WO2012090520A1

WO2012090520A1 - Laser processing device and laser processing method

Info

Publication number: WO2012090520A1
Application number: PCT/JP2011/056718
Authority: WO
Inventors: 之夫久所; 鈴木　良和
Original assignee: オムロン株式会社
Priority date: 2010-12-27
Filing date: 2011-03-22
Publication date: 2012-07-05
Also published as: JP2012135808A; TW201236791A

Abstract

In order to irradiate approximately the same position, at a temporal difference, whilst simply scanning a spot by means of a plurality of laser lights: after image formation at an image formation position (P1a) by means of a lens (120a), a laser light (λa) is collimated by another lens (121a) and enters a two-wavelength mirror (123); after image formation at an image formation position (P1b) by means of a lens (120b), another laser light (λb) is collimated by another lens (121b), is reflected by a complete reflection mirror (122), and enters the two-wavelength mirror (123); then, the optical paths of the laser lights (λa, λb) are joined by the two-wavelength mirror (123), and image formation takes place at image formation positions (P2a, P2b) by means of a two-wavelength lens (124). A module (131), which houses a complete reflection mirror (119) and one of the lenses (120b), shifts in the direction perpendicular to the optical axis of the lens (120b) by means of a shift mechanism (132). The present invention can, for example, be applied to a laser processing device for processing a thin-film solar cell panel.

Description

Laser processing apparatus and laser processing method

The present invention relates to a laser processing apparatus and a laser processing method, and more particularly to a laser processing apparatus and a laser processing method using a plurality of types of laser light in parallel.

Conventionally, a laser processing apparatus has been proposed in which two types of laser beams having different wavelengths and the like are irradiated to a processing target with a predetermined time difference to improve processing accuracy (for example, see Patent Documents 1 and 2).

For example, in the invention described in Patent Document 1, the time difference in which each laser beam is irradiated to the object to be processed is changed by changing the length of the optical fiber through which each laser beam passes and adjusting the optical path length difference of the laser beam. Adjusted.

Further, in the invention described in Patent Document 2, the optical system of each laser beam is completely independent, and each laser beam is irradiated to the object by adjusting the timing of emitting the laser beam for each optical system. Time difference is adjusted.

JP, 2006-313858, A Unexamined-Japanese-Patent No. 2010-142829

By the way, for example, in the thin film removal process of a thin film solar cell panel, it is desired that time spots can be provided at substantially the same position and irradiation can be performed while scanning each spot by two types of laser light in a predetermined direction. There is.

However, in the invention described in Patent Document 1, it is necessary to change the length of the optical fiber in order to adjust the time difference of irradiating the laser light depending on the scanning speed of the laser light, which takes time and labor. Also, it is only possible to adjust the time difference within the range of pre-prepared optical fibers.

Further, in the invention described in Patent Document 2, since the optical system of each laser beam is completely independent, it is difficult to adjust so that the two types of laser beams are irradiated to substantially the same position.

The present invention has been made in view of such a situation, and it is possible to provide a time difference at substantially the same position and enable irradiation while scanning each spot by a plurality of laser beams in a predetermined direction. is there.

The laser processing apparatus according to the first aspect of the present invention is a laser processing apparatus for processing an object to be processed using at least a first laser beam and a second laser beam, through which the first laser beam passes. In a first imaging position on a first optical path, a first lens for imaging the first laser light, and a first laser light after the first imaging position on the first optical path A second lens for collimating, a third lens for imaging the second laser beam at a second imaging position on a second optical path through which the second laser beam passes, and a second optical path And a fourth lens for collimating the second laser beam after the second imaging position of the second lens, and the optical path of the first laser beam and the second laser beam at a stage subsequent to the second lens and the fourth lens. A coupling means for coupling the first laser light and the first laser light provided between the coupling means and the object to be processed; The fifth lens for forming the second laser beam and the second optical path are adjusted, and the optical axis of the third imaging position, which is the imaging position for the second laser beam by the fifth lens, is perpendicular And adjusting means for adjusting the position in any of the directions.

In the laser processing apparatus according to the first aspect of the present invention, the first laser beam forms an image at a first imaging position on the first optical path, and is collimated to form a second laser beam. After forming an image at a second imaging position on the optical path, it is collimated, and then the optical paths of the first laser light and the second laser light are combined, and then the first laser light and the second laser light Forms an image with the fifth lens. Further, the second light path through which the second laser light passes is adjusted, and the position of the image forming position of the second laser light by the fifth lens in the direction perpendicular to the optical axis is adjusted.

Therefore, by scanning each spot by a plurality of laser beams simply in a predetermined direction, it is possible to provide a time difference at substantially the same position for irradiation.

This coupling means is constituted by, for example, a two-wavelength mirror. The adjusting means is constituted by, for example, a shift mechanism or a rotation mechanism using an actuator or the like.

The adjustment means can adjust the position of the third imaging position in the direction perpendicular to the optical axis by adjusting the position of the second imaging position in the direction perpendicular to the optical axis.

Thus, by simply scanning the spots of the plurality of laser beams in a predetermined direction with a simple configuration, it is possible to provide a time difference at substantially the same position and perform irradiation.

In this laser processing apparatus, a first slit provided between a first lens and a second lens on a first light path, and a third slit and a fourth lens on a second light path And the second slit provided in the second slit, and adjusting the position of the opening of the second slit in the direction perpendicular to the optical axis of the second slit, The position in the vertical direction can be adjusted.

