JP2007050414A - Laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining apparatus that can use a laser beam without bisecting but with only one axis. <P>SOLUTION: The laser beam machining apparatus is equipped with a laser oscillator, an optical splitter for splitting a laser beam emitted from the laser oscillator, and a first and a second positioning means by which the split laser beam is each made incident and positioned respectively to a machining position on a workpiece. In this apparatus, between the laser oscillator and the optical splitter, there is installed a reflection mirror moving section for putting in and out, in the travelling direction of the laser beam, an optical path reaching either the first positioning means composed of a plurality of reflection mirrors or the second positioning means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser processing apparatus that can divide a laser beam from a laser oscillator and simultaneously perform a plurality of processes with a single laser oscillator.

  As an example of a laser processing apparatus that divides a laser beam from a conventional laser oscillator into a plurality of parts and performs a plurality of processings simultaneously, a description will be given below using a printed circuit board drilling laser processing apparatus (see, for example, Patent Document 1).

  In FIG. 5, a laser beam 2 emitted from a laser oscillator 1 is changed in direction by a reflecting mirror 3a and branched into two by a beam splitter (branching means) 10, and XY meter galvanometers 4 and 5 and respective galvanometer mirrors 4a. 5a and the fθ lens 6 are guided to two sets of laser irradiation parts A and B.

  The optical path lengths at which the laser beams 2a and 2b branched by the beam splitter 10 reach the focusing points by the fθ lenses 6 of the laser irradiation portions A and B are set to be the same distance.

  That is, the laser beam 2a branched by the beam splitter 10 is reflected by the reflecting mirrors 3b and 3c and incident on the galvano mirror 4a, and the laser beam 2b branched by the beam splitter 10 is reflected by the reflecting mirrors 3d, 3e and 3f. The optical path length incident on the galvano mirror 4a is the same length.

  By matching the optical path lengths in this way, the focused states of the laser beams 2a and 2b in the laser irradiation portions A and B are the same, and simultaneous processing on the two substrates 17 can be performed with high accuracy.

  The substrate 17 to be processed by the laser irradiation structure is held at a predetermined position on the XY table 19. Since the processing range of the substrate 17 is wider than the scanning area of each laser irradiation part A, B, the processing range is divided into a plurality of parts as shown by the broken lines, and one processing range is obtained by scanning with each laser irradiation part A, B. When the processing is completed, the next processing range is moved below the laser irradiation units A and B by the XY table 19.

  In addition, the internal structure of the laser irradiation parts A and B in this structure is shown in FIG. As shown in the figure, a discarded pulse receiver (laser beam shielding means) 20 is provided on the support frame portion of the lens body constituting the fθ lens 6.

The laser irradiation units A and B on the side where the processing has been completed first rotate the galvanometer mirrors 4 a and 5 a by the sweep operation of the galvanometers 4 and 5 to irradiate the discarded pulse receiver 20 with the laser beam 2. When the laser irradiation is stopped, the laser beam 2 is quickly shielded, so there is no unnecessary laser irradiation, and harmful effects due to unnecessary laser irradiation are prevented.
JP 11-192571 A

  In the configuration in which the laser beam is divided as in the above-described conventional configuration, the laser beam is divided even when processing only one side, and only a laser beam having an intensity half that of the output of the laser oscillator is used. There was a restriction that it was not possible.

  Therefore, in processing that requires high output laser intensity, the laser oscillator conditions must be changed, or if the laser intensity is still insufficient, another laser processing apparatus must be used, which is complicated. there were.

  In addition, when the laser intensity is increased, optical parts that reflect the laser beam are often coated to increase the reflectivity in accordance with the wavelength of the laser beam. come.

  If the optical parts are damaged in this way, the intensity of the laser beam on the workpiece decreases, and the desired processing result cannot be obtained. Therefore, the optical parts must be replaced, and the laser There was also a problem that it took time to reset the optical parts such as position adjustment with the light, and the line stopped during that time, the cost of optical parts, and the work cost.

  In view of the above problems, the present invention provides a laser processing apparatus that can double the intensity of a laser beam.

  In order to solve the above problems, a laser processing apparatus of the present invention includes a laser oscillator, splitting optical means for splitting the laser light emitted from the laser oscillator, and the split laser light incident on the workpiece. The first and second positioning means are respectively positioned to the machining positions, and a moving part is provided for holding the divided optical means and for taking the divided optical means into and out of the optical path of the laser beam. .

