Laser scribing method and apparatus

Abstract

The application provides a laser scribing method and device. The laser scribing method comprises: providing a slotting laser, a splitting laser and a deviation rectifying laser. The slotting laser is arranged on the front side of the splitting laser, and the deviation rectifying laser is arranged on the side of the splitting laser; the slotting laser scans the front end and the rear end of the battery piece along a target splitting line to form a splitting slot, and the splitting laser splits the battery piece along the target splitting line; during the splitting process: when the splitting laser scans the first section or the tail section of the target splitting line, the deviation rectifying laser is turned off; when the splitting laser scans the middle section of the target splitting line, the deviation rectifying laser is turned on, so that the light spot of the deviation rectifying laser falls on the stress compensation side of the middle section of the target splitting line and synchronously scans with the light spot of the splitting laser. The application balances the stress on both sides of the target splitting line, thereby reducing the offset between the actual splitting line formed after splitting and the target splitting line, and improving the scribing quality.

Description

Technical Field

[0001] This application relates to the field of photovoltaic cell manufacturing, specifically to a laser scribing method and apparatus. Background Technology

[0002] The production process of photovoltaic modules involves a multi-segmentation process for solar cells, for example... Figure 1 As shown, the entire solar cell is diced into three segments. The current mainstream dicing process uses a dual-laser system working in tandem. The dual-laser system includes a grooving laser and a dicing laser. Specifically, the stage holds the solar cell, the grooving laser creates dicing grooves at the front and rear ends of the solar cell that coincide with the target dicing line, and the dicing laser heats the solar cell along the target dicing line while simultaneously spraying a cooling medium onto the solar cell, causing the solar cell to slit.

[0003] like Figure 1 As shown, taking the dicing of a whole solar cell 10 into three slices as an example, the drawbacks of the existing dicing process are illustrated. When the solar cell 10 is diced into three slices, since the target dicing line A is not located on the center line of the solar cell 10, the materials on both sides of the target dicing line A are not symmetrical. This results in uneven thermal stress in the areas on both sides of the target dicing line after heating, causing the final actual dicing line B to bend away from the center line of the solar cell, forming an arc-shaped actual dicing line B.

[0004] Furthermore, when the battery cell is placed on the support platform 20, the support platform 20 adsorbs the middle part of the battery cell 10 but does not adsorb the two sides of the battery cell 10, thereby further increasing the stress difference on both sides of the target split line A, causing the actual split line B to deviate from the target split line A by a further increase in curvature.

[0005] After the solar cell 10 splits along the arc-shaped actual split line B, the edges of each segment have obvious curvature, which will affect the quality of the photovoltaic module in the future. Summary of the Invention

[0006] To address the aforementioned technical problems, the first aspect of this application provides a laser scribing method, the specific technical solution of which is as follows:

[0007] A laser scribing method, comprising:

[0008] A slotted laser, a slicing laser, and a polarization correction laser are provided, wherein the slotted laser is arranged in front of the slicing laser, and the polarization correction laser is arranged on the side of the slicing laser.

[0009] The solar cell is controlled to move below the grooving laser, the dicing laser, and the correction laser. The grooving laser scans the front and rear ends of the solar cell along the target dicing line to create grooves, while the dicing laser scans the solar cell along the target dicing line to dice it. During the dicing process:

[0010] When the spot of the shard laser is scanning the first or last segment of the target split line, the correction laser is turned off.

[0011] When the spot of the shard laser scans the middle section of the target split line, the correction laser is turned on so that the spot of the correction laser falls on the stress compensation side of the middle section of the target split line. The stress compensation side is the side with less stress and scans synchronously with the spot of the shard laser.

[0012] Alternatively, during the entire scanning process of the split laser, the correction laser scans the cell at the stress compensation side of the target split line. The stress compensation side is the side with less stress, and the power of the correction laser is output according to the preset power change curve.