As a result, the edge of the spot of the laser light becomes sharp, and as a result, the processing quality is improved.

The second slit can be provided near the second imaging position, and the adjusting means can move the second imaging position together with the opening of the second slit.

Thereby, the loss of the laser beam by the slit can be reduced.

The laser processing apparatus further includes changing means for changing the direction of the second optical path to the direction of the coupling means at a stage subsequent to the fourth lens, and the adjusting means includes a fifth lens for the second optical path. The position of the third imaging position in the direction perpendicular to the optical axis can be adjusted by rotating it about the rotation axis that coincides with the optical axis of the third image.

Thus, the degree of freedom in adjusting the irradiation position of the second laser light spot can be increased.

The laser processing apparatus includes an optical fiber for transmitting the first laser beam and the second laser beam, and a sixth lens for collimating the first laser beam and the second laser beam emitted from the optical fiber. A separation means for separating the optical paths of the first laser light and the second laser light into the first optical path and the second optical path may be further provided downstream of the sixth lens.

Thereby, the intensity of the cross section of the laser beam can be made uniform, and as a result, the processing quality is improved.

This separation means is constituted by, for example, a two-wavelength mirror.

The shape of the output end face of the optical fiber can be made square.

Thereby, for example, the loss of the laser beam by the slit can be reduced.

The laser processing apparatus may further include scanning means for moving the third imaging position on the surface of the object to be processed.

This scanning means is realized, for example, by a galvano mirror which scans the imaging position on the surface of the processing object, an XY stage which moves the processing object, a gantry stage which moves the laser processing apparatus, or a combination thereof. Can.

The laser processing method according to the second aspect of the present invention is a laser processing method for processing an object to be processed using at least a first laser beam and a second laser beam, wherein the first laser beam and the second laser beam are used. Light is generated, and the first laser beam and the second laser beam are imaged in the same shape or different shape and adjacent to the surface of the object to be processed, and imaged in the direction in which the adjacent images are aligned The position is moved or the relative position of the object to be processed is moved to continuously process the surface of the object.

In the second aspect of the present invention, a first laser beam and a second laser beam are generated, and the first laser beam and the second laser beam have the same shape or different shapes, respectively, and the surface of the object to be processed. And the imaging position is moved in the side-by-side alignment direction of the adjacent imaging, or the relative position of the object to be processed is moved to continuously process the surface of the object.

Therefore, while scanning each spot by a plurality of laser beams easily, it is possible to provide a time difference at substantially the same position and to irradiate.

According to the first aspect of the present invention, by scanning each spot of a plurality of laser beams simply in a predetermined direction, it is possible to provide a time difference at substantially the same position and perform irradiation.

Further, according to the second aspect of the present invention, while scanning each spot by a plurality of laser beams easily, it is possible to provide a time difference at substantially the same position for irradiation.

It is a figure which shows 1st Embodiment of the laser processing apparatus to which this invention is applied. It is a figure for demonstrating the effect of this invention. It is a figure which shows the example of the relationship of the area of a laser spot. It is a figure which shows 2nd Embodiment of the laser processing apparatus to which this invention is applied. It is a figure which shows 3rd Embodiment of the laser processing apparatus to which this invention is applied. It is a figure for demonstrating the edge deletion of a thin film solar cell panel. It is a figure which shows the positional relationship of a laser spot. It is a figure which shows 4th Embodiment of the laser processing apparatus to which this invention is applied. It is a figure which shows the change of the irradiation position of a laser spot. It is a figure which shows 5th Embodiment of the laser processing apparatus to which this invention is applied.

Hereinafter, modes for carrying out the present invention (hereinafter, referred to as embodiments) will be described. The description will be made in the following order.
1. First embodiment (basic form)
2. Second embodiment (an example using an XY slit mechanism)
3. Third embodiment (an example in which only the XY slit mechanism is shifted)
4. Fourth embodiment (an example in which the optical path of the laser beam λb is rotated)
5. Modified example

<1. First embodiment>
[Configuration example of laser processing apparatus]
FIG. 1 is a view showing a first embodiment of a laser processing apparatus to which the present invention is applied.

Hereinafter, the traveling direction of the laser light is referred to as the z-axis direction, and predetermined directions perpendicular to the z-axis direction and orthogonal to each other are referred to as the x-axis direction and the y-axis direction.

The laser processing apparatus 101 includes

laser oscillators

111a and 111b,

beam expanders

112a and 112b, total reflection mirrors 113, a beam splitter 114, a two-wavelength (Dichroic) fiber coupling lens 115, an optical fiber 116, and two-wavelength (Dichroic) coupling. Image processing optical system lens 117, two-wavelength (Dichroic) mirror 118, total reflection mirror 119, imaging processing

optical system lens

120a, 120b, 121a, 121b, total reflection mirror 122, two-wavelength (Dichroic) mirror 123, and , And is configured to include a two-wavelength (Dichroic) combined processing optical lens 124.

Although each of the two-wavelength imaging and processing

optical system lenses

117 and 124 is illustrated as a single convex lens, it may be configured by a combination of a plurality of convex lenses and concave lenses. Similarly, although the image forming processing

optical system lenses

120a, 120b, 121a, and 121b are also illustrated as one convex lens, respectively, they may be configured by a combination of a plurality of convex lenses and concave lenses.

Hereinafter, the dual-wavelength imaging processing

optical system lenses

117 and 124 will be simply referred to as dual-

wavelength lenses

117 and 124, and the imaging processing

optical system lenses

120a, 120b, 121a and 121b will be simply referred to as

lenses

120a, 120b, It is called 121a and 121b.

