Laser slotting processing system and processing method thereof

Abstract

The present invention relates to a laser grooving processing system and a processing method thereof. The laser grooving processing system comprises: a laser grooving processing device, which is used to perform grooving processing on a battery cell transmitted to a laser grooving station; a film thickness detection device is arranged upstream of the laser grooving processing device, which is used to detect the film thickness of the battery cell before being transmitted to the laser grooving station; and a laser control device is electrically connected to the film thickness detection device and the laser grooving processing device, respectively. On a battery with high film thickness, an increase in power is bound to lead to a corresponding increase in light spots. The original tangent light spots will become intersecting light spots. Repeated grooving areas will cause serious surface damage, resulting in low efficiency. Reducing the frequency can eliminate this effect. On a battery with low film thickness, although the reduction in power will reduce the diffraction range and corrosion width, it will inevitably reduce the laser opening rate. By increasing the laser frequency, the corresponding back aluminum electrode and silicon contact are met, and a good transmission effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of solar cell sheet processing technology, and in particular to a laser grooving processing system and a processing method thereof. Background Art

[0002] In the photovoltaic industry, PERC cells are manufactured by using passivation dielectric films Al2O3 and SiN to protect the dangling bonds on the back surface of the cell, forming a fixed electric field and producing a passivation effect, thereby reducing surface recombination and improving cell efficiency. At the same time, since the silicon wafer surface contains unsaturated dangling bonds formed by the interruption of the periodic arrangement of the atomic structure, space charges and surface potential barriers are generated on the surface and interface of the crystal structure, forming an unstable surface state, which affects the normal transport of carriers. Therefore, PERC cells need to use a laser grooving process to make the aluminum back field form a local point contact with the silicon wafer to reduce the contact between the metal back electrode and the back surface, thereby increasing the open circuit voltage.

[0003] In the process of manufacturing the back passivation film structure by ALD and PECVD deposition, the actual gas flow rate, butterfly valve opening, actual temperature of the furnace area and other conditions in different furnace tubes are generally different, which will lead to the extreme difference of the structure and thickness of the passivated film layer after deposition within ±20nm, which is actually 80-120nm. The existing process is to use a unified fixed laser slotting power to correspond to slotting lasers with different passivation film thicknesses, which will bring the following problems: 1. The slotting laser energy is fixed, that is, the power of the same machine is consistent when slotting cells with different film thicknesses, resulting in abnormal spot morphology after slotting of cells outside the film thickness deviation range, and low cell efficiency; 2. For cells with high film thickness, the existing laser slotting energy is insufficient under the fixed power, and the spot size and morphology are abnormal, and irregular morphology appears at the edge of the spot; 3. For cells with low film thickness, the existing laser slotting power is easy to directly penetrate the passivation layer on the surface of the cell, with a large diffraction range, a large corrosion width after sintering, and damage to the silicon substrate, resulting in low cell efficiency. Summary of the invention

[0004] Based on this, it is necessary to provide a laser grooving processing system and a processing method thereof, aiming to solve the problem that the grooving laser processing energy in the prior art cannot be flexibly adapted to battery cells with different film thicknesses, resulting in poor processing quality.

[0005] In one aspect, the present application provides a laser slotting processing system, comprising:

[0006] Laser slotting processing equipment, used to perform slotting processing on the battery cells transmitted to the laser slotting station;

[0007] A film thickness detection device, which is disposed upstream of the laser slotting processing device and is used to detect the film thickness of the battery cell before it is introduced into the laser slotting station; and

[0008] A laser control device is electrically connected to the film thickness detection device and the laser grooving processing device respectively.

