Method for preventing voltage breakdown phenomenon of laser-assisted sintering

Abstract

The invention relates to a method for preventing a voltage breakdown phenomenon of laser-assisted sintering, and the method is characterized in that a voltage control device is additionally arranged in a reverse voltage unit, the voltage control device can adjust the output voltage in real time according to the parameters of a laser, the operation process can be simplified, and the operation complexity can be reduced; and the accuracy of applying the reverse voltage can be improved. Meanwhile, a voltage stabilizer and a filter are additionally arranged in the backward voltage unit, so that backward voltage applied to the battery piece can be stable, and the voltage breakdown phenomenon caused by backward voltage fluctuation is avoided. Besides, the lightning arrester bypass is arranged in the reverse voltage unit, the reverse voltage main circuit can be short-circuited when the output voltage exceeds the protection voltage of the lightning arrester, the voltage breakdown phenomenon caused by large reverse voltage in the laser-assisted sintering process is avoided, and therefore the quality and performance of the battery piece are guaranteed.

Description

Technical Field

[0001] This disclosure relates to the field of solar cell manufacturing, and more specifically, to a method for preventing voltage breakdown during laser-assisted sintering. Background Technology

[0002] Laser-assisted sintering (LECO), also known as laser-enhanced contact optimization, works by using a high-intensity laser to excite charge carriers in the solar cell while simultaneously applying a reverse voltage to the grid lines. This generates a local current of several amperes, causing sintering of the grid lines and initiating interdiffusion between the metal paste and the cell substrate. This helps reduce the contact resistance between the grid lines and the semiconductor substrate. However, the extremely high energy density of the laser beam during LECO can cause voltage deflection on the solar cell, potentially leading to voltage breakdown. This severely impacts the quality and performance of the solar cell. Therefore, voltage protection technology is crucial in LECO to effectively protect the solar cell from voltage breakdown.

[0003] In existing laser-assisted sintering technologies, voltage control devices are commonly used to prevent voltage breakdown. A voltage control device is a device that automatically limits the voltage; when the voltage exceeds its set threshold, the device automatically activates to limit the voltage within a safe range, thus protecting the solar cells from voltage breakdown. However, the set threshold of the voltage control device needs to be adjusted according to specific operating conditions, which increases operational complexity. Furthermore, voltage control devices can only reduce the risk of voltage breakdown to a certain extent; they cannot completely eliminate the possibility of voltage breakdown. Summary of the Invention

[0004] The purpose of this disclosure is to provide a method for preventing voltage breakdown in laser-assisted sintering, in order to solve the problems of complex operation and inability to completely eliminate voltage breakdown in the prior art.

[0005] To achieve the above objectives, this disclosure provides a method for preventing voltage breakdown in laser-assisted sintering, the method comprising: S1. The solar cells to be sintered are transported to the support platform of the laser sintering device, and the parameters of the laser of the laser sintering device are determined according to the material and size of the solar cells to be sintered. The reverse voltage unit sets its initial output voltage V0 according to the parameters of the laser; The reverse voltage unit includes a voltage control device, a reverse voltage main circuit, and a surge arrester bypass circuit; one end of the surge arrester bypass circuit is connected to the reverse voltage main circuit, and the other end is grounded; the reverse voltage main circuit is equipped with a power supply, electrodes, a voltage regulator, and a filter; the surge arrester bypass circuit is equipped with a surge arrester. The front and back sides of the solar cell to be sintered are respectively brought into contact with the electrodes of the reverse voltage unit; S2. Turn on the power to the laser and the reverse voltage unit, and perform laser sintering. During the laser sintering process, the voltage control device adjusts the real-time output voltage V of the power supply in the reverse voltage unit according to the real-time parameters of the laser. 实时 ; When the real-time output voltage V 实时 When the voltage exceeds the protection voltage of the surge arrester, the surge arrester is bypassed and activated; S3. End the laser sintering process to obtain sintered solar cells.

