CN220591880U

CN220591880U - Laser welding device

Info

Publication number: CN220591880U
Application number: CN202321409254.XU
Authority: CN
Inventors: 段雨飞; 程晓伟; 梁乔春; 陈登
Original assignee: Wuhan DR Llaser Technology Corp Ltd
Current assignee: Wuhan DR Llaser Technology Corp Ltd
Priority date: 2023-06-02
Filing date: 2023-06-02
Publication date: 2024-03-15
Anticipated expiration: 2033-06-02

Abstract

The application provides a laser welding device, include: the laser, the beam splitting module, the fine adjustment module, the laser scanning module and the processing plane are positioned on the same optical axis, and the processing element is arranged on the processing plane. The beam splitting module is used for splitting the laser beam to form a plurality of beam splitting beams so as to realize simultaneous welding of a plurality of welding spots. And the beam splitting module is also used for adjusting the arrangement direction of the light spots of the plurality of beam splitting beams on the processing element, so that the arrangement direction of the light spots of the beam splitting beams is the same as the arrangement direction of welding spots, and the influence of distortion generated in the process of transmitting the beam splitting beams to the welding spots due to large beam splitting angles on the welding effect is reduced. The fine adjustment module is used for adjusting the distance between the light spots formed by the plurality of beam splitting light beams on the processing element, so that the distance between the light spots on the processing element is the same as the distance between the welding spots, and then accurate welding of the processing element is facilitated.

Description

Laser welding device

Technical Field

The application relates to the technical field of laser processing, in particular to a laser welding device.

Background

The laser welding technology is often used for welding solar cells, a laser welding device for welding photovoltaic cells is configured to scan a scanning vibrating mirror for laser scanning, but single-beam laser welding is mostly adopted, and the working efficiency is low. The multi-beam laser welding device is based on a technical scheme of small spacing and multiple light paths, and cannot realize better welding on photovoltaic cells with large spacing and specific welding spots. Therefore, it is important to those skilled in the art to provide a laser welding apparatus for photovoltaic cells that corresponds to a large pitch solder joint.

Disclosure of Invention

In view of this, the present application provides a laser welding apparatus, which comprises the following steps:

a laser welding apparatus for laser welding a processing element, comprising: the laser, the beam splitting module, the fine tuning module, the laser scanning module and the processing plane are positioned on the same optical axis and are sequentially arranged, and the processing element is arranged on the processing plane when welding is carried out;

the laser generates a laser beam;

the beam splitting module is positioned on the transmission path of the laser beam, splits the laser beam to form a plurality of beam splitting beams, and adjusts the arrangement direction of light spots formed by the beam splitting beams on the processing element;

the fine adjustment module is positioned on the transmission path of the split light beams and used for adjusting the intervals among light spots formed by the multiple split light beams on the processing element;

the laser scanning module is positioned on the transmission path of the beam splitting beam, controls the transmission direction of the beam splitting beam and controls the movement of the beam splitting beam on the processing element so as to weld the processing element.

Optionally, after the plurality of split beams are formed by the beam splitting module, before being transmitted to the fine tuning module, an included angle between two adjacent split beams in the plurality of split beams is a first included angle; after the plurality of split light beams pass through the fine adjustment module, the included angle among the plurality of split light beams is a second included angle;

Wherein the second included angle is x times of the first included angle, and x is more than or equal to 0.8 and less than or equal to 1.2.

Optionally, the beam splitting module includes a beam splitter and a first motor;

the beam splitter is positioned on the transmission path of the laser beam and splits the laser beam to form a plurality of split beams;

the first motor drives the beam splitter to rotate, and the arrangement direction of light spots formed by the plurality of beam splitting light beams on the processing element is adjusted.

Optionally, the beam splitter is a diffractive light splitting element.

Optionally, the fine tuning module includes a fixed lens group, a first moving lens group, a second motor and a third motor, the second motor is connected with the first moving lens group, the third motor is connected with the second moving lens group, and the split beam is sequentially transmitted through the fixed lens group, the first moving lens group and the second moving lens group;

the second motor drives the first movable lens group to move along the optical axis, and the third motor drives the second movable lens group to move along the optical axis, so that the distance between light spots formed on the processing element by the plurality of split light beams is adjusted;

The third motor also drives the second movable lens group to move along the optical axis so as to maintain the divergence angle of the plurality of split light beams unchanged.

Optionally, the welding device further includes a camera, the camera is located above the processing plane, the plurality of split beams are transmitted to one side of the processing plane above the processing plane, and the camera is respectively connected with the first motor, the second motor and the third motor, so as to obtain spot position information formed by the plurality of split beams on the processing element, and generate a first driving signal and/or a second driving signal based on the spot position information;

the first motor drives the beam splitter to rotate based on the first driving signal, and the second motor and the third motor drive the first movable lens group and the second movable lens group to move based on the second driving signal.

Optionally, the laser is an optical fiber laser, the welding device further includes a shaping optical fiber, one end of the shaping optical fiber is connected with a light outlet of the laser, the other end corresponds to the beam splitting module, and the laser beam is transmitted to the beam splitting module through the shaping optical fiber;

Or, the welding device further comprises a diffraction shaping element for shaping the laser beam, the diffraction shaping element is located between the laser and the beam splitting module, and the laser beam is transmitted to the beam splitting module through the diffraction shaping element.

