A thin-film solar cell etching light transmittance dynamic control system and method

Abstract

The application discloses a thin-film solar cell etching light transmittance dynamic control system and method, and solves the technical problems of unstable etching line spacing and excessive light transmittance deviation caused by speed fluctuation of a moving platform in dynamic processing. The system comprises a moving platform module, a galvanometer scanning module and a light transmittance control unit. A speed sensor collects the actual speed of the platform in real time, a PID adjusting unit calculates a center spacing correction amount according to a target light transmittance preset value and the actual speed, and a laser frequency adjusting module synchronously adjusts the emission frequency according to the formula f=v / d, so as to ensure that the etching line spacing dynamically adapts to the speed change. The light transmittance deviation is stably controlled to be less than or equal to 3%, the problem of unstable light transmittance caused by speed fluctuation is solved, the processing efficiency is improved by more than 40%, the yield reaches 99.5%, and the system is suitable for etching of thin-film batteries such as cadmium telluride and perovskite.

Description

TECHNICAL FIELD

[0001] The present application relates to a thin-film solar cell etching light transmittance dynamic control system and method, and belongs to the technical field of thin-film solar cell manufacturing. BACKGROUND

[0002] The existing thin-film solar cell laser etching processing technology has the technical problem of poor stability of the light transmittance of the thin-film solar cell. In the laser etching process of the thin-film solar cell, the control of the speed of the moving platform is relatively rough, for example, 200 mm per second. The line width and line bundle interval of the laser etching line are in the order of tens of micrometers. The normal fluctuation of the speed of the moving platform will have a great impact on the traditional fixed etching line spacing processing method, thereby causing the actual light transmittance to deviate from the target light transmittance beyond the acceptable range, and affecting the balance between the visual permeability and the photoelectric conversion efficiency of the thin-film solar cell in the scenarios of building curtain walls and light-transmitting roofs.

[0003] Therefore, the existing technology has defects and needs to be further improved and perfected. SUMMARY

[0004] In view of the above-mentioned deficiencies of the prior art, the purpose of the present application is to provide a thin-film solar cell etching light transmittance dynamic control system and method, especially a system for realizing stable control of light transmittance by adjusting the etching line spacing in a dynamic continuous processing mode.

[0005] According to the embodiment of the present application, the first scheme is provided: a thin-film solar cell etching light transmittance dynamic control system, comprising:

[0006] A moving platform module, which carries a thin-film solar cell substrate and continuously moves in a preset direction at a preset speed;

[0007] A galvanometer scanning module, which emits a laser beam to the surface of the thin-film solar cell substrate and forms an etching line in the continuous movement of the thin-film solar cell substrate;

[0008] A light transmittance control unit, comprising a speed sensor and a PID adjustment unit, the speed sensor collects the actual speed of the moving platform module in real time, and the PID adjustment unit adjusts the center distance of adjacent etching lines of the galvanometer scanning module in real time according to the target light transmittance preset value and the actual speed to maintain the target light transmittance deviation within the light transmittance deviation threshold.

[0009] Further, the preset speed of the moving platform module is 200-800 mm / s, and the preset direction is the Y-axis direction, wherein the overall feeding direction of the moving platform module is defined as the Y-axis direction, and the vertical direction of the overall feeding direction of the moving platform module on the horizontal plane is the X-axis direction.

[0010] Further, the laser beam emitted by the galvanometer scanning module has the following parameters: wavelength of 1064 nm, pulse width of picosecond to nanosecond, and line width of 10-50 μm; the laser beam penetrates the back electrode layer and the absorption layer of the thin-film solar cell substrate without damaging the transparent conductive oxide layer.

[0011] Further, the PID adjusting unit comprises:

[0012] a deviation calculating module configured to receive a target light transmittance preset value and an actual light transmittance measured value, and calculate an actual light transmittance deviation;

[0013] a proportional-integral-derivative adjusting module configured to output a center distance correction value according to the actual light transmittance deviation;

[0014] an output limiting module configured to limit the center distance correction value within a center distance correction value limiting range, so as to avoid the etching line from being broken due to sudden change of the center distance;

[0015] a frequency control module configured to calculate a corrected center distance according to the initial center distance and the limited center distance correction value, and adjust the laser emission frequency of the galvanometer scanning module according to the corrected center distance and the actual speed.

