JP5202026B2 - Laser scribing equipment - Google Patents

Description

  The present invention relates to a laser scribing apparatus, and more particularly to a laser scribing apparatus that forms a pattern of solar cells provided in a solar cell substrate.

  For the manufacture of a thin film solar cell, a laser scribing device that forms a pattern of a thin film solar cell by irradiating a desired portion of a workpiece by irradiating a laser beam is used.

  In the laser scribing apparatus described in Patent Document 1, a measurement laser oscillator for measuring the dimensions of a machining shape is provided on the side opposite to the machining laser oscillator provided on the laser machining surface side of the workpiece. In this invention, a machining shape (through hole) is formed in the workpiece by irradiating the processing laser beam with a pulse, and the amount of the laser beam from the measurement laser oscillator that has passed through the through hole is determined for each pulse described above. taking measurement. Then, the processing laser is stopped when the measured light quantity reaches a predetermined light quantity. Thus, the diameter of the through hole is not controlled by the laser energy, but is controlled by the number of times of laser light irradiation.

  In the laser scribing device described in Patent Document 2, a reverse bias is applied to the thin-film solar cell after the reflective electrode layer is formed, and the leaked portion is detected by detecting infrared rays radiated from the portion heated by the leak from the surface to be measured. Determine. And after recording the two-dimensional coordinate corresponding to a leak location, a laser beam is irradiated to a leak location and a defect location is repaired. Thus, the defective portion of the photovoltaic element is detected, the defective portion is mapped, and the defect is repaired.

  Also in the laser scribing method described in Patent Document 3, a reverse bias is applied to the thin-film solar cell, and infrared rays radiated from a location that generates heat due to leakage are detected to determine the leak location.

JP 58-006785 A Japanese Patent No. 3098950 JP 2002-203978 A

  However, in the invention described in Patent Document 1, only the inspection based on the difference in the amount of light of the measurement laser beam is performed. Therefore, when there is a minute residue that cannot be confirmed only by the difference in the amount of laser light, there is a problem that the defect inspection cannot be performed accurately.

  Moreover, in the invention described in Patent Document 2, since it is necessary to incorporate defect inspection into a process different from laser scribing, the manufacturing process becomes long. In addition, when the manufacturing process is lengthened, there is a problem that a defect is further generated during the defect repairing process because the possibility that foreign matter adheres to the thin film solar cell increases. Further, in the defect repair, when foreign matter is attached to the defective portion, there is a problem that the defective portion cannot be repaired even if the laser beam for laser scribing is irradiated again on the defective portion.

  In the inventions described in Patent Document 2 and Patent Document 3, a reverse bias is applied to the thin-film solar cell, and infrared rays radiated from a location that generates heat due to leakage are detected. However, when the defect is very small, heat is not generated sufficiently to detect infrared rays even when a reverse bias voltage is applied to the defective portion, and thus there is a problem that the defect inspection cannot be performed accurately.

  The present invention has been made to solve the above-described problems. At the same time as laser scribing, defect inspection is accurately performed, and defect repair is ensured even if foreign matter adheres to the defective part. It is an object of the present invention to provide a possible laser scribing apparatus.

The laser scribing apparatus according to the present invention forms a groove-like pattern in which the semiconductor light conversion layer and the electrode layer are removed by laser scribing processing on the semiconductor light conversion layer and the electrode layer laminated on the transparent insulating substrate, A laser scribing apparatus for forming a plurality of solar cells, comprising laser irradiation means for irradiating laser light used for the laser scribing process from the transparent insulating substrate side . And a shape inspection means for detecting the laser light that has passed through the pattern to determine the presence or absence of a defect in the pattern, a light source for irradiating visible light to a single solar cell formed by the pattern, Measure the diode characteristics of the single solar cell while irradiating it with visible light, and check whether there is a short leak defect based on the comparison between the measurement result and the diode characteristics of a normal solar cell set in advance. Electrical characteristic inspection means for determining The foreign matter removing means for removing foreign matter from the electrode layer side from the defective portion of the pattern of the solar battery cell determined to be defective by the shape inspection means and the electrical characteristic inspection means, and the foreign matter removing means Repairing means for repairing a defective portion of the pattern from which the foreign matter has been removed from the transparent insulating substrate side .

  In the laser scribing apparatus of the present invention, since it can be performed simultaneously with laser scribing and defect inspection, it is possible to prevent a decrease in throughput. Further, in the defect inspection, since the electrical characteristic inspection is performed in addition to the shape inspection, the defect inspection can be accurately performed. Further, when foreign matter is attached to the defective portion, the defect is repaired after the foreign matter is removed, so that the defect can be reliably repaired.

<Embodiment 1>
Solar cells capable of directly converting sunlight into electrical energy have been attracting attention as a clean electrical energy production device that is friendly to the global environment because of the small amount of CO ₂ emissions associated with the conversion. Yes. Currently, crystalline Si solar cells using a crystalline silicon (crystalline Si) substrate as a semiconductor light conversion layer are mainly supplied. However, the shortage of crystalline Si substrate supply affects the production and price of solar cells. It has become.