Optionally, the diameter of the shaping optical fiber is 50 μm to 600 μm, and the NA of the shaping optical fiber is 0.05 to 0.30.

Optionally, the laser scanning module includes along scanning galvanometer and the field lens that the transmission path of beam splitting set gradually, scanning galvanometer control beam splitting's direction of transmission and control beam splitting's removal on the processing component, the field lens is located scanning galvanometer's light-emitting side, focusing the beam splitting.

Optionally, the welding device further includes a collimating element, where the collimating element is located between the laser and the beam splitting module, and collimates the laser beam.

Compared with the prior art, the beneficial effects of the technical scheme of the application are as follows:

the laser welding device that this application provided includes: the laser, the beam splitting module, the fine tuning module, the laser scanning module and the processing plane are located on the same optical axis and are sequentially arranged, and when welding work is carried out, the processing element is placed on the processing plane. The beam splitting module is used for splitting the laser beam to form a plurality of beam splitting beams, so that simultaneous welding of a plurality of welding spots is realized, welding efficiency is improved, the beam splitting module also adjusts the arrangement direction of light spots formed by the beam splitting beams on the processing element, the arrangement direction of the light spots on the beam splitting beam processing element is the same as the arrangement direction of the welding spots on the processing element, and the influence of distortion generated in the process of transmitting the beam splitting beams to the welding spots due to large beam splitting angles on welding effects is reduced. The fine adjustment module is used for adjusting the distance between the light spots formed by the plurality of beam splitting light beams on the processing element, so that the distance between the light spots on the processing element is the same as the distance between the welding spots, and then accurate welding of the processing element is facilitated. The laser scanning module is used for controlling the transmission direction of the split light beam and the movement of the split light beam on the processing element so as to realize the welding of the processing element.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the related art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is apparent that the drawings in the following description are only embodiments of the present application, and other drawings may be obtained according to the provided drawings without inventive effort to those skilled in the art.

The structures, proportions, sizes, etc. shown in the drawings are shown only in connection with the present disclosure, and should not be construed as limiting the scope of the invention, since any modification, variation in proportions, or adjustment of the size, which would otherwise be used by those skilled in the art, would not have the essential significance of the present disclosure, would not affect the efficacy or otherwise be achieved, and would still fall within the scope of the present disclosure.

FIG. 1 is a schematic diagram of distortion of a spot formed on a machining plane by a welding beam in the prior art;

fig. 2 is a schematic structural diagram of a laser welding device provided in the present application;

FIG. 3 is a plot of the beam spot profile of a beam splitting beam on a processing element for a laser welding apparatus provided herein;

Fig. 4 is a schematic view of a first included angle A1 and a second included angle A2;

FIG. 5 is a schematic view of another laser welding apparatus provided in the present application;

fig. 6 is a schematic structural diagram of a trimming module in a laser welding apparatus provided in the present application;

FIG. 7 is a plot of the spot profile of a light beam when the first motor and the second motor are stationary;

fig. 8 is a schematic diagram of spot position information of a light beam when the first motor, the second motor and the third electrode drive the beam splitter, the first moving lens group and the second moving lens group respectively.

Detailed Description

Embodiments of the present application will now be described more fully hereinafter with reference to the accompanying drawings, in which it is shown, and in which it is evident that the embodiments described are exemplary only of one area of the application, and not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

In order that the above-recited objects, features and advantages of the present application will become more readily apparent, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings.

As described in the background section, it is important to those skilled in the art to provide a laser welding apparatus for photovoltaic cells that corresponds to large pitch solder joints.

The inventor researches and discovers that most photovoltaic laser welding devices with scanning galvanometers adopt single-beam laser processing, the processing efficiency is not high enough, and the industrial requirements are not met. The multi-beam laser processing device is based on a technical scheme of small spacing and multiple light paths, and cannot achieve a good laser processing effect for a photovoltaic cell with a large-spacing welding spot with a large welding spot spacing.

In addition, for the photovoltaic cell with the large-pitch welding spot, when the multi-beam welding is performed, in order to adapt to the large pitch, when the beam splitting of the laser beam is performed, a larger beam splitting angle is required to be adopted for beam splitting to form a plurality of laser beams, and the larger beam splitting angle can cause distortion in the process that the plurality of laser beams formed by beam splitting are transmitted to the welding spot on the photovoltaic cell. As shown in fig. 1, the distribution manner of the solder points 001 on the photovoltaic cell is generally horizontal and/or vertical distribution on the soldering plane, and when the distance between the solder points 001 is larger, the beam splitting angle of the laser beam during beam splitting is larger when the distance between the solder points 001 is larger, so that the beam transmission is distorted, the light spots 002 formed on the soldering plane by the light beam are not distributed along the horizontal direction or the vertical direction any more, the distribution directions of the light spots 002 and the solder points 001 are different, and the deviation exists, so that the light spots 002 cannot accurately solder the solder points 001 of the cell. The distortion is more serious at the edge position of the welding plane.

In summary, for photovoltaic cells with large pitch solder joints, it is important to provide a soldering apparatus that can achieve higher efficiency and greater accuracy.

