JP2009241148A - Laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining apparatus effectively suppressing the error between a position of a laser spot and a machining target position. <P>SOLUTION: The laser beam machining apparatus M includes an allocation section which allocates the machining target position on a machining region to a coordinate position of a coordinate system, and a correction section which, when a designated coordinate position is allocated as the machining target position, suppresses the error between the position of the laser spot and the machining target position by correcting the turning position of a galvanometer mirror based on correction data made to correspond to the designated coordinate position. The spacing between the designated coordinate positions Q, Q made to correspond to the correction data for suppressing the error between the position of the laser spot S and the machining target position is narrower in the region farther from a reference position O than the region nearer the reference position within the coordinate system. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laser processing apparatus.

  The laser processing apparatus includes a laser light source, a galvanometer mirror that reflects the laser beam therefrom, and a converging lens that converges the laser beam reflected by the galvanometer mirror to form a laser spot on the processing region. When a predetermined machining pattern is input, a machining target position on the machining area corresponding to the machining pattern is assigned as a coordinate position on the coordinate system, and the rotational position of the galvano mirror is controlled based on the coordinate position. Thus, the laser spot is moved on the processing region to perform processing.

However, even if the galvano mirror is accurately displaced to the rotation position corresponding to each coordinate position, due to the influence of the aberration of the converging lens, the position of the laser spot on the machining area and the machining target position are not affected. An error will occur. Therefore, there is a conventional laser processing apparatus having a function of suppressing this error (see Patent Documents 1 to 3). Specifically, in this conventional laser processing apparatus, a plurality of correction data (correction value matrix) associated with each coordinate position arranged at equal intervals in the coordinate system is stored in a memory, and the processing target position is The correction data associated with the allocated coordinate position is read from the memory, and the rotation position of the galvano mirror is corrected based on the correction data, thereby suppressing an error between the laser spot position and the processing target position. ing.
JP 62-45493 A JP-A-8-174256 JP 2002-316288 A

  The conventional laser processing apparatus has a configuration in which correction data is associated with each coordinate position arranged at equal intervals in the coordinate system, but the error between the position of the laser spot and the processing target position is calculated. There has been a demand for further technology to suppress.

  The present invention has been completed based on the above circumstances, and an object thereof is to provide a laser processing apparatus capable of effectively suppressing an error between the position of a laser spot and a processing target position. By the way.

  As a means for achieving the above object, a laser processing apparatus according to a first aspect of the present invention is a galvanometer having a laser light source that emits laser light and a galvano mirror that reflects the laser light from the laser light source. A scanner, a converging lens that converges the laser light reflected by the galvanometer mirror to form a laser spot on the processing region, an assignment unit that assigns a processing target position on the processing region to a coordinate position of the coordinate system, and A control unit that moves the laser spot on the processing region by rotating the galvano mirror based on the coordinate position to which the processing target position is allocated by the allocation unit, and a plurality of specified coordinate positions specified from the coordinate system A memory in which a plurality of correction data associated with each of them is stored, and the designated coordinate position is assigned as the processing target position. A correction unit that corrects the rotational position of the galvano mirror based on correction data associated with the designated coordinate position and suppresses an error between the position of the laser spot and the processing target position. In the coordinate system, the distance between the designated coordinate positions is narrower in the area farther from the area near the reference position corresponding to the lens center of the convergent lens.

  The error between the position of the laser spot and the processing target position tends to increase as the distance from the coordinate position (reference position) corresponding to the lens center of the convergent lens increases. Therefore, according to the present invention, the distance between the designated coordinate positions (coordinate positions associated with the correction data) is greater in the area closer to the reference position corresponding to the lens center of the convergent lens in the coordinate system. Is a narrow configuration. As described above, by changing the interval between the designated coordinate positions in the coordinate system in accordance with the degree of the error, the error between the position of the laser spot and the processing target position can be effectively suppressed.

