Metallization sintering system and sintering method for battery piece

Abstract

The invention relates to the technical field of solar cells, in particular to a metallization sintering system and method for a cell piece. The metallization sintering system of the battery piece comprises a laser, power supply equipment, image shooting equipment and control equipment, the laser, the power supply equipment and the image shooting equipment are in communication connection with the control equipment; the control device determines a first laser scanning path corresponding to the P-area auxiliary gate electrode and a second laser scanning path corresponding to the N-area auxiliary gate electrode; a first target sintering parameter corresponding to the first laser scanning path is different from a second target sintering parameter corresponding to the second laser scanning path; the target sintering parameters comprise deflection voltage applied to the battery piece by the power supply equipment and laser output power of a laser. According to the technical scheme, the contact resistance between the metal electrode and the semiconductor can be reduced, and the photoelectric conversion efficiency of the TBC battery piece can be improved to a greater extent.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more particularly to a metallization sintering system and sintering method for solar cells. Background Art

[0002] The contact resistance between the metal electrodes on the surface of a solar cell and the silicon substrate (semiconductor) has a significant impact on the cell's conversion efficiency; the lower the contact resistance, the higher the conversion efficiency. In the metallization process, metal grid lines, i.e., metal electrodes, are printed on the back and front of the cell using screen printing technology. The contact resistance between the metal electrodes and the semiconductor is relatively high.

[0003] Currently, there are two main ways to reduce the contact resistance between metal electrodes and semiconductors: First, traditional sintering furnaces are used to sinter metal electrodes at high temperatures. However, due to the instability of temperature caused by airflow, it is difficult to form a better ohmic contact, and excessively high temperatures can easily cause cell deformation and high breakage rate. Second, the Laser Enhanced Contact Optimization (LECO) process is used. This process uses a high-intensity laser to irradiate the cell to excite charge carriers and separates the charge carriers under an applied deflection voltage to form a local current, which triggers sintering and reduces the contact resistance between metal electrodes and semiconductors.

[0004] For tunnel oxide passivated contact (TBC) solar cells, both the P-region (hole-type semiconductor region) and N-region (electron-type semiconductor region) are located on the back side of the TBC cell. When using the LECO process to sinter the metal electrodes on the back side of the TBC cell, the P / N regions are scanned under the same laser parameters, resulting in the P / N regions being sintered at the same temperature. However, the polysilicon layer thickness corresponding to the P / N regions on the back side of the cell varies. Metallizing P / N regions with different polysilicon layer thicknesses under the same laser parameters cannot fully utilize the LECO process to reduce the contact resistance of the metal electrodes within the P / N regions, thus failing to maximize the efficiency improvement of the TBC cell achieved by the LECO process. Summary of the Invention

[0005] To solve the above-mentioned technical problems, or at least partially solve them, the present invention provides a metallization sintering system and sintering method for battery cells, which helps to reduce the contact resistance between the metal electrode and the semiconductor, and can maximize the photoelectric conversion efficiency of TBC battery cells.

[0006] In a first aspect, the present invention provides a metallization sintering system for battery cells, comprising:

[0007] Lasers, power supply equipment, imaging equipment, and control equipment;

[0008] The laser, the power supply, and the image capturing device are all communicatively connected to the control device; the back of the battery cell includes parallel and alternately arranged P-regions and N-regions, and pre-cured sub-gate electrodes are formed in both the P-regions and the N-regions.

[0009] The image capturing device is used to capture a back image of the battery cell and transmit the back image to the control device; the control device determines the first laser scanning path corresponding to the P-region sub-gate electrode and the second laser scanning path corresponding to the N-region sub-gate electrode based on the back image, and controls the laser and the power supply device to perform metallization sintering of the battery cell according to the target sintering parameters based on the laser scanning paths;

[0010] The first target sintering parameters corresponding to the first laser scanning path are different from the second target sintering parameters corresponding to the second laser scanning path; the target sintering parameters include the deflection voltage applied by the power supply device to the battery cell and the laser output power of the laser.

