present invention will be described in detail based on the drawings. Control device and laser processing control method. Further, the present invention is not limited by the embodiment.

(embodiment)

Fig. 1 is a view showing the configuration of a laser processing apparatus according to an embodiment. The laser processing apparatus 100 is a device for performing laser drilling on a substrate (workpiece) 4 belonging to a substrate to be processed by irradiating laser light L (pulse laser light). The laser processing apparatus 100 of the present embodiment performs laser drilling processing on the substrate 4 while correcting the positional shift of the laser light irradiation position due to the temperature rise of the f θ lens 34.

The laser processing apparatus 100 includes a laser oscillator 1, a laser processing unit 3, and a laser processing control device 2 that oscillates laser light L, and the laser processing unit 3 performs a substrate. 4 laser processing. The laser oscillator 1 oscillates the laser light L and sends it to the laser processing unit 3.

The laser processing unit 3 includes a galvano mirror 35X and 35Y, a galvano scanner 36X, 36Y, an f θ lens (condensing lens) 34, an XY table (processing table) 32, and Temperature detecting unit (temperature sensor) 38.

The current scanners 36X and 36Y have a function of changing the orbit of the laser light L to move the irradiation position to the substrate 4, and the laser light L is set in each processing region (a current region (Galvano area)) of the substrate 4 Scan in two dimensions. The current scanners 36X and 36Y rotate the current mirrors 35X and 35Y at a predetermined angle in order to scan the laser light L in the X-Y direction.

The current mirrors 35X and 35Y reflect the laser light L and are deflected toward a predetermined angle. The current mirror 35X biases the laser light L toward the X direction, and the current mirror 35Y The laser light L is deflected in the Y direction.

The f θ lens 34 is a lens having a telecentricity. The f θ lens 34 deflects the laser light L in a direction perpendicular to the main surface of the substrate 4, and condenses (illuminates) the laser light L to the processing position (hole position Hx) of the substrate 4.

The substrate 4 is an object to be processed such as a printed wiring board, and is subjected to drilling processing at a plurality of locations. The substrate 4 is, for example, a three-layer structure of a copper foil (conductor layer), a resin (insulating layer), and a copper foil (conductor layer).

The XY stage 32 mounts the substrate 4 and moves in the XY plane by driving of a motor (not shown). Thereby, the XY table 32 moves the substrate 4 in the in-plane direction.

When the XY table 32 is not moved, the range of the laser processing (scannable area) by the operation of the current (galvano mechanism 36X, 36Y, current mirrors 35X, 35Y) is Current zone (scanning zone). In the laser processing apparatus 100, after the XY table 32 is moved in the XY plane, the laser beams L are scanned two-dimensionally by the current scanners 36X and 36Y. The XY table 32 is sequentially moved so that the center of each current region is directly below the center of the f θ lens 34 (the current of the galvano). The current mechanism operates so that the hole positions Hx set in the current region sequentially become the irradiation positions of the laser light L. The movement of the current section of the XY table 32 and the two-dimensional scanning of the laser light L in the current region by the current mechanism are sequentially performed in the substrate 4. Thereby, all the hole positions Hx in the substrate 4 are laser processed.

The temperature detecting unit 38 is disposed at the end (outer peripheral portion) of the f θ lens 34. The substrate temperature of the f θ lens 34 is measured, and the detection result is transmitted to the position correction amount calculating device 20. The temperature detecting unit 38 may be either a contact type or a non-contact type.

The laser processing control device 2 is connected to the laser oscillator 1 and the laser processing unit 3 (not shown) to control the laser oscillator 1 and the laser processing unit 3. The laser processing control device 2 instructs the laser oscillator 1 and the laser processing unit 3 to perform laser processing conditions set in the machining program when the substrate 4 is laser-processed. Here, the laser processing conditions include a pulse emission timing of the laser light L, a laser light irradiation position (coordinate value on the substrate 4), and the like.

The laser processing control device 2 of the present embodiment includes a position correction amount calculation device 20 and a control unit 30. The position correction amount calculation device 20 is a device that calculates the correction amount (positional deviation correction amount) of the laser light irradiation position based on the energy (for example, the total value) of the laser light L irradiated on the substrate 4 in the most recent predetermined time. The position correction amount calculation device 20 outputs the instruction information (positional deviation correction amount) for the current mechanism to the control unit 30 so that the laser light L is irradiated onto a desired position on the substrate 4.

