JP2009248181A - Laser beam machining apparatus, pitch adjusting method of laser beam, and laser beam machining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining apparatus in which ideal beam branching is possible and in which inter-beam pitch is arbitrarily adjustable, and also to provide a pitch adjusting method of a laser beam and a laser beam machining method. <P>SOLUTION: The laser beam machining apparatus includes a laser beam branching means 21, condensing lenses 22, 23, and an image rotator 24. A single laser beam oscillated from a laser beam oscillator 20 is branched into a plurality of beams, which are emitted to the surface of a workpiece 26 to perform linear machining thereon. In the apparatus, an image rotator is rotated around the optical axis of the beam and, by adjustment of the rotation angle, the pitch spacing of the beam outgoing from the image rotator is adjusted. The invention includes the pitch adjustment of a laser beam by this machining apparatus and the laser beam machining of a workpiece surface using this machining apparatus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laser processing apparatus, a laser beam pitch variable method, and a laser processing method, and more particularly to a laser processing apparatus equipped with an image rotator, a laser beam pitch variable method using the image rotator, and the laser processing apparatus. Related to the laser processing method.

  Conventionally, as a process of performing line-shaped processing on the surface of a workpiece with a laser beam, for example, a processing process of scribing (cutting) into an ITO film, an amorphous silicon film, etc. for forming an electrode film in the production of a thin film solar cell panel In addition, a laser annealing process that applies a laser beam to the silicon film in a line to modify amorphous silicon into polysilicon, and a scribing process that applies a scribing line to divide the chip resistance ceramic substrate into individual chips Etc. are known.

  For example, a thin film solar cell panel is composed of a laminated film in which a transparent electrode film, a silicon film, a metal film, and the like are formed on a glass substrate on which a base layer is formed by CVD or sputtering. These laminated films respond to light and cause battery action. In the battery panel production process, a process of scribing the film surface with a laser beam and connecting the batteries in series is required. The laser device used in this process is usually called a laser scriber. In this scribing process, a laser beam oscillator with a wavelength of about 1 μm or about 0.5 μm is usually used. Although scribing is possible at other wavelengths, in view of the cost of the apparatus, difficulty in acquisition, stability, etc., the laser beam oscillators of the above wavelengths are currently used in many cases.

  In recent years, in the scribing process or the like, it has been proposed to branch a single laser beam into a plurality of beams and perform a line-like processing using the plurality of branched beams. For example, it is known to branch a single laser beam using a diffraction grating (see, for example, Patent Document 1).

  In the scribing process, it is usually necessary not only to split the laser beam, but also to change the pitch between the beams after branching and to adjust the pitch interval according to the processing purpose of the workpiece. However, the beam branched by the diffraction grating is directed to the irradiation lens, and the irradiation lens is designed so that the beam reaches from the direction as perpendicular to the workpiece as possible, but the outer beam is irradiated obliquely. There is a problem that. Therefore, the utilization efficiency of beam energy is low, about 60%. In addition, the diffraction grating cannot be ideally beam-divided, and there is a problem that secondary light that does not always satisfy the diffraction condition is generated.

  FIG. 1 shows an example of beam branching using a diffraction grating. A single laser beam oscillated from the laser beam oscillator 1 is transmitted through the expander 2, reflected by the reflection mirror 3, and then transmitted through the diffraction grating 4 and branched. The branched beam becomes diffracted light from the 0th order to the higher order, and travels toward the irradiation lens 5 while spreading. The beam transmitted through the irradiation lens 5 is designed so as to reach the workpiece 7 through the light shielding mask 6 from the vertical direction as much as possible. However, all the beams are irradiated to the workpiece 7 from the vertical direction. There is a problem that you can't. When the diffraction grating 4 is used, the pitch between the beams can be achieved by rotating the diffraction grating 4, the irradiation lens 5, and the light shielding mask 6 around the optical axis of the beam. There is.

JP 2004-268144 A (claims, etc.)

