Laser scribing device and laser scribing method

Abstract

The present application discloses a laser scribing device and a laser scribing method. The laser scribing device is used to laser scribing the substrate of a thin-film solar cell, and includes a mobile scribing module and a control module. The mobile scribing module includes a laser emitting unit, a reflector, a reflector driving unit and a rangefinder. The reflector is used to reflect the laser from the laser emitting unit and direct the reflected laser vertically onto the processing surface of the substrate. The reflector driving unit is used to drive the reflector to move in the current scribing direction, and adjust the focal position of the laser by adjusting the position of the reflector in the current scribing direction. The rangefinder is used to measure the current position to be scribed on the processing surface to obtain a distance value. The control module is used to control the reflector driving unit to adjust the position of the reflector in the current scribing direction according to the distance value of the current position to be scribed. The structure of adjusting the laser focus of the present application is simple, which is conducive to reducing the cost of the scribing device.

Description

Technical Field

[0001] The present application relates to the field of solar cells, and in particular to a laser scribing device and a laser scribing method. Background Art

[0002] The production of perovskite solar cells (PSCs) requires laser scribing to divide a large cell into several sub-cells. During processing, the laser's focus point has a certain depth range (i.e., focal depth) to achieve consistent processing results. Exceeding this range results in poor product quality. Therefore, laser processing requires constant focus relative to the glass substrate. Due to the large surface area of ​​the cell's glass substrate, the substrate itself exhibits a certain degree of curvature, which can sometimes exceed the laser's focal depth range, resulting in defocus. To address this issue, the industry typically uses a highly adjustable mechanical structure with multiple supports to correct for glass flatness. However, this solution requires high structural design precision, increasing equipment costs. Furthermore, each piece of equipment must be calibrated and regularly maintained, which is time-consuming and labor-intensive. Furthermore, if the glass edge is warped, correction cannot be achieved.

[0003] Perovskite cells require three laser scribing processes (P1, P2, and P3). These lines require extremely high parallelism accuracy, typically ≤15µm in the industry. The current solution involves using a camera to locate the two ends of P1 before the second scribing. A second scribing process is then performed mechanically or through motor interpolation. The same method is used to locate the two ends of P2 before the third scribing. However, this approach cannot guarantee parallelism among the three lines, and precision cannot be controlled. Furthermore, multiple positioning operations significantly impact production efficiency. Summary of the Invention

[0004] The purpose of the present application is to provide a laser scribing device and a laser scribing method, which can scribing the substrate glass of solar cells with different curvatures.

[0005] To achieve the above-mentioned objectives, the present application provides a laser scribing device for laser scribing a substrate of a thin-film solar cell, comprising a movable scribing module and a control module, wherein the movable scribing module comprises a laser emitting unit, a reflector, a reflector driving unit, and a rangefinder; the reflector is configured to reflect laser light from the laser emitting unit and direct the reflected laser light perpendicularly toward a processing surface of the substrate; the reflector driving unit is configured to drive the reflector to move in a current scribing direction, and to adjust the focal position of the laser light by adjusting the position of the reflector in the current scribing direction; the rangefinder is configured to measure the current position to be scribed on the processing surface to obtain a distance value; and the control module is configured to control the reflector driving unit to adjust the position of the reflector in the current scribing direction according to the distance value of the current position to be scribed.

[0006] Optionally, the mobile marking module also includes a high-speed camera, which is used to capture the position of the previous line that has been marked in real time and feed it back to the control module when marking the current position to be marked. The control module controls the relative movement of the mobile marking module and the substrate based on the position information of the previous line, so as to adjust the distance between the laser processing point and the previous line in real time.

[0007] Optionally, the center of the field of view of the high-speed camera in the current marking direction is the processing point of the laser or is aligned with the processing point of the laser. When marking the current position to be marked, the high-speed camera captures the position of the previous line corresponding to the center of the field of view in real time and feeds back to the control module. The control module controls the relative movement of the mobile marking module and the substrate in real time based on the position of the previous line corresponding to the center of the field of view.

[0008] Optionally, the laser emitting unit includes a beam combiner and a light source, and the beam combiner reflects the laser from the light source to the reflector; the high-speed camera and the reflector are arranged on opposite sides of the beam combiner, and the shooting direction of the high-speed camera is the same as the direction of the laser reflected from the beam combiner to the reflector, and the high-speed camera is used to capture the image of the beam combiner in real time to obtain the distance value between the previous line and the position facing the processing point and the processing point, and the control module uses the distance value to control the relative movement of the moving scribing module and the substrate in real time.