Based on this, the present application provides a laser welding apparatus for laser welding a processing element 100, where the processing element 100 may be an element such as a photovoltaic cell that needs to be laser welded. As shown in fig. 2, fig. 2 is a schematic structural diagram of a laser welding apparatus provided in the present application, where the laser welding apparatus includes: the laser 10, the beam splitting module 20, the fine tuning module 30, the laser scanning module 40 and the processing plane 50 are located on the same optical axis and are sequentially arranged, and when the welding device performs welding work, the processing element 100 is placed on the processing plane 50. The laser 10, the beam splitting module 20, the trimming module 30, the laser scanning module 40 and the processing plane 50 are located on the same optical axis, which means that the centers of the laser 10, the beam splitting module 20, the trimming module 30, the laser scanning module 40 and the processing plane 50 are located on the same optical axis.

The laser 10 is used to generate a laser beam. Alternatively, in one embodiment of the present application, the laser 10 is a high power fiber laser, but the present application is not limited thereto, as the case may be.

The beam splitting module 20 is located on the transmission path of the laser beam, and the laser 10 and the beam splitting module 20 are sequentially arranged along the transmission direction of the laser beam. The beam splitting module 20 is configured to split the laser beam to form a plurality of split beams, and adjust an arrangement direction of light spots formed by the plurality of split beams on the processing element 100.

The fine tuning module 30 is located on the transmission path of the split beam, and the beam splitting module 20 and the fine tuning module 30 are sequentially arranged along the transmission direction of the split beam. The trimming module 30 is used to adjust the pitch between the spots of the split beam formed on the processing element 100.

The laser scanning module 40 is located on the transmission path of the split beam, and the fine tuning module 30 and the laser scanning module 40 are sequentially arranged along the transmission direction of the split beam. The laser scanning module 40 controls the transmission direction of the split beam and controls the movement of the split beam on the processing element 100 to weld the processing element. Specifically, the laser scanning module 40 is configured to control a transmission direction of the split beam so that the split beam is transmitted towards a direction where the processing element 100 is located, and is further configured to control movement of the split beam on the processing element 100, and further control a position of a light spot formed by the split beam on the processing element 100, so as to control high-speed switching of the split beam between welding spots on the processing element 100, that is, perform laser scanning on the welding spots on the processing element 100, thereby realizing welding of the photovoltaic cell. The laser scanning module 40 controls the split beam to move on the processing element 100, that is, the photovoltaic cell, and specifically, the laser scanning module 400 is controlled by software to perform laser beam scanning of the welding spot at the desired welding position.

Specifically, in the embodiment of the present application, the beam splitting module 20 in the laser welding device may split the laser beam into multiple split beams by one laser beam, so that simultaneous welding of multiple welding spots on the processing element 100 may be realized, and welding efficiency is improved. And the beam splitting module 20 can also adjust the arrangement direction of the light spots formed by the multiple beam splitting beams on the processing element 100, so that the arrangement direction of the light spots of the beam splitting beams on the processing element 100 can be the same as the arrangement direction of the welding spots on the processing element 100, thereby reducing the problem of transmission distortion of the beam splitting beams caused by large welding spot spacing, simultaneously enabling the light spots on the processing element 100 to be matched with the welding spots, and being beneficial to realizing accurate welding of the processing element 100. The beam splitting module 20 is located before the laser scanning module 40, that is, when the laser welding apparatus is operated, the laser beam is split first, and then the split beam formed by the splitting is transmitted to the processing element 100 through the laser scanning module 40, so as to weld the processing element 100. Therefore, the welding device can change parameters such as the beam splitting angle, the beam splitting quantity and the like of the beam formed after beam splitting by replacing the beam splitting module 20 so as to be suitable for welding of different processing elements 100, so that the flexibility and applicability of the laser welding device are stronger.

In addition, it should be noted that, since the intervals between the spots of the split beam formed by the beam splitting module 20 at different positions of the processing element 100 cannot be guaranteed to be completely uniform, there may be a slight deviation between the spot pitch formed on the split beam processing element 100 and the spot pitch of the processing element 100. Therefore, the laser welding device includes the fine tuning module 30, and the fine tuning module 30 can adjust the distance between the light spots formed on the processing element 100 by the split light beam, so that the distance between the light spots formed on the processing element 100 by the split light beam is the same as the welding spot distance, and further can be more accurately matched with the welding spot on the processing element 100, thereby being beneficial to realizing accurate welding of the processing element.

It should be noted that, the beam splitting module 20 and the fine tuning module 30 in the laser welding device are used for adjusting the position of the beam splitting beam irradiated on the processing element 100, specifically, the beam splitting module 20 splits the beam and simultaneously adjusts the arrangement direction of the light spots on the processing element 100, so that the arrangement direction of the light spots is the same as the arrangement direction of the welding spots, and meanwhile, the distance between the light spots is the same as the distance between the light spots as much as possible through the adjustment and control of the beam splitting angle. The fine tuning module 30 is used for fine tuning the beam splitting angle, so as to fine tune the spot spacing, and make the spot spacing identical to the solder joint spacing. Therefore, the beam splitting module 20 and the fine tuning module 30 are used for precisely matching the light spot of the split beam with the welding spot group to be welded on the processing element 100, so as to realize precise welding of the processing element. The laser scanning module 40 is configured to control the transmission direction of the split beam and the movement of the split beam, so that the split beam is transmitted to a processing position on the processing element 100, and after the welding of the current welding spot set is completed, the split beam is controlled to move to the next welding spot set, and so on.