  An object of the present invention is to solve the above-mentioned problems of the prior art, ideal beam branching can be performed, a beam can be irradiated perpendicularly to a workpiece, and a pitch between beams can be arbitrarily adjusted. An object of the present invention is to provide a laser processing apparatus, a laser beam pitch variable method, and a laser processing method using the laser processing apparatus.

  The laser processing apparatus of the present invention includes a laser beam branching unit, a condenser lens, an image rotator, and an image rotator rotating unit. A single laser beam oscillated from a laser beam oscillator is converted into a plurality of laser beams by the laser beam branching unit. A laser processing apparatus for branching into a beam and irradiating the workpiece surface with the plurality of branched beams to perform a line-like processing on the workpiece surface, wherein the optical axis of the beam is rotated by an image rotator rotating means. The image rotator is rotated around the center, and the pitch interval of the plurality of beams emitted from the image rotator is adjusted by adjusting the rotation angle.

  The laser beam branching means is a polarization beam splitter in which prisms are combined by the number of beams to be branched, and reflectivity that reflects beams of the same intensity to each of a number of prisms that is one less than the number of beams to be branched. A deflecting beam splitter provided with a semi-transmissive film having a transmittance that allows the remaining beam to pass therethrough, and a total reflection film is provided on the remaining one prism. Preferably there is.

  The laser beam branching means is also composed of a combination of at least one partial reflection mirror less than the number of beams to be branched and at least one total reflection mirror, and the partial reflection mirror reflects a beam having the same intensity. It may be a beam splitter configured to have a transmittance and to transmit the remaining beam.

  The said condensing lens should just be installed in the upstream or downstream of the image rotator on the optical path of a laser beam.

  According to the laser processing apparatus configured as in the previous period, ideal beam branching can be performed, the beam can be irradiated perpendicularly to the workpiece, and the pitch between the beams can be arbitrarily adjusted.

  The laser beam pitch variable method of the present invention uses a laser processing apparatus having a laser beam branching means, a condensing lens, an image rotator, and an image rotator rotating means, and a single laser beam oscillated from a laser beam oscillator, The laser beam is split into multiple beams by the laser beam splitting means, the split multiple beams are incident on the image rotator, and the image rotator is rotated by the image rotator rotating means to adjust the rotation angle. Thus, the pitch interval of the plurality of beams emitted from the image rotator is adjusted.

  In the laser beam pitch variable method, the laser beam branching is a polarization beam splitter formed by combining prisms by the number of beams to be branched, and is the same for each of the number of prisms that is one less than the number of beams to be branched. An optical semi-transmissive film having a reflectivity for reflecting an intense beam and a transmittance for transmitting the remaining beam is provided, and the remaining one prism has a total reflection film. The partial reflection mirror is configured by using a laser beam branching means, which is a polarizing beam splitter, or a combination of at least one partial reflection mirror less than the number of beams to be branched and at least one total reflection mirror. Has a reflectivity that reflects the beam of the same intensity and a transmission that transmits the remaining beam Is preferably carried out using a laser beam splitting means is configured to have a.

  In the laser beam pitch variable method, a plurality of branched beams are transmitted through a condenser lens and incident on an image rotator, or alternatively, a beam emitted from the image rotator is transmitted through a condenser lens. May be.

  In this pitch variable method, after the beam is branched, the image rotator is rotated by a predetermined angle, so that the beam irradiated to the workpiece can be an ideal branched beam, and the pitch between the beams can be arbitrarily adjusted. And can be varied. Further, ideal beam branching can be performed, and the beam can be irradiated perpendicularly to the workpiece.

  The laser processing method of the present invention is a method of processing the surface of a workpiece into a line shape using a laser beam, wherein a single laser beam oscillated from a laser beam oscillator is converted into a plurality of beams by a laser beam branching means. Divide the beam, make the branched beams incident on the image rotator, rotate the image rotator around the optical axis of the beam by the image rotator rotation means, and adjust the rotation angle to adjust the pitch interval from the image rotator The plurality of beams thus emitted are emitted, and the surface of the workpiece is irradiated with the thus-adjusted pitch-adjusted beams so as to be processed into a line shape.