[0006] Optionally, the surge arrester includes a gapped surge arrester or a gapless metal oxide surge arrester; the rated voltage of the surge arrester is 300V, the maximum continuous operating voltage is 255V, and the maximum discharge current is 60kA.

[0007] Optionally, the protection voltage of the surge arrester is 0~300V.

[0008] Optionally, when the surge arrester is a surge arrester with a gap, an arc extinguishing component is provided at the gap; The arc extinguishing assembly includes a thyristor, a semiconductor device, and a capacitor; the first end of the thyristor is connected to the positive terminal of the gap to be extinguished, and the second end of the thyristor is connected to the negative terminal of the gap to be extinguished through the capacitor; the second end of the thyristor is connected to the control electrode of the first end of the thyristor through the semiconductor device.

[0009] Optionally, the voltage regulator has a voltage regulation accuracy of ±0.5%, a voltage regulation efficiency of over 85%, and an output waveform distortion of less than 3%.

[0010] Optionally, the cutoff frequency of the filter is 50Hz.

[0011] Optionally, the material of the solar cell to be sintered is silicon; the shape of the solar cell is square; the side length of the solar cell is 140~160mm and the thickness is 0.1~0.4mm.

[0012] Optionally, the conditions for the laser sintering process include: laser power of 40~60W, laser scanning speed of 1~10mm / s, and focal length of 10mm.

[0013] Optionally, the output voltage of the power supply in the reverse voltage unit is 0~300V.

[0014] Optionally, the conversion efficiency of the sintered solar cell is 25% to 35%.

[0015] Through the above technical solution, this disclosure adds a voltage control device to the reverse voltage unit. This voltage control device can adjust the output voltage in real time according to the laser parameters, which not only simplifies the operation process and reduces operational complexity, but also improves the accuracy of applying the reverse voltage. Simultaneously, adding a voltage regulator and filter to the reverse voltage unit can stabilize the reverse voltage applied to the solar cell, avoiding voltage breakdown caused by reverse voltage fluctuations. Furthermore, setting a surge arrester bypass in the reverse voltage unit can short-circuit the main reverse voltage circuit when the output voltage exceeds the surge arrester's protection voltage, preventing voltage breakdown caused by large reverse voltages during laser-assisted sintering, thereby ensuring the quality and performance of the solar cell.

[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a reverse voltage unit.

[0018] Figure 2 This is a schematic diagram of an arc-extinguishing component.

[0019] Explanation of reference numerals in the attached figures 1. Laser; 2. Solar cell to be sintered; 3. Electrode; 4. Voltage control device; 5. Voltage regulator; 6. Filter; 7. Surge arrester; A. Arc extinguishing component; Z1. Semiconductor device; TR1. Thyristor; C1. Capacitor. Detailed Implementation

[0020] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0021] This disclosure provides a method for preventing voltage breakdown in laser-assisted sintering, the method comprising: S1. The battery cell 2 to be sintered is transported to the support platform of the laser sintering device, and the parameters of the laser 1 of the laser sintering device are determined according to the material and size of the battery cell to be sintered. The reverse voltage unit sets its initial output voltage V0 according to the parameters of the laser 1. like Figure 1 As shown, the reverse voltage unit includes a voltage control device 4, a reverse voltage main circuit, and a surge arrester bypass circuit; one end of the surge arrester bypass circuit is connected to the reverse voltage main circuit, and the other end is grounded; the reverse voltage main circuit is provided with a power supply, an electrode 3, a voltage regulator 5, and a filter 6; the surge arrester bypass circuit is provided with a surge arrester 7; The front and back sides of the battery cell 2 to be sintered are respectively brought into contact with the electrodes 3 of the reverse voltage unit; S2. Turn on the power to the laser 1 and the reverse voltage unit, and perform laser sintering. During the laser sintering process, the voltage control device 4 adjusts the real-time output voltage V of the power supply in the reverse voltage unit according to the real-time parameters of the laser 1. 实时 ; When the real-time output voltage V 实时 When the voltage exceeds the protection voltage of the surge arrester 7, the surge arrester bypass is activated; S3. End the laser sintering process to obtain sintered solar cells.