[0009] Optionally, the mobile scribing module further includes a driving motor, which is used to drive the movement of the beam combiner, and a closed-loop feedback control is performed between the high-speed camera and the driving motor.

[0010] Optionally, closed-loop feedback control is performed between the rangefinder and the reflector drive unit.

[0011] In order to achieve the above object, the present application further provides a laser scribing method, which is implemented based on the above laser scribing device and includes the following steps:

[0012] Controlling the relative movement of the movable scribing module and the substrate so that the movable scribing module corresponds to the current position to be scribed on the processing surface;

[0013] Measuring the distance of the current position to be marked to obtain a current distance value;

[0014] Controlling the reflector driving unit to adjust the position of the reflector in the current scribing direction according to the current distance value, so as to adjust the focal position of the laser;

[0015] Controlling the mobile marking module to mark the current position to be marked in the current marking direction;

[0016] Repeat the above steps.

[0017] Optionally, controlling the mobile marking module to mark the current position to be marked in the marking direction includes:

[0018] Real-time capture of the coordinates of the position where the previous line is aligned with the laser processing point;

[0019] Based on the coordinates of the position where the previous line is aligned with the processing point of the laser, the relative movement of the moving scribing module and the substrate is controlled in real time.

[0020] In the embodiment of the present application, a rangefinder measures the distance to the current position to be marked on the processing surface to obtain a distance value. Based on the distance value of the current position to be marked, the control module controls the reflector drive unit to adjust the position of the reflector in the current marking direction, thereby achieving the purpose of adjusting the focal position of the laser. The focus adjustment structure of the present application is simple, which helps to reduce the cost of the marking device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the principle of laser focal length adjustment according to an embodiment of the present application.

[0022] Figure 2 This is a principle block diagram of the scribing device of this application.

[0023] Figure 3 This is a schematic diagram of the three-dimensional structure of the scribing device of this application.

[0024] Figure 4 This is a top view of the scribing device of this application.

[0025] Figure 5 This is a schematic diagram of the process of adjusting the focal position of the laser in the scribing device of this application.

[0026] Figure 6 This is another schematic diagram of the process of adjusting the focal position of the laser in the scribing device of the present application. DETAILED DESCRIPTION

[0027] In order to explain the technical content, structural features, achieved objectives and effects of this application in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0028] See also Figures 1 to 4 After the laser is emitted from the laser light source for a certain distance, the light will converge at a point (just like a magnifying glass focuses the light), which is the focus F1 of the laser. In the figure, the laser is incident from the left and is reflected by the reflector 12 onto the substrate B1. By adjusting the reflector 12 to move left and right, the focus F1 can be adjusted to fall behind the substrate B1 (point A), on the substrate B1 (point B) or in front of the substrate B1 (point C). It can be understood that the adjustment of the position of the reflector 12 can be ignored in actual operation and does not affect the actual marking. Because the glass of the substrate B1 itself has a certain curvature, in actual operation, the glass of the substrate B1 may also bend to point C. At this time, the reflector 12 can be moved to the right so that the focus F1 falls on point C. The same applies to bending to point A, which will not be repeated.

[0029] The present application discloses a laser scribing device for laser scribing a substrate B1 of a thin-film solar cell, comprising a mobile scribing module 1 and a control module 2, wherein the mobile scribing module 1 comprises a laser emitting unit 11, a reflector 12, a reflector driving unit 13, a rangefinder 14 and a control module 2; the reflector 12 is used to reflect the laser from the laser emitting unit 11 and direct the reflected laser vertically onto the processing surface of the substrate B1; the reflector driving unit 13 is used to drive the reflector 12 to move in the current scribing direction, and adjust the focal position of the laser by adjusting the position of the reflector 12 in the current scribing direction; the rangefinder 14 is used to measure the current position to be scribed on the processing surface to obtain a distance value; the control module 2 is used to control the reflector driving unit 13 to adjust the position of the reflector 12 in the current scribing direction according to the distance value of the current position to be scribed.

