Laser scribing system and method for solar cell

Abstract

The invention discloses a laser scribing system of a solar cell. The laser scribing system comprises a fixing device, a laser emitting device, an image collecting device, a control system and a real-time zooming system. The fixing device is used for fixing a solar cell substrate to be scribed at a preset position, the laser emitting device is used for providing laser, the image collecting device is used for collecting the deformation quantity of the solar cell substrate, and the control system is used for determining scribing information according to the collected deformation quantity. And the scribing device is used for receiving the scribing information and transmitting the scribing information to the real-time zooming system, and the real-time zooming system is used for receiving the laser emitted by the laser emitting device, adjusting the position of a laser light emitting focus according to the scribing information and scribing the solar cell substrate. The scribing of the deformation part of the substrate exceeding 2mm / m can be effectively solved, the power generation efficiency and the yield of the substrate are improved, and the production cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of solar cells, and in particular to a laser scribing system and method for solar cells. Background Art

[0002] Thin-film solar cells have the advantages of high efficiency, stable power generation and low material cost, and are very likely to replace silicon cells in the future. At present, in the manufacturing process of thin-film solar cells, the separation of sub-cells by laser scribing or mechanical scribing is an important process. However, in the laser separation sub-cell scribing process, especially the thin-film solar cells using glass substrates as substrates, are easily affected by the previous process, and the substrates often have different degrees of deformation, most of which are between 0.5 and 4 mm / m. The existing laser scribing technology can only solve the substrates with deformation less than 2 mm / m. When the substrate deformation exceeds 2 mm / m, the part with deformation exceeding 2 mm / m will be outside the effective focal length of the laser, resulting in missed scribing, which directly affects the power generation efficiency of the substrate and affects the product yield. Summary of the invention

[0003] In order to solve the defects in the prior art, the present invention provides a laser scribing system and method for solar cells, which can effectively solve the scribing of the deformed part of the substrate exceeding 2mm / m, improve the power generation efficiency and yield of the substrate, and save production costs.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a laser scribing system for a solar cell, the laser scribing system comprising a fixing device, a laser emitting device, an image acquisition device, a control system and a real-time zoom system;

[0006] The fixing device is used to fix the solar cell substrate to be scribed at a preset position, the laser emitting device is used to provide laser, the image acquisition device is used to acquire the deformation of the solar cell substrate, the control system is used to determine the engraving information according to the acquired deformation, and transmit the engraving information to the real-time zoom system, the real-time zoom system is used to receive the laser emitted by the laser emitting device, and adjust the position of the laser light emitting focus according to the engraving information, so as to engrave the solar cell substrate.

[0007] Optionally, a beam correction device is further provided between the laser emitting device and the real-time zoom system. In some embodiments of the present invention, the beam correction device is a beam expansion collimator. The laser emitted by the laser emitting device passes through the beam expansion collimator and is then received by the real-time zoom system. The purpose is to maintain the collimation of the beam between the laser emitting device and the real-time zoom system, and to be able to change the laser beam diameter and divergence angle to improve the accuracy and stability of the engraving.

[0008] Optionally, the deformation amount of the solar cell substrate collected by the image acquisition device is a deformation amount perpendicular to the moving direction of the solar cell substrate. In some embodiments of the present invention, the image acquisition device is a high-speed camera, and the high-speed camera is used for snapshot measurement.

[0009] Optionally, the real-time zoom system includes one or more movable lenses, and the lens plane is perpendicular to the direction of the laser received by the real-time zoom system. Furthermore, when there are multiple lenses, the multiple lenses are arranged in parallel at intervals. Furthermore, the lens is arranged on a motion rail for movement. In the present invention, one or more lenses are mainly determined according to actual needs, according to the size and area of ​​the substrate, and can be measured in different areas, so there are different numbers of lenses. Such measurement is more accurate, and the data of all lenses can be integrated together to achieve a balance value, and the focal length can be calibrated or moved according to the average value to achieve an overall balance, that is, no matter one or more of the principles are the same, the technical effect of the present invention can be achieved.