  Therefore, a thin film solar cell using amorphous silicon as a semiconductor light conversion layer has been developed as a solar cell that can be manufactured without being affected by the supply situation of the crystalline Si substrate and can be reduced in cost. As the amorphous silicon, for example, amorphous silicon (a-Si) or microcrystalline silicon (μc-Si) is used for the semiconductor light conversion layer. Thin-film solar cells include a single cell type composed of one type of semiconductor light conversion layer and a plurality of types of cells each having a different light absorption wavelength called another junction type or tandem type.

  FIG. 1 is a cross-sectional view showing a single cell thin film solar cell. Hereinafter, the thin film solar cell is referred to as a thin film solar cell module. A thin film solar cell module 1 according to FIG. 1 includes a thin film solar cell substrate 2, a protective film 8, an extraction electrode 9, and a lead wire 10. The extraction electrode 9 is formed on the transparent conductive film 5 at the end of the thin film solar cell substrate 2, and the lead wire 10 is formed in connection with the extraction electrode 9. The protective film 8 is a film that prevents power generation performance deterioration caused by breakage or moisture, and is formed at the end of the manufacturing process of the thin-film solar cell module 1.

  FIG. 2 is a perspective view showing the thin film solar cell substrate 2. The thin film solar cell substrate 2 includes a transparent insulating substrate 3 and thin film solar cells 4 formed on the surface of the transparent insulating substrate 3. The thin-film solar battery 4 includes a transparent conductive film 5, a semiconductor light conversion layer 6, and a reflective electrode layer 7 that are sequentially stacked on the surface of the transparent insulating substrate 3. For the semiconductor light conversion layer 6, for example, the above-described a-Si or μc-Si is used. A groove-like pattern 11 reaching the transparent conductive film 5 is formed in the semiconductor light conversion layer 6 and the reflective electrode layer 7. The pattern 11 of the thin-film solar battery cell 4 according to the present embodiment is a line pattern shown in FIG. Thus, by forming the pattern 11 of the thin-film solar battery cell 4, a plurality of thin-film solar battery cells 4 are electrically connected in series.

  As a method for forming the pattern 11 of the thin-film solar battery cell 4 on the semiconductor light conversion layer 6 and the reflective electrode layer 7, there are a dynamic polishing method, a chemical etching method, and a laser irradiation method. Among them, laser scribing that irradiates a laser is generally used for pattern formation. Laser scribing is a method in which the semiconductor light conversion layer 6 is irradiated with laser light, the light energy is absorbed by the semiconductor light conversion layer 6 and converted into thermal energy, and the semiconductor light conversion layer 6 and the reflective electrode layer 7 are scattered.

  FIG. 10 is a schematic side view showing a configuration of a laser scribing apparatus that is a premise of the laser scribing apparatus according to the present invention, among laser scribing apparatuses that perform laser scribing. The laser scribing apparatus according to FIG. 10 includes a first laser oscillator 12, a reflection mirror 13, a condenser lens 14, and a stage 15. The operation | movement which forms the pattern 11 of the thin film photovoltaic cell 4 by laser scribing process is demonstrated using this figure.

  First, a thin film solar cell substrate 2 in which a transparent conductive film 5 patterned in advance is formed on a transparent insulating substrate 3 and a semiconductor light conversion layer 6 and a reflective electrode layer 7 are sequentially laminated thereon is prepared. This thin film solar cell The substrate 2 is set on the stage 15. In the laser scribing apparatus according to FIG. 10, the thin film solar cell substrate 2 is irradiated from the transparent insulating substrate 3 side with the first laser beam 16 irradiated with pulses from the first laser oscillator 12 via the reflection mirror 13 and the condenser lens 14. Irradiate. In synchronization with the pulse, the stage 15 is stepped in one direction. Then, the above pulse irradiation and step movement are repeated.

  FIG. 11 is a plan view showing the irradiation position of the first laser beam 16. In FIG. 11, the beam shape (laser beam shape) 28 of the first laser beam 16, the area 29 where the laser beam shape 28 overlaps, the first laser beam center that is the center of the beam of the first laser beam 16. 30, a stage feed width 31, and a stage moving direction 32 are shown. As shown in FIG. 11, since the first laser beam 16 is focused on the first laser beam center 30, the laser beam shape 28 is circular.

  The stage feed width 31 is made smaller than the diameter of the laser beam shape 28. With this stage feed width 31, the stage 15 is moved in the stage moving direction 32 in synchronization with the pulse of the first laser beam 16. In FIG. 11, the laser light shapes 28-1 to 28-3 after movement are shown with reference numerals in order from the closest to the present. When the stage 15 is moved in this way, the laser beam shape 28 and the laser beam shape 28-1 overlap in the area 29. Therefore, in the area 29, the first laser light 16 is irradiated in an overlapping manner. Similarly, the other areas 29 are irradiated with the first laser beam 16 in an overlapping manner.

