JP2010142834A - Laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform laser beam machining of an object to be machined with excellent positional accuracy irrespective of the position where the object is placed and the inclination of the object. <P>SOLUTION: A laser beam machining apparatus comprises: an object conveying means 2 for conveying the object 1 to be machined in the first direction at fixed speed; a position detection means 3 for detecting the position of the object 1 on the object conveying means 2; a laser beam oscillator 4, a deflecting means 6 for deflecting the laser beam B by adjusting the deflecting direction of the laser beam B output from the laser beam oscillator 4 in the direction parallel to the first direction; a scanning means 7 for performing the scanning in the predetermined scanning direction at fixed speed with respect to a surface to be machined by deflecting the laser beam B deflected by the deflecting means 6; a control means 8 for controlling the deflecting direction of the laser beam B in the deflecting means 6 on the basis of the result of detection of the position of the object 1 on the object conveying means 2 detected by the position detection means 3 and information on the conveying position of the object 1; and a condensing means 9 for condensing the laser beam B deflected by the deflecting means 6 and the scanning means 7 on the surface to be machined. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laser processing apparatus for processing a processing target by irradiating the processing target with a laser beam.

  Conventionally, a laser processing apparatus that processes a processing target by irradiating the processing target with a laser is widely used. For example, a processing object transporting means for transporting a processing object and a laser beam scanning means for scanning a laser beam are provided, and the laser beam scanning means moves the processing object in one direction at a constant speed by the processing object transporting means. When processing by scanning the laser, the angle between the laser beam scanning direction and the transport direction is changed according to the transport speed of the object to be processed, so that laser processing is performed in a straight line perpendicular to the transport direction regardless of the transport speed. There is a laser processing apparatus that performs (see, for example, Patent Document 1).

JP 2001-259869 A

  However, according to the above-described conventional technique, when laser processing is performed by setting a processing target on the processing target transport unit, the processing target is displaced due to the position shift of the processing target on the installation surface of the transport unit and the rotation direction inclination. There has been a problem that the laser processing position in is displaced.

  The present invention has been made in view of the above, and provides a laser processing apparatus capable of performing laser processing with high positional accuracy on a processing target regardless of the position and inclination of the processing target. With the goal.

  In order to solve the above-described problems and achieve the object, a laser processing apparatus according to the present invention holds a processing target with the processing surface facing up, and moves the processing target in a first direction at a constant speed. A processing object transporting means for transporting, a position detection means for detecting the position of the processing object on the processing object transporting means, a laser oscillator for outputting a laser beam, and a deflection direction of the laser beam output from the laser oscillator In a direction parallel to the first direction to deflect the laser beam, and deflect the laser beam deflected by the deflecting means in a predetermined scanning direction with respect to the processing surface. Scanning means for scanning at a constant speed, detection result of the position of the processing target on the processing target transport means detected by the position detection means, and the processing target transport means And a control means for controlling a deflection direction of the laser beam in the deflection means based on the information on the conveyance position of the machining target, and the laser beam deflected by the deflection means and the scanning means on the work surface. And a condensing means for condensing the light.

  According to this invention, it is possible to adjust the deflection direction of the laser beam in a direction parallel to the first direction in which the processing target is transported based on the position of the processing target on the processing target transporting means. There is an effect that laser processing can be performed with respect to the processing object with high positional accuracy regardless of the position and inclination of the mounting.

  Embodiments of a laser processing apparatus according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings.

Embodiment FIG. 1 is a schematic diagram for explaining a schematic configuration of a laser processing apparatus according to an embodiment of the present invention. The laser processing apparatus according to this embodiment includes a processing object transport unit 2, a position detection unit 3, a laser oscillator 4, a laser beam shaping unit 5, a deflection unit 6, a scanning unit 7, a control unit 8, and the like. Condensing means 9 is provided.

  The processing target transport unit 2 holds the processing target 1 with the processing surface facing up, and transports the processing target 1 at a constant speed in the transport direction that is the first direction. For example, a belt conveyor or the like is used as the processing object transport unit 2. Further, the processing target transport unit 2 generates information (position signal) related to the transport position of the processing target 1 and transmits the information to the control unit 8.

