JPWO2009069375A1 - Laser processing equipment - Google Patents

Abstract

Provided is a laser processing apparatus which can reduce the installation space and can rotate a substrate using a fixed table without using a table rotating mechanism. A position-fixed table in which a substrate mounting surface is formed of a porous member, and is provided with an adsorption mechanism that adsorbs the substrate through the porous member and a levitation mechanism that blows gas to the substrate through the porous member and floats. 40, a laser light source 10, a laser beam scanning optical system 20 that shapes the laser beam emitted from the laser light source into a laser beam having an elliptical cross section, guides it to the processing surface of the substrate, and scans the processing surface; Substrate guidance that guides the substrate by a movable abutting portion that contacts the substrate side surface of the floated substrate and moves the substrate side surface in the horizontal direction when positioning or moving the placed substrate. The mechanism 50 is provided, and the substrate is levitated and moved and rotated to a desired position while pushing the side surface of the substrate by the substrate guiding mechanism.

Description

The present invention relates to a laser processing apparatus for processing a substrate to be processed by scanning a laser beam.
In the laser processing in the present invention, thermal stress generated when laser heating is performed on a brittle material such as a glass substrate, sintered ceramics, single crystal silicon, a semiconductor wafer, and a ceramic substrate at a temperature below the softening point is used. Laser scribe processing and laser ablation processing in which a brittle material or other material is heated at a melting temperature or higher are included.

  2. Description of the Related Art Scanning laser processing apparatuses that perform processing by relatively moving the irradiation position of a laser beam on a substrate to be processed are used for processing a brittle material substrate such as a glass substrate.

In such a laser processing apparatus, the laser beam is emitted from the laser light source for the purpose of increasing the processing accuracy by narrowing the processing width by laser processing or increasing the heating efficiency and improving the scanning speed when heating. A laser beam (original beam) having a circular cross section is adjusted to be elliptical on the optical path so that an elliptical beam spot is formed on the processed surface of the substrate.
The shape of the laser beam or beam spot to be adjusted is not limited to the literal “oval shape”, but the processing accuracy and heating efficiency can be improved even if the beam spot is an ellipse or other elongated shape having a major axis direction. Can be increased. Therefore, here, an “elliptical” laser beam or beam spot includes a beam spot having a shape having a major axis such as an ellipse.

  As a method of forming an elliptical beam spot from an original beam having a circular cross section emitted from a laser light source, a method of forming a beam spot having a long axis using a lens optical system has been put into practical use. For example, it is disclosed that an original beam having a circular cross section is shaped into an elliptical laser beam by arranging a cylindrical lens and a condenser lens on the optical path of the laser beam (see, for example, Patent Document 1).

  In a laser processing apparatus that uses a laser beam whose shape of the beam spot irradiated on the substrate is an ellipse, scanning is performed with the major axis direction of the beam spot coinciding with the scanning direction (X direction). In this case, the major axis direction of the beam spot is the scanning axis direction (X direction) at the time of laser processing, and the direction perpendicular to this (Y direction) is the feed axis direction when moving the processing position in the lateral direction.

In such a laser processing apparatus, one of the following drive mechanisms is employed in order to scan the beam spot by moving the laser beam with respect to the substrate.
One is that the laser optical system is fixed so that the irradiation position of the laser beam does not move, the substrate is placed on a table, and the table is driven in a two-dimensional direction (translation direction (XY direction), rotation direction ( The movable table moves in the θ direction)), and the laser beam is scanned in the X direction (see, for example, Patent Document 1).
The other is that the movable table driven by the table driving mechanism can be moved in the one-dimensional direction (X direction) and the rotational direction (θ direction), and the irradiation position of the laser beam is the moving direction of the movable table (X direction). The laser beam is scanned so that it can be moved in a direction (Y direction) perpendicular to ().

FIG. 20 is a configuration diagram showing a conventional example of a crack forming apparatus 500 (laser scribing apparatus) which is one of scanning type laser processing apparatuses. In this apparatus, the irradiation position of the laser beam is fixed so as not to move, and the table is moved in a two-dimensional direction (XY direction) and a rotation direction (θ direction).
That is, a slide table 502 is provided that reciprocates in the front-rear direction (Y direction) of FIG. 20 along a pair of guide rails 503 and 504 arranged in parallel on the gantry 501. A screw screw 505 is disposed between the guide rails 503 and 504 in the front-rear direction. A stay 506 fixed to the slide table 502 is screwed to the screw screw 505, and the screw screw 505 is connected to a motor ( The slide table 502 is formed so as to reciprocate in the Y direction along the guide rails 503 and 504 by forward and reverse rotation (not shown).

  A horizontal base 507 is disposed on the slide table 502 so as to reciprocate in the left-right direction (X direction) in FIG. 20 along the guide rail 508. A screw screw 510a rotated by a motor 509 is threaded through a stay 510 fixed to the pedestal 507, and the pedestal 507 is moved along the guide rail 508 in the X direction by rotating forward and backward. Move back and forth.

  A rotation table 512 that is rotated by a rotation mechanism 511 is provided on the base 507, and the glass substrate G is attached to the rotation table 512 in a horizontal state. The rotation mechanism 511 is configured to rotate the rotation table 512 around a vertical axis, and is configured to be rotated at an arbitrary rotation angle with respect to the reference position. The substrate G is fixed to the rotary table 512 by, for example, a suction chuck.

  An optical holder 514 connected to the laser 513 is held on the frame 515 above the rotary table 512. As shown in FIG. 21, the optical holder 514 is provided with a lens optical system 514a (for example, a cylindrical lens) for irradiating the laser beam transmitted from the laser 513 onto the substrate G as an elliptical heating spot BS. ing. Also, below the lens optical system 514a, an adjustment lens 514b that enlarges and reduces the area of the heating spot BS by moving the focal position up and down is provided. When the heating spot BS is enlarged or reduced, the area irradiated on the substrate surface and the energy density change. For this reason, for example, when the heating spot BS is enlarged by the adjusting lens 514b, the output of the laser oscillator 513 is increased, and when the heating spot BS is reduced, the output of the laser oscillator 513 is adjusted to be decreased.

  A cooling nozzle 516 is provided in the vicinity of the optical holder 514 for spraying the coolant toward the position behind the heating spot to form a cooling spot, and for rapid generation of thermal stress by rapid cooling. Also good.

  A pair of CCD cameras 520 (521) are fixed on the upper left side of the crack forming apparatus 500. These are used for detecting the position of the substrate. That is, a pair of markers (alignment marks) serving as processing reference points are attached to the glass substrate G placed on the rotary table 512. The pair of CCD cameras 520 (521) has the rotary table 512 at the origin position. These markers are imaged in the restored state (the state where the rotary table 512 in FIG. 20 has been moved to the left end). In FIG. A, only the CCD camera 520 on the front side of the paper is shown, and the CCD camera 521 on the back side of the paper is not shown.

  While the image of the substrate G displayed by the CCD cameras 520 and 521 is monitored on a display unit 557 (described later), the slide table 502, the base 507, and the rotary table 512 are adjusted to align the substrate G. Is called. By completing the alignment, each point of the substrate G is associated with the coordinate system set in the crack forming apparatus 500.

  A cutter wheel 518 is attached above the rotary table 512 via a vertical movement adjustment mechanism 517. When the initial crack TR is formed at the edge of the glass substrate G, the cutter wheel 518 moves the pedestal 507 from the standby position in the X direction and lowers the cutter wheel 518 temporarily to return to the standby position. Use.

  Subsequently, a control system of the crack forming apparatus 500 will be described with reference to FIG. In the crack forming apparatus 500, a table driving unit 551 that drives a motor (such as a motor 509) for positioning the slide table 502 and the base 507, a laser 513 and an adjustment lens 514b of the optical holder 514 are driven for laser beam irradiation. In the case of providing the laser driving unit 552 and the cooling nozzle 516, the cooling nozzle driving unit 553 for spraying the refrigerant, the cutter driving unit 554 for positioning the cutter wheel 518 and adjusting the pressure contact force to the glass substrate G, and the CCD cameras 520 and 521 Each drive system of the camera drive unit 555 that performs imaging by the control is controlled by a control unit 550 configured by a computer (CPU).

  The control unit 550 is connected to an input unit 556 composed of an input device such as a keyboard and a mouse, and a display unit 557 composed of a display screen for performing various displays. Necessary messages are displayed on the display screen and necessary. Instructions and settings can be entered.

  Next, the operation of the crack forming apparatus 500 will be described. A glass substrate G is placed on the turntable 512. At this time, positioning is performed using the cameras 520 and 521. The crack formation device 500 stores the scheduled cutting line CL.

Subsequently, crack formation is started. When the process is started, the position data of the stored be cut line CL are read, the slide table 502 as the cutter wheel 518 approaches the starting point _{P 0,} the pedestal 507 (the turntable 512) is moved. Further, when the cutter wheel 518 is lowered, the base 507 (the rotary table 512) is driven so that the substrate end approaches the cutter wheel 518, whereby an initial crack TR is formed at the substrate end.

Subsequently, the slide table 502 and the pedestal 507 (rotary table 512) move so that the beam spot BS is positioned immediately before the initial crack TR. Thereafter, the laser 513 is oscillated and irradiated with a laser beam to form a beam spot BS, which is scanned along the scheduled cutting line CL from the starting point P ₀ to the end point P ₁ (by the cooling nozzle 516 as necessary). Scanned to follow the cooling spot).
By performing the above processing, a crack is formed along the planned dividing line CL.

  Generally, a laser processing apparatus having a table translation mechanism that moves a table on which a substrate is placed in a two-dimensional direction (XY direction) together with the substrate or a one-dimensional direction (X direction) Laser processing with excellent spot scanning stability and good reproducibility can be performed.

However, because the table needs to be moved, a space from the table movement start position to the movement end position is required, and the installation space of the entire apparatus is inevitably about twice as large as the apparatus in which the table is fixed (primary There is a tendency to increase by about 4 times (in the case of two-dimensional driving).
In particular, recently, the area of the substrate to be processed tends to increase as in the case of processing a glass substrate for a liquid crystal panel. Therefore, a larger installation space is required as the substrate area increases.

