JP2013116488A - Beam machining apparatus and method for machining substrate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a beam machining apparatus that machines a substrate at high speed with high accuracy by continuously irradiated beams and is compactly configured and to provide a method for machining a substrate using the same.SOLUTION: The beam machining apparatus includes: a beam output source 18 for outputting a beam; a beam deflector 20 for reflecting the beam by a reflection surface to be deflected and driven, which deflects the beam in a main scanning direction of the substrate 12; a plurality of first reflectors 22a-22h arranged between the reflection surface of the beam deflector 20 and the substrate 12 in the main scanning direction, which have a reflection plane for reflecting the beam reflected and deflected by the reflection surface; a plurality of second reflectors 24a-24h arranged corresponding to the first reflectors 22a-22h in the main scanning direction, which reflect the beam reflected by the first reflectors 22a-22h and have the reflection plane for guiding the beam in the main scanning direction of the substrate 12; and a substrate moving mechanism 49 for moving the substrate 12 in a sub-scanning direction different from the main scanning direction.

Description

  The present invention relates to a beam processing apparatus that irradiates a substrate with a beam and processes the substrate, and a substrate processing method using the beam processing apparatus.

  Conventionally, laser beam processing apparatuses using laser beams have been widely used in various fields such as substrate cutting, welding, soldering, electronic circuit board drilling, electronic circuit processing, patterning, and thin film peeling processing. Has been used. In particular, in the manufacturing process of thin-film solar cell panels, there is an urgent need to improve the mass productivity and reduce the cost, and in order to realize high quality separation groove scribing with few defects, a laser is required. A beam processing apparatus is used.

  For example, Patent Document 1 discloses a laser that forms a linear separation groove by positioning and fixing a solar cell substrate on a stage and irradiating the solar cell substrate with a laser beam while moving the stage two-dimensionally. A beam processing apparatus is disclosed.

  Further, Patent Document 2 discloses a laser beam processing apparatus that processes a substrate by scanning a laser beam using a galvano mirror with respect to a substrate that is positioned and fixed on a stage.

  Further, in Patent Document 3, the laser beam deflected by the mirror head is reflected by a plurality of distribution mirrors arranged near the drawing area, and then the laser beam reflected by the distribution mirror is arranged outside. A drawing apparatus applied to a laser marker or the like configured to be reflected again by a plurality of peripheral mirrors and guided to a drawing area is disclosed.

JP 2011-156583 A JP 2010-142846 A JP2011-625A

  In this case, in Patent Document 1, since the stage with a large mass to which the solar cell substrate, which is the substrate, is fixed is moved two-dimensionally, it is difficult to move the stage at high speed, and the processing time is shortened. There are limits. In addition, since a long time is required for processing, the temperature of the substrate fluctuates during processing, and the substrate is deformed. Therefore, there is a disadvantage that high-precision processing cannot be performed.

  In Patent Document 2, the substrate is scanned by deflecting the laser beam with a galvanometer mirror, and in order to avoid the distance from the galvanometer mirror to the substrate depending on the scanning position, the focal length of an fθ lens or the like is used. An adjustment mechanism is required. In this case, since the scanning range of the laser beam is restricted by the size of the fθ lens, it is difficult to ensure a wide scanning range. Further, since the laser beam is irradiated obliquely onto the substrate on the end side in the scanning direction and the beam spot shape changes, high-precision processing cannot be performed.

  These problems are particularly serious issues in the manufacturing process of thin-film solar cell panels and the like that require mass productivity for cost reduction and high-definition processing.

  Further, the drawing apparatus of Patent Document 3 introduces a laser beam into a distribution mirror arranged corresponding to each drawing area and performs drawing individually for each drawing area. For example, it is not possible to draw a smooth straight line with high accuracy and little unevenness on the substrate. Further, in Patent Document 3, since the laser beam is deflected two-dimensionally and two-dimensional drawing is performed, if the drawing range is wide, the deflection angle of the laser beam becomes too large. If the deflection angle of the laser beam is large, the beam spot shape on the drawing area may be greatly deformed, or the energy density of the laser beam with respect to the drawing area may be uneven depending on the location, and high-precision drawing may not be guaranteed. .

  The present invention has been made in order to solve the above-mentioned problems, and a beam capable of processing a substrate at high speed and with high accuracy by a continuously irradiated beam and which can be made compact. It is an object of the present invention to provide a processing apparatus and a substrate processing method using the same.

  A beam processing apparatus according to the present invention irradiates a substrate with a beam, and in the beam processing apparatus that processes the substrate, reflects the beam by a beam output source that outputs the beam and a reflection-driven reflection surface, A beam deflector for deflecting a beam in the main scanning direction of the substrate; and a reflection plane arranged in the main scanning direction between the reflecting surface and the substrate and reflecting the beam reflected and deflected by the reflecting surface. A plurality of first reflectors, and arranged in the main scanning direction corresponding to the first reflectors, reflecting the beams reflected by the first reflectors, and the main scanning direction of the substrate A plurality of second reflectors having reflection planes leading to the substrate, and a substrate moving mechanism for moving the substrate in a sub-scanning direction different from the main-scanning direction, each of the first reflectors and each of the second reflectors Characterized in that the optical path length of the beam reaching the substrate from the beam output source is disposed substantially equal position.

  In the beam processing apparatus, a first cylindrical lens having a condensing characteristic in the sub-scanning direction and condensing the beam on the substrate is disposed between the second reflector and the substrate. It is characterized by that.

  In the beam processing apparatus, a first restricting member that restricts a range in the sub-scanning direction of the beam reflected by the second reflector is provided between the second reflector and the first cylindrical lens. It is characterized by being arranged.

  In the beam processing apparatus, a second regulating member that regulates a range in the main scanning direction of the beam reflected by each second reflector is provided between the second reflector and the first cylindrical lens. It is characterized by being arranged.

  In the beam processing apparatus, the reflection surface that has a condensing characteristic in a direction orthogonal to the deflection direction of the beam and is driven to deflect between the reflection surface of the beam deflector and the first reflector. A second cylindrical lens for correcting the tilting of the surface is disposed.

In the beam processing apparatus, an inclination angle α of each first reflector with respect to the main scanning direction, an inclination angle β of each second reflector with respect to the main scanning direction, and the reflection surface of the reflection surface of the beam deflector. The inclination angle γ with respect to the main scanning direction is
β-α ≒ γ
It is set according to the relationship of.