[0016] Further, the center distance correction value limiting range is ±20 μm.

[0017] Further, the light transmittance deviation threshold value is 2%-4%, and preferably 3%.

[0018] Further, the system further comprises a motion synchronization control module, which comprises a platform encoder, a path planning unit, and a PLC controller; the platform encoder collects displacement data of the motion platform module in real time and feeds back to the PLC controller, the displacement data comprising the actual speed and actual position of the thin-film solar cell; the path planning unit generates an array pattern of the etching line, and divides the thin-film solar cell substrate into a plurality of rectangular field units, and simultaneously generates a continuous serpentine path of the galvanometer scanning for each rectangular field unit; the PLC controller triggers the galvanometer scanning module to control the laser beam to generate the etching line with linear energy gradient on both sides of the splicing boundary of adjacent rectangular field units.

[0019] According to the embodiments of the present application, the first scheme provided by the thin-film solar cell etching light transmittance dynamic control system is used to provide a second scheme.

[0020] A thin-film solar cell etching light transmittance dynamic control method comprises the following steps:

[0021] S1: fixing the thin-film solar cell substrate on the motion platform module;

[0022] S2: continuously moving the thin-film solar cell substrate along the Y-axis direction at a constant speed within a preset speed range by the motion platform module;

[0023] S3: starting the galvanometer scanning module, which emits a laser beam to the surface of the thin-film solar cell substrate to form parallelly arranged etching lines;

[0024] S4: real-time acquisition of the actual speed of the motion platform module by the speed sensor in the light transmittance control unit;

[0025] S5: real-time adjustment of the center-to-center distance of adjacent etching lines of the galvanometer scanning module by the PID adjustment unit in the light transmittance control unit according to the target light transmittance preset value and the actual speed to maintain the target light transmittance deviation within the light transmittance deviation threshold.

[0026] Further, the step of real-time adjustment of the center-to-center distance of adjacent etching lines of the galvanometer scanning module by the PID adjustment unit in the light transmittance control unit according to the target light transmittance preset value and the actual speed to maintain the target light transmittance deviation within the light transmittance deviation threshold comprises:

[0027] S50: calculation of the initial center-to-center distance by the path planning unit according to the target light transmittance preset value and the laser beam line width;

[0028] S51: real-time calculation of the center-to-center distance correction of adjacent etching lines by the PID adjustment unit according to the target light transmittance preset value and the actual speed;

[0029] Calculation of the corrected center-to-center distance according to the center-to-center distance and the center-to-center distance correction, adjustment of the laser emission frequency of the galvanometer scanning module according to the corrected center-to-center distance and the actual speed, and etching of the next etching line by the laser beam according to the corrected center-to-center distance and the adjusted laser emission frequency to maintain the deviation of the actual light transmittance from the target light transmittance within the light transmittance deviation threshold.

[0030] Further, the step of adjusting the laser emission frequency of the galvanometer scanning module according to the corrected center-to-center distance and the actual speed comprises:

[0031] Real-time adjustment of the laser emission frequency of the galvanometer scanning module by the laser frequency adjustment module according to the corrected center-to-center distance d and the actual speed v through the formula f=v / d, wherein the value range of the corrected center-to-center distance d is 50-200 μm, the value range of the actual speed v is 200-800 mm / s, the adjustment range of the laser emission frequency f is 1-4 kHz, and the adjustment response delay is ≤10 μs, to maintain the target light transmittance deviation ≤3%.

[0032] Compared with the prior art, the technical scheme provided by the application has the beneficial effects of:

[0033] The speed sensor in the light transmittance control unit collects the actual speed of the motion platform in real time, and the PID adjusting unit adjusts the center line spacing of adjacent etching lines in real time according to the target light transmittance preset value and the actual speed, effectively offsets the influence of speed fluctuation on the spacing, and thereby stably maintains the deviation of the actual light transmittance from the target light transmittance within the light transmittance deviation threshold, thereby solving the technical problem of unstable light transmittance in dynamic processing. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0035] Among them:

[0036] Figure 1 It is a structural block diagram of a thin-film solar cell etching light transmittance dynamic control system in an embodiment;

[0037] Figure 2 It is a flowchart of a thin-film solar cell etching light transmittance dynamic control method in an embodiment. DETAILED DESCRIPTION

[0038] In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0039] Embodiment one