  The position detection unit 3 detects the position of the processing target 1 on the processing target transport unit 2. The position detection means 3 is provided at two places, for example, and detects the position of the workpiece 1 at two points. The laser oscillator 4 outputs a laser beam B.

  The laser beam shaping means 5 shapes the laser beam B output from the laser oscillator 4 so as to have a desired laser pattern at the machining point of the surface to be machined 1. As the laser beam shaping means 5, for example, a diffractive optical element can be used. Note that it is also possible to form the laser beam B using an opening having a desired shape instead of the laser beam shaping means 5.

  The deflection unit 6 deflects the laser beam B by adjusting the deflection direction of the laser beam B shaped by the laser beam shaping unit 5 in a direction parallel to the transport direction. For example, a galvanometer mirror is used as the deflecting means 6. Hereinafter, it is referred to as a galvanometer mirror 6. By having the galvanometer mirror 6 in this way, in the laser processing apparatus according to the present embodiment, the laser beam B shaped by the laser beam shaping means 5 is arbitrarily adjusted and deflected in a direction parallel to the transport direction. It is possible.

  The scanning means 7 deflects the laser beam B deflected by the galvanometer mirror 6 and scans the surface to be processed at a constant speed in a predetermined scanning direction. For example, a polygon mirror is used as the scanning unit 7, and the mirror is rotated in a certain direction, and the laser beam B deflected by the galvano mirror 6 is scanned in a direction substantially orthogonal to the carrying direction, for example. Hereinafter, it is referred to as a polygon mirror 7.

  Based on the detection result of the position of the processing target 1 on the processing target transport unit 2 detected by the position detection unit 3 and information on the transport position of the processing target 1 by the processing target transport unit 2, the control unit 8 controls the galvano mirror 6. The deflection direction of the laser beam B is controlled. The control unit 8 has information (setting position information) regarding the installation position of the processing target 1 on the processing target transport unit 2 set in advance, and the control unit 8 sets the detection result and setting by the position detection unit 3. Based on the position information, it is possible to obtain information related to the positional deviation of the workpiece 1 that is actually arranged with respect to the set position and the tilt in the rotation direction (hereinafter referred to as tilt). Further, the control unit 8 acquires information (position signal) related to the transport position of the processing target 1 from the processing target transport unit 2. Thereby, the control means 8 controls the deflection direction of the laser beam B in the galvanometer mirror 6 on the basis of the information on the positional deviation and the inclination and the information (position signal) about the transport position of the processing object 1, thereby processing the processing position. Is corrected to prevent the displacement of the processing position due to the displacement or inclination of the installation position of the processing object 1.

  The condensing unit 9 condenses the laser beam B deflected by the polygon mirror 7 on the surface to be processed of the processing target 1. For the light condensing means 9, for example, an Fθ lens is used. Hereinafter, it is referred to as an Fθ lens 9.

  Next, the processing by the laser processing apparatus according to the present embodiment is performed by using an electrode (hereinafter referred to as a narrow contact) only on a part of the back surface of the polycrystalline silicon solar cell (the surface on the sunlight incident side is the surface). An example of forming the case will be described. In a conventional general polycrystalline silicon solar cell, a contact structure (electrode structure) for taking out current is formed on the entire back surface. In this case, the recombination loss of carriers on the back side of the polycrystalline silicon substrate for the polycrystalline silicon solar cell, the distortion due to the difference in the linear expansion coefficient between the electrode material and the polycrystalline silicon substrate, etc. occur, and the photoelectric conversion efficiency In addition, there are problems with durability and reliability.

  However, in a polycrystalline silicon solar cell having a structure with narrow contacts, the recombination loss of carriers is reduced by the passivation effect of the insulating film that occupies most of the back surface of the polycrystalline silicon substrate, and the photoelectric conversion efficiency is improved. Can do. In addition, by forming a narrow contact only on the laser opening, which is a limited area, on the back surface of the polycrystalline silicon substrate, the linear expansion between the electrode material and the polycrystalline silicon substrate occurs when the electrode is formed on the entire surface. Since distortion caused by the difference in coefficient can be reduced, durability and reliability are improved. Below, the formation process of a narrow contact is demonstrated with reference to FIGS. 2-1 to 2-3 among the manufacturing processes of a polycrystalline-silicon solar cell. FIGS. 2-1 to 2-3 are schematic views for explaining a process for forming a narrow contact of a polycrystalline silicon solar cell. FIGS. 2-1 to 2-3 show only members directly related to the explanation of the present invention.