  The laser processing apparatus of the present invention also includes a laser oscillator, splitting optical means for splitting the laser light emitted from the laser oscillator, and positioning each of the split laser light to the processing position on the workpiece. First and second positioning means, and between the laser oscillator and the splitting optical means, reach either one of the first positioning means and the second positioning means including a plurality of reflecting mirrors. A reflecting mirror moving unit is provided for taking the optical path in and out of the traveling direction of the laser beam.

  With this configuration, in any of the above configurations, the laser beam can be divided and used when divided and used, and when the intensity of the laser beam is required, the laser beam is incident on one positioning means without being divided. Thus, the intensity of the laser beam can be doubled compared to the conventional one.

  As described above, according to the present invention, a laser beam that is not divided on at least one laser beam side of a laser processing apparatus that divides a laser beam into a plurality of laser beams can be used, so that a laser that splits a conventional laser beam into a plurality of laser beams. Processing that requires the intensity of laser light that could not be performed by the processing apparatus can be performed.

(Embodiment 1)
FIG. 1 is a diagram showing a part of an optical system arrangement of a laser processing apparatus (for example, a UV laser processing apparatus) in the first embodiment. FIG. 1A is a layout diagram that does not include the first and second positioning means, and FIG. 1B is a layout diagram that includes the first and second positioning means.

In each of two-axis machining that divides the laser beam to make the laser axis two axes and one-axis machining that does not divide the laser beam and makes the laser axis one axis, a reflecting mirror moving part is configured. The arrangement of vent mirrors (hereinafter abbreviated as mirrors) 113 to 115 is different. In FIG. 1A, the arrangement of the mirrors 113 to 115 is indicated by a solid line and a dotted line, respectively, in each case of biaxial machining and uniaxial machining.
First, the arrangement of the optical system at the time of biaxial machining in which the arrangement of the mirrors 113 to 115 is indicated by solid lines will be described. Laser light emitted from a laser oscillator 101 (for example, a UV laser oscillator using a YAG laser) is split through a mirror 102, a mirror 103, a set of two collimator lenses 104, a mask 105, and a half-wave plate 106. The beam is split by a beam splitter 107 as an optical means. One of the divided laser beams is guided to the mirror 110 through the mirror 108 and the mirror 109. The remaining laser light is guided to the mirror 112 through the mirror 111.
The mirrors 113 to 115 that constitute the reflecting mirror moving unit have a mechanism that moves in a direction perpendicular to the optical axis during biaxial processing, and the mirrors 113 to 115 are all off the optical path during normal biaxial processing. .
As shown in FIG. 1B, the optical path is lowered by the bend mirrors 110 and 112, and the Z1 axis and Z2 axis units 121 and 122 (first and second positioning units) each incorporating the galvano mirror and the fθ lens are provided. Then, it is guided to the processing table 123 via the means.
Next, an operation at the time of uniaxial machining in which the arrangement of the mirrors 113 to 115 is indicated by dotted lines will be described. An air cylinder (not shown) is provided so that the mirrors 113 to 115 enter and exit at right angles to the optical axis of the laser beam. When machining is performed such that the intensity is insufficient due to the bifurcated laser light, when the “single axis machining” menu is selected on the operation screen (machining device touch panel) of the machining device, the air is commanded by a control unit (not shown). The cylinder is operated, and the base on which the mirrors 113 and 114 are fixed slides so that the mirror 113 is inserted into the optical path on the side closer to the laser oscillator 101 than the half-wave plate 106. At the same time, the pedestal to which the mirror 115 is fixed is slid by another air cylinder, and the mirror 115 enters one of the two optical paths guided by the beam splitter 107 during biaxial machining.

  At this time, the laser beam reflected by the mirror 113 in the perpendicular direction is reflected by the mirror 114 in the perpendicular direction. There is a mirror 115 on the extension line, and when the laser beam is reflected by the mirror 115, it is directly guided to either the Z1 axis below the mirror 110 or the Z2 axis below the mirror 112. As a result, the optical path does not pass through the beam splitter 107, so that processing can be performed using laser light that is not divided into two on either the Z1 axis or the Z2 axis.

  When measuring the machining point output, both the measured value and the internal power monitor value of the laser oscillator (oscillator output) remain in the history. At this time, the ratio of the machining point output to the oscillator output is calculated and remains in the history at the same time. When this ratio is reduced by 10% or more from a certain point in the past, “optical component is dirty or damaged → mirror position movement” is displayed on the processing device touch panel. A certain point in the past means a point in time when the processing point output shows a normal output at the beginning of delivery of the processing apparatus or cleaning / replacement of optical parts.