  The portion of the semiconductor light conversion layer 6 irradiated with the first laser light 16 absorbs the first laser light 16 and evaporates, and then scatters together with the reflective electrode layer 7. Thus, the part surrounded by the broken line in FIG. 10 is scattered. FIG. 12 is an enlarged plan view of the portion A in FIG. 2, that is, the line-shaped pattern 11 (contact line) after the laser scribing process. As shown in FIG. 11, the laser scribing apparatus according to FIG. 10 irradiates the first laser beam 16 while moving the thin film solar cell substrate 2 in the stage moving direction 32 by the stage 15. Therefore, the pattern 11 of the thin-film solar battery cell 4 formed on the semiconductor light conversion layer 6 and the reflective electrode layer 7 is a line pattern in which arcs are connected as shown in FIG. The pattern 11 has a protrusion 33 at a portion where the arc is connected. By the above, the semiconductor light conversion layer 6 and the reflective electrode layer 7 are divided, and the thin film solar cell substrate 2 in which the plurality of thin film solar cells 4 are connected in series can be obtained.

  Next, a case where foreign matter has adhered on the reflective electrode layer 7 during laser scribe processing will be described. FIG. 13 is a schematic side view showing a state of laser scribing when a foreign material 17 is temporarily attached on the reflective electrode layer 7. As shown in this figure, when the foreign matter 17 adheres to the reflective electrode layer 7 at the site to be laser scribed, the foreign matter 17 prevents the transpiration of the semiconductor light conversion layer 6 that has absorbed the first laser light 16. Therefore, it cannot be scattered sufficiently.

  As a result, the semiconductor light conversion layer 6 and the reflective electrode layer 7 remain at the place where the foreign matter 17 is adhered, and a defect of the pattern 11 occurs. If the adjacent thin film solar cells 4 are connected to each other by this pattern defect, it causes power generation failure due to a short circuit or leakage during power generation. In order to repair this defect, it is assumed that the laser scribing process is performed again. However, if the foreign matter 17 remains attached, it is still impossible to perform a good laser scribing process.

  Therefore, the present invention provides a laser scribing apparatus capable of accurately detecting a defect portion of the pattern 11 of the thin-film solar battery cell 4 that can be a short circuit or a leak path at the same time as the above-described laser scribing and reliably repairing the defect. The purpose is to obtain. Hereinafter, the laser scribing apparatus according to the present embodiment will be described.

  FIG. 3 is a schematic side view showing the configuration of the laser scribing apparatus according to the present embodiment. The laser scribing apparatus according to the present embodiment forms the pattern 11 of the thin-film solar battery cell 4 that is a solar battery cell included in the thin-film solar battery substrate 2 that is a solar battery substrate by laser scribing. The laser scribing apparatus according to the present embodiment can be applied to either a single cell type or a tandem type as long as it is a thin film solar cell module 1, but here, as an example, a single cell type thin film solar cell module 1 is used. The case of forming will be described. As shown in FIG. 3, the laser scribing apparatus according to the present embodiment includes a first laser oscillator 12, a reflection mirror 13, a condenser lens 14, a stage 15, a laser light detector 18, and a defect position. A storage system 19, a second laser oscillator 20, an electrical property measuring instrument 23, a probe 24, a light source 25, a cover 26, and a stage position control system 27 are provided.

  The laser scribing apparatus according to the present embodiment includes a first laser oscillator 12 that is a laser irradiation unit. The first laser oscillator 12 irradiates a first laser beam 16 that is a laser beam used for laser scribing. The first laser light 16 from the first laser oscillator 12 is pulsed to the thin-film solar cell substrate 2 from the transparent insulating substrate 3 side via the reflection mirror 13 and the condenser lens 14. Thus, the first laser light 16 irradiated on the thin film solar cell substrate 2 from the transparent insulating substrate 3 side passes through the transparent insulating substrate 3 and the transparent conductive film 5 and is absorbed by a part of the semiconductor light conversion layer 6. , Converted into thermal energy. Due to the thermal energy, the temperature of the semiconductor light conversion layer 6 at the site where the first laser beam 16 is absorbed rises. When the temperature reaches the boiling point, the semiconductor light conversion layer 6 at that portion evaporates. When the semiconductor light conversion layer 6 evaporates, the reflective electrode layer 7 also scatters simultaneously.

  In parallel with this, the stage 15 is moved stepwise in one direction in synchronization with the pulse of the first laser oscillator 12. By repeating this pulse irradiation and step movement, the pattern of the thin-film solar battery cell 4 is formed. The pattern according to the present embodiment is a line-shaped pattern 11 according to FIG.

  The laser scribing apparatus according to the present embodiment includes a laser light detector 18 which is shape inspection means. The laser light detector 18 detects the first laser light 16 that has passed through the pattern 11 of the thin-film solar battery cell 4, and determines the presence or absence of a pattern defect. In the present embodiment, the laser light detector 18 is installed on the side facing the first laser oscillator 12 with the thin film solar cell substrate 2 interposed therebetween. When the semiconductor light conversion layer 6 and the reflective electrode layer 7 are scattered by the laser scribe process described above, the first laser light 16 passes through the pattern 11 of the thin-film solar battery cell 4.