[0013] The laser scribing method provided in this application includes a correction laser mounted on the side of the slicing laser. When the slicing laser scans the middle section of the target slicing line, the correction laser performs a heated scan to compensate for the stress in the middle section of the target slicing line. Alternatively, throughout the entire scanning process of the slicing laser, the correction laser performs a heated scan to compensate for the stress in the target slicing line according to a preset power change curve.

[0014] The heat generated during the scanning process by the polarization laser can compensate for the stress on the stress compensation side, so that the stress on both sides of the middle section or the entire section of the target split line tends to be balanced, thereby reducing the offset between the actual split line formed after splitting and the target split line, and improving the dicing quality.

[0015] In addition, a grooving laser is set on the front side of the splitting laser. The grooving laser can process grooves at both ends of the target splitting line, thereby ensuring that the cell can split smoothly after cooling.

[0016] In some embodiments, the distance between the spot of the polarization correction laser on the solar cell and the spot of the slicing laser on the solar cell is 0.1 mm–10 mm.

[0017] When the distance between the polarization-correcting laser spot and the slicing laser spot on the solar cell is too small, their spots will merge, effectively increasing the power of the slicing laser. The result is that the actual splitting line remains a large arc-shaped structure, deviating from the target splitting line. Conversely, when the distance between the polarization-correcting laser spot and the slicing laser spot is too large, the polarization-correcting laser spot will move far away from the target splitting line, ultimately failing to compensate for stress on the side.

[0018] By setting the spacing between the spot of the polarization correction laser on the solar cell and the spot of the dicing laser on the solar cell to 0.1mm–10mm, it can be ensured that the polarization correction laser can produce the predetermined polarization correction effect.

[0019] In some embodiments, the power of the shard laser is 100W–300W, and the power of the polarization correction laser is 10W–100W.

[0020] The power of the cleaving laser is set to 100W–300W. This ensures, on the one hand, that the laser spot can rapidly heat the target cleaving line, generating sufficient thermal stress along the cleaving line to ensure the cell can crack smoothly upon cooling. On the other hand, it prevents excessive temperature from damaging the internal structure of the cell, causing microcracks to deviate from the target cleaving line, or causing material melting. The power of the correction laser is set to 10W–100W, so that the correction laser only provides fine-tuning heating on the stress compensation side, rather than dominating the cleaving process.

[0021] In some embodiments, the shard laser is a near-infrared laser, and the polarization correction laser is a near-infrared laser, a blue laser, or a green laser.

[0022] The cleaving laser uses near-infrared laser, which allows the laser spot generated by the cleaving laser to penetrate into the interior of the solar cell, forming a deep temperature gradient at the target cleaving line, exciting sufficient stress to achieve cleaving, and avoiding surface overheating damage.

[0023] The polarization correction laser also employs a near-infrared laser, which can generate a similar heating effect on the stress compensation side, thereby balancing the stress in the depth direction. The polarization correction laser uses a blue or green laser to ensure that fine-tuning heating is provided to the stress compensation side while avoiding thermal damage to the internal structure of the cell on the stress compensation side.

[0024] In some embodiments, the length of the middle segment of the target split line accounts for 1 / 4 to 1 / 2 of the total length of the target split line, and the lengths of the first and last segments of the target split line are equal.

[0025] By controlling the correction laser to perform stress compensation on the middle section of the target split line from 1 / 4 to 1 / 2, segmented control of the correction laser can be easily implemented, and the predetermined correction effect can be ensured.

[0026] In some embodiments, the spot of the slicing laser is an elliptical spot with its major axis coinciding with the target splitting line, or the spot of the slicing laser is a circular spot; the spot of the polarization correction laser is an elliptical spot with its major axis parallel to the target splitting line, or the spot of the polarization correction laser is a circular spot.

[0027] In some embodiments, before controlling the dicing laser to dice the solar cell along the target dicing line, the laser dicing method further includes: calibrating the power of the correction laser so that the offset between the actual dicing line formed by the dicing and the target dicing line is less than a predetermined offset threshold.

