JP5809424B2 - Laser processing apparatus and laser processing method - Google Patents

Description

  The present invention relates to a laser processing apparatus and a laser processing method for processing a substrate to be processed used in a solar cell having a substrate and a thin film disposed on the substrate.

  Conventionally, in a manufacturing process of a thin film solar cell, first, a transparent thin film is formed on a substrate, and then a scribe line is formed by a scribe process, and the transparent thin film is formed on a plurality of transparent electrodes.

  Next, a photoelectric conversion film is formed by a film forming apparatus. At this time, the substrate is heated to a high temperature. Next, the reference mark formed on the substrate and the already processed scribe line are analyzed by the image processing device, the position and inclination of the substrate are measured, and photoelectric conversion is performed based on the position information corrected by the measurement result. The film is processed by laser light, and scribe lines are formed at intervals of several tens of μm along scribe lines (processed lines) formed on the transparent thin film.

  Next, a metal film is formed by a film forming apparatus. Even in this step, the substrate is heated to a high temperature. Next, similarly to the process after the photoelectric conversion film is formed by the film forming apparatus, the metal film is processed by the laser beam, and several tens of lines are formed along the scribe (processed line) line formed on the photoelectric conversion film. Scribe lines are formed at intervals of μm.

  As described above, when the thin film is formed by the film forming apparatus, the substrate becomes high temperature. When the thin film is scribed by laser light without sufficiently cooling the substrate, the reference scribe line is caused by the thermal expansion of the substrate. As a result, a scribe line is formed at a position shifted without being along, resulting in a decrease in the power generation region due to an increase in the interval between the scribe lines, and the product performance of the manufactured thin film solar cell is deteriorated. In addition, if the scribe lines overlap, power generation itself cannot be performed. On the other hand, if a cooling time for cooling the substrate is provided, the production tact will be reduced.

  In this regard, as in Patent Document 1, the position of the scribe line of the first layer is sequentially measured by the processing line measuring apparatus, and the first layer stacked on the first layer is based on the measured position of each scribe line. It is also conceivable that a new scribe line corresponding to the scribe line is formed in two layers along the scribe line. However, it takes a lot of time to measure all of the scribe lines. It is also possible to shorten the time during which only measurement is performed by simultaneously performing processing while measuring the scribe line. In this case, however, high-performance measurement that enables extremely high-speed processing is possible. A device is required. It is desired to provide a laser processing apparatus capable of forming a new scribe line along a scribe line at low cost without using such a processing line measuring apparatus.

JP 2007-048835 A

  The present invention has been made in consideration of such points, and a laser processing apparatus capable of preventing a decrease in production tact while maintaining the product performance of a thin film solar cell to be manufactured in a high state, It aims to provide at low cost.

The present invention relates to a laser processing apparatus for processing a substrate to be used for a solar cell having a substrate and a thin film disposed on the substrate, a holding unit for holding the substrate to be processed, and a substrate on the substrate to be processed. A detection unit that detects a position of a reference point; a control unit that includes a calculation unit that calculates a position of a processed line that has already been processed on the substrate to be processed based on a detection result of the detection unit; A laser irradiation unit that irradiates the thin film of the substrate with laser light, and a processing moving unit that moves at least one of the holding unit and the laser irradiation unit by a control unit according to a calculation result of the calculation unit; And the calculation unit compares the position of the reference point on the substrate to be processed at room temperature with the position of the reference point on the substrate to be thermally expanded, so that the thermal expansion is performed on the substrate to be processed. Said processing in Calculates the position of the saw line, when the calculating unit calculates the position of the processed line of the processed substrate was thermally expanded, using Δα = Δα0 × d / D, where, [Delta] [alpha] after thermal expansion , Δα0 is the amount of change in the outer reference line after thermal expansion, D is the distance between the central reference line before thermal expansion and the outer reference line, and d is the central reference line before thermal expansion. The laser processing apparatus is characterized in that the distance between the processed line is a distance .

  The present invention is the laser processing apparatus, wherein the detection unit detects three or more points on an outer peripheral reference line along one side of the substrate to be processed as a reference point.

  The present invention is the laser processing apparatus, wherein the detection unit detects three or more points on an outer reference line along another side adjacent to one side of the substrate to be processed as a reference point. .

  In the present invention, the detection unit has, as reference points, four outer peripheral reference lines along the four sides of the substrate to be processed, and two central reference lines parallel to the four sides of the substrate to be processed that pass through the center of the substrate to be processed. The laser processing apparatus is characterized by detecting desired three or more points out of a total of nine points of the eight intersection points and the center point of the substrate to be processed.

  In the present invention, the control unit detects the position of the reference point on the substrate to be processed by the detection unit immediately before irradiating the thin film of the substrate to be processed by the laser irradiation unit, and the calculation unit detects the detection unit. The laser processing apparatus is characterized in that the position of a processed line already processed on a substrate to be processed is calculated based on a result.