[0011] In some embodiments, both the P region and the N region are formed with pre-cured main gate electrodes; the P region main gate electrode and the P region sub-gate electrode are arranged intersectingly, and the N region main gate electrode and the N region sub-gate electrode are arranged intersectingly.

[0012] The positive terminal of the power supply device is connected to the N-region main grid electrode, and the negative terminal of the power supply device is connected to the P-region main grid electrode to apply a deflection voltage to the solar cell.

[0013] In some embodiments, the metallization sintering system for the solar cell further includes:

[0014] The probe array assembly includes a positive probe array and a negative probe array. The positive terminal of the power supply device is connected to the N-region main gate electrode through the positive probe array, and the negative terminal of the power supply device is connected to the P-region main gate electrode through the negative probe array.

[0015] In some embodiments, the back surface of the battery cell includes a first region, a second region, a third region, and a fourth region arranged sequentially, each region including parallel and alternately arranged P-regions and N-regions;

[0016] The first region and the second region are electrically connected to the main gate electrodes arranged in the same extending direction, the third region and the fourth region are electrically connected to the main gate electrodes arranged in the same extending direction, and the second region and the third region are electrically disconnected from the main gate electrodes arranged in the same extending direction; the probe array assembly includes a pair;

[0017] When one probe array assembly is connected to the main gate electrode of the first region and another probe array assembly is connected to the main gate electrode of the fourth region, the laser performs laser scanning on the second region and the third region; when one probe array assembly is connected to the main gate electrode of the second region and another probe array assembly is connected to the main gate electrode of the third region, the laser performs laser scanning on the first region and the fourth region.

[0018] In some embodiments, the stage includes an insulating platform, with the front side of the battery cell facing the insulating platform.

[0019] In some embodiments, the deflection voltage corresponding to the first laser scanning path is greater than the deflection voltage corresponding to the second laser scanning path.

[0020] In some embodiments, the laser output power corresponding to the first laser scanning path is greater than the laser output power corresponding to the second laser scanning path.

[0021] In some embodiments, the laser emission frequency corresponding to the first laser scanning path is the same as the laser emission frequency corresponding to the second laser scanning path.

[0022] Secondly, embodiments of the present invention also provide a method for metallizing and sintering a battery cell, implemented using the battery cell metallization and sintering system described in the first aspect; the method for metallizing and sintering the battery cell includes:

[0023] Obtain a back image of the solar cell; the back of the solar cell includes parallel and alternately arranged P-regions and N-regions, and both the P-regions and the N-regions have pre-cured sub-gate electrodes formed thereon;

[0024] The first laser scanning path corresponding to the sub-gate electrode in the P region and the second laser scanning path corresponding to the sub-gate electrode in the N region are determined by the back image.

[0025] Based on the laser scanning path, the laser and the power supply device are controlled to perform metallization sintering of the battery cell according to the target sintering parameters;

[0026] The first target sintering parameter corresponding to the first laser scanning path is different from the second target sintering parameter corresponding to the second laser scanning path; the target sintering parameter includes the deflection voltage applied by the power supply device to the battery cell and the laser output power emitted by the laser.

[0027] In some embodiments, determining the first laser scanning path corresponding to the P-region sub-gate electrode and the second laser scanning path corresponding to the N-region sub-gate electrode using the back image includes:

[0028] Based on the back image, a first drawing pattern corresponding to the region where the sub-gate electrode of the P region is located and a second drawing pattern corresponding to the region where the sub-gate electrode of the N region is located are obtained.

[0029] The battery cell area corresponding to the first drawn pattern is used as the first laser scanning path, and the battery cell area corresponding to the second drawn pattern is used as the second laser scanning path.