[0030] In the present application, "the reflected laser is directed perpendicularly to the processing surface of the substrate B1" means assuming that the processing surface is a complete plane, and setting the incident direction of the reflected laser to be perpendicular to the plane. The current position to be scribed is the linear area along the current scribing direction. During scribing, the mobile scribing module 1 of the scribing device moves horizontally to the position corresponding to the current position to be scribed after completing the scribing of the previous scribing position. The rangefinder 14, as a component of the mobile scribing module 1, also moves from the position corresponding to the previous scribing position to the position corresponding to the current scribing position to measure the distance corresponding to the current scribing position. In this way, the curvature of the substrate B1 can be fully considered, and the distance can be measured for each scribing position separately. Afterwards, the reflector drive unit 13 can be controlled to adjust the position of the reflector 12 in the scribing direction according to the distance value obtained by the distance measurement to adjust to obtain a better laser focus position.

[0031] In the embodiment of the present application, the rangefinder 14 measures the distance of the current position to be marked on the processing surface to obtain a distance value. The control module 2 controls the reflector drive unit 13 to adjust the position of the reflector 12 in the current marking direction based on the distance value of the current position to be marked, thereby achieving the purpose of adjusting the focal position of the laser. The focus adjustment structure of the present application is simple, which helps to reduce the cost of the marking device.

[0032] See also Figures 1 to 4 In some embodiments, if the distance value measured by the rangefinder 14 exceeds a preset range, the control module 2 adjusts the position of the reflector 12 in the marking direction by adjusting the reflector driving unit 13. If the distance value measured by the rangefinder 14 is within the preset range, the control module 2 notifies the rangefinder 14 to perform the next distance measurement.

[0033] See also Figures 1 to 4 In some embodiments, the mobile scribing module 1 further includes a high-speed camera 15. This camera is used to capture the position of the previous line in real time while scribing the current line to be scribed and to provide feedback to the control module 2. Based on this positional information of the previous line, the control module 2 controls the relative movement of the mobile scribing module 1 and substrate B1 to adjust the distance between the laser processing point and the previous line in real time. This real-time adjustment of the distance between the laser processing point and the previous line allows for controllable parallelism between the previous line and the current line to be scribed at any position.

[0034] Optionally, the center of the field of view of the high-speed camera 15 in the current marking direction is the processing point of the laser or is aligned with the processing point of the laser. When marking the current position to be marked, the high-speed camera 15 captures the position of the center of the field of view corresponding to the previous line in real time and feeds it back to the control module 2. The control module 2 controls the relative movement of the mobile marking module 1 and the substrate B1 in real time based on the position of the center of the field of view corresponding to the previous line.

[0035] Specifically, the laser emitting unit 11 includes a beam combining mirror 111 and a light source 112. The beam combining mirror 111 reflects the laser from the light source 112 to the reflector 12. The high-speed camera 15 and the reflector 12 are arranged on opposite sides of the beam combining mirror 111. The shooting direction of the high-speed camera 15 is the same as the direction of the laser reflected from the beam combining mirror 111 to the reflector 12. The high-speed camera 15 is used to capture the image of the beam combining mirror 111 in real time to obtain the distance value between the previous line and the position facing the processing point and the processing point. The control module 2 controls the relative movement of the moving marking module 1 and the substrate B1 in real time based on the distance value.

[0036] More specifically, the mobile marking module 1 further includes a drive motor 16 , which is used to drive the movement of the beam combiner 111 , thereby moving the position of the processing point. Closed-loop feedback control is performed between the high-speed camera 15 and the drive motor 16 .

[0037] Optionally, a focusing mirror 113 is provided between the beam combining mirror 111 and the reflector 12. The beam combining mirror 111 reflects the laser from the light source 112 to the focusing mirror 113, and the focusing mirror 113 then focuses the laser onto the reflector 12. The drive motor 16 is used to drive the focusing mirror 113 and the beam combining mirror 111 to move simultaneously.

[0038] See also Figures 1 to 4 In some embodiments, closed-loop feedback control is performed between the rangefinder 14 and the reflector driving unit 13 .

