Laser scribing and transfer apparatus and method for processing thin film solar cells

Abstract

This invention belongs to the field of thin-film solar cell fabrication technology, and discloses a laser scribing and transfer device and its method for processing thin-film solar cells. The device includes a laser, a processing head, a processing platform, and a motion control mechanism. The processing head includes a beam splitting mechanism, a laser scribing output port, a laser transfer output port, and a transfer mechanism. This invention integrates laser scribing and transfer into one device, and the laser scribing output port and the laser transfer output port are aligned in the movement direction of the processing head. During processing, the scribing and transfer paths completely overlap, thereby completing the printing of insulating material for the groove simultaneously with the scribing process, without increasing the dead zone width of the module. The process is simple, with high filling accuracy and low equipment cost. This invention uses laser transfer to cover insulating material on the groove, which is less expensive than dispensing equipment and requires less photoresist and other insulating adhesives.

Description

Technical Field

[0001] This invention belongs to the field of thin-film solar cell fabrication technology, and particularly relates to a laser scribing and transfer device and a method for processing thin-film solar cells. Background Technology

[0002] In thin-film solar cells, common inline technology involves three grooves: P1, P2, and P3. The P1 groove is typically formed before the light-absorbing layer is deposited, usually using laser cutting. The light-absorbing layer is then prepared after the P1 groove is formed. The main purpose of the P1 groove is to divide the module into small, mutually insulating regions. This requires that the material within the P1 groove be insulating; otherwise, the insulation of the P1 groove will not meet the requirements, resulting in a low parallel resistance and low efficiency for the module.

[0003] In cadmium telluride thin-film solar cells, the P1 grooves are formed after the light-absorbing layer has been prepared. Negative photoresist is filled into the P1 grooves, and after the photoresist cures, the P2 grooves are formed. This process significantly improves the fill factor of the module, primarily due to the increased parallel resistance. This groove-filling photoresist process is complex, often employing fine dispensing techniques. The dispensing equipment is expensive, and real-time monitoring of the P1 grooves is required.

[0004] When selecting the conductive hole or electron transport layer for perovskite solar cells, the P1 scribe line should be placed after the perovskite light-absorbing layer has been prepared. This can result in a higher fill factor and module efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a laser scribing and transfer device and a method for processing thin-film solar cells, which can simultaneously perform P1 scribing on thin-film solar cells and fill insulating adhesive, thereby reducing equipment costs and improving the processing efficiency of thin-film solar cells.

[0006] This invention provides a laser scribing and transfer device, comprising a laser, a processing head, a processing platform, and a motion control mechanism. The laser emits laser light to the processing head, the processing platform holds the thin-film solar cell to be processed, and the motion control mechanism drives the processing head to move along a predetermined path directly above the processing platform. The processing head includes a beam splitting mechanism, a laser scribing output port, a laser transfer output port, and a transfer mechanism. The laser scribing output port and the laser transfer output port are aligned in the direction of movement of the processing head. The beam splitting mechanism divides the laser beam entering the processing head into laser branches that are directed towards the laser scribing output port and the laser transfer output port, respectively. The laser scribing output port faces the processing platform to project the laser onto the thin-film solar cell to form grooves. The transfer mechanism conveys a coating tape with an insulating material attached. The laser transfer output port faces the coating tape, and the laser emitted from the laser transfer output port irradiates the insulating material on the coating tape, transferring the insulating material into the grooves of the thin-film solar cell.

[0007] Furthermore, the laser scribing and transfer equipment also includes a collimating beam expander connected between the laser and the processing head, which is used to convert the laser beam emitted from the laser into a collimated beam.

[0008] Furthermore, the beam splitting mechanism includes a first beam splitting lens, which is used to split the laser beam entering the processing head into a first branch laser beam emitted to the laser engraving light output port and a second branch laser beam emitted to the laser transfer light output port.

[0009] Furthermore, the beam splitting mechanism also includes a second beam splitting lens, a third beam splitting lens, a first laser power meter, and a second laser power meter; the second beam splitting lens is used to split the first branch laser beam into two paths, one of which is directed towards the laser engraving output port, and the other is directed towards the first laser power meter; the third beam splitting lens is used to split the second branch laser beam into two paths, one of which is directed towards the laser transfer output port, and the other is directed towards the second laser power meter.