[0030] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art:

[0031] The metallization sintering system provided in this invention, tailored to the unique structure of TBC solar cells, employs different target sintering parameters based on the different fabrication processes of the P / N regions on the back side of the cell, performing sintering separately. This avoids sintering the P / N regions at the same temperature, minimizing the contact resistance of the metal electrodes within the P / N regions. By sintering the metal electrodes within the P / N regions separately, the sintering temperatures of the two regions can be freely adjusted, which is beneficial for reducing the contact resistance of the metal electrodes and maximizing the photoelectric conversion efficiency of the TBC solar cell. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A structural block diagram of a metallization sintering system for a battery cell provided in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram illustrating an application scenario of a metallization sintering system for a battery cell provided in an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the structure of a battery cell provided in an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of another battery cell structure provided in an embodiment of the present invention;

[0038] Figure 5 This is a schematic flowchart of a metallization sintering method for a battery cell provided in an embodiment of the present invention.

[0039] Among them, 1. Laser; 2. Power supply equipment; 3. Stage; 4. Positive probe array; 5. Negative probe array; 6. Battery cell; 7. Image capturing equipment; 8. Control equipment; 9. P-region; 10. N-region; 11. Sub-gate electrode; 111. P-region sub-gate electrode; 112. N-region sub-gate electrode; 12. Main gate electrode; 121. P-region main gate electrode; 122. N-region main gate electrode; 13. Pad; 01. First region; 02. Second region; 03. Third region; 04. Fourth region. Detailed Implementation

[0040] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0041] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0042] The metallization sintering system provided in this invention, tailored to the unique structure of TBC solar cells, employs different target sintering parameters based on the different fabrication processes of the P / N regions on the back side of the cell, performing sintering separately. This avoids sintering the P / N regions at the same temperature, minimizing the contact resistance of the metal electrodes within the P / N regions. By sintering the metal electrodes within the P / N regions separately, the sintering temperatures of the two regions can be freely adjusted, which is beneficial for reducing the contact resistance of the metal electrodes and maximizing the photoelectric conversion efficiency of the TBC solar cell.

[0043] The metallization sintering system and method for battery cells provided in the embodiments of the present invention will be described exemplarily below with reference to the accompanying drawings.

[0044] Figure 1 This is a structural block diagram of a metallization sintering system for a battery cell provided in an embodiment of the present invention. Figure 2 This is a schematic diagram illustrating an application scenario of a metallization sintering system for battery cells provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of a battery cell provided in an embodiment of the present invention. Figures 1 to 3 As shown, the metallization sintering system for the solar cell includes: a laser 1, a power supply 2, an image capturing device 7, and a control device 8; the laser 1, the power supply 2, and the image capturing device 7 are all communicatively connected to the control device 8; the stage 3 is used to place the solar cell 6, and the back of the solar cell 6 includes parallel and alternately arranged P regions 9 and N regions 10, and both P regions 9 and N regions 10 are formed with pre-cured sub-gate electrodes 11;

[0045] Image capturing device 7 is used to capture the back image of battery cell 6 and transmit the back image to control device 8; control device 8 determines the first laser scanning path corresponding to P-region sub-gate electrode 11 and the second laser scanning path corresponding to N-region sub-gate electrode 11 based on the back image, and controls laser 1 and power supply device 2 to perform metallization sintering of battery cell 6 according to target sintering parameters based on the laser scanning path.

[0046] The target sintering parameters corresponding to the first laser scanning path are different from those corresponding to the second laser scanning path; the target sintering parameters include the deflection voltage applied by the power supply device 2 to the battery cell 6 and the laser output power of the laser 1.

[0047] The solar cell 6 can be a TBC solar cell. The back side of the solar cell 6 includes parallel alternating P-regions 9 and N-regions 10, both of which have pre-cured sub-grid electrodes 11 (metal electrodes). Specifically, this pre-curing refers to the production of the solar cell 6 with pre-cured metal electrodes using normal processes (wet process, high temperature, metallization), i.e., sintering in a low-temperature sintering furnace and drying in a drying oven to obtain the pre-cured metal electrode solar cell 6.

[0048] Specifically, in this embodiment of the invention, the battery cell 6 with pre-cured metal electrodes is further subjected to metallization sintering using the LECO process. Specifically, an image capturing device 7, such as but not limited to a camera, is used to photograph the back of the battery cell 6 and acquire the photographed image. Then, a control device 8 determines the positions of the P-region sub-gate electrode 111 and the N-region sub-gate electrode 112 based on the photographed image, thereby acquiring the first laser scanning path corresponding to the P-region sub-gate electrode 111 and the second laser scanning path corresponding to the N-region sub-gate electrode 112.

