JP5528149B2 - Laser processing apparatus and laser processing method - Google Patents

Description

  The present invention relates to a laser processing apparatus including a laser oscillator that oscillates a laser beam, and an optical fiber that guides the laser beam oscillated from the laser oscillator and irradiates the laser beam to the outside from the end face, and the like. The present invention relates to a laser processing method using a simple laser processing apparatus.

  Conventionally, a fiber transmission light (laser light L transmitted by the optical fiber 25) is imaged by the processing optical system 90, and processing is performed by moving the processing optical system 90 relative to the processing substrate 60. Is known (see FIG. 11). When using such a method, in order to increase the processing width or increase the processing efficiency, the imaging size of the fiber transmission light is increased, the beam is expanded in the processing width direction with a cylindrical lens, etc. Techniques such as increasing the score have been used.

  However, in order to increase the imaging size of the fiber transmission light, it is necessary to change the core diameter of the optical fiber 25 and the imaging magnification of the imaging lens to a large one. Moreover, in the method using a cylindrical lens, it is necessary to replace with a cylindrical lens suitable for each according to a desired processing width. Furthermore, in the method of increasing the number of processing points, it is necessary to increase the number of processing optical systems after fiber transmission and the means for moving those processing optical systems.

  For this reason, the conventional method described above has problems such as a lot of time and effort to change the setup, and is impractical, or the number of parts increases and the price of the apparatus becomes expensive.

  In addition, a method is also known in which a plurality of processing points are formed using a split lens / DOE optical system and the like, and processing is performed by rotating them (see Patent Document 1). However, when the imaging beam shape is not circular, for example, rectangular, the processing pitch and processing width can be adjusted by rotating the split lens / DOE optical system and the like by the rotating unit 95 (FIG. 12A). ) (See (b)), the beam shape changes with respect to the processing progress direction PD, so that there is a problem that the linearity of the edge of the scribe line is impaired (see FIG. 12 (b)).

  As a solution to these problems, it is considered that the position of the end face of the optical fiber 25 is moved on a plane orthogonal to the optical axis of the imaging lens (imaging optical system) 17 using a plurality of fiber transmission lights. (See FIG. 13). However, when the laser beam L is imaged by the imaging lens 17, if the end faces of the plurality of optical fibers 25 are simply moved on a plane orthogonal to the optical axis of the imaging lens 17 (see FIG. 13), On the substantially planar substrate 60, the image is blurred due to the aberration. Further, the curvature of field is caused by the difference in imaging performance between the central portion and the peripheral portion of the imaging lens 17 (the imaging surface is not flat).

  Further, as shown in Patent Document 2, when a plurality of scribe lines are formed on the substrate to be processed 60, a plurality of laser irradiations are simultaneously performed to form a plurality of scribe lines at the same time, thereby improving productivity. Therefore, when the laser beam L is imaged by the imaging lens 17, the size of the imaging lens 17 becomes larger. For this reason, the inconvenience that the image formed on the processing substrate 60 is blurred due to the aberration becomes larger, and the curvature of field occurs due to the imaging performance difference between the central portion and the peripheral portion of the imaging lens 17. The inconvenience of becoming larger becomes larger.

Japanese Patent No. 3293136 JP 2007-048835 A

  The present invention has been made in consideration of such points, and prevents the curvature of field from occurring on the substrate to be processed due to the difference in imaging performance between the central portion and the peripheral portion of the imaging optical system. And it aims at providing the laser processing apparatus and laser processing method which can make the aberration by the imaging optical system of a laser beam small.

The laser processing apparatus according to the present invention comprises:
A holding unit for holding the substrate to be processed;
A laser oscillator that oscillates laser light;
An optical fiber that guides the laser light oscillated from the laser oscillator and irradiates the laser light to the outside from the end face;
A processing moving unit that moves at least one of the holding unit and the end face of the optical fiber along a processing progress direction; and
A fiber moving unit connected to the optical fiber and moving an end face of the optical fiber in a direction including a component orthogonal to the processing progress direction;
An imaging optical system that forms an image of the laser light irradiated from the end face of the optical fiber on the workpiece substrate;
The fiber moving unit moves the end face of the optical fiber while being separated from the imaging optical system by a distance for correcting the aberration of the laser light by the imaging optical system.

In the laser processing apparatus according to the present invention,
The fiber moving unit may move the end face of the optical fiber on a virtual plane that minimizes the aberration of laser light by the imaging optical system.

In the laser processing apparatus according to the present invention,
The fiber moving unit may move the end face of the optical fiber on a tangential plane at a point on a virtual plane where the aberration of the laser beam by the imaging optical system is minimized.