[0010] Furthermore, the beam splitting mechanism also includes a first laser attenuator and a second laser attenuator, wherein the first laser attenuator is located between the first beam splitting lens and the second beam splitting lens; and the second laser attenuator is located between the first beam splitting lens and the third beam splitting lens.

[0011] Furthermore, the processing head also includes a first focusing lens, a first focusing lens up-and-down moving mechanism, a second focusing lens, and a first focusing lens up-and-down moving mechanism; the first focusing lens is located between the second beam-splitting lens and the laser engraving light outlet, and the first focusing lens up-and-down moving mechanism is used to drive the first focusing lens up and down to achieve laser focus adjustment; the second focusing lens is located between the third beam-splitting lens and the laser transfer light outlet, and the second focusing lens up-and-down moving mechanism is used to drive the second focusing lens up and down to achieve laser focus adjustment.

[0012] Furthermore, the processing head also includes an exhaust gas extraction device located at the bottom of the processing head, which is used to collect the exhaust gas of fumes and insulating adhesive generated during laser processing.

[0013] Furthermore, the laser engraving and transfer equipment also includes a gantry frame, which is vertically fixed above the processing platform. The motion control mechanism is mounted on the gantry frame, and the processing head is suspended on the gantry frame and connected to the power output end of the motion control mechanism. The processing head can reciprocate along the width direction of the gantry frame under the drive of the motion control mechanism.

[0014] To achieve the above-mentioned objectives, the present invention also provides a method for processing thin-film solar cells using the aforementioned laser scribing and transfer equipment, comprising the following steps: Step 1: Set the process parameters for the P1 groove of the thin-film solar cell to be processed, and at the same time set the process parameters for laser transfer. Step 2: After the thin-film solar cell to be processed enters the processing platform, the motion control mechanism drives the processing head to move along the set path. The laser scribing light outlet first enters the top of the thin-film solar cell and emits laser to process the P1 groove. Since the laser scribing light outlet and the laser transfer light outlet are aligned in the direction of movement of the processing head, the laser emitted from the laser transfer light outlet behind can cooperate with the transfer mechanism to transfer the insulating material into the P1 groove while the P1 groove is being processed. The transfer does not require positioning. Step 3: After the insulating adhesive is transferred and dried, the P1 cable tray is finally covered and insulated.

[0015] Further, repeat steps one through three to perform laser scribing of P3 grooves and transfer coating on the thin-film solar cell.

[0016] Compared with existing technologies, the laser scribing and transfer equipment of this invention integrates laser scribing and transfer into a single device. Furthermore, the laser scribing output port and the laser transfer output port are aligned in the direction of the processing head's movement. During processing, the scribing and insulating material transfer paths completely overlap, allowing the printing of insulating material into the groove to be completed simultaneously with the scribing process. This avoids increasing the dead zone width of the component. Compared to the two-step method, it eliminates the need for real-time P1 scribing during photoresist filling, resulting in a simpler process, higher filling accuracy, and lower equipment cost. On the other hand, this invention uses laser transfer to cover the insulating adhesive onto the groove. Compared to using precise dispensing equipment, this invention has a lower equipment cost and requires less photoresist and other insulating adhesives. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the structural principle of a laser engraving and transfer device provided in an embodiment of the present invention; Figure 2 yes Figure 1 A three-dimensional structural diagram of the intermediate machining head; Figure 3 yes Figure 2 The front view of the machining head is shown. Figure 4 This is a schematic diagram illustrating the principle of simultaneous laser engraving and transfer processing provided in an embodiment of the present invention; Figure 5 yes Figure 2 The diagram shows the internal structure of the processing head. Figure 6 This is a schematic diagram of the laser scribing and transfer equipment provided in the embodiments of the present invention for processing thin-film solar cells. Detailed Implementation

[0018] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0019] Please refer to Figure 1 As shown, this invention discloses a laser engraving and transfer device, comprising a laser 1, a collimating and expanding lens 2, a processing head 3, a processing platform 4, a motion control mechanism (not shown in the figure), and a gantry 5. The arrowed lines in the figure indicate the direction of movement of the laser beam.