The laser oscillator 111a is made of, for example, an Nd: YAG laser, and is pulsed with a predetermined wavelength λa (hereinafter referred to as “laser light λa” in synchronization with an emission signal Sa input from a control device (not shown). Oscillate) and emit. The beam diameter of the laser beam λa emitted from the laser oscillator 111 a is expanded by the beam expander 112 a and enters the beam splitter 114.

The laser oscillator 111b is made of, for example, an Nd: YAG laser, and is pulsed with a predetermined wavelength λb (hereinafter referred to as “laser light λb” in synchronization with an emission signal Sb input from a control device (not shown). Oscillate) and emit. The beam diameter of the laser beam λb emitted from the laser oscillator 111 b is expanded by the beam expander 112 b, and then reflected by the total reflection mirror 113 and enters the beam splitter 114.

Hereinafter, the wavelength λa is set to 1064 nm, which is the wavelength of the fundamental wave of the Nd: YAG laser, and the wavelength λb is set to 532 nm, which is the wavelength of the second harmonic (SHG) of the Nd: YAG laser The case will be described.

The beam splitter 114 has a characteristic of transmitting light of wavelength λa and reflecting light of wavelength λb. Therefore, the laser beam λa passes through the beam splitter 114, and the laser beam λb is reflected by the beam splitter 114, whereby the optical paths of the laser beam λa and the laser beam λb are coupled. Then, the laser light λa and the laser light λb are condensed by the two-wavelength fiber coupling lens 115, are incident on the optical fiber 116, and are transmitted.

The cross section of the emission end face 116A of the optical fiber 116 is a square, and the cross section B1 of the laser beams λa and λb emitted from the optical fiber 116 is a square with a width (length of one side) d1. Further, the intensity of the cross section B1 of the laser beams λa and λb is made substantially uniform. The laser beams λa and λb emitted from the optical fiber 116 are collimated by the two-wavelength lens 117 and enter the two-wavelength mirror 118.

The two-wavelength mirror 118 has a characteristic of transmitting light of wavelength λa and reflecting light of wavelength λb. Accordingly, the laser beam λa is transmitted through the two-wavelength mirror 118, and the laser beam λb is reflected by the two-wavelength mirror 118, whereby the optical paths of the laser beam λa and the laser beam λb are separated.

The laser beam λa transmitted through the two-wavelength mirror 118 forms an image at the imaging position P1a by the lens 120a. The width d2a of the image B2a of the laser beam λa (the image B2a of the emission end face 116A of the optical fiber 116 formed by the lens 120a) at the imaging position P1a is determined by the following equation (1).

D2a = d1 × (f2a / f1) (1)

F1 represents the focal length of the two-wavelength lens 117, and f2a represents the focal length of the lens 120a.

After that, the laser light λa is collimated by the lens 121a after the imaging position P1a and is incident on the two-wavelength mirror 123.

On the other hand, the laser beam λb reflected by the two-wavelength mirror 118 is further reflected by the total reflection mirror 119, and then forms an image at the imaging position P1b by the lens 120b. The width d2b of the image B2b of the laser beam λb (the image B2b of the emission end face 116A of the optical fiber 116 formed by the lens 120b) at the imaging position P1b is determined by the following equation (2).

D2b = d1 × (f2b / f1) (2)

F2b represents the focal length of the lens 120b.

Thereafter, the laser beam λb is collimated by the lens 121b after the imaging position P1b, is reflected by the total reflection mirror 122, and is incident on the two-wavelength mirror 123.

The two-wavelength mirror 123 has a characteristic of transmitting light of wavelength λa and reflecting light of wavelength λb. Accordingly, the laser beam λa is transmitted through the two-wavelength mirror 123, and the laser beam λb is reflected by the two-wavelength mirror 123, whereby the optical paths of the laser beam λa and the laser beam λb are coupled.

Thereafter, the laser light λa and the laser light λb are imaged at the imaging position P2a and the imaging position P2b, respectively, by the two-wavelength lens 124. Then, the processing surface of the object to be processed is placed in the vicinity of the imaging positions P2a and P2b, whereby an image B3a of the laser beam λa (hereinafter referred to as a laser spot B3a) in the vicinity of the imaging position P2a The processing of the object to be processed is performed by the image B3b of the laser beam λb (hereinafter referred to as a laser spot B3b) in the vicinity of P2b.

The width d3a of the laser spot B3a at the imaging position P2a and the width d3b of the laser spot B3b near the imaging position P2b can be obtained by the following equations (3) and (4), respectively.

d3a = d2a × (f4 / f3a)
= D 1 × (f 2 a · f 4 / f 1 · f 3 a) (3)
d3b = d2b × (f4 / f3b)
= D 1 × (f 2 b · f 4 / f 1 · f 3 b) (4)

F3a represents the focal length of the lens 121a, f3b represents the focal length of the lens 121b, and f4 represents the focal length of the two-wavelength lens 124.

Also, the total reflection mirror 119 and the lens 120 b are housed in one module 131. The module 131 can be electrically or manually shifted in a predetermined direction perpendicular to the optical axis of the lens 120 b by, for example, a shift mechanism 132 configured by an actuator or the like. Hereinafter, the shift direction of the module 131 will be described as being coincident with the x-axis direction.