  In the beam processing apparatus, the reflection surface is configured by a first prism.

  In the beam processing apparatus, at least one of the first reflector and the second reflector is constituted by a second prism.

  In the beam processing apparatus, the beam deflector is a rotating polyhedron having a plurality of the reflecting surfaces that are rotationally driven.

  In the beam processing apparatus, the substrate is a solar cell substrate in which a separation groove is processed by the beam.

  A substrate processing method according to the present invention is a substrate processing method in which a substrate is irradiated with a beam, and the substrate is processed, the beam output from a beam output source is reflected by a reflection-driven reflection surface, and the beam is reflected. A step of deflecting the substrate in the main scanning direction and moving the substrate in a sub-scanning direction different from the main scanning direction; and a reflection plane in which the beam reflected by the reflecting surface is arranged in the main scanning direction Sequentially reflecting the plurality of first reflectors, and reflecting the beams reflected by the first reflectors in the main scanning direction corresponding to the first reflectors. Sequentially reflecting the plurality of second reflectors, and irradiating the beam reflected by each of the second reflectors in the main scanning direction of the substrate. Each of the first reflector and the second reflector is disposed at a position where the optical path lengths of the beams from the beam output source to the substrate are substantially equal. Features.

  In the substrate processing method, the beam reflected by each of the second reflectors is condensed only in the sub-scanning direction and irradiated onto the substrate.

  In the substrate processing method, the range of the beam in the sub-scanning direction is regulated to focus the beam only in the sub-scanning direction.

  In the substrate processing method, the range of the beam in the main scanning direction is regulated to focus the beam only in the sub-scanning direction.

  In the substrate processing method, the beam reflected and deflected by the reflecting surface is condensed in a direction orthogonal to the deflection direction of the beam, and surface tilt correction of the reflecting surface is performed.

  In the substrate processing method, the substrate is a solar cell substrate in which a separation groove is processed by the beam.

  In the beam processing apparatus and the substrate processing method using the same according to the present invention, the substrate is moved in the sub-scanning direction, while the beam output from the beam output source is reflected and deflected, and the plurality of first reflectors and second reflections are generated. The substrate can be processed two-dimensionally by main-scanning the substrate through the body.

  In this case, the deflected beam is continuously reflected in the main scanning direction by the reflection planes of the plurality of first reflectors arranged in the main scanning direction, and then the plurality of second reflections arranged in the main scanning direction. The light is continuously reflected again in the main scanning direction by the reflection plane of the body, and then irradiated in the main scanning direction of the substrate moving in the sub-scanning direction. Each of the first reflectors and each of the second reflectors is disposed at a position where the optical path lengths of the beams guided to the substrate are approximately equal to each other. It can be processed at high speed.

  Further, since the beam is reflected by the first reflector disposed between the beam polarizer and the substrate, guided to the second reflector, and then guided to the substrate, the apparatus is configured compactly. be able to.

  In the present invention, the beam reflected by the second reflector is condensed only in the sub-scanning direction and irradiated onto the substrate, thereby obtaining a very good processing state without unevenness along the main scanning direction. it can.

  In addition, by restricting the range of the beam in the sub-scanning direction and condensing the beam only in the sub-scanning direction and irradiating the substrate, energy concentration at the center of the beam spot due to condensing in the sub-scanning direction is suppressed, It is possible to obtain a very good processing state without further unevenness along the main scanning direction.

  Further, by restricting the range of the main scanning direction of the beam and condensing the beam only in the sub-scanning direction, overlapping of the beams in the main scanning direction by the respective first reflectors on the substrate is eliminated, and in the main scanning direction. A very good processing state without further unevenness can be obtained.

  In addition, by converging the beam reflected and deflected by the reflecting surface in a direction orthogonal to the deflection direction, the tilting of the reflecting surface is corrected and fluctuations in the sub-scanning direction of the beam are suppressed. A machining state with extremely good linearity with respect to the direction can be obtained.

  Furthermore, according to the present invention, the solar cell substrate has no irregularities and has extremely good linearity, and a high-precision separation groove continuous in the main scanning direction can be processed at high speed.

It is a section lineblock diagram of a beam processing device of an embodiment concerning the present invention. It is a plane block diagram of the beam processing apparatus shown in FIG. It is the III-III line expanded sectional view of FIG. It is a partial expansion explanatory view of the beam processing apparatus shown in FIG. 5A is an explanatory plan view of a mask member and a light shielding member disposed in the beam processing apparatus shown in FIG. 1, and FIG. 5B is an explanatory side sectional view of the mask member and the light shielding member. It is a control block diagram of the beam processing apparatus shown in FIG. It is a process flowchart of the beam processing apparatus shown in FIG. FIG. 8A is an explanatory view of a separation groove of a comparative example, and FIG. 8B is an explanatory view of the separation groove processed by the beam processing apparatus of this embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

[Configuration of beam processing equipment]
FIG. 1 is a cross-sectional configuration diagram of a beam processing apparatus 10 according to an embodiment of the present invention. FIG. 2 is a plan view of the beam processing apparatus 10 shown in FIG. 3 is an enlarged sectional view taken along line III-III in FIG. In FIG. 3, for convenience of explanation, a part of prisms 24a to 24h described later is shown.

  The beam processing apparatus 10, for example, performs scribing on a substrate 12 (a TCO (Transparent Conducing Oxide) film deposited on a glass substrate), which is a substrate for a thin film solar cell, using a laser beam LB (FIG. 3). , An apparatus for forming a separation groove 52 (FIG. 2) from which the TCO film has been removed in a straight line, and is configured by housing each component in the casing 14. The beam processing apparatus 10 has two air bearings 16a and 16b that extend in the main scanning direction (arrow X direction) and support the substrate 12 in a floating state (non-contact state). The substrate 12 is moved in the sub-scanning direction (arrow Y direction) orthogonal to the main scanning direction by a substrate moving mechanism 49 described later while being floated by the air bearings 16a and 16b.