  If the foreign matter 17 is attached on the reflective electrode layer 7, the evaporation of the semiconductor light conversion layer 6 is hindered by the foreign matter 17, so that the portion of the semiconductor light conversion layer 6 where the foreign matter 17 is attached is reflected. The electrode layer 7 remains. Here, as a state where the semiconductor light conversion layer 6 and the reflective electrode layer 7 remain, a state where the reflective electrode layer 7 is scattered but a part of the semiconductor light conversion layer 6 remains, and the semiconductor light conversion layer 6 and the reflective electrode layer 7 remain. There is a state that both of remain.

  In the state where only the former semiconductor light conversion layer 6 remains, the first laser light 16 is partially absorbed by the semiconductor light conversion layer 6, but most of the first laser light 16 passes through the semiconductor light conversion layer 6. Therefore, when the foreign material 17 adheres on the reflective electrode layer 7 and a defect occurs in the semiconductor light conversion layer 6 in the pattern 11, the amount of received light detected by the laser light detector 18 does not occur. And almost the same.

  On the other hand, in the state where both of the latter semiconductor light conversion layer 6 and the reflective electrode layer 7 remain, the first laser light 16 is reflected by the reflective electrode layer 7, and therefore a part of the optical path of the first laser light 16. Alternatively, the entire optical path is shielded. Therefore, the first laser beam 16 cannot pass through the pattern 11 of the thin-film solar battery cell 4 and cannot pass through the thin-film solar battery substrate 2. Therefore, when the foreign material 17 adheres on the reflective electrode layer 7 and a defect occurs in the reflective electrode layer 7 in the pattern 11, the amount of received light detected by the laser light detector 18 is when the defect does not occur. Compared to decrease.

  Therefore, the laser light detector 18 according to the present embodiment detects the amount of received light of the first laser light 16 that has passed through the pattern 11, and compares the amount of received light with a preset reference value. By this comparison, it is determined whether or not the normal pattern 11 is formed on the thin-film solar battery cell 4. In the present embodiment, when it is determined that the amount of received light does not reach the specified value, the laser light detector 18 determines that the laser scribing process is not performed normally and the pattern 11 has a defect. When the first laser beam 16 cannot be detected by the laser beam detector 18, the two-dimensional coordinates corresponding to the position of the stage 15 at that time are stored in a defect position storage system 19 described later.

  The laser scribing apparatus according to the present embodiment includes an electrical property measuring instrument 23 that is electrical property inspection means. The electrical property measuring instrument 23 measures the diode characteristics of the thin-film solar battery cell 4 to determine whether there is a short leak defect. When the semiconductor light conversion layer 6 and the reflective electrode layer 7 are divided by the laser scribing process described above, the transparent conductive film 5 and the reflective electrode layer 7 are electrically sandwiched between the semiconductor light conversion layer 6 as shown in FIG. Thus, the thin film solar cells 4 connected to each other are formed. The light source 25 irradiates the thin-film solar battery cell 4 with visible light. The cover 26 is provided so as not to leak visible light from the light source 25 to the outside. In parallel, the extraction electrode 9 connected to the transparent conductive film 5 of the thin-film solar cell 4 and the electrical property measuring instrument 23 are connected by a probe 24, and the reflective electrode layer 7 of the thin-film solar cell 4 and the electrical property measuring instrument are connected. 23 is connected with the probe 24.

  Thus, when the thin-film solar battery 4 is irradiated with visible light from the light source 25, the semiconductor light conversion layer 6 absorbs visible light and generates power, and a current flows from the transparent conductive film 5 to the reflective electrode layer 7. The electrical characteristic measuring instrument 23 measures the diode characteristic of the thin-film solar battery cell 4 through the probe 24 and compares it with the normal diode characteristic. Then, the electrical property measuring instrument 23 determines whether there is a short leak defect due to the defect of the pattern 11 based on the comparison. FIG. 4 is a diagram showing diode characteristics of a normal thin-film solar battery cell 4 having no pattern defect. FIG. 5 is a diagram showing the diode characteristics of the thin-film solar battery cell 4 having a pattern defect and having a leak path. The electrical characteristic measuring instrument 23 according to the present embodiment determines that there is a leak path when the diode characteristic substantially the same as the diode characteristic shown in FIG. 4 cannot be obtained. Note that the voltage value and current value that define the diode characteristics in FIG. 4 are set in advance according to the characteristics of the thin-film solar battery cell 4.

  The laser scribing apparatus according to the present embodiment includes a stage 15 and a defect position storage system 19 which is a storage unit. The stage 15 can transfer the thin-film solar battery substrate 2 including the thin-film solar battery cells 4 in at least a two-dimensional direction. The defect position storage system 19 stores, as two-dimensional coordinate information, two-dimensional coordinates corresponding to the position of the stage 15 when it is determined by the laser light detector 18 and the electrical property measuring instrument 23 that there is a defect. The laser scribing apparatus according to the present embodiment stores two-dimensional coordinate information in the defect position storage system 19 when it is determined that there is a defect in each of the laser light detector 18 and the electrical property measuring instrument 23, and all After the laser scribing process is completed, the information is compared and analyzed.