[0049] When the P-region sub-gate electrode 111 is metallized and sintered using the LECO process, the first target sintering parameters can be used to metallize and sinter the cell 6; when the N-region sub-gate electrode 112 is metallized and sintered using the LECO process, the second target sintering parameters are used to metallize and sinter the cell 6; wherein, the first target sintering parameters and the second target sintering parameters are different.

[0050] Therefore, depending on the fabrication process of the P / N region and the thickness of the polysilicon in the P / N region, as well as the paste used for printing the metal electrode grid lines, different target sintering parameters can be used for the P / N region to freely adjust the sintering temperature of the two regions, avoid co-sintering of the P / N regions at the same temperature, and achieve sintering temperatures adapted to the respective P / N regions. This can minimize the contact resistance between the metal electrode and the silicon substrate within the P / N region 10.

[0051] In addition, when sintering the metal electrodes in the P / N region, high temperature can be avoided from damaging the passivation layer of the non-metallic electrode region in the P / N region, thereby maximizing the protection of the passivation film layer of the non-metallic electrode region in the P / N region and ensuring that the passivation effect of the passivation layer is not reduced.

[0052] Specifically, both the first and second laser scanning paths are S-shaped. For example, as shown... Figure 3 As shown, P region 9 and N region 10 are arranged alternately in parallel along the first direction XX'. The sub-gate electrode 111 of P region is located in P region 9 and is arranged along the first direction XX'. The sub-gate electrode 112 of N region is located in N region 10 and is arranged along the first direction XX'. When sintering the P-region sub-gate electrode 111, the first direction XX' is used as the row direction. The laser beam scan starts from the sub-gate electrode of the first row of P-region 9 and sequentially scans the sub-gate electrodes of other rows of P-region 9. The laser beam scanning speed is 40-100 m / s; the energy density is 1000 W / cm²-30000 W / cm²; the laser beam spot is square, and a single spot is required to completely cover the width of the P-region sub-gate electrode 111. Similarly, when sintering the N-region sub-gate electrode 112, the first direction XX' is used as the row direction. The laser beam scan starts from the sub-gate electrode of the first row of N-region 10 and sequentially scans the sub-gate electrodes of other rows of N-region 10. The laser beam scanning speed is 40-100 m / s; the energy density is 1000 W / cm²-30000 W / cm²; the laser beam spot is square, and a single spot is required to completely cover the width of the N-region sub-gate electrode 112. Therefore, by using the "line scan" method, the sub-gate electrode 11 can be precisely laser sintered.

[0053] Therefore, the metallization sintering system for the solar cell provided in this embodiment of the invention, tailored to the unique structure of TBC solar cells, employs different target sintering parameters based on the different fabrication processes of the P / N regions on the back side of the solar cell, performing sintering separately. This avoids sintering the P / N regions at the same temperature, minimizing the contact resistance of the metal electrodes within the P / N regions. By sintering the metal electrodes within the P / N regions separately, the sintering temperatures of the two regions can be freely adjusted, which is beneficial for reducing the contact resistance of the metal electrodes and maximizing the photoelectric conversion efficiency of the TBC solar cell.

[0054] In some embodiments, such as Figures 1 to 3 As shown, both P region 9 and N region 10 have pre-cured main gate electrodes 12; the P region main gate electrode 121 and the P region sub-gate electrode 111 are arranged intersectingly, and the N region main gate electrode 122 and the N region sub-gate electrode 111 are arranged intersectingly.

[0055] The positive terminal A of the power supply device 2 is connected to the N-region main grid electrode 122, and the negative terminal B of the power supply device 2 is connected to the P-region main grid electrode 121 to apply a deflection voltage to the battery cell 6.