A second invention is the laser processing apparatus according to the first invention, wherein an interval between the designated coordinate positions is gradually narrowed as the distance from the reference position is increased in the coordinate system. It is the composition which is.
According to the present invention, the correction can be performed with high accuracy in accordance with the tendency of the error between the position of the laser spot and the processing target position.

3rd invention is a laser processing apparatus of 2nd invention, Comprising: The space | interval of the said designated coordinate position becomes a structure which becomes exponentially narrow as the distance from the said reference position becomes a far region. .
The error between the position of the laser spot and the processing target position increases exponentially as the distance from the reference position corresponding to the lens center of the convergent lens increases. Therefore, as in the present invention, a configuration in which the interval between the designated coordinate positions is narrowed exponentially as the distance from the reference position is increased is preferable.

A fourth invention is the laser processing apparatus according to any one of the first to third inventions, and is located on each of two straight lines intersecting at the reference position, and the distance from the reference position is the same. The spacing between the designated coordinate positions is different between the two regions.
Even in two regions that are located on two straight lines that intersect at the reference position and have the same distance from the reference position, the error between the position of the laser spot and the processing target position may be different. In this case, it is preferable that the distance between the designated coordinate positions is different between the two regions as in the present invention.

5th invention is the laser processing apparatus of any one of 1st to 4th invention, Comprising: The said correction | amendment part, when coordinate positions other than the said designated coordinate position are allocated as the said process target position, The rotation position of the galvano mirror is corrected based on the specified coordinate position and correction data associated with the specified coordinate position.
When a coordinate position other than the designated coordinate position is assigned as the machining target position, it is preferable to correct the rotational position of the galvano mirror based on the designated coordinate position and the correction data associated with the designated coordinate position.

  According to the present invention, the error between the position of the laser spot and the processing target position can be effectively suppressed.

An embodiment of the present invention will be described with reference to FIGS.
(Overall configuration of laser processing equipment)
FIG. 1 is an overall configuration diagram of a laser processing apparatus according to the present embodiment. In the figure, an example in which a laser processing apparatus M processes a processing object W (in this embodiment, an insulating sheet used for a mobile phone) disposed in a predetermined processing area E on a processing table Z. It is shown.

  The laser processing apparatus M mainly includes a laser light source 10, a galvano scanner 20, and a controller 30. The galvano scanner 20 changes the direction of the laser beam 11 emitted from the laser light source 10 and irradiates the processing area E with the laser beam 11. Specifically, the galvano scanner 20 converges the pair of galvanometer mirrors 20V and 20W for reflecting the laser beam from the laser light source 10 and the laser beam 11 reflected by the pair of galvanometer mirrors 20V and 20W to process the region. And a converging lens 20Z (for example, an fθ lens) that forms a laser spot S on E. By rotating one galvanometer mirror 20V, the laser spot S can be moved in a predetermined direction (corresponding to the X-axis direction of an orthogonal coordinate system described later), and the other galvanometer mirror 20W is rotated. The laser spot S can be moved in the other direction (corresponding to the Y-axis direction of the orthogonal coordinate system) orthogonal to the one direction.

(Electric configuration of laser processing equipment)
As shown in FIG. 2, the controller 30 includes a memory 32 that stores processing data such as characters and graphics, and a CPU 34 (an example of an allocation unit, a control unit, and a correction unit). For example, a console) is connected.

  The input device 31 can input a machining pattern to be formed on the workpiece W in the machining area E. When a predetermined machining pattern is input to the input device 31, the CPU 34 reads machining data (vector data) corresponding to the machining pattern from the memory 32. Then, a plurality of machining points including a start point and an end point are extracted from the read machining data line elements, and each of the extracted machining points is represented as a coordinate position P (in the same figure in the XY orthogonal coordinate system shown in FIG. 3). The coordinate data for each point is generated by assigning to each intersection of two grids orthogonal to each other. At this time, the CPU 34 functions as an “allocation unit”.