[0040] The present embodiment aims at the technical problem of poor light transmittance stability in the existing thin-film solar cell laser etching processing: during dynamic processing, the speed fluctuation of the motion platform, for example, the change in the range of 200-800mm / s, will cause the traditional fixed etching line spacing processing method to be unable to adapt to the speed change, the actual light transmittance deviates from the target light transmittance by more than 5%, and cannot meet the demand of uniform light transmittance in the building curtain wall scene;

[0041] Meanwhile, laser etching is focused on the material surface by a high-energy laser beam (such as 1064 nm wavelength, picosecond / nanosecond pulse width), so that the local area absorbs energy and rapidly heats up to the melting or gasification temperature to form etching lines. When the etching line spacing is suddenly reduced from 200 μm to 50 μm, the number of etching lines per unit area increases by 4 times, resulting in an increase in the total energy absorbed per unit area. The absorption layer (such as CIGS, perovskite) of the thin-film solar cell is a brittle material with low thermal conductivity. The sudden increase in energy can cause the local temperature to exceed the melting point of the material, forming over-etched pits. The material at the edge of the pit breaks due to thermal stress, forming a broken line. When the spacing is suddenly increased from 50 μm to 200 μm, the energy density per unit area decreases by 75%, and the laser cannot completely penetrate the target layer. The remaining material forms a bridge, which breaks due to mechanical stress during subsequent processing, appearing as a broken line. Therefore, the sudden change in etching line spacing can easily cause a broken line, affecting the series resistance of the cell.

[0042] To solve the above technical problems, the embodiment provides a thin-film solar cell etching light transmittance dynamic control system, as shown in Figure 1 The system comprises:

[0043] (1) a motion platform module 100, which carries a thin-film solar cell substrate and continuously moves in a preset direction at a preset speed;

[0044] The motion platform module comprises a vacuum adsorption table, for example, a size of 1.2 m x 2.2 m, a Y-axis linear motor with a maximum speed of 1000 mm / s, and a mechanical limiting mechanism.

[0045] The motion platform module carries a 1 m x 2 m perovskite thin-film substrate through a vacuum adsorption platform. Specifically, the perovskite thin-film substrate can be a flexible substrate, which is fixed by vacuum adsorption and continuously moves at a constant speed of 400 mm / s along the Y-axis direction, with a speed fluctuation of ≤±2%.

[0046] (2) a galvanometer scanning module 200, which emits a laser beam to the surface of the thin-film solar cell substrate and forms etching lines during the continuous movement of the thin-film solar cell substrate;

[0047] The laser wavelength is 1064 nm, the pulse width is 20 ns (nanosecond level), the line width is 30 μm, and the power is 30 W. The laser beam penetrates the back electrode layer (Mo, thickness 500 nm) and the absorption layer (perovskite, thickness 400 nm) without damaging the TCO layer (ITO, thickness 800 nm).

[0048] (Three) light transmittance control unit 400, including speed sensor and PID adjusting unit, the speed sensor real-time acquisition of the actual speed of the motion platform module, the PID adjusting unit adjusts the center distance of adjacent etching lines of the galvanometer scanning module according to the target light transmittance preset value and the actual speed to maintain the target light transmittance deviation within the light transmittance deviation threshold.

[0049] The light transmittance control unit is the core module. Specifically, the high-precision laser Doppler speed sensor is selected as the speed sensor, the sampling frequency is 1 kHz, the measurement range is 0-1000 mm / s, and the accuracy is ±0.1 mm / s. The actual speed of the motion platform is collected in real time by the high-precision laser Doppler speed sensor, and the data is transmitted to the PID adjusting unit.

[0050] The PID adjusting unit (proportion-integral-derivative) includes:

[0051] The deviation calculation module receives the target light transmittance preset value (40%) and the actual light transmittance measurement value (detected online by the CCD), and calculates the deviation ( of the actual light transmittance).

[0052] The proportion-integral-derivative adjusting module outputs the center distance correction amount Δd according to the deviation e, the proportion coefficient Kp=1.0, the integral time Ti=0.2s, and the differential time Td=0.05s; for example, when e=+2% (actual light transmittance 38%), output Δd=-10μm to reduce the distance to increase the light transmittance.

[0053] The output limiting module limits Δd to ±20μm to avoid the fracture of the etching line caused by the sudden change of the distance.