  Here, it can be predicted that there is a patterning defect in the reflective electrode layer 7 that reflects the first laser light at a location where both the laser light detector 18 and the electrical property measuring instrument 23 are determined to be defective. Further, a patterning defect of the semiconductor light conversion layer 6 that transmits the first laser light is located at a position where the laser light detector 18 determines that there is no defect and the electric characteristic measuring device 23 determines that there is a defect. Can be predicted. As described above, even when there is a short leak due to a minute patterning defect that cannot be determined only by the laser light detector 18, it can be determined by the electrical characteristic measuring device 23. That is, it is possible to perform defect inspection with higher sensitivity than defect inspection using only the laser light detector 18. In addition, it can be determined that defect repair is not necessary at a location where the laser light detector 18 determines that there is a defect and the electrical property measuring instrument 23 determines that there is no defect. Thereby, unnecessary repair work can be reduced and throughput can be improved.

  The stage position control system 27 moves the stage 15 to a position corresponding to the two-dimensional coordinates determined to have a patterning defect in the semiconductor light conversion layer 6 or the reflective electrode layer 7 based on the above analysis result. Thus, the laser scribing apparatus according to the present embodiment controls the movement of the stage 15 based on the two-dimensional coordinate information stored in the defect position storage system 19.

  The laser scribing apparatus according to the present embodiment includes a foreign matter removing unit. The foreign matter removing means according to the present embodiment includes a reflection mirror 13, a condensing lens 14, a second laser oscillator 20 provided on the opposite side of the first laser oscillator 12 across the thin film solar cell substrate 2. Is provided. After the movement of the stage 15 described above, the foreign matter removing means is not easily absorbed by the transparent insulating substrate 3, the transparent conductive film 5, the semiconductor light conversion layer 6, and the reflective electrode layer 7, and removes the foreign matter 17 on the reflective electrode layer 7. A second laser beam 21 having a removable wavelength is emitted from the second laser oscillator 20. In this way, the above foreign matter removing means is a second laser that is a laser beam for removing foreign matter from the reflective electrode layer 7 side of the thin film solar cell substrate 2 via the reflecting mirror 13 and the condenser lens 14. Irradiate light 21. Thereby, the above-mentioned foreign substance removing means removes the foreign substance 17 from the defective portion of the pattern 11 of the thin-film solar battery cell 4 determined to be defective by the laser light detector 18 and the electrical property measuring instrument 23.

  The laser scribing apparatus according to the present embodiment includes a repair unit. The repairing means according to the present embodiment irradiates the first laser beam 16 used for laser scribing on the defective portion of the pattern 11 of the thin-film solar cell 4 from which the foreign matter 17 has been removed by the foreign matter removing means. 1 laser oscillator 12. With this first laser beam 16, the first laser oscillator 12 repairs the defective portion of the pattern 11 of the thin-film solar cell 4 from which the foreign matter 17 has been removed by the foreign matter removing means described above. This defect repair is based on the analysis result (whether the defect exists in the semiconductor light conversion layer 6 or the reflective electrode layer 7) and the irradiation position and shape of the first laser light 16 according to the size of the defect. May be selectively changed. In this way, highly accurate repair can be performed.

  When the first laser beam 16 irradiated for the purpose of defect repair repairs the pattern defect, the first laser beam 16 passes through the pattern 11 of the thin-film solar battery cell 4. In the laser scribing apparatus according to the present embodiment, the defect repair is completed when the laser beam detector 18 receives the first laser beam 16 that has passed through and the amount of received light reaches the above-mentioned prescribed value. Confirm. When the defect is repaired in this way, the diode characteristics shown in FIG. 4 are obtained.

  According to the laser scribing apparatus according to the present embodiment as described above, since the first laser beam 16 of the first laser oscillator 12 is used for laser scribing and defect detection, laser scribing and defect inspection are performed. Can be done simultaneously. Therefore, it is possible to prevent a decrease in throughput and reduce the possibility that the foreign matter 17 adheres. In the present embodiment, as the defect inspection, a shape inspection by the laser light detector 18 and an electric characteristic inspection by the electric characteristic measuring device 23 are performed. Since this electrical characteristic inspection can detect defects that could not be detected by the shape inspection, the defect inspection can be performed accurately. Furthermore, it can be inspected whether the defect of the pattern 11 of the thin-film solar battery cell 4 is in the semiconductor light conversion layer 6 or the reflective electrode layer 7. In particular, in the processing of the tandem-structured thin-film solar cell module 1 that is expected to be more actively developed for higher efficiency in the future, a cell must be formed by stacking more thin films. Since defect factors are expected to become more complicated, this defect detection is effective. In addition, since the apparatus according to the present embodiment performs defect repair after removing the foreign matter 17 by the above-described foreign matter removing means, the defect can be reliably repaired.

