JP2003053563A - Device and method for laser beam machining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for laser beam machining with which the pitch of machined holes is always kept constant. SOLUTION: A numerical controller 6 is set at a simultaneous triaxial control mode and a three dimensional operation including X-axis, Y-axis and an imaginary axis I is synchronously performed. Thus, as to the imaginary axis I, the acceleration and deceleration are performed simultaneously with those for the X-axis and the Y-axis and a starting position and an ending position are moved and attained simultaneously with the X-axis and the Y-axis. In this case, a pulse generator 72 outputs a pulse signal for controlling corresponding to the rotational quantity of an axis driving device 71 of the imaginary axis I to a trigger signal generator 3. The pulse signal for controlling becomes cyclic or a pulse interval inversely proportional to the moving speed of an X-Y stage 4. Thus, machined holes are formed with a constant pitch from the beginning position to the end position on a work W when a laser beam LB emitted from a laser light source 2 is made incident on the work W placed on the X-Y stage 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus and method for performing processing such as drilling on a workpiece using a laser pulse.

[0002]

_2. Description of the Related Art As one of laser processing apparatuses, there is one called a scriber apparatus for making non-through holes in a workpiece by using a laser oscillator such as a CO ₂ laser. In this type of scriber device, a workpiece such as a ceramic plate is linearly moved at high speed by using an XY table, and a periodic pulse laser from a laser oscillator is incident on the workpiece. As a result, non-through holes arranged in a line are formed in the workpiece. Such a row of processed holes is used as perforations and the like for cutting by a hand or the like.

[0003]

However, in the scriber apparatus as described above, near the start point and the end point of drilling,
An unintended through hole may be formed. This is because, due to the driving characteristics of the XY table, the speed decreases at the beginning and end of the movement of the workpiece, so when a laser pulse of a constant frequency is incident on the workpiece, the pitch of the drilled holes is near the start point and end point. It becomes narrower and a through hole is formed in this part.

Here, it is obvious that the formation of the through hole can be avoided by controlling the oscillation timing of the laser oscillator according to the moving speed of the workpiece. However, X
The NC device that operates the Y table and the trigger device that operates the laser oscillation device are flexible in handling changes in specifications.
From the viewpoint of cost reduction and the like, it is usually configured as a combination of independent general-purpose devices, and it is not possible to operate in synchronization with the operation of the XY table even with respect to the generation timing of each laser pulse. .

Therefore, according to the present invention, a general-purpose device can be used as the NC device and the trigger device, and further, it is possible to avoid the formation of the through hole near the start point and the end point of the drilling, that is, the drilled hole. An object of the present invention is to provide a laser processing apparatus and method that can keep the pitch constant.

[0006]

In order to solve the above problems, the laser processing apparatus of the present invention provides a plurality of drive signals for driving a plurality of drive axes up to a target value at the same ratio. A numerical control device having simultaneous multi-axis control means for outputting in a synchronized state, and using a predetermined drive signal of the plurality of drive signals, the workpiece is processed with respect to laser light from a laser light source for processing. And a signal conversion device for generating a pulse signal corresponding to the irradiation timing of the laser light from a virtual drive signal of the plurality of drive signals excluding the predetermined drive signal.

In the above laser processing apparatus, since the signal conversion apparatus generates a pulse signal corresponding to the irradiation timing of the laser light from the virtual drive signal of the plurality of drive signals excluding the predetermined drive signal, By utilizing the surplus virtual drive signal generated by the multi-axis control means, it is possible to generate laser light at a cycle that is inversely proportional to the relative speed of the workpiece, and it is possible to form processing holes at equal intervals in the workpiece. it can. That is, in the simultaneous multi-axis control function of the numerical controller,
Since a plurality of drive signals are generated so as to drive a plurality of drive axes to the target value at the same ratio to each other, for example, when the XY axes are used for relative scanning of the workpiece and the Z axis is redundant, If the pulse signal is obtained by appropriately thinning out the virtual drive signal corresponding to the Z axis, the pulse timing of the pulse signal can be set to be in inverse proportion to the relative speed of the workpiece with respect to the incident position of the laser light. . Therefore,
Such a pulse signal has a wide pulse interval when the relative speed of the workpiece is small and a narrow pulse interval when the relative speed of the workpiece is large. Even if the relative speed of the body is accelerated or decelerated by any characteristic, it is possible to form machined holes at equal intervals in the machined body.

In a preferred aspect of the above apparatus, the relative displacement of the work piece is linear. In this case, the pulse timing of the pulse signal can be set to be exactly proportional to the relative speed of the workpiece.

