A laser welding device for BC battery busbar

Abstract

The utility model provides a kind of BC battery busbar laser welding device, comprising: laser composite head includes blue light laser assembly, infrared laser assembly and CCD component;Blue light laser assembly includes blue light lens, first reflector, second reflector;Infrared laser assembly includes infrared lens, third reflector, red blue composite lens;CCD component includes the CCD camera, CCD monitoring lens and fourth reflector that are sequentially arranged;Red blue composite laser emission source, and red blue composite laser emission source is connected with laser composite head by composite optical fiber;Processing platform, processing platform includes X-axis moving component, Y-axis moving component and processing table board.The utility model can be to several busbars and battery high-efficiency welding, uniformity is high, and welding effect is good, avoid build-up welding, blast hole, and yield is high, and efficiency is high and stability is strong.

Description

Technical Field

[0001] This utility model relates to the field of battery processing technology, and in particular to a laser welding device for BC battery busbars. Background Technology

[0002] Traditional BC battery welding of busbars mostly involves applying traditional contact welding or a single infrared laser system to the surface of the busbar workpiece. However, both of these methods have the following problems:

[0003] 1. Low work efficiency;

[0004] 2. Poor welding and a high rate of incomplete welds result in a low yield.

[0005] 3. Traditional infrared lasers do not absorb the busbar well, causing local overheating, damaging the passivation layer, and resulting in unstable welding effects. Utility Model Content

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a laser welding device for BC battery busbars. This invention can efficiently weld multiple busbars to the battery with high uniformity, good welding effect, avoid weld overlay and pore breakage, high yield, high efficiency and strong stability.

[0007] The embodiments of this utility model are achieved through the following technical solutions:

[0008] A laser welding device for BC battery busbars includes:

[0009] A laser composite head includes a blue laser component, an infrared laser component, and a CCD component; the CCD component and the infrared laser component are located on the left and right sides of the blue laser component, respectively; the blue laser component includes a blue lens, a first reflector, a second reflector, and a red-blue composite lens arranged sequentially along the output direction of the blue laser beam; the infrared laser component includes an infrared lens and a third reflector arranged sequentially along the output direction of the infrared laser beam; the CCD component includes a CCD camera, a CCD monitoring lens, and a fourth reflector arranged sequentially; the third reflector is located to the right of the second reflector, and the fourth reflector is located to the left of the first reflector;

[0010] A red-blue composite laser emission source is connected to the laser composite head via a composite optical fiber;

[0011] The processing platform includes an X-axis moving component for moving the laser composite head in the X-axis direction, a Y-axis moving component for moving the laser composite head in the Y-axis direction, and a processing table, wherein the X-axis moving component and the Y-axis moving component are disposed on the processing table.

[0012] According to a preferred embodiment, the red-blue composite laser emission source includes a plurality of red-blue composite lasers, each of the red-blue composite lasers corresponds to a laser composite head, and each of the red-blue composite lasers is connected to the corresponding laser composite head through a composite optical fiber.

[0013] According to a preferred embodiment, the blue laser beam wavelength is between 400nm and 500nm, and the infrared laser beam wavelength is between 800nm ​​and 1100nm.

[0014] According to a preferred embodiment, a laser nozzle is detachably connected to the lower end of the laser composite head, and a spring is connected between the lower end of the laser composite head and the laser nozzle.

[0015] According to a preferred embodiment, the device further includes a swing motor connected to the third reflector.

[0016] According to a preferred embodiment, both the blue laser beam and the infrared laser beam are coaxially output after passing through the red-blue composite lens.

[0017] A welding method for a BC battery busbar laser welding device includes the following steps:

[0018] Step S10: Place the glass backplate onto the processing platform.