First, the flow of the narrow contact forming process will be described. First, an insulating film 12 is formed on the entire back surface of a polycrystalline silicon substrate 11 for a polycrystalline silicon solar cell (FIG. 2-1). For example, a silicon nitride film (Si ₃ N ₄ ) can be used as the insulating film 12. Next, a laser opening 13 is formed in the insulating film 12 by the laser processing apparatus according to the present embodiment (FIG. 2-2). The pattern of the laser aperture 13 at this time is a straight line with an equal interval. Subsequently, an electrode paste is printed on the laser opening 13, and the polycrystalline silicon substrate 11 is heated to sinter the electrode paste to form narrow contacts 14 (FIG. 2-3). As described above, the narrow contact 14 can be formed on the back surface of the polycrystalline silicon substrate 11.

  Next, a method of processing 36 linear laser openings 13 having a pitch of 4 mm, for example, using the laser processing apparatus according to the present embodiment in order to form the narrow contact 14 described above will be described. The width of the straight line to be laser processed is set to 40 μm, for example. The pitch and the width of the laser aperture 13 are merely representative values, and the light of the polycrystalline silicon solar cell to be fabricated depends on various conditions such as the characteristics of the insulating film 12 and the polycrystalline silicon substrate 11 to be used. -Adjust the electrical conversion efficiency so that it is optimal. The effect of the present invention is effective even if the pitch and the width of the laser aperture 13 are changed.

  Here, the object to be processed 1 is an insulating film 12 formed on the back surface of a substantially rectangular polycrystalline silicon substrate 11 of 150 mm square. The laser oscillator 4 uses a third harmonic of a Q-switched LD-pumped solid-state laser. The wavelength of the laser beam B is 355 nm. By selecting a wavelength with a short penetration length of the insulating film 12 and silicon on the polycrystalline silicon substrate 11, the polycrystalline silicon substrate 11 can be processed with less deterioration due to laser beam B irradiation. Since the Q-switched LD-pumped solid-state laser has a relatively high repetition frequency of several tens of kHz, the pulse energy is large, and the peak power is high, it can be processed into the insulating film 12 with a large area by a single laser pulse. Processing is possible.

  The laser beam B output from the laser oscillator 4 is shaped by the laser beam shaping means 5 and enters the galvanometer mirror 6. The laser beam B incident on the galvanometer mirror 6 is deflected by the control means 8 with its deflection direction adjusted in a direction parallel to the transport direction, and incident on the polygon mirror 7. The laser beam B incident on the polygon mirror 7 is deflected and scanned in a direction substantially perpendicular to the transport direction. More specifically, the laser beam B is scanned in a direction substantially orthogonal to a side of the substantially rectangular polycrystalline silicon substrate 11 in a direction substantially parallel to the transport direction.

  The laser beam B deflected and scanned by the polygon mirror 7 is condensed on the processing surface of the processing object 1 by the Fθ lens 9. At a portion of the processing surface irradiated with the laser beam B, a laser opening 13 is formed in the insulating film 12 on the polycrystalline silicon substrate 11 that is the processing target 1 by laser ablation.

  When the processing target 1 is installed on the processing target transport unit 2, the actual installation position 22 of the processing target 1 on the processing target transport unit 2 is set in advance on the processing target transport unit 2. For example, as shown in FIG. 3, there may be a positional deviation or inclination with respect to the position 21 (target processing target installation position). FIG. 3 is an explanatory diagram for explaining an installation state of the processing target 1 when a displacement or inclination occurs in the installation position of the processing target 1. When such a position shift or tilt occurs when the processing target 1 is installed, a position shift or tilt also occurs in the laser processing position on the processing target 1 with respect to the laser processing position on the processing target 1 set in advance.

  In the electrode paste printing process after the laser opening 13 is formed, the electrode paste needs to be printed on the laser opening 13. When a position shift in the pitch direction of laser processing or an inclination of laser processing occurs, a region where the laser opening 13 does not exist is generated below the electrode paste. For this reason, sufficient conduction cannot be obtained, and the characteristics of the polycrystalline silicon solar cell deteriorate.