In the laser processing apparatus according to the present invention,
The point on the virtual plane may be a point corresponding to the initial position of the end face of the optical fiber.

In the laser processing apparatus according to the present invention,
The fiber moving unit is a stepped surface obtained by approximating the end surface of the optical fiber to a virtual surface that minimizes the aberration of laser light by the imaging optical system, and is orthogonal to the optical axis of the imaging optical system You may move on the surface including the surface to perform.

In the laser processing apparatus according to the present invention,
The stepped surface approximated to the virtual surface may include a surface extending in a direction perpendicular to the optical axis of the imaging optical system from an initial position of the end surface of the optical fiber.

In the laser processing apparatus according to the present invention,
There are a plurality of the optical fibers,
The fiber moving unit may move at least one end face of the optical fiber.

In the laser processing apparatus according to the present invention,
The fiber moving unit may move the optical fiber so that an axis orthogonal to the end face of the optical fiber is maintained in a state parallel to the optical axis of the imaging optical system.

The laser processing method according to the present invention comprises:
Positioning the end face of the optical fiber at an initial position;
The optical fiber guides the laser light oscillated from the laser oscillator and irradiates the laser light to the outside from the end face, and then forms the image on the substrate to be processed through the imaging optical system. A process,
In the step of positioning the end face of the optical fiber at the initial position, the end face of the optical fiber is positioned at a position separated from the imaging optical system by a distance for correcting the aberration of the laser beam by the imaging optical system.

In the laser processing method according to the present invention,
In the step of positioning the end face of the optical fiber at the initial position, the end face of the optical fiber is positioned at a position separated from the imaging optical system by a distance that minimizes the aberration of the laser beam by the imaging optical system. Also good.

The laser processing method according to the present invention comprises:
Further comprising the step of moving the end face of the optical fiber in a direction including a component orthogonal to the optical axis of the imaging optical system;
The end face of the optical fiber may be moved on a virtual plane where the aberration of the laser beam by the imaging optical system is minimized.

The laser processing method according to the present invention comprises:
Further comprising the step of moving the end face of the optical fiber in a direction including a component orthogonal to the optical axis of the imaging optical system;
The end face of the optical fiber may be moved on a tangential plane at a point on a virtual plane where the aberration of the laser beam by the imaging optical system is minimized.

The laser processing method according to the present invention comprises:
Further comprising the step of moving the end face of the optical fiber in a direction including a component orthogonal to the optical axis of the imaging optical system;
The end surface of the optical fiber is a stepped surface approximated to a virtual surface that minimizes the aberration of laser light by the imaging optical system, and includes a surface that is orthogonal to the optical axis of the imaging optical system May be moved.

  According to the present invention, the end face of the optical fiber can be moved away from the imaging optical system by a distance that corrects the aberration of the laser beam by the imaging optical system. It is possible to prevent the field curvature from occurring on the substrate to be processed due to the difference in imaging performance between the portion and the peripheral portion, and to reduce the aberration of the laser light due to the imaging optical system.

The side view which showed the structure of the laser processing apparatus by the 1st Embodiment of this invention. The upper top view which showed the structure in the fiber holding housing | casing of the laser processing apparatus by the 1st Embodiment of this invention. The side view which showed the structure in the fiber holding housing | casing of the laser processing apparatus by the 1st Embodiment of this invention. The perspective view which showed the aspect which processes a to-be-processed substrate with the laser processing apparatus by the 1st Embodiment of this invention. The front view which showed the movement aspect of the end surface of the optical fiber in the laser processing apparatus by the 1st Embodiment of this invention. The side sectional view showing the processing mode of the processed substrate in the 1st embodiment of the present invention. The side sectional view showing the layer composition of the substrate to be processed. The front view which showed the movement aspect of the end surface of the optical fiber in the laser processing apparatus by the 2nd Embodiment of this invention. The front view which showed the movement aspect of the end surface of the optical fiber in the laser processing apparatus by the 3rd Embodiment of this invention. The figure which showed the aspect which processes a to-be-processed substrate with the laser processing apparatus by the 3rd Embodiment of this invention. The perspective view which showed the aspect which processes a to-be-processed substrate by an example of the conventional laser processing apparatus. The upper top view which showed the aspect which processes a to-be-processed substrate by another example of the conventional laser processing apparatus. The front view which showed the aspect which moved the end surface of the optical fiber on the surface orthogonal to the optical axis of an imaging lens.