  Further, since the table weight is heavier than the weight of the substrate, the table translation mechanism that translates the table requires a large driving force, and a driving mechanism that generates a large driving force must be used.

In addition, when processing a glass substrate, a semiconductor wafer, or the like into a square shape (the processing direction of the substrate is the x direction and the y direction), it is orthogonal to the x direction after the first processing along the x direction of the substrate. In many cases, the second machining is performed along the y direction. In this case, when processing using an elliptical beam spot, it is necessary to change the direction of the major axis direction of the beam spot by 90 degrees from the x direction of the substrate to the y direction of the substrate. In addition to the drive mechanism, a rotary table mechanism that rotates the substrate is required.
If the rotary table mechanism is mounted on the translational drive mechanism, the table weight will increase further, and a drive mechanism that generates a larger driving force must be used.

Therefore, a laser cutting device (laser processing device) in which a two-dimensional (XY direction) translation mechanism is provided on the laser beam side without providing a translation mechanism on the table has been proposed (see Patent Document 3).
According to this, the entire laser optical system (refractive lens, focusing lens group) that shapes the laser light source and the beam shape into an ellipse is provided with a drive mechanism that moves in the scanning direction of the laser beam.
JP 2006-289388 A WO2003 / 026861 JP 2000-61677 A

  In place of the table translation mechanism, the laser processing apparatus having a translation mechanism for moving the laser light source and the entire laser optical system for shaping the laser beam into an ellipse in the scanning direction can reduce the installation space, and thus is compact. A device configuration can be obtained.

However, when processing a glass substrate, a semiconductor wafer, or the like into a square using an elliptical beam spot (the processing direction of the substrate is the x direction and the y direction), the direction of the major axis direction of the beam spot is set to In order to change from the x direction to the y direction of the substrate, some long axis adjustment mechanism for rotating the long axis of the laser beam must be mounted, the laser optical system becomes complicated, and this long axis adjustment mechanism is used as a laser light source. It is necessary to move it with a translation mechanism together with the laser optical system for shaping the ellipse.
In order to avoid this, it is conceivable to provide a table rotation mechanism to rotate the substrate side. When the table rotation mechanism is provided, the installation space is not greatly increased. However, a large driving force for rotating the table rotating mechanism is required.

Therefore, the present invention is a laser that can perform processing in two different directions (x direction and y direction) on the substrate with an elliptical laser beam using a fixed table that does not have a translation mechanism and a rotational movement mechanism. An object is to provide a processing apparatus.
Furthermore, an object of the present invention is to provide a laser processing apparatus having an apparatus configuration suitable for processing with an elliptical laser beam using a position-fixed table.
It is another object of the present invention to provide a laser processing apparatus that can rotate a substrate without using a table rotating mechanism.

  In order to solve the above problems, the laser processing apparatus of the present invention has a substrate mounting surface formed of a porous member, and an adsorption mechanism for adsorbing the substrate via the porous member and the substrate via the porous member. A position-fixed table provided with a levitation mechanism that blasts by blowing a gas, a laser light source, and a laser beam emitted from the laser light source is shaped into a laser beam having an elliptical cross section and guided to the processing surface of the substrate. The laser beam scanning optical system that scans along the long axis direction of the beam spot irradiated on the substrate and the substrate placed on the table are positioned or moved on the side surface of the substrate that has been levitated. A substrate guide mechanism is provided that guides the substrate by a movable contact portion that contacts and moves the substrate side surface in a horizontal direction against the table surface.

  According to the laser processing apparatus of the present invention, the position of the table is fixed, and the substrate is placed on the porous member serving as the substrate placement surface of the table. The method for placing the substrate on the table is not particularly limited. For example, a general substrate transport mechanism (for example, a robot arm) may be used. The substrate placed on the table is fixed to the table by operating the suction mechanism. In the laser beam scanning optical system, a laser beam emitted from a laser light source is shaped into a laser beam having an elliptical cross section, guided to a processed surface of the substrate, and along the long axis direction of the elliptical beam spot irradiated on the substrate. Scan the machined surface. The part scanned with the laser is locally heated and processed. Subsequently, when the substrate is translated, rotated, or positioned at a new processing location, the suction mechanism is stopped and the levitation mechanism is operated to lift the substrate. The substrate guiding mechanism contacts the substrate side surface of the substrate with the movable contact portion levitated, and moves (rotates, translates) by pressing the substrate side surface in a horizontal direction with respect to the table surface. As a result, only the substrate is guided to a desired position while the table is fixed. When the desired position is reached, the levitation mechanism is stopped, and the suction mechanism is activated and fixed. Then, laser processing is performed by scanning the laser beam again with the laser scanning optical system.

According to the present invention, the table is not provided with a table translation mechanism or a table rotation mechanism, and a table with a fixed position is used, so that a table drive mechanism that requires a large driving force is not required. Further, it is not necessary to move the table, and the installation space can be reduced.
Further, when the substrate is rotated, the substrate can be rotated and positioned by merely bringing the movable contact portion into contact with the side surface of the floating substrate and pressing it with a slight driving force.

The present invention can further take the following aspects.
In the above invention, the substrate guiding mechanism may be provided with a plurality of movable contact portions, and the movable contact portions may be arranged so as to sandwich the substrate.
According to this, since the substrate can be guided so as to sandwich the substrate between the plurality of movable contact portions, the floating substrate can be stably moved.
Specifically, when the substrate is square, it is preferable to dispose the movable contact portions at two locations (a pair) in the diagonal direction. When the substrate is circular, it is preferable to arrange two locations in the linear direction across the center, or three locations of 120 degrees each.

In this case, each movable abutting portion may be branched at a portion that abuts on the side surface of the substrate and abuts on the substrate at two locations.
According to this, it becomes easy to control the movement of the substrate in the translational direction and the rotation direction by contacting the side surface of the substrate at two adjacent points. In particular, in the case of a square substrate, translational and rotational movement of the rectangular substrate can be easily performed by contacting two adjacent sides across the corner of the substrate.

Further, the substrate guiding mechanism may include an arm having a joint portion for freely moving the movable contact portion in a horizontal direction on the table surface.
According to this, the movable contact portion can be freely moved by adjusting the joint portion of the arm, and the position of the substrate can be freely translated and rotated on the table.

  The laser beam scanning optical system shapes a laser beam emitted from a laser light source and emits a beam with a parallel beam and an elliptical section, or a beam with a non-parallel beam and an elliptical section, and a beam Adjusting the emission direction of the elliptical beam emitted from the shaping unit and, if this elliptical beam is a non-parallel beam, adjusting to the elliptical beam of the parallel beam and emitting the parallel beam emitted from the optical path adjustment unit A scanning mechanism comprising a scanning axis moving mirror that moves while reflecting an elliptical beam of light and scans an elliptical beam spot on the substrate, and a scanning axis guide mechanism that moves the scanning axis moving mirror along the long axis direction of the beam spot The laser light source and the beam shaping unit are installed independently of the scanning mechanism unit, and the beam shaping unit does not move when scanning the beam spot. Unishi may be.

  Here, as long as the beam shaping unit can form and emit a beam having an elliptical cross section, the shaping method is not particularly limited. For example, an elliptical beam may be formed by a method using a well-known lens optical system (a combination of a cylindrical lens, a refractive lens, and a focusing lens) as disclosed in Patent Documents 1 to 3 described above. Good. Further, an elliptical beam may be formed by using a rotating polygon mirror and a lens to repeatedly reflect the laser beam by a polygon mirror in a predetermined region and then shaping the laser beam (see, for example, JP-A-2005-288541). reference). As the elliptical beam obtained by these methods, an elliptical beam of a non-parallel light beam is emitted. The elliptical beam may be formed by a method using a parabolic mirror group described later. In this case, it is emitted as a parallel light beam.

According to this, a board | substrate is mounted on the table which does not have a drive mechanism. The laser beam emitted from the laser light source is incident on the beam shaping unit, shaped into an elliptical laser beam, and emitted to the optical path adjustment unit. The optical path adjustment unit adjusts the emission direction of the elliptical beam and emits it to the subsequent scanning mechanism unit. When the elliptical beam from the beam shaping unit is a parallel beam, the optical path adjustment unit emits the parallel beam as it is to the scanning mechanism unit, and when the elliptical beam from the beam shaping unit is a non-parallel beam, the parallel beam Then, the light is emitted toward the scanning axis moving mirror of the scanning mechanism. Then, the elliptical beam of the parallel light beam is made incident on the scanning axis moving mirror of the scanning mechanism unit. The scanning mechanism unit reflects an elliptical beam of parallel light flux with a scanning axis moving mirror to form an elliptical beam spot on the substrate. Then, the scanning axis moving mirror is moved by the scanning axis guide mechanism toward the long axis direction (also referred to as the scanning axis direction) of the beam spot. At this time, the scanning axis moving mirror moves while reflecting the elliptical beam of the parallel light beam emitted from the optical path adjusting unit. As a result, the elliptical beam spot formed on the substrate moves on the substrate following the movement of the scanning axis moving mirror. Since the elliptical beam incident on the scanning axis moving mirror is a parallel beam, a beam spot having the same shape and the same direction is formed on the substrate regardless of the position of the scanning axis moving mirror. In this way, the laser light source and the beam shaping unit are installed separately from the scanning mechanism unit, and only the scanning axis moving mirror moves when scanning the beam spot.
According to the present invention, since the beam spot is scanned by moving only the movable mirror, a small driving force is sufficient, the driving mechanism can be reduced, and high-speed movement is facilitated.
Furthermore, since the laser beam reflected by the moving mirror is an elliptical beam of parallel light flux, a beam spot of the same shape and size can be obtained wherever the moving mirror is moved by the scanning axis guide mechanism. Can be irradiated onto the substrate.
In addition, since the beam spot is incident on the substrate as a parallel light beam, the beam spot formed on the substrate surface has the same shape and the same size regardless of the thickness of the substrate. There is no need to adjust the position in the height direction.

