Thin film laser processing apparatus and method

Abstract

This invention provides a thin-film laser processing apparatus, including a laser, a galvanometer, a lens, and a worktable. The laser beam emitted by the laser passes sequentially through the galvanometer and the lens to the worktable. It also includes an air-blowing assembly for bonding the thin film to the workpiece surface. The air-blowing assembly is positioned close to the worktable, with its air outlet facing the worktable. A thin-film laser processing method is also provided. In this invention, the addition of the air-blowing assembly generates a pressurized airflow that acts on the outer side of the thin film, reducing the distance between the thin film and the workpiece surface. This ensures the thin film adheres to the workpiece surface, guaranteeing the quality of the product after welding, and eliminating the need for natural cooling time, allowing for rapid transition to the next processing station.

Description

Technical Field

[0001] This invention relates to laser processing, and more particularly to a thin-film laser processing apparatus and method. Background Technology

[0002] PET film (Polyester film) is a packaging film with comprehensive performance. It has excellent physical and chemical properties, dimensional stability, transparency, and recyclability, and can be widely used in magnetic recording, photosensitive materials, electronics, electrical insulation, industrial films, packaging decoration and other fields.

[0003] However, most thermoplastic packaging currently used employs heating strips for manual or mechanical sealing, which is inefficient, inflexible in operation, and requires high temperature control due to the equipment operating at high temperatures for extended periods. The heating element is also prone to damage, increasing equipment costs.

[0004] Chinese patent CN105665942A discloses a laser device and method for thin film processing. The laser device cuts and fuses the thin film covering the top and bottom of a packaging box before it flows into the next process and undergoes heat shrinking treatment, achieving a superior packaging effect compared to traditional methods. However, this patent does not address situations where heat shrinking is unsuitable for certain products. Laser film fusion only around the product's perimeter results in a large amount of gas inside the film. For example, in the packaging of narrow-edged battery cells resembling a sheet of paper, the film may not seal tightly, and the large amount of gas inside can cause the product to shake, affecting the sealing effect. Furthermore, how to shorten the cooling time after laser fusion and before the next process to improve production efficiency remains to be addressed. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a thin film laser processing apparatus and method.

[0006] This invention is implemented as follows:

[0007] This invention provides a thin-film laser processing apparatus, including a laser, a galvanometer, a lens, and a worktable. The laser beam emitted by the laser passes sequentially through the galvanometer and the lens to the worktable. The apparatus also includes an air blowing assembly for attaching a thin film to the surface of a workpiece. The air blowing assembly is positioned close to the worktable and its air outlet faces the worktable.

[0008] Furthermore, the air pressure generated by the air blowing assembly is 0.1 to 0.5 MPa, and the airflow discharged by the air blowing assembly acts obliquely on the workpiece processing surface.

[0009] Furthermore, it also includes a dust extraction assembly, the air extraction port of which faces and is close to the workbench.

[0010] Furthermore, it also includes a pressing assembly, which includes a protective lens and a drive that compresses the protective lens film to the workpiece processing area.

[0011] Furthermore, the protective lens is made of zinc selenide material and has a thickness of 1–4 mm.

[0012] Furthermore, it also includes at least two beam splitting paths, with the laser emitting light that enters each beam splitting path to process the workpiece simultaneously.

[0013] This invention also provides a thin-film laser processing method, comprising the following steps:

[0014] Fix the workpiece to be processed, turn on the air blowing component to make the film adhere to the surface of the workpiece, and use the protective glass to ensure that the workpiece to be processed is adhered to the film;

[0015] Adjust the working distance between the surface of the workpiece to be processed and the lens;

[0016] Edit and import the processing layer of the workpiece to be processed into the laser, and adjust the process parameters accordingly;

[0017] Turn on the dust extraction device and begin processing until completion.

[0018] Furthermore, in modern machining processes where there are multiple machining positions between the workpiece and the thin film, the laser beam emitted by the laser is split and processed at multiple machining positions simultaneously.

[0019] Furthermore, the workpiece is a battery cell, which is encapsulated with a PET film, and the four edges of the battery cell's plastic protective shell are processed simultaneously through four beam-splitting optical paths.

[0020] The present invention has the following beneficial effects:

[0021] In this invention, when using laser to process thin films, the workpiece is specifically encapsulated through the thin film. An air blowing component is added, which generates a certain pressure airflow that acts on the outside of the thin film, reducing the distance between the thin film and the workpiece surface. The thin film adheres to the workpiece surface, ensuring the quality of the product after film welding. In addition, the air blowing component can quickly cool the welded product, saving the time required for natural cooling, and allowing it to quickly enter the next work area, making it very suitable for assembly line operations. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a first-view structural schematic diagram of the thin-film laser processing apparatus provided in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the thin-film laser processing apparatus provided in an embodiment of the present invention from a second perspective.