  In the formation of the narrow contact on the back surface of the polycrystalline silicon solar cell in the present embodiment, the width of the laser opening 13 is 40 μm. The region where the effect of the narrow contact structure is obtained is a region other than the portion where the electrode is formed. For this reason, in order to maximize the effect of the narrow contact structure, it is preferable that the width of the electrode paste to be printed is the same as the width of the laser opening 13 or at most several times larger. As described above, in order to perform laser processing so that the laser opening 13 is surely present below the electrode paste, the processing position accuracy is required to be within several tens of μm.

  The polygon mirror 7 can scan the laser beam B at a constant speed and at a high speed. By combining the conveyance of the object 1 to be processed by the object to be processed 2 at a constant speed and the scanning of the laser beam B by the polygon mirror 7. It is possible to process the same pattern at high speed. However, the timing of laser beam scanning cannot be accurately changed in accordance with the positional deviation of the workpiece 1.

  Conventionally, in the processing that requires the accuracy of the processing position on the processing object 1 as described above, after the processing object 1 is installed on the processing object conveying means 2, the position of the processing object 1 is detected, and the detection is performed. It is necessary to adjust the position of the processing target 1 based on the signal or to change the transport speed of the processing target transport means 2 and the laser beam scanning direction of the polygon mirror 7. However, since these operations take time, processing time other than laser processing increases, and as a result, a sufficient processing speed cannot be obtained. Therefore, laser processing cannot be performed at high speed with high processing position accuracy.

  The laser processing apparatus according to the present embodiment has high processing position accuracy even in a process in which the processing target transport unit 2 transports the processing target 1 at a constant speed and the polygon mirror 7 scans the laser beam B. In addition, it is possible to perform laser processing at high speed. That is, the laser processing apparatus according to the present embodiment detects the position of the processing target 1 on the processing target transporting means 2 at two points, and the positional deviation of the processing target 1 actually arranged based on the detection result. And information on tilt can be obtained. Then, by controlling the deflection direction of the laser beam B by the galvanometer mirror 6 based on the information on the positional deviation and inclination of the processing target 1 and the information on the transport position of the processing target 1 by the processing target transport means 2, the laser beam is controlled. The machining position by B is corrected to prevent the machining position from being displaced due to the installation position of the machining object 1 and the inclination of the machining position, and laser machining can be performed at high speed with high machining position accuracy.

  Hereinafter, a method for performing laser processing with high processing position accuracy and high speed by using the galvanometer mirror 6 in the laser processing apparatus according to the present embodiment will be specifically described.

  First, a description will be given of the locus of laser processing on the processing target 1 when the galvano mirror 6 is not provided and the processing target 1 is installed on the processing target transporting unit 2 according to the target and transported at a constant speed.

  The scanning speed of the laser beam by the polygon mirror 7 is 5,326 mm / second, the number of scanning times of the laser beam is 25 times / second, and the conveying speed of the processing object conveying means 2 is 100 mm / s. At this time, as shown in FIG. 4, linear laser processing with an interval of 4 mm is performed obliquely on the processing object 1. That is, the laser processing locus 31 is a direction inclined from a direction perpendicular to or parallel to each side of the processing object 1. FIG. 4 is a schematic diagram for explaining a laser processing locus on a processing target 1 in which a conventional galvanometer mirror 6 is installed at a target position by an unused laser processing apparatus. In this figure, for convenience of explanation, the laser processing pattern is indicated by a dotted line, but the actual laser processing pattern is a continuous pattern without a break.

  Next, in the laser processing apparatus according to the present embodiment, the locus of laser processing when the processing target 1 is installed on the processing target transport unit 2 as intended and transported at a constant speed will be described. The laser beam scanning speed by the polygon mirror 7 is 5,326 mm / second, the number of times of laser beam scanning is 25 times / second, and the transport speed of the processing object transport means 2 is 100 mm / s, as in the case without the galvanometer mirror 6. .