First Embodiment Hereinafter, a first embodiment of a laser processing apparatus according to the present invention will be described with reference to the drawings. Here, FIG. 1 to FIG. 7 are diagrams showing a first embodiment of the present invention.

  The laser processing apparatus of this embodiment is for processing a substrate to be processed 60 used in a solar cell having a glass substrate (substrate) 61 and thin films 62, 63, 64 disposed on the glass substrate 61. Yes (see FIG. 7). Among these, the thin film was provided on the transparent electrode film 62 provided on the glass substrate 61, the photoelectric conversion layer 63 including Si and the like provided on the transparent electrode film 62, and the photoelectric conversion layer 63. And a back metal electrode film 64.

  As shown in FIG. 1, the laser processing apparatus guides the laser beam L oscillated from the laser oscillator 21, the laser oscillator 21 that oscillates the laser beam L, the holding unit 1 that holds the substrate 60 to be processed, and A plurality (four in the present embodiment) of optical fibers 25 that irradiate laser light L from the end face to the outside, and a processing moving portion 35 that moves the end face of the optical fiber 25 along the processing progress direction PD (see FIG. 2). And a detection unit (see reference numerals 41, 42, and 43 in FIG. 4) for detecting the position of the end face of the optical fiber 25 with respect to the thin film, and connected to each of the plurality of optical fibers 25, based on information from the detection unit. The actuator (fiber moving unit) 10 (see FIG. 2) moves the end face of the optical fiber 25 in a direction orthogonal to the processing progress direction PD (a direction including a component orthogonal to the optical axis of the imaging lens 17 described later). ), And it is equipped with a.

  Among these, the end face of the optical fiber 25 is disposed in the fiber holding casing 11. And the end surface of the optical fiber 25 will be moved along the process advancing direction PD by the fiber moving housing | casing 11 being moved along the process advancing direction PD by the process moving part 35. FIG. As shown in FIG. 2, the actuator 10 is also arranged in the fiber holding casing 11, and the end face of the optical fiber 25 is moved in the fiber holding casing 11 by the actuator 10.

  In the present embodiment, the actuator 10 is used as the fiber moving unit. However, as the actuator 10, a piezoelectric element, a linear motor, a linear coil, a cylinder, or the like can be used. By the way, it is preferable that the fiber moving portion is made of a small size, a high operation response, and a high operation speed. Further, the end face of the fiber 25 may be manually moved without using the actuator 10, and in this case, for example, the end face of the fiber 25 is moved on a moving gantry (track) corresponding to a virtual plane V described later. Just do it.

  Further, as shown in FIG. 2, each of the actuators 10 is disposed at a position shifted from each other along the processing progress direction PD, and drives the end face of the optical fiber 25 in a direction orthogonal to the processing progress direction PD. Is configured to do.

  In the present embodiment, the end face of the optical fiber 25 is described using an aspect in which the end face of the optical fiber 25 is moved along the processing progress direction PD. However, the end face of the optical fiber 25 is moved relative to the substrate 60 to be processed. If it is, it will not be restricted to this. For example, the holding unit 1 may be moved along the processing progress direction PD, or both the holding unit 1 and the end face of the optical fiber 25 may be moved along the processing progress direction PD. In the present embodiment, the end face of the optical fiber 25 is described using an aspect in which the end face is moved in a direction orthogonal to the machining progress direction PD. However, as long as the movement direction includes a component orthogonal to the machining progress direction PD. However, it is not limited to this. For example, the aspect which moves the end surface of the optical fiber 25 in the diagonal direction with respect to the process progress direction PD may be sufficient.

  As shown in FIG. 4, the detection unit described above includes an imaging unit (data acquisition unit) 41 including a CCD camera that acquires an image of the thin film by imaging the thin film, and an image of the thin film captured by the imaging unit 41. An image processing unit (information processing unit) 42 that processes the image processing unit 42 and a determination unit 43 that determines the position of the end face of the optical fiber 25 with respect to the thin film based on the image processed by the image processing unit 42.

  As shown in FIG. 1, a condensing lens 22 for condensing the laser light L oscillated from the laser oscillator 21 is provided between the laser oscillator 21 and the optical fiber 25. As shown in FIG. 3, below the end face of each optical fiber 25, an imaging lens (imaging optical system) that forms an image of laser light L emitted from the end face of the optical fiber 25 on the substrate 60 to be processed. ) 17 is provided.

  Further, as shown in FIG. 2, a fiber drive control unit 20 is connected to the actuator 10. Then, the fiber drive control unit 20 calculates a distance for correcting the aberration of the laser light L by the imaging lens 17 as the distance from the end face of the optical fiber 25 to the imaging lens 17. Then, the fiber drive control unit 20 moves the end face of the optical fiber 25 by the actuator 10 while being separated from the imaging lens 17 by the distance.