  The beam processing apparatus 10 includes a laser 18 (beam output source) that outputs a laser beam LB, a polygon-shaped rotating polyhedron 20 (beam deflector) that deflects the laser beam LB in the main scanning direction of the substrate 12, and a laser beam LB. Reflection mirrors 22a to 22h (first reflector) for reflecting the laser beam, a plurality of prisms 24a to 24h (second reflector and second prism) for reflecting the laser beam LB, and a direction orthogonal to the deflection direction of the laser beam LB. And a plurality of cylindrical lenses 26a to 26h (first cylindrical lenses) having a condensing characteristic only in the sub-scanning direction.

  Between the laser 18 and the rotating polyhedron 20, a prism 28 (FIG. 3) is arranged that bends the optical path of the laser beam LB output from the laser 18 by 90 ° in the upward direction and guides it to the rotating polyhedron 20.

  In the rotating polyhedron 20, a hexagonal columnar holder 34 is connected to the rotating shaft 32 of the rotating polyhedron driving motor 30. On the side surface of the holder 34, six prisms 36 (first prisms) that are driven to rotate (deflection) and form a plurality of reflecting surfaces that reflect the laser beam LB are disposed. The rotating shaft 32 is orthogonal to the main scanning direction. Each prism 36 of the rotating polyhedron 20 has two reflecting surfaces 38 a and 38 b, the laser beam LB introduced through the prism 28 is reflected by the two reflecting surfaces 38 a and 38 b, and the laser beam LB is reflected on the substrate 12. Deflection in the main scanning direction. The optical axis of the laser beam LB emitted from the rotating polyhedron 20 is shifted by Δy1 in the direction perpendicular to the main scanning direction with respect to the optical axis of the laser beam LB incident on the rotating polyhedron 20.

  Between the rotating polyhedron 20 and each of the reflecting mirrors 22a to 22h, the laser beam LB reflected from the rotating polyhedron 20 toward each of the reflecting mirrors 22a to 22h is arranged in an arc shape. Cylindrical lenses 40a to 40h (second cylindrical lenses) are disposed. The cylindrical lenses 40a to 40h are optical elements for surface tilt correction having a condensing characteristic that condenses the laser beam LB only in the sub-scanning direction orthogonal to the deflection direction. The cylindrical lenses 40a to 40h correct the shake of the optical axis of the laser beam LB caused by the tilting of the reflecting surfaces 38a and 38b of the prism 36 that occurs when the rotating polyhedron 20 rotates in the direction of the arrow θ. Note that the cylindrical lenses 40a to 40h may be omitted when there is no need to correct the optical axis of the laser beam LB due to surface tilt.

  The reflecting mirrors 22 a to 22 h are arranged in the main scanning direction between the rotating polyhedron 20 and the substrate 12. Each of the reflection mirrors 22a to 22h has reflection planes 19a to 19h that reflect the laser beam LB reflected and deflected by the reflection surfaces 38a and 38b of the rotating polyhedron 20 toward the corresponding prisms 24a to 24h.

  The prisms 24a to 24h have two reflection planes 21a to 21h and 23a to 23h. The prisms 24a to 24h are arranged in the main scanning direction corresponding to the reflecting mirrors 22a to 22h, and reflect the laser beams LB reflected by the reflecting planes 19a to 19h of the reflecting mirrors 22a to 22h to reflect the main beam of the substrate 12. Guide in the scanning direction.

  FIG. 4 is a partially enlarged explanatory view of the beam processing apparatus 10 shown in FIG. In addition, illustration is abbreviate | omitted about each left side component in FIG.

In the reflecting mirrors 22a to 22h and the prisms 24a to 24h, the laser beam LB output from the laser 18 is reflected by the prism 36 of the rotating polyhedron 20, and all the optical path lengths from the laser 18 to the substrate 12 are substantially equal. Arranged in position. For example, the optical path length from the reflecting surface 38b of the rotating polyhedron 20 to the center in the arrow X direction of the reflecting planes 19a to 19h of the reflecting mirror 22e is a1, and the prism 24e from the center in the arrow X direction of the reflecting planes 19a to 19h of the reflecting mirror 22e. An optical path length from the center of the reflection planes 21a to 21h to the center in the arrow X direction is b1, and an optical path length from the center of the reflection planes 23a to 23h of the prism 24e to the substrate 12 incident on the substrate 12 is c1. Similarly, the optical path length from the rotating polyhedron 20 to the center in the arrow X direction of the reflecting mirror 22f is a2, the optical path length from the center of the reflecting mirror 22e to the center in the arrow X direction of the prism 24e is b2, and the arrow X direction of the prism 24e is Let c2 be the optical path length from the center to the substrate 12 incident on the substrate 12 perpendicularly. In this case, the arrangement relationship between the set of the reflection mirror 22e and the prism 24e and the set of the reflection mirror 22f and the prism 24f is
a1 + b1 + c1≈a2 + b2 + c2 (1)
Set according to the relationship. Similarly, the arrangement relationship of the sets of the other reflecting mirrors 22a to 22h and the prisms 24a to 24h is set according to the equation (1).

As shown in FIG. 4, the inclination angle of the reflection mirrors 22a to 22h with respect to the main scanning direction is α, and the inclination angle of the prisms 24a to 24h with respect to the main scanning direction is β. The tilt angle α and the tilt angle β are set so that the laser beam LB incident on the center of the reflecting mirrors 22a to 22h in the main scanning direction is incident on the substrate 12 substantially perpendicularly. That is, assuming that the angle of inclination of the reflecting surfaces 38a, 38b of the rotating polyhedron 20 with respect to the main scanning direction is γ,
β-α ≒ γ (2)
Set according to the relationship. The inclination angles α, β, and γ are absolute values.

Further, the length m of each reflection mirror 22a to 22h is set to a length corresponding to each scanning range La to Lh of the laser beam LB guided to the substrate 12 by each reflection mirror 22a to 22h. That is, the length m of each reflection mirror 22a-22h is the scanning range L (La-Lh), the optical path length a from the rotary polyhedron 20 to the center of each reflection mirror 22a-22h, and each reflection mirror from the rotation polyhedron 20 to each reflection mirror. Using the optical path length d from the center of 22a to 22h to the substrate 12, and the inclination angle α of the reflection mirrors 22a to 22h,
m≈a / d × L / cosα (3)
Set according to the relationship.