Then, as the module 131 shifts in the x-axis direction, the total reflection mirror 119 and the lens 120 b shift in the x-axis direction. Along with this, the optical path of the laser beam λb and the imaging position P1b shift in the x-axis direction, and as a result, the imaging position P2b of the laser beam λb (irradiation position of the laser spot B3b) is perpendicular to the optical axis of the lens 124 Shift in the right direction.

For example, assuming that the imaging magnification from the output end face 116A of the optical fiber 116 to the imaging position P1b is RM1 and the imaging magnification from the imaging position P1b to the imaging position P2b is RM2, the movement of the module 131 in the x-axis direction The moving distance D of the imaging position P2b with respect to the distance d is determined by the following equation (5).

D = d x RM1 x RM2 (5)

Since RM1 = f2b × f1 and RM2 = f4 × f3b, the equation (5) can be transformed into the following equation (6).

D = (d · f 2 b · f 3 b) / (f 1 · f 4) (6)

In the case of the example of FIG. 1, the imaging position P2b is shifted in the direction opposite to the moving direction of the module 131.

[Description of the effect of the present invention]
Therefore, the irradiation position of the laser spot B3b can be easily adjusted independently of the laser spot B3a, and the laser spot B3a and the laser spot B3b can be irradiated to different positions.

As a result, it is possible to easily realize that the laser spots B3a and B3b are scanned in the predetermined direction and the time difference is provided at substantially the same position. This point will be described with reference to FIG. 2 as an example in which the laser spots B3a and B3b are scanned in the direction of the arrow A1 and the laser spots B3b and the laser spots B3a are sequentially provided with a time difference as an example. .

For example, when the laser spot B3b and the laser spot B3a are irradiated at substantially the same position by providing a predetermined interval (time difference) between the emission timings of the laser beam λb and the laser beam λb, the scanning speed of the laser spot increases. In order to reduce the deviation of the irradiation position of the laser spot, it is necessary to shorten the interval of the emission timing (for example, about several tens to several hundreds ns). Therefore, in order to improve the accuracy of the emission timing interval, it is necessary to perform advanced and stable control, and the necessary cost increases.

On the other hand, in the laser processing apparatus 101, by adjusting the position of the module 131 in the x-axis direction, the laser spot B3b and the laser spot B3a are adjacent to each other in the scanning direction, as shown in the upper diagram of FIG. Can be irradiated. Then, by controlling the laser beams λa and λb to be emitted at the same timing without providing a time difference, the laser spot B3a is almost exactly overlapped and irradiated at the next irradiation timing at the position irradiated with the laser spot B3b. It becomes possible.

As described above, the laser spots B3a and B3b are scanned at substantially the same position in the direction of the arrow A1 only by adjusting the position of the module 131 in the x-axis direction without controlling the emission timing of the laser light. Irradiation can be performed by providing a time difference in a predetermined order. As a result, the cost required for the apparatus can be reduced, and electrical control is unnecessary, and only hard adjustment is required, so that stable processing can be performed in the long run.

Furthermore, by stopping only the emission of the laser light λa at the first irradiation timing and stopping the emission of the laser light λb at the last irradiation timing, the laser spot B3a (1) at the right end and the laser at the left end in FIG. The irradiation of the spot B3b (n) can be stopped.
As a result, it becomes possible to sequentially overlap and irradiate the laser spot B3b and the laser spot B3a sequentially from the start position to the end position of the scan.

As described above, for example, when removing the thin film of the thin film solar cell panel, after removing the thin film of the predetermined layer by the laser spot B3b, removing the thin film of the different layer at the same position by the laser spot B3a It is possible to improve the processing quality.

Further, according to equations (3) and (4), the width d3a of the laser spot B3a is proportional to the focal length f2a of the lens 120a, and the width d3b of the laser spot B3a is proportional to the focal length f2b of the lens 120b. Therefore, in the laser processing apparatus 101, the sizes of the laser spot B3a and the laser spot B3b can be easily adjusted individually by replacing the lens 120a and the lens 120b.

For example, as described above with reference to FIG. 2, when the laser spot B3a is overlapped and irradiated with the laser spot B3b, the area of the laser spot B3b is made larger than the area of the laser spot B3a as shown in FIG. However, the processing quality may be improved.

For example, when the areas of the two are the same, a roll-up (swell like an embankment) occurs due to the thermal effect of the processing edge when irradiating the laser spot B3b, and sputtering is performed from this roll-up portion when irradiating the next laser spot B3a. May scatter in all directions. On the other hand, generation of spatter from this roll-up portion can be prevented by making the area of the laser spot B3b slightly larger than the area of the laser spot B3a.

The width W between the edge of the laser spot B3b and the edge of the laser spot B3a can be easily adjusted by changing at least one of the focal length f2a of the lens 120a and the focal length f2b of the lens 120b as described above. can do.

<2. Second embodiment>
[Configuration example of laser processing apparatus]
FIG. 4 is a view showing a second embodiment of a laser processing apparatus to which the present invention is applied. In addition, the same code | symbol is attached | subjected to the part corresponding to FIG. 1 in the figure, The description is abbreviate | omitted suitably.

In the laser processing apparatus 201 of FIG. 4, XY slit

mechanisms

211 a and 211 b are added to the laser processing apparatus 101 of FIG. 1, a module 231 is provided instead of the module 131, and a shift mechanism 232 is provided instead of the shift mechanism 132. It is a thing.

The XY slit mechanism 211a is installed so that the opening Oa substantially coincides with the imaging position P1a of the laser light λa. In addition, the XY slit mechanism 211a can adjust the width in the vertical and horizontal directions of the rectangular opening Oa individually, and shapes the cross section of the laser beam λa imaged by the lens 120a into the shape of the opening Oa. It is incident on 121a.