[0019] Step S20: Place the battery cell string and EVA material on the glass backing plate, and adhere the copper foil to the EVA material;

[0020] Step S30: Adjust the position of the laser composite head by using the X-axis moving component and the Y-axis moving component, and adjust the output trajectory of the infrared laser beam by controlling the swing motor through the program, so as to control the coaxial output of the infrared laser beam and the blue laser beam;

[0021] Step S40: Weld the busbar onto the copper foil. First, preheat with blue light for T1 seconds, and then perform deep penetration welding with infrared laser for T2 seconds after blue light preheating.

[0022] According to a preferred embodiment, in step S30, the output trajectory of the infrared laser beam can be controlled by a program-controlled swing motor. The adjustment range of the swing motor includes the adjustment of the motor diameter swing, the adjustment of the motor frequency swing, and the adjustment of the motor trajectory swing.

[0023] According to a preferred embodiment, the number of red-blue composite lasers and the number of laser composite heads are both three. The three laser composite heads each include three processing areas, a, b, and c, which correspond to the top, middle, and bottom of the material to be processed, respectively.

[0024] Where 'a' is divided into a1 and a2;

[0025] b is divided into b1 and b2;

[0026] c is divided into c1 and c2;

[0027] Step S400: The processing sequence is b1, a1, a2, c1, c2;

[0028] Step S410: The processing sequence is b1, b2, a1, a2, c1, c2;

[0029] Step S420: The processing sequence is b1, b2, a1, a2, b2, c1, c2.

[0030] According to a preferred embodiment, step S400 can be divided into step S401 and step S402.

[0031] Step S401: b1;

[0032] Step S402: a1, a2, c1, c2;

[0033] Step S410 can be divided into steps S411 and S412.

[0034] Step S411: b1, b2;

[0035] Step S412: a1, a2, c1, c2;

[0036] Step S420 can be divided into steps S421 and S422.

[0037] Step S421: b1, b2;

[0038] Step S422: a1, a2, b2, c1, c2.

[0039] The technical solution of this utility model embodiment has at least the following advantages and beneficial effects:

[0040] This invention features a red-blue composite laser emitter and a laser combining head. The emitter outputs a blue laser beam and an infrared laser beam, respectively. The laser combining head ensures that the axes of the two laser beams coincide in space, enabling precise and efficient welding of multiple busbars to the BC battery using the red-blue composite laser. The infrared laser beam performs deep penetration welding, while the blue laser beam provides preheating and slow cooling, and moderately conducts heat during welding. This results in high uniformity, excellent welding effect, avoidance of weld buildup and pores, high yield, high efficiency, and strong stability. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 A schematic diagram of a laser welding device for BC battery busbars provided for an embodiment of this utility model;

[0043] Figure 2 A schematic diagram of the optical path structure of the laser composite head provided in this embodiment of the utility model;

[0044] Figure 3 A three-dimensional structural schematic diagram of the laser composite head provided in an embodiment of this utility model;

[0045] Figure 4 A top view of the BC battery and busbar distribution provided for an embodiment of this utility model;

[0046] Figure 5 A schematic diagram of the welding process of the BC battery and the busbar provided in this embodiment of the utility model.

[0047] Icons: 1. Blue light lens; 2. First reflector; 3. Second reflector; 4. Infrared lens; 5. Third reflector; 6. Red-blue composite lens; 7. CCD camera; 8. CCD monitoring lens; 9. Fourth reflector; 10. Red-blue composite laser; 11. Composite fiber; 12. Laser composite head; 121. Laser nozzle; 13. Spring; 14. Oscillating motor; 15. Machining platform; 16. X-axis moving assembly; 17. Y-axis moving assembly. Detailed Implementation

[0048] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings.