  In the laser processing method of the present invention, a laser beam is a polarization beam splitter in which prisms are combined by the number of beams to be branched, and each of the number of prisms one less than the number of beams to be branched has the same intensity. Is provided with a semi-transparent film having a reflectivity that reflects the beam of the light and a transmittance that allows the remaining beam to be transmitted, and the remaining one prism is provided with a total reflection film. The polarization beam splitter is a combination of at least one partial reflection mirror and at least one total reflection mirror using the laser beam branching means, or the number of beams to be branched. Has reflectivity to reflect the same intensity beam, and has the transmittance to transmit the remaining beam It is preferably carried out using a laser beam branching means configured to.

  In the laser processing method of the present invention, a plurality of branched laser beams are allowed to enter the image rotator after passing through the condenser lens, or the beam emitted from the image rotator is allowed to pass through the condenser lens. What is necessary is just to irradiate the surface of a workpiece.

  By rotating the image rotator by a predetermined angle by the process configured as described above, the beam irradiated to the workpiece can be irradiated as an ideal branch beam perpendicularly to the workpiece, and the pitch between the beams Can be arbitrarily adjusted and varied, so that the workpiece can be arbitrarily processed into a line according to the purpose.

  According to the present invention, an ideal branch of a laser beam can be performed, the beam can be irradiated perpendicularly to the workpiece, the pitch between the beams can be arbitrarily adjusted, and the workpiece can be arbitrarily selected according to the purpose. There is an effect that it can be processed into a line shape.

  According to a preferred embodiment of the laser processing apparatus according to the present invention, it has a laser beam branching means, a condenser lens, an image rotator configured to be rotatable, and an image rotator rotating means. A polarization beam splitter formed by combining prisms by the number of beams to be branched, and having a reflectivity for reflecting the same intensity beam to each of the number of prisms one less than the number of beams to be branched, and the remaining A beam that is provided with a translucent film configured to transmit the beam and a remaining beam is provided with a total reflection film, or a beam to be branched A combination of at least one partial reflection mirror and at least one total reflection mirror This partially reflecting mirror is a beam splitter that has a reflectivity that reflects a beam of the same intensity and a transmittance that transmits the remaining beam, and is oscillated from a laser beam oscillator. A single laser beam is split into a plurality of beams by the laser beam splitting means, the split multiple beams are made incident on the image rotator, and the image rotator is rotated around the optical axis of the beam by the image rotator rotating means. The beam is rotated by a predetermined angle, and a beam with an adjusted pitch interval is emitted from the image rotator, and the beam with the adjusted pitch is irradiated perpendicularly to the surface of the workpiece to perform a line-like processing on the surface of the workpiece. A laser processing apparatus is provided.

  When the condensing lens is installed on the upstream side of the image rotator and the downstream side of the laser beam branching means on the optical path of the laser beam, the plurality of beams branched by the beam branching means are condensed. It is configured to transmit the lens and enter the image rotator, rotate the image rotator by a desired angle around the optical axis of the beam, and adjust the pitch angle of the beam emitted from the image rotator by adjusting the rotation angle Has been.

  In addition, when the condenser lens is installed on the optical path of the laser beam, downstream of the image rotator and in front of the workpiece, the plurality of beams branched by the laser beam branching means are imaged. Incident light enters the rotator, and the image rotator rotating means rotates the image rotator by a desired angle around the optical axis of the beam, and adjusts the rotation angle to adjust the pitch interval of the beam emitted from the image rotator. The beam with the adjusted spacing is configured to pass through the condenser lens.

  According to the laser processing apparatus configured as described above, ideal beam branching can be performed, the workpiece can be irradiated vertically, and the pitch between the beams can be arbitrarily adjusted.

  The laser beam branching means is not particularly limited, and a polarizing beam splitter using a prism described in detail below or a beam splitter formed by combining a total reflection mirror and a partial reflection mirror can be used.

  For example, as described above, as a polarizing beam splitter, each of the number of prisms, which is one less than the number of beams to be branched, has a reflectivity that reflects the same intensity beam, and transmits the remaining beams. It is possible to use a beam splitter in which a light semi-transmissive film configured to have a transmissivity is provided, and the remaining one prism is provided with a total reflection film.