[0056] Specifically, if Figure 3 As shown, along the second direction YY', the P-region main gate electrode 121 and the N-region main gate electrode 122 are arranged alternately in parallel.

[0057] In this configuration, the positive terminal A of the power supply device 2 is connected to the N-region main grid electrode 122, and the negative terminal B of the power supply device 2 is connected to the P-region main grid electrode 121, thereby enabling the application of a deflection voltage to the solar cell 6. Simultaneously, while the deflection voltage is applied to the solar cell 6, the laser 1 emits a laser beam to irradiate the solar cell 6. The applied deflection voltage excites charge carriers, which then separate under the deflection voltage, forming a local current. The laser 1 then emits a laser beam to induce sintering of the metal electrodes, thereby reducing the contact resistance between the metal electrodes and the semiconductor.

[0058] In some embodiments, such as Figures 1 to 3 As shown, the metallization sintering system of the battery cell also includes a probe array assembly, which includes a positive probe array 4 and a negative probe array 5. The positive terminal A of the power supply device 2 is connected to the N-region main grid electrode 122 through the positive probe array 4, and the negative terminal B of the power supply device 2 is connected to the P-region main grid electrode 121 through the negative probe array 5.

[0059] The N-region main gate electrode 122 is provided with a pad 13, and the P-region main gate electrode 121 is also provided with a pad 13. The positive electrode probe array 4 is connected to the N-region main gate electrode 122 through the pad 13, and the negative electrode probe array 5 is connected to the P-region main gate electrode 121 through the pad 13. Thus, the power supply device 2 can apply a deflection voltage to the battery cell 6 using the probe array assembly.

[0060] In some embodiments, Figure 4 This is a schematic diagram of another battery cell structure provided in an embodiment of the present invention. Figures 1 to 4As shown, the back of the battery cell 6 includes a first region 0101, a second region 02, a third region 03, and a fourth region 04 arranged sequentially. Each region includes parallel and alternately arranged P-regions 9 and N-regions 10. The first region 01 and the second region 02 are electrically connected to the main grid electrodes 12 arranged in the same extending direction. The third region 03 and the fourth region 04 are electrically connected to the main grid electrodes 12 arranged in the same extending direction. The second region 02 and the third region 03 are electrically disconnected from the main grid electrodes 12 arranged in the same extending direction. The probe array assembly includes a pair. When one probe array assembly is connected to the main grid electrode 12 of the first region 01 and the other probe array assembly is connected to the main grid electrode 12 of the fourth region 04, the laser 1 performs laser scanning on the second region 02 and the third region 03. When one probe array assembly is connected to the main grid electrode 12 of the second region 02 and the other probe array assembly is connected to the main grid electrode 12 of the third region 03, the laser 1 performs laser scanning on the first region 01 and the fourth region 04.

[0061] Specifically, in this embodiment of the invention, the back surface of the battery is divided into a first region 01, a second region 02, a third region 03, and a fourth region 04. The first region 01 and the second region 02 are electrically connected between main grid electrodes 12 arranged in the same extending direction; the third region 03 and the fourth region 04 are electrically connected between main grid electrodes 12 arranged in the same extending direction; and the second region 02 and the third region 03 are electrically disconnected from the main grid electrodes 12 arranged in the same extending direction.

[0062] Therefore, by using one probe array assembly to contact the first region 01, a deflection voltage can be applied to the second region 02 simultaneously, and by using another probe array assembly to contact the fourth region 04, a deflection voltage can be applied to the third region 03 simultaneously. When the laser 1 scans the second region 02 and the third region 03, since the probe array assemblies are not located within these regions, interference from the probe array assemblies is avoided. This facilitates a thorough laser scan of the second region 02 and the third region 03, ensuring that all sub-gate electrodes 11 on the back of the solar cell 6 can be laser-induced sintered. If two probe array assemblies are placed in contact with the second region 02 and the third region 03, the laser 1 will experience probe array obstruction during laser scanning, resulting in incomplete laser scanning and potential damage to the probe array assemblies.