[0049] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0051] Example

[0052] Please refer to Figures 1 to 5 A laser welding device for BC battery busbars includes: a laser composite head 12, comprising a blue laser component, an infrared laser component, and a CCD component; the CCD component and the infrared laser component are located on the left and right sides of the blue laser component, respectively; the blue laser component includes a blue lens 1, a first reflector 2, a second reflector 3, and a red-blue composite lens 6 arranged sequentially along the output direction of the blue laser beam; the infrared laser component includes an infrared lens 4 and a third reflector 5 arranged sequentially along the output direction of the infrared laser beam; the CCD component includes a CCD camera 7 and a CCD sensor 8 arranged sequentially. The system includes a monitoring lens 8 and a fourth reflecting mirror 9; a third reflecting mirror 5 located to the right of the second reflecting mirror 3 and a fourth reflecting mirror 9 located to the left of the first reflecting mirror 2; a red-blue composite laser emission source connected to the laser composite head 12 via a composite optical fiber 11; and a processing platform 15, comprising an X-axis moving component 16 for moving the laser composite head 12 in the X-axis direction, a Y-axis moving component 17 for moving the laser composite head 12 in the Y-axis direction, and a processing table, wherein the X-axis moving component 16 and the Y-axis moving component 17 are mounted on the processing table.

[0053] Preferably, the red-blue composite laser emission source includes a plurality of red-blue composite lasers 10, each red-blue composite laser 10 corresponds to a laser composite head 12, and each red-blue composite laser 10 is connected to the corresponding laser composite head 12 through a composite optical fiber 11.

[0054] Preferably, the blue laser beam wavelength is between 400nm and 500nm, and the infrared laser beam wavelength is between 800nm ​​and 1100nm.

[0055] Preferably, a laser nozzle 121 is detachably connected to the lower end of the laser composite head 12, and a spring 13 is connected between the lower end of the laser composite head 12 and the laser nozzle 121. The spring 13 prevents the laser nozzle 121 from separating from the laser composite head 12, and effectively cushions the laser nozzle 121 from collisions to avoid damage.

[0056] Preferably, the device also includes a swing motor 14, which is connected to the third reflector 5. The power output end of the swing electrode can be connected to the third reflector 5 via a swing element, thereby adjusting the angle position of the third reflector 5 by controlling the swing motor 14.

[0057] Preferably, both the blue laser beam and the infrared laser beam are coaxially output after passing through the red-blue composite lens 6.

[0058] A welding method for a BC battery busbar laser welding device includes the following steps:

[0059] Step S10: Place the glass backplate onto the processing platform 15.

[0060] Step S20: Place the battery cell string and EVA material on the glass backing, and attach the copper foil to the EVA material;

[0061] Step S30: Adjust the position of the laser composite head 12 by using the X-axis moving component 16 and the Y-axis moving component 17, and adjust the output trajectory of the infrared laser beam by controlling the swing motor 14 through the program, so as to control the coaxial output of the infrared laser beam and the blue laser beam.

[0062] Step S40: Weld the busbar onto the copper foil. First, preheat with blue light for T1 seconds, and then perform deep penetration welding with infrared laser for T2 seconds after blue light preheating.

[0063] Preferably, in step S30, the output trajectory of the infrared laser beam can be controlled by the swing motor 14 through program control. The adjustment range of the swing motor 14 includes the adjustment of the motor diameter swing, the adjustment of the motor frequency swing, and the adjustment of the motor trajectory swing.

[0064] Preferably, there are three red-blue composite lasers 10 and three laser composite heads 12. The three laser composite heads 12 each include three processing areas a, b, and c, which correspond to the top, middle, and bottom of the material to be processed, respectively.

[0065] Where 'a' is divided into a1 and a2;

[0066] b is divided into b1 and b2;

[0067] c is divided into c1 and c2;

[0068] Step S400: The processing sequence is b1, a1, a2, c1, c2;

[0069] Step S410: The processing sequence is b1, b2, a1, a2, c1, c2;

[0070] Step S420: The processing sequence is b1, b2, a1, a2, b2, c1, c2.

[0071] Preferably, step S400 can be divided into step S401 and step S402;

[0072] Step S401: b1;

[0073] Step S402: a1, a2, c1, c2;

[0074] Step S410 can be divided into steps S411 and S412.