In another preferred aspect of the above apparatus,
The signal conversion device includes a motor that operates based on the virtual drive signal, and an encoder that detects an operation of a rotation shaft of the motor and generates the pulse signal corresponding to the rotation amount of the motor. In this case, it is possible to easily obtain the highly accurate pulse signal without directly extracting the virtual drive signal generated by the simultaneous multi-axis control means and performing processing such as frequency division.

In a further preferred aspect of the above apparatus, the setting of the target value of the virtual drive axis corresponding to the virtual drive signal is changed by the numerical control apparatus so that the encoder of the signal conversion apparatus can obtain the desired value. The pulse signal is generated. In this case, it is possible to form the processing holes at equal intervals in the workpiece by simply changing the setting of the target value of the virtual drive shaft.

Further, the laser processing method of the present invention uses a step of outputting a plurality of drive signals corresponding to a plurality of drive axes in a synchronized state, and a predetermined drive signal among the plurality of drive signals. Corresponding to the irradiation timing of the laser light from the step of displacing the workpiece relative to the laser light from the laser light source for processing and the virtual drive signal excluding the predetermined drive signal from the plurality of drive signals And a step of generating a pulse signal.

In the above laser processing method, since the pulse signal corresponding to the irradiation timing of the laser beam is generated from the virtual drive signal of the plurality of drive signals excluding the predetermined drive signal, the simultaneous multi-axis control means is used. By utilizing the surplus virtual drive signal that is generated, laser light can be generated at a cycle that is inversely proportional to the relative speed of the workpiece, and it is possible to form equally spaced holes in the workpiece.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining the structure of a laser processing apparatus according to an embodiment of the present invention. This laser processing device outputs a laser light source 2 that generates an infrared laser light LB as processing light for forming a hole, and a trigger signal that causes the laser light source 2 to generate a pulsed laser light LB at a necessary timing. Trigger signal generator 3
And an XY stage 4 that supports a workpiece W that is a workpiece.
And a stage driving device 5 that drives the XY stage 4 to move the work W to an arbitrary position in the XY plane, a numerical control device 6 that outputs a driving signal to the stage driving device 5, and an output from the numerical control device 6. And a signal converter 7 for outputting a pulse signal to be supplied to the trigger signal generator 3 based on the virtual drive signal.

The laser light source 2 is a CO ₂ laser oscillator that emits infrared laser light LB having a wavelength of, for example, about 10 μm in a pulsed manner, and a laser pulse having an upper limit of oscillation frequency of about several kHz is used for the trigger signal generator 3. It is generated at an appropriate timing according to the trigger signal from. The laser light source 2 is not limited to the CO ₂ laser laser, but may be a YA laser.
Various gases such as G laser and solid-state laser can be used.

The trigger signal generating device 3 is a high-speed pulse generating circuit, detects the rising edge of the input control pulse signal, and from this rising time, a trigger pulse having a constant time width necessary for the oscillation operation of the laser light source 2. Is output to the laser light source 2 with a predetermined power.

The XY stage 4 can support the work W below the mirror 21 which reflects the laser light LB from the laser light source 2, and makes the pulsed laser light LB from the laser light source 2 incident on the work W. At this time, the workpiece W can be moved to any position in the XY plane. The work W is a ceramic plate, and the laser light L
By B, the processed hole row to be penetrated is formed at a minimum pitch of about 150 μm.

The stage driving device 5 constitutes a scanning means together with the XY stage 4 and moves the XY stage 4 to an arbitrary position in the XY plane based on an instruction from the numerical control device 6. For this reason, in the stage drive device 5, axis drive devices 51 and 52 for displacing the XY stage 4 in the two XY directions are incorporated. This shaft drive 5
Reference numerals 1 and 52 each include a pulse motor and a rotation amount detection encoder, and feedback control of the drive position of the XY stage 4 is possible.

The numerical control device 6 uses the code information composed of numerical values and symbols to transmit XY via the stage drive device 5.
It has a function for automatically controlling the movement operation of the stage 4, and while receiving a feedback signal from the shaft driving devices 51 and 52 of the stage driving device 5, sends a driving signal to these shaft driving devices 51 and 52. At this time, the biaxial drive devices 51 and 52 are designed to operate synchronously toward the final target rotation amount.

The signal conversion device 7 operates on the basis of a virtual drive signal from the numerical control device 6 (specifically, an unused drive signal for the Z axis is used), and an axis drive device 71. And a pulse generator 72 connected to the rotating shaft of the shaft driving device 71.