  The optical path lengths of the laser beams LB reflected by the reflecting mirrors 22a to 22h are the laser beam LB incident on one end of the reflecting mirrors 22a to 22h extending in the main scanning direction and the laser beam LB incident on the other end. And slightly different. This difference in optical path length is suppressed by dividing the entire scanning range of the laser beam LB in the main scanning direction by using the plurality of reflection mirrors 22a to 22h, and the reduction in processing accuracy due to fluctuations in the optical path length is suppressed. it can. The number of divisions of the scanning range in the main scanning direction of the laser beam LB using the reflecting mirrors 22a to 22h (in this embodiment, eight divisions) depends on the required processing accuracy and the processing width of the substrate in the main scanning direction. Accordingly, it may be other than eight divisions.

  The lengths of the prisms 24a to 24h may be long enough to reliably reflect the laser beam LB reflected by the reflection mirrors 22a to 22h.

  The cylindrical lenses 26 a to 26 h have a condensing characteristic in the sub-scanning direction orthogonal to the deflection direction of the laser beam LB, and condense the laser beam LB on the substrate 12. The cylindrical lenses 26a to 26h are set to a length capable of guiding the laser beam LB to the scanning ranges La to Lh on the substrate 12, and are arranged in the main scanning direction. In this case, the cost required for manufacturing can be reduced by setting the cylindrical lenses 26a to 26h to the same length. Further, the cylindrical lenses 26a to 26h can be formed at low cost by using high-precision cylindrical lenses 26a to 26h having no irregularities whose surfaces are fire-polished.

  5A is an explanatory plan view of the mask members 25a to 25h and 27a to 27h and the light shielding members 29a to 29i arranged in the beam processing apparatus 10 shown in FIG. 1, and FIG. 5B is a mask member 25a to 25h and 27a to 27h. FIG. 4 is a side cross-sectional explanatory view of light shielding members 29a to 29i.

  The mask members 25a to 25h and 27a to 27h (first restriction members) are disposed between the prisms 24a to 24h and the cylindrical lenses 26a to 26h. The mask members 25a to 25h and 27a to 27h are installed inside a predetermined distance (for example, twice the focal length of the cylindrical lenses 26a to 26h) from the incident surfaces of the cylindrical lenses 26a to 26h, and are shown in FIGS. 5A and 5B. As shown, it is arranged in parallel to the main scanning direction (arrow X direction). The mask members 25 a to 25 h and 27 a to 27 h regulate the range in the sub-scanning direction of the laser beam LB reflected by the prisms 24 a to 24 h and guided to the substrate 12. A slit 31 for guiding the laser beam LB to the cylindrical lenses 26a to 26h is formed between the mask members 25a to 25h and 27a to 27h. As shown by the arrows in FIG. 5A, the positions of the mask members 25a to 25h and 27a to 27h can be individually adjusted with respect to the sub-scanning direction (arrow Y direction). The mask members 25a to 25h and 27a to 27h remove the predetermined range of the beam spot 33 of the laser beam LB incident on the cylindrical lenses 26a to 26h by adjusting the width of the slit 31 in the sub-scanning direction. The mask members 25a to 25h and 27a to 27h scan the laser beam LB irradiated to the substrate 12 in a straight line along the main scanning direction. Note that any one of the mask members 25a to 25h and 27a to 27h disposed between the prisms 24a to 24h and the cylindrical lenses 26a to 26h may be used.

  Light shielding members 29a to 29i (second regulating members) extending toward the prisms 24a to 24h, which are incident directions of the laser beam LB, are disposed at both ends of the mask members 25a to 25h and 27a to 27h. The light shielding members 29a to 29i regulate the range in the main scanning direction of the laser beam LB reflected by the prisms 24a to 24h and guided to the substrate 12 so that the laser beam LB is not superimposed on the substrate 12 in the main scanning direction. A portion of the laser beam LB incident on the cylindrical lenses 26a to 26h in the main scanning direction is shielded from light.

  FIG. 6 is a control block diagram of the beam processing apparatus 10 shown in FIG.

  The beam processing apparatus 10 includes a processing parameter setting unit 42 that sets processing parameters for performing desired processing on the substrate 12, and a control unit 44 that controls the beam processing apparatus 10 based on the set processing parameters. Is provided. The control unit 44 includes a laser drive unit 46 that drives the laser 18, a rotary polyhedron drive motor 30 that rotates the rotary polyhedron 20, and an air bearing drive that drives air bearings 16a and 16b that support the substrate 12 in a floating state by air pressure. The unit 48 and the substrate moving unit 47 for holding the substrate 12 by the substrate holding units 45a and 45b and moving the substrate 12 in the sub-scanning direction are controlled. The air bearings 16a and 16b, the substrate gripping portions 45a and 45b, the substrate moving portion 47, and the air bearing driving portion 48 constitute a substrate moving mechanism 49 that moves the substrate 12 in the sub-scanning direction. The laser beam LB output from the laser 18 is deflected by the rotating polyhedron 20 and irradiated onto the substrate 12 via the optical system 50. The optical system 50 includes cylindrical lenses 40a to 40h, reflection mirrors 22a to 22h, prisms 24a to 24h, and cylindrical lenses 26a to 26h.

[Operation of beam processing equipment]
Next, the operation of the beam processing apparatus 10 will be described. FIG. 7 is a process flowchart of the beam processing apparatus 10.

  First, the operator uses the processing parameter setting unit 42 to set various processing parameters for processing the substrate 12 (step S1). When the substrate 12 is a thin film solar cell substrate, the processing parameter setting unit 42 scribes a TCO film deposited on the glass substrate to form a plurality of linear separation grooves 52 (FIG. 2). The parameter is set. Here, the separation groove is a groove for constituting a large number of solar cells that are modularized by peeling the TCO film linearly. Processing parameters include the output energy of the laser beam LB, the on / off frequency of the laser beam LB when the laser 18 is a pulse laser, the rotational speed of the rotating polyhedron 20, and the moving speed of the substrate 12 in the sub-scanning direction by the substrate moving unit 47. Etc. are set. For example, the control unit 44 performs on / off control of the laser 18 at 10 kHz for each prism 36 of the rotating polyhedron 20, and performs main scanning of the substrate 12 at a width of 1000 mm and 0.1 second for each pulse and is spaced in the sub-scanning direction. A 1 mm separation groove 52 is formed. In this case, in the beam processing apparatus 10 of the present embodiment, the separation groove 52 can be processed by scribing the TCO film of the substrate 12 at a speed of 10 m / s.