[0063] It should be noted that when laser 1 performs laser scanning on the second region 02 and the third region 03, it can first perform metallization sintering on the P-region sub-gate electrode locations of the second region 02 and the third region 03 according to the first target sintering parameters corresponding to the first laser scanning path, and then perform metallization sintering on the N-region sub-gate electrode locations of the second region 02 and the third region 03 according to the second target sintering parameters corresponding to the second laser scanning path; or, it can first perform metallization sintering on the N-region sub-gate electrode locations of the second region 02 and the third region 03 according to the second target sintering parameters corresponding to the second laser scanning path, and then perform metallization sintering on the P-region sub-gate electrode locations of the second region 02 and the third region 03 according to the first target sintering parameters corresponding to the first laser scanning path.

[0064] Similarly, by using one probe array assembly to contact the second region 02, a deflection voltage can be applied to the first region 01 simultaneously. Similarly, by using another probe array assembly to contact the third region 03, a deflection voltage can be applied to the fourth region 04 simultaneously. When the laser 1 performs laser scanning on the first region 01 and the fourth region 04, since the probe array assemblies are not located within these regions, interference from the probe array assemblies is avoided. This facilitates thorough laser scanning of the first region 01 and the fourth region 04, ensuring that all sub-gate electrodes 11 on the back of the solar cell 6 can be laser-induced sintered. If two probe array assemblies are placed in contact with the first region 01 and the fourth region 04, the probe arrays will block the laser scan, resulting in incomplete scanning and potential damage to the probe array assemblies.

[0065] It should be noted that when laser 1 performs laser scanning on the first region 01 and the fourth region 04, it can first perform metallization sintering on the P-region sub-gate electrode locations of the first region 01 and the fourth region 04 according to the first target sintering parameters corresponding to the first laser scanning path, and then perform metallization sintering on the N-region sub-gate electrode locations of the first region 01 and the fourth region 04 according to the second target sintering parameters corresponding to the second laser scanning path; or, it can first perform metallization sintering on the N-region sub-gate electrode locations of the first region 01 and the fourth region 04 according to the second target sintering parameters corresponding to the second laser scanning path, and then perform metallization sintering on the P-region sub-gate electrode locations of the first region 01 and the fourth region 04 according to the first target sintering parameters corresponding to the first laser scanning path.

[0066] In some embodiments, such as Figure 2 As shown, the stage 3 includes an insulating platform 31, with the front of the battery cell 6 facing the insulating platform 31.

[0067] Specifically, the platform 3, which serves as the place for the battery cell 6, has an insulating surface 31 on the side facing the battery cell 6 to prevent interference.

[0068] In some embodiments, the deflection voltage corresponding to the first laser scanning path is greater than the deflection voltage corresponding to the second laser scanning path.

[0069] Specifically, when laser scanning is performed on the sub-gate electrode 11 in the P region 9, the deflection voltage applied by the power supply device 2 to the battery cell 6 is, for example, 16~22V; when laser scanning is performed on the sub-gate electrode in the N region 10, the deflection voltage applied by the power supply device 2 to the battery cell 6 is, for example, 10~15V.

[0070] In some embodiments, the laser output power corresponding to the first laser scanning path is greater than the laser output power corresponding to the second laser scanning path.

[0071] Specifically, when laser scanning is performed on the sub-gate electrode 11 in region P 9, the laser output power of laser 1 is, for example, 80~100W; when laser scanning is performed on the sub-gate electrode 11 in region N 10, the laser output power of laser 1 is, for example, 40~50W.

[0072] Therefore, by adapting the sub-gate electrode 11 in the P / N region to the target sintering parameters of the two regions, it is beneficial to reduce the contact resistance of the metal electrode in the P / N region, thereby improving the photoelectric conversion efficiency of the TBC cell.

[0073] In some embodiments, the laser emission frequency corresponding to the first laser scanning path is the same as the laser emission frequency corresponding to the second laser scanning path. For example, the laser emission frequency is 50~120kHz.

[0074] This invention also provides a metallization sintering method for battery cells, which is implemented using the metallization sintering system for battery cells described above. Therefore, it has the same or similar beneficial effects, which will not be elaborated here.