  Here, the orthogonal coordinate system is used for the CPU 34 to pseudo-understand each position on the machining area E, and the coordinate position P of each machining point is a laser spot S on the machining area E. Corresponds to the processing target position to be moved. The reference position O of the orthogonal coordinate system is the intersection of the straight line passing through the lens central axis of the convergent lens 20Z and the processing area E. In FIG. 3, a straight machining pattern B1 passing through the reference position O is taken as an example of a machining target, and machining points extracted from this straight machining data are assigned to each coordinate position (P1, P2,... P20). The state is shown.

  Next, the CPU 34 performs correction processing described later on the coordinate data. Thereafter, the CPU 34 temporarily stores the corrected coordinate data in the memory 32 and outputs it through the signal line L at a predetermined timing. The coordinate data output from the CPU 34 is converted from a digital signal to an analog signal by the D / A conversion circuit 36, and then input to each drive circuit (not shown) constituting the galvano drive means 20X, 20Y. Thereby, the laser spot S is scanned on the processing region E by adjusting and controlling the rotational positions of the galvanic mirrors 20W and 20V, and the processing pattern can be applied on the processing target W.

(Correction process)
If the galvanometer mirrors 20W and 20V are rotated according to the coordinate data without performing a correction process described later, for example, pincushion distortion or linearity distortion due to the aberration of the converging lens 20Z occurs. That is, an error (hereinafter referred to as “laser processing error”) occurs between the position of the laser spot S on the processing region E and the processing target position. For example, as shown in FIG. 4, for example, when a rectangular processing pattern B2 (shown by a one-dot chain line in FIG. 4) is used as a processing target and formed on the processing target W without correction processing, the processing actually formed The pattern B3 (shown by a solid line in FIG. 4) bulges outward near the start point and end point of the left and right sides and dents inward near the center, while it dents inward near the start point and end point of the upper and lower sides and outwards near the center. It becomes a bulging shape.

  Therefore, correction data for correcting the rotational positions of the galvanometer mirrors 20W and 20V is required so as to suppress the laser processing error. This correction data is data for correcting the coordinate data (coordinate position P) in this embodiment. This correction data can be acquired as follows. That is, for each coordinate position P in the orthogonal coordinate system, the laser processing error is measured by driving the galvano scanner 20 based on the coordinate data without correcting the coordinate data generated by assigning the processing target position. The amount of change in coordinate data (coordinate position) necessary to cancel out this laser processing error is correction data.

  By the way, as with the conventional laser processing apparatus, correction data is associated one by one with all coordinate positions P (all intersection points of two grids in FIG. 3) arranged at equal intervals on the orthogonal coordinate system. If the correction table (correction value matrix) is used, the same correction accuracy can be expected regardless of which coordinate position P in the orthogonal coordinate system is assigned. However, there is a demerit that the amount of correction data increases and the memory capacity burden increases.

  However, when the measured value of the laser processing error is analyzed, it can be seen that the laser processing error tends to increase as the coordinate position P is farther from the reference position O. In other words, the laser processing error tends to increase as the position where the laser beam 11 from the galvano scanner 20 enters the converging lens 20Z is closer to the periphery of the converging lens 20Z. That is, the degree of laser processing error varies depending on each area of the orthogonal coordinate system, and the same correction accuracy is not necessarily required in all areas of the orthogonal coordinate system.

  Therefore, in the present embodiment, the correction table associates correction data one by one with only some coordinate positions P on the orthogonal coordinate system. Hereinafter, the coordinate position P associated with the correction data is particularly referred to as “designated coordinate position Q” (indicated by “x” in FIG. 3). Specifically, in the orthogonal coordinate system, the distance between the designated coordinate positions Q and Q is gradually narrowed as the distance from the reference position O increases. More specifically, the fourth, seventh, ninth, and tenth coordinate positions P from the reference position O on the X axis (Y axis) are designated coordinate positions Q. Also, the intersection of a straight line (correction grid) parallel to the Y axis passing through the designated coordinate position Q on the X axis and a straight line (correction grid) parallel to the X axis passing through the designated coordinate position Q on the Y axis , The designated coordinate position Q. As a result, the coordinate positions P1, P2, P4, and P7, the reference position O, the coordinate positions P14, P17, P19, and P20 are the designated coordinate positions Q on the processing pattern B1 in FIG. The coordinate data is corrected based on the correction data associated with each.

