KR100824494B1 - A laser processing apparatus - Google Patents

Abstract

An object of the present invention is to easily improve the positional accuracy of the processing hole and to reduce the occurrence of distortion, when simultaneously processing a plurality of holes using the HOE or when performing a single long hole without using the HOE. It is to obtain the laser processing apparatus which can be done.

In the present invention, two-dimensional scanning is performed in a direction substantially perpendicular to each other by rotationally driving the HOE 10 for spectroscopy of the laser beam 1 with a plurality of laser beams and the mirror surfaces 2a and 2b corresponding to the spectroscopic laser beams. In the laser processing apparatus equipped with two galvano scanners and the f (theta) lens 4 which collects and irradiates a two-dimensional scanned laser beam toward a workpiece | work, the mirror surface 2a by which the galvano scanner which receives a laser beam is rotated for the first time is provided. Is incident on the axial direction side of the drive shaft of the galvano scanner. Thereby, the pattern rotation angle in the edge part of the scan area 7 becomes small, and positional accuracy improves.

Laser Light, Laser Oscillator, Galvano Scanner, Laser Spectroscopy, Spectral Pattern

Description

Laser processing device {A LASER PROCESSING APPARATUS}

BRIEF DESCRIPTION OF THE DRAWINGS The ray tracing diagram explaining the principle of the laser processing method implemented in the laser processing apparatus using HOE by Embodiment 1 of this invention.

FIG. 2 is an enlarged view of the ray tracing in the mirror plane of the first galvano scan mirror closer to the placement position H of the HOE in FIG. 1; FIG.

FIG. 3 is an enlarged view of the ray tracing in the normal direction of the mirror surface of the first galvano scan mirror shown in FIG. 2; FIG.

4 is an enlarged view of the ray tracing in the mirror plane of the second galvano scan mirror which receives the reflected light from the first galvano scan mirror in FIG.

5 is a view for explaining the rotation angle of the HOE spectral pattern in the light receiving surface of the f? Lens receiving the reflected light from the second galvano scan mirror in FIG. 1;

FIG. 6 is a diagram showing a relationship between the deviation angles η and the angles θ12 and θ23 defined as shown in FIG. 5 when m and n shown in FIG. 2 are m> n.

FIG. 7 is a diagram showing a relationship between the deviation angles η and the angles θ12 and θ23 defined as shown in FIG. 5 when m and n shown in FIG. 2 are m <n.

FIG. 8 is a diagram showing a relationship between a magnitude relationship between m and n shown in FIG. 2 and a maximum rotation angle by angles θ12 and θ23 defined as shown in FIG. 5.

FIG. 9 shows a HOE spectral pattern at four corners of the scan area, and FIG. 9 (1) is a conceptual view at the time of vertical positioning in which the long direction of the HOE spectral pattern is set substantially parallel to the direction of the drive shaft of the first galvano scanner. 9 (2) is a conceptual diagram at the time of horizontal positioning in which the longitudinal direction of the HOE spectral pattern is set substantially parallel to the direction orthogonal to the drive shaft direction of the first galvano scanner.

Fig. 10 is a diagram showing the relationship between the rotation angle of the HOE spectral pattern in the four corner portions of the scan area by changing the area of the scan area and the direction of the drive shaft of the first galvano scanner.

FIG. 11 is a conceptual diagram of laser processing performed in the case of vertical positioning shown in FIG. 9 (1). FIG.

FIG. 12 is a conceptual diagram of laser processing performed in the case of horizontal placing shown in FIG. 9 (2). FIG.

It is a conceptual diagram explaining the principle of the laser processing method implemented in the laser processing apparatus which does not use HOE by Embodiment 2 of this invention.

14 is a conceptual diagram illustrating a general configuration and operation of a laser processing apparatus.

15 is a conceptual diagram illustrating a configuration example of a multiaxial laser machining apparatus.

FIG. 16 is a conceptual diagram illustrating spectroscopy by HOE applied to the laser processing apparatus shown in FIG. 14. FIG.

FIG. 17 is a ray tracing diagram for explaining two-dimensional scanning by two galvano scanners and two galvano scan mirrors in the laser processing apparatus shown in FIG. 14; FIG.

FIG. 18 shows the relationship between the light beam direction and the scan angles η, ξ and elevation angle Φ in FIG. 17, and a diagram for obtaining cosine and sinusoidal components in the light beam direction, and a diagram for obtaining cosine, sinusoidal and tangent components in the light beam direction. .