  More specifically, the fiber drive control unit 20 calculates a virtual surface V that minimizes the aberration (particularly “field curvature”) of the laser light L by the imaging lens 17, and the virtual surface V is calculated by the actuator 10. The end face of the optical fiber 25 is moved above (see FIG. 5). Note that the virtual plane V in the present application inverts the curvature of field formed by the focal point of the laser light L that has passed through the imaging lens 17 in plane symmetry with respect to the plane orthogonal to the optical axis of the imaging lens 17. This means the surface formed.

  By the way, the fiber drive control unit 20 may calculate the virtual plane V in real time to move the end face of the optical fiber 25, or calculate and store the virtual plane V in advance, and the light based on the storage. The end face of the fiber 25 may be moved.

  Next, the operation of the present embodiment having such a configuration will be described.

  First, a substrate to be processed 60 having a glass substrate 61 and a transparent electrode film 62 disposed on the glass substrate 61 is prepared (see FIG. 6A). Thereafter, the substrate to be processed 60 is held by the holding unit 1. At this time, in the present embodiment, the substrate to be processed 60 is held by the holding unit 1 so that the transparent electrode film 62 is positioned below the glass substrate 61. However, the present invention is not limited to this, and the substrate to be processed 60 may be held by the holding unit 1 so that the transparent electrode film 62 is positioned above the glass substrate 61.

Next, laser light L is oscillated from the laser oscillator 21 (see FIG. 1). Then, after the laser light L has passed through the condenser lens 22, the laser light L is guided in a plurality (four in the present embodiment) of optical fibers 25. Thereafter, the laser beam L is irradiated to the outside from the end face of the optical fiber 25. Thereafter, the laser light L passes through the imaging lens 17 and forms an image on the transparent electrode film 62, so that the transparent electrode film 62 is processed (see FIG. 6B). At this time, the end face of the optical fiber 25 is moved along the processing progress direction PD by the processing moving unit 35. As a result, the transparent electrode film 62 is processed along the processing progress direction PD, and a plurality of transparent electrode films 62 are formed on the transparent electrode film 62. so that the TCO scribe lines 62 _T is formed.

  Next, a photoelectric conversion layer 63 containing Si or the like is formed on the transparent electrode film 62 provided on the glass substrate 61 by a film forming apparatus (see FIG. 6C). Thereafter, the laser beam L is again oscillated from the laser oscillator 21 (see FIG. 1). Then, the laser light L is guided through the plurality of optical fibers 25 after passing through the condenser lens 22. Thereafter, the laser beam L is irradiated to the outside from the end face of the optical fiber 25, and the photoelectric conversion layer 63 is processed.

At this time as well, the end face of the optical fiber 25 is moved along the processing progress direction PD by the processing moving unit 35, and as a result, the photoelectric conversion layer 63 is processed along the processing progress direction PD. so that the plurality of Si scribe line 63 _S is formed (see FIG. 6 (d)).

  Thus, when the photoelectric conversion layer 63 is processed along the processing progress direction PD, the following steps are performed in the present embodiment.

First, the determination unit 43 determines the positions of the already processed TCO scribe lines 62 _T (in the present embodiment, each of the four TCO scribe lines 62 _T ), and each corresponding to the TCO scribe line 62 _T. The position of the end face of the optical fiber 25 (in this embodiment, the end faces of the four optical fibers 25) is determined. Then, the actuator 10 moves each of the end faces of the plurality of optical fibers 25 in a direction orthogonal to the processing progress direction PD, so that the end faces of the respective optical fibers 25 correspond to the end faces of the optical fibers 25. Move along _T.

  Here, according to the present embodiment, the imaginary plane V that minimizes the aberration of the laser light L by the imaging lens 17 is calculated by the fiber drive control unit 20. Then, when each of the end faces of the plurality of optical fibers 25 is moved in a direction perpendicular to the processing progress direction PD, each of the end faces of these optical fibers 25 is minimized in the aberration of the laser light L by the imaging lens 17. It can be moved on the virtual plane V (see FIG. 5). For this reason, the aberration of the laser light L due to the imaging lens 17 can be minimized. Prior to moving each end face of the optical fiber 25 on the virtual plane V, each end face of the optical fiber 25 is positioned at an initial position on the virtual plane V.