[0009] When the laser slotting processing system of the above scheme is working, the battery cells flow on the conveyor line to pass through different processing stations. Since a film thickness detection device is equipped upstream of the laser slotting processing equipment, when the battery cell after the passivation treatment is moved to the film thickness detection device, it can first be subjected to film thickness detection by the film thickness detection device to obtain the back passivation film thickness value of the current battery cell, and then the detected film thickness value is transmitted to the laser control device, and then the laser control device can control the laser slotting processing equipment to correspond to different film thicknesses, adjust and set different slotting laser powers and frequencies, so that each battery cell can obtain the best energy for laser slotting. High film thickness reduces the probability of abnormal light spots and irregular edge morphology through this design. Low film thickness can also reduce the diffraction range after slotting, reduce the corrosion width, and reduce damage to the film structure. On high film thickness batteries, the increase in power will inevitably lead to a corresponding increase in light spots. The original tangent light spots will become intersecting light spots. Repeated slotting areas cause serious surface damage, resulting in low efficiency. Reducing the frequency can eliminate this effect. In low-thickness batteries, although the reduction in power will reduce the diffraction range and corrosion width, it will inevitably reduce the laser opening rate. By increasing the laser frequency and meeting the corresponding back aluminum electrode and silicon contact, a good transmission effect can be achieved.

[0010] The technical solution of this application is further described below:

[0011] In one embodiment, the film thickness detection device includes a film thickness acquisition camera and a film thickness image processor, the film thickness acquisition camera is used to capture the film layer image of the battery cell, the film thickness acquisition camera is electrically connected to the film thickness image processor, and the film thickness image processor is electrically connected to the laser control device.

[0012] In one of the embodiments, the film thickness detection device further includes an adjustment bracket, and the film thickness acquisition camera is installed in the processing site through the adjustment bracket.

[0013] In one of the embodiments, the adjustment bracket includes an adjustment seat, a lifting assembly and a carrier, the carrier is installed on the adjustment seat through the lifting assembly, and the film thickness acquisition camera is arranged on the carrier.

[0014] In one of the embodiments, the adjustment bracket further includes a rotation driver and a rotating frame, the rotation driver is disposed on the carrier, the rotating frame is drivingly connected to the rotation driver, and the film thickness acquisition camera is disposed on the rotating frame.

[0015] In one embodiment, the laser grooving processing system also includes a film color detection device and a screening execution device, the film color detection device is electrically connected to the screening execution device, and the film color detection device is arranged upstream or downstream of the film thickness detection device, or the film color detection device and the film thickness detection device are arranged side by side, and the film color detection device is arranged upstream of the laser grooving processing device.

[0016] In one embodiment, the film color detection device comprises a film color detection probe and a film color detection bracket, and the film color detection probe is arranged on the film color detection bracket; or

[0017] The film color detection device comprises a film color detection probe, a fill light and a film color detection bracket, and the film color detection probe and the fill light are respectively arranged on the film color detection bracket.

[0018] In one of the embodiments, the screening execution device includes a mounting seat, a flexible robotic arm and a grasping unit, wherein the flexible robotic arm is disposed on the mounting seat, and the grasping unit is connected to a distal end of the flexible robotic arm.

[0019] In one of the embodiments, the gripping unit includes a carrier plate and a suction cup, and the suction cup is disposed on the carrier plate.

[0020] On the other hand, the present application also provides a processing method using the above-mentioned laser slotting processing system, which comprises the following steps:

[0021] The battery cell undergoes film thickness testing by film thickness testing equipment;

[0022] The film thickness detection device transmits the detected film thickness data to the laser control device, and the laser control device calls the laser processing parameters matching the film thickness value of the current cell and transmits them to the laser slotting processing device;

[0023] The battery cell is moved to a slotting station, and the laser slotting equipment performs laser slotting on the battery cell.

[0024] Since a film thickness detection device is installed upstream of the laser grooving processing equipment, when the cell after passivation treatment moves to the film thickness detection device, it can first be subjected to film thickness detection by the film thickness detection device to obtain the back passivation film thickness value of the current cell, and then the detected film thickness value is transmitted to the laser control device, and then the laser control device can control the laser grooving processing equipment to correspond to different film thicknesses, adjust and set different grooving laser powers and frequencies, so that each cell can obtain the best energy for laser grooving. High film thickness reduces the probability of abnormal light spots and irregular edge morphology through this design. Low film thickness can also reduce the diffraction range after grooving, reduce the corrosion width, and reduce damage to the film structure. On high film thickness cells, an increase in power will inevitably lead to a corresponding increase in light spots. The original tangent light spots will become intersecting light spots. Repeated grooving areas will cause serious surface damage, resulting in low efficiency. Reducing the frequency can eliminate this effect. In low-thickness batteries, although the reduction in power will reduce the diffraction range and corrosion width, it will inevitably reduce the laser opening rate. By increasing the laser frequency and meeting the corresponding back aluminum electrode and silicon contact, a good transmission effect can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 This is a simplified structural diagram of the laser slotting processing system in this application;

[0028] Figure 2 This is a flowchart of the steps of the processing method of the laser grooving processing system in this application.