That is, as shown in FIG. 2A, the laser beam branching is a deflecting beam splitter in which a single beam oscillated from the laser beam oscillator 20 is combined with the number of prisms having desired dimensions as many as desired. The beam can be branched using the means 21. In this case, as each prism, a prism provided with a semi-transmissive film having a desired ratio of reflectance and transmittance may be used. As shown in FIG. 2 (a), is partially reflected by the first prism P ₁ to form a line A _1, and the beam transmitted through the first prism P ₁ is partially reflected by the second prism P ₂ The line B ₁ is formed, the beam transmitted through the second prism P ₂ is partially reflected by the third prism P ₃ to form the line C ₁ , and the beam transmitted through the third prism P ₃ is the fourth beam by partially reflected by the prism P ₄ form a line D _1, the beam passing through the fourth prism P ₄ by partially reflective to form a line E ₁ a prism P ₅ of the fifth, and fifth prism P _The beam transmitted through ₅ is totally reflected by the sixth prism P ₆ to form the line F _1, and can be branched by a desired number. In FIG. 2A, the case of branching to 6 is illustrated, but it is possible to branch to the target number by appropriately selecting the size of the prism and the diameter of the lens. What is necessary is just to design suitably about the reflectance and the transmittance | permeability of each prism so that the intensity | strength of each beam formed by branching may become equal.

  In the present invention, as described above, the laser beam branching means is configured by combining at least one partial reflection mirror less than the number of beams to be branched and at least one total reflection mirror, and the partial reflection mirrors are the same. Bifurcation means can be used that have a reflectivity that reflects the beam of intensity and that has a transmittance that transmits the remaining beam. For example, as shown in FIGS. 3 (a) and 4 (a), a beam splitter in which a predetermined number of total reflection mirrors and partial reflection mirrors are arranged at predetermined intervals in a predetermined order at a predetermined angle. It may be used to split the beam.

As shown in FIG. 3A, a single beam oscillated from a laser beam oscillator is partially transmitted by a _first partial reflection mirror M ₁ disposed along the optical path of the laser beam to form a line A ₂ . Then, the beam reflected by the partial reflection mirror M ₁ is partially reflected by the second partial reflection mirror M ₂ to form a line B ₂ , and the beam transmitted through the second partial reflection mirror M ₂ is partially reflected by the partial reflection mirror M. ₃ is partially reflected to form a line C ₂ , and the beam transmitted through the third partial reflection mirror M ₃ is partially reflected by the fourth partial reflection mirror M ₄ to form a line D ₂ . The beam transmitted through the partial reflection mirror M ₄ is reflected by the total reflection mirror M ₅ to form a line E _2, and can be branched by a desired number. In FIG. 3A, the case of branching to 5 is illustrated, but it is possible to branch to the desired number of processing beams by appropriately selecting the size and number of partial reflection mirrors and the angle of arrangement. What is necessary is just to design suitably about the reflectance and the transmittance | permeability of each reflection mirror so that the intensity | strength of each beam formed by branching may become equal.

  Further, as shown in FIG. 4A, a predetermined number of total reflection mirrors and partial reflection mirrors arranged in a predetermined order at equal intervals and at a predetermined angle are set as a set. The beam may be branched using a beam splitter that is arranged symmetrically with respect to the optical axis of the beam.

As shown in FIG. 4A, first, a single beam oscillated from a laser beam oscillator is partially reflected and partially transmitted by a _first partially reflecting mirror R ₁ arranged along the optical path of the laser beam. . Next, the transmitted beam is partially transmitted through the second partially reflecting mirror R ₂ to form a line A ₃ , and the beam reflected by the second partially reflecting mirror R ₂ is reflected by the third partially reflecting mirror R ₃ . A line B ₃ is formed by partial reflection, and a beam transmitted through the third partial reflection mirror R ₃ is partially reflected by the fourth partial reflection mirror R ₄ to form a line C _3, thereby forming a fourth partial reflection. and so form a line D ₃ by reflecting beam is transmitted through the mirror R ₄ by the total reflection mirror R ₅ of the fifth, it can be allowed to branch desired number. Further, the beam partially reflected by the first partial reflection mirror R ₁ is partially reflected by the sixth partial reflection mirror R ₆ to form a line E ₃ , and the beam transmitted through the sixth partial reflection mirror R _6. Is partially reflected by the seventh partial reflection mirror R ₇ to form a line F ₃ , and the beam transmitted through the seventh partial reflection mirror R ₇ is reflected by the eighth total reflection mirror R ₈ to produce a line G _3. The desired number of branches can be branched.