[0028] The power of the correction laser is calibrated before the actual dicing process, which allows for accurate setting of the laser power and ensures that the offset between the actual dicing line and the target dicing line is below the offset threshold.

[0029] In some embodiments, calibrating the power of the polarization correction laser includes:

[0030] Set the power of the polarization correction laser to an initial low value;

[0031] After performing a cleaving operation on the calibration cell, measure the maximum offset between the actual cleaving line and the target cleaving line on the calibration cell.

[0032] If the maximum offset is greater than the offset threshold, the power of the polarization correction laser is increased by a predetermined step size, and the dicing and measurement process is repeated.

[0033] If the maximum offset is less than or equal to the offset threshold, the current power of the polarization correction laser is determined as the calibrated power.

[0034] A simple power calibration strategy is provided, which progressively increases the power of the polarization correction laser in predetermined steps until a suitable polarization correction laser power is found.

[0035] In some embodiments, before controlling the dicing laser to dice the solar cell along the target dicing line, the laser dicing method further includes determining a stress compensation side; wherein determining the stress compensation side includes:

[0036] Turn off the polarization correction laser and turn on the sharding laser;

[0037] The split laser is controlled to scan the test cell along the target split line to obtain a reference split line with an arc.

[0038] The side of the target split line furthest from the reference split line is taken as the stress compensation side.

[0039] By implementing the stress compensation side determination step, we can ensure that the stress compensation side can be accurately determined.

[0040] This application also provides a laser scribing apparatus for implementing the laser scribing method described in any of the above claims, comprising:

[0041] A support platform, used to support and adsorb battery cells;

[0042] A platform drive mechanism, the drive end of which is connected to the carrier platform, is configured to drive the carrier platform to move along a first direction;

[0043] The shard laser is located above the support stage;

[0044] The slotted laser is located above the support platform and positioned directly in front of the dicing laser;

[0045] The correction laser is located above the support stage and arranged on the side of the slicing laser;

[0046] The controller is configured to activate the polarization correction laser when the slit laser scans the middle section of the target split line; or to control the power of the polarization correction laser to output according to a preset power change curve throughout the entire scanning process of the slit laser.

[0047] The laser scribing device provided in this application is used to scribing the battery cell. The heat generated by the correction laser during the heating and scanning process can compensate for the stress on the stress compensation side, so that the stress on both sides of the middle section or the whole section of the target split line tends to be balanced, thereby reducing the offset between the actual split line formed after slicing and the target split line and improving the scribing quality. Attached Figure Description

[0048] Figure 1 This is a schematic diagram illustrating the scribing effect of the existing laser scribing process in a three-part embodiment;

[0049] Figure 2 This is a schematic diagram illustrating the scribing effect of the laser scribing method of this application in a three-slice embodiment;

[0050] Figure 3 The stress compensation side is determined by the laser scribing method of this application in the two-segment embodiment. Detailed Implementation

[0051] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that implementations of the application described herein can be implemented, for example, in sequences other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0053] This application provides a laser scribing method that can reduce the offset between the actual split line formed after slicing and the target split line, thereby improving the scribing quality.

[0054] Still using the three-point film as an example, combined with Figure 2 As shown, the laser scribing method of this application includes:

[0055] A slotting laser 1, a slicing laser 2, and a polarization correction laser 3 are provided, wherein the slotting laser 1 is arranged in front of the slicing laser 2, and the polarization correction laser 3 is arranged on the side of the slicing laser.

[0056] The control cell 10 moves below the grooving laser 1, the splitting laser 2, and the correction laser 3. The grooving laser 1 scans the front and rear ends of the cell along the target splitting line A to create a grooving groove 4, while the splitting laser 2 scans the cell 10 along the target splitting line A to split it.