[0020] The laser 1 is an ultraviolet picosecond or ultraviolet nanosecond laser (M2 < 1.3). A collimating beam expander 2 is connected between the laser 1 and the processing head 3 to amplify the laser beam emitted from the laser 1 and convert it into a collimated beam. The laser emitted from the laser 1 enters the entrance aperture of the processing head 3 after passing through the collimating beam expander 2 (which is four times larger). Throughout the processing, the laser 1 remains stationary, and laser transmission occurs via a flying optical path.

[0021] The processing platform 4 is used to place the thin-film solar cell A to be processed. A gantry frame 5 is vertically fixed above the processing platform 4. A motion control mechanism is mounted on the marble crossbeam of the gantry frame 5. The processing head 3 is suspended on the gantry frame 5 and is connected to the power output end of the motion control mechanism. Under the control and drive of the motion control mechanism, the processing head 3 can perform linear reciprocating motion along the width direction of the gantry frame 5. In this embodiment, the motion control mechanism uses a linear motor drive with air bearing, thereby ensuring the motion accuracy and stability of the processing head 3. In other embodiments, linear transmission mechanisms such as a servo motor and lead screw pair, or a servo motor and pulley assembly, can also be used.

[0022] Please also refer to Figure 2 and Figure 3 The processing head 3 includes a beam splitting mechanism, a laser marking exit port, a laser transfer exit port, and a transfer mechanism. The beam splitting mechanism divides the laser beam entering the processing head into laser branches that are directed towards the laser marking exit port and the laser transfer exit port, respectively. The laser marking exit port faces the processing platform 4, and the laser emitted from it can mark lines on the thin-film solar cell A placed on the processing platform 4. The transfer mechanism conveys a coating tape a with an insulating material attached. The laser transfer exit port faces the coating tape a, which is a transparent or light-transmitting tape, such as PET tape. The laser emitted from the laser transfer exit port irradiates the insulating material on the coating tape a, causing the insulating material to be transferred into the grooves of the thin-film solar cell A.

[0023] Specifically, the transfer mechanism includes two spaced-apart motors 31. One motor 31 has a unwinding roller 32 mounted on its shaft, and the other motor 31 has a take-up roller 33 mounted on its shaft. The two ends of the coating belt a are wound around the unwinding roller 32 and the take-up roller 33, respectively. Further details can be found in the following documents. Figure 4 In order to calculate the pull-out and rewind lengths of the coating belt a, metering rollers 30 for calculating the pull-out and rewind lengths of the coating belt a can be installed on the outer sides of the unwinding roller 32 and the rewinding roller 33, respectively.

[0024] Specifically, see Figure 5The beam splitting mechanism includes a first beam splitter lens 34a, a second beam splitter lens 34b, a third beam splitter lens 34c, a first laser power meter 35a, a second laser power meter 35b, a first laser attenuator 36a, and a second laser attenuator 36b. The first laser attenuator 36a is located between the first beam splitter lens 34a and the second beam splitter lens 34b. The second laser attenuator 36b is located between the first beam splitter lens 34a and the third beam splitter lens 34c. The first laser attenuator 36a and the second laser attenuator 36b are used to control the proportion of transmitted laser light, thereby adjusting the laser intensity. In this embodiment, the first beam splitter lens 34a, the second beam splitter lens 34b, and the third beam splitter lens 34c are all half-reflective half-lens using a half-wave plate.

[0025] The laser beam enters the processing head 3 through an entrance aperture on its side. A first beam splitter 34a splits the laser beam into a first branch and a second branch. The first branch laser beam's power is reduced after passing through a first laser attenuator 36a, and then it passes through a second beam splitter 34b, splitting into two branches. One branch's laser beam enters a first laser power meter 35a, which monitors the power of this laser beam in real time (the power of this laser beam is equal to the power of the scribing laser). The other branch's laser beam is directed towards the scribing exit port. The scribing exit port faces the processing platform 4, allowing scribing to be applied to the thin-film solar cell A on the processing platform 4. After passing through the second laser attenuator 36b, the power of the second branch laser beam is reduced. Then, it passes through the third beam splitter 34c and splits into two branches. The laser beam from one branch enters the second laser power meter 35b, which can monitor the power of the laser beam in real time (the power of the laser beam is equal to the power of the transfer laser). The laser beam from the other branch is directed towards the laser transfer output port to irradiate the insulating material on the coating tape a.