The XY slit mechanism 211b is installed so that the opening Ob substantially coincides with the imaging position P1b of the laser beam λb. In addition, the XY slit mechanism 211b can individually adjust the width in the vertical and horizontal directions of the rectangular opening Ob, and shapes the cross section of the laser light λb formed by the lens 120b into the shape of the opening Ob. It is incident on 121 b.

The module 231 is configured to store the total reflection mirror 119, the lens 120b, and the XY slit mechanism 211b.

The shift mechanism 232 is configured by, for example, an actuator or the like, and electrically or manually shifts the module 231 in a predetermined direction perpendicular to the optical axis of the lens 120b. Hereinafter, the shift direction of the module 231 will be described as being coincident with the x-axis direction.

Then, as the module 231 shifts in the x-axis direction, the total reflection mirror 119, the lens 120b, and the XY slit mechanism 211b shift in the x-axis direction. Along with this, the optical path of the laser beam λb and the opening Ob of the XY slit mechanism 211b shift in the x-axis direction, and the position of the laser beam λb passing through the XY slit mechanism 211b shifts in the x-axis direction.
At this time, the image forming position Pb1 (not shown) of the laser beam λb and the opening Ob of the XY slit mechanism 211b shift in the x-axis direction while substantially matching each other. As a result, the imaging position P2b of the laser beam λb (the irradiation position of the laser spot B3b) is shifted in the direction perpendicular to the optical axis of the lens 124. In the case of this example, the imaging position P2b is shifted in the direction opposite to the moving direction of the module 231 by the distance represented by the above-mentioned equation (6).

Therefore, similarly to the laser processing apparatus 101, the irradiation position of the laser spot B3b can be easily adjusted independently of the laser spot B3a, and the laser spot B3a and the laser spot B3b can be irradiated to different positions. .

Further, the edges of the laser spot B3a and the laser spot B3b become sharp and the processing edge becomes sharp. As a result, processing accuracy can be improved.

Furthermore, by adjusting the shape of the opening Oa of the XY slit mechanism 211a, the shape and size of the laser spot B3a can be easily adjusted without replacing the lens 120a. Similarly, by adjusting the shape of the opening Ob of the XY slit mechanism 211b, the shape and size of the laser spot B3b can be easily adjusted without replacing the lens 120b.

<3. Third embodiment>
[Configuration example of laser processing apparatus]
FIG. 5 is a view showing a third embodiment of the laser processing apparatus to which the present invention is applied. In addition, the same code | symbol is attached | subjected to the part corresponding to FIG. 4 in the figure, The description is abbreviate | omitted suitably.

The laser processing apparatus 301 of FIG. 5 is different from the laser processing apparatus 201 of FIG. 4 in that a shift mechanism 311 is added, and a lens 120 b ′ is provided instead of the lens 120 b. In addition, the total reflection mirror 119, the lens 120b ', and the XY slit mechanism 211b are not modularized, and the shift mechanism 232 is not provided.

The focal length f2b 'of the lens 120b' is set to a value larger than the focal length f2b 'of the lens 120b of FIG. In addition, the XY slit mechanism 211b is disposed before the focal position of the lens 120b '.

The shift mechanism 311 is configured of, for example, an actuator or the like, and electrically or manually shifts the XY slit mechanism 211b in directions perpendicular to the optical axis and orthogonal to each other. Hereinafter, the shift direction of the XY slit mechanism 211b will be described as being coincident with the x-axis direction and the y-axis direction.

Then, as the XY slit mechanism 211b shifts in the x-axis direction or y-axis direction, the laser light passing through the XY slit mechanism 211b shifts the opening Ob of the XY slit mechanism 211b in the x-axis direction or y-axis direction. The position of λb shifts in the x-axis or y-axis direction. As a result, the imaging position P2b of the laser beam λb (the irradiation position of the laser spot B3b) is shifted in the direction perpendicular to the optical axis of the lens 124. In the case of this example, the imaging position P2b is shifted in the direction opposite to the moving direction of the XY slit mechanism 211b by the distance represented by the above-mentioned equation (6).

Therefore, by adjusting the shift amount and the shift direction of the XY slit mechanism 211b, the irradiation position of the laser spot B3b with respect to the laser spot B3a can be set to an arbitrary direction within a predetermined distance range.

[Specific example of processing]
Here, with reference to FIG. 6 and FIG. 7, the case where edge deletion of the thin film solar cell panel 351 is performed using the laser processing apparatus 301 will be described. Note that edge deletion is performed in the order of arrow A11, arrow A12, arrow A13, and arrow A14. Further, as in the example of FIG. 2, it is assumed that the edge deletion is performed by irradiating the laser spot B3a after the irradiation of the laser spot B3b.

As described above, the irradiation position of the laser spot B3b with respect to the laser spot B3a can be set in an arbitrary direction. For example, as shown in FIG. 7, it is possible to irradiate the laser spot B3b to any of the regions D1 to D4 adjacent to the laser spot B3a along with the laser spot B3a.

Therefore, first, the position of the XY slit mechanism 211b is adjusted by the shift mechanism 311 so that the laser spot B3b is irradiated to the region D2, and edge deletion in the direction of the arrow A11 is performed. Next, the shift mechanism 311 adjusts the position of the XY slit mechanism 211b so that the laser spot B3b is irradiated to the region D3, and edge deletion in the direction of the arrow A12 is performed. Next, the position of the XY slit mechanism 211b is adjusted by the shift mechanism 311 so that the laser spot B3b is irradiated to the region D4, and edge deletion in the direction of the arrow A13 is performed. Finally, the position of the XY slit mechanism 211b is adjusted by the shift mechanism 311 so that the laser spot B3b is irradiated to the region D1, and edge deletion in the direction of the arrow A14 is performed.