[0075] Step S411: b1, b2;

[0076] Step S412: a1, a2, c1, c2;

[0077] Step S420 can be divided into steps S421 and S422.

[0078] Step S421: b1, b2;

[0079] Step S422: a1, a2, b2, c1, c2.

[0080] The working principle of this utility model:

[0081] This invention features a red-blue composite laser emitter and a laser combining head 12. The red-blue composite laser emitter outputs a blue laser beam and an infrared laser beam, respectively. The laser combining head 12 allows the axes of the two laser beams to coincide in upper space, forming a red-blue composite laser. This composite laser can precisely and efficiently weld multiple busbars to BC batteries. The infrared laser beam performs deep penetration welding, while the blue laser beam provides preheating and slow cooling, and moderately conducts heat during welding. This results in high uniformity, excellent welding effect, avoidance of weld buildup and pores, high yield, high efficiency, and strong stability.

[0082] During the welding process, solder with a melting point lower than that of the heated welding substrate (BC battery or silicon substrate) is melted into the heated welding substrate (BC battery or silicon substrate). With the help of flux and relying on capillary action, the solder wets the surface of the welding substrate (BC battery or silicon substrate) and undergoes a chemical change to form an alloy layer, thereby making the welding substrate (BC battery or silicon substrate) and the solder an integral whole. The welding temperature can be selected from 190-230℃.

[0083] This embodiment uses a red-blue composite laser 10, with an infrared laser power of 100-3000W and a blue laser power of 100-3000W. This red-blue composite welding head can adapt to different spot sizes, and collimation and focus can be adjusted. The back electrode structure of the BC battery is fragile and easily damaged by mechanical pressing. Laser welding achieves stress-free connection, avoiding microcracks. The blue laser and infrared laser work together to improve the welding quality of the product to be processed (BC battery). The blue laser beam preheats the BC battery, and the infrared laser beam performs deep penetration welding. The blue laser beam (selecting a high absorptivity band of 455nm) rapidly heats the surface of the busbar, removing the oxide layer and reducing the surface tension of the molten metal; the infrared laser beam utilizes the high absorptivity of the metal to achieve deep penetration welding, ensuring metallurgical bonding between the copper strip and the plating. The blue laser beam can locally preheat the BC battery, reducing the energy density required for the infrared laser, minimizing the heat-affected zone (HAZ), and avoiding damage to the silicon substrate or passivation layer. In addition, precise control of heat input can be achieved through timing control (blue laser uses blue laser beam for preheating, and infrared laser uses infrared laser beam for deep melting) or spatial beam shaping (coaxial / paraxial composite), resulting in controllable temperature gradient, optimized melt pool fluidity, and reduced porosity.

[0084] This embodiment eliminates the need for slotting welding, whereas traditional processes require laser ablation of the dielectric layer to expose the solder pads. This embodiment directly welds through the dielectric layer, reducing steps and the breakage rate. The red-blue composite laser 10 allows for flux-free welding; the blue laser beam's cleaning effect reduces reliance on flux, avoids residual corrosion, and improves long-term reliability. Online quality monitoring of the blue laser allows real-time monitoring of the molten pool state using the plasma emission signal induced by the blue laser, achieving closed-loop control and simultaneous dual-beam operation, eliminating the multi-step processes of positioning, slotting, and welding inherent in traditional methods. Preheating with the blue laser beam reduces the energy requirements of infrared laser beam processing. The blue laser beam can penetrate transparent dielectric layers; BC batteries often have a SiNx / SiO2 protective layer on the back. The blue laser beam can directly heat the underlying metal busbar (such as a copper plating) without pre-slotting. It is compatible with various plating types, exhibiting high absorption rates for copper, silver, tin, and other busbar platings, reducing sensitivity to plating uniformity. Blue light spots are relatively large (usually 0.2-3.5mm).