[0025] Figure 3 This is a schematic diagram of the structure of the battery cell packaged in the thin-film laser processing device provided in an embodiment of the present invention;

[0026] Figure 4 A schematic diagram of the structure of the thin-film laser processing apparatus provided in the embodiments of the present invention, which has four beam-splitting paths;

[0027] Figure 5 A flowchart of a thin-film laser processing method provided in an embodiment of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] See Figure 1-3This invention provides a thin-film laser processing apparatus. The thin film (not shown in the figure) can be a PET film. The PET film is encapsulated on the outside of the workpiece 1 by laser processing. Especially when the workpiece 1 is a battery cell 11, using PET film laser encapsulation of the battery cell 11 can significantly improve the encapsulation efficiency of the battery cell 11. Specifically, the processing apparatus 2 includes a laser 21, a galvanometer 22, a lens 23, and a worktable. The laser beam emitted by the laser 21 passes through the galvanometer 22 and the lens 23 sequentially to the worktable. The worktable is the processing position, and a fixture is used to position the workpiece 1 to be processed. When the processing apparatus 2 is an independent device, the worktable is an independent processing table. When the processing apparatus 2 is part of an automated production line, the worktable is connected to the conveyor line of the automated production line and can be part of the conveyor line. The worktable is not a separate table structure, but the working area corresponding to the laser 21. Of course, it can also be an independent worktable. The workpiece 1 is transferred between the worktable and the conveyor line through a transfer device. When laser processing workpiece 1 is performed, the fixture positions workpiece 1 on the worktable, and the laser 21 starts working. After passing through a beam expander 24 with a certain magnification, the laser beam reaches the galvanometer 22. After being rotated 90° by the galvanometer 22, the laser beam forms a focal plane on the worktable through the lens 23. The galvanometer 22 can be a 3D scanning galvanometer 22, which can effectively ensure the processing area of ​​the laser 21. Furthermore, when the processing area on the surface of workpiece 1 is small, there is no need to adjust the position of workpiece 1 horizontally. Of course, the processing device 2 should include a control unit 28. The laser 22 generates a laser beam after receiving a signal from the control unit 28.

[0030] See Figure 2 as well as Figure 3 In the optimized scheme, the processing device 2 includes an air blowing assembly 25, which is positioned close to the worktable with its air outlet facing the worktable, specifically towards the surface of the workpiece 1 on the worktable, for attaching the film to the surface of the workpiece 1. In this embodiment, when using film to encapsulate the workpiece 1, especially when using PET film to insulate the battery cell 11, before the laser 21 operates, the air blowing assembly 25 blows air onto the outside of the film. The air pressure reduces the distance between the PET film and the surface of the battery cell 11, allowing the film to adhere to the surface of the battery cell 11, and the air between them is expelled, ensuring the encapsulation quality of the battery cell 11. On the other hand, since the film is laser-welded, the overall temperature is relatively high after processing. The airflow generated by the air blowing assembly 25 can quickly cool the welded product, saving natural cooling time. The processed product can be directly transferred to the next station, making it very suitable for automated production lines.

[0031] In a preferred embodiment, the air pressure generated by the air blowing assembly 25 is 0.1–0.5 MPa, and the exhaust airflow acts obliquely on the processed surface of the workpiece 1. In this embodiment, the air pressure generated by the air blowing assembly 25 is limited. This pressure serves two purposes: firstly, it forces the film to adhere to the outer surface of the product, achieving the purpose of venting; secondly, it prevents the airflow generated by the air blowing assembly 25 from causing turbulence in the airflow around the workpiece 1, thus mitigating the impact on dust generated during processing. Furthermore, the air blowing assembly 25 acts obliquely on the processed surface of the workpiece 1, specifically at a 45-degree angle, thereby allowing the airflow generated by the air blowing assembly 25 to have a larger effective area on both the film and the workpiece 1, and to compress the air between the film and the workpiece 1 in a certain direction.

[0032] See Figure 2 Furthermore, the processing device 2 also includes a dust extraction component 26, with its air extraction port facing and close to the worktable. In this embodiment, the dust extraction component 26 can extract the fumes generated during processing. The dust extraction component 26 is staggered from the air blowing component 25, resulting in a lower airflow pressure from the dust extraction component 26, which does not affect the air pressure generated by the air blowing component 25. Specifically, the dust extraction component 26 is mainly located near the processing area between the film and the workpiece 1, typically at the edge of the film, where the fumes generated during laser processing are quickly extracted. The air blowing component 25, on the other hand, primarily acts on the main bonding area between the film and the workpiece 1, biased towards the center of the film.