The control unit 30 controls the operation of the current mechanism or the like according to the machining program, and corrects the operation of the current mechanism based on the instruction information from the position correction amount calculation device 20. The control unit 30 controls and corrects the operation of the current mechanism, thereby controlling and correcting the laser light irradiation position.

In the laser processing apparatus 100, when the laser light L is irradiated to the substrate 4, the temperature of the fθ lens 34 rises. However, when a temperature gradient is generated in the f θ lens 34, the laser light irradiation position on the substrate 4 is deviated from the desired position. Therefore, in the present embodiment, the f θ lens 34 is calculated in advance. The position gradient correction amount corresponding to the temperature gradient or the like is used, and the positional correction amount is used to correct the laser light irradiation position.

The temperature gradient of the f θ lens 34 changes, for example, corresponding to the energy multiplication amount of the laser light L irradiated on the substrate 4 for a predetermined time. Therefore, the relationship between the energy multiplication amount and the positional shift correction amount (correction coefficient, etc.) is derived in advance. Then, at the time of laser processing, the position correction amount calculating means 20 calculates the energy multiplication amount of the laser light L irradiated to the substrate 4 for a predetermined time. Further, the position correction amount calculation means 20 calculates the positional deviation correction amount using the correction coefficient and the calculated energy multiplication amount, and causes the control unit 30 to correct the laser light irradiation position using the positional deviation correction amount.

Further, the positional shift of the irradiation position of the laser light L is caused by a temperature gradient or the like in the f θ lens 34, but the correction coefficient may be set without measuring the temperature gradient in the f θ lens 34. In this case, the actual position offset corresponding to the energy multiplication amount is measured, and the correction coefficient is set based on the measurement result. In other words, the relationship between the energy multiplication amount and the positional deviation amount is derived, and the correction coefficient is set according to the derived relationship.

When the correction coefficient is set based on the temperature gradient in the f θ lens 34, the temperature gradient in the f θ lens 34 is actually measured in the laser processing. Then, the relationship between the temperature gradient and the energy multiplication amount is derived, and the relationship between the temperature gradient and the actual positional offset is derived. Based on the derived results, the relationship between the positional offset and the energy multiplication amount is derived, and the correction coefficient is set based on the derived result.

Further, in the present embodiment, the base temperature of each of the f θ lenses 34 (hereinafter referred to as lens temperature) and the irradiation position of the laser light L (electrical) The combination of the coordinate values in the flow region (hereinafter, referred to as current coordinates) sets the correction coefficient.

The laser processing control device 2 is constituted by a computer or the like, and controls the laser oscillator 1 and the laser processing unit 3 by NC (Numerical Control) control or the like. The laser processing control device 2 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). When the laser processing control device 2 controls the laser oscillator 1 and the laser processing unit 3, the CPU reads the processing program stored in the ROM through the input from the input unit (not shown) by the user, and deploys it on the processing program. Various processing is performed by the program storage area in the RAM. The various materials generated at the time of this processing are temporarily memorized in the data storage area formed in the RAM. Thereby, the laser processing control device 2 controls the laser oscillator 1 and the laser processing unit 3.

Next, the configuration of the position correction amount calculation device 20 will be described. The position correction amount calculation device 20 of the present embodiment selects a correction coefficient used for positional offset correction based on the lens temperature and the current coordinate.

Fig. 2 is a block diagram showing the configuration of a position correction amount calculation means. The position correction amount calculation device 20 includes a pulse detection unit 21, a pulse storage unit 22, a multiplication unit 23, a correction coefficient storage unit 24, a correction amount calculation unit 25, an irradiation position input unit 26, a temperature input unit 27, and an output unit 28. .

The pulse detecting unit 21 detects the laser light L that is incident on the laser processing unit 3 from the laser oscillator 1. The pulse detecting unit 21 causes each of the detected lasers The emission timing (time) of the light L is stored in the pulse storage unit 22.

The pulse memory unit 22 is a memory or the like that memorizes the emission timing of each pulse. The pulse memory unit 22 stores the emission timing of each pulse, for example, between predetermined times (for example, 60 seconds). Then, the pulse memory unit 22 eliminates the memorized emission timing when a predetermined time elapses. For example, the pulse memory unit 22 overwrites the new emission/emission timing with respect to the memory region of the emission timing that has passed through the predetermined time, thereby eliminating the old emission timing.