In this case, the scanning mechanism unit further feeds a feed axis moving mirror that moves in a direction perpendicular to the long axis direction of the beam spot (also referred to as a feed axis direction) and the feed axis moving mirror perpendicular to the long axis direction of the beam spot. A feed axis guide mechanism that moves along the direction is provided, and the elliptical beam of the parallel light beam emitted from the optical path adjustment unit is reflected in the order of the feed axis moving mirror and the scanning axis moving mirror to form a beam spot on the substrate. May be.
According to this, it becomes possible to move the beam spot in the long axis direction (scanning axis direction) by the scanning axis moving mirror and to move in the direction orthogonal to this (feeding axis direction). Therefore, laser processing can be performed at an arbitrary position in the feed axis direction. In addition, after the first laser processing is performed by scanning the scanning axis moving mirror, the first laser processing is performed by moving the feed axis moving mirror and then performing the second laser processing by scanning the scanning axis moving mirror. A second laser processing line parallel to the processing line can be formed. Furthermore, by alternately repeating the scanning of the scanning axis moving mirror and the movement of the feeding axis moving mirror, parallel laser processing lines can be formed one after another.

The scanning axis guide mechanism includes a scanning axis guide rail for guiding the scanning axis moving mirror to move in the long axis direction of the beam spot, and a guide for moving the feed axis moving mirror in a direction perpendicular to the long axis direction of the beam spot. The scanning shaft guide rail may be connected to the feed shaft moving mirror so as to move integrally therewith.
According to this, the direction of reflection from the feed axis moving mirror to the scanning axis moving mirror is always constant, and the optical axis adjustment becomes easy.

The beam shaping unit includes a beam deformation unit including a pair of paraboloidal mirrors arranged so as to form a confocal point with each other, and one of the paraboloidal mirrors reduces the laser beam in one direction. Or, it is emitted to the other parabolic mirror while expanding, and the other parabolic mirror emits the incident laser beam as an elliptical laser beam having a short axis width or a long axis width. May be.
According to this, since the elliptical beam emitted from the beam shaping unit can be made into a parallel light beam, it is not necessary to adjust it to a parallel light beam by a subsequent optical path adjustment unit, and adjustment work for making a parallel light beam is easy. Become. Furthermore, the optical path adjustment unit only needs to adjust the emission direction using a plane mirror, and the elliptical beam can be guided to the scanning mechanism unit with a parallel light beam.

Also, two beam deformation units are provided, and one beam deformation unit is formed with a short axis formed by a pair of a first parabolic mirror and a second parabolic mirror arranged so as to form a first confocal point with each other. A beam deforming unit for forming a long axis composed of a pair of a third parabolic mirror and a fourth parabolic mirror arranged so as to form a second confocal with each other. A beam deformation unit is formed, and the short axis forming beam deformation unit is directed toward the second parabolic mirror while the first parabolic mirror reduces the laser beam emitted from the laser light source in the first direction. The second parabolic mirror shapes the incident laser beam into an elliptical laser beam of a parallel light flux with a short axis width, and emits the laser beam toward the long axis forming beam deformation unit. The forming beam deformation unit has a third parabolic mirror and a second parabolic mirror. The laser beam emitted from the mirror is emitted toward the fourth parabolic mirror while being expanded in a second direction orthogonal to the first direction, and the fourth parabolic mirror emits the incident laser beam. Alternatively, the light beam may be shaped into an elliptical beam of a parallel light beam having a short axis width and a long axis width determined.
According to this, the elliptical beam emitted from the beam shaping unit can be made into a parallel light flux, and the major axis width and the minor axis width can be adjusted independently. Further, it is not necessary to adjust the parallel light beam in the optical path adjustment unit in the subsequent stage, and the optical path adjustment unit can guide the elliptical beam to the scanning mechanism unit at the parallel light velocity only by adjusting the emission direction using a plane mirror.

In addition, multiple sets of parabolic mirrors with different optical constants are prepared for the beam deformation unit. When changing the cross-sectional shape of the elliptical beam of the parallel light beam that is emitted, the beam deformation unit is replaced for each pair of parabolic mirrors. You may make it do.
According to this, by exchanging the pair of paraboloid mirrors as a set, the cross-sectional shape of the elliptical beam emitted from the beam shaping unit can be changed and emitted as a parallel light beam.

In addition, the beam deformation unit is configured such that one of the paired parabolic mirrors is a fixed focus parabolic mirror whose mounting position is fixed, and the other parabolic mirror is a movable variable focus parabolic mirror. When the movable parabolic mirror is moved, the focal point may be changed at the same time to form a confocal point with the fixed parabolic mirror.
According to this, the shape of the elliptical beam emitted from the beam shaping unit can be changed by changing the mounting position of the movable parabolic mirror, and the focal point is simultaneously changed when the shape of the elliptical beam is changed. Can be emitted as a parallel light beam by forming a confocal point with a fixed focus parabolic mirror.

The variable-focus parabolic mirror includes a flexible parabolic mirror body that reflects a laser beam, a fixed spindle that supports one end of the parabolic mirror body and is fixed to a pedestal, and a parabolic mirror body. A movable support shaft that supports the other end of the fixed support shaft and that can be translated and rotated in a plane direction orthogonal to the axial direction of the fixed support shaft, and a translation drive mechanism and a rotation drive mechanism that drive the movable support shaft. It may be.
According to this, the focal point can be changed by operating the translational drive mechanism and the rotational drive mechanism that drive the movable support shaft to change the shape of the reflecting surface of the parabolic mirror.

  The optical path adjustment unit of the laser beam scanning optical system is a first elliptical beam in which the major axis direction of the elliptical beam emitted from the beam shaping unit is directed to the first direction, and the major axis direction of the elliptical beam is orthogonal to the first direction. A long-axis direction switching unit that selectively emits one of the second elliptical beams directed in the second direction, and the scanning mechanism of the laser beam scanning optical system includes a first beam emitted from the long-axis direction switching unit. Based on the elliptical beam or the second elliptical beam, the first elliptical beam spot or the first elliptical beam spot is formed on the substrate to form a second elliptical beam spot whose major axis direction is orthogonal to the first elliptical beam spot. The beam spot on the substrate may be moved along two directions of the major axis direction of the elliptical spot or the second elliptical spot.

According to the laser processing apparatus of the present invention, the elliptical beam shaped by the beam shaping unit is emitted toward the long axis direction switching unit. The major axis direction switching unit emits a first elliptical beam in which the major axis direction of the elliptical beam of the parallel light beam incident from the beam shaping unit is directed to the first direction, or a second direction orthogonal to the first direction. A second elliptical beam directed toward is emitted. Then, based on the first elliptical beam or the second elliptical beam emitted from the long axis direction switching unit, the first elliptical beam spot on the substrate, or the first beam spot whose first axis is orthogonal to the long axis direction. Two elliptical beam spots are formed.
Then, the scanning mechanism section is based on the first elliptic beam or the second elliptic beam emitted from the major axis direction switching section, and the first elliptic beam spot or the first beam spot on the substrate is the major axis direction. Are formed, and the beam spot on the substrate is moved along the long axis direction of the first elliptical spot or the long axis direction of the second elliptical spot. In this way, laser processing is performed in two orthogonal directions without rotating the table.
According to this, it is possible to perform processing in two directions orthogonal to each other with an elliptical beam spot without using a table rotating mechanism.

The major axis direction switching unit includes a first optical path in which an optical element is arranged so that the major axis direction of the elliptical beam emitted from the beam shaping unit faces the first direction, and the major axis direction of the elliptical beam is the first direction. A second optical path in which an optical element is arranged so as to be directed in a second direction orthogonal to the optical path, and an optical path switching mechanism that selects the traveling direction of the elliptical beam emitted from the beam shaping unit as either the first optical path or the second optical path; You may make it consist of.
According to this, the elliptical beam emitted from the beam shaping unit is selectively passed through either the first optical path or the second optical path by the optical path switching mechanism, and the elliptical beam is obtained by the optical element provided in each optical path. Can emit an elliptical beam whose major axis direction is directed to either the first direction or the second direction perpendicular thereto.

The optical path switching mechanism may be a movable mirror that is disposed on the optical path and switches the reflection direction. Here, the structure of the movable mirror is not particularly limited. For example, the reflection direction may be switched by rotating a mirror around the support shaft. Further, a movable mirror to be taken in and out of the optical path may be attached, and the mirror may be switched depending on the reflection direction when it is put on the optical path and the traveling direction when it is removed from the optical path.
According to this, the major axis direction of the elliptical beam can be easily switched by the operation of switching the optical path of the reflected light by the movable mirror.

The long axis direction switching unit includes an optical path matching mechanism in which the first optical path and the second optical path intersect on the emission side, and the first optical path and the second optical path are oriented in the same direction at the intersection region. The matching mechanism may selectively emit either the first elliptical beam that has passed through the first optical path or the second elliptical beam that has passed through the second optical path.
According to this, the first ellipse beam and the second ellipse beam emitted from the long axis direction switching unit are emitted to the subsequent laser optical system through one optical path, so that the laser optical system and the subsequent parts are configured by a common optical path. can do.

Further, the optical path matching mechanism may be composed of a movable mirror that is inserted into and removed from the intersecting region.
According to this, it is easy to selectively guide the first elliptical beam and the second elliptical beam to the optical path laser optical system by inserting and removing the movable mirror.

Further, the optical elements arranged in the first optical path and the second optical path may be composed of a plane mirror group.
Since the elliptical beam passing through the first optical path and the second optical path is a parallel light flux, two elliptical beams whose major axis directions are orthogonal to each other can be easily formed by bending a plurality of times with a plane mirror.

Further, two trigger mechanisms may be provided independently in which the cutting edge is directed in the major axis direction of the first beam spot and the major axis direction of the second beam spot, and an initial crack is formed in each direction.
According to this, an initial crack can be formed in two directions orthogonal to each other, and processing can be advanced in each direction from the initial crack in two directions.