The shaft driving device 71 has a pulse motor 71a and a rotation amount detecting encoder 71b, and operates based on a virtual driving signal from the numerical controller 6.
That is, the numerical control device 6 includes the rotation amount detection encoder 7
The drive signal is transmitted to the pulse motor 71a while receiving the feedback signal regarding the rotation amount from 1b. At this time, the pulse motor 71a is controlled by the numerical control device 6 under the simultaneous three-axis control to reach the final target rotation amount.
It is designed to rotate at the same ratio as these in synchronism with 1, 52.

The pulse generator 72 is an encoder in which a photocoupler and an interrupter are combined, and has basically the same structure as the rotation amount detection encoder 71b, and a pulse signal corresponding to the rotation angle of the pulse motor 71a. Is to occur. That is, the pulse generator 72
Is a control pulse signal to be input to the trigger signal generator 3, that is, a pulse corresponding to the operation timing of the laser light source 2 in accordance with the rotation of the pulse motor 71a that operates based on the virtual drive signal from the numerical controller 6. Generate a signal.

The operation of the laser processing apparatus shown in FIG. 1 will be described below. First, in the numerical control device 6, the XY stage 4
Axis drive devices 51, 52 corresponding to the start and end points of the movement of the
Information such as the driving amount of the pulse motor 71a is appropriately input, and the target value of the rotational driving amount of the pulse motor 71a corresponding to the virtual driving axis is set. That is, an axis drive device 51 corresponding to the X axis,
The axis drive device 52 corresponding to the Y-axis and the axis drive device 71 corresponding to the virtual axis I (specifically, the Z-axis) are collectively treated as a three-dimensional virtual drive device and corresponding to the three-dimensional movement. The information necessary for the movement command to be input is input to the numerical controller 6.
Further, the numerical controller 6 is set to the simultaneous three-axis control mode so that the three-dimensional operation including the X axis, the Y axis, and the virtual axis I can be performed in synchronization. As a result, also with respect to the virtual axis I, acceleration / deceleration is performed at the same time as the X axis and the Y axis, and the start point and the end point also move and arrive at the same time as the X axis and the Y axis. Next, the numerical control device 6 causes the respective axis drive devices 51, 52, 71 to actually output a signal corresponding to the movement command.
This allows the XY stage 4 to move to an appropriate coordinate vector (Δ
Move linearly by X1, ΔY1). At this time, the pulse generator 72 outputs a control pulse signal corresponding to the rotation amount of the axis drive device 71 of the virtual axis I to the trigger signal generation device 3. This control pulse signal is synchronized with the movement of the virtual axis I, that is, the movement of the X axis and the Y axis,
The period or pulse interval is inversely proportional to the moving speed of the XY stage 4. Therefore, when the laser light LB from the laser light source 2 enters the work W on the XY stage 4,
The movement speed of the XY stage 4 and the pulse interval of the laser light LB cancel each other out, and work holes are formed on the work W at equal intervals from the start point to the end point.

FIG. 2 is a block diagram for explaining the structure of the numerical controller 6. The numerical control device 6 is composed of an electric circuit similar to a computer, and includes a central processing control unit 61, an input unit 62, a storage device 63, an operation mode setting unit 64, a drive device interface 65, and an auxiliary operation device interface 66. . The central processing control unit 61, the operation mode setting unit 64, and the drive device interface 65 are
Simultaneous multi-axis control means is configured.

The central processing control unit 61 operates based on an instruction from the input unit 62, data stored in the storage device 63, and the like, and communicates with the drive device interface 65 and the auxiliary operation device interface 66 while these interfaces 6 are being operated.
It is possible to operate the shaft drive devices 51, 52, 71 via 5, 66 by an appropriate amount.

The input section 62 is for inputting information necessary for the operation of the numerical control device 6, and is for centrally processing data such as code information which is a series of instructions for operating the central processing control section 61. It is transmitted to the control unit 61 or an appropriate command signal is input to the operation mode setting unit 64.

The operation mode setting unit 64 sets the operation mode of the central processing control unit 61, and can operate the numerical control device 6 in the simultaneous 3-axis control mode or the non-simultaneous 3-axis control mode. In simultaneous 3 axis control mode, X axis,
The Y-axis and the three axes including the virtual axis I are operated synchronously, and in the non-simultaneous three-axis control mode, the three axes are not operated synchronously. For example, in the simultaneous 3-axis control mode, the movement amount of each axis X, Y, I is determined according to the content of the movement command set as the code information. Specifically, based on the target moving amount and moving speed set in the three axis directions of X, Y, and I, the initial acceleration in the X, Y, and I directions of each axis, and the moving speed at the stable time (feed rate). ), And the final deceleration.