FIG. 19 is a diagram illustrating a relationship between distortion and an elevation angle Φ on the screen shown in FIG. 17. FIG.

20 is a schematic diagram illustrating distortion occurrence of a HOE spectral pattern in each portion of a scan region.

Fig. 21 is a schematic diagram illustrating the occurrence of distortion of a long hole pattern in each portion of a scan area in a case where a long hole such as an ellipse or a rectangle is performed without using the HOE.

* Description of the symbols for the main parts of the drawings *

1: laser light

2a: galvano scan mirror (first galvano scan mirror)

2b: galvano scan mirror (second galvano scan mirror)

3a: galvano scanner (first galvano scanner)

3b: galvano scanner (second galvano scanner)

9a, 9b: laser head 12: HOE spectral pattern

13: long hole pattern 16: long hole pattern

η, ξ: deviation angle (scanning angle)

TECHNICAL FIELD This invention relates to the laser processing apparatus which makes a fastening hole or a through hole in electronic materials, such as a printed circuit board material and a ceramic green sheet.

Since the object to be processed, such as a printed circuit board material or a ceramic green sheet, has a planar shape, in the conventional laser processing apparatus, for example, two laser beams are scanned two-dimensionally using two galvano scanners as shown in FIG. (Iv) and irradiate the object to be processed to perform perforation processing (for example, Patent Document 1). Here, the outline is demonstrated with reference to FIG. 14 in order to make understanding of this invention easy.

14 is a conceptual diagram illustrating a general configuration and operation of a laser processing apparatus. The laser processing apparatus shown in FIG. 14 is provided with the galvano scan mirrors 2a and 2b, the galvano scanners 3a and 3b, the f (theta) lens 4, and the table on which the workpiece | work 5 is mounted.

The galvano scan mirror 2a is a first galvano scan mirror that first receives the laser light 1 output by a laser oscillator (not shown), and its mirror surface is displaced with rotation of the drive shaft of the galvano scanner 3a. Then, the optical axis of the incident laser light 1 is deflected in one direction (for example, the X axis direction), and it is sent to the second galvano scan mirror 2b. The galvano scan mirror 2b which receives a laser beam for the second time has its mirror surface displaced with the rotation of the drive shaft of the galvano scanner 3b, and is orthogonal to the optical axis of the incident laser beam 1. The deflection scan is carried out in the other direction (in the present example, Y-axis direction) and sent to the f? Lens 4. The fθ lens 4 condenses and irradiates the laser beam scanned two-dimensionally in the XY plane on the workpiece 5 as described above. Thereby, many machining holes 6 are formed in the workpiece | work 5 in the scanning area | region 7 which is the range which can scan the laser beam 1 two-dimensionally by the galvano scanner 3a, 3b.

However, the productivity of laser processing greatly depends on the positioning speeds of the two galvano scanners as can be understood from the above description. Therefore, although the positioning speed of a galvano scanner continues to improve year by year, since it is a mechanical operation, it limits itself from problems, such as a vibration and heat generation. In preparation for the case where the positioning speed has become a limit, a method of increasing the number of beams that can be irradiated at the same time as a method of improving productivity has been studied and put into practical use. There are two ways to this. One is a method of multiaxializing as shown in FIG. 15, and the other is a method of using a holographic optical element (HOE) as shown in FIG.

It is a conceptual diagram which shows the structural example of the laser processing apparatus which multiaxialized. In Fig. 15, the laser heads 9a and 9b are set with the galvano scan mirrors 2a and 2b, the galvano scanners 3a and 3b and the f theta lens 4, respectively, by the spectroscope 8; The spectroscopic laser light 1 is supplied at the same time, and is configured to simultaneously perform punching processing on each processing work 5.

15 is an example of the configuration of two heads, but an attempt has been made to improve productivity by increasing the number to four heads at present. In this case, however, the galvano scanner and the galvano scan mirror should be increased from one set to two sets and four sets, and the expensive fθ lenses should be increased to two or four, too, and there are many problems in terms of maintenance and price.