  In FIG. 4 (a), the case of branching into a total of seven is illustrated, but by selecting the dimensions and number of total reflection mirrors and partial reflection mirrors, the angle of arrangement, and the number of sets as appropriate, The number of processing beams can be branched. What is necessary is just to design suitably about the reflectance and the transmittance | permeability of each reflection mirror so that the intensity | strength of each beam formed by branching may become equal.

  FIGS. 3A and 4A exemplify preferable arrangements of the total reflection mirror and the partial reflection mirror constituting the beam splitter. However, other arrangements may be used as long as the laser beam is equally branched. Of course, it may be arranged.

  The condensing lens is arranged on the upstream side (FIG. 2A) or the downstream side of the image rotator described below along the optical path of the laser beam, and condenses each beam of the branched beam as described above. The beam is made incident on the image rotator, or each beam of the branched beam is made incident on the image rotator, and then the beam with the adjusted pitch interval emitted from the image rotator is condensed to be a beam spot on the work surface. Are formed in a predetermined shape. The beam emitted from the image rotator passes through the irradiation lens bar and reaches the surface of the workpiece, and processes the surface into a line shape.

  As the image rotator (image rotator), polo type and roof type upright prisms can be used in the present invention, and a roof type prism is preferable. This roof prism is a prism having a pair of reflecting surfaces that intersect at a nominal surface angle of 90 degrees, and can reverse the image. When this image rotator is rotated by φ degrees around the optical axis of the laser beam, the beam emitted from the image rotator is rotated by 2 φ degrees. On the other hand, the diffraction grating forms an interference fringe by splitting light by diffraction and interference, and the interference fringe pattern can be changed by changing the distance between the grating and the screen.

  The workpiece is not particularly limited. For example, a transparent electrode film such as an ITO film, a silicon film, a metal film, or the like when a thin film solar cell panel is manufactured, or amorphous silicon is modified into polysilicon by laser annealing. In this case, a silicon thin film or a ceramic substrate having a chip resistance when divided into individual chips can be used. These workpieces are irradiated with a laser beam whose pitch interval is adjusted, and a scribing process is performed to perform line-shaped processing.

  FIGS. 2A to 2D show the optical path of the laser beam from the laser beam oscillator to the workpiece when the condenser lens is installed upstream of the image rotator and downstream of the laser beam branching means. ) Will be described.

  As shown in FIG. 2A, the single laser beam oscillated from the laser beam oscillator 20 is branched into the target number of beams by the laser beam branching means 21 as described above (FIG. 2A). 6), the lens 22 and the lens 23 are then transmitted and incident on the roof prism as the image rotator 24.

  When the beam branched as described above is incident on the image rotator 24 and the image rotator 24 is rotated around the optical axis of the beam by a desired angle φ degree by the image rotator rotating means, the image rotator 24 rotates 2φ. An image (beam) rotated by a certain degree is emitted. By adjusting the rotation angle, the pitch interval of the beams can be changed as will be described later. The beams emitted from the image rotator 24 pass through the irradiation lens bar 25 while maintaining a state parallel to each other, and reach the processing surface of the workpiece 26 as they are (FIGS. 2A and 2B). If the irradiation lens bar 25 is arranged perpendicular to the scribing direction, the pitch between the beam centers, which is the distance from the center of one beam to the center of the adjacent beam, is maximized (FIG. 2 (c)). If the lens bar 25 is arranged with a predetermined inclination with respect to the scribing direction, the pitch between the beam centers changes (FIG. 2D). The pitch between the beam centers is θ = 60 degrees and becomes the minimum pitch. In this case, the rotation angle φ of the image rotator 24 may be 30 degrees.