[0057] It should be noted here that the slotting laser 1 is positioned directly in front of the dicing laser 2, while the correction laser 3 is positioned to the side of the dicing laser, relative to the direction of movement of the solar cell (e.g., ...). Figure 2 In the X direction, the grooving laser 1 and the dicing laser 2 are spaced apart along the moving direction of the solar cell, with the grooving laser 1 located in front of the dicing laser 2. This allows the grooving laser 1 to irradiate the solar cell 10 before the dicing laser 2, thus achieving pre-grooving. The correction laser 3 and the dicing laser 2 are positioned along a second direction perpendicular to the moving direction of the solar cell (e.g., in the X direction). Figure 2 (Interval setting in the Y direction)

[0058] In one embodiment, during the dicing process, when the spot of the dicing laser 2 scans the first or last segment of the target dicing line A, the polarization correction laser 3 is turned off. When the spot of the dicing laser 2 scans the middle segment of the target dicing line A, the polarization correction laser 3 is turned on, causing the spot of the polarization correction laser 3 to fall on the stress compensation side D of the middle segment of the target dicing line A. The stress compensation side D is the side with lower stress, and it scans synchronously with the spot of the dicing laser 2.

[0059] For example, Figure 2 In the three-cell embodiment shown, for the target split line A near the first side edge (e.g., the left side edge) of the cell 10, the stress compensation side D is the second side (e.g., the right side) of the target split line A. Conversely, for the target split line A near the second side edge (e.g., the right side edge) of the cell 10, the stress compensation side D is the first side (e.g., the left side) of the target split line A.

[0060] In another embodiment, during the entire process of the cleaving laser 2 scanning the target cleaving line A, the polarization correction laser 3 scans the solar cell 10 at the stress compensation side D of the target cleaving line A. That is, the polarization correction laser 3 remains on throughout the entire process of the cleaving laser 2 scanning the target cleaving line A. Similarly, the stress compensation side D is the side with lower stress. The power of the polarization correction laser 3 is output according to a preset power variation curve.

[0061] For example, the power of the polarization corrector laser 3 gradually increases from a lower first power to a higher second power, and then gradually decreases from the second power back to the first power. The first power occurs at both ends of the target split line A when the slit laser 2 scans, while the second power occurs at the middle of the target split line A. Alternatively, when the slit laser 2 scans the first or last segment of the target split line A, the power of the polarization corrector laser 3 is set to a lower first power; when the slit laser 2 scans the middle segment of the target split line A, the power of the polarization corrector laser 3 is set to a higher second power. The specific values ​​of the first and second powers can be set according to factors such as the power of the slit laser 2.

[0062] The laser scribing method provided in this application includes a correction laser 3 disposed on the side of the slicing laser 2. When the slicing laser 2 scans the middle section of the target slicing line A, the correction laser 3 performs a heated scan to compensate for the stress in the middle section of the target slicing line A. Alternatively, during the entire scanning process of the slicing laser 2, the correction laser 3 performs a heated scan on the stress compensation side D of the target slicing line A according to a preset power change curve.

[0063] The heat generated by the polarization correction laser 3 during the heating and scanning process can compensate for the stress on the stress compensation side D, so that the stress on both sides of the middle section or the entire section of the target split line A tends to be balanced, thereby reducing the offset between the actual split line B formed after splitting and the target split line A (which can be characterized by the maximum offset at the middle position), and improving the dicing quality.

[0064] In addition, since a slotting laser 1 is provided on the front side of the splitting laser 2, the slotting laser 1 can process the cleaving grooves 4 at both ends of the target splitting line A, thereby ensuring that the solar cell can be successfully split after being cooled (the solar cell is sprayed with cooling medium).

[0065] The splitting process is essentially a laser stress-induced directional fracture. The target of the correction laser 3 in this application is not simply to heat the solar cell, but to dynamically compensate for the stress on the stress compensation side by generating an asymmetric temperature field on one side (stress compensation side) of the target splitting line A, thereby reducing the stress difference on both sides of the target splitting line A.