FIG. 16 is a conceptual diagram illustrating spectroscopy by HOE applied to the laser processing apparatus shown in FIG. 14. As shown in FIG. 16, since the HOE 10 can spectrograph the laser beam 1 in a plurality of directions, in the laser processing apparatus using the HOE 10, a shape having any combination of a plurality of round holes having a processing pattern is combined. Although there is a limitation limited to the processing pattern, the number of laser beams can be increased without increasing the laser head, so that the above problem can be avoided and the speed can be surely increased.

The processing method in the laser processing apparatus using the HOE 10 will be described. The HOE 10 is provided at the input terminal of the first galvano scan mirror 2a to utilize the coherence of the laser. The beam passing through is divided into small pieces, each having a phase difference, interfering with each other, and being designed to be strong in each other and weak in each other. Since the information before the HOE incident is transmitted to the interference fringes that strengthen each other, one beam is processed as if it is divided into a plurality.

Although there is a limitation that the processing pattern is limited in this way, in order to repeat the same pattern processing, a processing method using HOE (hereinafter, abbreviated as "HOE processing") is very advantageous in productivity, and the price of the product must be suppressed. The use of HOE processing has been increasing mainly in the electronic component industry.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2002-66769

However, since the blind holes and through holes formed in the object to be processed are very small, the positional accuracy at the time of processing is also very important. However, even in the conventional HOE processing or the processing without using the HOE, the hole shape is elliptical. It is difficult to improve the positional accuracy of this processing hole in the conventional long hole processing which performs a square etc.

Specifically, in the conventional HOE processing, there is less distortion at the center of the scan area and is in a good processing state, but as described below (FIGS. 17 to 19), the galvano scan mirror is tilted and the irradiation position of the laser light is changed to the fθ lens. If it is taken to the periphery of the (i.e., the periphery of the scan area), distortion and inclination of the shape occur (see Fig. 20). This point is the same when the above-mentioned long hole processing is performed even in single hole processing without using HOE (see Fig. 21). This is a major factor in the deterioration of the positional accuracy at the time of the HOE processing or the long hole processing in the single hole processing without using the HOE, and it is necessary to reduce it as much as possible.

17 to 19, a phenomenon in which distortion and inclination of a shape occur in the periphery of the scan area will be described. FIG. 17 is a ray tracing diagram for explaining two-dimensional scanning by two galvano scanners and two galvano scan mirrors in the laser processing apparatus shown in FIG. 14. FIG. 18 shows the relationship between the light beam direction, the scan angles η, ξ and elevation angle Φ in FIG. 17, (1) is a diagram for obtaining a cosine component and a sinusoidal component in the light beam direction, and (2) a light beam direction. It is a figure which calculates the cosine component, the sinusoidal component, and the tangent component. FIG. 19 is a diagram showing a relationship between the distortion and the elevation angle φ on the screen shown in FIG. 17.

In FIG. 17, the point A represents the mirror plane position of the first galvano scan mirror 2a, and the point B and the point B 'shown immediately above indicate the mirror plane position of the second galvano scan mirror 2b. . Now, if point B is the origin and three orthogonal axes of X, Y, and Z are defined as indicated by arrows in the figure, the first reflection is performed at the first galvano scan mirror 2a at point A. In the first galvano scan mirror 2a at point A, the incident laser light is reflected at the angle? Deflection in the Y-axis direction. The reflected laser beam is incident on the mirror surface position B 'of the second galvano scan mirror 2b at the point B, and is thus subjected to deflection operation in the XZ plane to be reflected and directed toward the fθ lens 4. Take the path to In FIG. 17, the 1st upper limit which divided | segmented the f (theta) lens 4 whose lens surface is parallel to XY plane is shown.

At this time, if the deviation angle from the Z-axis to the X-axis in the second galvano scan mirror 2b at point B is ξ, the laser beam exiting the laser oscillator (not shown) is in the Y-axis direction and the X-axis direction. Along the optical path R at which the scanning angles are η and ξ respectively, the light is incident at an upper position away from the Y-axis direction in the first upper limit of the fθ lens 4 in the X-axis direction, and is a scan area 7 immediately below shown in FIG. The light is focused on each part of the screen 11.

Direction cosines L, M, and N of the optical path R at this time are as shown in FIG.