In addition, the beam shaping unit may emit a plurality of small-diameter parallel light beams emitted from a plurality of laser light sources so that the column direction is substantially in the major axis direction by arranging them in parallel and in series.
According to this, the optical system for shaping the elliptical beam of the parallel light beam can be simplified.

1 is an overall configuration diagram of a laser processing apparatus LM1 that is an embodiment of the present invention. The figure which shows the structural example of the beam shaping part which radiate | emits an elliptical parallel beam. The figure which shows the adjustment method of the major axis length of an elliptical beam spot. The figure which shows the cross-section of a table. The figure which shows the structure of a board | substrate guidance mechanism. The block diagram which shows the control system of the laser processing apparatus LM1 of FIG. The whole block diagram of the laser processing apparatus LM2 which is other one Embodiment of this invention. The block diagram which shows the control system of the laser processing apparatus LM2 of FIG. The figure which shows the structural example of the beam shaping part which radiate | emits an elliptical parallel beam. The figure which shows the structure of the 2nd parabolic mirror which has a focus drive mechanism. The figure which showed the shape of the laser beam radiate | emitted when a position and a focus are changed about the 2nd parabolic mirror M2 and the 4th parabolic mirror M4. The figure which showed the shape of the laser beam radiate | emitted when a position and a focus are changed about the 2nd parabolic mirror M2 and the 4th parabolic mirror M4. The figure which showed the shape of the laser beam radiate | emitted when a position and a focus are changed about the 2nd parabolic mirror M2 and the 4th parabolic mirror M4. The whole block diagram of the laser processing apparatus LM3 which is one Embodiment of this invention. The block diagram which shows the control system of the laser processing apparatus LM3 of FIG. The perspective view which shows the structure of a long axis direction switching part. The figure which shows the structure when a long axis direction switching part is a 1st state, and the direction which an elliptical laser advances. The figure which shows the direction when a long axis direction switching part is a 2nd state, and the direction which an elliptical laser advances. Substantially elliptic beam irradiated onto the substrate by the laser processing apparatus LM3 of FIG. The figure which shows an example of the conventional laser processing apparatus (crack formation apparatus). The figure which shows the control system of the laser processing apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Laser light source 20 Laser scanning optical system 21, 21a Beam shaping part 22 Scanning mechanism part 23 Optical path adjustment part 25, 26 Guide rail 27 Adjuster 40 Table 41 Upper member (porous member)
46 Vacuum pump 47 Air source 50 Substrate guidance mechanism 60, 65 Trigger mechanism 71 M2 translation drive mechanism 72 M2 focus drive mechanism 72a Pedestal 72b Fixed support shaft 72c Parabolic mirror main body 72d Movable support shaft 72e Small table (for X movement)
72f Small table (for Y movement)
72g small table (for rotation)
73 U2 unit drive mechanism 74 M4 translation drive mechanism 75 M4 focus drive mechanism 88 Parabolic mirror drive unit U1, U2 Beam deformation units M1-M4 Parabolic mirrors M5, M6 Plane mirrors M7, M8 Moving mirrors (plane mirrors)
M7, M8 Planar moving mirror (laser beam optical system)
M11 Planar movable mirror (optical path switching mechanism)
M12, M13 Plane mirror (first optical path)
M14, M15 Plane mirror (second optical path)
M16 Planar movable mirror (optical path matching mechanism)
F ₁₂ , F ₃₄ confocal

  Hereinafter, embodiments of the present invention will be described with reference to the drawings mainly using a laser scribing apparatus for processing a glass substrate as an example. Note that the laser scribing apparatus of this embodiment can be used as it is as a laser ablation apparatus as long as the laser irradiation conditions are adjusted.

[Embodiment 1]
FIG. 1 is an overall configuration diagram of a laser processing apparatus LM1 according to an embodiment of the present invention. The laser processing apparatus LM1 mainly includes a laser light source 10, a laser scanning optical system 20, a table 40, a substrate guiding mechanism 50, and a trigger mechanism 60.

(Laser light source)
A CO ₂ laser is used for the laser light source 10. A CO laser or excimer laser may be used instead of the CO ₂ laser. A laser beam (original beam L0) having a circular cross section is emitted from the laser light source 10. In the case of laser ablation processing, a laser light source having a wavelength and energy density capable of melting and evaporating the substrate material is used.

(Laser scanning optical system)
The laser scanning optical system 20 is roughly classified into a beam shaping unit 21 that adjusts the cross-sectional shape of the laser beam, a scanning mechanism 22 that mainly moves (scans) the laser beam along the table surface (XY direction), and a beam shaping. The optical path adjustment unit 23 guides the laser beam emitted from the unit 21 to the scanning mechanism 22. Of the table surfaces, the X direction is the scanning axis direction (the scribing direction), and the Y direction is the feed axis direction.

  The beam shaping unit 21 will be described. The beam shaping unit 21 shapes the original beam emitted from the laser light source 10 into a parallel beam having an elliptical cross-sectional shape and a plurality of optical elements for adjusting the major axis diameter and minor axis diameter of the parallel beam. Consists of.

FIG. 2A is a diagram illustrating a configuration example of the beam shaping unit 21 that emits an elliptical parallel beam. The beam shaping unit 21 includes a first parabolic mirror (concave surface) M1, a second parabolic mirror (convex surface) M2, a third parabolic mirror M3 (convex surface), and a fourth parabolic mirror M4 (concave surface). 4 optical elements. Among the first parabolic mirror (concave) M1 and the second parabolic mirror (convex) M2, by matching the focal point of each other, are arranged so that the confocal F _12. These constitute the first beam deformation unit U1. The third parabolic mirror (convex) M3 and the focal point of each other match also the fourth parabolic mirror (concave) M4, are arranged so that the confocal F _34. These constitute the second beam deformation unit U2.

  The traveling direction of the laser beam from the first parabolic mirror (concave surface) M1 to the second parabolic mirror (convex surface) M2 is the XY plane direction, and the laser beam reflected by the second parabolic mirror M2 is the first one. The four parabolic mirrors M3 are directed so that the traveling direction of the laser beam from the third parabolic mirror (convex surface) M3 toward the fourth parabolic mirror (concave surface) M4 is the XZ plane. An object mirror is arranged in three dimensions.

With such an arrangement, the first parabolic mirror M1 reflects the original beam L0 (see FIG. 2B) having a circular cross section traveling in the X direction in the XY plane direction. At that time, the beam width in the Z direction remains the same, and the beam width in the Y direction travels while converging, and enters the second parabolic mirror M2. The second parabolic mirror M2, by are arranged so that the confocal F _12, when reflecting the laser beam focused in the Y direction, becomes again parallel beam L1 (see FIG. 2 (c)) , Proceeds toward the X direction. The beam width in the Z direction of the parallel beam L1 remains the original beam L0, and becomes a laser beam having an elliptical cross section in which the beam width in the Y direction is reduced.

  Further, when the parallel beam L1 travels and is reflected by the third parabolic mirror M3, the beam width in the Y direction remains unchanged, and the beam width travels in the XZ plane while expanding the beam width in the X direction. It enters the fourth parabolic mirror M4.

Fourth parabolic mirror M4, by are arranged so that the confocal F _34, when reflecting the laser beam to expand in the X direction, is again collimated beam L2 (see FIG. 2 (d)) , Proceeds toward the X direction. The beam width in the Z direction of the parallel beam L2 is larger than that of the original beam L0, and the beam width in the Y direction is a laser beam having a long major axis elliptical cross-section reduced in comparison with the original beam.

  Then, the parallel beam L2 having an elliptical cross-sectional shape shaped by the beam shaping unit 21 forms an elliptical beam spot BS on the substrate G via the optical path adjustment unit 23 and the scanning mechanism 22 in the subsequent stage. . Therefore, by adjusting the optical constants of these four parabolic mirrors M1 to M4, it is possible to form an elliptical beam spot of parallel light fluxes having a desired long axis width and short axis width.

  In this case, the optical constant of the parabolic mirror is adjusted for each first beam deformation unit (first parabolic mirror M1, second parabolic mirror M2) or second beam deformation unit U2 (third parabolic mirror M2). The parabolic mirror M3 and the fourth parabolic mirror M4) are exchanged, and when they are exchanged, a parallel beam is emitted so as to maintain a confocal relationship for each unit. For this reason, it is preferable to prepare a plurality of pairs of paraboloid mirrors to be confocal in advance.

  If the pair of paraboloid mirrors forming the unit does not form a confocal point, the optical path adjustment unit 23, which will be described later, is adjusted so that a parallel lens is formed by arranging a cylindrical lens or the like on the optical path. You can also

  In the beam shaping unit 21 described above, two (U1, U2) beam deformation units are used. When only the first beam deformation unit U1 is used, the original beam is reduced in one direction and a parallel beam L1 having a short axis width is emitted to the subsequent stage. Further, when only the second beam deformation unit U2 is used, a parallel beam having a long axis width determined by expanding the original beam in one direction is emitted to the subsequent stage.

  Next, the optical path adjustment unit 23 will be described. As shown in FIG. 1, the optical path adjustment unit 23 includes two plane mirrors M5 and M6. The plane mirror M5 bends the parallel beam L2 traveling in the X direction to form a parallel beam L3 traveling in the Z direction. Adjustment in the X direction with the scanning mechanism 22 is performed by adjusting the optical path length (distance between M4 and M5) of the parallel beam L2. The plane mirror M6 bends the parallel beam L3 traveling in the Z direction in the Y direction to form a parallel beam L4 traveling in the Y direction. The height (Z direction) with respect to the scanning mechanism 22 is adjusted by adjusting the optical path length (distance between M5 and M6) of the parallel beam L3. Further, by adjusting the optical path length (distance between M6 and M7) of the parallel beam L4 when the plane mirror M7 of the scanning mechanism described later is at the origin position (see FIG. 1), adjustment in the Y direction with the scanning mechanism 22 is performed. Is done.

  Further, in the optical path adjusting unit 23, when the laser beam emitted from the preceding beam shaping unit 21 is not a parallel beam, a lens for forming a parallel beam may be interposed on the optical path. Specifically, a parallel light beam is formed using a cylindrical lens, a concave lens, or a convex lens.