[0029] Description of reference numerals:

[0030] 10. Laser slotting processing equipment; 20. Film thickness detection equipment; 30. Laser control equipment; 40. Film color detection equipment; 50. Screening execution equipment; 60. Cell passivation; 70. Cell printing. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0032] like Figure 1 FIG. 1 is a block diagram of a laser slotting system according to an embodiment of the present application, which includes: a laser slotting device 10, a film thickness detection device 20, and a laser control device 30. Compared with the traditional laser slotting system, this solution adds a film thickness detection process.

[0033] Specifically, the laser grooving processing equipment 10 is used to perform grooving processing on the battery cell transmitted to the laser grooving station; the film thickness detection equipment 20 is arranged upstream of the laser grooving processing equipment 10, and is used to detect the film thickness of the battery cell before it is transmitted to the laser grooving station; the laser control equipment 30 is electrically connected to the film thickness detection equipment 20 and the laser grooving processing equipment 10 respectively.

[0034] It can be understood that the laser slotting processing system also includes a conveyor line, which can be any one of a pulley conveyor line, a chain plate conveyor line, etc., for automatically moving the battery cells to the downstream slotting station after the battery cell passivation 60 treatment is completed.

[0035] In summary, the implementation of the technical solution of this embodiment will have the following beneficial effects: when the laser slotting processing system of the above solution is working, the battery cells flow on the conveyor line to pass through different processing stations. Since a film thickness detection device 20 is provided upstream of the laser slotting processing device 10, when the cell after the passivation treatment is moved to the film thickness detection device 20, it can first be subjected to film thickness detection by the film thickness detection device 20, so as to obtain the back passivation film thickness value of the current cell, and then the detected film thickness value is transmitted to the laser control device 30, and then the laser control device 30 can control the laser slotting processing device 10 to correspond to different film thicknesses, adjust and set different slotting laser powers and frequencies, so that each cell can obtain the best energy for laser slotting. High film thickness reduces the probability of abnormal light spots and irregular edge morphology through this design. Low film thickness can also reduce the diffraction range after slotting, reduce the corrosion width, and reduce the damage to the film structure. On high film thickness cells, an increase in power will inevitably lead to a corresponding increase in light spots. The original tangent light spots will become intersecting light spots. Repeated slotting areas will cause serious surface damage, resulting in low efficiency. Reducing the frequency can eliminate this effect. In low-thickness batteries, although the reduction in power will reduce the diffraction range and corrosion width, it will inevitably reduce the laser opening rate. By increasing the laser frequency and meeting the corresponding back aluminum electrode and silicon contact, a good transmission effect can be achieved.

[0036] In other words, when the thickness of the back passivation film of the battery cell is small, the laser control device 30 can control the laser grooving processing equipment 10 to perform grooving processing with a corresponding smaller power and frequency; on the contrary, when the thickness of the back passivation film of the battery cell is large, the laser control device 30 can adjust the laser grooving processing equipment 10 to perform grooving processing with a corresponding larger power and frequency.

[0037] In some embodiments, the film thickness detection device 20 includes a film thickness acquisition camera and a film thickness image processor, wherein the film thickness acquisition camera is used to capture the film layer image of the cell, the film thickness acquisition camera is electrically connected to the film thickness image processor, and the film thickness image processor is electrically connected to the laser control device 30. When the cell enters the film thickness detection station, the film thickness acquisition camera can capture the image of the current cell and transmit the image to the film thickness image processor, which can obtain the back passivation film thickness value of the current cell by optical detection principle and comparison with standard data in the database, and then can feed back the film thickness value to the laser control device 30, so as to control the laser slotting processing device 10 to perform laser slotting processing on the cell with appropriate parameters.