[0066] Optionally, the length of the middle segment of the target split line A is 1 / 4 to 1 / 2 of the total length of the target split line A, and the lengths of the first and last segments of the target split line are equal. This setting allows for convenient segmented control of the polarization correction laser 3 and ensures that the polarization correction laser 3 can produce the predetermined polarization correction effect.

[0067] Optionally, the distance between the spot of the polarization-correcting laser 3 on the solar cell 10 and the spot of the slicing laser 2 on the solar cell is 0.1mm–10mm. In specific embodiments, the distance between the spot of the polarization-correcting laser 3 on the solar cell 10 and the spot of the slicing laser 2 on the solar cell 10 can be set to 0.1mm, 0.2mm, 0.3mm, ..., 8mm, 9mm, 10mm, etc., according to the spot size, power, and other parameters of the polarization-correcting laser 3 and the slicing laser 2, respectively.

[0068] When the distance between the spot of the polarization correction laser 3 on the solar cell 10 and the spot of the slicing laser 2 on the solar cell 10 is too small (<0.1mm), the spot of the polarization correction laser 3 and the spot of the slicing laser 2 will merge, which is equivalent to simply increasing the power of the slicing laser 2. The final result is that the actual splitting line B is still an arc structure with too large an arc, and the actual splitting line B deviates from the target splitting line A as a whole.

[0069] When the distance between the spot of the polarization correction laser 3 on the solar cell 10 and the spot of the split laser 2 on the solar cell 10 is too large, the spot of the polarization correction laser 3 is far away from the target splitting line A, and ultimately cannot play the role of compensating for the stress on the stress compensation side D.

[0070] By setting the distance between the spot of the polarization correction laser 3 on the solar cell and the spot of the cleaving laser 2 on the solar cell 10 to 0.1mm–10mm, it can be ensured that the polarization correction laser 3 can produce the predetermined polarization correction effect.

[0071] Optionally, the power of the slicing laser 2 is 100W–300W, and the power of the polarization correction laser 3 is 10W–100W. Specifically, the power of the slicing laser 2 can be set to 100W, 110W, ..., 200W, 300W, etc., and the power of the polarization correction laser 3 can be set to 10W, 20W, ..., 90W, 100W, etc., depending on factors such as the spot size of the polarization correction laser 3 and the slicing laser 2, the thickness and material of the solar cell 10.

[0072] The power of the slicing laser 2 is set to 100W–300W. On the one hand, this ensures that the light spot generated by the slicing laser 2 can quickly heat the target splitting line A, so that the corresponding area of ​​the solar cell 10 generates sufficient thermal stress, and ultimately ensures that the solar cell 10 can crack smoothly after cooling. On the other hand, it can avoid damage to the internal structure of the solar cell (such as the PN junction), the propagation of microcracks deviating from the target splitting line A, or the melting of materials caused by excessively high temperature.

[0073] The power of the polarization correction laser 3 is set to 10W–100W, so that the polarization correction laser only provides fine-tuning heating on the stress compensation side D, rather than dominating the cleavage process.

[0074] For the segmented control strategy in the first embodiment described above, for example, the power of the shard laser 2 can be set to 100W, while the power of the polarization correction laser 3 can be set to a constant 10W. Alternatively, the power of the shard laser 2 can be set to 300W, while the power of the polarization correction laser 3 can be set to a constant 100W.

[0075] Regarding the control strategy of keeping the polarization correction laser 3 running continuously in the second implementation described above, for example, the power of the shard laser 2 can be set to 100W, while the power of the polarization correction laser 3 can be gradually increased from 10W to 30W, and then gradually decreased from 30W to 10W. Alternatively, the power of the shard laser 2 can be set to 300W, while the power of the polarization correction laser 3 can be gradually increased from 30W to 100W, and then gradually decreased from 100W to 30W.

[0076] Optionally, the shard laser 2 is a near-infrared laser, and the polarization correction laser 3 is a near-infrared laser, a blue laser, or a green laser.