  That is, when the end face of the optical fiber 25 is simply moved on a plane perpendicular to the optical axis of the imaging lens 17 (see FIG. 13), the image formed on the substrate 60 is blurred due to aberration. It will occur. On the other hand, according to the present embodiment, each of the end faces of the plurality of optical fibers 25 is moved on the virtual plane V where the aberration of the laser light L by the imaging lens 17 is minimized. It is possible to prevent the image formed on the substrate to be processed 60 from being blurred.

  Further, since each of the end faces of the plurality of optical fibers 25 can be positioned on the virtual plane V where the aberration of the laser light L by the imaging lens 17 is minimized, the connection between the central portion and the peripheral portion of the imaging lens 17 is possible. It is possible to prevent the field curvature from occurring on the workpiece substrate 60 due to the difference in image performance.

The photoelectric conversion layer 63 is processed and on the photoelectric conversion layer 63 Si scribe line 63 _S is formed, then, the film forming apparatus, the back surface metal electrode on the photoelectric conversion layer 63 provided on the transparent electrode film 62 A film 64 is formed (see FIG. 6E). Thereafter, the laser beam L is again oscillated from the laser oscillator 21. Then, the laser light L is guided through the plurality of optical fibers 25 after passing through the condenser lens 22. Thereafter, the laser beam L is irradiated to the outside from the end face of the optical fiber 25, and the photoelectric conversion layer 63 and the back surface metal electrode film 64 are processed (see FIG. 6F).

Also at this time, the end face of the optical fiber 25 is moved along the processing progress direction PD by the processing moving unit 35. As a result, the photoelectric conversion layer 63 and the back surface metal electrode film 64 are processed along the processing progress direction PD. , so that the photoelectric conversion layer 63 and the back metal electrode film 64 metals scribe line 64 _M is formed.

Incidentally, when this way photoelectric conversion layer 63 and the back metal electrode film 64 is processed along the processing direction of travel PD, in this embodiment, the same process as when forming the Si scribe line 63 _S is performed . This point is omitted since the contents overlapped with the description of the time of forming the Si scribe lines 63 _S, the description herein.

  By the way, in the above, it demonstrated using the imaging | photography part 41 which acquires the image of a thin film by image | photographing a thin film as a data acquisition part (refer FIG. 4). However, the present invention is not limited to this, and for example, a line sensor or a laser scan can be used as the data acquisition unit.

  In the above description, the actuator 10 is connected to each optical fiber 25 and each end face of the optical fiber 25 is moved in a direction orthogonal to the processing progress direction PD. However, the present invention is not limited to this. In addition, one of the plurality of optical fibers 25 is fixed without moving in the direction perpendicular to the processing progress direction PD with respect to the processing moving unit 35, and the optical fiber 25 fixed in this way A mode in which the optical fiber 25 is moved in a direction orthogonal to the processing progress direction PD may be used. In this case, the end face of the fixed optical fiber 25 is moved in a direction orthogonal to the processing progress direction PD by the movement of the processing moving unit 35.

  In the above description, the image forming lens 17 is composed of a single element. However, the present invention is not limited to this. The image forming lens 17 is composed of a plurality of lenses, and a laser is formed by the plurality of lenses. The light L may be imaged. In this case, in consideration of the configuration of the imaging lens 17, the fiber drive control unit 20 calculates the virtual plane V that minimizes the aberration of the laser light L from the imaging lens 17.

  By the way, when an aspect like this embodiment is not used, it is conceivable to perform physical optical correction by combining a plurality of imaging lenses. However, even when a plurality of imaging lenses are combined in this way, the level of aberration correction that can be achieved in this embodiment cannot be performed, and a combination of a plurality of lenses is very expensive. Device. On the other hand, according to the present embodiment, aberration correction can be performed with high accuracy, and the price of the apparatus can be kept low.

Further, according to the present embodiment, even when a plurality of scribe lines 62 _T , 63 _S , and 64 _M are formed at the same time, each laser beam can be obtained simply by moving the end face of the optical fiber 25 on the virtual plane V. Since the aberration of L can be corrected, the processing quality of the processed substrate 60 can be made uniform. Further, even in the proximity irradiation that increases the density of the integrated line composed of the scribe lines 62 _T , 63 _S , and 64 _M , it is possible to make the laser beams L close to each other without considering blurring or distortion of the spot of the laser light L.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment, the end face of the optical fiber 25 is moved on the virtual plane V that minimizes the aberration of the laser light L by the imaging lens 17. On the other hand, in the second embodiment, the end face of each optical fiber 25 is provided with a plurality of points (four in this embodiment) on the virtual plane V at which the aberration of the laser light L by the imaging lens 17 is minimized. It moves on the tangent plane at point). A point on the virtual plane V used when forming the tangent plane is a point corresponding to the initial position of the end face of the optical fiber 25. When a plurality of (four in this embodiment) tangent planes are generated, the end face of the optical fiber 25 is moved on the surface of the tangent plane closest to the imaging lens 17 ( (See FIG. 8). Other configurations are substantially the same as those of the first embodiment.