L = COS eta Sinξ... (One)

M = Sin (2)... (2)

N = COS η COSξ (3). (3)

Becomes

Since the upper position within the first upper limit of the fθ lens 4 where the optical path R collides is represented by an elevation angle φ from the X-axis direction to the Y-axis direction from the origin in the XY plane,

TanΦ = M / L = tanη / sinξ. (4)

Becomes

Since such a scanning deflection angle is used, when a two-dimensional image is produced by the fθ lens 4 having optical axis rotational symmetry, image distortion inevitably occurs in the periphery of the screen 11. That is, in consideration of the case where the deviation angles ξ and η are deflections at an isometric velocity, and the maximum deflection angles are the same, an ideal fθ lens is used, so that the horizontal and vertical directions passing through the center of the screen (that is, X in the first upper limit) are used. There is no distortion on the axial or Y axis). However, when the deviation angle η and the deviation angle ξ are changed equally, the elevation angle Φ does not become 45 degrees from the equation (4), and the corner portions of the figure on the upper surface have distortion as shown by the solid line in FIG. 19. It becomes.

Since it is difficult to correct this distortion with the fθ lens 4, in the related art, the vibration method of the deviation angles ξ and η in the two galvano scanners 3a and 3b is tanη from equation (4). Not only is it changed so that it is sin, but also it is coped with by fine adjustment and control based on the characteristic by the position of the f (theta) lens 4, etc.

However, by controlling the deviation angles in the galvano scanners 3a and 3b, the position of each part having the distortion shown by the solid line in FIG. 19 can be brought to the correct position indicated by the dotted line. At the position a pattern spectroscopically formed with HOE 10 is formed.

It is a schematic diagram explaining the distortion generation of HOE spectral pattern in each part of a scan area | region. That is, if the distortion in these corner parts is corrected by the deviation angle control in the galvano scanners 3a and 3b as described above, as shown in Fig. 20, the rotation occurs in the HOE spectral pattern 12 itself. , A plurality of round holes are formed to be inclined.

21 is a schematic diagram explaining the generation of distortion of the long hole pattern in each part of the scan area in the case where a long hole such as an ellipse or a quadrangle is performed since the HOE is not used. In the punching process which does not use HOE, the hole processing of the shape according to the opening shape of a mask is performed. Among them, in the case of round machining, the inclination does not become a problem at all since the circle remains round even if an angle is applied. However, in the case of an elongated hole shape such as an ellipse or a square, the phenomenon shown in FIG. 19 occurs in the same manner, and as shown in FIG. 21, the long hole pattern 13 rotates, so that the processing hole is inclined.

As described above, in the case of irradiating as a HOE spectral pattern in which a plurality of round holes are combined using a HOE, or even in single hole processing without using the HOE, the hole shape is formed in a long hole such as an ellipse or a square. Since the inclination occurs and this inclination causes the positional deviation, it has been difficult to improve the positional accuracy of the processing hole in the past. In order to improve the positional accuracy of the processing hole, it is necessary to minimize the rotation angle of the processing pattern described above, but the problem is how to realize it.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and in the case of simultaneously processing a plurality of holes using a HOE or when performing a single long hole processing without using a HOE, the positional accuracy of the processing hole is simply improved or distorted. An object of the present invention is to obtain a laser processing apparatus that can reduce the number of.

In order to achieve the above object, the present invention provides a laser oscillator for emitting laser light, a set of galvano scanners for two-dimensional scanning of the laser light emitted from the laser oscillator, and the set of galvano And a f? Lens for focusing and irradiating the laser light scanned by the scanner on the object to be processed, and entering the first galvano scanner disposed on the oscillator side on the laser optical axis of the set of galvano scanners. The laser beam is set so that the long axis direction side among the long axis and short axis which exist in the irradiation pattern is directed to the axial direction side of the drive shaft of a said 1st galvano scanner.

According to this invention, the direction of the irradiation pattern in the laser beam which injects into the optical scanning system which produces | generates the two-dimensional scanning laser beam irradiated to the to-be-processed workpiece (workpiece) is determined. Specifically, the long axis direction side of the long axis and the short axis present in the irradiation pattern of the laser beam incident on the first galvano scanner receiving the laser light is not the direction orthogonal to the drive axis, but the axis direction side of the drive shaft. The rotation pattern of the irradiation pattern in the scan area is reduced only by taking a simple measure, so that a plurality of holes can be used simultaneously by using the HOE. In the case of machining, the positional accuracy can be improved, and the occurrence of distortion can be suppressed low when a single long hole machining is performed without using the HOE.