[0077] The cleaving laser 2 uses a near-infrared laser, which allows the light spot generated by the cleaving laser 2 to penetrate into the interior of the solar cell 10, forming a deep temperature gradient at the target cleaving line A, exciting sufficient stress to achieve cleaving, and avoiding overheating damage to the surface of the solar cell 10.

[0078] The polarization correction laser 3 also employs a near-infrared laser, which can generate a similar heating effect on the stress compensation side D, thereby balancing the stress in the depth direction. However, if the polarization correction laser 3 uses a blue or green laser, it can ensure that fine-tuning heating is provided on the stress compensation side D while avoiding thermal damage to the internal structure (such as the PN junction) of the battery cell 10 on the stress compensation side D.

[0079] Optionally, the light spot of the slicing laser 2 is an elliptical light spot, with its major axis coinciding with the target splitting line A. Of course, the light spot of the slicing laser 2 can also be a circular light spot.

[0080] Similarly, optionally, the spot of the polarization-correcting laser 3 can be an elliptical spot, with its major axis parallel to the target splitting line A. Of course, the spot of the polarization-correcting laser 3 can also be a circular spot.

[0081] Optionally, before controlling the dicing laser 2 to dice the solar cell 10 along the target dicing line A, the laser dicing method in this embodiment further includes:

[0082] The power of the polarization correction laser 3 is calibrated so that the offset between the actual split line B formed by the cleavage and the target split line A is less than a predetermined offset threshold.

[0083] Before the formal dicing, the power of the correction laser 3 is calibrated to ensure precise setting of its power. This guarantees that the offset between the actual dicing line B and the target dicing line A formed during the formal dicing of the solar cell 10 is below the offset threshold. Alternatively, in some embodiments, the power of the correction laser 3 can be determined empirically. For example, when the user has a high tolerance for the offset between the actual dicing line B and the target dicing line A (i.e., a large offset threshold), the power of the correction laser 3 can be directly set to 10% of the power of the dicing laser 2, thus ensuring that the offset between the actual dicing line B and the target dicing line A is less than the offset threshold.

[0084] Optionally, the power calibration of the polarization correction laser 3 in this application includes:

[0085] Set the power of the polarization correction laser 3 to an initial low value.

[0086] After the cleaving process is performed, the maximum offset between the actual cleaving line B and the target cleaving line A on the solar cell 10 is measured.

[0087] If the maximum offset is greater than the offset threshold, the power of the correction laser 3 is increased by a predetermined step size, and the dicing and measurement process is repeated; if the maximum offset is less than or equal to the offset threshold, the current power of the correction laser 3 is determined as the calibrated power.

[0088] The initial low value and predetermined step size of the correction laser 3 can be set according to factors such as the power of the dicing laser 2, the thickness and material of the solar cell 10, etc., while the offset threshold can be selected and set according to the specific requirements for the dicing quality. For example, in one embodiment of this application, the power of the dicing laser 2 is 100W. The initial low value of the correction laser 3 is set to 10W, the predetermined step size is set to 1W, and the offset threshold is set to 0.1mm.

[0089] The calibration process for the power of the polarization corrector laser 3 is as follows:

[0090] The first calibration cell 10 is provided. Of course, the calibration cell 10 is the same as the cell 10 to be diced, or is directly selected from the current batch of cells 10 to be diced.

[0091] The power of the correction laser 3 is set to 10W, and the first calibration cell 10 is split. After splitting, the maximum offset between the actual splitting line B and the target splitting line A on the cell 10 is measured (generally occurring at the middle position of the target splitting line A).

[0092] If the maximum offset is less than or equal to 0.1mm, the power of the correction laser 3 is set to 10W, and the power calibration process ends.

[0093] Otherwise, set the power of the polarization correction laser 3 to 11W.

[0094] A second calibration cell is provided, and the second calibration cell is cleaved. After cleaving, the maximum offset between the actual cleavage line B and the target cleavage line A on the cell 10 is measured.