[0022] Through the above technical solution, this disclosure adds a voltage control device 4 to the reverse voltage unit. This voltage control device 4 can adjust the output voltage in real time according to the parameters of the laser 1, which not only simplifies the operation process and reduces operational complexity, but also improves the accuracy of applying the reverse voltage. Simultaneously, adding a voltage regulator 5 and a filter 6 to the reverse voltage unit can stabilize the reverse voltage applied to the solar cell, avoiding voltage breakdown caused by reverse voltage fluctuations. Furthermore, setting a surge arrester bypass in the reverse voltage unit can short-circuit the main reverse voltage circuit when the output voltage exceeds the protection voltage of the surge arrester 7, avoiding voltage breakdown caused by large reverse voltages during laser-assisted sintering, thereby ensuring the quality and performance of the solar cell.

[0023] In one embodiment, the laser 1 used in this disclosure is a conventional choice in the art, and this application does not make any special requirements. For example, the laser 1 is a laser from DIL Company.

[0024] In one embodiment, the laser 1 outputs a laser with a wavelength of 690nm and a maximum output power of 1000W.

[0025] In one embodiment, the material of the solar cell used in this disclosure is silicon, that is, the solar cell is a silicon wafer.

[0026] In a preferred embodiment, the silicon wafer is a monocrystalline silicon wafer for solar cells.

[0027] In one embodiment, the shape of the battery cell used in this disclosure can be circular or square.

[0028] In a preferred embodiment, the battery cell is square in shape, with a side length of 140~160mm and a thickness of 0.1~0.4mm.

[0029] In a further preferred embodiment, the battery cell has a side length of 150 mm and a thickness of 0.2 mm.

[0030] In one embodiment, step S1 further includes turning on the voltage control device 4, making the voltage control device 4 receive the setting parameters of the laser 1, and determining the initial output voltage V0 of the reverse voltage unit based on these parameters.

[0031] In one embodiment, the output voltage V0 is 10~250V.

[0032] In one embodiment, step S2 further includes operating at the initial output voltage V0 when the power supply in the reverse voltage unit is turned on.

[0033] In one embodiment, the voltage control device 4 is electrically connected to the laser 1 and the power supply, and is used to adjust the real-time output voltage of the power supply according to the real-time parameters of the laser 1.

[0034] In one embodiment, step S2 further includes, during the laser sintering process, the voltage control device 4 adjusts the real-time output voltage V of the reverse voltage unit according to the real-time parameters of the laser 1. 实时 .

[0035] In one embodiment, the voltage control device 4 described in this disclosure is an E70.C3K piezoelectric controller.

[0036] In one embodiment, the voltage regulator 5 described in this disclosure is a linear voltage regulator; the voltage regulation accuracy of the voltage regulator 5 is ±0.5%, the voltage regulation efficiency is above 85%, and the output waveform distortion is below 3%.

[0037] In one embodiment, the filter 6 described in this disclosure is a low-pass filter; the cutoff frequency of the filter 6 is 50Hz.

[0038] In one embodiment, the parameters of the surge arrester 7 disclosed herein include: a rated voltage of 300V, a maximum continuous operating voltage of 255V, and a maximum discharge current of 60kA.

[0039] In one embodiment, the protection voltage of the surge arrester 7 is 0~300V.

[0040] In a preferred embodiment, the protection voltage of the surge arrester 7 is 10~250V.

[0041] In one embodiment, the surge arrester 7 described in this disclosure includes a gapped surge arrester or a gapless metal oxide surge arrester. In this embodiment, when the surge arrester 7 is a gapped surge arrester, the current enters the surge arrester 7 through the surge arrester bypass. Due to the gap in the surge arrester 7, a voltage difference is generated at the gap. When the voltage difference is large enough, an electric arc is generated between the gaps, causing the surge arrester 7 to conduct. When the surge arrester 7 is a gapless metal oxide surge arrester, during normal use, the surge arrester 7 acts as a resistor with a very high resistance, and almost no current flows through it. When the voltage is large enough, the surge arrester 7 conducts. After the surge arrester 7 conducts, it conducts all the current to the ground. At this time, the battery cells are short-circuited, and no reverse voltage is injected.