The multiplying unit 23 calculates the energy multiplication amount of the laser light L emitted from the laser oscillator 1 to the laser processing unit 3 between predetermined times (for example, from 30 seconds ago to the present). The multiplying unit 23 calculates the energy multiplying amount by multiplying the number of pulses of the laser light L emitted from the laser oscillator 1 between the predetermined time and the energy of one unit pulse, for example. The multiplication unit 23 calculates the energy multiplication amount by assuming that the energy of one unit pulse is a constant value.

The correction coefficient storage unit 24 is a memory or the like that memorizes the correction coefficient. The correction coefficient storage unit 24 memorizes the correction coefficient in accordance with the combination of each lens temperature and current coordinates. The irradiation position input unit 26 extracts the current coordinates from the machining program and transmits the current coordinates to the correction amount calculation unit 25. Further, the irradiation position input unit 26 may extract the current coordinate from the irradiation position command (information indicating the position of the irradiation laser light L) transmitted from the laser processing control device 2 to the laser processing unit 3, and may transmit the current coordinate to the correction amount calculation unit. 25. The temperature input unit 27 receives the lens temperature detected by the temperature detecting unit 38 and transmits it to the correction amount calculating unit 25.

The correction amount calculation unit 25 extracts the correction coefficient corresponding to the lens temperature and the current coordinate from the correction coefficient storage unit 24. Correction amount calculation unit 25, the positional offset correction amount is calculated by using the energy multiplication amount calculated by the multiplication unit 23 and the correction coefficient extracted from the correction coefficient storage unit 24. The correction amount calculation unit 25 transmits the calculated positional deviation correction amount to the output unit 28. The output unit 28 transmits the positional shift correction amount to the control unit 30.

Next, the processing procedure of the laser processing by the laser processing apparatus 100 will be described. Fig. 3 is a flow chart showing the processing procedure of the laser processing of the embodiment. When the laser processing apparatus 100 starts laser processing, the laser processing control apparatus 2 controls the laser oscillator 1 and the laser processing section 3 in accordance with the processing program. Thereby, the emission of the laser light L is started (step S10). The self-oscillation oscillator 1 emits laser light L at a timing according to a processing program. Further, the laser processing unit 3 operates the current mechanism, the XY table 32, and the like so as to irradiate the laser light L at a position corresponding to the processing program. Further, the temperature detecting unit 38 detects the side lens temperature.

The pulse detecting unit 21 detects the laser light L emitted from the laser oscillator 1 to the laser processing unit 3, and stores the detected emission timing of each of the laser light L in the pulse memory unit 22 (step S20).

The irradiation position input unit 26 extracts the current coordinates from the machining program or the like and transmits the current coordinates to the correction amount calculation unit 25. Further, the temperature input unit 27 transmits the lens temperature detected by the temperature detecting unit 38 to the correction amount calculating unit 25.

The multiplier 23 calculates an energy multiplying amount of the laser light L emitted from the laser oscillator 1 to the laser processing unit 3 between predetermined times (for example, time Tx to be described later) (step S30). The correction amount calculation unit 25 extracts the correction coefficient corresponding to the lens temperature and the current coordinate from the correction coefficient storage unit 24 (step S40). The correction amount calculation unit 25 is calculated by the multiplication multiplication unit The energy multiplication amount and the correction coefficient extracted from the correction coefficient storage unit 24 calculate the positional deviation correction amount (step S50). The correction amount calculation unit 25 transmits the positional deviation correction amount to the output unit 28.

The output unit 28 transmits the positional shift correction amount to the control unit 30. Thereby, the control unit 30 controls the current scanners 36X and 36Y so as to correct the positional shift of the laser light irradiation position by the positional shift correction amount (step S60). In the laser processing unit 3, the current mirrors 35X and 35Y are rotated by the current scanners 36X and 36Y so that the irradiation position of the laser light L is corrected only by the positional shift correction amount.

Fig. 4 is a view for explaining the control of the current mechanism by the position correction amount calculating means. The position correction amount calculation device 20 detects the laser light L emitted from the laser oscillator 1. Further, the lens temperature detected by the temperature detecting unit 38 is input to the position correction amount calculating device 20.