  In the second embodiment shown in FIG. 8, the same parts as those in the first embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals, and detailed description thereof is omitted.

  According to the present embodiment, the end face of the optical fiber 25 is contacted at a predetermined point on the virtual plane V (not along the virtual plane V that minimizes the aberration of the laser light L by the imaging lens 17). It can be moved on a plane. For this reason, although the aberration of the laser beam L by the imaging lens 17 cannot be reduced as accurately as the first embodiment, the aberration of the laser beam L by the imaging lens 17 can be reduced to some extent by simple control. it can. For this reason, according to this Embodiment, the laser processing apparatus which can make the aberration of the laser beam L small can be provided, restraining at low cost.

  In addition, although the same effect as 1st Embodiment can be show | played also by this Embodiment, since the content overlaps, description other than the main effects shown below is abbreviate | omitted.

  Also in the present embodiment, the fiber drive control unit 20 calculates the virtual plane V that minimizes the aberration of the laser light L by the imaging lens 17. Then, when each of the end faces of the plurality of optical fibers 25 is moved in a direction perpendicular to the processing progress direction PD, each of the end faces of these optical fibers 25 is minimized in the aberration of the laser light L by the imaging lens 17. It can be moved on a tangent plane at predetermined points (four points) on the virtual plane V (see FIG. 8). For this reason, the aberration by the imaging lens 17 of the laser beam L can be reduced.

  In addition, each of the end faces of the plurality of optical fibers 25 can be positioned on a tangent plane at predetermined points (four points) on the virtual plane V that minimizes the aberration of the laser light L by the imaging lens 17. Further, it is possible to prevent the field curvature from occurring on the substrate 60 due to the difference in the imaging performance between the central portion and the peripheral portion of the imaging lens 17.

  By the way, in this Embodiment, although demonstrated in the aspect using the tangent plane in four points on the virtual surface V, it is not restricted to this, You may use the tangent plane in three or less points, You may use the tangent plane in five or more points.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. In the first embodiment, the end face of the optical fiber 25 is moved on the virtual plane V that minimizes the aberration of the laser light L by the imaging lens 17. On the other hand, in the third embodiment, the actuator 10 is a stepped surface in which the end surface of the optical fiber 25 is approximated to the virtual surface V that minimizes the aberration of the laser light L by the imaging lens 17. Therefore, the image forming lens 17 is moved on a plane including a plane orthogonal to the optical axis. The stepped surface approximated to the virtual surface V includes a surface extending in a direction orthogonal to the optical axis of the imaging lens 17 from the initial position of the end surface of the optical fiber 25. Other configurations are substantially the same as those of the first embodiment.

  In the third embodiment shown in FIG. 9, the same parts as those in the first embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals, and detailed description thereof is omitted.

  According to the present embodiment, the end face of each optical fiber 25 (rather than being along the virtual plane V at which the aberration of the laser light L by the imaging lens 17 is minimized) of the laser light L by the imaging lens 17 It can be moved on a stepped surface approximated to the virtual surface V that minimizes the aberration, including a surface (two horizontal surfaces in the present embodiment) orthogonal to the optical axis of the imaging lens 17. . For this reason, although the aberration of the laser beam L by the imaging lens 17 cannot be reduced as accurately as the first embodiment, the aberration of the laser beam L by the imaging lens 17 can be reduced to some extent by simple control. it can. For this reason, according to this Embodiment, the laser processing apparatus which can make the aberration of the laser beam L small can be provided, restraining at low cost.

  In addition, although the same effect as 1st Embodiment can be show | played also by this Embodiment, since the content overlaps, description other than the main effects shown below is abbreviate | omitted.

  Also in the present embodiment, the fiber drive control unit 20 calculates the virtual plane V that minimizes the aberration of the laser light L by the imaging lens 17. Then, when each of the end faces of the plurality of optical fibers 25 is moved in a direction perpendicular to the processing progress direction PD, each of the end faces of these optical fibers 25 is minimized in the aberration of the laser light L by the imaging lens 17. It can be moved on a stepped surface approximated to the virtual surface V and including a surface (two horizontal surfaces in the present embodiment) perpendicular to the optical axis of the imaging lens 17 (see FIG. 9). . For this reason, the aberration by the imaging lens 17 of the laser beam L can be reduced.