Next, the scanning mechanism 22 will be described. The scanning mechanism 22 includes a guide rail 25 whose axis is directed in the Y direction (feed axis direction), a plane mirror M7 (feed axis moving mirror) attached movably along the guide rail 25 by a drive mechanism (not shown), and a plane mirror A guide rail 26 fixed integrally with M7 and having an axis line oriented in the X direction (scanning axis direction), and a plane mirror M8 (scanning axis moving mirror) attached movably along the guide rail 26 by a drive mechanism (not shown). The angle adjustment adjuster 27 adjusts the mounting angle of the plane mirror M8 with respect to the horizontal direction (the mounting angle of the XZ plane).
In order to stabilize the guide rail 26, the guide rail 25 is provided with a parallel second guide rail on the opposite side across the table 40, and the two parallel guide rails 25 in the Y direction are used in the X direction. The guide rail 26 may be supported.

For convenience, the position of the guide rail 25 closest to the plane mirror M6 (see FIG. 1) is set as the origin position of the plane mirror M7. The angle of the plane mirror M7 is adjusted so that the parallel beam L4 from the plane mirror M6 is bent at the origin position and the parallel beam L5 is guided to the plane mirror M8. At this time, the parallel beam L4 travels in the Y direction, and the plane mirror M7 also moves in the Y direction along the guide rail 25. Therefore, even if the plane mirror M7 moves to any position on the guide rail 25, the parallel beam L4 The light is reflected by M7 and guided to the plane mirror M8.
The plane mirror M8 bends the parallel beam L5 to form a beam spot BS on the substrate G. At this time, the parallel beam L5 travels in the X direction, and the plane mirror M8 also moves in the X direction along the guide rail 26. Therefore, regardless of the position of the plane mirror M8 on the guide rail 26, the parallel beam L5 Reflected by M8, a beam spot BS having the same shape is formed on the substrate G. Moreover, the beam spot to be formed is always an elliptical beam spot whose major axis is directed in the X direction (scanning axis direction).

Then, by moving the plane mirror M8 in the X direction, the elliptical beam spot BS is scanned in the X direction with the long axis directed in the X direction.
When a plurality of scans are performed in parallel along the X direction, the movement in the Y direction by the plane mirror M7 and the movement (scanning) in the X direction by the plane mirror M8 are alternately performed.

  In the scanning mechanism 22, the movement in the X direction (scanning axis direction) and the movement in the Y direction (feeding axis direction) can be performed. For example, the number of scans to be laser processed in one direction of the substrate is one. In such a case, since there is little need to move in the Y direction, the plane mirror M7 may be a fixed mirror and only the plane mirror M8 may be moved in the X direction. In this case, the substrate position may be adjusted by a substrate guiding mechanism 50 described later.

  Next, adjustment of the beam spot BS by the adjuster 27 will be described. The shape of the beam spot BS can be adjusted mainly by changing the optical constant of the optical element of the beam shaping unit 21. However, when the major axis length of the beam spot BS is changed, the beam shaping unit 21 is left as it is. Thus, the adjustment can be performed by the adjuster 27. FIG. 3 is a diagram illustrating an adjustment state of the long axis length by the adjuster 27. By changing the mounting angle of the plane mirror M8 by the adjuster 27 and adjusting the incident angle of the parallel beam L5 to the substrate, the parallel beam L5 is obliquely incident on the substrate. As a result, the major axis length of the beam spot BS can be changed. Therefore, the adjuster 27 can be used as a simple beam length adjusting mechanism.

(table)
Next, the table 40 will be described. FIG. 4 is a view showing a cross-sectional structure of the table 40. The table 40 is made of a porous member, and is in close contact with the upper surface member 41 on which the substrate G (see FIG. 1) is placed and the upper surface member 41, and further has a bottom surface. The body 42 in which 42a is formed and the flow path 43 connected to the hollow space 42a are formed, and the hollow space 42a is depressurized via the Bragg 45 connected to the external flow path 44, the flow path 43, and the external flow path 44. It consists of a vacuum pump 46 and an air source 47 that sends pressurized air to the hollow space 42 a via the flow path 43 and the external flow path 44.
Among these, the hollow space 42 a, the flow path 43, the external flow path 44, and the vacuum pump 46 form an adsorption mechanism that adsorbs the substrate G to the upper surface member 41. Further, the hollow space 42 a, the flow path 43, the external flow path 44, and the air source 47 form a floating mechanism for floating the substrate G from the upper surface member 41.

In the table 40, the hollow space 42 a is decompressed by starting the vacuum pump 46 and opening the on-off valve with the substrate G placed on the upper surface member 41, and the upper surface member 41 of the porous member. The substrate G is adsorbed via
On the other hand, with the substrate G placed on the upper surface member 41, the open / close valve is opened and air is sent from the air source 47, so that the hollow space 42a is pressurized, and the upper surface member 41 of the porous member is moved. The pressurized air is ejected through the substrate G, and the substrate G is lifted. At this time, the movement of the substrate G is restricted by the substrate guiding mechanism 50 described later.

(Substrate guidance mechanism)
Next, the board | substrate guidance mechanism 50 is demonstrated. FIG. 5 is a view showing the structure of the substrate guiding mechanism 50. The substrate guiding mechanism 50 includes a pair of movable contact portions 51a and 51b attached in the vicinity of the diagonal corners 48a and 48b of the square table 40.
Each of the movable contact portions 51a and 51b has articulated arms 53a and 53b in which a translation operation and a turning operation are performed around the support shafts 52a and 52b by a driving mechanism (not shown). Metal contact members 54a and 54b that are turned by a drive mechanism (not shown) are attached to the tip portions of the multi-joint arms 53a and 53b. The abutting members 54a and 54b are attached so that their tips branch to the left and right, respectively, and the portion in contact with the substrate G has a cylindrical shape. The axial direction of this cylinder is oriented in the vertical direction.

  Therefore, when it is desired to move the substrate G in the X direction, the Y direction, or to rotate it, the air source 47 (FIG. 4) is actuated to float the substrate G, so that the substrate G is brought into contact with the contact member 54a, By pushing with 54b, the board | substrate G comes to move to a desired position, contacting the contact members 54a and 54b lightly. Further, by stopping the positions of the contact members 54a and 54b at desired positions, stopping the air source 47, and operating the vacuum pump 46, the substrate G can be attracted to the desired positions.

  In the case of the substrate G on which the alignment mark is formed, the alignment mark is photographed using the cameras 55a and 55b in which the mounting positions with respect to the coordinate system defined in the table 40 are measured in advance. The position of the substrate G can be automatically adjusted by calculating the amount of displacement of the substrate G from the current position, calculating the amount of movement, and moving it by the substrate guiding mechanism 50.

(Trigger mechanism)
Next, the trigger mechanism for initial crack formation will be described. Whether or not the trigger mechanism is attached is arbitrary, and when the trigger mechanism is not attached, for example, laser ablation processing can be used instead.
As shown in FIG. 1, the trigger mechanism 60 includes a cutter wheel 61, an elevating mechanism 62, and an articulated arm 63. The multi-joint arm 63 moves in the same manner as the multi-joint arms 53 a and 53 b of the board guiding mechanism 50. The cutting edge of the cutter hole 61 is directed in the X direction.
When forming the initial crack TR, the articulated arm 63 causes the cutter wheel 61 to be directly above the position where the initial crack is formed. Then, the initial crack TR is formed by temporarily lowering and pressing the cutter wheel 61 by the lifting mechanism 62.

(Control system)
Subsequently, a control system of the laser processing apparatus LM1 will be described. FIG. 6 is a block diagram showing a control system of the laser processing apparatus LM1. The laser processing apparatus LM1 includes a suction / levitation mechanism drive unit 81 that drives the suction mechanism and the floating mechanism of the table 40, a substrate guidance mechanism drive unit 82 that drives the movable contact portions 51a and 51b of the substrate guidance mechanism 50, and a trigger mechanism 60. A trigger mechanism driving unit 83 for driving the lifting mechanism 61 and the articulated arm 63, a scanning mechanism driving unit 84 for moving the plane mirrors M7 and M8 of the scanning mechanism 22, a laser driving unit 85 for irradiating a laser beam, and a cooling nozzle. When a cooling spot that follows the beam spot BS is formed, each drive system of the cooling nozzle driving unit 86 that sprays the refrigerant from the refrigerant nozzle and the camera driving unit 87 that performs imaging by the CCD cameras 55a and 55b is a computer (CPU). It is controlled by the control unit 80 constituted by

  The control unit 50 is connected to an input unit 91 including an input device such as a keyboard and a mouse, and a display unit 92 including a display screen for performing various displays, and necessary messages are displayed on the display screen and necessary. Instructions and settings can be entered.

(Operation example)
Next, a typical processing operation example by the laser processing apparatus LM1 will be described. Here, the case where the fixed glass substrate G in which the alignment mark was engraved is scribed in the first direction and the second direction orthogonal to each other will be described. For convenience of explanation, the first direction is the x direction of the glass substrate, the second direction is the y direction of the glass substrate, and when the alignment mark is used for positioning, the x direction matches the X direction of the laser scanning optical system. To do.

  When the glass substrate G is placed on the table 40, first, the substrate G is positioned using the substrate guiding mechanism 50. For positioning, the alignment marks on the substrate G are detected by the cameras 55a and 55b, and the amount of displacement is obtained. Subsequently, the movable contact portions 51 a and 51 b are driven to bring the contact members 54 a and 54 b closer to the substrate side surface of the substrate G. At the same time, the floating mechanism is operated to lift the substrate G from the table surface. At this time, the movement of the glass substrate G is restricted by the contacts (four locations) with the contact members 54a and 54b. Subsequently, the movable contact portions 51a and 51b are driven to move (translate and rotate) the substrate G in the horizontal direction and stop at a position where the amount of positional deviation becomes zero. Then, the floating mechanism is stopped and the suction mechanism is operated to fix the substrate G to the table surface. As a result, positioning is completed in a state where the x direction of the substrate G coincides with the X direction of the laser scanning optical system.