Thereby, in the laser processing apparatus 301, while irradiating the thin film solar cell panel 351 with the laser spot B3a and the laser spot B3b simultaneously, both irradiation positions can be accurately overlapped in a predetermined order, and as a result, edge deletion Improve the quality of In addition, it is sufficient to adjust the position of the XY slit mechanism 211b at each corner of the thin film solar cell panel 351, so that the control is easy and the processing time can be shortened.

<4. Fourth embodiment>
[Configuration example of laser processing apparatus]
FIG. 8 is a view showing a fourth embodiment of the laser processing apparatus to which the present invention is applied. In addition, the same code | symbol is attached | subjected to the part corresponding to FIG. 4 in the figure, The description is abbreviate | omitted suitably.

The laser processing apparatus 401 of FIG. 8 is different from the laser processing apparatus 201 of FIG. 4 in that a shift mechanism 411 is added, a module 421 is provided instead of the module 231, and the shift mechanism 232 is eliminated.

The shift mechanism 411 is constituted by, for example, an actuator or the like, and electrically or manually shifts the XY slit mechanism 211b in a direction perpendicular to the optical axis of the lens 120b. Hereinafter, the shift direction of the XY slit mechanism 211b will be described as being coincident with the x-axis direction.

Further, a dual wavelength mirror 118, a total reflection mirror 119, a lens 120b, an XY slit mechanism 211b, a lens 121b, a total reflection mirror 122, a dual wavelength mirror 123, and a shift mechanism 411 are stored in the module 421. The module 421 can be rotated in the direction indicated by the arrow A21 about an axis of rotation that coincides with the optical axis of the lens 124. As a result, the optical path of the laser beam λb from the two-wavelength mirror 118 to the two-wavelength mirror 123 rotates about a rotation axis that coincides with the optical axis of the lens 124. As a result, the relative position of the laser spot B3a and the laser spot B3b can be rotated.

For example, by rotating the module 421 by 90 degrees in the upward direction of FIG. 8 around the rotation axis, the irradiation position of the laser spot B3 b with respect to the laser spot B3 a is 90 as shown in the upper to lower views of FIG. It can be rotated by degrees.

Therefore, if the module 421 can be rotated 180 degrees around the rotation axis, the combination of the shift direction of the XY slit mechanism 211b and the rotation direction of the module 421 makes it possible, within the range of a predetermined distance, like the laser processing apparatus 301. The irradiation position of the laser spot B3b with respect to the laser spot B3a can be set in any direction. If the module 421 can be rotated 90 degrees around the rotation axis, the combination of the shift direction of the XY slit mechanism 211b and the rotation direction of the module 421 makes the laser spot B3a as described above with reference to FIG. It becomes possible to irradiate the laser spot B3b to any of the regions D1 to D4 adjacent to the four sides.

Thereby, for example, similarly to the laser processing apparatus 301, edge deletion of the thin film solar cell panel 351 can be performed by the method described above with reference to FIG.

<5. Modified example>
Hereinafter, modifications of the embodiment of the present invention will be described.

[Modification 1]
In the embodiment of the present invention, for example, the laser light λa emitted from the laser oscillator 111a and the laser light λb emitted from the laser oscillator 111b are directly incident on the lens 120a or the lens 120b without coupling the optical path. It is also possible to do so. In this case, it is desirable that the beam diameter of the laser beam λa be expanded, the laser beam λa be collimated, and the intensity of the cross section of the laser beam λa be made uniform between the laser oscillator 111a and the lens 120a. For homogenizing the strength, for example, a homogenizer or a Callidescope can be used. The same applies to the portion between the laser oscillator 111b and the lens 120b.

[Modification 2]
Further, in the laser processing apparatus 101 of FIG. 1, the shift direction of the module 131 may be shifted in two or more directions (for example, the x-axis direction and the y-axis direction) perpendicular to the optical axis of the lens 120b. Thereby, as in the laser processing apparatus 301 of FIG. 5 and the laser processing apparatus 401 of FIG. 8, it becomes possible to set the irradiation position of the laser spot B3b to the laser spot B3a in an arbitrary direction.

[Modification 3]
Similarly, in the laser processing apparatus 201 of FIG. 4, the shift direction of the module 231 may be shifted in two or more directions (for example, the x-axis direction and the y-axis direction) perpendicular to the optical axis of the lens 120 b. . Thereby, as in the laser processing apparatus 301 of FIG. 5 and the laser processing apparatus 401 of FIG. 8, it becomes possible to set the irradiation position of the laser spot B3b to the laser spot B3a in an arbitrary direction.

[Modification 4]
The present invention can also be applied to the case of using laser light of three or more wavelengths. When laser light of three or more types of wavelengths is used, for example, after the laser light is emitted from the optical fiber 116, the optical path of each laser light is branched, and for each optical path, FIG. 1, FIG. 4, FIG. The same configuration as that on the optical path of the laser beam λa or the laser beam λb described above with reference to FIG. Thereafter, after combining the optical paths of the respective laser beams, the light may be incident on the two-wavelength lens 124. When three or more wavelengths are used, a multi-wavelength lens corresponding to the wavelength is used as the two-wavelength lens 124.