[0033] See Figure 2 In another embodiment of the present invention, the processing device 2 further includes a pressing assembly (not shown in the figure). The pressing assembly includes a protective lens and a driving component, wherein the driving component is used to control the pressing of the protective lens onto the outside of the film. The pressing part of the protective lens is biased towards the edge of the film. In actual processing, the air blowing assembly 25 is first used to attach the film to the outer surface of the workpiece 1, and then the driving component is used to control the pressing position of the protective lens onto the edge of the film. The laser beam generated by the laser 21 passes through the protective lens to weld the edge of the film. Especially when the PET film encapsulates the battery cell 11, the end of the battery cell 11 is a plastic protective shell 12. When the PET film is attached to the outer surface of the battery cell 11, the edge of the PET film is attached to the plastic protective shell 12. Since the size of the plastic protective shell 12 is relatively small, the welding width of the PET film at this location is too narrow. By pressing with the protective lens, the welding quality can be guaranteed. See details. Figure 3 The dashed arrows indicate the welding points of the PET film. For the protective lens, zinc selenide is used as the material; it is a chemically inert material with a controlled thickness of 1–4 mm and a wavelength of 0.5–26 μm. A 10.3 μm CO2 laser is used to process the PET film. This wavelength laser beam has good transmission performance for the protective lens and features low optical transmission loss, high purity, strong environmental adaptability, easy processing, and good uniformity and consistency of refractive index.

[0034] See Figures 2-4 Furthermore, the processing device 2 also includes at least two beam splitting paths 27. The laser beam emitted by the laser 21 is split and enters each beam splitting path 27, and the workpiece 1 is processed simultaneously through the beam splitting paths 27. In this embodiment, each beam splitting path 27 corresponds to a processing position on the workpiece 1. The number of beam splitting paths 27 can be determined according to the actual processing positions. For example, when there are many processing positions on the workpiece 1, the number of beam splitting paths 27 does not need to correspond to the number of processing positions. Multiple beam splitting paths 27 can simultaneously process each processing position of each processing part of the workpiece 1. When there are few processing positions, the beam splitting paths 27 correspond one-to-one with the processing positions. Of course, the number of lasers 21 is also adjusted according to the different number of beam splitting paths 27. Each laser 21 can split a maximum of two beam splitting paths 27. For example, when there are two beam splitting paths 27, only one laser 21 can be used, while when there are four beam splitting paths 27, two lasers 21 are used. Specifically, when the battery cell 11 is encapsulated with PET film, the battery cell 11 is typically a flat, square structure. Two PET films are used to cover the battery cell 11, and are respectively attached to the front and rear surfaces of the battery cell 11. The two short sides of each PET film are fused to the two plastic protective shells 12 (located at the two ends of the battery cell 11) for encapsulation. The long sides of the two PET films are fused to each other at two opposite sides of the battery cell 11; that is, the short sides of the PET film are fused to the plastic protective shell 12, and the long sides of the PET film are fused to the long sides of another PET film for encapsulation. Furthermore, since the battery cell 11 is... In a square shape, each plastic protective shell 12 has four sides, allowing for the setting of four beam-splitting optical paths 27, each corresponding to one of the four sides of the plastic protective shell 12. In this case, there are two lasers 21. Each plastic protective shell 12 uses four sets of pressing components to simultaneously press one side of the short side of two PET films. The four beam-splitting optical paths 27 can simultaneously weld and seal the plastic protective shell 12. Then, the two opposing beam-splitting optical paths 27 seal the long sides of the two PET films respectively. Finally, the four beam-splitting optical paths 27 simultaneously seal the four sides of the other side of the plastic protective shell 12. The sealing process is very efficient.

[0035] See Figures 2-5 This invention also provides a thin-film laser processing method using the aforementioned processing apparatus 2, specifically including the following steps:

[0036] Fix the workpiece 1 to be processed, specifically fix the workpiece 1 to be processed at the worktable, attach the film to the corresponding surface of the workpiece 1, turn on the air blowing component 25, and the airflow from the air blowing component 25 will attach the film to the surface of the workpiece 1. Use protective glass to press the edge of the film to the surface of the workpiece 1 from the outside.