  Further, each of the end faces of the plurality of optical fibers 25 is a stepped surface that approximates a virtual plane V that minimizes the aberration of the laser light L by the imaging lens 17 and is orthogonal to the optical axis of the imaging lens 17. Therefore, it is possible to prevent the curvature of field from occurring on the substrate to be processed 60 due to the difference in imaging performance between the central portion and the peripheral portion of the imaging lens 17.

  By the way, in the present embodiment, the aspect using the stepped surface including the two surfaces orthogonal to the optical axis of the imaging lens 17 has been described. However, the present invention is not limited to this, and the optical axis of the imaging lens 17 is not limited thereto. A stepped surface including three or more surfaces orthogonal to each other may be used.

Fourth Embodiment Next, a fourth embodiment of the present invention will be described with reference to FIG. In the first to third embodiments, the laser processing apparatus is used in such a manner that the new scribe lines 63 _S and 64 _M are aligned with the already processed scribe lines 62 _T and 63 _S. On the other hand, in the present embodiment, one thick laser beam L is formed by continuously linking laser beams L irradiated from the end faces of the plurality of optical fibers 25 in a direction orthogonal to the processing progress direction PD. The laser processing apparatus is used in such a manner that the width of the formed laser beam L is changed by changing the position of each optical fiber 25 in a direction orthogonal to the processing progress direction PD. Other configurations are substantially the same as those of the first to third embodiments.

  In the fourth embodiment shown in FIG. 10, the same parts as those in the first to third embodiments shown in FIGS. 1 to 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, one thick laser beam L is formed by continuously linking laser beams L irradiated from the end faces of the plurality of optical fibers 25 in a direction orthogonal to the processing progress direction PD. And the width | variety of the formed laser beam L can be changed by changing the position of each optical fiber 25 in the direction orthogonal to the process advancing direction PD. Thus, even when the positions of the end faces of the optical fibers 25 are close to each other as compared with the first to third embodiments, the moving distance of the end faces of the individual optical fibers 25 is large. In some cases, the effect of reducing the aberration can be expected, which is beneficial.

  In addition, according to this Embodiment, there can exist the following effects.

  Also in the present embodiment, the fiber drive control unit 20 calculates the virtual plane V that minimizes the aberration of the laser light L by the imaging lens 17. Then, when each of the end faces of the plurality of optical fibers 25 is moved in a direction perpendicular to the processing progress direction PD, each of the end faces of these optical fibers 25 is minimized in the aberration of the laser light L by the imaging lens 17. Moving on the virtual plane V (see FIG. 5), or moving on a tangential plane at a predetermined point on the virtual plane V that minimizes the aberration of the laser light L by the imaging lens 17 (see FIG. 8); It is moved on a stepped surface approximated to a virtual surface V that minimizes the aberration of the laser beam L by the imaging lens 17 and including a surface orthogonal to the optical axis of the imaging lens 17 (FIG. 9). See). For this reason, the aberration by the imaging lens 17 of the laser beam L can be reduced. Further, it is possible to prevent the field curvature from occurring on the substrate to be processed 60 due to the difference in imaging performance between the central portion and the peripheral portion of the imaging lens 17.

  In addition, according to the present embodiment, the width D of the laser light L can be freely changed by simply driving each of the actuators 10, so that the width D of the laser light L can be used without using a plurality of large devices. The laser processing apparatus having such a function can be manufactured at low cost.

  In addition, when using an embodiment in which the end face of the optical fiber 25 is rectangular instead of the optical fiber 25 having an end face having a circular shape, linearity of both edges of the scribe line formed on the thin film 62 can be realized. Yes (see FIG. 10). Note that it is not always necessary to make the end face of the optical fiber 25 rectangular, and the cross section of the laser light L is rectangular by using a mask, optically shaping, or scanning the laser light L. It can be a shape. However, by making the end face of the optical fiber 25 rectangular, it is beneficial because the cross section of the laser light L can be made rectangular without shielding or scanning the laser light L.

  By the way, in the case of using a method of rotating a split lens / DOE optical system as in Patent Document 1 and using an optical fiber 25 having a rectangular end face, in the processing progress direction PD. On the other hand, the beam shape changes, and the linearity of the edge of the scribe line is impaired (see FIG. 12B). On the other hand, according to the present embodiment, the linearity of the edge of the scribe line can be maintained even when the optical fiber 25 having a rectangular end face is used (see FIG. 10). The merit of using the optical fiber 25 composed of the end face can be fully utilized.