[0095] If the maximum offset is less than or equal to 0.1mm, the power of the correction laser 3 is set to 11W, and the power calibration process ends.

[0096] Otherwise, set the power of the polarization correction laser 3 to 12W and repeat the above dicing and measurement process until the maximum offset is less than or equal to 0.1mm, then determine the power of the polarization correction laser 3.

[0097] Optionally, before controlling the dicing laser 2 to dice the battery cell 10 along the target dicing line A, the laser dicing method in this embodiment further includes: determining the stress compensation side D.

[0098] The specific process for determining the stress compensation side D is as follows:

[0099] Provide test cells, which are the same as the cells to be diced, or are directly selected from the current batch of cells to be diced.

[0100] Turn off the correction laser 3 and turn on the cleaving laser 2. Of course, the cleaving laser 1 must remain on when the front and rear ends of the solar cell pass under the cleaving laser 1, and the cleaving laser 1 must be turned off when other parts of the solar cell pass under the cleaving laser 1.

[0101] The split laser 2 is controlled to scan and split the test cell along the target split line A to obtain a reference split line with an arc.

[0102] The side of the target split line A that is far from the reference split line is taken as the stress compensation side D.

[0103] Before formally cleaving the solar cells, determining the stress compensation side D through the above steps ensures that the stress compensation side D is correctly selected. Of course, in some embodiments, the stress compensation side D can also be determined empirically. For example... Figure 1 and Figure 2 In the three-cell embodiment shown, the stress compensation side D is the side of the target split line A facing the center line of the cell 10. For example, Figure 3 In the two-segment embodiment shown, the target split line A coincides with the center line of the battery cell 10, the support platform 20 adsorbs half of the battery cell 10 (such as the right half), and the stress compensation side D is the side of the target split line A closer to the support platform 20 (such as the right side).

[0104] This application also provides a laser scribing apparatus for implementing the laser scribing method provided in the embodiments of this application. (Referring to the references...) Figure 2 As shown, the laser scribing apparatus of this application includes:

[0105] The support platform 20 is used to support and adsorb the battery cells 10.

[0106] The platform drive mechanism is connected to the carrier platform 20 at its drive end. The platform drive mechanism is configured to drive the carrier platform 20 to move along a first direction (such as the X direction).

[0107] The shard laser 2 is located above the support stage 20.

[0108] The slotting laser 1 is located above the support platform 20 and is positioned directly in front of the dicing laser 2.

[0109] The correction laser 3 is located above the support stage 20 and arranged on the side of the shard laser 2.

[0110] The controller is configured to turn on the correction laser 3 when the slit laser 2 scans the middle section of the target split line A, or to control the power of the correction laser 3 to be output according to a preset power change curve throughout the scanning process of the slit laser 2.

[0111] For further details regarding the laser scribing device of this application, please refer to the relevant descriptions in the preceding method embodiments, which will not be repeated here.

[0112] The laser scribing device provided in this application is used to scribing the battery cell. The heat generated by the correction laser during the heating and scanning process can compensate for the stress on the stress compensation side D, so that the stress on both sides of the middle section or the entire section of the target split line A tends to be balanced, thereby reducing the offset between the actual split line B formed after slicing and the target split line A, and improving the scribing quality.

[0113] The platform drive mechanism can adopt various existing linear drive modules, as long as they can drive the support platform 20 to move stably along the first direction.

[0114] The foregoing has provided a sufficiently detailed and specific description of this application. Those skilled in the art should understand that the descriptions in the embodiments are merely exemplary, and all changes made without departing from the true spirit and scope of this application should fall within the protection scope of this application. The scope of protection claimed in this application is defined by the claims, and not by the above descriptions in the embodiments.