In the position correction amount calculation device 20, the positional deviation correction amount is calculated based on the energy multiplication amount, the lens temperature, and the current coordinate of the laser light L emitted from the laser oscillator 1 from the predetermined time before the current time. . Then, the position correction amount calculating means 20 corrects the control of the current mirrors 35X, 35Y by the current scanners 36X, 36Y based on the positional shift correction amount.

Here, the relationship between the rising temperature of the f θ lens 34 and the positional shift amount from the target position of the laser light irradiation position will be described. Fig. 5 is a graph showing the relationship between the rising temperature of the f θ lens and the amount of positional shift. In Fig. 5, the horizontal axis represents the rising temperature of the f θ lens 34, and the vertical axis represents the positional shift amount of the laser light irradiation position to the target position. In Figure 5, the characteristic 51 is the measured value, and the characteristic 52 is the analog. (simulation) value.

As the temperature of the f θ lens 34 rises, the positional shift amount of the laser light irradiation position to the target position is larger. Further, since the dynamic characteristics of the current scanners 36X and 36Y are provided, even if the rising temperature is zero ° C, the positional shift amount as shown by the characteristic 51 is not zero. In the present embodiment, the positional deviation correction of the laser beam irradiation position is performed so that the positional shift amount is zero.

The positional shift amount of the laser light irradiation position differs depending on whether or not the laser light L passes through any position on the f θ lens 34 on the substrate 4 (current coordinate). Therefore, in the present embodiment, the positional shift correction amount corresponding to the passing position on the fθ lens 34 of the laser light L is set. In other words, the correction coefficient corresponding to the current coordinate is selected, and the positional deviation correction amount is calculated using the selected correction coefficient.

Fig. 6 is a graph showing the relationship between the passing position on the f θ lens of the laser light and the amount of positional shift correction. In Fig. 6, the horizontal axis is the distance from the center of the f θ lens 34 (hereinafter referred to as the lens center) (the laser light passing position), and the vertical axis is the position shift correction amount. Further, in Fig. 6, the positional shift correction amount when the temperature of the f θ lens 34 rises by 1 °C is shown.

The laser light L scanned by the f θ lens 34 and the current scanners 36X and 36Y is shifted in the telescopic direction due to the temperature rise of the f θ lens 34. When the laser light L is irradiated onto the substrate 4 through the center of the lens, the positional shift amount is substantially zero, and the positional shift correction amount is also substantially zero. Then, as the position larger than the center of the lens shifts, the amount of shift becomes larger, and the amount of positional shift correction also becomes larger.

As described above, the greater the end position shift amount of the f θ lens 34, the larger the end position shift correction amount of the f θ lens 34 is set. In other words, the correction correction coefficient is performed in such a manner that the more the end position shift correction amount of the f θ lens 34 is. As a result, the laser beam L irradiated to the substrate 4 near the center of the f θ lens 34 is subjected to the smaller positional shift correction, and the laser light L irradiated to the substrate 4 near the outer periphery of the f θ lens 34 is performed. The larger the position offset correction. For example, as shown in Fig. 6, the positional offset correction amount is changed in accordance with a linear function. Thereby, the relationship between the distance from the lens center and the positional shift correction amount approximates the linear function, and the irradiation position of the laser light L is corrected.

In the position correction amount calculation device 20, the correction amount calculation unit 25 calculates the position (the distance from the lens center) of the laser light L passing through the f θ lens 34 based on the current coordinates. Then, the correction amount calculation unit 25 extracts the correction coefficient corresponding to the position of the laser light L passing through the f θ lens 34 from the correction coefficient storage unit 24. Thereby, the correction amount calculation unit 25 calculates the positional deviation correction amount using the correction coefficient corresponding to the current coordinate.

Further, the correction system based on the primary function is an example, and other methods (complex approximations such as a quadratic function or the like) may be used for correction. For example, a correction method corresponding to the configuration of the f θ lens 34 and/or other structures (optical characteristics) in the laser processing apparatus 100 is set.

Figure 7 is a diagram for explaining positional offset and positional offset correction. In Fig. 7, the states 40A to 40C of the current region in which the positional shift correction is performed are illustrated. In each of the states 40A to 40C, the relationship between the target irradiation position 41 of the laser light L and the laser light irradiation position 42 is displayed.

State 40A is the state of the current zone immediately after the start of laser processing. Further, the state 40B is a state of the current region when the positional accuracy is deteriorated as the temperature of the f θ lens 34 rises (before the positional shift correction). Further, the state 40C is a state of the current region in which the f θ lens 34 performs positional shift correction when the temperature rises.