It should be further noted that, the beam splitting module 20 and the fine tuning module 30 implement adjustment of the arrangement direction of the light spots on the processing element 100 and the distance between the light spots, so that the light spot group formed by the beam splitting light beam on the processing element 100 is matched with the welding spot group to be welded in a one-to-one correspondence manner, specifically, as shown in fig. 3, for example, when the welding spot group 110 arranged in the vertical direction on the processing element 100 is welded, the beam splitting module 20 and the fine tuning module 30 are used for adjusting the position of the beam splitting light beam irradiated on the processing element 100, so that the light spot group 120 formed by the beam splitting light beam on the processing element 100 is arranged in the vertical direction, and the distance between the light spots is the same as the distance between the welding spots, so as to implement welding with the welding spot accurate matching.

In one embodiment of the present application, as shown in fig. 4, fig. 4 is a schematic diagram of a first included angle A1 and a second included angle A2, after the plurality of split beams are split by the beam splitting module 20, and before being transmitted between the fine tuning modules 30, that is, after the plurality of split beams are split by the beam splitting module 20 and before being adjusted by the fine tuning module 30, an included angle between two adjacent split beams in the plurality of split beams is the first included angle A1, and after the split beams are passed by the fine tuning module 30, that is, after the split beams are adjusted by the fine tuning module 30, an included angle between two adjacent split beams in the plurality of split beams is the second included angle A2. Wherein, the second included angle A2 is x times of the first included angle A1, and x is more than or equal to 0.8 and less than or equal to 1.2. It can be seen that the trimming module 30 can change the beam splitting angle between the split beams such that the beam splitting angle of the split beam is changed from the first included angle to the second included angle. The second included angle is known to be 0.8-1.2 times of the first included angle, so that the fine adjustment module 30 can achieve fine adjustment of the beam splitting angle of the split beam, fine adjustment of the spot spacing formed on the processing element 100 by the second split beam is achieved, the spot spacing formed on the processing element 100 by the split beam is identical to the spot spacing, and the split beam can be more accurately matched with the spot spacing on the processing element 100, so that accurate welding of the processing element is facilitated. It should be noted that, before the plurality of split beams pass through the beam splitting module 20 and are transmitted to the fine tuning module 20, the angles between two adjacent split beams in the plurality of split beams may not be identical according to the number of split beams, and there is a very small deviation, and the characteristics are determined by the splitter 21 in the beam splitting module 20, for example, the DOE, and in this embodiment, the influence caused by the deviation of the angles between two adjacent split beams may be temporarily ignored.

In an embodiment of the present application, as shown in fig. 5, fig. 5 is a schematic structural diagram of a laser welding device provided in the present application, where the beam splitting module 20 includes a beam splitter 21 and a first motor 22, the beam splitter 21 is located on a transmission path of a laser beam, specifically, the laser 10 and the beam splitter 21 are sequentially arranged along a transmission direction of the laser beam, and are located between the laser 10 and the fine tuning module 20, and split the laser beam to form the multiple beam splitting beams. The first motor 22 is a rotating motor, and is configured to drive the beam splitter 21 to rotate, so as to adjust the arrangement direction of the light spots formed by the split light beams on the processing element 100, so that the arrangement direction of the light spots formed by the multiple split light beams on the processing element 100 is the same as the arrangement direction of the welding spots to be welded, for example, the light spots are arranged along the horizontal direction or the vertical direction, which is helpful for realizing accurate welding of the processing element 100. It should be noted that, the horizontal direction and the vertical direction are parallel to the plane of the solder joint of the processing element 100, and the horizontal direction and the vertical direction are perpendicular to each other.

Alternatively, based on the above embodiment, in one embodiment of the present application, the beam splitter 21 is a diffractive beam splitting element, which is also referred to as a beam splitting DOE, so that a larger beam splitting distance can be implemented, so that the laser welding apparatus can be suitable for welding a photovoltaic cell with a large-pitch welding spot. And the beam-splitting DOE can be flexibly disassembled, so that when the laser welding device welds different processing elements 100, the proper beam-splitting DOE can be correspondingly replaced according to the difference of the processing elements 100, thereby ensuring the precision of laser welding.

In one embodiment of the present application, the beam splitter 21 is a one-dimensional tri-beam DOE, but the present application is not limited thereto, and in other embodiments of the present application, the beam splitter 21 may be a one-dimensional 4-beam splitter, a one-dimensional 5-beam splitter, or the like, and may form a two-dimensional laser beam splitting matrix for superposition of two one-dimensional beam splitting DOEs. In addition, according to the polarization characteristics of the fiber laser, the beam splitter 21 may be a beam splitter element including a half-wave plate and a PBS (Polarization Beam Splitter, polarization splitting prism), and the beam splitter element may be rotated to uniformly split one beam into two beams, and the two beams may be split into 4 beams, or the like until the requirements are satisfied.