  The laser scribing apparatus according to the present embodiment controls the movement of the stage 15 based on the two-dimensional coordinate information stored in the defect position storage system 19. Therefore, the position of the thin film solar cell substrate 2 can be accurately controlled.

  The laser scribing apparatus according to the present embodiment removes the foreign matter 17 by irradiating the second laser beam 21 for removing the foreign matter from the second laser oscillator 20. Thereby, since the foreign material 17 can be removed using the laser irradiation mechanism in a laser scribing apparatus, the structure of the apparatus can be simplified.

<Embodiment 2>
FIG. 6 is a schematic side view showing the configuration of the laser scribing apparatus according to the present embodiment. In the present embodiment, in addition to the configuration of the first embodiment, a third laser oscillator 34 and a laser beam distance control system 36 are further provided. Hereinafter, among the configurations of the laser scribing apparatus according to the present embodiment, the same configurations as those of the first embodiment are denoted by the same reference numerals, and configurations not newly described are the same as those of the first embodiment. It shall be.

  The first laser oscillator 12 that is the first laser irradiation means according to the present embodiment irradiates the first laser light 16 that is a laser light used for laser scribing. The third laser oscillator 34 that is the second laser irradiation means irradiates the pattern 11 of the thin-film solar battery cell 4 with the third laser light 35 that is a laser beam for inspection. The laser scribing apparatus according to the present embodiment irradiates the thin-film solar cell substrate 2 that is the workpiece from approximately the same direction with the first laser beam 16 and the third laser beam 35.

  The laser light detector 18 that is a shape inspection means detects the third laser light 35 that has passed through the pattern 11 of the thin-film solar battery cell 4 and determines the presence or absence of a pattern defect. The operation of the laser beam detector 18 is the same as that of the laser beam detector 18 described in the first embodiment except that the third laser beam 35 is detected instead of the first laser beam 16.

  The laser beam distance control system 36, which is a control system, converts the distance between the center of the beam of the first laser beam 16 and the center of the third laser beam 35 into a laser scribe process by the first laser oscillator 12. Is controlled so as to be N (N: integer greater than or equal to 2) times the stage feed width 31 which is the machining feed pitch. In the present embodiment, the inter-laser light distance control system 36 controls the angle of the reflection mirror 13 irradiated with the first laser light 16 and the angle of the reflection mirror 13 irradiated with the third laser light 35. To do. By this control, the inter-laser-light distance control system 36 moves the optical paths of the first laser light 16 and the third laser light 35, and the center of the beam of the first laser light 16 and the third laser light. Control the distance between the centers of the 35 beams.

  Hereinafter, the irradiation position relationship between the first laser beam 16 for laser scribing and the third laser beam 35 for shape inspection of the laser scribing apparatus according to the present embodiment will be described. FIG. 7 is an enlarged perspective view of a portion corresponding to portion B in FIG. 6, that is, a portion irradiated with the first laser beam 16 and the third laser beam 35. In FIG. 7, the laminated film 37 including the semiconductor light conversion layer 6 and the reflective electrode layer 7 described above, the third laser light center 38 that is the center of the beam of the third laser light 35, and the first laser light center 30 are illustrated. A distance 39 between laser beams, which is a distance between the first laser beam center 38 and the third laser beam center 38, is shown. Since the third laser beam 35 is focused on the third laser beam center 38, the shape thereof is circular.

  The first laser beam center 30 and the third laser beam center 38 are parallel to the stage movement direction 32, and the third laser beam center 38 is in the stage movement direction more than the first laser beam center 30. It arrange | positions so that it may become 32 front. In order to prevent the first laser beam center 30 and the third laser beam center 38 from overlapping, the inter-laser beam distance control system 36 includes an angle of the reflection mirror 13 to which the first laser beam 16 is irradiated, The angle of the reflection mirror 13 irradiated with the third laser beam 35 is controlled to control the distance 39 between the laser beams to be equal to N times the stage feed width 31. As shown in FIG. 7, the laser beam distance control system 36 according to the present embodiment performs control to make the laser beam distance 39 equal to twice the stage feed width 31. By controlling the irradiation pulse of the first laser oscillator 12 to be equal to the irradiation pulse of the third laser oscillator 34, the third laser light 35 is the same as the first laser light 16 irradiated previously. Irradiation follows the exact same position.

  In the laser scribing apparatus according to the present embodiment, the first laser beam center 30 and the third laser beam center 38 are brought into the positional relationship as described above by the laser beam distance control system 36. For this reason, the third laser beam 35 is prevented from being blocked by the projection 33 of the processing line that is generated when the first laser beam 16 is overlapped and irradiated. Thereby, it can prevent misidentifying the projection part 33 as a defect. In addition, since the first laser beam 16 for laser scribing and the third laser beam 35 for shape inspection are separately used in this way, the intensity of each laser beam is set to an optimum intensity for each application. Can be adjusted. In addition, since the laser scribing process using the first laser beam 16 and the shape inspection using the third laser beam 35 are performed at approximately the same time, it is possible to prevent a decrease in throughput and reduce the possibility of foreign matter 17 adhering. it can. Further, in the present embodiment, as the defect inspection, a shape inspection by the third laser light detector 18 and an electric characteristic inspection by the electric characteristic measuring device 23 are performed. Since this electrical characteristic inspection can detect defects that could not be detected by the shape inspection, the defect inspection can be performed accurately. Furthermore, it can be inspected whether the defect of the pattern 11 of the thin-film solar battery cell 4 is in the semiconductor light conversion layer 6 or the reflective electrode layer 7. In addition, since the apparatus according to the present embodiment performs defect repair after removing the foreign matter 17 by the above-described foreign matter removing means, the defect can be reliably repaired.