  In the laser processing apparatus according to the present embodiment, the control unit 8 controls the galvanometer mirror 6 based on the position signal related to the position of the processing target transport unit 2 and the timing signal of the laser beam scanning by the polygon mirror 7, and the laser beam By adjusting the deflection direction of B in a direction parallel to the conveyance direction of the workpiece 1, the laser machining locus 31 becomes a direction perpendicular to or parallel to each side of the workpiece 1 as shown in FIG. Is possible. FIG. 5 is an explanatory diagram of a locus of laser processing on the processing target 1 installed at a target position by the laser processing apparatus according to the present embodiment using the galvano mirror 6. In FIG. 5, as in FIG. 4, the laser processing pattern is indicated by a dotted line for convenience of explanation, but the actual laser processing pattern is a continuous pattern without a break.

  FIG. 6 shows the laser beam deflection position by the galvanometer mirror 6 at this time. FIG. 6 is a characteristic diagram showing a laser beam deflection position by the galvano mirror 6 when the processing target 1 installed at the target position is processed by the laser processing apparatus according to the present embodiment. The horizontal axis in the figure represents time. Further, the vertical axis in the figure represents the laser beam deflection position by the galvanometer mirror 6, and the + direction of the laser beam deflection position on the vertical axis is the direction of the conveyance speed by the processing object conveyance means 2. The laser beam deflection position is a periodic function with a period of 40 ms which is the scanning period of the polygon mirror 7 and an amplitude of 2.86 mm. The inclination of the positive inclination portion is the conveyance speed of the processing object conveyance means 2. In accordance with 100 mm / s, the relative movement of the laser beam B in the transport direction on the workpiece 1 is canceled.

  The amplitude W at this time can be calculated as follows. W = L ÷ Vb × Vt, where L is the size perpendicular to the conveyance direction of the workpiece 1, Vb is the laser beam scanning speed of the polygon mirror 7, and Vt is the conveyance speed of the workpiece conveyance means 2. Since L = 150 mm, Vb = 5236 mm / s, and Vt = 100 mm / s, W = 2.86 mm.

  Next, as an example, a case will be described in which the processing target 1 is installed with an inclination of 1 ° (0.17 rad) in the transport direction with the center of the processing target 1 as the rotation center as shown in FIG. FIG. 7 is an explanatory diagram for explaining an installation state of a processing target when an inclination occurs in the installation position of the processing target 1. Since the polygon mirror 7 and the processing target transport unit 2 operate at a constant speed, the polygon mirror 7 and the processing target transport unit 2 operate in the same manner as when the processing target 1 is installed as intended.

  FIG. 8 shows the laser beam deflection position by the galvanometer mirror 6 when the workpiece 1 is installed at an angle. FIG. 8 is a characteristic diagram showing a laser beam deflection position by the galvano mirror 6 when processing the workpiece 1 tilted by the laser processing apparatus according to the present embodiment. In this case, in order to correct the 1 ° inclination of the object 1 to be processed, the laser beam deflection position by the galvanometer mirror 6 has an amplitude of 5.48 mm, and the inclination of the positive inclination portion is 191.4 mm / s.

  The amplitude Wl at this time is Wl = L ÷ Vb × Vt + L × sin (Al) where the inclination of the workpiece 1 is Al, L = 150 mm, Vb = 5236 mm / s, Vt = 100 mm / s, Al = Since 1 °, Wl = 5.48 mm. Since the range of the laser beam deflection position is Wl / W = 1.914 times as compared with the case where the processing target 1 is installed according to the target, the inclination of the positive portion is 100 × 1.914 = 191. 4 mm / s. By controlling the galvanometer mirror 6 under such conditions, laser processing is possible in which the laser processing locus 31 is perpendicular to or parallel to each side of the processing object 1 as shown in FIG.

  In this way, the range of the deflection position of the laser beam B by the galvanometer mirror 6 is expanded, and the speed during the laser beam deflection operation is changed, so that the processing object 1 installed at an inclination is also shown in FIG. In addition, laser processing is possible in which the locus 31 of laser processing is in a direction perpendicular to or parallel to each side of the processing target 1. Further, the scanning speed of the laser beam B by the polygon mirror 7 is maintained as it is, and the scanning range of the laser beam B is expanded and changed, so that the polygon mirror 7 is installed inclined from the direction perpendicular to the conveying direction as shown in FIG. The machining position can be corrected even with respect to the machining target 1 installed in a tilted position, and the laser machining locus 31 is perpendicular or parallel to each side of the machining target 1 as shown in FIG. Laser processing in the direction is possible. FIG. 9 is a schematic diagram for explaining an installation state of the processing target 1 that can be laser processed by the same laser beam deflection by the laser processing apparatus according to the present embodiment.