Subsequently, the trigger mechanism 60 is driven to create the initial crack TR at the scribe start position of the glass substrate G. Subsequently, the scanning mechanism unit 22 is driven to adjust the positions of the plane mirrors M7 and M8 so that the beam spot BS is outside the scribe start position of the substrate G. Subsequently, scribing is performed in the x direction of the glass substrate by moving (scanning) the plane mirror M8 in the X direction while irradiating the laser beam. When the scribe in the x direction is further repeated, the movement in the Y direction (laser stop) by the plane mirror M7 and the movement in the X direction (scanning) (laser irradiation) by the plane mirror M8 are alternately performed.
At this time, since the laser beam emitted from the optical path adjusting unit 23 is an elliptical beam of parallel light flux, the beam spot BS having the same shape is formed on the substrate G regardless of the position of the plane mirror M7 and the plane mirror M8. Can do.

When the scribing process of the glass substrate in the x direction is finished, the suction mechanism is stopped, and the floating mechanism is operated to lift the substrate G. Subsequently, the movable contact portions 51a and 51b are driven to rotate and move the substrate G in the horizontal direction, and the positioning is completed in a state where the y direction of the substrate coincides with the X direction of the laser scanning optical system. Subsequently, the scanning mechanism unit 22 is driven to perform scanning similar to the scribe processing in the x direction.
With the above operation, scribing in the x direction and the y direction is completed on the glass substrate G.

In this apparatus, since the position of the table 40 is fixed and it is not necessary to move the table 40, the installation space of the apparatus is only an area occupied by the table 40 and an area such as the scanning mechanism 22 arranged around the area. So it becomes a compact structure.
As for the driving mechanism, the scanning mechanism unit 22 and the substrate guiding mechanism 50 need only have a small driving force as compared with the driving mechanism that moves the heavy table 40.

[Embodiment 2]
Next, a second embodiment of the present invention will be described. FIG. 7 is an overall configuration diagram of the laser processing apparatus LM2 according to the second embodiment of the present invention, and FIG. 8 is a block diagram showing a control system of the laser processing apparatus LM2. Parts that are the same as those described in FIGS. 1 to 6 are denoted by the same reference numerals, and a part of the description is omitted. The laser processing apparatus LM2 uses laser processing in that a variable-focus parabolic mirror is movably attached, and a control unit 80a to which a parabolic mirror driving unit 88 for driving the parabolic mirror is added. This is a change from the device LM1.

FIG. 9 is a diagram illustrating a configuration example of the beam shaping unit 21a of the laser processing apparatus LM2.
The beam shaping unit 21a includes a first parabolic mirror (concave surface) M1, a second parabolic mirror (convex surface) M2, a third parabolic mirror M3 (convex surface), and a fourth parabolic mirror M4 (concave surface). It consists of four optical elements.

The first parabolic mirror (concave surface) M1 has a fixed position and a constant focal point. The second parabolic mirror (convex surface) M2 is provided with a drive mechanism 71 that is moved in the Y direction with respect to the first parabolic mirror M1 by a motor (not shown). Then, a first parabolic mirror M1 and the second parabolic mirror M2, by matching the focal point of each other, are arranged so that the confocal F _12. These constitute the first beam deformation unit U1. The second parabolic mirror M2 has a focus driving mechanism 72 that changes its focus.

10A and 10B are diagrams showing the configuration of the second parabolic mirror M2 having the focus driving mechanism 72. FIG. 10A is a perspective view thereof, and FIG. 10B is a plan view thereof. In the second parabolic mirror M2, a fixed support shaft 72b stands on a pedestal 72a, and one end of a parabolic mirror body 72c having flexibility is supported by the fixed support shaft 72b. The parabolic mirror main body 72c is formed of a metal plate (for example, a stainless steel plate) having a mirror-finished reflection surface. The other end of the parabolic mirror 72c is supported by a movable support shaft 72d. Below the movable support shaft 72d, a small table 72e provided on the pedestal 72a and movable in the X direction, a small table 72f provided on the small table 72e and movable in the Y direction, and a small table 72f A small table 72g that can be rotated left and right (θ rotation) is stacked, and a movable support shaft 72d is fixed to the small table 72g. These small tables are driven by a motor (not shown). Since the shape of the reflecting surface of the parabolic mirror main body 72c can be changed by adjusting the positions of the small tables 72e, 72f, 72g, the relationship between the position of the small table and the focal point is obtained in advance. Thus, the second parabolic mirror M2 can be formed into a desired parabolic shape.
When the position of the second parabolic mirror M2 is moved with respect to the first parabolic mirror M1, the parabolic shape is adjusted according to the amount of movement, and the two parabolic mirrors M1 and M2 are adjusted. , adjusted to be confocal _{F 12} to each other.

Next, the third parabolic mirror M3 and the fourth parabolic mirror M4 will be described. The third parabolic mirror M3 has a constant focal point. And the third parabolic mirror (convex) M3 and fourth parabolic mirror (concave) M4, to match the focal point of each other, are arranged so that the confocal F _34. These constitute the second beam deformation unit U2. The beam deformation unit U2 is provided with a drive mechanism 73 that moves the entire unit in the Y direction in conjunction with the movement of the second parabolic mirror M2 by a motor (not shown). Therefore, the laser beam emitted from the second parabolic mirror M2 is always incident on the third parabolic mirror M3 and further emitted on the fourth parabolic mirror M4. Further, the fourth parabolic mirror M4 is provided with a drive mechanism 74 that moves in the Z direction with respect to the third parabolic mirror M3, and is further provided with a focus drive mechanism 75 (75a to 75g). The specific configuration of the focus drive mechanism 75 (75a to 75g) is the same as the focus drive mechanism 72 of the second parabolic mirror described in FIG. 10 (75a to 75g correspond to each of 72a to 72g). Description is omitted.

  The traveling direction of the laser beam from the first parabolic mirror (concave surface) M1 to the second parabolic mirror (convex surface) M2 is the XY plane direction, and the laser beam reflected by the second parabolic mirror M2 is the first one. The four parabolic mirrors M3 are directed so that the traveling direction of the laser beam from the third parabolic mirror (convex surface) M3 toward the fourth parabolic mirror (concave surface) M4 is the XZ plane. An object mirror is arranged in three dimensions.

With such an arrangement, the first parabolic mirror M1 reflects the original beam L0 (see FIG. 9B) having a circular cross section traveling in the X direction in the XY plane direction. At that time, the beam width in the Z direction remains the same, and the beam width in the Y direction travels while converging, and enters the second parabolic mirror M2. Second parabolic mirror M2, by are arranged so that the confocal F _12, when reflecting the laser beam focused in the Y direction, becomes again parallel beam L1 (see FIG. 9 (c)) , Proceeds toward the X direction. The beam width in the Z direction of the parallel beam L1 remains the original beam L0, and becomes a laser beam having an elliptical cross section in which the beam width in the Y direction is reduced.

  Further, when the parallel beam L1 travels and is reflected by the third parabolic mirror M3, the beam width in the Y direction remains unchanged, and the beam width travels in the XZ plane while expanding the beam width in the X direction. It enters the fourth parabolic mirror M4.

Fourth parabolic mirror M4, by are arranged so that the confocal F _34, when reflecting the laser beam to expand in the X direction, is again collimated beam L2 (see FIG. 9 (d)) , Proceeds toward the X direction.
As a result, the beam width in the Z direction of the parallel beam L2 is expanded from the original beam L0 by the beam deforming unit U2, and the beam width in the Y direction is reduced by the beam deforming unit U1 from the original beam. The laser beam has a cross section.

Then, the parallel beam L2 having an elliptical cross-sectional shape shaped by the beam shaping unit 21a forms an elliptical beam spot BS on the substrate G via the optical path adjusting unit 23 and the scanning mechanism 22 in the subsequent stage. .
As described above, according to the laser processing apparatus LM2, instead of preparing a replacement parabolic mirror set, a variable focus parabolic mirror is used, so that the beam shape is changed in a relatively wide range. be able to.

FIGS. 11 to 13 are diagrams showing the shapes of laser beams emitted when the position and focus are changed for each of the second parabolic mirror M2 and the fourth parabolic mirror M4.
By adjusting the position and focus of the second parabolic mirror M2, the width in the Y direction changes so as to be reduced. Further, by adjusting the position and focus of the fourth parabolic mirror M4, the width in the Z direction is changed so as to be enlarged.

[Embodiment 3]
Next, a third embodiment of the present invention will be described.
FIG. 14 is an overall configuration diagram of a laser processing apparatus LM3 according to the third embodiment of the present invention, and FIG. 15 is a block diagram showing a control system of the laser processing apparatus LM3. Parts that are the same as those described in FIGS. 1 to 6 are denoted by the same reference numerals, and a part of the description is omitted.
In particular, the laser light source 10, the table 40, and the substrate guiding mechanism 50 are the same as those in FIG.
In the laser processing apparatus LM3, the long-axis direction switching unit 30 is provided in the optical path adjusting unit 23, and the control unit 80b to which the optical path switching mechanism driving unit 89 for controlling this is added is changed from the laser processing apparatus LM1. It is.

(Laser scanning optical system)
The laser scanning optical system 20 is roughly divided into a beam shaping unit 21 that adjusts the cross-sectional shape of the laser beam, a scanning mechanism 22 that mainly moves the laser beam along the table surface (XY direction), and a beam shaping unit 21. The optical path adjustment unit 23 guides the emitted laser beam to the scanning mechanism unit 22. The beam shaping unit 21 has the same configuration as that shown in FIG.

  The optical path adjustment unit 23 will be described. As shown in FIG. 14, the optical path adjustment unit 23 includes a long-axis direction switching unit 30 and a plane mirror M6, and is provided between the beam shaping unit 21 and the scanning mechanism 22. The optical path adjustment unit 23 performs optical path adjustment for guiding the elliptical beam to the scanning mechanism 22 and also performs adjustment to change the major axis direction of the laser beam.