According to the present invention, in the case of simultaneously processing a plurality of holes using the HOE or in the case of performing a single long hole processing without using the HO E, the positional accuracy of the processing hole is easily improved and the distortion is generated. The effect that can be planned is shown.

EMBODIMENT OF THE INVENTION Below, with reference to drawings, preferred embodiment of the laser processing apparatus and laser processing method which concern on this invention is described in detail.

Embodiment 1.

BRIEF DESCRIPTION OF THE DRAWINGS It is a ray tracing diagram explaining the principle of the laser processing method implemented with the laser processing apparatus using HOE by Embodiment 1 of this invention. FIG. 2 is an enlarged view of the ray tracing in the mirror plane of the first galvano scanner mirror closer to the placement position H of the HOE in FIG. 1. FIG. 3 is an enlarged view of the ray tracing in the normal direction of the first galvano scanner mirror surface shown in FIG. 2. FIG. 4 is an enlarged view of the ray tracing in the mirror plane of the second galvano scanner mirror that receives the reflected light from the first galvano scanner mirror in FIG. 1. FIG. 5 is a view for explaining the rotation angle of the HOE spectral pattern in the light receiving surface of the f? Lens receiving the reflected light from the second galvano scanner mirror in FIG. 1. In addition, the name and code | symbol of a component use the name and code used by the prior art, such as FIG. 14, as it is for convenience of description.

In FIG. 1, the arrangement position H of the HOE, the first and second galvano scan mirrors 2a and 2b, and the fθ lens 4 are shown. If the center of the mirror plane of the galvano scan mirror 2b is defined as the coordinate origin (O, O, O), and as defined by the arrows in the figure, three orthogonal axes of X, Y, and Z are defined, the arrangement position H of the HOE is (X , Y, Z) = (-1, -k, O) at the coordinate position. The galvano scan mirror 2a is disposed at a position separated by the optical distance k from the position H in the Y-axis direction, and the galvano scan mirror is positioned at an optical distance 1 in the X-axis direction from the galbino scan mirror 2a. 2b) is arrange | positioned, and f (theta) lens 4 is arrange | positioned from the galvano scan mirror 2b in the Z-axis direction by the optical distance s.

As described in Fig. 14, the galvano scan mirror 2a is displaced in accordance with the rotation of the drive shaft of the galvano scanner 3a. The drive shaft of the galvano scanner 3a faces the Z-axis direction. In addition, the mirror surface of the galvano scan mirror 2b displaces with rotation of the drive shaft of the galvano scanner 3b. The drive shaft of the galvano scanner 3b faces the Y-axis direction.

By the way, since the spectral pattern by HOE repeats with regularity, it can be made not only linear but also a lattice shape. Anyway, the spectral pattern by HOE has a longitudinal direction as a process pattern of the shape which combined several plural round holes. Therefore, here, the pattern shape is replaced with a rectangle to simplify the reflection, and the square pattern is reflected and deflected by the galvano scan mirrors 2a and 2b, and then the scanning area 7 immediately below shown in FIG. In the case of transferring onto the phosphor screen 11, how the periphery of the rectangle rotates was examined. In addition, the matter described here can also be applied as it is when the HOE is replaced with a mask and a long hole shape other than a round shape such as a single ellipse or a square is produced.

In FIG. 1, the position {A (X, Y, Z) on the galvano scan mirror 2a which generate | occur | produces three light beams A1, A2, A3 from the position H, and receives them for the first time = (-l, 0, 0) On the plane perpendicular to the Y axis (XZ plane), as shown in detail in FIG. 2, a rectangle with one side 2n and 2m is drawn, and the vertices are three rays A1, A2, and A3. Let this pass. These three rays A1, A2, and A3 can be represented by Equation (1).

In addition, as shown in FIG. 3, the mirror surface of the galvano scan mirror 2a is angle | corner in the state shown by the solid line of incidence angle "45 degree + (eta)" from the state shown by the dashed line which the angle of incidence and reflection is 45 degree. When tilted by η, if these three rays A1, A2, A3 are reflected at points P1, P2, P3 on the galvano scan mirror 2a, the points P1, P2, P3 on the galvano scan mirror 2a are It can be expressed as Equation 2.

only,

Since the mirror plane of the galvano scan mirror 2a is not limited in size, it can be represented by the equation α (x + l) + βy = 0, so that the three rays A1, A2, and A3 are the galvano scan mirror 2a. When the light beams reflected as described above in the mirror plane of B1 are B1, B2, and B3, the three reflected light beams B1, B2, and B3 can be expressed by Equation (3).