1 Holding part 10 Fiber moving part (actuator)
17 Imaging lens (imaging optical system)
20 Fiber drive control unit 21 Laser oscillator 25 Optical fiber 35 Processing movement unit 41 Imaging unit (data acquisition unit)
42 Image processing unit (information processing unit)
43 Judgment Unit 60 Substrate 61 Glass Substrate (Substrate)
62 Transparent electrode film (thin film)
62 _T TCO scribe line (processed line)
63 Photoelectric conversion layer (thin film)
63 _S Si scribe line (processed line)
64 Back side metal electrode film (thin film)
64 _M metal scribe line (processed line)
L Laser beam PD Processing direction V Virtual plane

Claims (12)

A holding unit for holding the substrate to be processed;
A laser oscillator that oscillates laser light;
An optical fiber that guides the laser light oscillated from the laser oscillator and irradiates the laser light to the outside from the end face;
A processing moving unit that moves at least one of the holding unit and the end face of the optical fiber along a processing progress direction; and
A fiber moving unit connected to the optical fiber and moving an end face of the optical fiber in a direction including a component orthogonal to the processing progress direction;
An imaging optical system that forms an image of the laser light irradiated from the end face of the optical fiber on the workpiece substrate;
The laser processing apparatus, wherein the fiber moving unit moves the end face of the optical fiber while being separated from the imaging optical system by a distance for correcting the aberration of the laser light by the imaging optical system.   The laser processing apparatus according to claim 1, wherein the fiber moving unit moves the end face of the optical fiber on a virtual plane that minimizes the aberration of the laser light by the imaging optical system. The fiber moving unit moves the end face of the optical fiber on a tangential plane at a point on a virtual plane where the aberration of the laser beam by the imaging optical system is minimized ,
The laser processing apparatus according to claim 1 , wherein the point on the virtual plane is a point corresponding to an initial position of an end face of the optical fiber .   The fiber moving unit is a stepped surface obtained by approximating the end surface of the optical fiber to a virtual surface that minimizes the aberration of laser light by the imaging optical system, and is orthogonal to the optical axis of the imaging optical system The laser processing apparatus according to claim 1, wherein the laser processing apparatus moves on a surface including a surface to be operated. The stepped surface which is approximated to a virtual plane, according to claim 4, characterized in that it comprises a surface extending in a direction perpendicular from the initial position of the end face of the optical fiber to the optical axis of the imaging optical system Laser processing equipment. There are a plurality of the optical fibers,
Said fiber moving unit, the laser machining apparatus according to any one of claims 1 to 5, characterized in that moving at least one end face of the optical fiber. The fiber moving unit moves the optical fiber so that an axis orthogonal to an end face of the optical fiber is maintained in a state parallel to the optical axis of the imaging optical system. The laser processing apparatus according to any one of 6 . Positioning the end face of the optical fiber at an initial position;
The optical fiber guides the laser light oscillated from the laser oscillator and irradiates the laser light to the outside from the end face, and then forms the image on the substrate to be processed through the imaging optical system. A process,
In the step of positioning the end face of the optical fiber at the initial position, the end face of the optical fiber is positioned at a position separated from the imaging optical system by a distance for correcting the aberration of the laser beam by the imaging optical system. A featured laser processing method. In the step of positioning the end face of the optical fiber at the initial position, the end face of the optical fiber is positioned at a position separated from the imaging optical system by a distance that minimizes the aberration of the laser beam by the imaging optical system. The laser processing method according to claim 8 . Further comprising the step of moving the end face of the optical fiber in a direction including a component orthogonal to the optical axis of the imaging optical system;
The laser processing method according to claim 9 , wherein the end face of the optical fiber is moved on a virtual plane that minimizes the aberration of the laser beam by the imaging optical system. Further comprising the step of moving the end face of the optical fiber in a direction including a component orthogonal to the optical axis of the imaging optical system;
The end face of the optical fiber is moved on a tangential plane at a point on a virtual plane where the aberration of the laser beam by the imaging optical system is minimized,
The laser irradiation method according to claim 9 , wherein the point on the virtual surface is a point corresponding to an initial position of an end face of the optical fiber . Further comprising the step of moving the end face of the optical fiber in a direction including a component orthogonal to the optical axis of the imaging optical system;
The end surface of the optical fiber is a stepped surface that approximates a virtual surface that minimizes the aberration of laser light by the imaging optical system, and includes a surface that is orthogonal to the optical axis of the imaging optical system. The laser processing method according to claim 9 , wherein the laser processing method is moved.

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