  As for the spot position of the laser beam that has reached the processing surface of the workpiece as described above, the beam splitter shown in FIG. 3A is shown in FIG. 3B, and the beam splitter shown in FIG. Is shown in FIG. Moreover, the spot position of a general laser beam is shown to Fig.5 (a)-(c). In each figure, the horizontal axis is the X axis, and the vertical axis is the Y axis (longitudinal scribing direction).

  3 (b) and 4 (b), ◯ represents the spot position of the laser beam (after θ-degree rotation) on the processed surface, ◯ of the phantom line represents the spot position before the rotation, and D ′ represents the distance between the beams. P represents the pitch, and O represents the center of rotation. In FIG. 5A showing the spot position before rotation, O represents the center of rotation, ○ represents the spot position of the laser beam on the processed surface before rotation, and D represents the inter-beam pitch. In FIG. 5B showing the spot position after rotation, O represents the center of rotation, ◯ represents the spot position of the laser beam on the processed surface after θ rotation, and ◯ of the imaginary line represents the spot position before rotation. , D represents the inter-beam pitch, D ′ represents the beam spot position after θ rotation, and the relationship D ′ = D cos θ holds. In FIG. 5C showing the spot position after rotation, O represents the center of rotation, and ◯ represents the spot position after being rotated by approximately 90 degrees.

  FIG. 3 (b) shows that when the image rotator is rotated by θ degrees in the optical system of FIG. 3 (a), the distance between adjacent beam spots on the processing surface is variable compared to the distance before rotation. It shows that. Also in the case of FIG. 4B, when the image rotator is rotated by θ degrees in the optical system of FIG. 4A, the distance between adjacent beam spots on the processing surface is compared with the distance before the rotation. It shows that it is variable.

  FIG. 5A schematically shows a state in which a large number of beams optically branched in advance are collected in a spot shape via an image rotator and an irradiation lens and arranged in series. . As is clear from FIG. 5A, if the beam spots are aligned at equal intervals in the X-axis direction, parallel markings can be drawn parallel to the Y-axis by moving in parallel in the Y-axis direction. it can. Next, when it is desired to change the pitch between the beams in the X-axis direction, if a rotation operation is performed by a predetermined angle around the optical axis of the beam at the rotation center O shown in FIG. It will be in the state shown automatically. As shown in FIG. 5 (b), if the rotation angle is fixed by θ, the rotation angle is maintained, and the translation is performed in the Y-axis direction, the distance between the beam spots (D ′) and the distance between the beams ( D) has a relationship satisfying the following expression as described above.

D ′ = D · cos θ
In the above equation, D is the beam pitch (maximum pitch) when θ = 0 degrees, and θ is the rotation angle (the rotation direction may be either counterclockwise or clockwise). As is clear from FIG. 5C, the beam pitch is minimized when θ = ˜90 degrees.

  Further, the number of branched beams may be an even number or an odd number, and the rotation target may be an axis.

  According to a preferred embodiment of the laser beam pitch variable method according to the present invention, a laser beam processing device having a laser beam branching unit, a condenser lens, an image rotator, and an image rotator rotating unit is used and is oscillated from a laser beam oscillator. A single laser beam is split into a plurality of beams by a laser beam splitting means, and the split multiple beams are incident on an image rotator, and an image is rotated around the optical axis of the beam by an image rotator rotating means. By rotating the rotator and adjusting the rotation angle, a pitch variable method for adjusting the pitch interval of a plurality of beams emitted from the image rotator is provided. In this case, the polarization beam splitter as described above is used as a laser beam branching unit. And total reflection mirror and part After splitting into a desired number of beams by using a beam splitter which is arbitrarily combined with a reflecting mirror, a plurality of branched beams are transmitted through a condenser lens and incident on an image rotator or branched. A plurality of beams may be incident on the image rotator, and the plurality of beams emitted from the image rotator may be transmitted through the condenser lens.

  Thus, by rotating the image rotator by a predetermined angle, the beam irradiated to the workpiece can be made an ideal branch beam, the branch beam can be irradiated perpendicularly to the workpiece, and the pitch between the beams can be increased. It can be arbitrarily adjusted and varied.