[0037] Adjust the working distance between the surface of the workpiece 1 to be processed and the lens 23, specifically the distance between the lens 23 and the workpiece 1 and the film encapsulation area, so that the focal point of the lens 23 is located on the film. Specifically, a mating model of the workpiece 1 and the film can be pre-added in the laser 21, and the focal point of the laser 21 can be simulated in the software to be located at the corresponding position of the mating model, thereby adjusting the actual laser focal point to be located at the corresponding position of the film, and the two move synchronously.

[0038] Edit and import the processing layer of the workpiece 1 to be processed into the laser 21, and adjust the process parameters. For the processing layer, project the processing layer onto the mating model. The laser 21 works along the projection on the mating model. In addition, adjust the parameters of the laser 21, such as wavelength, power, frequency and area.

[0039] Turn on the dust extraction device, and at the same time, the laser 21 will work. The laser beam will process the edge of the film through the protective glass. The dust extraction device will remove the smoke and dust generated during the laser welding process until the processing is completed.

[0040] In this embodiment, the air blowing assembly 25 and the protective glass work together to achieve a better fit between the film and the workpiece 1, which can expel the air between the film and the workpiece 1, ensuring the quality of the plastic sealing. The film has a good welded surface, and the melting point is complete without stringing, separation or over-melting. This improves the plastic sealing process for products that are not suitable for heat shrinking, shortens the cooling time after the film laser fusion, and allows it to be directly transferred to the next process for further processing, thus improving production efficiency.

[0041] In a preferred embodiment, when the workpiece 1 is a battery cell 11, a PET film is used to encapsulate the battery cell 11. There are multiple processing positions between the two. At the four edges of the plastic protective shell 12 of the battery cell 11, the short side of the PET film is laser-sealed with the plastic protective shell 12. In the part between two plastic protective shells 12, the long side of the two PET films is laser-sealed. The laser beam emitted by the laser 21 enters the four beam splitting optical paths 27 through the beam splitter. The four beam splitting optical paths 27 can process the four edges of the plastic protective shell 12 at the same time. That is, the plastic protective shell 12 can be processed in one go, which greatly improves efficiency.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A thin film laser processing device for insulating and packaging a battery cell, comprising a laser, a galvanometer, a lens and a worktable, a laser beam emitted by the laser passes through the galvanometer and the lens to the worktable in sequence, characterized in that: It also includes an air blowing assembly for bonding the film to the workpiece surface. The air blowing assembly is located close to the worktable and its air outlet faces the worktable. The air pressure generated by the air blowing assembly is 0.1~0.5MPa, and the airflow discharged by the air blowing assembly acts obliquely on the workpiece processing surface. During operation, the air blowing assembly is first used on the bonding area between the film and the workpiece, biased towards the middle of the film, and then a laser is used to perform laser processing on the edge of the film. ​ The processing device also includes a dust extraction component, the air extraction port of which faces and is close to the worktable, and during operation, the dust extraction component is close to the processing area between the film and the workpiece, and the processing area is located at the edge of the film.

2. The thin-film laser processing apparatus as described in claim 1, characterized in that: It also includes a pressing assembly, which includes a protective lens and a drive that causes the protective lens to press a film onto the workpiece.

3. The thin-film laser processing apparatus as described in claim 2, characterized in that: The protective lens is made of zinc selenide material and has a thickness of 1-4 mm.

4. The thin-film laser processing apparatus as described in claim 1, characterized in that: It also includes at least two beam splitting paths, with the laser emitting light that enters each beam splitting path to process the workpiece simultaneously.

5. A thin-film laser processing method, characterized in that, Includes the following steps: Fix the workpiece to be processed, turn on the air blowing assembly. The air pressure generated by the air blowing assembly is 0.1~0.5MPa, and the airflow discharged by the air blowing assembly acts obliquely on the processing surface of the workpiece. The air blowing assembly acts on the bonding area between the film and the workpiece, biased towards the middle position of the film, so that the film and the workpiece surface are bonded. Protective glass is used to ensure that the workpiece to be processed position is bonded to the film. Adjust the working distance between the surface of the workpiece to be processed and the lens; Edit and import the processing layer of the workpiece to be processed into the laser, and adjust the process parameters accordingly; Turn on the dust extraction device and use a laser to perform laser processing on the edges of the film until completion.

6. The thin-film laser processing method as described in claim 5, characterized in that: When there are multiple processing positions between the workpiece and the film, the laser beam emitted by the laser is split and processed at multiple processing positions simultaneously.

7. The thin-film laser processing method as described in claim 6, characterized in that: The workpiece is a battery cell, which is encapsulated in PET film. The four edges of the plastic protective shell of the battery cell are processed simultaneously through four beam-splitting optical paths.

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