[0054] The frequency control module calculates the initial center distance , from the path planning unit ;

[0055] The limited Δd calculates the corrected center distance (such as 75μm-10μm=65μm); the laser emission frequency is adjusted by the formula f=v / d.

[0056] When v=400mm / s, f=400×10³μm / s ÷65μm≈6.15kHz.

[0057] (Four) motion synchronization control module, including platform encoder: 24-bit absolute value encoder, real-time acquisition of displacement data, feedback to PLC controller.

[0058] Path planning unit: generate an array pattern, which is a parallel etching line with an initial pitch of 75 pm, divide the thin-film solar cell substrate into 50x50 mm2 rectangular field units, and generate a serpentine path for each unit to achieve high-frequency reciprocating scanning of the laser beam in the X-axis and continuous movement in the Y-axis.

[0059] PLC controller: control the linear gradient adjustment of laser energy (100%→95%) in the transition zone of ±50 pm at the splicing boundary to ensure that the splicing error of adjacent units is ≤±3 pm and avoid local transmittance fluctuations.

[0060] Technical effects of the embodiment:

[0061] Significant improvement in transmittance stability: real-time correction of the center pitch by the PID adjustment unit, combined with dynamic adjustment of the laser emission frequency, controls the deviation of the actual transmittance from the target value to within 3%, solving the problem of unstable transmittance caused by speed fluctuations.

[0062] Optimization of etching line quality: the output limiting module avoids pitch mutations, and the etching line breakage rate is reduced from the traditional 5% to 0.3%, with a series resistance stability of ≤0.5 Ω·cm².

[0063] Processing precision and efficiency synergy: the motion synchronization control module divides the rectangular field units and scans the serpentine path, with a processing efficiency of 200 seconds / m², a splicing error of ≤±3 pm, and a double demand for visual permeability and power generation efficiency in the building photovoltaic integration scenario.

[0064] The embodiment realizes dynamic and stable control of the etching transmittance of thin-film solar cells through the coordinated work of the motion platform, galvanometer scanning, transmittance control, and motion synchronization control module, effectively solves the problems of large transmittance deviation and poor etching line quality in traditional processing, and the technical progress is significant.

[0065] Embodiment two

[0066] Based on the scheme of embodiment one, the existing system only controls the splicing error by linear gradient adjustment of laser energy (100%→95%) in the transition zone of ±50 pm at the splicing boundary, but the test shows that the center pitch fluctuation also affects the transmittance. If this influence is not considered in the calculation, the following problems will occur: transition zone transmittance fluctuation: when the motion platform speed fluctuates, the PID adjustment unit will increase the center pitch, while the energy in the transition zone has been reduced to 95%, and the double factors superimposed cause the local transmittance deviation to exceed the threshold instantaneously; Energy and pitch adjustment are not synchronized: energy gradient adjustment and center pitch correction are independently executed by the PLC controller and the PID adjustment unit, respectively, with a time difference >10 ms, resulting in a transient window of energy and pitch mismatch in the transition zone.

[0067] In order to solve the technical problems, the thin film solar cell etching light transmittance dynamic control system of the embodiment, the motion synchronous control module and the light transmittance control unit further comprise transition zone cooperative adjustment logic; when the PLC controller detects that the laser etching point enters the transition zone of ±50μm of the splicing boundary of the adjacent rectangular field unit, a transition zone trigger signal is synchronously sent to the PID adjustment unit, the amplitude limiting range of the center distance correction amount is temporarily reduced from ±20μm to ±5μm, and the center distance is dynamically corrected according to the linear gradient adjustment proportion (100%→95%) of the laser energy, so that the actual light transmittance deviation in the transition zone is maintained at ≤2%.

[0068] Specifically, 1. The PLC controller monitors the position of the laser etching point in real time through the encoder, and sends a 2-byte transition zone trigger signal to the PID adjustment unit when the etching point is 50μm away from the splicing boundary, which contains the boundary position and energy gradient instruction, and the signal transmission delay is ≤5μs, which is realized through the EtherCAT bus.

[0069] 2. After the PID adjustment unit receives the trigger signal, the amplitude limiting range of the center distance correction amount Δd is temporarily reduced from the regular ±20μm to ±5μm, so as to avoid the sudden change of the distance; when the etching point leaves the transition zone, the amplitude limiting range is automatically restored to ±20μm, and the restoration delay is ≤1ms.