  In the present invention, the control unit detects the position of the reference point on the substrate to be processed by the detection unit while irradiating the thin film of the substrate to be processed by the laser irradiation unit, and the calculation unit detects the detection result of the detection unit. The position of the processed line already processed on the substrate to be processed is calculated based on the above.

  In the present invention, the control unit detects the position of the reference point on the substrate to be processed by the detection unit only for the thin film of the substrate to be processed, and the calculation unit detects the position of the reference point on the substrate to be processed based on the detection result of the detection unit. The laser processing apparatus is characterized in that the position of a processed line that has already been processed is calculated.

The present invention relates to a laser processing method for processing a substrate to be used for a solar cell having a substrate and a thin film disposed on the substrate, and a step of detecting a position of a reference point on the substrate to be processed, Based on the result, the step of calculating the position of the processed line already processed on the substrate to be processed, and the step of irradiating the thin film of the substrate to be processed with laser light, according to the calculation result, A step of moving the irradiation position of the laser beam, and in the step of calculating the position of the processed line, the position of the reference point on the substrate to be processed at room temperature and the reference point on the substrate to be thermally expanded And the position of the processed line on the processed substrate thermally expanded by the calculation unit is calculated by the calculation unit, and the calculated unit is processed on the thermally expanded substrate line When calculating the position, Δα = Δα0 × d / D is used, where Δα is the amount of change in the processed line after thermal expansion, Δα0 is the amount of change in the outer peripheral reference line after thermal expansion, and D is before thermal expansion. The distance between the center reference line and the outer periphery reference line, d is the distance between the center reference line before thermal expansion and the processed line .

  According to the present invention, the step of detecting the position of the reference point on the substrate to be processed includes detecting three or more points on the substrate to be processed and calculating the position of the processed line. In this laser processing method, an arc passing through the above points is calculated, and the arc is used when calculating the position of the processed line.

  In the present invention, the position of the reference point on the substrate to be processed is detected by the detection unit immediately before the thin film of the substrate to be processed is irradiated with laser light, and the target is detected by the calculation unit based on the detection result of the detection unit. A laser processing method is characterized in that the position of a processed line already processed on a processed substrate is calculated.

  In the present invention, the position of the reference point on the substrate to be processed is detected by the detection unit while irradiating the thin film of the substrate to be processed, and the processing unit is processed based on the detection result of the detection unit by the calculation unit. A laser processing method is characterized in that the position of a processed line already processed on a substrate is calculated.

  In the present invention, the position of the reference point on the substrate to be processed is detected by the detection unit only on the thin film of the arbitrary substrate to be processed, and the calculation unit has already detected the position of the reference point on the substrate based on the detection result of the detection unit. A laser processing method is characterized in that the position of a processed line that has been processed is calculated.

  According to the present invention, by comparing the position of the reference point on the processed substrate at room temperature with the position of the reference point on the thermally expanded substrate, the processed line on the thermally expanded processed substrate The position is calculated, and the thin film is processed with laser light according to the calculation result. For this reason, the laser processing apparatus which can prevent the fall of a production tact can be provided at low cost, maintaining the product performance of the thin film solar cell manufactured at a high state.

1 is a side sectional view showing a configuration of a laser processing apparatus according to a first embodiment of the present invention. The upper top view which showed the reference points P1-P9 on the to-be-processed substrate processed by the laser processing apparatus by the 1st Embodiment of this invention. The upper top view which showed the aspect changed with the temperature difference of the to-be-processed substrate processed by the laser processing apparatus by the 1st Embodiment of this invention. The side sectional view showing the processing mode of the processed substrate in the 1st embodiment of the present invention. The figure which shows the modification of the reference point detected by the detection part in the 1st Embodiment of this invention. The figure which shows the reference point detected by the detection part in the 2nd Embodiment of this invention. The figure which shows the modification of the reference point detected by the detection part in the 2nd Embodiment of this invention. The figure which shows the modification of the reference point detected by the detection part in the 2nd Embodiment of this invention. The figure which shows the modification of the reference point detected by the detection part in the 2nd Embodiment of this invention. The figure which shows the modification of the reference point detected by the detection part in the 2nd Embodiment of this invention. The figure which shows the modification of the reference point detected by the detection part in the 2nd Embodiment of this invention.

First Embodiment Hereinafter, an embodiment of a laser processing apparatus according to the present invention will be described with reference to the drawings. Here, FIG. 1 to FIG. 4 are diagrams showing an embodiment of the present invention.

  The laser processing apparatus of this embodiment is for processing a substrate to be processed 60 used in a solar cell having a glass substrate (substrate) 61 and a thin film 65 disposed on the glass substrate 61. Among these, the thin film 65 is provided on the transparent electrode film 62 provided on the glass substrate 61, the photoelectric conversion layer 63 containing Si or the like provided on the transparent electrode film 62, and the photoelectric conversion layer 63. And a metal electrode film 64 (see FIG. 4).