  The CPU 34 sets the machining target positions at coordinate positions P other than the designated coordinate position Q (coordinate positions P3, P5, P6, P8 to P10, P11 to P13, P15, P16, and P18 on the machining pattern B1 in FIG. 3). When assigned, the coordinate data is corrected by the gravity center position calculation process (for example, the interpolation calculation process such as bilinear or trilinear interpolation) using the correction data of the designated coordinate position Q located in the vicinity of the coordinate position P. For example, the coordinate data of the coordinate positions P11 to P13 is corrected based on the designated coordinate position Q (reference position O, coordinate position P14) in the vicinity thereof and the correction data associated therewith.

(Effect of this embodiment)
As described above, when the machining target position is assigned to the coordinate position P in the vicinity of the reference position O, the laser machining error is small, so that even if the gap between the designated coordinate positions Q and Q is increased and roughly corrected. The effect on processing quality is relatively small. On the other hand, when the machining target position is assigned to the coordinate position P that is distant from the reference position O, the laser machining error is large, so that the detailed coordinate correction is performed by narrowing the interval between the designated coordinate positions Q and Q. There is a need to do.

  Therefore, in the present embodiment, the correction table is created so that the distance between the designated coordinate positions Q and Q gradually decreases as the distance from the reference position O increases in the orthogonal coordinate system. Therefore, when a processing target position is assigned to a coordinate position near the reference position O (see P7 to P12 on the processing pattern B1 in FIG. 3), a rough correction is performed, while coordinates far from the reference position O are performed. When the processing target position is assigned to the position (see P1 to P6 and P13 to P20 on the processing pattern B1 in FIG. 3), detailed correction can be performed. Therefore, the laser processing apparatus M of the present embodiment can reduce the amount of correction data while suppressing a decrease in correction accuracy, compared to a configuration in which all coordinate positions in the orthogonal coordinate system are designated as designated coordinate positions.

  Further, if the interval between the designated coordinate positions is uniformly opened in, for example, two intersections (three squares in FIG. 3) in the entire region of the orthogonal coordinate system, the amount of correction data can be reduced as compared with the present embodiment. The correction accuracy with respect to the coordinate position away from the reference position O is lowered. In addition, the amount of correction data is small, so that the burden of interpolation calculation processing for compensating the correction data is large and the processing speed is reduced. On the other hand, the laser processing apparatus M of the present embodiment can reduce the load of the interpolation calculation processing and suppress the decrease in the processing speed while maintaining high correction accuracy.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the correction table is configured such that the distance between the designated coordinate positions Q and Q gradually decreases as the distance from the reference position O increases in the orthogonal coordinate system. In accordance with the tendency of the laser processing error, correction can be performed with high accuracy. However, the present invention is not limited to this. For example, only the region far from the reference position O may be configured such that the interval between the designated coordinate positions is narrower than other regions.

  (2) In the above embodiment, the rotational position of the galvanometer mirrors 20V and 20W is corrected by a software process for correcting the coordinate data (coordinate position) itself based on the correction data. Based on the correction data, the rotational position of the galvano mirrors 20V and 20W may be corrected by hardware processing for adding / subtracting the signal level to / from the analog signal applied to each drive circuit constituting the galvano drive means 20X and 20Y. .