  FIG. 16 is a perspective view illustrating a configuration of the long axis direction switching unit 30. FIG. 17 is a diagram showing the configuration when the major axis direction switching unit 30 is in the first state and the direction in which the elliptical beam travels (FIG. 17A is a plan view, and FIG. 17B is A in FIG. 17A). Sight). 18 is a diagram showing the configuration when the major axis direction switching unit 30 is in the second state and the direction in which the elliptical laser travels (FIG. 18 (a) is a plan view, and FIG. 18 (b) is FIG. 18 (a)). A view in FIG.

The long-axis direction switching unit 30 includes a plane mirror group (M11 to M16). The plane mirror M11 is a movable mirror that is rotated 90 degrees by a support shaft 31b that is rotated by a motor 31a, and is used as the optical path switching mechanism 31.
The plane mirror M16 is moved in the Y-axis direction by the slide mechanism 32. The plane mirror M16 is used as an optical path matching mechanism. The plane mirror M11 and the plane mirror M16 are interlocked so that the first position indicated by the solid line in FIGS. 16 and 17 and the second position indicated by the alternate long and short dash line in FIG. 16 and indicated by the solid line in FIG. 18 are switched. .

  When the plane mirror M11 is in the first position, the elliptical beam L2 traveling in the X direction from the beam shaping unit 21 is reflected in the Y direction by the plane mirror M11, reflected in the −Z direction by the plane mirror M12, and by the plane mirror M13. The reflection in the −Y direction and the reflection in the −Z direction by the plane mirror M16 are repeated, and the light travels to the plane mirror M6. At this time, an optical path through which the elliptical beam passes is defined as a first optical path.

  When the plane mirror M11 is in the second position, the elliptical beam L2 traveling in the X direction from the beam shaping unit 21 is reflected in the -Y direction by the plane mirror M11, reflected in the -X direction by the plane mirror M14, and the plane mirror M15. The reflection in the −Z direction is repeated and proceeds to the plane mirror M6. At this time, an optical path through which the elliptical beam passes is defined as a second optical path. The first optical path and the second optical path cross each other at the position of the plane mirror M16. When using an elliptical beam that has passed through the second optical path, the plane mirror M16 is removed from the optical path by the slide mechanism 32.

  The elliptical beam that has passed through the first optical path and the elliptical beam that has passed through the second optical path have the same cross-sectional shape and are shifted by 90 degrees in the major axis direction. Therefore, by selecting the optical path in the optical path switching mechanism 31, two types of elliptical beams whose major axis directions are orthogonal to each other can be selected and emitted.

  Further, as shown in FIG. 14, the major axis direction switching unit 30 bends the parallel beam L2 traveling in the X direction to form the parallel beam L3 traveling in the Z direction. By adjusting the optical path length (distance between M4 and M11) of the parallel beam L2, the position adjustment in the X direction with the scanning mechanism unit 22 is performed. Further, the plane mirror M6 bends the parallel beam L3 traveling in the −Z direction in the −Y direction to form a parallel beam L4 traveling in the −Y direction. By adjusting the optical path length (distance between M16 and M6) of the parallel beam L3, the height (Z direction) with respect to the scanning mechanism 22 is adjusted. Further, by adjusting the optical path length (distance between M6 and M7) of the parallel beam L4 when a plane mirror M7 of the scanning mechanism to be described later is at the origin position (see FIG. 14), the position in the Y direction with respect to the scanning mechanism 22 is adjusted. Adjustments are made.

  Next, the scanning mechanism 22 that scans the beam spot BS will be described. The scanning mechanism 22 is integrally fixed to the guide mirror 25 whose axis is directed in the Y direction, the plane mirror M7 that is movably attached along the guide rail 25 by a driving mechanism (not shown), and the axis is X direction. And a plane mirror M8 that is movably attached along the guide rail 26 by a drive mechanism (not shown). Of these, the plane mirror M7 and the plane mirror M8 constitute a laser optical system that forms a beam spot BS by irradiating the substrate with the elliptical beam emitted from the long-axis direction switching unit 30. The guide rails 25 and 26 and a driving mechanism (not shown) constitute a moving mechanism for moving the laser optical system. Note that the two guide rails 25 may be provided in parallel with the table 40 interposed therebetween, and the guide rail 26 may be supported so as to be movable from both sides.

  For convenience, the position of the guide rail 25 closest to the plane mirror M6 (see FIG. 1) is set as the origin position of the plane mirror M7. The angle of the plane mirror M7 is adjusted so that the parallel beam L4 from the plane mirror M6 is reflected at the origin position and the parallel beam L5 is guided to the plane mirror M8. At this time, the parallel beam L4 travels in the -Y direction. Since the plane mirror M7 moves in the Y direction along the guide rail 25, the parallel beam L4 is reflected by the plane mirror M7 and guided to the plane mirror M8 regardless of the position of the plane mirror M7 on the guide rail 25. .

  The plane mirror M8 reflects the parallel beam L5 and forms a beam spot BS on the substrate G. At this time, the parallel beam L5 travels in the -X direction. Since the plane mirror M8 moves in the X direction along the guide rail 26, the parallel beam L5 is reflected by the plane mirror M8 and has the same shape on the substrate G regardless of the position of the plane mirror M8 on the guide rail 26. A beam spot BS is formed.

  The major axis direction of the beam spot formed on the substrate faces the Y direction when the major axis direction switching unit 30 selects the first optical path. Further, when the second optical path is selected, it faces in the X direction. Therefore, when the plane mirror M8 is moved (scanned) in the X direction, the scanning direction and the major axis direction can be matched by selecting the second optical path. Further, when the plane mirror M8 is moved (scanned) in the Y direction, the scanning direction and the major axis direction can be matched by selecting the first optical path.

(Trigger mechanism)
Since the trigger mechanism 60 of the present embodiment has the same configuration as that shown in FIG. 1, the description of the configuration is omitted.
In the present embodiment, in addition to the trigger mechanism 60 attached to the left side of the table 40, a second trigger mechanism 65 with the cutting edge directed in the Y direction is provided on the front side or the back side in FIG. When performing laser processing continuously along the two directions of the direction and the Y direction, efficient processing can be performed.

(Control system)
Subsequently, a control system of the laser processing apparatus LM3 will be described. FIG. 15 is a block diagram showing a control system of the laser processing apparatus LM3. The laser processing apparatus LM1 includes a suction / levitation mechanism drive unit 81 that drives the suction mechanism and the floating mechanism of the table 40, a substrate guidance mechanism drive unit 82 that drives the movable contact portions 51a and 51b of the substrate guidance mechanism 50, and a trigger mechanism 60. A trigger mechanism driving unit 83 for driving the lifting mechanism 61 and the articulated arm 63, a scanning mechanism driving unit 84 for moving the plane mirrors M7 and M8 of the scanning mechanism 22, a laser driving unit 85 for irradiating a laser beam, and a cooling nozzle. When forming a cooling spot that follows the beam spot BS, the cooling nozzle drive unit 86 that sprays the coolant from the coolant nozzle, the camera drive unit 87 that performs imaging by the CCD cameras 55a and 55b, and the optical path switching of the long axis direction switching unit 30 Each drive system of the optical path switching mechanism driving unit 88 that drives the mechanism 31 and the optical path matching mechanism 32 that is linked to the mechanism 31 includes a computer. It is controlled by the configured control unit 80 over data (CPU).

  The control unit 50 is connected to an input unit 91 including an input device such as a keyboard and a mouse, and a display unit 92 including a display screen for performing various displays, and necessary messages are displayed on the display screen and necessary. Instructions and settings can be entered.

(Operation example)
Next, a typical processing operation example by the laser processing apparatus LM3 will be described. Here, the case where the fixed glass substrate G in which the alignment mark was engraved is scribed in the first direction and the second direction orthogonal to each other will be described. For convenience of explanation, the first direction is the x direction of the glass substrate, the second direction is the y direction of the glass substrate, and when the alignment mark is used for positioning, the x direction matches the X direction of the laser scanning optical system. To do.

  When the glass substrate G is placed on the table 40, first, the substrate G is positioned using the substrate guiding mechanism 50. For positioning, the alignment marks on the substrate G are detected by the cameras 55a and 55b, and the amount of displacement is obtained. Subsequently, the movable contact portions 51 a and 51 b are driven to bring the contact members 54 a and 54 b closer to the substrate side surface of the substrate G. At the same time, the floating mechanism is operated to lift the substrate G from the table surface. At this time, the movement of the glass substrate G is restricted by the contacts (four locations) with the contact members 54a and 54b. Subsequently, the movable contact portions 51a and 51b are driven to move (translate and rotate) the substrate G in the horizontal direction and stop at a position where the amount of positional deviation becomes zero. Then, the floating mechanism is stopped and the suction mechanism is operated to fix the substrate G to the table surface. As a result, positioning is completed in a state where the x direction of the substrate G coincides with the X direction of the laser scanning optical system.

  Subsequently, the trigger mechanisms 60 and 65 are driven to create the initial crack TR at the scribe start position of the glass substrate G. Subsequently, in order to perform scanning in the X direction, the long-axis direction switching unit 30 is driven so that the long axis of the beam spot BS is directed in the X direction to select the second optical path. Subsequently, the scanning mechanism unit 22 is driven to adjust the positions of the plane mirrors M7 and M8 so that the beam spot BS comes outside the scribe start position of the substrate G. Subsequently, scribing is performed in the x direction of the glass substrate by moving (scanning) the plane mirror M8 in the X direction while irradiating the laser beam BS. When the scribe in the x direction is further repeated, the movement in the Y direction (laser stop) by the plane mirror M7 and the movement in the X direction (scanning) (laser irradiation) by the plane mirror M8 are alternately performed.