  If the diameter of the shape of the third laser beam 35 is made larger than the diameter of the shape of the first laser beam 16, the detection sensitivity of the processing line edge portion where defects are likely to occur can be increased.

  The laser scribing apparatus according to the present embodiment controls the movement of the stage 15 based on the two-dimensional coordinate information stored in the defect position storage system 19. Therefore, the position of the thin film solar cell substrate 2 can be accurately controlled.

<Embodiment 3>
FIG. 8 is a schematic side view showing the configuration of the laser scribing apparatus according to the present embodiment. Unlike the first and second embodiments, the foreign matter removing means included in the laser scribing apparatus according to the present embodiment includes an air knife 40 and an air knife control system 41. Hereinafter, among the configurations of the laser scribing apparatus according to the present embodiment, the same configurations as those of the second embodiment are denoted by the same reference numerals, and configurations not newly described are the same as those of the second embodiment. It shall be.

  In the present embodiment, the above foreign matter removing means blows air, for example, nitrogen air, onto the foreign matter 17 by the air knife 40 installed on the reflective electrode layer 7 side of the thin film solar cell substrate 2. The air knife control system 41 controls ON / OFF of the blowing of nitrogen air from the air knife 40 to the foreign material 17 and the strength of the blowing. And the above-mentioned foreign substance removal means scans the air knife 40 by the air knife control system 41 in the defective location of the pattern 11 of the thin film photovoltaic cell 4 determined to be defective. Then, the air knife control system 41 blows nitrogen air from the air knife 40 to remove the foreign matter 17 by wind pressure.

  According to the laser scribing apparatus according to the present embodiment as described above, the same effect as in the second embodiment can be obtained. Moreover, since the foreign material 17 is removed by the air knife 40, the foreign material 17 can be removed without contact with the thin-film solar cell substrate 2. In addition, if it is set as the structure which blows the nitrogen air which passed the ionizer and improved the dust-proof effect from the air knife 40 to the foreign material 17, charging of the thin film solar cell substrate 2 can also be prevented.

<Embodiment 4>
FIG. 9 is a schematic side view showing the configuration of the laser scribing apparatus according to the present embodiment. The foreign matter removing means included in the laser scribing apparatus according to the present embodiment includes a brush 42 and a brush control system 43. Hereinafter, among the configurations of the laser scribing apparatus according to the present embodiment, the same configurations as those of the second embodiment are denoted by the same reference numerals, and configurations not newly described are the same as those of the second embodiment. It shall be.

  In the present embodiment, the foreign matter removing means presses the brush 42 placed on the reflective electrode layer 7 side of the thin film solar cell substrate 2 with the foreign matter 17. The brush control system 43 controls the pressing strength of the brush 42 against the thin film solar cell substrate 2 and the brush rotation speed. And the above-mentioned foreign material removal means scans the brush 42 by the brush control system 43 in the defect location of the pattern 11 of the thin film photovoltaic cell 4 determined to be defective. Then, the brush 42 is pressed against the thin-film solar cell substrate 2 while the brush 42 is rotated about the rod axis by the brush control system 43 to remove the foreign matter 17.

  According to the laser scribing apparatus according to the present embodiment as described above, the same effect as in the second embodiment can be obtained. Moreover, since the foreign material 17 is removed by the brush 42, the foreign material 17 firmly adhered to the thin film solar cell substrate 2 can also be removed.