  (3) In the above embodiment, as shown in FIG. 3, two lines that are located on each of two straight lines (X axis and Y axis) intersecting at the reference position O and have the same distance from the reference position O are used. The designated coordinate positions Q and Q have the same interval between the regions (hereinafter referred to as “equal distance regions”). However, depending on the characteristics of the converging lens 20Z, the error between the position of the laser spot and the processing target position may differ between the equidistant regions. In this case, as shown in the present invention, for example, as shown in FIG. 6, it is preferable that the designated coordinate positions Q and Q have different intervals between two equidistant regions. In the example of FIG. 5, on the Y axis, the fourth, seventh, ninth, and tenth coordinate positions P from the reference position O are designated as the designated coordinate positions Q, whereas the X axis In the above, the third, sixth, eighth, ninth, and tenth coordinate positions P from the reference position O are designated as the designated coordinate positions Q.

(4) The error between the position of the laser spot S and the processing target position may increase exponentially as the distance from the reference position O increases. Therefore, as shown in FIG. 6, the interval between the designated coordinate positions Q and Q is narrowed exponentially (Y = −N ^X N: natural number) as the distance from the reference position O becomes far. A configuration is preferred. In the example of FIG. 6, the eighth, twelfth, fourteenth, and fifteenth coordinate positions P from the reference position O on the X axis (Y axis) are designated coordinate positions Q. That is, the intervals between the designated coordinate positions Q and Q are squares of 2 (8 squares, 4 squares, 2 squares, and 1 square). In addition, when the square number is 2 as described above, it is possible to speed up and simplify the arithmetic processing in the CPU 34.

1 is an overall configuration diagram of a laser processing apparatus according to an embodiment of the present invention. Block diagram of laser processing equipment Schematic diagram showing Cartesian coordinate system Schematic diagram showing the target machining pattern and the machining pattern formed without correction Schematic diagram showing the specified coordinate position of the modification (part 1) Schematic diagram showing the specified coordinate position of the modification (part 2)

Explanation of symbols

M ... Laser processing apparatus 10 ... Laser light source 11 ... Laser light 20 ... Galvano scanner 20V, 20W ... Galvano mirror 20Z ... Converging lens 32 ... Memory 34 ... CPU (an example of an allocation unit, a control unit, and a correction unit)
E ... Processing area O ... Reference position P ... Coordinate position Q ... Designated coordinate position S ... Laser spot

Claims (5)

A laser light source for emitting laser light;
A galvano scanner having a galvano mirror that reflects the laser light from the laser light source so as to be rotatable;
A converging lens that converges the laser light reflected by the galvanometer mirror to form a laser spot on the processing region;
An allocation unit that allocates a processing target position on the processing region to a coordinate position of a coordinate system;
A control unit that moves the laser spot on the processing region by rotating the galvanometer mirror based on the coordinate position to which the processing target position is allocated by the allocation unit;
A memory for storing a plurality of correction data associated with each of a plurality of designated coordinate positions designated from the coordinate system;
When the designated coordinate position is assigned as the machining target position, the rotational position of the galvano mirror is corrected based on the correction data associated with the designated coordinate position, and the position of the laser spot and the machining target are corrected. A correction unit that suppresses an error from the position,
In the coordinate system, a laser processing apparatus having a configuration in which a distance between the designated coordinate positions is narrower in an area farther from an area close to a reference position corresponding to a lens center of the convergent lens. The laser processing apparatus according to claim 1,
In the coordinate system, as the distance from the reference position becomes far, the interval between the designated coordinate positions gradually decreases. The laser processing apparatus according to claim 2,
The interval between the designated coordinate positions is configured to become exponentially narrow as the distance from the reference position becomes far. The laser processing apparatus according to any one of claims 1 to 3,
The distance between the designated coordinate positions is different between two regions located on each of two straight lines intersecting at the reference position and having the same distance from the reference position. The laser processing apparatus according to any one of claims 1 to 4, wherein:
When the coordinate position other than the specified coordinate position is assigned as the processing target position, the correction unit is configured to rotate the galvano mirror based on the specified coordinate position and correction data associated with the specified coordinate position. It is the structure which correct | amends.

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