  After the machining parameters are set, the control unit 44 controls the air bearing drive unit 48 to drive the air bearings 16a and 16b (step S2). By driving the air bearings 16a and 16b, the substrate 12 is supported in a floating state (non-contact state) by the air bearings 16a and 16b. The substrate 12 is a solar cell substrate in which a TCO film is formed on the lower surface of the glass plate. When the TCO film is scribed through the glass plate, the substrate 12 is supported without the air bearings 16a and 16b being in contact with the TCO film. can do.

  The control unit 44 controls the rotary polyhedron drive motor 30. The rotary polyhedron drive motor 30 drives the rotary polyhedron 20 to rotate in the direction of the arrow θ (FIGS. 3 and 4) (step S3).

  Next, the control unit 44 controls the substrate moving unit 47. The substrate moving unit 47 holds the side portions 12a and 12b of the upper surface (the surface on which no film is formed) of the substrate 12 with the substrate holding portions 45a and 45b, and moves the substrate 12 in the sub-scanning direction (step S4).

  The control unit 44 controls the laser driving unit 46 in a state where the rotating polyhedron 20 is rotated and the substrate 12 is moved in the sub-scanning direction. The laser driving unit 46 drives the laser 18 (Step S5), and the laser beam LB output from the laser 18 is irradiated in the main scanning direction onto the substrate 12 moving in the sub-scanning direction by the substrate moving unit 47. As a result, a large number of separation grooves 52 having no irregularities and extremely good linearity are two-dimensionally processed in the TCO film formed on the substrate 12 (step S6).

  Next, based on FIGS. 3-5, the process of the separation groove | channel 52 and the detail of the effect are demonstrated.

  In FIG. 3, the laser beam LB output from the laser 18 is reflected by the prism 28, and after the optical path is bent 90 ° upward, it enters the reflecting surface 38 a of the prism 36 constituting the rotating polyhedron 20. The laser beam LB reflected by the reflecting surface 38a is reflected by the reflecting surface 38b of the prism 36. As a result, the optical axis of the laser beam LB is translated by Δy1 in the sub-scanning direction, and is emitted from the rotating polyhedron 20 without interfering with the prism 28.

  Here, since the prism 36 of the rotating polyhedron 20 totally reflects the incident laser beam LB by the reflecting surfaces 38a and 38b, the reflecting film of the prism 36 is damaged by the light energy of the laser beam LB. The laser beam LB can be reflected. Thereby, the lifetime of the rotating polyhedron 20 can be extended. The prism 36 deflects the direction of the laser beam LB by 180 °. Therefore, even if the inclination angles of the reflecting surfaces 38a and 38b vary due to the vibration of the rotating shaft 32 of the rotating polyhedron 20, the emission direction of the laser beam LB emitted from the rotating polyhedron 20 does not change, and the optical axis is changed. It only moves in the sub-scanning direction.

  The laser beams LB reflected by the respective prisms 36 sequentially enter the cylindrical lenses 40a to 40h arranged in the deflection direction of the laser beam LB by the rotating polyhedron 20. The cylindrical lenses 40a to 40h have a condensing characteristic only in a direction orthogonal to the deflection direction of the laser beam LB. In this case, when the surface tilt of the prism 36 occurs due to the vibration of the rotating shaft 32 of the rotating polyhedron 20, the laser beam LB emitted from the rotating polyhedron 20 shifts in a direction orthogonal to the main scanning direction. Is corrected by the condensing action of the cylindrical lenses 40a to 40h in the sub-scanning direction.

  The laser beam LB whose surface tilt of the rotating polyhedron 20 is corrected by the cylindrical lenses 40a to 40h is incident on the reflection planes 19a to 19h, which are reflection planes of the reflection mirrors 22a to 22h, and is sequentially reflected by the reflection mirrors 22a to 22h. Are guided to the corresponding prisms 24a to 24h. Next, the laser beams LB reflected by the reflecting planes 21a to 21h and 23a to 23h, which are the reflecting planes of the prisms 24a to 24h, were formed between the mask members 25a to 25h, 27a to 27h and the light shielding members 29a to 29i. The light is guided to the cylindrical lenses 26a to 26h through the slit 31.

  In this case, the laser beam LB is reflected by being translated by Δy2 (FIG. 3) in the direction orthogonal to the main scanning direction by the reflecting planes 21a to 21h and 23a to 23h of the prisms 24a to 24h. The light is guided to the cylindrical lenses 26a to 26h without interfering with the reflection mirrors 22a to 22h arranged between the 24a to 24h and the cylindrical lenses 26a to 26h. Further, the prisms 24a to 24h, like the prism 36 of the rotating polyhedron 20, totally reflect the incident laser beam LB, so that the reflecting films of the prisms 24a to 24h are not damaged by the light energy of the laser beam LB. The lifetime of the prisms 24a to 24h can be extended.

  The laser beam LB is condensed in the sub-scanning direction by the cylindrical lenses 26a to 26h and irradiated onto the substrate 12.

  The laser beam LB focused on the substrate 12 is deflected by the rotating polyhedron 20 that rotates in the direction of the arrow θ, so that the substrate 12 is main-scanned, and linear separation grooves 52 are continuously formed on the substrate 12. . On the other hand, the substrate 12 is supported in a floating state by the air bearings 16 a and 16 b and is moved in the sub-scanning direction by the substrate moving unit 47. Accordingly, a large number of separation grooves 52 are formed in the substrate 12 at predetermined intervals in the sub-scanning direction.

  As shown in FIG. 4, the reflection direction of the laser beam LB reflected and deflected by the prism 36 of the rotary polyhedron 20 changes with time by the prism 36 that is driven to rotate, and therefore spreads in a sector shape as a whole, and the reflection mirrors 22a to 22b. 22h and the prisms 24a to 24h are led to the substrate 12. In this case, by arranging the reflection mirrors 22a to 22h and the prisms 24a to 24h corresponding to the scanning ranges La to Lh, the laser beam LB guided onto the substrate 12 does not overlap in the main scanning direction, and the substrate 12, the separation grooves 52 can be formed efficiently and continuously.