On the basis that the beam splitting module 20 comprises a beam splitter 21 and a first motor 22, in one embodiment of the present application, as shown in fig. 5 and 6, fig. 6 is a schematic structural diagram of a fine tuning module, where the fine tuning module 30 is an electric zoom beam expander and includes a fixed lens group 31, a first moving lens group 32, a second moving lens group 33, a second motor 34 and a third motor 35, the second motor 34 is connected with the first moving lens group 32, the third motor 35 is connected with the second moving lens group 33, the beam splitting beam is sequentially transmitted through the fixed lens group 31, the first moving lens group 32 and the second moving lens group 33, and the fixed lens group 31, the first moving lens group 32 and the second moving lens group 33 are sequentially located between the beam splitter 21 and the laser scanning module 40. The second motor 34 and the third motor 35 are translation motors or linear motors, the second motor 34 is used for driving the first moving lens 32 to move along the optical axis, changing the distance between the first moving lens group 32 and the fixed lens group 31, and the third motor 35 is used for driving the second moving lens group 33 to move along the optical axis, changing the distance between the second moving lens group 34 and the fixed lens group 31, so as to adjust the distance between the light spots formed by the plurality of beam splitting beams on the processing element 100. The third motor 35 further drives the second moving lens group to move along the optical axis, so as to change the distance between the second moving lens group and the fixed lens group, so as to maintain the divergence angle of the plurality of split light beams unchanged.

Specifically, the second motor 34 drives the first moving lens group 32 to move, so as to change the distance between the first moving lens group 32 and the fixed lens group 31, and the second motor 35 drives the second moving lens group 33 to move along the optical axis, so that after changing the distance between the second moving lens group 34 and the fixed lens group 31, the focal length of the whole of the fixed lens group 31, the first moving lens group 32 and the second moving lens group 33 is changed, and therefore, the beam splitting angle of the beam splitting beam passing through the first moving lens group 32 is changed, so as to achieve the purpose of adjusting the spot pitches formed by the beam splitting beams on the processing element 100. Therefore, by changing the distances between the first movable lens group 32 and the second movable lens group 33 and the fixed lens group 31 by using the second motor 34 and the third motor 35, the splitting angle of the split beam is further changed, so as to realize fine adjustment of the split beam, and the spot pitches of the split beams formed on the processing element 100 are adjusted, so that accurate welding of the photovoltaic cell is realized.

Also, when the beam splitting angle of the beam splitting beam is changed, the divergence angle of the beam splitting beam may be changed. Therefore, the third motor 35 is further configured to drive the second moving lens group 33 to move along the optical axis, change the distance between the second moving lens and the fixed lens group 31, and compensate the divergence angle while adjusting the beam splitting angle of the split beam, so that the fine tuning module 30 can maintain the divergence angle unchanged while changing the beam splitting angle of the split beam, thereby forming the split beam with slightly changed beam splitting angle and unchanged divergence angle. In addition, in the process of compensating the divergence angle so that the divergence angle is unchanged, in order not to affect the beam splitting angle of the adjusted beam splitting beam, the movement degree of the third motor 35 driving the second moving lens group 33 should be very small, and the movement should be performed without affecting the beam splitting angle.

On the basis of the above embodiment, in one embodiment of the present application, as further shown in fig. 5, the welding device further includes a camera 60, where the camera 60 is located above the processing plane 50, and the above of the processing plane 50 is that the plurality of split beams are transmitted to one side of the processing plane 50, that is, the above of the processing plane 50 corresponds to the side of the processing plane 50 where the processing element 100 is located. And the camera is connected to the first motor 22, the second motor and the third motor 35, respectively, and the camera 60 is configured to obtain spot position information of the split beam on the processing element 100, and generate a first driving signal and/or a second driving signal based on the obtained spot position information. The first motor 22 drives the beam splitter 21 to rotate based on the first driving signal, the second motor 34 and the third motor 35 drive the first moving lens group 32 and the second moving lens group 33 to move along the optical axis based on the second driving signal, specifically, the second motor drives the first moving lens group 32 to move along the optical axis based on the second driving signal, and the third motor 35 drives the second moving lens group 33 to move along the optical axis based on the second driving signal. The camera 60 is located above the processing plane 50, specifically, the camera 60 is located directly above the processing plane 50, but is not located on the transmission path of the split beam.

Specifically, in this embodiment of the present application, after the camera 60 obtains the spot position information of the split beam on the processing element 100, the camera 60 analyzes the deviation between the spot arrangement direction of the split beam and the arrangement direction of the welding spots of the processing element 100 and the deviation between the spot spacing of the split beam and the welding spots by using the obtained spot position information, if no deviation exists, the camera 60 does not output a driving signal to the first motor and the second motor, if deviation exists, the camera 60 generates a first driving signal and/or a second driving signal based on the deviation result, and sends the first driving signal and/or the second driving signal to the corresponding first motor 22, the second motor 34 and the third motor 35, so that the first motor 22, the second motor 34 and the third motor 35 perform corresponding driving operations to regulate the arrangement direction of the spots on the processing element 100 and the spot spacing, thereby realizing accurate welding of the processing element 100. When the deviation between the arrangement direction of the light spots of the split light beam and the arrangement direction of the welding spots of the processing element 100 is analyzed based on the spot position information acquired by the camera 60, the analysis may be performed based on the welding spot distribution map of the processing element 100 acquired in advance and the spot position information acquired by the camera 60, or the analysis may be performed based on the spot position information acquired by the camera 60 and the welding spot position information of the processing element 100 acquired at the same time, as the case may be.