  The laser beam branching means, the condensing lens, the image rotator, and the like in this laser beam pitch variable method are as described in the above laser processing apparatus.

  According to a preferred embodiment of the laser processing method of the present invention, in a method of processing the surface of a workpiece into a line shape using a laser beam, a single laser beam oscillated from a laser beam oscillator is converted into a laser. Using the polarization beam splitter as described above as a beam branching unit or a beam splitter formed by arbitrarily combining a total reflection mirror and a partial reflection mirror, the beam is branched into a plurality of beams, and the plurality of the branched beams are image rotators. The image rotator is rotated around the optical axis of the beam, and a plurality of beams with adjusted pitch intervals are emitted from the image rotator by adjusting the rotation angle, and the pitch intervals thus obtained are adjusted. Provides a method to irradiate the surface of the workpiece with the beam of the workpiece and process it into a line In this case, a plurality of branched beams are transmitted through the condensing lens and incident on the image rotator, and then the surface of the workpiece is irradiated with the beam with the adjusted pitch interval emitted from the image rotator. A plurality of branched beams may be incident on the image rotator, and the beam emitted from the image rotator may be irradiated to the surface of the workpiece after passing through the condenser lens.

  Thus, by rotating the image rotator by a predetermined angle, the beam irradiated to the workpiece can be made an ideal branch beam, the branch beam can be irradiated perpendicularly to the workpiece, and the pitch between the beams can be increased. Since it can be arbitrarily adjusted and varied, the workpiece can be arbitrarily processed into a line according to the purpose.

  The laser beam branching means, the condensing lens, the image rotator and the like in this laser processing method are as described in the above laser processing apparatus.

  The laser processing apparatus described above is installed on the tip side of the laser beam oscillator to perform laser processing.

In the present invention, the image rotator is rotated about the optical axis of the beam by the image rotator rotating means, and the pitch interval of the plurality of beams emitted from the image rotator is adjusted by adjusting the rotation angle. The pitch interval of the plurality of beams can be adjusted in the same manner by rotating the components of the laser processing apparatus such as the bar and the laser beam branching means and adjusting the rotation angle. In the case of rotation of the laser beam branching means, there is no need for an image rotator.

  According to the present invention, ideal beam branching can be performed, the branch beam can be irradiated perpendicularly to the workpiece, and the pitch between the beams can be arbitrarily adjusted. , A scribing process for electrode film formation, a laser annealing process in which a laser beam is applied to the silicon film in a line to modify amorphous silicon into polysilicon, and a chip resistor ceramic substrate is divided into individual chips. For example, a scribing process for applying a scribing line can be used in the technical field of processing with a laser beam.

Schematic explanatory drawing for demonstrating the beam branch of the prior art using a diffraction grating. The typical explanatory view for explaining the optical path of the beam in the laser processing device of the present invention. The typical block diagram which shows one Embodiment of the beam splitter used by this invention. The typical block diagram which shows another embodiment of the beam splitter used by this invention. The typical explanatory view for explaining the spot position of the laser beam in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser beam oscillator 2 Expander 3 Reflection mirror 4 Diffraction grating 5 Irradiation lens 6 Shading mask 7 Work piece 20 Laser beam oscillator 21 Laser beam branch means 22, 23 Condensing lens 24 Image rotator 25 Irradiation lens bar 26 Work piece P ₁ to P ₆ first through sixth prism a ₁ to F ₁ line _M 1 ~M ₄ first to fourth partial reflection mirror M ₅ a total reflection mirror _a 2 to E ₂ line a ₃ ~G ₃ lines _R 1 to R ₄ , R ₆ , R ₇ partial reflection mirror R ₅ , R ₈ total reflection mirror

Claims (12)