  For example, it is assumed that the beam processing apparatus 10 is configured to directly reflect the laser beam LB by the prisms 24a to 24h and guide it to the substrate 12 without passing through the reflection mirrors 22a to 22h. Under this assumption, in order to prevent the laser beams LB reflected by the prisms 24a to 24h from overlapping the main scanning direction on the substrate 12, the prisms 24a to 24h are separated by a predetermined distance in the main scanning direction. Need to be placed. However, if the prisms 24a to 24h are arranged apart from each other, a dead time that does not irradiate the substrate 12 occurs when the laser beam LB moves between the prisms 24a to 24h. On the other hand, the substrate 12 continuously moves in the sub-scanning direction. Therefore, when the beam processing apparatus 10 is configured without the reflection mirrors 22a to 22h, the separation groove 52 is formed discontinuously because the substrate 12 moves in the sub-scanning direction during the dead time of the laser beam LB. End up.

  On the other hand, in the beam processing apparatus 10 according to the present embodiment, by providing the reflecting mirrors 22a to 22h in addition to the prisms 24a to 24h, the dead time during which the laser beam LB is not irradiated onto the substrate 12 can be shortened as much as possible. Can do. As a result, the separation grooves 52 that are not divided in the main scanning direction can be continuously formed in the substrate 12.

  Furthermore, in the beam processing apparatus 10 of the present embodiment, the inclination angles α of the reflection mirrors 22a to 22h are set differently with respect to the prisms 24a to 24h according to the relationship of the above-described equation (2). Thereby, the dead time when the laser beam LB moves between the adjacent prisms 24a to 24h can be extremely shortened. As a result, a linear separation groove 52 that is continuous in the main scanning direction can be formed on the substrate 12.

  Further, the laser beam LB passes through the slit 31 between the mask members 25a to 25h and 27a to 27h, so that a predetermined direction in a direction orthogonal to the main scanning direction of the beam spot 33 of the laser beam LB is obtained as shown in FIG. 5A. The range is removed and the light enters the cylindrical lenses 26a to 26h. Therefore, the laser beam LB condensed in the sub-scanning direction by the cylindrical lenses 26a to 26h is partially removed, so that concentration of energy density near the center of the beam spot 33 is suppressed. As a result, the laser beam LB having a substantially uniform energy density is guided to the substrate 12, and the separation groove 52 without unevenness is formed along the main scanning direction.

  Moreover, as shown to FIG. 5B, the light shielding members 29a-29i are arrange | positioned between the adjacent mask members 25a-25h and 27a-27h. The scanning ranges La to Lh of the laser beam LB on the substrate 12 by the reflecting mirrors 22a to 22h are blocked by the light shielding members 29a to 29i so that a part of the laser beam LB is shielded from light corresponding to the scanning ranges La to Lh. The scanning range in the main scanning direction is restricted. As a result, the laser beam LB is guided to the substrate 12 in a state where the scanning ranges La to Lh do not overlap in the main scanning direction, and a very good processing state without further unevenness along the main scanning direction can be obtained.

  Further, the reflecting mirrors 22a to 22h and the prisms 24a to 24h are configured by reflecting planes 19a to 19h, 21a to 21h, and 23a to 23h that reflect the laser beam LB. For this reason, the shape of the beam spot 33 (FIG. 5A) does not vary depending on the scanning position in the main scanning direction, and the laser beam LB is guided to the cylindrical lenses 26a to 26h in a fixed shape.

  From the above, the substrate 12 is irradiated with the laser beam LB having a long shape in the main scanning direction without causing uneven energy density depending on the main scanning position. In addition to not being uneven, the linear separation is very good in the main scanning direction, and a continuous separation groove 52 is formed in the substrate 12.

  FIG. 8A is an explanatory view of the separation groove 54 of the comparative example, and FIG. 8B is an explanatory view of the separation groove 52 processed by the beam processing apparatus 10 of this embodiment.

  In the comparative example of FIG. 8A, the separation groove 54 is formed on the substrate 12 with the mask members 25 a to 25 h and 27 a to 27 h and the cylindrical lenses 26 a to 26 h removed from the beam processing apparatus 10. In this case, since the beam spot 56 (shown by hatching) of the laser beam LB irradiated on the substrate 12 is not shaped at all in the sub-scanning direction, the substrate 12 is irradiated as a substantially circular beam spot 56. . As a result, irregularities corresponding to the shape of the beam spot 56 are formed on the walls 58 a and 58 b in the arrow Y direction of the separation groove 54. The unevenness can be reduced by controlling the distance between the beam spots 56 in the direction of the arrow X to be close. However, in order to make the interval between the beam spots 56 closer, the frequency of the laser beam LB must be set higher or the scanning speed of the laser beam LB in the main scanning direction must be set lower. When the scanning speed is slowed down, the processing time of the separation groove 54 becomes long.

  On the other hand, in the beam processing apparatus 10 of the present embodiment, as shown in FIG. 8B, straight groove portions 52 having no irregularities are formed in the wall portions 62a and 62b in the arrow Y direction. That is, in the beam processing apparatus 10, the laser beam LB having a uniform energy density is irradiated onto the substrate 12, and the laser beam LB is condensed in the arrow Y direction by the cylindrical lenses 26 a to 26 h, thereby forming a substantially rectangular shape. A beam spot 60 (indicated by hatching) is formed on the substrate 12. Therefore, by scanning the beam spot 60 in the direction of the arrow X, the separation groove 52 having extremely smooth wall portions 62a and 62b without unevenness is formed on the substrate 12. In addition, since the separation groove 52 without unevenness can be formed without reducing the scanning speed of the laser beam LB, the processing speed can be increased dramatically.

  Furthermore, the beam processing apparatus 10 uses the rotating polyhedron 20 to deflect the laser beam LB in the main scanning direction. The rotating polyhedron 20 can keep the scanning speed of the laser beam LB on the substrate 12 constant because the rotational speed of the prism 36 that reflects the laser beam LB is constant. Therefore, the substrate 12 is irradiated with the laser beam LB having the same energy density that does not depend on the irradiation position of the laser beam LB, and the separation groove 52 can be formed with high accuracy.

  As described above, in the beam processing apparatus 10 according to the present embodiment, the laser beam LB is reflected by the rotating polyhedron 20 rotating at a constant speed, and the laser beam LB is continuously irradiated in the main scanning direction of the substrate 12. By moving the substrate 12 in the sub-scanning direction using the moving portion 47, a large number of separation grooves 52 that are extremely linear with respect to the substrate 12 and have no irregularities can be formed at high speed and with high accuracy. Therefore, when the substrate 12 which is a solar cell substrate is processed using the beam processing apparatus 10, the TCO film is processed to form a separation groove having a constant width without unevenness with high accuracy and high speed. it can. The solar cell substrate manufactured in this manner can be expected to greatly improve the power generation efficiency because the occurrence of leakage current of the TCO film and the metal electrode film is greatly suppressed.