As shown in the state 40A, immediately after the start of the laser processing, no positional shift occurs between the target irradiation position 41 of the laser light L and the laser light irradiation position 42. Further, as shown in the state 40B, when the temperature of the f θ lens 34 rises, a positional shift occurs between the target irradiation position 41 of the laser light L and the laser light irradiation position 42. Further, as shown in the state 40C, the positional shift between the target irradiation position 41 of the laser light L and the laser light irradiation position 42 is eliminated by performing the positional shift correction.

Fig. 8 is a view showing the relationship between the actual temperature change of the f θ lens and the temperature detected by the temperature detecting portion. In Fig. 8, the horizontal axis is time (elapsed time from laser processing), and the vertical axis is the temperature of the f θ lens 34. The characteristic 45 shown in Fig. 8 is the actual temperature change of the f θ lens 34, and the characteristic 46 is the temperature change detected by the temperature detecting unit 38.

Before the laser processing is started, the temperature of the f θ lens 34 is a constant value (temperature t1). When laser processing at a predetermined pulse period is started after the elapse of time T1, as indicated by the characteristic 45, the actual temperature of the f θ lens 34 gradually rises, and after a predetermined time elapses, the temperature of the f θ lens 34 becomes a constant value. (Temperature T2). This is because the temperature of the f θ lens 34 is raised when the laser light L passes through the f θ lens 34, but the f θ lens 34 is only when a predetermined time elapses. The temperature returns to the original temperature. In other words, the laser light L rises in temperature from the f θ lens 34 for a predetermined time between the predetermined time. Therefore, after the irradiation of the laser light L, when the irradiation of the laser light L is stopped, after the lapse of the irradiation of the laser light L, the temperature of the f θ lens 34 returns to the original temperature after a predetermined time elapses. In the characteristic 45 shown in Fig. 8, since the irradiation of the laser light L is continued, the f θ lens 34 is raised to the temperature t2, and the temperature t2 is maintained.

Since the temperature detecting unit 38 is disposed at the end of the f θ lens 34, it takes time from the temperature rise of the f θ lens 34 to the temperature detecting unit 38 detecting that the temperature of the f θ lens 34 has risen. Therefore, the actual temperature change (characteristic 45) of the f θ lens 34 is different from the temperature change (characteristic 46) detected by the temperature detecting unit 38. Specifically, as shown by the characteristic 46, after the elapsed time T2 which is later than the time T1, the detected temperature of the f θ lens 34 gradually rises, and after a predetermined time elapses, the temperature of the f θ lens 34 becomes a constant value (temperature T2). Therefore, the temperature detecting portion 38 detects that the f θ lens 34 has become the temperature t2 when the actual temperature of the f θ lens 34 becomes lower than the temperature t2.

Therefore, in the present embodiment, the positional shift correction amount is calculated based on the energy multiplication amount of the laser light L. Then, the correction coefficient corresponding to the detected temperature of the f θ lens 34 is selected as needed. Therefore, the correct positional shift correction amount can be calculated. Further, the correction amount calculation unit 25 may select a correction coefficient corresponding to the energy multiplication amount.

Next, a calculation method of the energy multiplication amount will be described. Fig. 9 is a diagram for explaining a calculation method of the energy multiplication amount. In addition, at the 9th In the figure, a laser pulse of the xth pulse (x is a natural number) is displayed with a laser pulse Px.

The multiplication unit 23 of the position correction amount calculation device 20 calculates the energy multiplication amount of the laser pulse between time (multiplication interval) Tx. In other words, the multiplying unit 23 calculates the moving average of the energy multiplying amount. For example, when the laser pulse Pn of the nth pulse (n is a natural number) is irradiated, the energy of each of the first to nth laser pulses P1 to Pn between the times Tx is multiplied to calculate the energy. Multiply the amount.

Thereafter, when the laser processing is continued, the energy of the laser pulse after the elapse of time Tx is subtracted from the energy multiplication amount, and when a new laser pulse wave is emitted between the times Tx, a new amount is added to the energy multiplication amount. The energy of the laser pulse.