[0042] In one embodiment, when the surge arrester 7 is a gapped surge arrester, an electric arc will be generated when the surge arrester 7 is conducting, which may have a negative impact on the quality and performance of the solar cells and other components. To avoid the negative impact caused by the electric arc, an arc-extinguishing component A can be installed at the gap of the surge arrester 7.

[0043] like Figure 2 As shown, the arc extinguishing component A includes a thyristor TR1, a semiconductor device Z1, and a capacitor C1; the first end of the thyristor TR1 is connected to the positive terminal of the gap to be extinguished, and the second end of the thyristor TR1 is connected to the negative terminal of the gap to be extinguished through the capacitor C1; the second end of the thyristor TR1 is connected to the control terminal of the first end of the thyristor TR1 through the semiconductor device Z1.

[0044] In a preferred embodiment, the surge arrester 7 is a gapless metal oxide surge arrester. In this embodiment, when the surge arrester 7 is a gapless metal oxide surge arrester, almost no arc is generated during conduction; therefore, there is no need to install the arc extinguishing assembly A.

[0045] In a further preferred embodiment, the gapless metal oxide surge arrester 7 is a zinc oxide surge arrester.

[0046] In one embodiment, the conditions for the laser sintering process include: a laser power of 40-60W, a laser scanning speed of 1-10mm / s, and a focal length of 10mm.

[0047] In one embodiment, the output voltage of the power supply in the reverse voltage unit is 0~300V, preferably 10~220V.

[0048] In one embodiment, the conversion efficiency of the sintered solar cell is 25% to 35%.

[0049] In one embodiment, a method for preventing voltage breakdown in laser-assisted sintering includes: S1. The solar cell 2 to be sintered is transported to the support platform of the laser sintering device. The parameters of the laser 1 of the laser sintering device are determined according to the material and size of the solar cell to be sintered. The parameters of the laser 1 include: laser power of 40~60W, laser scanning speed of 1~10mm / s, and focal length of 10mm. The reverse voltage unit is set to an initial output voltage V0 according to the parameters of the laser 1; the initial output voltage V0 is 0~300V; The front and back sides of the battery cell 2 to be sintered are respectively brought into contact with the electrodes 3 of the reverse voltage unit; S2. Turn on laser 1 and the reverse voltage unit to perform laser sintering; During the laser sintering process, the voltage control device 4 adjusts the real-time output voltage V of the reverse voltage unit according to the real-time parameters of the laser 1. 实时 ; When the real-time output voltage V of the reverse voltage unit 实时 When the voltage exceeds the protection voltage of surge arrester 7, the surge arrester bypass is activated; S3. End the sintering process to obtain sintered battery cells.

[0050] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0051] Example 1 Reverse voltage unit such as Figure 1 As shown, the voltage regulator 5 in this unit has a voltage regulation accuracy of ±0.5%, a voltage regulation efficiency of over 85%, and an output waveform distortion of less than 3%; the cutoff frequency of the filter 6 is 50Hz; the surge arrester 7 is a zinc oxide surge arrester with a rated voltage of 300V, a maximum continuous operating voltage of 255V, a maximum discharge current of 60kA, and a protection voltage of 250V. Methods to prevent voltage breakdown in laser-assisted sintering include: S1. A square silicon wafer with a side length of 150mm and a thickness of 0.2mm is transported to the support platform of the laser sintering device. The parameters of the laser 1 of the laser sintering device are determined according to the silicon wafer. The parameters of the laser 1 include: laser power of 50W, laser scanning speed of 10mm / s, and focal length of 10mm. The reverse voltage unit is set to an initial output voltage V0 according to the parameters of the laser 1; the initial output voltage V0 is 220V. The front and back sides of the battery cell 2 to be sintered are respectively brought into contact with the electrodes 3 of the reverse voltage unit; S2. Turn on laser 1 and reverse voltage unit to perform laser sintering; During the laser sintering process, the voltage control device 4 adjusts the real-time output voltage V of the reverse voltage unit according to the real-time parameters of the laser 1. 实时 ; When the real-time output voltage V of the reverse voltage unit 实时 When the voltage is greater than 250V, the surge arrester bypass is activated; S3. End the sintering process to obtain sintered battery cells.