The optical paths of all the laser beams do not necessarily have to be branched individually, and the optical paths of a plurality of laser beams may be shared. For example, when three types of laser beams λa, λb, and λc are used, the laser beam λb may be branched and the optical paths of the laser beam λa and the laser beam λc may be made common.

[Modification 5]
In the above description, an example is shown in which laser beams of different wavelengths are emitted from different laser oscillators, but laser beams of different wavelengths may be emitted from one laser oscillator. In this case, for example, pulsed laser beams of different wavelengths are emitted from a single laser oscillator at a predetermined time interval in a predetermined order.

[Modification 6]
Furthermore, in the above description, an example is shown in which a plurality of types of laser beams having different wavelengths are used in parallel, but in the present invention, other elements (for example, polarization direction, energy, etc.) other than the wavelength The present invention can also be applied to the case of using a plurality of types of laser beams in parallel.

FIG. 10 is a view showing an embodiment of a laser processing apparatus in the case of using laser beams having different polarization directions. In addition, the same code | symbol is attached | subjected to the part corresponding to FIG. 1 in the figure, The description is abbreviate | omitted suitably.

Compared with the laser processing apparatus 101 of FIG. 1, the laser processing apparatus 501 of FIG. 10 includes

laser oscillators

111a and 111b, a beam splitter 114, a dual wavelength fiber coupling lens 115, an optical fiber 116, dual wavelength imaging processing optics.

Laser oscillators

511a and 511b, polarization beam splitter (PBS) 512, fiber coupling lens 513, polarization maintaining fiber, instead of the system lens 117, the two wavelength mirrors 118 and 123, and the two wavelength coupling processing optical system lens 124 (Polarization-maintaining AND Absorption-reducing (PANDA) fiber) 514, an imaging processing optical system lens 515, polarization beam splitters (PBS) 516 and 517, and a combined processing optical system lens 518.

In addition, the total reflection mirrors 113, 119, and 122 are configured by mirrors that can reflect approximately 100% of S-wave light.

Although the imaging processing

optical system lenses

515 and 518 are illustrated as one convex lens, respectively, they may be configured by a combination of a plurality of convex lenses and concave lenses.

In addition, hereinafter, the imaging processing

optical system lenses

515 and 518 will be simply referred to as

lenses

515 and 518.

The laser oscillator 511a is, for example, an Nd: YAG laser, and is synchronized with a pulse-shaped emission signal Sa input from a control device (not shown), and is a pulse-shaped laser beam of P wave of a predetermined wavelength (hereinafter referred to as The laser beam P is oscillated and emitted. The beam diameter of the laser beam P emitted from the laser oscillator 511 a is expanded by the beam expander 112 a and enters the polarization beam splitter 512.

The laser oscillator 511b is made of, for example, an Nd: YAG laser, and in synchronization with an emission signal Sb input from a control device (not shown), a pulse-shaped laser beam of S wave having the same wavelength as the laser beam P (hereinafter The laser beam is oscillated and emitted. The beam diameter of the laser beam S emitted from the laser oscillator 511 b is expanded by the beam expander 112 b, and then reflected by the total reflection mirror 113 and enters the polarization beam splitter 512.

Hereinafter, as shown in the figure, the polarization direction of the laser light P is the vertical direction of the paper surface, and the polarization direction of the laser light S is the vertical direction of the paper surface.

The polarization beam splitter 512 has a characteristic of transmitting P-wave light and reflecting S-wave light. Therefore, the laser beam P passes through the polarization beam splitter 512, and the laser beam S is reflected by the polarization beam splitter 512, whereby the optical paths of the laser beam P and the laser beam S are combined. Then, the laser light P and the laser light S are condensed by the fiber coupling lens 513, enter the polarization maintaining fiber 514, and are transmitted while maintaining the polarization direction as it is.

The cross section of the output end face 514A of the polarization maintaining fiber 514 is a square, and the cross section B1 of the laser light P and S emitted from the polarization maintaining fiber 514 is a square having a width (length of one side) d1. Further, the intensity of the cross section B1 of the laser beams P and S is substantially uniform. The laser beams P and S emitted from the polarization maintaining fiber 514 are collimated by the lens 515 and enter the polarization beam splitter 516.

The polarizing beam splitter 516 has characteristics of transmitting light of wavelength P and reflecting light of wavelength S. Therefore, the laser beam P is transmitted through the polarization beam splitter 516 and the laser beam S is reflected by the polarization beam splitter 516, whereby the optical paths of the laser beam P and the laser beam S are separated.

The laser beam P transmitted through the polarization beam splitter 516 is imaged at the imaging position P1a by the lens 120a. Further, the laser light P is collimated by the lens 121 a and enters the polarization beam splitter 517.

On the other hand, the laser beam S reflected by the polarization beam splitter 516 is further reflected by the total reflection mirror 119, and then forms an image at the imaging position P1b by the lens 120b.
Further, the laser light S is collimated by the lens 121 b, reflected by the total reflection mirror 122, and enters the polarization beam splitter 517.

The polarization beam splitter 517 has a characteristic of transmitting light of wavelength P and reflecting light of wavelength S. Accordingly, the laser beam P is transmitted through the polarization beam splitter 517 and the laser beam S is reflected by the polarization beam splitter 517, whereby the optical paths of the laser beam P and the laser beam S are combined.