In Fig. 9, the case where the laser pulse of the (n+1)th pulse is emitted, the laser pulse having no elapse of time Tx is displayed. Therefore, energy is not subtracted from the energy multiplication amount. On the other hand, since the (n+1)th pulse laser pulse Pn is emitted between the new times Tx, the energy of the (n+1)th pulse is added to the energy multiplication amount. Thereby, the energy multiplication amount at the time of the laser pulse P(n+1) at which the (n+1)th pulse is emitted is the value of the energy up to the laser pulses P1 to P(n+1). .

Further, in Fig. 9, when the (n+2)th pulse of the laser pulse P(n+2) is emitted, the laser pulse of the time Tx is the laser pulse P1 to P(n-2). ). Therefore, when the (n+2)th pulse of the laser pulse P(n+2) is emitted, the energy of the laser pulses P1 to P(n-2) is subtracted from the energy multiplication amount as the thunder of the elapsed time Tx. Shoot the pulse. On the other hand, the electric pulse P(n+2) of the (n+2)th pulse is emitted between the new time Tx, so the energy is multiplied. The amount plus the energy of the (n+2)th pulse. Thereby, the energy multiplication amount at the time point of the laser pulse P(n+2) at which the (n+2)th pulse is emitted is the laser pulse P(n-1) to P(n+2). The energy is given a total value.

Further, the time Tx belonging to the multiplication section changes due to the structure around the f θ lens 34 and the environment (heat dissipation state). Therefore, the multiplication interval is optimized in accordance with the actual structure and environment around the f θ lens 34.

Further, in the present embodiment, each of the laser pulses in the time Tx is assumed to have the same energy and the energy multiplication amount is calculated, but may be used for the multiplication in the time Tx. Energy changes. In other words, the energy can also be weighted according to the time of each laser pulse.

For example, a laser pulse that is irradiated to the old time zone within the time Tx (which is longer than the elapsed time of the irradiation pulse) causes the influence of the temperature rise of the f θ lens 34 to become small. On the other hand, the laser pulse irradiated in the new time zone within the time Tx (which is shorter than the elapsed time of the irradiation pulse) causes a large influence of the temperature rise of the f θ lens 34. Therefore, for the laser pulse irradiated in the time Tx, the energy corresponding to the elapsed time from the pulse irradiation can also be set. At this time, the laser beam having a shorter elapsed time from the pulse irradiation is set to have a larger energy, and the longer the elapsed pulse from the pulse irradiation is set, the smaller the energy is set. Then, "zero" is set as the energy for the laser pulse from the pulse irradiation elapsed time Tx. Thereby, it is possible to calculate the correct positional shift correction amount corresponding to the temperature gradient of the f θ lens 34.

Next, a processing example of laser processing will be described. When laser processing is performed, for example, irradiation of repetitive laser light and a predetermined waiting state are performed. Figure 10 is a diagram showing the change of the positional offset when the waiting time is set to be short. Fig. 11 is a diagram for explaining a change in the positional shift amount when the waiting time is set to be long.

In Fig. 10 and Fig. 11, the energy of one unit pulse is 10 millijoules (mJ), and the positional shift amount 61, 62 is performed when laser processing is performed at a constant speed of 2000 Hz (Hz). And the f θ lens calculates the temporal variation of the temperature (analog value) 60. The horizontal axis of Figs. 10 and 11 is time, the left side of the vertical axis is the position shift amount, and the right side of the vertical axis is the f θ lens calculation temperature. Further, the positional shift amount at the time of no positional offset correction is the positional shift amount 61, and the positional shift amount at the time of the positional shift correction is the positional shift amount 62. In addition, the multiplication interval (time Tx) of the energy multiplication amount is set to 30 seconds.

In Fig. 10, it is shown that when 5 seconds of laser light irradiation (processing) and a waiting state of 15 seconds are repeated four times, the positional shift amounts 61, 62, and the f θ lens calculate the temperature 60; In Fig. 11, it is shown that when the laser light irradiation for 5 seconds and the waiting state for 30 seconds are repeated four times, the positional shift amounts 61, 62, and the f θ lens calculation temperature 60.

As shown in Fig. 10, when laser light irradiation (processing of 10,000 holes) is performed for 5 seconds at a constant speed of 2000 Hz, the lens 60 calculation temperature 60 and the position shift amount 61 become larger with the irradiation of the laser light L. Further, between the waiting time (15 seconds), the f θ lens calculating temperature 60 and the position shift amount 61 are reduced by a predetermined amount, but the initial value is not returned. Therefore, when the first processing to the fourth processing are performed, the f θ lens calculation temperature 60 and the positional deviation amount 61 after the respective processing are gradually increased.