  When the oscillator output is reduced by 10% or more, “laser oscillator output reduced” is displayed on the processing device touch panel. In addition, when the laser oscillator output and the processing point output decrease without the mask are not recognized, and the processing point output when passing through the mask is more than 10% lower than the past time point, the “relative positional deviation between the optical axis and the mask” Is displayed on the processing device touch panel.

  In the laser oscillator having no internal power monitoring function as described above for monitoring the laser oscillator output, a power sensor is installed in the vicinity of the beam exit. The power sensor is fixed to the air cylinder, and moves to the optical path to receive the laser beam when measuring the oscillator output. After the measurement is completed, the power sensor is removed from the optical path by the air cylinder. Thereafter, the machining point output without the mask is measured, and the ratio of the machining point output to the oscillator output is calculated. When this ratio has decreased by 10% or more from a certain point in the past, “dirt or damage on optical component → mirror position movement” is displayed.

  During program operation on the processing device, the processing point output when passing through the mask used for processing and the processing point output without mask are automatically about every 2 hours (when processing of the workpiece being processed is completed). Measured and if a decrease of 10% or more is detected in any of the outputs or ratios mentioned above, “Processing point output has decreased. Processing of the remaining workpiece will be stopped.” "Is displayed on the screen and the execution of the machining program is automatically stopped. The remaining unprocessed workpiece is not processed.

FIG. 2A is a diagram illustrating rotation of the main body mirror 116 of the mirrors 113 to 115 in the laser processing apparatus in the first embodiment, and FIG. 2B is a light receiving position in the laser processing apparatus in the first embodiment. It is a figure which shows a change means. The mirror main body 116 is fixed to a ring 117 with two male screws facing each other. The mirror holder 118 has eight female screws (equally spaced on the circumference) into which the male screws for fixing the mirror are screwed, and can be fixed at eight angles. A stage 119 is provided on the pedestal portion of the mirror holder 118 and can be moved in the vertical direction. The optical axis is initially aligned at the center of the mirror, and then the mirror position is shifted by the stage 119.
The holder of the beam splitter 107 is provided with a ring-shaped member having a hollow portion where the laser beam of the beam splitter 107 can be branched as a center of the mat. Use the adjustment knob 120 to finely adjust the angle of the stage so that the optical axis does not deviate from the center of the mat fixed to the holder of the beam splitter 107 even if the stage is moved within the range where the optical axis does not deviate from the mirror. .

  A linear guide with a servo motor may be incorporated instead of the stage. When "Optical parts are dirty or damaged-> Move mirror position" is displayed on the processing device touch panel, the mirror 113 is slid 3mm above the stage (in the range where the optical path cannot be removed), and the processing point output without mask is measured. To do. If the ratio to the oscillator output at this time does not change, the mirror is not soiled or damaged. However, if it shows a recovery tendency, dirt or damage exists at the light receiving position before the mirror movement.

In this case, the mirror surface (reflection surface) is first cleaned, the mirror 113 is returned to the original position by the stage, and the processing point output without the mask is measured again. If the ratio to the oscillator output at this time has recovered to the same level as when the mirror is moved, the dirt on the mirror has been removed.
There is damage that cannot be removed by cleaning if it is not much different from before cleaning. In this case, the attachment angle is shifted by 45 °, the damaged part is removed from the optical axis, the machining point output without the mask is measured, and it is confirmed that the ratio is equivalent to the ratio of the oscillator output when the mirror is moved.

For the optical components that can shift the position without changing the optical axis, the above work is performed in order from the optical components with high possibility of damage (those with a narrow irradiation beam diameter and low light intensity), and the processing point output is Continue until the original level is restored. If the ratio to the oscillator output is within 1% compared to a certain point in the past, the screen will display “Output has recovered. Workpiece processing can be resumed.”
If the output is not fully recovered by continuing to the end, there is dirt or damage on other optical components without the shift mechanism. In this case, a message “Other optical components are dirty or damaged” and a list of possible optical components are displayed on the processing device touch panel. Since these optical components cannot be used with their positions shifted, if the machining point output does not recover even after cleaning, they must be replaced.
If the light receiving positions are damaged at all eight fixed angles of the mirror, the eight light receiving positions that are not damaged can be secured again by sliding the entire holder upward 3 mm (in a range where the optical path cannot be removed).