[0026] It should be noted that, for reference Figure 6 In this embodiment, the laser scribing light outlet and the laser transfer light outlet are aligned in the moving direction of the processing head 3. That is, the laser scribing light outlet and the laser transfer light outlet are coaxially arranged, and the center line connecting the two is parallel to the moving direction of the processing head.

[0027] For further information, please refer to [link / reference]. Figure 5The processing head 3 in this embodiment also includes a first focusing lens 37a, a first focusing lens up-and-down moving mechanism 37b, a second focusing lens 37c, and a second focusing lens up-and-down moving mechanism 37d. The first focusing lens 37a is located between the second beam-splitting lens 34b and the laser engraving output port. The first focusing lens up-and-down moving mechanism 37a is used to drive the first focusing lens 37a up and down to adjust the laser focus. The second focusing lens 37c is located between the third beam-splitting lens 34c and the laser transfer output port. The second focusing lens up-and-down moving mechanism 37d is used to drive the second focusing lens 37c up and down to adjust the laser focus. By designing the above-mentioned focus adjustment structure, the motion accuracy of the laser focus can be ensured to reach the nanometer level.

[0028] Furthermore, the processing head 3 in this embodiment also includes an exhaust gas extraction device 38, which is located at the bottom of the processing head 3 and is used to collect the exhaust gas of fumes and insulating adhesive generated during laser processing.

[0029] Please read again Figure 6 This embodiment also provides a method for processing thin-film solar cells using the above-mentioned laser scribing and transfer equipment, including the following steps: Step 1: Set the process parameters for the P1 groove of the thin-film solar cell A to be processed, and at the same time set the process parameters for laser transfer.

[0030] Step 2: After the thin-film solar cell A to be processed enters the processing platform 4, the motion control mechanism drives the processing head 3 to move along the set path. The laser scribing light outlet first enters above the thin-film solar cell A and emits laser to process the P1 groove. Since the laser scribing light outlet and the laser transfer light outlet are aligned in the direction of movement of the processing head, the laser emitted from the rear laser transfer light outlet can cooperate with the transfer mechanism to transfer the insulating adhesive (such as photoresist) into the P1 groove while the P1 groove is being processed. The transfer does not require positioning.

[0031] Step 3: After the insulating adhesive is transferred, it is dried at 80 degrees Celsius, and finally the P1 cable tray is covered and insulated.

[0032] Further, steps one through three are repeated to perform laser etching and adhesive transfer on the P3 grooves of the thin-film solar cell. P3 grooves are processed on the thin-film solar cell A, and simultaneously, an insulating adhesive layer is applied over the processed P3 grooves. This insulating adhesive layer prevents short circuits in the P3 grooves while also covering the exposed light-absorbing layer, preventing prolonged contact with air and subsequent decomposition. This method is particularly suitable for laser processing in the field of perovskite thin-film solar cells.

[0033] It should be noted that the insulating material mentioned above for laser transfer can be photoresist, or other insulating materials such as silicon oxide / silicon nitride that are soluble in organic solvents.

[0034] In summary, the laser engraving and transfer equipment and its application method provided in this embodiment have the following beneficial effects: First, laser scribing and transfer are integrated into one device, and the laser scribing output port and the laser transfer output port are aligned in the moving direction of the processing head 3. During processing, the scribing and the transfer path of the insulating material completely overlap, so that the printing of the insulating material of the groove can be completed at the same time as the scribing process. This does not increase the dead zone width of the component. Compared with the two-step method, it eliminates the step of real-time gripping of the P1 scribing during the photoresist filling process. The process is simple, the filling accuracy is high, and the equipment cost is low.

[0035] Second, this embodiment uses laser transfer to cover the insulating adhesive on the line groove. Compared with using a fine dispensing equipment, the equipment cost of this embodiment is lower, and the amount of photoresist and other insulating adhesives used is also less.