[0075] Figure 5 This is a schematic flowchart illustrating a metallization sintering method for a battery cell provided in an embodiment of the present invention. Figure 5 As shown, the metallization sintering method for solar cells includes the following steps:

[0076] S501. Obtain an image of the back side of the solar cell; the back side of the solar cell includes parallel and alternating P-regions and N-regions, each of which has a pre-cured sub-gate electrode.

[0077] Specifically, if Figures 1 to 3 As shown, in this step, the image capturing device 7 is used to acquire the back image of the battery cell 6.

[0078] S502. Determine the first laser scanning path corresponding to the sub-gate electrode in the P region and the second laser scanning path corresponding to the sub-gate electrode in the N region using the back image.

[0079] Specifically, in this step, based on the back image of the battery cell 6 obtained in S501, the location of the sub-gate electrode 111 in the P region and the location of the sub-gate electrode 112 in the N region are determined, thereby obtaining the first laser scanning path corresponding to the sub-gate electrode 11 in the P region and the second laser scanning path corresponding to the sub-gate electrode 11 in the N region.

[0080] S503, Based on laser scanning path control, the laser and power supply equipment perform metallization sintering of the battery cells according to the target sintering parameters.

[0081] The first target sintering parameters corresponding to the first laser scanning path are different from the second target sintering parameters corresponding to the second laser scanning path; the target sintering parameters include the deflection voltage applied to the battery cell by the power supply device and the laser output power emitted by the laser.

[0082] When the P-region sub-gate electrode 111 is metallized and sintered using the LECO process, the first target sintering parameters are used for metallization and sintering of the cell 6; when the N-region sub-gate electrode 112 is metallized and sintered using the LECO process, the second target sintering parameters are used for metallization and sintering of the cell 6. Therefore, corresponding to different fabrication processes and underlying polysilicon thicknesses in the P / N regions, and the different pastes used for printing the metal electrode grid lines, different target sintering parameters can be used for the P / N regions. This allows for free adjustment of the sintering temperature of the two regions, avoiding co-sintering of the P / N regions at the same temperature, and achieving adaptation to the respective sintering temperatures of the P / N regions. This minimizes the contact resistance between the metal electrode and the silicon substrate within the P / N regions.

[0083] In some embodiments, determining the first laser scanning path corresponding to the P-region sub-gate electrode and the second laser scanning path corresponding to the N-region sub-gate electrode using the back image includes:

[0084] Based on the back image, obtain the first drawing pattern corresponding to the region where the sub-gate electrode of the P region is located and the second drawing pattern corresponding to the region where the sub-gate electrode of the N region is located;

[0085] The battery cell area corresponding to the first drawn pattern is used as the first laser scanning path, and the battery cell area corresponding to the second drawn pattern is used as the second laser scanning path.

[0086] Therefore, based on the back image of the solar cell, a first drawing pattern and a second drawing pattern are obtained, thereby determining a first laser scanning path for the first drawing pattern and a second laser scanning path for the second drawing pattern. This allows for adaptation to the sintering temperatures of the P / N regions, minimizing the contact resistance between the metal electrode and the silicon substrate in the P / N region.

[0087] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0088] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the foregoing inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions as those in the present invention.

Claims

1. A metallization sintering system for solar cells, characterized in that, include: Lasers, power supply equipment, imaging equipment, stage and control equipment; The laser, the power supply, and the image capturing device are all communicatively connected to the control device; the stage is used to place the battery cell, and the back of the battery cell includes parallel and alternately arranged P-regions and N-regions, and both the P-regions and the N-regions have pre-cured sub-gate electrodes formed thereon; The image capturing device is used to capture a back image of the battery cell and transmit the back image to the control device; the control device determines the first laser scanning path corresponding to the P-region sub-gate electrode and the second laser scanning path corresponding to the N-region sub-gate electrode based on the back image, and controls the laser and the power supply device to perform metallization sintering of the battery cell according to the target sintering parameters based on the laser scanning paths; The first target sintering parameters corresponding to the first laser scanning path are different from the second target sintering parameters corresponding to the second laser scanning path; the target sintering parameters include the deflection voltage applied by the power supply device to the battery cell and the laser output power of the laser.