Next, in the galvano scan mirror 2b in which the YZ plane including the coordinate origin (0, 0, 0) is the mirror plane, as shown in detail in FIG. 4, the mirror plane has the Y axis as the rotation center,- Rotational displacement is made from the X-axis side toward the + Z-axis side. In FIG. 4, the case where it shifts by the angle ξ again toward the + Z axis side from the state which inclined 45 degrees from the -X axis side toward the + Z axis side is shown. The mirror surface of the galvano scan mirror 2b having the deviation angle ξ is an equation such that γx + δy = 0 using γ and δ of γ = sin ξ-cos ξ and δ = cos ξ + sin ξ. It can be represented as

The three reflected light beams B1, B2, B3 are reflected at points Q1, Q2, Q3 on the mirror surface of the galvano scan mirror 2b having such a deviation angle ξ. Q3 may be represented as in Equation 4.

only,

When the reflected light beams are C1, C2, and C3, these three reflected light beams C1, C2, and C3 can be expressed as in Equation (5).

When the points at which these three reflected light beams C1, C2, C3 intersect the surface of the fθ lens 4 are Rl, R2, and R3, R1, R2, and R3 become rectangular vertices, and these vertices R1, R2 , R3 may be represented as in Equation 6.

Here, as shown in Fig. 5, the angle formed by the line connecting the vertex R1 and the vertex R2 with respect to the vertical direction (Y-axis direction) is θ12, and the line connecting the vertex R2 and the vertex R3 is the horizontal direction (X Θ12 and θ23 are parameters representing degrees of rotation of the HOE spectral pattern, respectively.

Therefore, the angles θ12 and θ23 are plotted against a change in one deviation angle η, and the change in the rotation angle of the HOE spectral pattern (that is, the degree of positional deviation at four corners of the scan area shown in FIG. 19) is examined. 6 and 7 were obtained. FIG. 6 is a diagram showing the relationship between the deviation angles η and the angles θ12 and θ23 defined as shown in FIG. 5 when m and n shown in FIG. 2 are m> n. FIG. 7: is a figure which shows the relationship between the deviation angle (eta) and the angles (theta) 12 and (theta) 23 defined as shown in FIG. 5, when m and n shown in FIG. 2 are m <n.

However, in this calculation, the other deviation angle ξ was changed so that the elevation angle shown in equation (4) was 45 degrees. Specifically, tan? = Sin ξ and Tan? The optical distances l, k, s are values of actual optical systems, and the remaining parameters m, n are m = n and m = n as an example of m> n (Fig. 6), and m <n As an example, the case where m = 6 and n = 12 (FIG. 7) was employ | adopted.

From the calculation result, with the increase in the deviation angle η, the angle θ12 shows a large tendency to increase in the case of m> n and m <n. Therefore, the rotation angle increases and the degree of positional deviation deteriorates, but the angle θ23 Has a slight tendency to increase, so that the increase in rotation angle is extremely small. The angle of rotation by the angle θ23 increases in the case of m <n than in the case of m> n, but the increase in the angle of rotation of the angles θ12 and θ23 with respect to the increase in the deviation angle η is smaller in calculation. It turned out.

8 is a figure which shows the relationship between the magnitude relationship of m and n shown in FIG. 2, and the rotation angle maximum value by angle (theta) 12 and (theta) 23 defined as shown in FIG. As shown in Fig. 8, the maximum value of the rotation angle indicates that the value of the angle θ12 is larger than that of the angle θ23, but it is clear that the case where n is larger than m is the whole of the angle θ12 and the angle θ23. The maximum rotation angle becomes smaller.

This is an incident form of the first galvano scan mirror 2a that receives the laser light output by the HOE for the first time, and the longitudinal direction side of the HOE spectral pattern that the HOE outputs is the galvano scan mirror 2a. When it is set in the incidence form that becomes a parallel direction so that it may face the direction of the Z axis | shaft which is the rotation axis of, the rotation angle at the time of the transfer of the workpiece | work shape to a workpiece will be suppressed low, ie, the position deviation in the quadrangular part of a scan area | region It means getting smaller. This measure can be realized by determining the installation form of the HOE itself when there is no optical system between the HOE and the galvano scan mirror 2a, and when the optical system is present, the whole including the HOE and the optical system. It can be realized by making it the incidence form mentioned above.