The drive device interface 65 is for operating each of the shaft drive devices 51, 52, 71 in a target state, and is a feedback regarding the rotation amount transmitted from each of the shaft drive devices 51, 52, 71. A drive signal is transmitted to each axis drive device 51, 52, 71 while monitoring the signal. In controlling the drive amount of each axis drive device 51, 52, 71, not only a classical control method such as PID but also various control methods based on various control theories can be used.

The auxiliary operating device interface 66 is XY
This is a part that generates signals necessary for the operation of devices other than the stage 4 and the signal conversion device 7. However, in the case of the present embodiment, since the control target of the numerical control device 6 is limited to the XY stage 4 and the signal conversion device 7, the auxiliary operation device interface 66 is not operated.

Here, the setting of the target value of the movement amount in the I-axis direction when the XY stage 4 is linearly moved will be described. Set the amount of movement in the X-axis direction to Xa [m
m], the movement amount in the Y-axis direction is set to Ya [mm], and the pitch of the machined holes is Pa [μm]. in this case,
The distance L [mm] from the start point to the end point of the processed hole is given by L = √ (Xa ² + Ya ² ), and the pulse signal to be supplied from the signal converter 7 to the trigger signal generator 3 during this distance L. The number of pulses N included in is N = L × 1000 / Pa = (1 / Pa) × √ (Xa ² + Ya
² ) × 1000. Therefore, assuming that the number of pulses to be generated per rotation of the virtual axis I is n [1 / rev], the moving amount Ia [mm] of the virtual axis I is calculated by using the constant α: Ia = αN / n = (α / Pa ・ n) × √ (Xa ² + Ya ² )
It becomes × 1000. That is, the target movement amount Ia can be uniquely given from Xa, Ya, Pa, and n. Here, the number of pulses for one rotation is n, the number of openings formed in the photo interrupter of the rotation amount detection encoder 71b, and the numerical controller 6
It depends on the setting of the electronic gear related to the virtual axis I and can be appropriately set in advance.

On the other hand, if Ia becomes larger than L to some extent, the target moving speed instructed in the XY plane may not be obtained, and conversely, if L becomes much larger than Ia,
The required pulse cannot be obtained. For this reason, it is desirable to change the setting of the number of pulses per rotation of the virtual axis I according to the change of the range of the pitch Pa of the machined hole by a method such as changing the setting of the electronic gear of the numerical control device 6. .

FIG. 3 is a graph for explaining formation of processed holes by the laser processing apparatus of FIG. Figure 3 (a)
Indicates the moving speed of the XY stage 4 in the X-axis direction, and FIG.
3B shows the moving speed of the XY stage 4 in the Y-axis direction, FIG. 3C shows the apparent moving speed of the virtual axis I, and FIG. 3D shows the rotation of the signal conversion device 7. The pulse train output from the quantity detection encoder 71b is conceptually shown.

As shown in FIGS. 3 (a) to 3 (c), simultaneous 3
In the axis control mode, the moving speed of each axis X, Y, I is
It is maintained at a constant ratio, and when acceleration is started in the X, Y, and I directions at the same time, and when the final target point is reached, it is not possible to see from the graph, but movements are simultaneously made for the X, Y, and I axes. Stop.

As shown in FIG. 3D, the intervals of the pulse trains output from the rotation amount detecting encoder 71b are inversely proportional to the moving speeds in the X, Y and I directions of the respective axes. That is, the intervals of the pulse trains gradually decrease as the moving speeds in the X, Y, and I directions increase, and the intervals of the X, Y, and I axes increase.
When the moving speed in the direction reaches the constant speed range, the interval becomes constant. As a result, the spots of the laser light LB from the laser light source 2 are incident on the work W on the XY stage 4 at regular intervals, and the processed holes that do not penetrate through the work W are formed at equal intervals.

FIG. 4 is a diagram for explaining a pattern of processed holes formed on the work W. When the laser processing apparatus according to the present embodiment is used, the distance between the processing holes LH is constant even at the start point and the end point of the linearly extending processing hole row.