[0036] Third, both laser optical paths are equipped with real-time power monitoring, which can ensure process stability and improve the quality of thin-film solar cell A.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser scribing and transfer apparatus, characterized by, It includes a laser, a processing head, a processing platform, and a motion control mechanism; the laser is used to emit laser light to the processing head, the processing platform is used to place the thin-film solar cell to be processed, and the motion control mechanism is used to drive the processing head to move directly above the processing platform along a set path; The processing head includes a beam splitting mechanism, a laser scribing light output port, a laser transfer light output port, and a transfer mechanism; the laser scribing light output port and the laser transfer light output port are aligned in the moving direction of the processing head; the beam splitting mechanism is used to split the laser beam entering the processing head into laser branches that are directed towards the laser scribing light output port and the laser transfer light output port respectively; the laser scribing light output port faces the processing platform so as to project the laser onto the thin-film solar cell to form grooves; The transfer mechanism is used to convey a coating tape with an insulating material attached. The laser transfer output port faces the coating tape, and the laser emitted from the laser transfer output port irradiates the insulating material of the coating tape, so that the insulating material is transferred into the groove of the thin-film solar cell.

2. The laser scribing and transfer apparatus of claim 1, wherein, It also includes a collimating beam expander, which is connected between the laser and the processing head and is used to convert the laser beam emitted from the laser into a collimated beam.

3. The laser scribing and transfer apparatus of claim 1, wherein, The beam splitting mechanism includes a first beam splitting lens, which is used to split the laser beam entering the processing head into a first branch laser beam emitted to the laser engraving light output port and a second branch laser beam emitted to the laser transfer light output port.

4. The laser scribing and transfer apparatus of claim 3, wherein, The beam splitting mechanism further includes a second beam splitting lens, a third beam splitting lens, a first laser power meter, and a second laser power meter; the second beam splitting lens is used to split the first branch laser beam into two paths, one of which is directed towards the laser engraving output port, and the other is directed towards the first laser power meter; the third beam splitting lens is used to split the second branch laser beam into two paths, one of which is directed towards the laser transfer output port, and the other is directed towards the second laser power meter.

5. The laser scribing and transfer apparatus of claim 4, wherein, The beam splitting mechanism further includes a first laser attenuator and a second laser attenuator, wherein the first laser attenuator is located between the first beam splitting lens and the second beam splitting lens; and the second laser attenuator is located between the first beam splitting lens and the third beam splitting lens.

6. The laser scribing and transfer apparatus of claim 4, wherein, The processing head further includes a first focusing lens, a first focusing lens up-and-down moving mechanism, a second focusing lens, and a first focusing lens up-and-down moving mechanism; the first focusing lens is located between the second beam-splitting lens and the laser scribing light outlet, and the first focusing lens up-and-down moving mechanism is used to drive the first focusing lens up and down to achieve laser focus adjustment; the second focusing lens is located between the third beam-splitting lens and the laser transfer light outlet, and the second focusing lens up-and-down moving mechanism is used to drive the second focusing lens up and down to achieve laser focus adjustment.

7. The laser scribing and transfer apparatus of claim 1, wherein, The processing head also includes an exhaust gas extraction device located at the bottom of the processing head, which is used to collect the exhaust gas from the fumes and insulating adhesive generated during laser processing.

8. The laser scribing and transfer apparatus of claim 1, wherein, It also includes a gantry frame, which is vertically fixed above the processing platform. The motion control mechanism is mounted on the gantry frame, and the processing head is suspended on the gantry frame and connected to the power output end of the motion control mechanism. The processing head can reciprocate along the width direction of the gantry frame under the drive of the motion control mechanism.

9. A method of processing a thin film solar cell using the laser scribing and transfer apparatus according to any one of claims 1 to 8, characterized by, Includes the following steps: Step 1: Set the process parameters for the P1 groove of the thin-film solar cell to be processed, and at the same time set the process parameters for laser transfer. Step 2: After the thin-film solar cell to be processed enters the processing platform, the motion control mechanism drives the processing head to move along the set path. The laser scribing light outlet first enters the top of the thin-film solar cell and emits laser to process the P1 groove. Since the laser scribing light outlet and the laser transfer light outlet are aligned in the direction of movement of the processing head, the laser emitted from the laser transfer light outlet behind can cooperate with the transfer mechanism to transfer the insulating material into the P1 groove while the P1 groove is being processed. The transfer does not require positioning. Step 3: After the insulating adhesive is transferred and dried, the P1 cable tray is finally covered and insulated.

10. The method of claim 9, wherein, Repeat steps one through three to perform laser scribing of P3 grooves and transfer coating on the thin-film solar cell.

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