[0010] Optionally, the real-time zoom system also includes a moving device, which is used to move the lens. In the present invention, the control system transmits the engraving information to the moving device of the real-time zoom system to drive the lens displacement. In some embodiments of the present invention, the moving device is a servo motor, and the lens is set on a motion guide rail. The motion guide rail is controlled by the servo motor to control the moving distance of the lens. The servo motor is synchronously started to the place where the deformation is large, and the lens is driven by the motor to move to change the focal position of the light output, thereby ensuring that the effective energy part of the focus of the light output is always on the film layer of the solar cell substrate, and the film layer can be effectively engraved to meet the process requirements. The servo motor drives the lens to move a tiny distance within 0.1 seconds to move the focus by 2mm, which is sufficient to meet the change of focus when passing through the part of the substrate with large deformation during high-speed engraving. After passing through the area with large deformation, the servo motor is controlled to move again to restore to the normal deformation state to continue engraving.

[0011] Optionally, a total reflector is provided between the laser light outlet of the real-time zoom system and the fixing device. The total reflector can be used to deflect the light beam according to the designed route and direction. In some embodiments of the present invention, the total reflector is a 45-degree total reflector.

[0012] In a second aspect, the present invention provides a laser scribing method for a solar cell, wherein the laser scribing system is used to perform scribing, and the method comprises the following steps:

[0013] The fixing device fixes the solar cell substrate to be scribed at a preset position;

[0014] The laser emitting device provides laser light;

[0015] The image acquisition device acquires the deformation amount of the solar cell substrate;

[0016] The control system determines the marking information according to the collected deformation amount, and transmits the marking information to the real-time zoom system;

[0017] The real-time zoom system receives the laser emitted by the laser emitting device and adjusts the position of the laser light emitting focus according to the scribing information to scribble the solar cell substrate.

[0018] The beneficial effects of the present invention are:

[0019] The laser scribing system for solar cells of the present invention can carry out the laser scribing process normally when the deformation of the substrate exceeds 2 mm / m, and can effectively solve the scribing of the deformed part exceeding 2 mm / m (and is also compatible with substrates with deformation less than 2 mm / m), thereby improving the power generation efficiency and yield of the substrate and saving production costs.

[0020] At present, the existing technology often uses a long focal length field lens for laser scribing, which does not have a zoom function under high-speed dynamic conditions and cannot meet the requirements of substrate scribing under conditions where the substrate deformation exceeds 1.8 mm / m. The laser scribing method used in the present invention can achieve film scribing of substrates with large deformation under high-speed dynamic conditions, thereby increasing the yield of the product and improving the performance of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a laser scribing system of Example 1;

[0022] Figure 2 This is a detailed schematic diagram of the internal structure of the real-time zoom system;

[0023] Figure 3 is a schematic diagram of a laser scribing system according to Example 2;

[0024] Figure 4 It is a comparison diagram of the engraving effect of Example 3 and Comparative Example 1. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solution of the invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] Example 1

[0028] This embodiment is a laser scribing system for solar cells. The schematic diagram of the laser scribing system is shown in FIG. Figure 1 As shown, the system includes a fixing device 1, a laser emitting device 2, an image acquisition device 3, a control system 4 and a real-time zoom system 5;

[0029] The fixing device 1 is used to fix the solar cell substrate 6 to be scribed at a preset position, the laser emitting device 2 is used to provide laser, the image acquisition device 3 is used to acquire the deformation of the solar cell substrate 6, the control system 4 is used to determine the engraving information according to the acquired deformation, and transmit the engraving information to the real-time zoom system 5, the real-time zoom system 5 is used to receive the laser emitted by the laser emitting device 2, and adjust the position of the laser light emitting focus according to the engraving information, so as to engrave the solar cell substrate 6.

[0030] The specific contents of each part of the laser scribing system are as follows:

[0031] The fixing device 1 is a conventional positioning method in the art. In actual production, the fixing device 1 can be applied to a conventional conveyor belt in the art to achieve the purpose of batch marking.

[0032] The laser emitted by the laser emitting device 2 is a laser with a wavelength commonly used in the art.

[0033] Image acquisition device 3: The deformation of the solar cell substrate 6 acquired by the image acquisition device 3 is a deformation perpendicular to the moving direction of the solar cell substrate 6. Specifically, the deformation is a deformation based on the up and down fluctuations in the thickness direction of the substrate. In this embodiment, the image acquisition device 3 is a high-speed camera, which is used for snapshot measurement.