On the other hand, in the present embodiment, even at a constant speed of 2000 Hz When the laser light irradiation for 5 seconds is performed, the positional shift correction is performed by the amount corresponding to the f θ lens calculation temperature 60, so that the positional shift amount 62 is maintained at a low value steady state. Further, even when the first machining to the fourth machining are performed, the positional shift amount 62 is maintained at a low steady state.

As described above, when the positional shift correction (invalid positional accuracy correction) is not performed for the temperature rise of the f θ lens 34, the amount of temperature shift positional shift with the f θ lens 34 increases. On the other hand, when the positional deviation correction (effectiveness of positional accuracy correction) is satisfied with the temperature rise of the f θ lens 34, the positional shift amount is constant (not increased) even if the temperature of the f θ lens 34 rises.

Further, as shown in Fig. 11, when laser light irradiation (processing of 10,000 holes) is performed for 5 seconds at a constant speed of 2000 Hz, the temperature 60 and the position shift amount 61 are changed with the irradiation of the laser light f θ lens. Big. Further, after the elapse of the waiting time (30 seconds), the f θ lens calculation temperature 60 and the position shift amount 61 are substantially returned to the initial values. Therefore, when the first processing to the fourth processing are performed, the f θ lens calculation temperature 60 and the positional deviation amount 61 after each processing are reached to a predetermined size, and 30 times of the waiting time is passed. After the second, the f θ lens calculation temperature 60 and the position offset amount 61 are substantially returned to the initial values. Even in this case, the amount of positional shift in each processing increases.

On the other hand, in the present embodiment, even when the laser light irradiation for 5 seconds is performed at a constant speed of 2000 Hz, the positional shift correction is performed by the amount corresponding to the f θ lens calculation temperature 60. The 62 series maintains a low value steady state. Moreover, even from the first processing to the fourth time At the time of processing, the positional shift amount 62 is also maintained at a low value steady state.

Thus, when the positional deviation correction is performed for the f θ lens calculation temperature 60, even if the temperature of the f θ lens 34 rises, the positional shift amount is constant (not increased). Further, since the multiplication interval is 30 seconds, the temperature 60 is returned to the normal temperature by the 30 second waiting time f θ lens.

In addition, although the case where the waiting time is set between the laser processing and the laser processing is described here, it is also possible to continuously perform the laser without setting the waiting time between the laser processing and the laser processing. Processing.

Incidentally, the base temperature of the f θ lens 34 varies depending on the installation environment of the laser processing apparatus 100 and the operation state of the laser processing apparatus 100. Therefore, the correction of the offset by the current scanners 36X, 36Y can be performed once at the substrate temperature when the substrate temperature changes to a predetermined value. Thereby, the positional offset is temporarily reset. At this time, the change of the correction coefficient corresponding to the substrate temperature (lens temperature) is unnecessary.

Further, the positional shift correction amount at each laser light irradiation position may be calculated in advance. At this time, the multiplication unit 23 calculates the energy multiplication amount when the laser light irradiation position is irradiated to the laser light irradiation position by calculating the program in advance. Then, the correction amount calculation unit 25 calculates a positional shift correction amount for each of the laser light irradiation positions. The output unit 28 stores the calculated position shift correction amount in a memory unit (not shown) or the like in the laser processing control device 2. When the laser processing is started, the control unit 30 reads out the stored positional shift correction amount, and performs positional shift correction using the positional shift correction amount for each of the laser light irradiation positions.

As described above, according to the embodiment, the energy multiplication amount corresponding to the temperature of the f θ lens 34 is instantaneously calculated. Therefore, it is possible to accurately correct the positional shift of the irradiation position (processing position) of the laser light L based on the energy multiplication amount without causing a time difference. Therefore, it is possible to perform laser processing with good positional accuracy.

(industrial availability)

According to the above, the laser processing control device and the laser processing control method of the present invention are suitable for the drilling process of the substrate to be processed.