It is sectional drawing which shows the structure of the thin film solar cell module manufactured with the laser scribing apparatus which concerns on Embodiment 1. FIG. It is a perspective view which shows the structure of the thin film solar cell substrate processed with the laser scribing apparatus which concerns on Embodiment 1. FIG. 1 is a schematic side view showing a configuration of a laser scribing apparatus according to a first embodiment. It is a figure which shows the diode characteristic of the thin film photovoltaic cell formed with the laser scribing apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the diode characteristic before the repair of the thin film photovoltaic cell formed with the laser scribing apparatus which concerns on Embodiment 1. FIG. 6 is a schematic side view showing a configuration of a laser scribing apparatus according to Embodiment 2. FIG. 6 is a perspective view showing a configuration of a laser scribing apparatus according to Embodiment 2. FIG. 6 is a schematic side view showing a configuration of a laser scribing apparatus according to Embodiment 3. FIG. 6 is a schematic side view showing a configuration of a laser scribing apparatus according to Embodiment 4. FIG. It is a typical side view which shows the structure of the apparatus used as the premise of the laser scribing apparatus which concerns on this invention. It is a top view which shows operation | movement of the apparatus used as the premise of the laser scribing apparatus which concerns on this invention. It is a top view which shows operation | movement of the apparatus used as the premise of the laser scribing apparatus which concerns on this invention. It is a typical side view which shows operation | movement of the apparatus used as the premise of the laser scribing apparatus which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Thin film solar cell module, 2 Thin film solar cell board, 3 Transparent insulation board, 4 Thin film photovoltaic cell, 5 Transparent electrically conductive film, 6 Semiconductor light conversion layer, 7 Reflective electrode layer, 8 Protective film, 9 Extraction electrode, 10 Lead wire , 11 pattern, 12 first laser oscillator, 13 reflecting mirror, 14 condenser lens, 15 stage, 16 first laser light, 17 foreign matter, 18 laser light detector, 19 defect position storage system, 20 second laser Oscillator, 21 Second laser beam, 23 Electrical property measuring instrument, 24 Probe, 25 Light source, 26 Cover, 27 Stage position control system, 28, 28-1 to 28-3 Laser beam shape, 29 area, 30 1st Laser beam center, 31 stage feed width, 32 stage moving direction, 33 protrusion, 34 third laser oscillator, 35 third laser oscillator Laser light, between 36 laser distance control system, 37 laminated film, 38 a third laser beam center, between 39 laser distance 40 air knife 41 knife control system 42 brush, 43 brush control system.

Claims (7)

A laser that forms a plurality of solar cells by forming a groove-like pattern in which the semiconductor light conversion layer and the electrode layer are removed by laser scribing on the semiconductor light conversion layer and the electrode layer laminated on the transparent insulating substrate A scribing device,
Laser irradiation means for irradiating laser light used for the laser scribe processing from the transparent insulating substrate side ;
Shape inspection means for detecting the laser beam that has passed through the pattern and determining the presence or absence of defects in the pattern;
A light source for irradiating visible light to a single solar cell formed by the pattern;
While irradiating the visible light, measure the diode characteristics of the single solar cell, and based on the comparison between the measurement results and the diode characteristics of normal solar cells set in advance, the short leak defect Electrical property inspection means for determining the presence or absence;
Foreign matter removing means for removing foreign matter from the electrode layer side from the defective portion of the pattern of the solar battery cell determined to be defective by the shape inspection means and the electrical property inspection means,
A repairing means for repairing the defective portion of the pattern from which the foreign matter has been removed by the foreign matter removing means from the transparent insulating substrate side ,
Laser scribing device. A stage capable of transferring the solar battery substrate including the solar battery cell in at least a two-dimensional direction;
Storage means for storing, as two-dimensional coordinate information, two-dimensional coordinates corresponding to the position of the stage when it is determined that there is a defect by the shape inspection means and the electrical characteristic inspection means;
Controlling the movement of the stage based on the two-dimensional coordinate information stored in the storage means;
The laser scribing apparatus according to claim 1. A laser that forms a plurality of solar cells by forming a groove-like pattern in which the semiconductor light conversion layer and the electrode layer are removed by laser scribing on the semiconductor light conversion layer and the electrode layer laminated on the transparent insulating substrate A scribing device,
First laser irradiation means for irradiating laser light used for the laser scribe processing from the transparent insulating substrate side ;
A second laser irradiation means for irradiating the pattern with a laser beam for inspection;
Shape inspection means for detecting the inspection laser beam that has passed through the pattern and determining the presence or absence of defects in the pattern;
A light source for irradiating visible light to a single solar cell formed by the pattern;
While irradiating the visible light, measure the diode characteristics of the single solar cell, and based on the comparison between the measurement results and the diode characteristics of normal solar cells set in advance, the short leak defect Electrical property inspection means for determining the presence or absence;
Foreign matter removing means for removing foreign matter from the electrode layer side from the defective portion of the pattern of the solar battery cell determined to be defective by the shape inspection means and the electrical property inspection means,
A repairing means for repairing a defective portion of the pattern from which the foreign matter has been removed by the foreign matter removing means from the transparent insulating substrate side ;
The distance between the center of the laser beam for laser scribe processing and the center of the beam of laser beam for inspection is defined as N (the processing feed pitch N of the laser scribe processing by the first laser irradiation means). N: an integer greater than or equal to two)
Laser scribing device. The repair means includes
Including the laser irradiation means for irradiating the defective portion of the pattern of the solar battery cell from which the foreign matters have been removed by the foreign matter removing means with laser light used for the laser scribing process,
The laser scribing apparatus according to claim 1 or 2. The foreign matter removing means includes
Irradiating the foreign matter with laser light for foreign matter removal,
The laser scribing apparatus according to any one of claims 1 to 4. The foreign matter removing means includes
Blowing air on the foreign material,
The laser scribing apparatus according to any one of claims 1 to 4. The foreign matter removing means includes
Pressing a brush against the foreign object,
The laser scribing apparatus according to any one of claims 1 to 4.

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