[0034] Control system 4: used to determine the engraving information after calculating and analyzing the deformation variables collected by the image acquisition device 3. The control system 4 can be any device that can convert the deformation variables into data and feed it back to the real-time zoom system 5. In this embodiment, the calculation and analysis mainly refers to the measured distance according to the actual warpage in proportion, such as ordinary warpage: bowgen = 2mm / m. Warpage within 1m range within 2mm can be detected without detection. After exceeding, the excess distance is sent to the control system 4. The control system 4 includes a stepper motor. According to the excess distance, it is converted according to the pulse data of the stepper motor. The distance of one pulse of the stepper motor can be determined according to the equipment. The excess distance can be converted into pulse data, and the real-time zoom system 5 can move according to the data. Local warpage: bowloc = 3.5mm / 300mm; 300mm refers to local warpage, and this is also the same for the overall warpage change.

[0035] The specific internal schematic diagram of the real-time zoom system 5 is as follows: Figure 2 As shown: the real-time zoom system 5 contains one or more movable lenses 51 (the lens 51 is arranged on a motion guide rail 53 for movement), and a plurality of lenses are arranged in parallel at intervals; the one or more lenses 51 are all set according to the substrate size and can be adjusted according to the specific substrate, but the number does not affect the realization of the technical effect, and the technical effect described in the present invention can be achieved.

[0036] The plane of the lens 51 is aligned with the laser light (such as Figure 2 The real-time zoom system 5 further includes a moving device 52, and the moving device 52 is used to move the lens 51. The control system 4 transmits the scratch information to the moving device 52 of the real-time zoom system 5 to drive the lens 51 to move. In the embodiment of the present invention, the moving device 52 is a servo motor, and the lens 51 is set on a motion guide rail 53. The motion guide rail 53 is controlled by the servo motor to control the moving distance of the lens 51.

[0037] Example 2

[0038] Similar to Example 1, this example is a laser scribing system for a solar cell. The schematic diagram of the laser scribing system is shown in FIG. Figure 3 As shown, the system includes a fixing device 1, a laser emitting device 2, an image acquisition device 3, a control system 4 and a real-time zoom system 5, and the difference from Example 1 is that:

[0039] A beam correction device 7 is also provided between the laser emitting device 2 and the real-time zoom system 5; in the embodiment of the present invention, the beam correction device 7 is a beam expansion collimator. The laser emitted by the laser emitting device 2 passes through the beam expansion collimator and is then received by the real-time zoom system 5, maintaining the collimation of the beam between the laser emitting device 2 and the real-time zoom system 5, and being able to change the laser beam diameter and divergence angle to improve the accuracy and stability of the engraving.

[0040] A total reflector 8 is also provided between the laser light outlet of the real-time zoom system 5 and the fixing device 1, and the total reflector 8 can be tilted at any degree. In the embodiment of the present invention, the total reflector is a 45-degree total reflector. In this way, there is no need to fix the relative position of the fixing device 1 and the real-time zoom system 5, and the total reflector 8 can be used to deflect the light beam according to the designed route and direction, and the relative position can be more flexible.

[0041] Example 3

[0042] This embodiment provides a method for laser scribing of a solar cell, which uses the laser scribing system described in Embodiment 2 to perform scribing, including the following steps:

[0043] The fixing device 1 fixes the solar cell substrate 6 to be scribed at a preset position;

[0044] The image acquisition device 3 acquires the deformation amount of the solar cell substrate 6;

[0045] The laser emitting device 2 provides laser light, and the emitted laser light is corrected by the beam correcting device 7 and then enters the real-time zoom system 5;

[0046] At the same time, the control system 4 determines the marking information according to the deformation amount collected by the image acquisition device 3, and transmits the marking information to the real-time zoom system 5;

[0047] The real-time zoom system 5 adjusts the position of the laser light emitting focus according to the scribing information, specifically: the control system 4 transmits the scribing information to the moving device 52 of the real-time zoom system 5 to control the moving guide rail 53 to move the lens 51, and adjusts the position of the laser light emitting focus by moving the position of the lens 51 (;

[0048] The laser light focus is adjusted by the total reflection mirror 8 and incident on the fixing device 1 to accurately scribe the solar cell substrate 6 .