[0085] In this embodiment, three red-blue composite lasers 10 can be selected for rapid processing of busbars. Each red-blue composite laser 10 includes a blue laser and an infrared laser. The blue laser's wavelength can be selected between 435-473nm, and its power range can be 10-4000W. The infrared laser's wavelength can be selected between 1030-1080nm, and its power range can be 100-200KW. The spot size can range from 0.3-3mm. The laser processing area is less than 280*280mm, covering all commercially available battery cell sizes, including half-cell and full-cell sizes, ensuring the accuracy of battery processing efficiency improvements. In this embodiment, based on the coaxial composite of the infrared and blue laser beams, a program-controlled oscillation motor 14 causes the infrared laser to generate a certain oscillation diameter, oscillation frequency, and oscillation trajectory. Figure 4 as well as Figure 5 As shown, the arrows indicate the movement direction of the BC battery and busbar. The BC battery and busbar can be moved via the processing platform 15. Conversely, the three laser composite heads 12 can be moved and adjusted along the X-axis and Y-axis directions by controlling the X-axis moving component 16 and Y-axis moving component 17. The BC battery and busbar can be stationary on the processing platform 15, thereby achieving position adjustment of the three processing areas a, b, and c. For example, when it is necessary to switch the position of the processing area a1 to a2, only the Y-axis moving component 17 needs to be adjusted. The CCD component can adjust the detection direction position via the fourth reflector 9, thereby accurately positioning the workpiece. It is coaxially set with the infrared laser beam and the blue laser beam, greatly improving the positioning accuracy. The durations T1 and T2 are adjusted according to the product being processed. Specifically, both T1 and T2 can be selected as 500ms or 600ms, etc. The T1 and T2 time values ​​can be the same or different. Figure 5 In the diagram, the dashed lines represent the locations of the three processing areas, a, b, and c.

[0086] The technical means disclosed in this utility model are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

Claims

1. A laser welding device for BC battery busbars, characterized in that, include: A laser composite head includes a blue laser component, an infrared laser component, and a CCD component; the CCD component and the infrared laser component are located on the left and right sides of the blue laser component, respectively; the blue laser component includes a blue lens, a first reflector, a second reflector, and a red-blue composite lens arranged sequentially along the output direction of the blue laser beam; the infrared laser component includes an infrared lens and a third reflector arranged sequentially along the output direction of the infrared laser beam; the CCD component includes a CCD camera, a CCD monitoring lens, and a fourth reflector arranged sequentially; the third reflector is located to the right of the second reflector, and the fourth reflector is located to the left of the first reflector; A red-blue composite laser emission source is connected to the laser composite head via a composite optical fiber; The processing platform includes an X-axis moving component for moving the laser composite head in the X-axis direction, a Y-axis moving component for moving the laser composite head in the Y-axis direction, and a processing table, wherein the X-axis moving component and the Y-axis moving component are disposed on the processing table.

2. The BC battery busbar laser welding device according to claim 1, characterized in that, The red-blue composite laser emission source includes a plurality of red-blue composite lasers, each of which corresponds to a laser composite head, and each of the red-blue composite lasers is connected to a laser composite head through a composite optical fiber.

3. The BC battery busbar laser welding device according to claim 1, characterized in that, Blue laser beams have a wavelength range of 400nm-500nm, while infrared laser beams have a wavelength range of 800nm-1100nm.

4. The BC battery busbar laser welding device according to claim 1, characterized in that, The lower end of the laser composite head is detachably connected to a laser nozzle, and a spring connects the lower end of the laser composite head to the laser nozzle.

5. The BC battery busbar laser welding device according to claim 1, characterized in that, It also includes a swing motor, which is connected to the third reflector.

6. The BC battery busbar laser welding device according to claim 5, characterized in that, Both the blue laser beam and the infrared laser beam are output coaxially after passing through the red-blue composite lens.

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