Claims

1. A laser scribing method, characterized in that, The laser scribing method includes: A slotted laser, a slit laser, and a polarization correction laser are provided, wherein the slotted laser is arranged on the front side of the slit laser, and the polarization correction laser is arranged on the side of the slit laser. The solar cell is controlled to move below the grooving laser, the dicing laser, and the correction laser. The grooving laser scans the front and rear ends of the solar cell along the target dicing line to create grooves, while the dicing laser scans the solar cell along the target dicing line to dice it. During the dicing process: When the spot of the slicing laser scans the first or last segment of the target split line, the correction laser is turned off. When the spot of the slicing laser scans the middle section of the target split line, the correction laser is turned on, so that the spot of the correction laser falls on the stress compensation side of the middle section of the target split line, which is the side with less stress, and scans synchronously with the spot of the slicing laser. Alternatively, during the entire scanning process of the split laser, the correction laser scans the solar cell at the stress compensation side of the target split line, where the stress compensation side is the side with lower stress, and the power of the correction laser is output according to a preset power change curve.

2. The laser scribing method as described in claim 1, characterized in that: The distance between the spot of the polarization correction laser on the solar cell and the spot of the slit laser on the solar cell is 0.1 mm–10 mm.

3. The laser scribing method as described in claim 1, characterized in that, The power of the shard laser is 100W–300W, and the power of the polarization correction laser is 10W–100W.

4. The laser scribing method as described in claim 1, characterized in that, The slit laser is a near-infrared laser, and the polarization correction laser is a near-infrared laser, a blue laser, or a green laser.

5. The laser scribing method as described in claim 1, characterized in that: The length of the middle segment of the target split line is 1 / 4 to 1 / 2 of the total length of the target split line, and the lengths of the first and last segments of the target split line are equal.

6. The laser scribing method as described in claim 1, characterized in that: The laser spot of the slicing laser is an elliptical spot, the major axis of which coincides with the target splitting line, or the laser spot of the slicing laser is a circular spot; The laser beam of the polarization correction laser is an elliptical beam with its major axis parallel to the target splitting line, or the laser beam of the polarization correction laser is a circular beam.

7. The laser scribing method as described in claim 1, characterized in that, Before controlling the dicing laser to dice the solar cell along the target dicing line, the laser dicing method further includes: The power of the correction laser is calibrated so that the offset between the actual split line formed by the cleavage and the target split line is less than a predetermined offset threshold.

8. The laser scribing method as described in claim 7, characterized in that, The calibration of the power of the polarization correction laser includes: Set the power of the polarization correction laser to an initial low value; After performing a cleaving operation on the calibration cell, measure the maximum offset between the actual cleaving line and the target cleaving line on the calibration cell. If the maximum offset is greater than the offset threshold, the power of the correction laser is increased by a predetermined step size, and the dicing and measurement process is repeated. If the maximum offset is less than or equal to the offset threshold, then the current power of the polarization correction laser is determined to be the calibrated power.

9. The laser scribing method as described in claim 1, characterized in that, Before controlling the dicing laser to dic the solar cell along the target dicing line, the laser dicing method further includes determining the stress compensation side; The determination of the stress compensation side includes: Turn off the polarization correction laser and turn on the sharding laser; The laser is controlled to scan the test cell along the target splitting line to obtain a reference splitting line with an arc. The side of the target split line that is furthest from the reference split line is taken as the stress compensation side.

10. A laser scribing apparatus for implementing the laser scribing method according to any one of claims 1-9, characterized in that, The laser scribing device includes: A support platform, used to support and adsorb battery cells; A platform drive mechanism, the drive end of which is connected to the support platform, is configured to drive the support platform to move along a first direction; A shard laser is located above the support platform; A slotted laser is located above the support platform and arranged directly in front of the dicing laser; A polarization correction laser is located above the support platform and arranged on the side of the slit laser; The controller is configured to turn on the correction laser when the slit laser scans the middle section of the target split line; or to control the power of the correction laser to be output according to a preset power change curve throughout the entire scanning process of the slit laser.

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