Thereafter, the laser beam P and the laser beam S are imaged by the lens 518 at the imaging position P2a and the imaging position P2b, respectively. Then, the processing surface of the object to be processed is placed in the vicinity of the imaging positions P2a and P2b, whereby the image B3a (laser spot B3a) of the laser light P near the imaging position P2a and the laser in the vicinity of the imaging position P2b The processing of the object to be processed is performed by the image B3b of the light S (laser spot B3b).

Thus, as in the above-described embodiment, it is easy to irradiate the laser spots B3a and B3b having the same wavelength but different polarization directions while providing a time difference while scanning in the predetermined direction. It can be realized. Therefore, for example, it is possible to process at twice the speed with respect to a material capable of efficient processing with one type of wavelength.

The present invention is applicable not only to one type of element but also to parallel use of a plurality of types of laser light different in combination of a plurality of elements (for example, combination of wavelength and polarization direction). Is also possible.

[Modification 7]
Further, the means for separating or combining the optical path of the laser beam or changing the direction of the optical path of the laser beam is not limited to the above-described example, and various modifications are possible. For example, in addition to the above-described example, it is also possible to use a prism or a half mirror.

[Modification 8]
Furthermore, although the example which makes the shape of the opening part of XY slit mechanism into a rectangle was shown in the above description, it is also possible to make shapes other than a rectangle, for example, circular, an ellipse, etc. Also, in the above description, the output end face of the optical fiber 161 and the polarization maintaining fiber 514 is square, but it may be rectangular.

[Modification 9]
The scanning of the laser spots B3a and B3b can be performed, for example, by scanning the imaging positions P2a and P2b with a galvano mirror or the like, moving the object to be processed, moving the laser processing apparatus, or a combination thereof.

The embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 101

Laser processing apparatus

111a,

111b Laser oscillator

112a, 112b Beam expander 113 Total reflection mirror 114 Beam splitter 115 Two-wavelength fiber coupling lens 116 Optical fiber 117 Two-wavelength imaging processing optical system lens 118 Two-wavelength mirror 119 Total reflection Mirrors 120a to 121b, 120b 'Imaging processing optical system lens 122 total reflection mirror 123 two wavelength property mirror 124 two wavelength property coupling processing optical system lens 131 module 132 shift mechanism 201

laser processing apparatus

211a, 211b XY slit mechanism 231 module 232 shift Mechanism 301 Laser processing apparatus 311 Shift mechanism 401 Laser processing apparatus 411 Shift mechanism 421 Module 501

Laser processing apparatus

511a, 511b Laser oscillator 512 Polarizing beam splitter 513 Fiber coupling lens 514 Polarization maintaining fiber 515

Imaging processing lens

516, 517 Polarizing beam splitter 518 Coupling processing lens

Claims

In a laser processing apparatus for processing an object using at least a first laser beam and a second laser beam,
A first lens for imaging the first laser beam at a first imaging position on a first optical path through which the first laser beam passes;
A second lens that collimates the first laser beam after the first imaging position on the first optical path;
A third lens for imaging the second laser beam at a second imaging position on a second optical path through which the second laser beam passes;
A fourth lens that collimates the second laser beam after the second imaging position on the second optical path;
Coupling means for coupling optical paths of the first laser beam and the second laser beam at a stage subsequent to the second lens and the fourth lens;
A fifth lens provided between the coupling means and the object to be imaged and for imaging the first laser beam and the second laser beam;
An adjusting unit that adjusts the second optical path to adjust the position of the third imaging position, which is an imaging position of the second laser beam by the fifth lens, in a direction perpendicular to the optical axis of the third imaging position; Laser processing apparatus characterized by having.
The adjustment means adjusts the position of the third imaging position in the direction perpendicular to the optical axis by adjusting the position of the second imaging position in the direction perpendicular to the optical axis. The laser processing apparatus according to claim 1.
A first slit provided between the first lens and the second lens on the first light path;
And a second slit provided between the third lens and the fourth lens on the second light path,
The adjustment means adjusts the position of the third imaging position in the direction perpendicular to the optical axis by adjusting the position of the opening of the second slit in the direction perpendicular to the optical axis. The laser processing apparatus according to claim 1.
The second slit is provided near the second imaging position,
The laser processing apparatus according to claim 3, wherein the adjustment unit moves the second imaging position together with the opening of the second slit.
The rear end of the fourth lens further includes changing means for changing the direction of the second light path to the direction of the coupling means.
The adjusting means adjusts the position of the third imaging position in the direction perpendicular to the optical axis by rotating the second optical path about a rotation axis that coincides with the optical axis of the fifth lens. The laser processing apparatus according to claim 3, characterized in that:
An optical fiber for transmitting the first laser beam and the second laser beam;
A sixth lens for collimating the first laser beam and the second laser beam emitted from the optical fiber;
The light source device further comprises separation means for separating the optical paths of the first laser light and the second laser light into the first optical path and the second optical path at a stage subsequent to the sixth lens. The laser processing apparatus according to claim 1.
The laser processing apparatus according to claim 6, wherein a shape of an emission end face of the optical fiber is a square.
The laser processing apparatus according to claim 1, further comprising a scanning unit that moves the third imaging position on the surface of the processing target.
In a laser processing method for processing a workpiece using at least a first laser beam and a second laser beam,
Generating the first laser beam and the second laser beam;
Imaging the first laser beam and the second laser beam in the same shape or different shapes and adjacent to the surface of the object to be processed;
Moving the imaging position in the direction in which the adjacent imagings are aligned, or moving the relative position of the object to be processed;
The laser processing method characterized by processing the surface of a target object continuously.