  As shown in FIG. 1, the laser processing apparatus includes a holding unit 20 that holds a substrate 60 to be processed, a detection unit 10 that detects the positions of reference points P1 to P9 (see FIG. 2) on the substrate 60 to be processed, Based on the detection result of the detection unit 10, the control unit 50 </ b> A including the calculation unit 50 that calculates the position of the scribe line (processed line) that has already been processed on the processing substrate 60, and the thin film 65 of the processing substrate 60 On the other hand, a laser irradiation unit 30 that irradiates laser light L, and a direction that includes a component orthogonal to the processing progress direction while moving the laser irradiation unit 30 along the processing progress direction by the control unit 50A according to the calculation result of the calculation unit 50 And a processing moving section 35 that moves to the position.

  Among these, the detection part 10 uses eight points (points on the glass substrate 61) P1 to P8 on the four outer peripheral reference straight lines 71 to 74 along the side of the glass substrate 61 of the substrate to be processed 60 as reference points. Detect (see FIG. 2). Note that already processed scribe lines can be used as the outer peripheral reference straight lines 71 to 74. Incidentally, as shown in FIG. 1, the detection unit 10 is provided with a detection moving unit 15 that moves the detection unit 10.

  More specifically, the detection unit 10 includes an outer peripheral reference straight line 71 (hereinafter also referred to as a first outer peripheral reference straight line 71) along one side of the glass substrate 61, and an outer peripheral reference straight line 72 ( Hereinafter, peripheral reference straight lines 73 and 74 parallel to each other along two other sides adjacent to one side of the glass substrate 61 (hereinafter also referred to as a third peripheral reference straight line 73 and a fourth outer peripheral reference). Intersections (four points) P1 to P4 with the straight line 74) and straight lines passing through the center of the glass substrate 61 and parallel to the first outer reference straight line 71 (hereinafter also referred to as first central reference straight line 81). Cross points (two points) P7, P8 of the third outer circumference reference straight line 73 and the fourth outer circumference reference straight line 74 and a straight line passing through the center of the glass substrate 61 and parallel to the third outer circumference reference straight line 73 (hereinafter referred to as the second). Also called central reference line 82) Intersection (two points) between the first outer circumferential reference line 71 and the second outer circumferential reference line 72 of the substrate 61 and P5, P6, detected as a reference point.

  Moreover, the detection part 10 also detects the center point (intersection of the 1st center reference straight line 81 and the 2nd center reference straight line 82) P9 located in the center of the glass substrate 61 as a reference point (refer FIG. 2). As the first central reference line 81 and the second central reference line 82, scribe lines that have already been processed can be used.

  By the way, although this Embodiment demonstrates using the aspect by which the laser irradiation part 30 is moved, if the laser irradiation part 30 is moved relatively with respect to the to-be-processed substrate 60, it will be restricted to this. Absent. For example, the holding unit 20 may be moved, both the holding unit 20 and the laser irradiation unit 30 may be moved, or a single moving unit may serve as a detection moving unit and a processing moving unit. Also good.

  In addition, in this Embodiment, although the detection part 10 demonstrates using the aspect which detects three points with respect to one outer periphery reference straight line 71-74, it is not restricted to this, One outer periphery reference straight line You may detect four or more positions with respect to 71-74.

Further, the calculation unit 50 calculates the positions of the reference points (nine points) P1 to P9 on the glass substrate 61 of the substrate to be processed 60 at room temperature (about 24 ° C.) in the factory, and the glass of the substrate 60 to be thermally expanded. reference point on the substrate 61 by comparing the position of the (point nine) P1 to P9, calculates the position of the scribe line consisting of TCO scribe lines 62 _T and Si scribe lines 63 _S in the substrate to be processed 60 which have thermal expansion Is configured to do.

  More specifically, the calculation unit 50 calculates the first outer peripheral reference line 71 on the substrate 60 to be thermally expanded with respect to the reference points P1, P5, and P2 (three points) on the first outer peripheral reference line 71 at room temperature. The amount of change of the upper reference points P1, P5, P2 (three points) is calculated. Subsequently, the calculation unit 50 also calculates an arc passing through the three reference points P1, P5, P2 (hereinafter also referred to as a first outer reference arc 71 ') (see FIG. 3). Similarly, the calculation unit 50 calculates from the amount of change at the time of thermal expansion of the reference points P1 to P9 on the second outer circumference reference straight line 72, the third outer circumference reference straight line 73, and the fourth outer circumference reference straight line 74 at the time of thermal expansion. An arc passing through the reference points P1 to P9 (hereinafter also referred to as a second outer reference arc, a third outer reference arc, and a fourth outer reference arc (all not shown)) is also calculated.