It should be further noted that, when the processing element 100 is subjected to laser welding, the arrangement direction of the light spots on the processing element 100 and the distance between the light spots may need to be adjusted at the same time, or only one of them may need to be adjusted, that is, the beam splitting module 20 and the fine tuning module 30 do not necessarily need to adjust the light beams at the same time, so when the camera 60 generates the driving signals, the first driving signal and the second driving signal may be generated at the same time based on the obtained position information of the light spots, or only the first driving signal or the second driving signal may be generated, which is specific to the practical situation.

In addition, when the laser welding apparatus welds the processing element 100, the trimming module 30 may adjust both the beam splitting angle and the divergence angle of the split beam, or may adjust only the beam splitting angle. The second motor 34 and the third motor 35 adjust the first moving lens group 32 and the second moving lens group 33 based on the second driving signal, or the second motor 34 and the third motor 35 adjust the first moving lens group 32 and the second moving lens group 33 based on the second driving signal, and then the third motor 35 drives the second moving lens group 33 again. Specifically, when the beam splitting angle and the divergence angle need to be adjusted simultaneously, the second motor 34 and the third motor 35 drive the first moving lens group 32 to move and the second moving lens group 33 to move based on the second driving signal, and after the beam splitting angle is adjusted, the third motor 35 drives the second moving lens group 33 to move. When only the beam splitting angle is adjusted, the second motor 34 and the third motor 35 drive the first moving lens group 32 and the second moving lens group 33 to move based on the second driving signal. It should be noted that, when the second motor 34 and the third motor 35 drive the first moving lens group 32 and the second moving lens group 33 to move based on the second driving signal, the moving sequence of the first moving lens group 32 and the second moving lens group 33 is not limited in this application, and the first moving lens group 32 may be driven to move first, or the second moving lens group 33 may be driven to move first, according to the situation.

In one embodiment of the present application, continuing to refer to fig. 5, the laser scanning module 40 includes a scanning galvanometer 41 and a field lens 42 (T-Theta field lens) sequentially disposed on a transmission path of the split beam, where the scanning galvanometer 41 is configured to control a transmission direction of the split beam, and control a movement of the split beam on the processing element 100, so that the split beam is transmitted to the processing element 100, and the split beam is made to fully act on the processing element 100, and meanwhile, the split beam is also made to switch between different welding spot groups at a high speed. The field lens 42 is located at the light emitting side of the scanning galvanometer 41, and is configured to focus the split beam, so as to ensure uniformity of a light spot irradiated on the processing element 100 by the split beam, and further make the split beam uniformly strike on the processing element 100, and weld the processing element 100.

Based on the above embodiments, in one embodiment of the present application, as further shown in fig. 5, the scanning galvanometer 41 includes a light incident surface and a light emergent surface, where the light incident surface is opposite to the light emergent side of the fine adjustment module 30, and when the fine adjustment module 30 includes the fixed lens group 31, the first moving lens group 32 and the second moving lens group 33, the light incident surface of the scanning galvanometer 41 is opposite to the light emergent surface of the second moving lens group 33.

It should be noted that, when the beam splitter 21 is a DOE laser beam splitter, the beam splitting angle thereof can be obtained according to the beam splitting angle of the pitch between the pads. According to the formula: (f) ₁ +Δf)×tan(θ ₁ ) D, where d is the spacing between spots on the processing element 100, f ₁ For the focal length of the scanning galvanometer 41 in the laser scanning module 40, Δf is the sum of the defocus amount of the plane in which the weld spot of the processing element 100 lies and the distance between the scanning galvanometer 41 and the principal plane of the field lens 42. As known from the above formula, the pitch of the spots on the processing element 100 and the beam splitting angle θ of the DOE laser beam splitter ₁ Related to the following. Since the final objective is to make the spot spacing on the processing element 100 the same as the spacing between the welding spots, d in the above formula can be set as the distance between the welding spots, and the above formula can be used to calculate the beam splitting angle θ when the DOE laser beam splitter splits ₁ Then the beam splitting angle is selected to be theta ₁ Is a DOE of (c).

In one embodiment of the present application, as further shown in fig. 5, on the basis that the laser 10 is a fiber laser, the welding device further includes a shaping optical fiber 71, where the shaping optical fiber 71 is located between the laser 10 and the beam splitting module 20, one end of the shaping optical fiber 71 is connected to the light outlet of the laser 10, and the other end of the shaping optical fiber is opposite to the light incident surface of the collimating lens 72 and extends along the transmission direction of the laser beam, and the laser beam is transmitted to the beam splitting module 20 through the shaping optical fiber 71. The shaping fiber 71 is used for shaping the laser beam, specifically, shaping the spot of the laser beam, so that the shape of the spot formed by the spectroscopic beam on the processing element 100 can be controlled.