[0070] 3. According to the laser energy gradient adjustment proportion (E, 100%→95%), the center distance compensation value Δd_compensation is dynamically calculated:

[0071]

[0072] (wherein is the initial center distance outside the transition zone, such as 60μm; when E=95%, Δd_compensation=60μm×5%=3μm);

[0073] The execution logic is that the PID adjustment unit adds Δd_compensation to the regular correction amount Δd, so that the actual center distance in the transition zone ensures that the energy is reduced while the distance is correspondingly reduced, and the light transmittance is maintained stable.

[0074] Taking a 1m×2m cadmium telluride thin film substrate as an example (target light transmittance 40%, initial center distance =75μm):

[0075] Transition zone entry stage:

[0076] When the etching point reaches the splicing boundary-50μm, the PLC sends a trigger signal, and the energy starts to linearly decay from 100%;

[0077] PID regulating unit limits Δd from ±20μm→±5μm, while calculating Δd_compensation=75μm×(1-95%)=3.75μm≈4μm;

[0078] If the conventional Δd=+5μm (due to speed reduction, the spacing needs to be increased), then the actual Δd=+5μm+4μm=+9μm, d_transition=75μm+5μm=80μm.

[0079] Transition zone exit phase:

[0080] When the etching point reaches the splicing boundary +50μm, the energy is restored to 100%, Δd_compensation=0, the limit is restored to ±20μm, d_transition=75μm+conventional Δd.

[0081] Through the above-mentioned embodiment scheme, the transition zone light transmittance deviation is reduced from the conventional 3% to 1.8%, the threshold value of the first embodiment; the local Mura defect contrast is reduced from 5% to <2%, which is invisible to the human eye. The synchronization error of energy and spacing adjustment is ≤3μs, and the transition zone processing time is completed within 0.1ms for double adjustment; the splicing error is maintained at ±2.5μm, and the TCO layer damage rate is 0.3%. Without adding new hardware, it is realized through software logic optimization, suitable for full speed range of 200-800mm / s, and verified effective in perovskite, copper indium gallium selenide and other materials.

[0082] Example Three

[0083] In view of the technical problems of existing thin-film solar cell etching light transmittance dynamic control method, such as center spacing correction lag, laser frequency adjustment not timely and poor light transmittance stability, which is specifically manifested as: the traditional PID regulating unit parameters, such as proportional coefficient, integral time, etc. are fixed, when the motion platform speed fluctuates in a large range of 200-800mm / s, the center spacing correction amount calculation lags >15ms, resulting in actual light transmittance deviation instantaneously exceeding 3%; the laser frequency adjustment module does not associate the corrected center spacing in real time, and still calculates the frequency according to the initial spacing, resulting in actual spacing deviation of etching line ±5μm and light transmittance fluctuation >4%; the path planning unit does not consider the actual processing deviation of laser line width, resulting in initial center spacing calculation error, and superimposed light transmittance deviation after speed fluctuation exceeds the threshold value.

[0084] The embodiment realizes light transmittance dynamic control through the following specific process, as shown in Figure 2

[0085] S1: Fix the thin-film solar cell substrate on the motion platform module;

[0086] ​A 1m x 2m cadmium telluride thin film substrate was fixed on a motion platform module by vacuum adsorption, the substrate thickness was 0.5mm, the back electrode layer (Mo) thickness was 500nm, the absorption layer (CdTe) thickness was 3μm, and the transparent conductive oxide layer (TCO) thickness was 800nm.

[0087] S2: The motion platform module continuously moved the thin film solar cell substrate along the Y-axis direction at a constant speed within the preset speed range.

[0088] The motion platform module continuously moved the substrate along the Y-axis direction at a constant speed of 500mm / s, and the speed fluctuation was maintained within ±0.5% through closed-loop control.

[0089] S3: The galvanometer scanning module was started, which emitted a laser beam to the surface of the thin film solar cell substrate to form parallel etching lines.

[0090] The galvanometer scanning module emitted a laser beam with a wavelength of 1064nm, a pulse width of 20ns, and a line width of 30μm, forming parallel etching lines on the substrate surface, and the initial laser emission frequency was set to 6.7kHz.

[0091] S4: The actual speed of the motion platform module was collected in real time by the speed sensor in the light transmittance control unit.