Next, since the validity of the "incident form of the 1st galvano scan mirror 2a to the mirror surface" discovered from the calculation result as mentioned above was concretely verified by the real machine, the verification content is shown in FIG. It demonstrates with reference to FIG. 12 and Table 1. FIG. In addition, in a practical real machine (FIG. 11, FIG. 12), the optical system does not exist between HOE and the 1st galvano scan mirror 2a. Between the HOE and the first galvano scan mirror 2a, the laser light transmitted through the HOE is transmitted to or reflected from an optical element such as a single lens or a plurality of lenses or mirrors, and then guided to the galvano scan mirror 2b. When such an optical system exists, the above-described measures of the "incident mode on the mirror surface of the first galvano scan mirror 2a" may be taken with the optical system or the like.

9 conceptually shows a HOE spectral pattern at each corner of the scan area. As shown in FIG. 9, HOE is (1) the longitudinal direction side of the HOE spectral pattern 14a is parallel to the drive-axis direction (X-axis direction in FIG. 9) of the 1st galvano scan 3a. When set (this is called "vertical"), and (2) the longitudinal direction side of the HOE spectroscopic pattern 14b is orthogonal to the drive shaft direction (the X-axis direction in FIG. 9) of the first galvano scanner. The case where this was set to the direction parallel to a direction (Y-axis direction) (this is called "horizontal placement") was prepared.

And the laser processing apparatus using HOE is a structure which provided the HOE 10 in the input terminal of the 1st galvano scan mirror 2a in the structure shown in FIG. 14, as shown in FIG. The HOE 10 spectroscopy the laser beam 1 output from the laser oscillator (not shown) as shown in FIG. 3 and applies it to the first galvano scan mirror 2a. Although not shown in FIGS. 11 and 12, as shown in FIG. 14, the first galvano scan mirror 2a is connected to the drive shaft of the first galvano scanner 3a. The second galvano scan mirror 2b is connected to the drive shaft of the second galvano scanner 3b.

In the laser processing apparatus using such a HOE, the laser processing is performed by setting the HOE 10 vertically as shown in Fig. 9 (1) (Fig. 11), and the horizontal placing shown in Fig. 9 (2). The laser processing was performed (FIG. 12), and the magnitude of the rotation angle (that is, the positional deviation) of the four corner portions of the scan region 7 between them was compared.

In this case, as shown in FIG. 10, (1) the 1st galva of the longitudinal direction side of HOE spectral pattern 14a at the time of vertical positioning shown in (1) of FIG. On the longer side of the rotation angles θ1 and θ2 from the drive shaft direction (the X-axis direction in Fig. 10) of the furnace scanner and (2) the HOE spectral pattern 14b at the time of horizontal positioning shown in Fig. 9 (2). The rotation angles [theta] 1 and [theta] 2 from the direction orthogonal to the drive shaft direction (the X-axis direction in FIG. 10) of a 1st galvano scanner were calculated by changing the area of a scanning area | region (refer Table 1).

In Table 1, the change of the rotation angles (theta) 1 and (theta) 2 at the time of the vertical position and the horizontal position when the area of a scanning area is enlarged to 26 mm, 33 mm, 43 mm, 65 mm is shown. As can be understood from Table 1, the larger the scan area is, the larger the pattern rotation angle is, but it can be seen that the rotation angle is clearly suppressed at the time of vertical positioning. That is, when the side (shown in FIG. 11) which aligned the longitudinal direction side of a HOE spectral pattern in the direction parallel to the drive shaft direction of a 1st galvano scanner is aligned to the direction parallel to the direction perpendicular to a drive shaft (FIG. 12). Correctness of the above-mentioned examination result that the rotation angle is suppressed rather than the case shown in () is shown.

Thus, according to this Embodiment 1, in the laser processing apparatus which processes a several hole simultaneously using HOE, the longitudinal direction side of a HOE spectral pattern does not face the direction orthogonal to the drive shaft of a 1st galvano scanner. In order to face the drive shaft direction of the first galvano scanner, it is possible to improve the positional accuracy of the processing hole by a simple measure, preferably in parallel with the direction. This measure is practically realized by adjusting the placement position of the HOE (including the optical system if present), but can also be realized by adjusting the drive shaft direction of the first galvano scanner.

Embodiment 2.