Specifically, in this embodiment of the present application, one end of the shaping optical fiber 71 is connected to the light outlet of the laser 10, so that the laser beam can be transmitted through the shaping optical fiber 71, so that the spot shape of the laser beam can be adjusted, and further, the spot shape of the split beam is controlled, so that the spot on the processing element 100 is identical to the shape of the welding spot of the processing element 100, and further, the shape of the welding spot and the shape of the welding spot for realizing welding are matched, and the welding quality is improved.

Optionally, in an embodiment of the present application, the shaping optical fiber 71 adjusts a spot shape of the laser beam, so that the spot shape of the laser beam is square. The diameter of the shaping fiber 71 is 50 μm to 600 μm, and the NA of the shaping fiber is: NA is from 0.05 to 0.30, and characterizes the ability of the fiber to collect light. Preferably, the diameter of the shaping fiber 71 is, for example, 50 μm or 100 μm or 150 μm or 200 μm, preferably 50 μm, so that the diameter of the spot eventually formed on the processing element 100 is approximately 1.3mm or so, which can be matched to the solder joint size of the photovoltaic cell.

The type and size of the shaped optical fiber 71 are not limited in the present application, and the shaped optical fiber may be shaped in other shapes to match the shape of the solder joint, and the diameter of the optical fiber may be other values, as the case may be.

In another embodiment of the present application, the welding device further comprises a diffractive shaping element, which is located between the laser and the beam splitting module, through which the laser beam is transmitted to the beam splitting module, the diffractive shaping element also being referred to as a shaping DOE, to shape the laser beam such that the beam splitting beam forms a spot of the same shape as the spot of welding on the processing element 100.

In one embodiment of the present application, the laser welding apparatus further includes a collimating element 72, where the collimating element 72 is located between the laser 10 and the beam splitting module 20, and is used for collimating the laser beam, enhancing the directionality of the laser beam, and more concentrating energy of the beam splitting beam, so that the energy of the beam splitting beam is more concentrated, which is beneficial for efficient welding of the processing element 100.

On the basis of the above embodiment, when the laser welding apparatus includes a shaping optical fiber, as shown in fig. 5, the collimating element 72 is located between the shaping optical fiber 71 and the beam splitting module 20, and the laser beam is sequentially transmitted to the beam splitting module 20 through the shaping optical fiber 71 and the collimating element 72.

When the laser welding device comprises a shaping DOE, the collimating element is positioned between the diffraction shaping element and the beam splitting module, and the laser beam is sequentially transmitted to the beam splitting module through the diffraction shaping element and the collimating element.

Alternatively, in one embodiment of the present application, the collimating element 72 is a focusing lens. And when the collimating element 72 is a focusing lens, the size of the light spot on the processing element 100 can be continuously adjusted by an out-of-focus method so as to adapt to welding spots with different sizes.

As shown in fig. 7 and 8, fig. 7 illustrates spot position information of the split beam on the processing element 100 when the first motor 22 does not drive the beam splitter 21 to rotate, and the second motor 34 and the third motor 35 do not drive the first moving lens group 32 and the second moving lens group 33 to translate, fig. 8 illustrates spot position information of the split beam on the processing element 100 when the first motor 22 drives the beam splitter 21 to rotate, and the second motor 34 and the third motor 35 drive the first moving lens group 32 and the second moving lens group 33 to translate, wherein fig. 7 and 8 take the laser beam divided into three laser beams as an example, and each group of spots has three spots. As can be seen from comparing fig. 7 and 8, when the first motor 22 and the second motor 34 are stationary, the three light spots in the light spot group at the edge of the processing element 100 deviate by at most about 1 °, and the uniformity of the distance between the adjacent light spots in each group of light spots is poor, which seriously affects the welding accuracy of the laser welding. After the movement adjustment of the first motor 22 and the second motor 34, the position deviation of the light spots in each light spot group on the processing element 100 is not more than 0.15 ° at maximum, and is far less than 1 °, and the distance between adjacent light spots in each group of light spots is about 14mm, so that the uniformity of the distance between the light spots is greatly improved. Therefore, in the laser welding device, the beam splitter 21 is driven by the first motor 22 to rotate to compensate the distortion of the beam splitting beam, and the first moving lens group 32 and the second moving lens group 33 are driven by the second motor 34 to translate to finely adjust the beam splitting angle, so that the light spot is precisely matched with the welding spot.

In summary, the laser welding device can accurately adjust the position and the size of a light spot of a welding beam on a processing element, so that the light spot and the welding spot are accurately matched, and further, the photovoltaic cell is accurately welded.

The specific operation of the laser welding apparatus provided in the present application will be described in detail.

Taking the example that the laser welding device comprises a shaping optical fiber, the control software of the upper computer controls the laser 10 to emit laser beams, the laser beams are transmitted to the shaping optical fiber 71, and the shaping optical fiber 71 shapes Gaussian light spots into square light spots. The shaped laser beam is transmitted to the collimating element 72 through the shaping optical fiber 71, the collimating element 72 collimates the laser beam, and the distance between the collimating element 72 and the light outlet of the shaping optical fiber 71 is adjusted to adjust the divergence angle of the laser beam. After passing through the collimating lens, the laser beam is transmitted to the beam splitting module 20, and is uniformly split by the beam splitter 21 of the beam splitting module 20 to form a plurality of split beams, and meanwhile, the beam splitter 21 is driven to rotate by the first motor 22, and the arrangement direction of the light spots on the processing element 100 is adjusted, so that the arrangement direction of the light spots is the same as the arrangement direction of the welding spots. The split beam formed by splitting is transmitted to the fine adjustment module 30, so that fine adjustment of the splitting angle of the split beam is realized, and the spot pitch on the processing element 100 is the same as the welding spot pitch. Finally, the split beam is transmitted to the processing element 100 under the control of the scanning galvanometer 41, and is focused by the field lens 42, so that welding is performed.