[0052] By employing the method disclosed herein, the reverse voltage unit, under the action of the voltage control device 4, voltage regulator 5, filter 6, and surge arrester 7, can, on the one hand, simplify the operation process and reduce operational complexity while improving the accuracy of applying reverse voltage; on the other hand, it can stabilize the reverse voltage applied to the solar cell, avoiding voltage breakdown caused by reverse voltage fluctuations; furthermore, it can short-circuit the main reverse voltage circuit when the output voltage exceeds the protection voltage of the surge arrester 7, avoiding voltage breakdown caused by large reverse voltage during laser-assisted sintering, thereby ensuring the quality and performance of the solar cell.

[0053] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0054] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0055] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for preventing voltage breakdown in laser-assisted sintering, characterized in that, The method includes: S1. The solar cells to be sintered are transported to the support platform of the laser sintering device, and the parameters of the laser of the laser sintering device are determined according to the material and size of the solar cells to be sintered. The reverse voltage unit sets its initial output voltage V0 according to the power parameters of the laser; The reverse voltage unit includes a voltage control device, a reverse voltage main circuit, and a surge arrester bypass circuit; one end of the surge arrester bypass circuit is connected to the reverse voltage main circuit, and the other end is grounded; the reverse voltage main circuit is equipped with a power supply, electrodes, a voltage regulator, and a filter; the surge arrester bypass circuit is equipped with a surge arrester. The front and back sides of the solar cell to be sintered are respectively brought into contact with the electrodes of the reverse voltage unit; S2. Turn on the power to the laser and the reverse voltage unit, and perform laser sintering. During the laser sintering process, the voltage control device adjusts the real-time output voltage V of the power supply in the reverse voltage unit according to the real-time parameters of the laser. 实时 ; When the real-time output voltage V 实时 When the voltage exceeds the protection voltage of the surge arrester, the surge arrester is bypassed and activated; S3. End the laser sintering process to obtain sintered solar cells.

2. The method according to claim 1, characterized in that, The surge arrester includes a gapped surge arrester or a gapless metal oxide surge arrester; The surge arrester has a rated voltage of 300V, a maximum continuous operating voltage of 255V, and a maximum discharge current of 60kA.

3. The method according to claim 2, characterized in that, The protection voltage of the surge arrester is 0~300V.

4. The method according to claim 2, characterized in that, When the surge arrester is a surge arrester with a gap, an arc extinguishing component is provided at the gap; The arc extinguishing assembly includes a thyristor, a semiconductor device, and a capacitor; The first end of the thyristor is connected to the positive terminal of the gap to be extinguished by arc suppression, and the second end of the thyristor is connected to the negative terminal of the gap to be extinguished by arc suppression through the capacitor; the second end of the thyristor is connected to the control electrode of the first end of the thyristor through the semiconductor device.

5. The method according to claim 1, characterized in that, The voltage regulator has a voltage regulation accuracy of ±0.5%, a voltage regulation efficiency of over 85%, and an output waveform distortion of less than 3%.

6. The method according to claim 1, characterized in that, The cutoff frequency of the filter is 50Hz.

7. The method according to claim 3, characterized in that, The solar cell to be sintered is made of silicon; the solar cell is square in shape; the side length of the solar cell is 140~160mm and the thickness is 0.1~0.4mm.

8. The method according to claim 7, characterized in that, The conditions for the laser sintering process include: laser power of 40~60W, laser scanning speed of 1~10mm / s, and focal length of 10mm.

9. The method according to claim 1, characterized in that, The output voltage of the power supply in the reverse voltage unit is 0~300V.

10. The method according to claim 1, characterized in that, The conversion efficiency of the sintered solar cell is 25%~35%.

Images