  Further, since the laser beam LB output from the laser 18 is configured to be reflected by the reflecting mirrors 22a to 22h and the prisms 24a to 24h and irradiated onto the substrate 12, the beam processing apparatus 10 can be easily downsized. Can be achieved.

  The present invention is not limited to the above-described embodiment, and can be modified without departing from the gist of the present invention.

  In the present embodiment, the reflection mirrors 22a to 22h may be configured by prisms, similarly to the prism 36 and the prisms 24a to 24h of the rotating polyhedron 20. Moreover, while reflecting mirror 22a-22h is comprised with a prism, you may comprise prisms 24a-24h as a reflecting mirror.

  If the prisms 36 and 24a to 24h of the rotating polyhedron 20 have sufficient durability against the optical energy of the laser beam LB and can realize an arrangement relationship that does not interfere with the optical path of the laser beam LB, the prisms 36 and 24a to 24h are replaced with prisms. A reflection mirror may be used.

  In the rotating polyhedron 20, six prisms 36 constituting a reflecting surface are arranged in a hexagonal columnar holder 34, but the number of reflecting surfaces is not limited to this, and the substrate 12 is not limited to this. The separation groove 52 to be formed can be appropriately selected according to the length in the main scanning direction. For example, if the length of the separation groove 52 is short, the time interval until the next separation groove 52 is formed in the sub-scanning direction is shortened. Therefore, the rotating polyhedron 20 having the number of reflecting surfaces corresponding to the time interval is used. It is desirable to do.

  The cylindrical lenses 26a to 26h use a plurality of lenses having the same length. However, in order to avoid the influence of reflection at the portions where the cylindrical lenses 26a to 26h are connected to each other, one cylindrical lens is used. You may comprise.

  The cylindrical lenses 40a to 40h for correcting the surface tilt of the laser beam LB are arranged between the rotary polyhedron 20 and the reflection mirrors 22a to 22h. However, the prisms 24a to 24h and the mask members 25a to 25h are provided. You may arrange | position between 27a-27h.

  The rotating polyhedron 20 is effective in that the laser beam LB can be deflected continuously and at a constant speed. However, instead of the rotating polyhedron 20, a beam deflector of another form using a galvanometer mirror or a resonant mirror may be used.

  As the moving mechanism for moving the substrate 12 in the sub-scanning direction, the substrate 12 is moved in a floating state by the air bearings 16a and 16b. Instead of this mechanism, the substrate 12 is supported by a rotating roller and moved. It is possible to adopt various moving configurations according to the substrate that is the object to be processed, such as a mechanism that moves the entire substrate 12 by a stage and a mechanism that moves the entire stage 12.

  Although the substrate 12 is moved at a constant moving speed in the sub-scanning direction orthogonal to the main scanning direction, the main scanning direction and the sub-scanning direction do not necessarily have to be orthogonal. For example, in the case of the beam processing apparatus 10, the separation groove 52 is formed by scanning the substrate 12 moving in the sub-scanning direction (arrow Y direction) with the laser beam LB in the main scanning direction (arrow X direction). ing. In this case, a separation groove 52 that is inclined with respect to the main scanning direction is formed on the substrate 12. In order to avoid the inclination of the separation groove 52, the main scanning direction of the laser beam LB may be set to be shifted from the direction orthogonal to the sub-scanning direction in consideration of the moving speed of the substrate 12. In addition, a curved separation groove 52 can be formed on the substrate 12 by controlling the moving speed in the sub-scanning direction. Further, the substrate 12 not only moves linearly, but, for example, the substrate 12 is placed on a rotary table and the substrate 12 is irradiated with the laser beam LB in a state where the rotary table is rotated in the sub-scanning direction. It is also possible to adopt a configuration for processing.

  In the above description, the thin film solar cell substrate has been described as an example of the substrate 12, but the beam processing apparatus 10 of the present embodiment can be applied to various other fields. For example, it can be applied to thin film peeling using a laser beam, glass cutting machine, line welding machine, processing and patterning of an electronic circuit board, improvement of surface quality of products, and the like. Further, as the substrate, a touch panel substrate, a liquid crystal substrate, a diffraction grating substrate, or the like can be processed. In the thin film peeling process, a pulse laser that can break the critical point for ablation or peeling of the thin film while avoiding damage to the substrate is suitable. For welding and sealing using a laser, a CW laser that continuously irradiates the laser beam LB is suitable.

  In the beam processing apparatus 10 of the present embodiment, the beam spot 60 (FIG. 8B) formed on the substrate 12 has little overlap in the main scanning direction, and the beam spot 60 formed by one pulse of the laser beam LB is set in the main scanning direction. Can be formed long. In this case, the influence of heat on the substrate 12 can be reduced. Therefore, for example, a substrate having a pattern material (applying substrate) and a substrate to which a pattern is to be applied (receiving substrate) are arranged so as to overlap, and the applying material is irradiated with a laser beam LB to peel off the pattern material, The pattern can be transferred. Specifically, by using an electronic circuit board in which the pattern material of the application board is made of copper foil and an electronic circuit element is mounted on the receiving board, the terminals of the circuits and the mounting bodies can be connected with circuit lines. it can. The connection position and shape can be freely controlled using a light shielding member by adjusting the irradiation timing of the laser beam LB irradiating the application substrate and the moving speed of the application substrate in the sub-scanning direction. Note that by appropriately selecting the shape of the light shielding member, a part of the circuit line can be disconnected or a hole can be formed at a desired position on the application substrate.