[0038] Furthermore, the film thickness detection device 20 also includes an adjustment bracket, and the film thickness acquisition camera is installed in the processing site through the adjustment bracket. According to different working site conditions and different specifications of battery cells, the height and angle of the film thickness acquisition camera can be flexibly adjusted by operating the adjustment bracket so that the battery cell image can be clearly captured.

[0039] Specifically, in some embodiments, the adjustment bracket includes an adjustment seat, a lifting assembly and a carrier, the carrier is installed on the adjustment seat through the lifting assembly, and the film thickness acquisition camera is arranged on the carrier. When the lifting assembly is operated, the carrier can be lifted and lowered relative to the adjustment seat, so as to achieve the purpose of flexibly adjusting the height of the film thickness acquisition camera. The structural composition and adjustment method are simple and the operability is strong.

[0040] Optionally, the lifting assembly may be, but is not limited to, any one of a motor screw slider assembly, a scissors mechanism, a counterweight mechanism, and the like.

[0041] Furthermore, the adjustment bracket further includes a rotary driver and a rotating frame, wherein the rotary driver is disposed on the carrier, the rotating frame is drivingly connected to the rotary driver, and the film thickness acquisition camera is disposed on the rotating frame. The rotary driver drives the rotating frame to rotate clockwise or counterclockwise, so as to flexibly adjust the shooting angle of the film thickness acquisition camera, and facilitate the capture of image data of different parts of the battery cell.

[0042] Optionally, the rotary drive may be a rotary cylinder, or a combination of a motor and a reversing assembly, which may be selected according to actual needs.

[0043] Please continue reading Figure 1 In addition, based on any of the above embodiments, the laser grooving processing system also includes a film color detection device 40 and a screening execution device 50, the film color detection device 40 is electrically connected to the screening execution device 50, and the film color detection device 40 is arranged upstream or downstream of the film thickness detection device 20, or the film color detection device 40 and the film thickness detection device 20 are arranged side by side, and the film color detection device 40 is arranged upstream of the laser grooving processing equipment 10.

[0044] The film color detection device 40 can identify the battery cells with appearance quality defects after passivation processing, so that the screening execution device 50 can remove the defective battery cells from the production line, reduce the transmission of defective battery cells and affect the smooth progress of the rear-end laser grooving processing, and avoid unnecessary waste of processing resources.

[0045] Specifically, in some embodiments, the film color detection device 40 includes a film color detection probe and a film color detection bracket, and the film color detection probe is arranged on the film color detection bracket. The film color detection bracket is used to support the film color detection probe to a suitable height position above the battery cell. The film color detection probe takes an appearance image of the battery cell and analyzes the image to determine whether there is an appearance quality defect.

[0046] Alternatively, as an alternative to the above implementation, the film color detection device 40 includes a film color detection probe, a fill light, and a film color detection bracket, and the film color detection probe and the fill light are respectively arranged on the film color detection bracket. The difference from the above solution is that the present embodiment is equipped with a fill light, which can be turned on in places or time periods with poor light conditions to enhance light, ensuring that the film color detection probe can capture a clear image of the battery cell, so as to more accurately determine whether there are appearance quality defects.

[0047] Optionally, the fill light can be any one of switch control, sound control, etc. and the fill light can be any one of LED lamp, incandescent lamp, fluorescent lamp, etc.

[0048] It can be understood that the membrane color detection bracket can adopt the same structure and working principle as the above-mentioned adjustment bracket, so it is not described here in detail.

[0049] In some embodiments, the screening execution device 50 includes a mounting seat, a flexible mechanical arm and a grabbing unit, wherein the flexible mechanical arm is arranged on the mounting seat, and the grabbing unit is connected to the end of the flexible mechanical arm. The mounting seat realizes the loading support of the flexible mechanical arm, and the flexible mechanical arm has multiple linear and rotational degrees of freedom, which can drive the grabbing unit to accurately land on the surface of the defective battery cell, so as to accurately grab the defective battery cell and remove it from the production line.

[0050] Specifically, in the above embodiment, the gripping unit includes a carrier plate and a suction cup, and the suction cup is arranged on the carrier plate. The carrier plate is mounted on the fixed suction cup, and the suction cup is tightly pressed against the surface of the battery cell to generate negative pressure suction, so that the defective battery cell can be firmly grasped so as to be removed from the production line. The use of the adsorption gripping method can avoid the battery cell from being subjected to physical clamping force, thereby preventing secondary damage to the battery cell.