[0049] In this embodiment, the moving device 52 will be synchronously started to the place where the deformation of the solar cell substrate is large, and the lens 51 will be driven to move through the moving guide rail 53 to change the focal position of the light output, thereby ensuring that the effective energy part of the focal point of the light output is always on the film layer of the solar cell substrate 6, which can effectively scribe the film layer and meet the process requirements.

[0050] The moving device 52 of this embodiment adopts a servo motor. The servo motor drives the lens 51 to move a small distance within 0.1 seconds to move the focus by 2mm, which is enough to meet the change of focus when passing through the part of the substrate with large deformation during high-speed engraving. After passing through the area with large deformation, the servo motor is controlled to move again to restore to the normal deformation state to continue engraving.

[0051] Comparative Example 1

[0052] The same as the first embodiment, except that the real-time zoom system is not used, and laser direct scribing is used.

[0053] Effect Example 1

[0054] The scribed lines obtained in Example 3 and the scribed lines obtained in Comparative Example 1 were tested. Figure 4 It can be seen that ① is obtained in Example 3, and P1 / P2 / P3 can be completely and evenly engraved; ② is obtained in Comparative Example 1, and the engraved lines are uneven, some are thick and some are thin, and there is a situation where the engraved lines are not cut, which affects the power generation efficiency and safety. It shows that the engraving method of the present invention can monitor the distance between the lens and the working point in real time through the zoom system to keep it consistent, and adjust the distance in real time according to the different warping of the substrate, so as to achieve the same physical focal length, solve the engraving of the deformed part of the substrate exceeding 2mm / m, improve the power generation efficiency and yield of the substrate, and save production costs.

[0055] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A laser scribing system for a solar cell, characterized in that: The laser scribing system includes a fixing device, a laser emitting device, an image acquisition device, a control system and a real-time zoom system; The fixing device is used to fix the solar cell substrate to be scribed at a preset position, the laser emitting device is used to provide laser, the image acquisition device is used to acquire the deformation of the solar cell substrate, the control system is used to determine the engraving information according to the acquired deformation, and transmit the engraving information to the real-time zoom system, the real-time zoom system is used to receive the laser emitted by the laser emitting device, and adjust the position of the laser light emitting focus according to the engraving information, so as to engrave the solar cell substrate.

2. The laser scribing system according to claim 1, characterized in that: The real-time zoom system includes one or more movable lenses, and the plane of the lens is perpendicular to the direction of the laser received by the real-time zoom system.

3. The laser scribing system according to claim 1, characterized in that: The real-time zoom system includes a plurality of movable lenses, and the plurality of movable lenses are arranged in parallel with each other.

4. The laser scribing system according to claim 2 or 3, characterized in that: The lens is arranged on a motion guide rail for movement.

5. The laser scribing system according to claim 4, characterized in that: The real-time zoom system further comprises a moving device, which is used to move the lens. The control system transmits the scratch information to the moving device of the real-time zoom system to drive the lens displacement.

6. The laser scribing system according to claim 1, characterized in that: A beam correction device is also arranged between the laser emitting device and the real-time zoom system.

7. The laser scribing system according to claim 6, characterized in that: The light beam correction device is a light beam expansion collimator.

8. The laser scribing system according to claim 1, characterized in that: A total reflective mirror is arranged between the laser light outlet of the real-time zoom system and the fixing device.

9. The laser scribing system according to claim 8, characterized in that: The total reflector is a 45-degree total reflector.

10. A laser scribing method for a solar cell, characterized in that: The laser scribing system according to claim 1 is used for scribing, comprising the following steps: The fixing device fixes the solar cell substrate to be scribed at a preset position; The laser emitting device provides laser light; The image acquisition device acquires the deformation amount of the solar cell substrate; The control system determines the marking information according to the collected deformation amount, and transmits the marking information to the real-time zoom system; The real-time zoom system receives the laser emitted by the laser emitting device and adjusts the position of the laser light emitting focus according to the scribing information to scribble the solar cell substrate.

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