It should be noted that, after each time the beam splitter beam is transmitted to the processing element 100, the camera 60 obtains the spot position information of the beam splitter beam, then determines the deviation between the arrangement direction of the spots on the processing element 100 and the arrangement direction of the welding spots, and the deviation between the spot spacing and the welding spot spacing, and generates the first driving signal and/or the second driving signal, so as to implement feedback adjustment of the beam splitter module 20 and the fine adjustment module 30, so that the arrangement direction of the spots on the processing element 100 is the same as the arrangement direction of the welding spots, and the spot spacing is the same as the welding spot spacing, and further, the spots of the beam splitter beam on the processing element 100 are precisely matched with the welding spots of the processing element 100.

In summary, the present application provides a laser welding apparatus, including: the laser device, the beam splitting module, the fine adjustment module, the laser scanning module and the processing plane are located on the same optical axis and are sequentially arranged, and when welding work is carried out, the processing element is placed on the processing plane. The beam splitting module is used for splitting the laser beam to form a plurality of beam splitting beams so as to realize simultaneous welding of a plurality of welding spots, improve welding efficiency, and adjust arrangement direction sections of light spots formed by the beam splitting beams on the processing element, so that the arrangement direction of the light spots formed on the processing element is the same as the arrangement direction of the welding spots on the processing element, and the arrangement direction of the light spots on the processing element and the arrangement direction of the welding spots caused by distortion generated in the transmission process of the beam splitting beams are different. The fine adjustment module is used for adjusting the distance between the light spots formed by the plurality of beam splitting light beams on the processing element, so that the distance between the light spots on the processing element is the same as the distance between the welding spots, and then accurate welding of the processing element is facilitated. The laser scanning module is used for controlling the split light beam to realize the welding of the processing element.

In the present specification, each embodiment is described in a progressive manner, or a parallel manner, or a combination of progressive and parallel manners, and each embodiment is mainly described as different from other embodiments, and the same similar areas between the embodiments are referred to each other. For the device disclosed in the embodiment, since the device corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method area.

It should be noted that, in the description of the present application, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific direction, be configured and operated in the specific direction, and thus should not be construed as limiting the present application. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

It is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such article or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in an article or apparatus that comprises such element.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A laser welding apparatus for laser welding a processing element, comprising: the laser, the beam splitting module, the fine tuning module, the laser scanning module and the processing plane are positioned on the same optical axis and are sequentially arranged, and the processing element is arranged on the processing plane when welding is carried out;

the laser generates a laser beam;

2. The welding device of claim 1, wherein an included angle between two adjacent split light beams in the plurality of split light beams is a first included angle after the plurality of split light beams are formed by the beam splitting module and before the plurality of split light beams are transmitted to the fine tuning module; after the plurality of split light beams pass through the fine adjustment module, the included angle among the plurality of split light beams is a second included angle;

3. The welding device of claim 1, wherein the beam splitting module comprises a beam splitter and a first motor;

4. A welding device as defined in claim 3, wherein said beam splitter is a diffractive beam splitting element.

5. The welding apparatus of claim 3 wherein the fine tuning module comprises a fixed lens group, a first moving lens group, a second motor, and a third motor, the second motor being coupled to the first moving lens group, the third motor being coupled to the second moving lens group, the split beam being transmitted sequentially through the fixed lens group, the first moving lens group, and the second moving lens group;

6. The welding device of claim 5, further comprising a camera positioned above the machining plane, wherein the plurality of split beams are transmitted to one side of the machining plane above the machining plane, and wherein the camera is respectively connected to the first motor, the second motor, and the third motor, acquires spot position information formed by the plurality of split beams on the machining element, and generates a first driving signal and/or a second driving signal based on the spot position information;

7. The welding device according to claim 1, wherein the laser is an optical fiber laser, the welding device further comprises a shaping optical fiber, one end of the shaping optical fiber is connected with a light outlet of the laser, the other end of the shaping optical fiber corresponds to the beam splitting module, and the laser beam is transmitted to the beam splitting module through the shaping optical fiber;

8. The welding device as defined in claim 7, wherein the diameter of the shaping fiber is 50 μm to 600 μm, and the NA of the shaping fiber is 0.05 to 0.30.

9. The welding device of claim 1, wherein the laser scanning module comprises a scanning galvanometer and a field lens sequentially arranged along a transmission path of the split beam, the scanning galvanometer controlling a transmission direction of the split beam and controlling movement of the split beam on the processing element, the field lens being located on an outgoing side of the scanning galvanometer to focus the split beam.

10. The welding device of claim 1, further comprising a collimating element positioned between the laser and the beam splitting module to collimate the laser beam.