  Next, as shown in FIG. 10, a case will be described in which the workpiece 1 is installed with a 0.5 mm position shift in a direction parallel to the transport direction. FIG. 10 is a schematic diagram for explaining an installation state of the processing target 1 installed with a positional shift in a direction parallel to the transport direction. Since the polygon mirror 7 and the processing target transport unit 2 operate at a constant speed, the polygon mirror 7 and the processing target transport unit 2 operate in the same manner as when the processing target 1 is installed as intended.

  FIG. 11 shows the laser beam deflection position by the galvano mirror 6 when the workpiece 1 is installed at a position shifted by 0.5 mm in a direction parallel to the transport direction. FIG. 11 is a characteristic diagram showing a laser beam deflection position by the galvanometer mirror 6 when processing the processing target 1 installed in a direction parallel to the transport direction by the laser processing apparatus according to the present embodiment. is there.

  As shown in FIG. 11, the laser beam deflection position by the galvano mirror 6 when the processing target 1 is installed with a 0.5 mm position shift in the direction parallel to the transport direction is the processing target as shown in FIG. 6. The laser beam deflection position when 1 is installed is shifted by 0.5 mm. By controlling the galvanometer mirror 6 under such conditions, laser processing is possible in which the laser processing locus 31 is perpendicular to or parallel to each side of the processing object 1 as shown in FIG.

  As described above, in the laser processing apparatus according to the present embodiment, the position of the processing object 1 is controlled by controlling the driving method of the galvanometer mirror 6 even when the processing object 1 is displaced in the direction parallel to the transport direction or tilted. The influence of the deviation or inclination on the laser processing position can be corrected, and laser processing is possible in which the laser processing locus 31 is perpendicular to or parallel to each side of the processing object 1 as shown in FIG. When laser processing is performed on the processing object 1 in a straight line at equal intervals, even if the processing object 1 is displaced in a direction perpendicular to the conveyance direction, it can be dealt with by scanning control using the polygon mirror 7 and there is no problem. Therefore, it is not necessary to correct by driving the galvanometer mirror 6.

  Next, a method for detecting a positional deviation or inclination in a direction parallel to the conveyance direction of the workpiece 1 will be described. The position detection means 3 installed at two points on the processing object conveying means 2 detects the position of the processing object 1 that is actually arranged, and information on the detected position of the processing object 1 is sent to the control means 8. . It has information (setting position information) related to the installation position of the processing target 1 on the processing target transport unit 2 set in advance, and the control unit 8 detects the detection result of the position detection unit 3 and the preset processing. Based on the information (setting position information) regarding the installation position of the processing target 1 on the target transporting means 2, it is possible to detect a positional deviation or inclination in a direction parallel to the transport direction of the processing target 1. For example, as the position detection means 3 of the processing target 1, the position of the processing target 1 actually arranged is detected by detecting the end face of the processing target 1 using an image recognition device composed of a microscope and a CCD camera. it can. A method of detecting using an alignment mark is also conceivable.

  By using the laser processing apparatus according to the present embodiment as described above, the laser openings 13 having a width of 40 μm and an interval of 4 mm are efficiently formed on the insulating film 12 formed on the back surface of the polycrystalline silicon solar cell with high processing position. Can be obtained. Then, for example, the electrode width is set to about 100 μm, and electrode paste is printed on the laser opening 13 and fired, whereby a narrow contact can be formed on the back surface of the polycrystalline silicon solar cell.

  Narrow contacts were actually formed by the method using the laser processing apparatus according to the present embodiment described above. As a result, the laser opening 13 on the insulating film 12 did not protrude from the printed electrode paste, and it was confirmed that a narrow contact having good conduction characteristics with low contact resistance was formed.