  Further, in the beam processing apparatus 10 of the present embodiment, the substrate 12 is processed using the single laser 18, but the laser beam LB output from the laser 18 is divided into a plurality of parts, or a plurality of lasers are used. 18 may be used to process the substrate 12. In this case, it is conceivable to irradiate a plurality of laser beams LB on the processing site in the same main scanning direction or to irradiate a plurality of laser beams LB in parallel with the sub-scanning direction of the substrate 12. For example, when the laser beam LB is irradiated on the same main scanning direction processing site, a crack is formed in the substrate 12 having a thin film using an ultraviolet laser, and the substrate 12 using a green laser having an effect different from that of the ultraviolet laser. The thin film can be easily evaporated. Thereby, the efficiency of the cutting of the glass substrate and the multilayer film processing can be improved. Further, when the laser beams LB are arranged in parallel in the sub-scanning direction of the substrate 12 and simultaneously irradiated, the substrate 12 is processed using one or more fringes by generating interference fringes on the substrate 12 with the cylindrical lenses 26a to 26h. can do. Thereby, the processing of the diffraction grating substrate and the processing of fine lines can be performed efficiently.

DESCRIPTION OF SYMBOLS 10 ... Beam processing apparatus 12 ... Board | substrate 12a, 12b ... Side part 14 ... Casing 16a, 16b ... Air bearing 18 ... Laser 20 ... Rotating polyhedron 22a-22h ... Reflection mirror 19a-19h, 21a-21h, 23a-23h ... Reflection plane 24a-24h ... Prisms 25a-25h, 27a-27h ... Mask members 26a-26h ... Cylindrical lens 28 ... Prisms 29a-29i ... Shading member 30 ... Rotating polyhedron drive motor 31 ... Slit 32 ... Rotating shaft 33 ... Beam spot 34 ... Holder 36 ... Prisms 38a, 38b ... Reflective surfaces 40a-40h ... Cylindrical lens 42 ... Processing parameter setting unit 44 ... Control units 45a, 45b ... Substrate gripping unit 46 ... Laser drive unit 47 ... Substrate moving unit 48 ... Air bearing drive unit 49 ... Substrate moving mechanism 50: optical systems 52 and 54 Isolation trenches 56 and 60 ... beam spot 58a, 58b, 62a, 62b ... wall portion

Claims (16)

In a beam processing apparatus for irradiating a substrate with a beam and processing the substrate,
A beam output source for outputting the beam;
A beam deflector that reflects the beam by a reflection-driven reflection surface and deflects the beam in a main scanning direction of the substrate;
A plurality of first reflectors arranged in the main scanning direction between the reflecting surface and the substrate and having a reflecting plane that reflects the beam reflected and deflected by the reflecting surface;
Corresponding to each of the first reflectors, a plurality of second planes having reflection planes arranged in the main scanning direction and reflecting the beams reflected by the first reflectors and guiding them in the main scanning direction of the substrate. Two reflectors,
A substrate moving mechanism for moving the substrate in a sub-scanning direction different from the main scanning direction;
Each of the first reflectors and the second reflectors is disposed at a position where the optical path lengths of the beams from the beam output source to the substrate are substantially equal. . The beam processing apparatus according to claim 1, wherein
A beam having a condensing characteristic in the sub-scanning direction and condensing the beam on the substrate is disposed between the second reflector and the substrate. Processing equipment. The beam processing apparatus according to claim 2, wherein
Between the second reflector and the first cylindrical lens, a first restricting member that restricts a range of the beam reflected by the second reflector in the sub-scanning direction is disposed. A characteristic beam processing device. The beam processing apparatus according to claim 2 or 3,
Between the second reflector and the first cylindrical lens, a second restricting member for restricting a range of the beam reflected by the second reflector in the main scanning direction is disposed. A characteristic beam processing device. In the beam processing apparatus of any one of Claims 1-4,
Between the reflection surface of the beam deflector and the first reflector, there is a condensing characteristic in a direction orthogonal to the deflection direction of the beam, and corrects the tilt of the reflection surface driven by deflection. A beam processing apparatus comprising a second cylindrical lens. In the beam processing apparatus of any one of Claims 1-5,
An inclination angle α of each first reflector with respect to the main scanning direction, an inclination angle β of each of the second reflectors with respect to the main scanning direction, and an inclination angle γ of the reflecting surface with respect to the main scanning direction are:
β-α ≒ γ
The beam processing apparatus is set according to the relationship of In the beam processing apparatus of any one of Claims 1-6,
The beam processing apparatus, wherein the reflecting surface is constituted by a first prism. In the beam processing apparatus of any one of Claims 1-7,
At least one of the first reflector and the second reflector is constituted by a second prism. In the beam processing apparatus of any one of Claims 1-8,
The beam deflector is a rotating polyhedron having a plurality of the reflecting surfaces that are driven to rotate. In the beam processing apparatus of any one of Claims 1-9,
The beam processing apparatus according to claim 1, wherein the substrate is a solar cell substrate in which a separation groove is processed by the beam. In a substrate processing method of irradiating a substrate with a beam and processing the substrate,
Reflecting the beam output from the beam output source by a reflection-driven reflection surface, deflecting the beam in the main scanning direction of the substrate, and moving the substrate in a sub-scanning direction different from the main scanning direction; ,
Sequentially reflecting the beam reflected by the reflecting surface by a plurality of first reflectors having reflecting planes arranged in the main scanning direction;
Sequentially reflecting the beams reflected by the first reflectors by a plurality of second reflectors having reflection planes arranged in the main scanning direction corresponding to the first reflectors;
Irradiating the beam reflected by each of the second reflectors in the main scanning direction of the substrate, and processing the substrate;
Each of the first reflectors and the second reflectors is disposed at a position where the optical path lengths of the beams from the beam output source to the substrate are substantially equal. Processing method. In the processing method of the board | substrate of Claim 11,
The substrate processing method, wherein the beam reflected by each of the second reflectors is condensed only in the sub-scanning direction and irradiated onto the substrate. In the processing method of the board | substrate of Claim 12,
A substrate processing method, wherein a range of the beam in the sub-scanning direction is restricted and the beam is condensed only in the sub-scanning direction. In the processing method of the board | substrate of Claim 12 or 13,
A substrate processing method, wherein a range of the beam in the main scanning direction is restricted to focus the beam only in the sub-scanning direction. In the processing method of the board | substrate of any one of Claims 11-14,
A method of processing a substrate, wherein the beam deflected and deflected by the reflecting surface is condensed in a direction orthogonal to a deflection direction of the beam and surface tilt correction of the reflecting surface is performed. In the processing method of the board | substrate of any one of Claims 11-15,
The substrate processing method according to claim 1, wherein the substrate is a solar cell substrate in which a separation groove is processed by the beam.

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