A laser beam branching means, a condenser lens, an image rotator, and an image rotator rotating means. A single laser beam oscillated from a laser beam oscillator is split into a plurality of beams by the laser beam branching means. A laser processing apparatus for irradiating a workpiece surface with a plurality of beams that are processed to form a line on the workpiece surface, wherein the image rotator rotates around the optical axis of the beam by the image rotator rotating means The laser processing apparatus is configured to adjust the pitch interval of the plurality of beams emitted from the image rotator by adjusting the rotation angle. The laser beam branching means is a polarization beam splitter in which prisms are combined by the number of beams to be branched, and reflectivity that reflects beams of the same intensity to each of a number of prisms that is one less than the number of beams to be branched. A deflecting beam splitter provided with a semi-transmissive film having a transmittance that allows the remaining beam to pass therethrough, and a total reflection film is provided on the remaining one prism. The laser processing apparatus according to claim 1, wherein: The laser beam branching means is configured by combining at least one partial reflection mirror less than the number of beams to be branched and at least one total reflection mirror, and the partial reflection mirror reflects the beam having the same intensity. 2. The laser processing apparatus according to claim 1, wherein the beam processing apparatus is configured to have a transmittance that allows the remaining beam to pass therethrough. The laser processing apparatus according to claim 1, wherein the condensing lens is installed on the upstream side or the downstream side of the image rotator on the optical path of the laser beam. Using a laser processing apparatus having a laser beam branching means, a condenser lens, an image rotator, and an image rotator rotating means, a single laser beam oscillated from a laser beam oscillator is converted into a plurality of beams by the laser beam branching means. The beam is branched, the branched beams are incident on the image rotator, the image rotator is rotated by the image rotator rotating means around the optical axis of the beam, and the rotation angle is adjusted to be emitted from the image rotator. A method of changing the pitch of a laser beam, characterized by adjusting a pitch interval of a plurality of beams. The laser beam is a polarization beam splitter in which prisms are combined by the number of beams to be branched, and the reflectivity reflects the same intensity beam to each of the number of prisms that is one less than the number of beams to be branched. And a polarizing beam splitter in which a translucent film configured to transmit the remaining beam is provided, and the remaining one prism is provided with a total reflection film. It is constructed by using a laser beam branching means or a combination of at least one partial reflection mirror less than the number of beams to be branched and at least one total reflection mirror, and this partial reflection mirror reflects a beam having the same intensity. A laser that has reflectivity and is configured to have a transmittance that transmits the remaining beam Variable pitch method of laser beam according to claim 5, wherein the performed using chromatography beam splitting means. 7. The laser beam pitch varying method according to claim 5, wherein the plurality of branched beams are transmitted through a condenser lens and incident on an image rotator. 7. The laser beam pitch variable method according to claim 5, wherein the beam emitted from the image rotator is transmitted through a condenser lens. In a method of processing a surface of a workpiece into a line shape using a laser beam, a single laser beam oscillated from a laser beam oscillator is branched into a plurality of beams by a laser beam branching means, and the branched plurality The image rotator is caused to enter the image rotator, the image rotator is rotated about the optical axis of the beam by the image rotator rotating means, and the rotation angle is adjusted so that a plurality of beams whose pitch intervals are adjusted are adjusted from the image rotator. A laser processing method characterized by emitting a beam having a pitch interval thus adjusted and irradiating the surface of the workpiece to process it into a line shape. The laser beam is a polarization beam splitter in which prisms are combined by the number of beams to be branched, and the reflectivity reflects the same intensity beam to each of the number of prisms that is one less than the number of beams to be branched. And a polarizing beam splitter in which a translucent film configured to transmit the remaining beam is provided, and the remaining one prism is provided with a total reflection film. It is constructed by using a laser beam branching means or a combination of at least one partial reflection mirror less than the number of beams to be branched and at least one total reflection mirror, and this partial reflection mirror reflects a beam having the same intensity. A laser that has reflectivity and is configured to have a transmittance that transmits the remaining beam Laser processing method according to claim 9, he characterized in that it is carried out using a chromatography beam splitting means. 11. The laser processing method according to claim 9, wherein the plurality of branched laser beams are incident on an image rotator after passing through a condenser lens. 11. The laser processing method according to claim 9, wherein a beam emitted from the image rotator is irradiated on a workpiece surface after passing through a condenser lens.

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