[0092] The speed sensor (sampling frequency 1kHz, accuracy ±0.1mm / s) collected the actual speed of the platform in real time, and when the speed fluctuated from 500mm / s to 550mm / s, the data was transmitted in real time to the PID adjustment unit.

[0093] S5: The PID adjustment unit in the light transmittance control unit adjusted the center-to-center distance of adjacent etching lines of the galvanometer scanning module in real time according to the target light transmittance preset value and the actual speed to maintain the deviation of the target light transmittance within the light transmittance deviation threshold.

[0094] PID adjustment and laser frequency adjustment:

[0095] S50: The path planning unit calculated the initial center-to-center distance according to the target light transmittance preset value and the laser beam line width.

[0096] S51: The PID adjustment unit calculated the center-to-center distance correction of adjacent etching lines in real time according to the target light transmittance preset value and the actual speed.

[0097] The corrected center-to-center distance was calculated according to the center-to-center distance and the center-to-center distance correction, and the laser emission frequency of the galvanometer scanning module was adjusted according to the corrected center-to-center distance and the actual speed, and the laser beam etched the next etching line according to the corrected center-to-center distance and the adjusted laser emission frequency to maintain the deviation of the actual light transmittance and the target light transmittance within the light transmittance deviation threshold.

[0098] The laser frequency adjustment module adjusts the laser emission frequency of the galvanometer scanning module in real time according to the corrected center distance d and the actual speed v through the formula f=v / d, wherein the value range of the corrected center distance d is 50-200μm, the value range of the actual speed v is 200-800mm / s, the adjustment range of the laser emission frequency f is 1-4kHz, and the adjustment response delay is ≤10μs, so as to maintain the target transmittance deviation ≤3%.

[0099] The technical advantages of the thin-film solar cell etching transmittance dynamic control method of the embodiment are as follows:

[0100] Transmittance stability is improved: the PID adjustment unit is used to correct the center distance and dynamically match the laser frequency in real time, the actual transmittance deviation from the target value (40%) is controlled within 2.5%, and the transmittance deviation caused by speed fluctuation is solved.

[0101] Etching line uniformity is optimized: the corrected center distance deviation is ≤±1μm, the laser frequency and speed matching accuracy is ±0.1kHz, the etching line width uniformity, and the series resistance is stabilized at 0.4Ω·cm².

[0102] Processing efficiency is guaranteed: the processing time of a single square meter of substrate is shortened from 380 seconds to 205 seconds, the efficiency is improved by more than 40%, the yield is improved synchronously, and the requirements of mass production rhythm are met.

[0103] The whole process method of initial distance calculation, PID dynamic correction, and frequency real-time matching is used in the embodiment, which effectively solves the problems of response lag and matching error in traditional control, and realizes high-precision dynamic control of thin-film solar cell etching transmittance.

[0104] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer readable storage medium, and when the program is executed, the processes of the above-mentioned embodiment methods can be included. Any reference to memory, storage, databases, or other media in the embodiments provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct Rambus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0105] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0106] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A thin-film solar cell etching light transmittance dynamic control system, characterized in that, The method comprises the following steps: A motion platform module carries a thin-film solar cell substrate and continuously moves at a preset speed in a preset direction; A galvanometer scanning module emits a laser beam to the surface of the thin-film solar cell substrate and forms an etching line during the continuous movement of the thin-film solar cell substrate; A light transmittance control unit comprises a speed sensor and a PID adjustment unit, the speed sensor collects the actual speed of the motion platform module in real time, and the PID adjustment unit adjusts the center distance of adjacent etching lines of the galvanometer scanning module in real time according to the target light transmittance preset value and the actual speed to maintain the target light transmittance deviation within the light transmittance deviation threshold; The PID adjustment unit comprises: A deviation calculation module receives the target light transmittance preset value and the actual light transmittance measurement value, and calculates the actual light transmittance deviation; A proportional-integral-derivative adjustment module outputs a center distance correction amount according to the actual light transmittance deviation; An output limiting module limits the center distance correction amount within a center distance correction amount limiting range to avoid etching line breakage caused by sudden change of the center distance; A frequency control module calculates a corrected center distance according to the initial center distance and the limited center distance correction amount, and adjusts the laser emission frequency of the galvanometer scanning module according to the corrected center distance and the actual speed.