It is a conceptual diagram explaining the principle of the laser processing method implemented in the laser processing apparatus which does not use HOE by Embodiment 2 of this invention. In the laser processing apparatus which performs a single hole processing without using HOE, as shown in FIG. 13, in the structure shown in FIG. 14, the mask 15 is attached to the input terminal of the 1st galvano scan mirror 2a. Then, the mask shape is transferred. In addition, although illustration is abbreviate | omitted in FIG. 13, as shown in FIG. 14, the 1st galvano scan mirror 2a is connected to the drive shaft of the 1st galvano scanner 3a. The second galvano scan mirror 2b is connected to the drive shaft of the second galvano scanner 3b.

In this case, especially in the case where the shape of the processing hole has a long direction and a short direction such as an ellipse or a square, the inclination occurs in each part of the scan area as described above, causing distortion in the transfer shape itself. Throw it away.

Therefore, similarly to the first embodiment, as the arrangement form of the mask 15 or the first galvano scanner 3a, the first galvano scanner is arranged in the longitudinal direction (direction to become the maximum length) of the mask transfer shape pattern. When the mask 15 or the first galvano scanner 3a is provided so as to face the drive shaft direction of (3a), preferably in a parallel direction, distortion caused in the long hole pattern 16 due to this inclination Can be minimized.

In addition, although there is no special optical system in FIG. 13 between the mask 15 and the galvano scan mirror 2a, an optical element is arrange | positioned between the mask 15 and the galvano scan mirror 2a. Even if the longitudinal direction side of the hole shape in the laser beam incident on the first galvano scan mirror 2a is in the direction of the drive shaft of the first galvano scanner, preferably in a parallel direction, If the mask 15 or the first galvano scanner is arranged, the same distortion reduction effect can be obtained.

In this way, according to this Embodiment 2, in the laser processing apparatus which performs a single long hole process without using HOE, the longitudinal direction side of the mask transfer shape pattern of a mask is the drive shaft direction side of a 1st galvano scanner. The distortion of the shape that occurs when processing a long hole shape other than a round hole shape such as an ellipse or a quadrangle can be reduced by a simple measure to be aligned in a parallel direction.

As can be understood from the above descriptions in the first and second embodiments, two galvano scanners in which a two-dimensional scanning laser beam irradiated to a workpiece for punching processing are arranged at a predetermined optical distance on a laser optical axis are used. In the laser processing to be produced, when the simultaneous processing of a plurality of holes or a single long hole processing are performed, the long axis and the short axis exist in the irradiation pattern to the work, so that the two laser beams of the two galvano scanners The laser beam incident on the mirror surface on which the first galvano scanner disposed on the laser light generating source side rotates is rotated, and the long axis direction in the irradiation pattern is the axial direction side of the drive shaft of the first galvano scanner. In order to improve the positioning accuracy of a plurality of processing holes to be processed simultaneously. , And it can be also suppressed low distortion generated in the elongated hole machining one days.

As mentioned above, the laser processing apparatus which concerns on this invention improves the positional precision of the process hole, when processing a several hole simultaneously using HOE, or performing a single long hole process without using HOE. It is useful for reducing occurrence distortion.

Claims (3)

A laser oscillator for emitting a laser beam, A set of galvano scanners which two-dimensionally scan the laser light emitted from the laser oscillator; And a f? Lens for condensing and irradiating the laser light scanned two-dimensionally by the set of galvano scanners on the workpiece, Among the one set of galvano scanners, the laser beam incident on the laser beam axis side on the laser oscillator side has the long axis direction side among the long and short axes present in the irradiation pattern. It is set so that it may face the axial direction side of the drive shaft of a said 1st galvano scanner. The laser processing apparatus characterized by the above-mentioned. The laser beam incident on the first galvano scanner is an output laser beam of laser spectroscopic means for spectroscopy the laser beam from the laser oscillator into a plurality of laser beams. The said longitudinal axis side is a longitudinal direction side in the spectral pattern of the laser beam spectroscopically by the said laser spectroscopy means, The laser processing apparatus characterized by the above-mentioned. The laser beam incident on the first galvano scanner is an output laser beam of a mask for shaping the laser beam from the laser oscillator into a desired cross-sectional shape. The said longitudinal axis side is a longitudinal direction side in the irradiation pattern of the laser beam shaped with the said mask, The laser processing apparatus characterized by the above-mentioned.

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