  If the servomotor can rotate the mirror at an arbitrary angle, the number of places where light can be received further increases. (Refer to FIG. 3.) Each mirror, which is a replacement part, is assigned a number for identification. Called as 1. Numerical values are input to “diameter (vertical) direction shift amount” and “circumferential (angle) direction shift amount” in “mirror No. 1 movement amount setting” displayed on the processing apparatus touch panel. Since the beam diameter is about 1 mm, it is sufficient if the amount of shift in the diameter (up and down) direction of the mirror is 3 mm. The amount of shift is approximately 3 times the beam diameter. The radial shift is performed within a range where the light receiving position is 80% of the effective diameter of the mirror.

Since the mirror and the optical axis form an angle of 45 °, the irradiation beam diameter spreads ^20.5 times in the circumferential direction. Therefore, the amount of shift in the circumferential direction (angle) is about 4 mm. When the mirror shift direction is the horizontal direction, the horizontal shift amount is about 4 mm, and the circumferential direction (angle) shift amount is about 3 mm. When the radial shift amount is 3 mm and the circumferential shift amount is 4 mm for a mirror having a diameter of 2 inches, 103 light receiving positions including the center can be secured by one mirror.
Mirror No. 1, the counter number displayed in the “Mirror No. 1 light receiving position” column of the screen is incremented by 1 every time the light receiving position is shifted, and when it reaches 103, “Mirror No. 1 is time to replace” is displayed. To do. This counter is reset when the mirror is replaced. The number of female screws for fixing the mirror and the shift amount may be determined to be appropriate values according to the size of the mirror and the beam irradiation diameter.
As described above, the position where the reflecting mirror can receive light is managed by the number, and when the predetermined threshold value is reached, all the light receiving positions are damaged, and the reflecting mirror is not removed from the laser processing apparatus for inspection. However, it becomes possible to prove that the replacement is necessary.

  Also, in the “mirror No. 1 movement amount setting”, the “diameter (vertical) direction movement amount” is not set, and a numerical value is input only in the “circumference (angle) direction movement amount”, and the mirror When the light receiving position of 1 is changed, mirror No. 1 is a unit of prime number of 360 ° or less excluding 2 °, 3 °, and 5 °, which is a divisor of 360 °. When 1 is rotated, the light receiving position can be efficiently selected without overlapping.

The mirror can be rotated at an arbitrary angle by using the end face of the mirror fixing ring 117 as a worm wheel and meshing with the worm gear to rotate the gear side. It is also possible to control the angle by attaching a motor to the worm gear. Further, the mirror may be integrated with the rotor of the servo motor to control the angle.
The sliding direction of the mirror holder may be 45 ° with respect to the incident direction of the laser. Such a structure is mainly employed in a portion where the beam diameter on the light receiving surface is thin, and it is not necessarily employed in a place where the beam diameter is large and there is no fear of mirror damage.
This structure may be applied not only to the bend mirrors 113 to 115 but also to the half-wave plate 106 and the beam splitter 107. Since the beam splitter 107 has a wedge, when the mounting angle is changed or the beam splitter 107 is shifted in the vertical direction, the optical axis on the transmitted light side of the beam splitter 107 needs to be readjusted.

In the laser processing apparatus according to the first embodiment, the output of the laser oscillator is adjusted by the control DC current value, and an adjustment knob for adjusting the control DC current value inside the laser oscillator is provided. When “Oscillator output decrease” is displayed, the control DC current value inside the laser oscillator is gradually increased with the adjustment knob, and the machining point output without the mask is adjusted to recover to a past point in time. If the oscillator output is within 1% compared to a certain point in the past, it is judged that the oscillator has recovered, and the screen displays “Output has recovered. Machining of the workpiece can be resumed.”
When “relative positional deviation between optical axis and mask” is displayed, the mask position is corrected. There are two types of mask position adjustment, the circumferential direction and the radial direction. The circumferential direction is adjusted by the angle of the servo motor of the mask changer. Initially, the machining point output is measured with a beam (beam used for machining) that has passed through the mask while moving in units of 0.1 °. When the machining point output is larger than the previous measurement value, the machining point output is moved by 0.1 ° in the same direction, and when it is smaller, the machining point output is measured and compared with the previous measurement value. This is repeated as long as the increasing trend continues. Measure at least 3 different angles. Since the peak is past when the measured value is lower than the previous measurement value, the relation of the machining point output to the angle is approximated by a quadratic curve, and the angle corresponding to the peak position is calculated from the approximation formula and set.