1‧‧‧Laser oscillator

2‧‧‧ Laser processing control device

3‧‧ ‧ Laser Processing Department

4‧‧‧Substrate

20‧‧‧ Position correction amount calculation device

21‧‧‧ Pulse Detection Department

22‧‧‧Pulse Memory

23‧‧‧Calculation Department

24‧‧‧Correction coefficient memory

25‧‧‧Measurement Calculation Department

26‧‧‧ Irradiation position input unit

27‧‧‧ Temperature input section

28‧‧‧Output Department

30‧‧‧Control Department

32‧‧‧XY workbench

34‧‧‧f θ lens

35X, 35Y‧‧‧ current mirror

36X, 36Y‧‧‧ Current Scanner

38‧‧‧ Temperature Detection Department

100‧‧‧ Laser processing equipment

L‧‧‧Laser light

P1 to P(n+2)‧‧‧pulse laser

Fig. 1 is a view showing the configuration of a laser processing apparatus according to an embodiment.

Fig. 2 is a block diagram showing the configuration of a position correction amount calculation means.

Fig. 3 is a flow chart showing the processing procedure of the laser processing of the embodiment.

Fig. 4 is a view for explaining the control of the current mechanism by the position correction amount calculating means.

Fig. 5 is a graph showing the relationship between the rising temperature of the f θ lens and the amount of positional shift.

Fig. 6 is a graph showing the relationship between the passing position on the f θ lens of the laser light and the amount of positional shift correction.

Figure 7 is a diagram for explaining positional offset and positional offset correction.

Fig. 8 is a view showing the relationship between the actual temperature change of the f θ lens and the temperature detected by the temperature detecting portion.

Fig. 9 is a diagram for explaining a calculation method of the energy multiplication amount.

Fig. 10 is a view for explaining a change in the positional shift amount when the waiting time is set to be short.

Fig. 11 is a view for explaining a change in the positional shift amount when the waiting time is set to be long.

20‧‧‧ Position correction amount calculation device

21‧‧‧ Pulse Detection Department

22‧‧‧Pulse Memory

23‧‧‧Calculation Department

24‧‧‧Correction coefficient memory

25‧‧‧Measurement Calculation Department

26‧‧‧ Irradiation position input unit

27‧‧‧ Temperature input section

28‧‧‧Output Department

Claims (7)

A laser processing control device includes: a pulse detecting unit configured to detect an emission timing of a laser beam emitted from a laser oscillator on a side of a substrate to be processed; and an multiplication unit that multiplies the foregoing in a predetermined time The energy multiplication amount is calculated by the amount of each energy of the pulse laser; the correction amount calculation unit calculates a positional shift correction amount corresponding to the energy multiplication amount as a pulse laser irradiated on the substrate to be processed When the positional shift occurs, the irradiation position of the pulse laser is corrected to a correction amount of the desired position; and the control unit processes the processed portion of the processed substrate using the pulse laser to correct the positional offset according to the position The amount is corrected in such a manner as to correct the irradiation position of the aforementioned pulsed laser. The laser processing control device according to the first aspect of the invention, wherein the correction amount calculation unit calculates a positional deviation corresponding to a coordinate position of a pulse laser irradiated on the substrate side to be processed in a current region. Shift correction amount. The laser processing control device according to claim 1, wherein the correction amount calculation unit calculates an f θ lens through which the pulse laser transmitted from the laser oscillator to the substrate to be processed passes. The positional offset correction amount corresponding to the substrate temperature. The laser processing control device according to claim 1, wherein the multiplication unit calculates the energy multiplication by multiplying an amount of each energy corresponding to an elapsed time from the emission of the pulse laser. Calculate. The laser processing control device according to claim 1, wherein the multiplying unit calculates the energy multiplying amount by using the amount of each energy of the pulse laser as a constant value. The laser processing control device according to claim 1, wherein the control unit corrects an irradiation position of the pulse laser by controlling a current scanner provided in the processing unit. A laser processing control method includes: an emitting step of a laser oscillator emitting a pulsed laser to a side of a substrate to be processed; and a pulse detecting step for detecting an emission timing of the pulsed laser; Calculating the energy multiplication amount by calculating the amount of each energy of the pulse laser emitted during the predetermined time; the correction amount calculation step is to calculate the position offset correction amount corresponding to the energy multiplication amount as the illumination And correcting the irradiation position of the pulse laser to a correction amount of a desired position when the pulse laser of the substrate to be processed is shifted; and controlling the processing of the substrate to be processed by using the pulse laser The portion is controlled such that the irradiation position of the pulse laser is corrected based on the positional deviation correction amount.