2. The metallization sintering system for battery cells according to claim 1, characterized in that, Both the P region and the N region have pre-cured main gate electrodes; the main gate electrode of the P region is intersected with the sub-gate electrode of the P region, and the main gate electrode of the N region is intersected with the sub-gate electrode of the N region. The positive terminal of the power supply device is connected to the N-region main grid electrode, and the negative terminal of the power supply device is connected to the P-region main grid electrode to apply a deflection voltage to the solar cell.

3. The metallization sintering system for battery cells according to claim 2, characterized in that, Also includes: The probe array assembly includes a positive probe array and a negative probe array. The positive terminal of the power supply device is connected to the N-region main gate electrode through the positive probe array, and the negative terminal of the power supply device is connected to the P-region main gate electrode through the negative probe array.

4. The metallization sintering system for battery cells according to claim 3, characterized in that, The back of the battery cell includes a first region, a second region, a third region and a fourth region arranged in sequence, and each region includes P regions and N regions arranged in parallel and alternately. The first region and the second region are electrically connected to the main gate electrodes arranged in the same extending direction, the third region and the fourth region are electrically connected to the main gate electrodes arranged in the same extending direction, and the second region and the third region are electrically disconnected from the main gate electrodes arranged in the same extending direction; the probe array assembly includes a pair; When one probe array assembly is connected to the main gate electrode of the first region and another probe array assembly is connected to the main gate electrode of the fourth region, the laser performs laser scanning on the second region and the third region. One of the probe arrays is connected to the main gate electrode of the second region, and the other probe array is connected to the main gate electrode of the third region. The laser performs laser scanning on the first region and the fourth region.

5. The metallization sintering system for battery cells according to claim 1, characterized in that, The stage includes an insulating platform, and the front of the battery cell faces the insulating platform.

6. The metallization sintering system for battery cells according to claim 1, characterized in that, The deflection voltage corresponding to the first laser scanning path is greater than the deflection voltage corresponding to the second laser scanning path.

7. The metallization sintering system for battery cells according to claim 1, characterized in that, The laser output power corresponding to the first laser scanning path is greater than the laser output power corresponding to the second laser scanning path.

8. The metallization sintering system for battery cells according to claim 1, characterized in that, The laser emission frequency corresponding to the first laser scanning path is the same as the laser emission frequency corresponding to the second laser scanning path.

9. A method for metallizing and sintering a battery cell, characterized in that, It is achieved using the metallization sintering system for the battery cells as described in any one of claims 1-8; The metallization sintering method for the battery cell includes: Obtain a back image of the solar cell; the back of the solar cell includes parallel and alternately arranged P-regions and N-regions, and both the P-regions and the N-regions have pre-cured sub-gate electrodes formed thereon; The first laser scanning path corresponding to the sub-gate electrode in the P region and the second laser scanning path corresponding to the sub-gate electrode in the N region are determined by the back image. Based on the laser scanning path, the laser and the power supply device are controlled to perform metallization sintering of the battery cell according to the target sintering parameters; The first target sintering parameter corresponding to the first laser scanning path is different from the second target sintering parameter corresponding to the second laser scanning path; the target sintering parameter includes the deflection voltage applied by the power supply device to the battery cell and the laser output power emitted by the laser.

10. The metallization sintering method for battery cells according to claim 9, characterized in that, Determining the first laser scanning path corresponding to the P-region sub-gate electrode and the second laser scanning path corresponding to the N-region sub-gate electrode using the back image includes: Based on the back image, a first drawing pattern corresponding to the region where the sub-gate electrode of the P region is located and a second drawing pattern corresponding to the region where the sub-gate electrode of the N region is located are obtained. The battery cell area corresponding to the first drawn pattern is used as the first laser scanning path, and the battery cell area corresponding to the second drawn pattern is used as the second laser scanning path.

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