  And the calculation part 50 in each position of the thin film 65 located between these 1st center reference straight line 81 and 1st outer periphery reference circular arc 71 'from the 1st center reference straight line 81 and 1st outer periphery reference circular arc 71'. The position at the time of thermal expansion is also calculated (see FIG. 3).

For example, at a predetermined point A, the change amount of the first outer reference arc 71 ′ with respect to the first outer reference line 71 is Δα ₀ (maximum thermal expansion amount), and the first center reference line 81 and the first outer reference line 71 When the distance is D, the change amount Δα at the target point B on the straight line extending from the predetermined point A in the direction orthogonal to the first central reference line 81 (the distance from the first central reference line 81 is d) is ,
Δα = Δα ₀ × d / D
Can be obtained as In this example, d / D is a coefficient. However, the coefficient may be appropriately changed in consideration of properties such as an actual expansion mode of the substrate 60 to be processed. In addition, since the scribe lines are formed substantially uniformly, the coefficient may be created based on the number from the first central reference line 81 instead of the distance d. By the way, since the to-be-processed substrate 60 is thermally expanded from the center point, the first center reference straight line 81 and the second center reference straight line 82 passing through the center point remain straight.

  Similarly, the calculation unit 50 performs thermal expansion at each position of the thin film 65 located between the first center reference line 81 and the second outer reference arc from the first center reference line 81 and the second outer reference arc. Of the thin film 65 located between the second center reference line 82 and the third outer reference arc from the second center reference line 82 and the third outer reference arc. And the position at the time of thermal expansion at each position of the thin film 65 located between the second central reference line 82 and the fourth outer reference arc is also calculated from the second central reference line 82 and the fourth outer reference arc. To do.

  By the way, in the laser processing apparatus of the present embodiment, a film forming apparatus (not shown) for forming the photoelectric conversion layer 63 on the transparent electrode film 62 and a metal electrode film 64 on the photoelectric conversion layer 63 are formed. A film forming apparatus (not shown) for film formation is included. When the thin film 65 is formed by such a film forming apparatus, the substrate 60 to be processed becomes a high temperature of about 100 ° C.

  Next, the operation of the present embodiment having such a configuration will be described.

  First, a substrate to be processed 60 having a glass substrate 61 and a transparent electrode film 62 disposed on the glass substrate 61 is prepared (see FIG. 4A). Thereafter, the substrate 60 to be processed is held by the holding unit 20. At this time, in the present embodiment, the substrate to be processed 60 is held by the holding unit 20 so that the transparent electrode film 62 is positioned below the glass substrate 61. However, the present invention is not limited to this, and the substrate to be processed 60 may be held by the holding unit 20 so that the transparent electrode film 62 is positioned above the glass substrate 61.

Next, the laser beam L is irradiated from the laser irradiation unit 30 to the transparent electrode film 62 of the substrate to be processed 60 (see FIG. 1). At this time, the laser irradiation unit 30 is moved along the processing progress direction by the processing moving unit 35. As a result, the transparent electrode film 62 is processed along the processing progress direction, and a plurality of TCO scribe lines are formed on the transparent electrode film 62. 62 _T is formed (see FIG. 4B). When using scribe lines already processed as the outer reference lines 71 to 74 (outer reference arcs 71 ′ to 74 ′) and the center reference lines 81 and 82, at this time, the outer reference lines 71 to 74 and the center reference line are used. The straight lines 81 and 82 are formed by scribing. The laser irradiation unit 30, the processing moving unit 35, the detecting unit 10, and the detecting moving unit 15 are all controlled by the control unit 50A.

  Next, the position of the reference points P1 to P9 on the glass substrate 61 is detected by the detection unit 10, and the positions of the reference points P1 to P9 on the glass substrate 61 at room temperature are detected (see FIG. 2).

  Next, a photoelectric conversion layer 63 containing Si or the like is formed on the transparent electrode film 62 provided on the glass substrate 61 by a film forming apparatus (see FIG. 4C).

  Next, the position of the reference points P1 to P9 on the glass substrate 61 is detected by the detecting unit 10, and the positions of the reference points P1 to P9 on the thermally expanded glass substrate 61 are detected (see FIGS. 2 and 3). ).

Next, the position of the TCO scribe line 62 _T (processed line) that has already been processed on the processing substrate 60 is calculated by the calculation unit 50 based on the detection result. Specifically, the calculation unit 50 compares the positions of the reference points P1 to P9 on the glass substrate 61 at room temperature with the positions of the reference points P1 to P9 on the glass substrate 61 that has been thermally expanded. The position of each TCO scribe line (processed line) 62 _T on the processed substrate 60 is calculated.