  As described above, according to the laser processing apparatus of this embodiment, the deflection of the laser beam B in the direction parallel to the transport direction of the processing target 1 based on the position of the processing target 1 on the processing target transport means 2. The direction can be adjusted, and even when a positional deviation or inclination occurs with respect to the preset installation position 21 of the processing target 1 on the processing target conveying means 2, the influence of the positional deviation or inclination is corrected. Thus, it is possible to perform laser processing on the processing target 1 with high processing position accuracy and at high speed.

  As described above, the laser processing apparatus according to the present invention is useful for laser processing in the case where a displacement or inclination occurs with respect to a preset installation position.

It is a schematic diagram for demonstrating schematic structure of the laser processing apparatus concerning embodiment of this invention. It is a schematic diagram for demonstrating the formation process of the narrow contact of a polycrystalline silicon solar cell. It is a schematic diagram for demonstrating the formation process of the narrow contact of a polycrystalline silicon solar cell. It is a schematic diagram for demonstrating the formation process of the narrow contact of a polycrystalline silicon solar cell. It is explanatory drawing for demonstrating the installation condition of the process target when position shift and inclination arise in the installation position of the process target. It is a schematic diagram for demonstrating the locus | trajectory of the laser processing on the process target installed in the target position by the laser processing apparatus which has not used the conventional galvanometer mirror. It is explanatory drawing of the locus | trajectory of the laser processing on the process target installed in the target position by the laser processing apparatus concerning this Embodiment using a galvanometer mirror. It is a characteristic view which shows the laser beam deflection | deviation position by a galvanometer mirror in the case of processing the process target installed in the target position with the laser processing apparatus concerning this Embodiment. It is explanatory drawing for demonstrating the installation condition of the process target when inclination arises in the installation position of a process target. It is a characteristic view which shows the laser beam deflection | deviation position by a galvanometer mirror in the case of processing the process target installed incline by the laser processing apparatus concerning this Embodiment. It is a schematic diagram for demonstrating the installation condition of the process target which can be laser-processed by the same laser beam deflection with the laser processing apparatus concerning this Embodiment. It is a schematic diagram for demonstrating the installation condition of the process target installed in position shifted in the direction parallel to a conveyance direction. It is a characteristic view which shows the laser beam deflection | deviation position by a galvanometer mirror in the case of processing the process target installed in the direction parallel to a conveyance direction by the laser processing apparatus concerning this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing object 2 Processing object conveyance means 3 Position detection means 4 Laser oscillator 5 Laser beam shaping means 6 Deflection means (galvano mirror)
7 Scanning means (polygon mirror)
8 Control means 9 Condensing means (Fθ lens)
DESCRIPTION OF SYMBOLS 11 Polycrystalline silicon substrate 12 Insulating film 13 Laser opening part 14 Narrow contact 21 The installation position of the process target on the preset process target conveyance means (target process target installation position)
22 Installation position of processing target on actual processing target conveying means 31 Laser processing locus B Laser beam

Claims (4)

A processing target transporting means for holding the processing target with the processing surface facing up and transporting the processing target at a constant speed in the first direction;
Position detecting means for detecting the position of the processing object on the processing object conveying means;
A laser oscillator that outputs a laser beam;
Deflecting means for deflecting the laser beam by adjusting a deflection direction of the laser beam output from the laser oscillator in a direction parallel to the first direction;
Scanning means for deflecting the laser beam deflected by the deflection means to scan the processing surface at a constant speed in a predetermined scanning direction;
The laser beam in the deflection unit based on the detection result of the position of the processing target on the processing target transport unit detected by the position detection unit and information on the transport position of the processing target by the processing target transport unit Control means for controlling the deflection direction of
Condensing means for condensing the laser beam deflected by the deflecting means and the scanning means on the work surface;
Providing
A laser processing apparatus characterized by the above. The control means controls the deflection position of the laser beam in the deflection means based on position information;
The laser processing apparatus according to claim 1. The scanning unit scans the laser beam in a second direction substantially orthogonal to the first direction on the processing surface;
The laser processing apparatus according to claim 1. The processing pattern by the laser beam with respect to the processing surface is a pattern in which a plurality of substantially linear patterns are provided at substantially equal intervals,
The laser processing apparatus according to claim 1.

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