Here, the machining point output is measured and compared with the normal output value during machining. If the difference recovers to within 2%, the screen will display “Output is recovered. Machining of the workpiece can be resumed.” If it does not recover, radial adjustment is required. A servo motor that performs positioning in a direction perpendicular to the optical axis is moved horizontally along with the mask changer for adjustment. The movement is performed in units of 100 μm, and the position where the machining point output reaches a peak is determined and set in the same manner as described above. Here, the machining point output is measured, and it is confirmed that it has recovered to the normal output during machining.
When any of the mask positions is adjusted, the same adjustment is required for the remaining other masks. In this case, since the deviation with respect to the optical axis is considered to be substantially equal, adjustment time can be saved by correcting and setting the difference between the set values before and after the previous mask position adjustment (both in the circumferential direction and the radial direction). When the message “Output is restored. Machining of the workpiece can be resumed” appears, the output measurement value at this point can be registered as comparison reference data to be referred to in the subsequent output confirmation.

In uniaxial machining, not only the method of blocking either the reflected light or transmitted light from the beam splitter 107 with a shutter (using only one side of the biaxial simultaneous machining), but all the output is split without splitting the beam. Processing can be concentrated on the shaft. When “single-axis machining” is selected on the screen display, the mirrors 113 and 114 fixed to the common pedestal are placed on the optical path closer to the laser oscillator 101 than the half-wave plate 106 by the air cylinder, and the mirror 115 is connected to the unit 121 or Depending on the selection of the unit 122, it is inserted into the optical path on the transmitted light side or the reflected light side from the beam splitter 107 simultaneously. The optical path length from the mask 105 to the fθ lens is unchanged.
(Embodiment 2)
FIG. 4 is a diagram showing a part of the optical system arrangement of the laser processing apparatus according to Embodiment 2 of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In FIG. 4, the arrangement of the beam splitter 107, the mirror 213, and the pedestal to which they are fixed are shown by a solid line and a dotted line in each case of biaxial machining and uniaxial machining.

  At the time of biaxial processing, the beam splitter 107 is disposed in the optical path of the laser beam and divides the incident laser beam. At the time of uniaxial processing, the beam splitter 107 moves out of the optical path of the laser light, and at the same time, the mirror 213 enters the optical path of the laser light and reflects in a direction different from the traveling direction of the original laser light, and is a second positioning means. Proceed to unit 122.

  As described above, since the laser beam is not split by the beam splitter 107 during the uniaxial machining, the intensity of the laser light is not reduced to ½ compared with the biaxial machining, and the biaxial machining is performed. The workpiece can be processed with a laser beam having the same intensity as the time.

  If the pedestal on which only the beam splitter 107 is fixed without the mirror 213 is taken in and out of the optical path of the laser light, the laser light that has passed through the half-wave plate 106 goes straight through the mirror 108 and goes straight through the mirror 108 during uniaxial processing. To the positioning means.

  According to the present invention, it is possible not only to shorten the processing time by using two lasers but also to use a powerful laser beam without division depending on the material of the workpiece, thereby providing an industrially useful laser processing apparatus.

The figure which shows a part of optical system arrangement | positioning of the laser processing apparatus in Embodiment 1 of this invention The figure which shows the light reception position change means of the mirror of the laser processing apparatus in Embodiment 1 of this invention The figure which shows arrangement | positioning of the change place of the laser receiving position of the mirror in Embodiment 1 of this invention The figure which shows a part of optical system arrangement | positioning of the laser processing apparatus in Embodiment 2 of this invention. Diagram showing conventional laser processing equipment Diagram showing conventional laser processing equipment

Explanation of symbols

101 Laser oscillator 107 Beam splitter (dividing means)
113-115 Bend mirror (reflecting mirror)
121 A unit in which a Z1-axis galvanometer mirror and an fθ lens are incorporated (first positioning means)
122 Unit in which Z2 axis galvanometer mirror and fθ lens are incorporated (second positioning means)
123 Processing table 213 Bend mirror (reflecting mirror)

Claims (3)

A laser oscillator, splitting optical means for splitting the laser light emitted from the laser oscillator, and first and second positioning means for respectively positioning the split laser light to the processing positions on the workpiece. And a laser processing apparatus provided with a moving unit that holds the splitting optical means and puts the splitting optical means in and out of the optical path of the laser beam. 2. The laser processing apparatus according to claim 1, wherein the moving unit puts a reflecting mirror that reflects the laser beam to the second positioning unit at the same time when the dividing optical unit is moved out of the optical path of the laser beam. A laser oscillator, splitting optical means for splitting the laser light emitted from the laser oscillator, and first and second positioning means for respectively positioning the split laser light to the processing positions on the workpiece. An optical path leading to one of the first positioning means and the second positioning means composed of a plurality of reflecting mirrors between the laser oscillator and the splitting optical means with respect to the traveling direction of the laser light. Laser processing device provided with moving mirror moving part

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