When the scribing process in the x direction of the glass substrate is finished, the long axis direction switching unit 30 is driven so that the long axis of the beam spot BS faces the Y direction to select the first optical path in order to scan in the Y direction. Subsequently, the scanning mechanism unit 22 is driven to adjust the positions of the plane mirrors M7 and M8 so that the beam spot BS comes outside the scribing start position of the substrate G. Subsequently, scribing is performed in the y direction of the glass substrate by moving (scanning) the plane mirror M8 in the Y direction while irradiating the laser beam BS. When the scribing in the y direction is further repeated, the movement in the X direction (laser stop) by the plane mirror M7 and the movement in the Y direction (scanning) (laser irradiation) by the plane mirror M8 are alternately performed.
With the above operation, scribing in the x direction and the y direction is completed on the glass substrate G.

Therefore, in this apparatus, there is no drive mechanism for rotating and moving the table 40, and no drive mechanism having a large driving force is required at all.
Further, the installation space for the apparatus is only an area occupied by the table 40 and an area such as the scanning mechanism 22 arranged around the area, so that the structure is compact.
Further, the scribe in the x direction and the scribe in the y direction can be continuously performed without moving the substrate.

(Modified embodiment)
In the third embodiment, a circular beam (original beam) emitted from one laser light source 10 is shaped into an elliptical beam of parallel light beams by a beam shaping unit 21 using four parabolic mirrors. In place of the laser light source 10 of the LM3, a small-diameter circular beam emitted from two or more laser light sources may be used to form a beam substantially regarded as an elliptical beam spot of a parallel light beam by a simpler method. Good. That is, by illuminating two or more beams side by side, the major axis direction and the minor axis direction of the elliptical beam can be made substantially.

FIG. 19 is a perspective view showing an optical path of an elliptical beam in a modified embodiment of the laser processing apparatus LM3 that irradiates two small-diameter circular beams emitted from two laser light sources 10a and 10b as substantial elliptical beams. . Here, the direction connecting the two circular beams is the substantial major axis direction. When three laser beams are arranged, three circular beams are arranged in series, and the series direction is the major axis. In this case, the mechanism for adjusting the mounting position of the laser light sources 10 a and 10 b substantially functions as the beam shaping unit 21.
For convenience, when a circular beam from the laser light source 10a is illustrated as a white circle and a circular beam from the laser light source 10b is illustrated as a black circle, a beam spot is formed on the substrate along an optical path as shown in FIG.
In this embodiment, the optical system for shaping the elliptical beam of parallel light can be simplified.

  The present invention can be used for a laser processing apparatus in which scribing or ablation processing is performed by laser irradiation.

Claims (20)

A fixed table in which a substrate mounting surface is formed of a porous member, and is provided with an adsorption mechanism for adsorbing the substrate through the porous member and a levitation mechanism for blowing gas to the substrate through the porous member When,
A laser light source;
Laser beam scanning optical system that shapes the laser beam emitted from the laser light source into an elliptical laser beam, guides it to the processed surface of the substrate, and scans along the long axis direction of the elliptical beam spot irradiated on the substrate When,
When positioning or moving a substrate placed on the table, the substrate is guided by a movable contact portion that contacts the side surface of the substrate that has been levitated and moves the substrate side surface in a horizontal direction against the table surface. A laser processing apparatus comprising: a substrate guiding mechanism for performing the operation.   The laser processing apparatus according to claim 1, wherein the substrate guiding mechanism is provided with a plurality of movable contact portions, and the movable contact portions are disposed so as to sandwich the substrate.   The laser processing apparatus according to claim 2, wherein each movable contact portion has a portion that contacts the side surface of the substrate branches and contacts the substrate at two locations.   The laser processing apparatus according to claim 1, wherein the substrate guiding mechanism includes an arm having a joint portion for freely moving the movable contact portion in a horizontal direction on the table surface. The laser beam scanning optical system shapes a laser beam emitted from a laser light source and emits a parallel beam with an elliptical section, or a non-parallel beam with an elliptical section.
An optical path adjustment unit that adjusts the emission direction of the elliptical beam emitted from the beam shaping unit and adjusts and emits the elliptical beam of the parallel light beam when the elliptical beam is a non-parallel light beam,
A scanning axis moving mirror that moves while reflecting the elliptical beam of the parallel light beam emitted from the optical path adjusting unit and scans the elliptical beam spot on the substrate, and moves the scanning axis moving mirror along the long axis direction of the beam spot A scanning mechanism unit comprising a scanning axis guide mechanism,
The laser processing apparatus according to claim 1, wherein the laser light source and the beam shaping unit are installed independently of the scanning mechanism unit so that the beam shaping unit does not move when scanning the beam spot.   The scanning mechanism further includes a feed axis moving mirror that moves in a direction perpendicular to the long axis direction of the beam spot, and a feed axis guide mechanism that moves the feed axis moving mirror along a direction perpendicular to the long axis direction of the beam spot. The laser processing apparatus according to claim 5, wherein the elliptical beam of the parallel light beam emitted from the optical path adjusting unit is reflected in the order of the feed axis moving mirror and the scanning axis moving mirror to form a beam spot on the substrate.   The scanning axis guide mechanism performs a guide for moving the scanning axis moving mirror in a direction perpendicular to the long axis direction of the beam spot, and a scanning axis guide rail for guiding the moving axis moving mirror in the long axis direction of the beam spot. The laser processing apparatus according to claim 6, further comprising a feed shaft guide rail, wherein the scan shaft guide rail is connected to the feed shaft moving mirror and moves integrally. The beam shaping unit includes a beam deformation unit composed of a pair of parabolic mirrors arranged so as to form a confocal point with each other,
The beam deforming unit emits the laser beam to the other parabolic mirror while one parabolic mirror reduces or expands the laser beam in one direction. 6. The laser processing apparatus according to claim 5, wherein the laser beam is emitted as an elliptical laser beam of parallel light beams having a defined axial width. Two beam deformation units are provided, one beam deformation unit for forming a short axis composed of a pair of a first parabolic mirror and a second parabolic mirror arranged so as to form a first confocal point with each other. A beam deforming unit is formed, and the other beam deforming unit is formed with a pair of a third parabolic mirror and a fourth parabolic mirror arranged so as to form a second confocal with each other. Make a unit,
The short-axis forming beam deforming unit emits the second parabolic mirror to the second parabolic mirror while the first parabolic mirror reduces the laser beam emitted from the laser light source in the first direction. The object mirror shapes the incident laser beam into an elliptical laser beam of a parallel beam with a short axis width and emits it toward a beam deforming unit for forming a long axis,
The long axis forming beam deforming unit is configured such that the fourth parabolic mirror expands the laser beam emitted from the second parabolic mirror in a second direction orthogonal to the first direction while performing a fourth beam. The fourth parabolic mirror emits an incident laser beam after shaping the laser beam into an elliptical beam of a parallel light beam having a short axis width and a long axis width determined. The laser processing apparatus as described.   A plurality of pairs of paraboloidal mirrors with different optical constants are prepared, and the beam deformation unit is exchanged as a set for each pair of parabolic mirrors when changing the cross-sectional shape of the elliptical beam of the parallel beam to be emitted. Item 9. A laser processing apparatus according to Item 8. The beam deforming unit has one of the paired parabolic mirrors as a fixed focus parabolic mirror whose mounting position is fixed, and the other parabolic mirror as a movable variable focus parabolic mirror,
9. The laser processing apparatus according to claim 8, wherein when the movable parabolic mirror is moved, the focal point is simultaneously changed to form a confocal point with the fixed parabolic mirror.   The variable-focus parabolic mirror includes a flexible parabolic mirror body that reflects a laser beam, a fixed spindle that supports one end of the parabolic mirror body and is fixed to a pedestal, and a parabolic mirror body. A movable support shaft that supports the other end of the fixed support shaft and that can be translated and rotated in a plane direction orthogonal to the axial direction of the fixed support shaft, a translation drive mechanism that drives the movable support shaft, and a rotation drive mechanism. Item 12. The laser processing apparatus according to Item 11. The optical path adjustment unit of the laser beam scanning optical system further includes a first elliptical beam in which the major axis direction of the elliptical beam emitted from the beam shaping unit is directed to the first direction, and the major axis direction of the elliptical beam is orthogonal to the first direction. A long axis direction switching unit that selectively emits one of the second elliptical beams directed in the second direction;
Based on the first elliptical beam or the second elliptical beam emitted from the major axis direction switching unit, the scanning mechanism unit has a major axis direction orthogonal to the first elliptical beam spot or the first beam spot on the substrate. 7. The laser processing according to claim 6, wherein a second elliptical beam spot is formed, and the beam spot on the substrate is moved along two major axis directions of the first elliptical spot or the second elliptical spot. apparatus.   The long axis direction switching unit includes a first optical path in which an optical element is arranged so that the long axis direction of the elliptical beam emitted from the beam shaping unit faces the first direction, and the long axis direction of the elliptical beam is orthogonal to the first direction. A second optical path in which an optical element is arranged so as to face the second direction, and an optical path switching mechanism that selects the traveling direction of the elliptical beam emitted from the beam shaping unit as the first optical path or the second optical path. The laser processing apparatus according to claim 13.   The laser processing apparatus according to claim 14, wherein the optical path switching mechanism includes a movable mirror that is disposed on the optical path and switches a reflection direction.   The long axis direction switching unit includes an optical path matching mechanism in which the first optical path and the second optical path intersect on the exit side, and an optical path matching mechanism is provided in the intersecting region to direct the directions of the first optical path and the second optical path in the same direction. The laser processing apparatus according to claim 14, which selectively emits either the first elliptical beam that has passed through the first optical path or the second elliptical beam that has passed through the second optical path.   The laser processing apparatus according to claim 16, wherein the optical path matching mechanism includes a movable mirror inserted into and removed from the intersecting region.   The laser processing apparatus according to claim 14, wherein the optical elements arranged in the first optical path and the second optical path are made of a plane mirror group.   The laser processing apparatus according to claim 13, wherein the cutting edge is directed in the major axis direction of the first beam spot and the major axis direction of the second beam spot, and two trigger mechanisms for forming an initial crack in each direction are provided independently. .   14. The laser processing apparatus according to claim 13, wherein the beam shaping unit emits a plurality of small-diameter parallel light beams emitted from a plurality of laser light sources so that the column direction is substantially the long axis direction by arranging them in parallel and in series. .

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