That is, the calculation unit 50 causes the TCO scribe line 62 _{T to} be between the first center reference straight line 81 and the first outer periphery reference arc 71 ′ from the first center reference straight line 81 and the first outer periphery reference arc 71 ′. The position of the formed portion at the time of thermal expansion is calculated (see FIG. 3), and from the first central reference straight line 81 and the second outer peripheral reference arc, between these first central reference straight line 81 and the second outer peripheral reference arc. position at the time of thermal expansion of a portion TCO scribe lines 62 _T is formed is calculated there. Here, although TCO scribe line 62 _T is based on the assumption manner of extending along the vertical direction of the sheet of FIG. 3, TCO scribe line 62 _T along the horizontal direction of the sheet of FIG. 3 extending to If a second central reference line 82 from the third outer peripheral reference arc, these second central reference line 82 and the portion where the a and TCO scribe line 62 _T is formed between the third outer peripheral reference arc heat position when inflated is calculated, and a second central reference line 82 fourth outer peripheral reference arc, TCO scribe line 62 _T a between the second central reference line 82 and the fourth outer peripheral reference arc is formed The position at the time of thermal expansion is calculated. As a result, the position of the TCO scribe line 62 _T on the thermally expanded substrate 60 is calculated.

Next, the laser beam L is irradiated from the laser irradiation unit 30 to the photoelectric conversion layer 63 of the substrate 60 to be processed. At this time, according to the calculation result, the irradiation position of the laser beam L is moved along the machining progress direction and is also moved in a direction including a component orthogonal to the machining progress direction (drawing an arc). Is moved). As a result, the photoelectric conversion layer 63 is processed along the processing direction of travel, so that the Si scribe line 63 _S is formed on the photoelectric conversion layer 63 (see FIG. 4 (d)).

By the way, when the photoelectric conversion layer 63 is formed by the film forming apparatus, the substrate to be processed 60 becomes high temperature (about 100 ° C.), so the photoelectric conversion layer 63 is cut by the laser light L without cooling the substrate to be processed 60. Then, a position shifted without along the TCO scribe line 62 _T as a reference would be Si scribe line 63 _S is formed, the product performance is poor in thin-film solar cells produced. On the other hand, if a cooling time (for example, about 30 minutes) for cooling the workpiece substrate 60 is provided, the production tact will be reduced.

In this regard, according to the present embodiment, according to the calculation result, the irradiation position of the laser light L is moved along the machining progress direction and is also moved in a direction including a component orthogonal to the machining progress direction. without providing a cooling time for cooling the substrate to be processed 60 may be Si scribe line 63 _S is formed at a position along the TCO scribe line 62 _T. For this reason, it is possible to prevent the production tact from being lowered while maintaining the product performance of the manufactured thin-film solar cell in a high state. In addition, according to this Embodiment, since the processing line measuring apparatus like patent document 1 is not used, the laser processing apparatus which can form the new scribe line along the already processed scribe line is provided. It can be provided at low cost and is beneficial.

It is the photoelectric conversion layer 63 in the manner of processing above, the photoelectric conversion layer 63 Si scribe line 63 _S is formed, then, by a film forming device, provided in the transparent electrode film 62 photoelectric conversion layer 63 above Then, a metal electrode film 64 is formed (see FIG. 4E). (Note that subsequent steps are the same as when forming the Si scribe lines 63 _S, details will be described below is omitted.)

  Next, the position of the reference points P1 to P9 on the workpiece substrate 60 is detected by the detection unit 10 (see FIG. 2).

Next, the position of the Si scribe line (processed line) 63 _S that has already been processed on the processing substrate 60 is calculated by the calculation unit 50 based on the detection result. At this time, the calculation unit 50 compares the positions of the reference points P1 to P9 on the glass substrate 61 at normal temperature with the positions of the reference points P1 to P9 on the thermally expanded glass substrate 61, whereby the thermally expanded glass. so that the position of the Si scribe lines 63 _S on the substrate 61 is calculated. At this time, the position of the TCO scribe line 62 _T may be used as a reference instead of using the position of the Si scribe line 63 _S as a reference as in the present embodiment.

Next, the laser beam L is irradiated from the laser irradiation unit 30 to the metal electrode film 64 of the substrate 60 to be processed. At this time, the irradiation position of the laser beam L is moved in the direction including the component orthogonal to the processing progress direction while being moved along the processing progress direction according to the calculation result. As a result, the metal electrode film 64 is processed along the processing direction of travel, so that the the metal electrode film 64 Metals Clive line 64 _M is formed (see FIG. 4 (f)).

Also at this time, according to the present embodiment, the metal scribe line 64 _M can be formed at a position along the Si scribe line 63 _S without providing a cooling time for cooling the substrate 60 to be processed. . For this reason, it is possible to prevent the production tact from being lowered while maintaining the product performance of the manufactured thin-film solar cell in a high state.