[0051] Of course, it should be noted that in other embodiments, the grabbing unit may also use bonding, magnetic attraction, lifting and other methods to achieve the operation of picking up and placing the defective battery cells.

[0052] like Figure 2 As shown above, in addition to the above, the present application also provides a processing method using the above laser slotting processing system, which includes the following steps:

[0053] S100 : The battery cell undergoes film thickness inspection by the film thickness inspection device 20 .

[0054] S200 : the film thickness detection device 20 transmits the detected film thickness data to the laser control device 30 , and the laser control device 30 calls the laser processing parameters matching the film thickness value of the current cell and transmits them to the laser grooving processing device 10 .

[0055] S300: The battery cell is moved to a slotting station, and the laser slotting processing equipment 10 performs laser slotting processing on the battery cell.

[0056] It should be noted that the battery cell after the laser grooving process will further flow into the printing station to receive the battery cell printing 70 process, and then undergo the sintering process, so as to obtain the finished battery cell.

[0057] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0059] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0060] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0061] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0063] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

Claims

1. A laser slotting processing system, characterized in that: include: Laser slotting processing equipment, used to perform slotting processing on the battery cells transmitted to the laser slotting station; A film thickness detection device, which is arranged upstream of the laser slotting processing device and is used to detect the film thickness of the battery cell before it is introduced into the laser slotting station; as well as A laser control device, wherein the laser control device is electrically connected to the film thickness detection device and the laser slotting processing device respectively; The film thickness detection device includes a film thickness acquisition camera and a film thickness image processor. The film thickness acquisition camera is used to capture the film layer image of the battery cell. The film thickness acquisition camera is electrically connected to the film thickness image processor, and the film thickness image processor is electrically connected to the laser control device.

2. The laser slotting processing system according to claim 1, characterized in that: The film thickness detection device also includes an adjustment bracket, and the film thickness acquisition camera is installed in the processing site through the adjustment bracket.

3. The laser slotting processing system according to claim 2, characterized in that: The adjustment bracket comprises an adjustment seat, a lifting assembly and a carrier, the carrier is installed on the adjustment seat through the lifting assembly, and the film thickness acquisition camera is arranged on the carrier.

4. The laser slotting processing system according to claim 3, characterized in that: The adjustment bracket also includes a rotation driver and a rotating frame. The rotation driver is arranged on the carrier. The rotating frame is drivingly connected to the rotation driver. The film thickness acquisition camera is arranged on the rotating frame.

5. The laser slotting processing system according to claim 1, characterized in that: The laser grooving processing system also includes a film color detection device and a screening execution device, the film color detection device is electrically connected to the screening execution device, and the film color detection device is arranged upstream or downstream of the film thickness detection device, or the film color detection device and the film thickness detection device are arranged side by side, and the film color detection device is arranged upstream of the laser grooving processing device.

6. The laser slotting processing system according to claim 5, characterized in that: The film color detection device comprises a film color detection probe and a film color detection bracket, and the film color detection probe is arranged on the film color detection bracket.

7. The laser slotting processing system according to claim 5, characterized in that: The film color detection device comprises a film color detection probe, a fill light and a film color detection bracket, and the film color detection probe and the fill light are respectively arranged on the film color detection bracket.

8. The laser slotting processing system according to claim 5, characterized in that: The screening execution device comprises a mounting seat, a flexible mechanical arm and a grasping unit. The flexible mechanical arm is arranged on the mounting seat, and the grasping unit is connected to the end of the flexible mechanical arm.

9. The laser slotting processing system according to claim 8, characterized in that: The grabbing unit comprises a carrier plate and a suction cup, and the suction cup is arranged on the carrier plate.

10. A processing method using the laser slotting processing system according to any one of claims 1 to 9, characterized in that: The steps include: The battery cell undergoes film thickness testing by film thickness testing equipment; The film thickness detection device transmits the detected film thickness data to the laser control device, and the laser control device calls the laser processing parameters matching the film thickness value of the current cell and transmits them to the laser slotting processing device; The battery cell is moved to a slotting station, and the laser slotting equipment performs laser slotting on the battery cell.

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