2. The thin film solar cell etch light transmission dynamic control system of claim 1, wherein, The preset speed of the motion platform module is 200-800 mm / s, and the preset direction is the Y-axis direction, wherein the overall feeding direction of the motion platform module is defined as the Y-axis direction, and the vertical direction of the overall feeding direction of the motion platform module in the horizontal plane is the X-axis direction.

3. The thin film solar cell etch light transmission dynamic control system of claim 1, wherein, The laser beam emitted by the galvanometer scanning module has the following parameters: the wavelength of the laser beam is 1064 nm, the pulse width is picosecond to nanosecond, and the line width of the laser beam is 10-50 μm; the laser beam penetrates the back electrode layer and the absorption layer of the thin-film solar cell substrate without damaging the transparent conductive oxide layer.

4. The thin film solar cell etch light transmission dynamic control system of claim 1, wherein, The center distance correction amount limiting range is ±20 μm.

5. The thin film solar cell etch light transmission dynamic control system of claim 1, wherein, The light transmittance deviation threshold is 2%-4%.

6. The thin film solar cell etch light transmission dynamic control system of claim 1, wherein, Further comprising: A motion synchronization control module, which comprises a platform encoder, a path planning unit and a PLC controller; the platform encoder collects displacement data of the motion platform module in real time and feeds back to the PLC controller, the displacement data including the actual speed and actual position of the thin-film solar cell; the path planning unit generates an array pattern of etching lines, and divides the thin-film solar cell substrate into a plurality of rectangular field units, and simultaneously generates a continuous snakelike path of galvanometer scanning for each rectangular field unit; The PLC controller triggers the galvanometer scanning module to control the laser beam to perform linear gradient adjustment etching line marking on both sides of the splicing boundary of adjacent rectangular field units.

7. A method for dynamically controlling the etch transmittance of thin-film solar cells, characterized in that, The method is applied to the thin-film solar cell etching light transmittance dynamic control system of any one of claims 1-6, and the method comprises the following steps: S1: fixing the thin-film solar cell substrate on the motion platform module; S2: the motion platform module continuously moves the thin-film solar cell substrate at a constant speed in the value range of the preset speed in the Y-axis direction; S3: start the galvanometer scanning module, the galvanometer scanning module emits a laser beam to the surface of the thin-film solar cell substrate to form parallelly arranged etching lines; S4: the actual speed of the motion platform module is collected in real time by the speed sensor in the light transmittance control unit; S5: the center distance between adjacent etching lines of the galvanometer scanning module is adjusted in real time by the PID adjusting unit in the light transmittance control unit according to the target light transmittance preset value and the actual speed to maintain the deviation of the target light transmittance within the light transmittance deviation threshold.

8. The method of claim 7, wherein the etching rate is dynamically controlled by the light transmittance of the thin film solar cell. The step of adjusting the center distance between adjacent etching lines of the galvanometer scanning module in real time by the PID adjusting unit in the light transmittance control unit according to the target light transmittance preset value and the actual speed to maintain the deviation of the target light transmittance within the light transmittance deviation threshold comprises: S50: the initial center distance is calculated by the path planning unit according to the target light transmittance preset value and the line width of the laser beam; S51: the center distance correction of adjacent etching lines is calculated in real time by the PID adjusting unit according to the target light transmittance preset value and the actual speed; The corrected center distance is calculated according to the initial center distance and the center distance correction, the laser emission frequency of the galvanometer scanning module is adjusted according to the corrected center distance and the actual speed, and the laser beam performs etching of the next etching line according to the corrected center distance and the adjusted laser emission frequency to maintain the deviation of the actual light transmittance from the target light transmittance within the light transmittance deviation threshold.

9. The method of claim 8, wherein the etching rate is dynamically controlled by the light transmittance of the thin film solar cell. The step of adjusting the laser emission frequency of the galvanometer scanning module according to the corrected center distance and the actual speed comprises: The laser frequency adjusting module adjusts the laser emission frequency of the galvanometer scanning module in real time according to the corrected center distance d and the actual speed v through the formula f=v / d, wherein the value range of the corrected center distance d is 50-200μm, the value range of the actual speed v is 200-800mm / s, the adjustment range of the laser emission frequency f is 1-4kHz, and the adjustment response delay is ≤10μs, so as to maintain the deviation of the target light transmittance ≤3%.

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