  In the above-described embodiment, the description has been made using the aspect of detecting the positions of the reference points P1 to P9 on the glass substrate 61 at room temperature when calculating the thermal expansion amount. However, the present invention is not limited to this, and preset values such as design data may be used as the positions of the reference points P1 to P9 on the substrate 60 to be processed at room temperature. (In this case also, the same operational effects as those of the above-described embodiment can be obtained.).

For example, in the above embodiment, it is deposited a transparent electrode film 62 on the advance glass substrate 61, by processing the scribe line 62 _T to the transparent electrode film 62 of the substrate to be processed 60 which is a normal temperature, normal temperature in its working state Although the positions of the reference points P1 to P9 on the glass substrate 61 are detected, immediately after the transparent electrode film 62 is formed, the scribe line is processed on the substrate 60 to be processed at a high temperature. Preset values such as data can be used as the positions of the reference points P1 to P9 on the glass substrate 61 at room temperature.

  In this way, when using preset values, it is not always necessary to detect the positions of the reference points P1 to P9 on the glass substrate 61 at room temperature as in the above embodiment.

  Detection of the reference points P1 to P9 and calculation of the position of the processed line in the subsequent processing of the scribe line are performed in the same manner as in the above-described embodiment. The position to be compared at the time of calculation is a preset set value.

  Moreover, when calculating the amount of thermal expansion, a reference mark previously arranged on the substrate may be used, and the present invention includes such an aspect.

  Further, in the above-described embodiment, the case where the center reference straight lines 81 and 82 are formed by scribing when the already processed scribe line is used has been described, but in reality, the center reference straight lines 81 and 82 are not necessarily formed. You don't have to.

  Also in this case, preset values set in advance as the center reference straight lines 81 and 82 can be used. This set value may be set in advance as reference straight line data, or may be calculated from a set value set in advance with respect to the corners of the glass substrate (for example, reference points P1 to P4).

  In addition, a line passing through the region including the central portion may be assumed, without necessarily assuming a line passing through the substrate center point P9. For example, a scribe line existing near the center of the substrate as shown in FIG. 5 can be used.

Second Embodiment In the first embodiment, a mode has been described in which the detection unit 10 detects nine points of the reference points P1 to P9 on the glass substrate 61. However, the present invention is not limited to this. If position information that can calculate the thermal expansion state is obtained by comparison with the set value, it is not always necessary to detect the nine reference points P1 to P9.

  Specifically, the modes shown in FIGS. 6 to 11 are conceivable.

  As the number of detection points is smaller, the time required for detection can be reduced, and the reduction in production tact can be suppressed.

  6 to 11 show that scribing of the solar cell is often performed in a strip shape, so that the scribing is performed in parallel to the outer peripheral reference straight lines 71 and 72.

  Of course, it is conceivable that the strip is scribed in parallel with the outer reference lines 73 and 74, and when the scribe parallel to the outer reference line 71 and the scribe parallel to 73 are performed as shown in FIG. Is also applicable.

  Here, the case where scribe parallel to the outer periphery reference straight lines 71 and 72 is performed will be specifically described.

  As described above, the substrate 60 to be processed, which is held on the holding unit 20 and positioned by the positioning pins 20a, thermally expands from the substrate center point (center portion), and the vicinity of the center is hardly deformed. Therefore, by not using the reference points P7, P9, and P8 in the first embodiment and using preset setting values, each position on the glass substrate 61 can be reliably detected as in the first embodiment. It can be calculated.

  Specifically, the detection unit 10 has, as reference points, six points (points on the glass substrate 61) P1 to four outer reference straight lines 71 to 74 along the side of the glass substrate 61 of the substrate 60 to be processed. P6 is detected (see FIG. 6).

  The calculation unit 50 calculates the reference points P1, P1, P5, P5, and P2 (three points) on the first outer reference line 71 at normal temperature on the first outer reference line 71 on the substrate 60 to be thermally expanded. The amount of change of P5 and P2 (three points) is calculated. Subsequently, the calculation unit 50 calculates an arc passing through the three reference points P1, P5, and P2 (hereinafter also referred to as a first outer peripheral reference arc 71 ') (see FIG. 3).

  Similarly, the calculation unit 50 determines the arcs passing through the reference points P1, P6, and P4 at the time of thermal expansion from the amount of change at the time of the thermal expansion of the reference points P3, P6, and P4 on the second outer circumference reference line 72 ( Hereinafter, the second outer circumference reference arc) is calculated.

  Then, the calculation unit 50 calculates the first central reference straight line 81 and the first outer peripheral reference arc 71 ′ from the first central reference straight line 81 and the first outer peripheral reference arc 71 ′ at a preset setting value (design data). The position at the time of thermal expansion at each position of the thin film 65 positioned between the two is calculated (see FIG. 3).

  Similarly, the calculation unit 50 calculates each of the thin films 65 positioned between the first center reference straight line 81 and the second outer reference arc 72 ′ from the first center reference straight line 81 and the second outer reference arc 72 ′. The position at the time of thermal expansion is calculated.

  From the above, each position of the thin film 65 can be calculated as in the first embodiment.

  Further, since it is considered that the peripheral reference straight line 71 side and the 72 reference side are thermally expanded from the center of the substrate, the peripheral reference straight line 71 side is detected without detecting the reference points P3, P6, P4. It is also possible to calculate by reversing in the reverse direction (mirror reversal) using the above result.

  At this time, as the first central reference line 81, the midpoints of the reference points P1 and P3 and the midpoints of the reference points P2 and P4 are calculated without using preset values, and the first central reference line 81 is calculated. You may ask for.

  FIG. 7 shows a case where the detection unit 10 detects the reference points P1, P2, and P6.

  In FIG. 7, instead of the reference point P5 on the outer periphery reference line 71, a reference point P6 on the outer periphery reference line 72 is detected. Since the substrate to be processed 60 is subject to thermal expansion from the center of the substrate, the reference point P5 can be obtained using the detection result of the reference point P6.

  In FIG. 8, the detection unit 10 can also detect a reference point P5 on the outer circumference reference line 71 in addition to FIG. In FIG. 7, the detection result of the reference point P6 is the result of the reference point P5. However, by detecting and comparing both the reference points P5 and P6, the state of thermal expansion of the entire substrate 60 to be processed can be more accurately detected. Can be calculated.

  9 and 10 are obtained by adding a reference point P9 near the center of the substrate in addition to the detection patterns of FIGS. 6 and 8, respectively. The detection unit 10 detects the actual reference point P9 in the vicinity of the center of the substrate, thereby accurately detecting the state of thermal expansion of the substrate 60 to be processed even when the processed plate 60 is not thermally expanded symmetrically with respect to the center of the substrate. And a reduction in production tact can be suppressed as compared with the case where the reference point is nine points.

  Further, FIG. 11 shows a case where the detection unit 10 detects P7, P8, and P5 as reference points.

  In this case, the first central reference straight line 81 is calculated from the reference points P7 and P8, and the maximum thermal expansion amount can be detected by detecting the position of the reference point P5 on the outermost peripheral straight line 71 therefrom. From this result, each position on the thin film 65 can be calculated. At this time, the reference points P1 and P2 on the outermost straight line 71 are calculated as being proportional to the maximum thermal expansion amount.

Third Embodiment In the first and second embodiments, the example of detecting the state of thermal expansion and calculating the position to be scribed has been shown, but the state of thermal expansion changes over time. .

  When scribing is performed in a relatively short time, there is no problem even if the result detected immediately after the substrate 60 to be thermally expanded is arranged in the laser processing apparatus. However, when multiple film forming devices and multiple laser processing devices are connected and lined up, or when the time since film formation varies due to troubles, planned production stoppage, etc., the detection timing is It is desirable that it can be set freely.

  Therefore, the control unit 50A can set various modes, for example, modes (1), (2), and (3) as shown below for the detection timing at the time of thermal expansion.

Mode (1) Before starting scribing, all points detected by the detector 10 are detected,
The machining position is calculated.
In this case, since the correction calculation is performed first, the processing becomes simple.
Mode (2) Appropriate detection is performed during scribing.
In this case, it is possible to follow the expansion change accompanying the temperature drop during processing (depending on the elapsed time).
May be)
In addition, the correction accuracy can be ensured by detecting at the time of restart such as error stop.
Mode (3) The reference point is detected only for any substrate to be processed.
In this case, if there is little variation in shape between the substrates 60 to be processed,
Decrease in production tact can be suppressed.

  Furthermore, by measuring the elapsed time from the time when the reference point was detected as another mode, and calculating the correction value by taking into account the time-varying variation rate of thermal expansion measured in advance, the processing position is determined. It is possible to calculate with high accuracy.

DESCRIPTION OF SYMBOLS 10 Detection part 15 Detection moving part 20 Holding | maintenance part 20a Positioning pin 30 Laser irradiation part 35 Processing movement part 50 Calculation part 50A Control part 60 Substrate 61 Glass substrate (board | substrate)
62 Transparent electrode film (thin film)
62 _T TCO scribe line (processed line)
63 Photoelectric conversion layer (thin film)
63 _S Si scribe line (processed line)
64 Metal electrode film (thin film)
64 _M metal scribe line (processed line)
71 First outer circumference reference straight line 72 Second outer circumference reference straight line 73 Third outer circumference reference straight line 74 Fourth outer circumference reference straight line 81 First central reference straight line 82 Second central reference straight line L Laser beams P1 to P9 Reference point

Claims (12)

In a laser processing apparatus for processing a substrate to be used for a solar cell having a substrate and a thin film disposed on the substrate,
A holding unit for holding the substrate to be processed;
A detection unit for detecting a position of a reference point on the substrate to be processed;
Based on the detection result of the detection unit, a control unit including a calculation unit that calculates the position of a processed line that has already been processed on the substrate to be processed;
A laser irradiation unit for irradiating the thin film of the substrate to be processed with a laser beam;
According to the calculation result of the calculation unit, a control unit includes a processing moving unit that moves at least one of the holding unit and the laser irradiation unit,
The calculation unit compares the position of the reference point on the substrate to be processed at normal temperature with the position of the reference point on the substrate to be thermally expanded, thereby processing the processing on the substrate to be thermally expanded. Calculate the position of the finished line ,
The calculation unit uses Δα = Δα0 × d / D when calculating the position of the processed line on the substrate to be thermally expanded,
Where Δα is the amount of change in the processed line after thermal expansion, Δα0 is the amount of change in the outer reference line after thermal expansion, D is the distance between the central reference line and the outer reference line before thermal expansion, and d is The distance between the center reference line before thermal expansion and the processed line,
The laser processing apparatus characterized by becoming .   The laser processing apparatus according to claim 1, wherein the detection unit detects three or more points on an outer peripheral reference line along one side of the substrate to be processed as a reference point.   The laser processing apparatus according to claim 2, wherein the detection unit detects three or more points on an outer peripheral reference line along another side adjacent to one side of the substrate to be processed as a reference point. .   The detection unit, as a reference point, eight intersections of four outer reference lines along the four sides of the substrate to be processed and two central reference lines parallel to the four sides of the substrate to be processed that pass through the center of the substrate to be processed The laser processing apparatus according to claim 1, wherein desired three or more points are detected among a total of nine points of the center point of the substrate to be processed.   The control unit detects the position of the reference point on the substrate to be processed by the detection unit immediately before irradiating the thin film of the substrate to be processed by the laser irradiation unit, and based on the detection result of the detection unit by the calculation unit. The laser processing apparatus according to claim 1, wherein the position of a processed line that has already been processed on the substrate to be processed is calculated.   The control unit detects the position of the reference point on the substrate to be processed by the detection unit while irradiating the thin film of the substrate to be processed by the laser irradiation unit, and detects the position of the reference point on the substrate to be processed by the calculation unit based on the detection result of the detection unit. The laser processing apparatus according to claim 1, wherein the position of a processed line already processed on the processing substrate is calculated.   The control unit detects the position of the reference point on the substrate to be processed only by the detection unit for the thin film of the arbitrary substrate to be processed, and has already been processed on the substrate to be processed based on the detection result of the detection unit by the calculation unit. The laser processing apparatus according to claim 1, wherein the position of the processed line is calculated. In a laser processing method for processing a substrate to be used for a solar cell having a substrate and a thin film disposed on the substrate,
Detecting a position of a reference point on the substrate to be processed;
Calculating a position of a processed line already processed on the substrate to be processed based on a detection result;
Irradiating the thin film of the substrate to be processed with laser light, and moving the laser light irradiation position according to the calculation result,
In the step of calculating the position of the processed line, the calculation unit compares the position of the reference point on the substrate to be processed at normal temperature with the position of the reference point on the substrate to be thermally expanded, so that the calculation unit While calculating the position of the processed line on the expanded substrate to be processed ,
The calculation unit uses Δα = Δα0 × d / D when calculating the position of the processed line on the substrate to be thermally expanded,
Where Δα is the amount of change in the processed line after thermal expansion, Δα0 is the amount of change in the outer reference line after thermal expansion, D is the distance between the central reference line and the outer reference line before thermal expansion, and d is The distance between the center reference line before thermal expansion and the processed line,
The laser processing method characterized by becoming . The step of detecting the position of the reference point on the substrate to be processed detects three or more points on the substrate to be processed,
A step of calculating the position of the processed line, calculates an arc passing through the three or more points, according to claim 8, characterized by using the arc when calculating the position of the processed line The laser processing method as described in. Immediately before irradiating the thin film of the workpiece substrate with laser light, the detection unit detects the position of the reference point on the workpiece substrate, and the calculation unit detects the position of the reference point on the workpiece substrate based on the detection result of the detection unit. The laser processing method according to claim 8 , wherein the position of a processed line that has already been processed is calculated. While irradiating the thin film of the substrate to be processed with laser light, the detection unit detects the position of the reference point on the substrate to be processed, and the calculation unit has already detected the position of the reference point on the substrate based on the detection result of the detection unit. The laser processing method according to claim 8 , wherein the position of the processed line that has been processed is calculated. Only for the thin film of any substrate to be processed, the detection unit detects the position of the reference point on the substrate to be processed, and the calculation unit has already processed on the substrate to be processed based on the detection result of the detection unit. The laser processing method according to claim 8 , wherein the position of the finished line is calculated.

Images