[0039] See also Figures 1 to 5 The present application also discloses a laser scribing method, which is implemented based on the above-mentioned laser scribing device and includes the following steps:

[0040] S1, controlling the relative movement of the mobile scribing module 1 and the substrate B1, so that the mobile scribing module 1 corresponds to the current position to be scribed on the processing surface;

[0041] S2, measuring the distance of the current position to be marked to obtain the current distance value;

[0042] S3, controlling the reflector driving unit 13 to adjust the position of the reflector 12 in the current scribing direction according to the current distance value, so as to adjust the focal position of the laser;

[0043] S4, controlling the mobile marking module 1 to mark the current position to be marked in the current marking direction;

[0044] S5, repeat steps S1 to S4.

[0045] See also Figures 1 to 6 In some embodiments, controlling the mobile marking module 1 to mark the current position to be marked in the marking direction includes:

[0046] S41, capturing the coordinates of the position where the previous line is aligned with the laser processing point in real time;

[0047] S42, based on the coordinates of the position where the previous line is aligned with the processing point of the laser, the relative movement of the mobile scribing module 1 and the substrate B1 is controlled in real time.

[0048] The above disclosure is only the preferred embodiment of the present application, which certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the scope of the patent of the present application are still within the scope covered by the present application.

Claims

1. A laser scribing device for laser scribing a substrate of a thin film solar cell, characterized in that: The invention comprises a mobile scribing module and a control module, wherein the mobile scribing module comprises a laser emitting unit, a reflector, a reflector driving unit and a rangefinder; the reflector is used to reflect the laser from the laser emitting unit and direct the reflected laser vertically toward the processing surface of the substrate; the reflector driving unit is used to drive the reflector to move in the current scribing direction, and adjust the focal position of the laser by adjusting the position of the reflector in the current scribing direction; the rangefinder is used to measure the distance of the current position to be scribed on the processing surface to obtain a distance value; The control module is used to control the reflector drive unit to adjust the position of the reflector in the current marking direction according to the distance value of the current position to be marked; The mobile scribing module further includes a high-speed camera, which is used to capture the position of the previous line that has been marked in real time when marking the current position to be marked and feed it back to the control module. The control module controls the relative movement of the mobile scribing module and the substrate based on the position information of the previous line, so as to adjust the distance between the laser processing point and the previous line in real time; In which, the laser emitting unit includes a beam combiner and a light source, and the beam combiner reflects the laser from the light source to the reflector; the high-speed camera and the reflector are arranged on opposite sides of the beam combiner, and the shooting direction of the high-speed camera is the same as the direction of the laser reflected from the beam combiner to the reflector. The high-speed camera is used to capture the image of the beam combiner in real time to obtain the distance value between the previous line and the position facing the processing point and the processing point, and the control module uses the distance value to control the relative movement of the mobile scribing module and the substrate in real time.

2. The laser scribing device according to claim 1, wherein: The center of the field of view of the high-speed camera in the current marking direction is the processing point of the laser or is aligned with the processing point of the laser. When marking the current position to be marked, the high-speed camera captures the position of the previous line corresponding to the center of the field of view in real time and feeds back to the control module. The control module controls the relative movement of the mobile marking module and the substrate in real time based on the position of the previous line corresponding to the center of the field of view.

3. The laser scribing device according to claim 1, wherein: The mobile scribing module further includes a driving motor, which is used to drive the movement of the beam combiner mirror. Closed-loop feedback control is performed between the high-speed camera and the driving motor.

4. The laser scribing device according to claim 1, wherein: Closed-loop feedback control is performed between the rangefinder and the reflector driving unit.

5. A laser scribing method, characterized in that: The laser scribing method is implemented based on the laser scribing device according to any one of claims 1 to 4, and the method comprises the following steps: Controlling the relative movement of the movable scribing module and the substrate so that the movable scribing module corresponds to the current position to be scribed on the processing surface; Measuring the distance of the current position to be marked to obtain a current distance value; Controlling the reflector driving unit to adjust the position of the reflector in the current scribing direction according to the current distance value, so as to adjust the focal position of the laser; Controlling the mobile marking module to mark the current position to be marked in the current marking direction; Repeat the above steps.

6. The laser scribing method according to claim 5, wherein: The controlling the mobile marking module to mark the current position to be marked in the marking direction includes: Real-time capture of the coordinates of the position where the previous line is aligned with the laser processing point; Based on the coordinates of the position where the previous line is aligned with the processing point of the laser, the relative movement of the moving scribing module and the substrate is controlled in real time.

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