FIG. 5 shows, as a comparative example, a machined hole L formed on a work W when a conventional laser machining apparatus is used.
It is a figure explaining the pattern of H. In this case, the interval between the machined holes LH is narrow in the initial acceleration stage and the final deceleration stage. This is because when the numerical control device 6 outputs a command signal to the trigger signal generation device 3 as a processing command, it cannot exactly correspond to the driving speed of the XY stage 4, so that the trigger signals are generated at regular intervals. This means that the speed decreases at the start point and the end point of processing, and the interval between the processing holes LH becomes narrower. If the distance between the processed holes LH is narrowed in this way, unnecessary heat input may occur, and an unintended through hole may be formed.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments.
For example, the signal conversion device 7 does not need to be configured by the shaft driving device 71 and the pulse generator 72, and the numerical control device 6
It is also possible to directly generate a pulse signal corresponding to the operation timing of the laser light source 2 by using the drive signal output for driving the virtual axis I from.

Further, in the above embodiment, the irradiation timing of the laser beam LB onto the work W is adjusted by controlling the interval of the pulse trains transmitted to the trigger signal generator 3, but the laser light source 2 is continuously oscillated. It can also be a laser of the mold. In this case, a shutter is provided between the laser light source 2 and the work W, and this shutter is operated according to the pulse train as shown in FIG. With this, the work W
The processed holes LH formed above can be evenly spaced.

In the above embodiment, the XY stage 4 is moved two-dimensionally with the X and Y axes as the actual drive axes, but the stage is three-dimensionally moved with the X, Y and Z axes as the actual drive axes. It can also be moved. In this case, operate the numerical control device 6 in the control mode of four or more simultaneous axes,
By setting the surplus axes other than the X, Y, and Z axes as the virtual axis I, it is possible to form machined holes at even intervals even on the workpiece W that moves three-dimensionally.

[0039]

As is apparent from the above description, according to the laser processing device of the present invention, the signal conversion device causes the laser beam to be removed from the virtual drive signal excluding the predetermined drive signal from the plurality of drive signals. Since the pulse signal corresponding to the light irradiation timing is generated, the surplus virtual drive signal generated by the simultaneous multi-axis control means can be used to generate the laser light in a cycle inversely proportional to the relative speed of the workpiece. Further, it is possible to form machined holes at equal intervals in the object to be machined.

Also according to the laser processing method of the present invention, a pulse signal corresponding to the irradiation timing of the laser light is generated from the virtual drive signal of the plurality of drive signals excluding the predetermined drive signal. By utilizing the surplus virtual drive signal generated by the multi-axis control means, it is possible to generate laser light at a cycle that is inversely proportional to the relative speed of the workpiece, and it is possible to form processing holes at equal intervals in the workpiece. it can.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a structure of a laser processing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a structure of a numerical control device.

3 (a), (b), and (c) are graphs for explaining formation of machined holes by the laser machining apparatus of FIG. 1, and (d) is a graph transmitted to a trigger signal generator. It is a figure explaining the space | interval of the pulse train.

FIG. 4 is a diagram illustrating formation of a processed hole by the laser processing method according to the embodiment.

FIG. 5 is a diagram illustrating formation of a processed hole by a conventional laser processing method.

[Explanation of symbols]

2 laser light source 3 Trigger signal generator 4 XY stage 5 Stage drive 6 Numerical control device 7 Signal converter 71 axis drive 71a pulse motor 71b Rotation amount detection encoder 72 pulse generator LB laser light LH processed hole

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Claims (5)

[Claims] 1. A numerical controller having simultaneous multi-axis control means for outputting a plurality of drive signals for respectively driving a plurality of drive axes up to a target value at the same ratio, in a synchronized state. A scanning unit that relatively displaces the workpiece with respect to the laser light from the laser light source for processing by using a predetermined drive signal of the plurality of drive signals; A laser processing device comprising: a signal conversion device that generates a pulse signal corresponding to the irradiation timing of the laser light from a virtual drive signal excluding a drive signal. 2. The laser processing apparatus according to claim 1, wherein the relative displacement of the workpiece is linear. 3. The signal conversion device includes: a motor that operates based on the virtual drive signal; and an encoder that detects the operation of a rotation shaft of the motor and generates the pulse signal corresponding to the rotation amount of the motor. The laser processing apparatus according to claim 1, further comprising: 4. The necessary pulse signal is generated from the encoder of the signal conversion device by changing the setting of the target value of the virtual drive axis corresponding to the virtual drive signal in the numerical control device. The laser processing apparatus according to claim 3. 5. A laser for processing a workpiece using a step of outputting a plurality of drive signals corresponding to a plurality of drive shafts in a synchronized state, and using a predetermined drive signal among the plurality of drive signals. Displacement relative to the laser light from the light source, and generating a pulse signal corresponding to the irradiation timing of the laser light from a virtual drive signal excluding the predetermined drive signal from the plurality of drive signals A laser processing method comprising: