Laser etching method and device capable of changing etching line width

Abstract

The invention discloses a laser etching method and device capable of changing the etching line width, and the etching method comprises the steps: providing a first diffraction element, and carrying out the diffraction of a laser beam through the first diffraction element, so as to obtain a rectangular light spot; providing a first rotating device, and rotating the first diffraction element through the first rotating device so as to adjust the projection width of the rectangular light spot in the preset etching direction; and focusing the rectangular light spot on the photovoltaic cell through a focusing device, and etching the photovoltaic cell based on the rectangular light spot. According to the etching method, the etching line width can be accurately adjusted in real time, the etching flexibility and adaptability are enhanced, the operation is simple, and the cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic cell preparation, and in particular to a laser etching method and device capable of changing etching line width. Background Art

[0002] In the manufacturing process of photovoltaic cells, laser etching technology is used to remove the middle light-absorbing layer. After etching, the light-absorbing layer will form etched grooves. The two sides of the etched grooves are cleaned to expose the cross-section of the light-absorbing layer for the injection of the metal back electrode, thereby achieving the conduction of the metal positive and negative electrodes. However, due to the inherent characteristics of the light-absorbing layer material, metal lead ions will diffuse with the back electrode material and other adverse reactions. Over time, the performance of the photovoltaic cell's light-absorbing layer will gradually become unstable, and the battery life will be rapidly shortened.

[0003] To solve this problem, it is necessary to take protective measures for the edges of the etched grooves. However, the laser used for etching is usually extremely fine and requires extremely high equipment precision, especially when the etched grooves that have been etched need to be etched a second time, the processing difficulty increases significantly. At the same time, in order to meet the conductivity requirements between the positive and negative electrodes, the line width of the secondary etching must meet certain standards. This requires adjusting the line widths of both the laser beam during the first etching and the laser beam during the second etching to meet the conductivity requirements of the secondary etching and the positive and negative electrodes. In addition, in order to achieve different etching widths, it is often necessary to set up multiple laser beams for etching in advance, and the consistency of the laser is difficult to guarantee. Summary of the invention

[0004] The object of the present invention is to provide a laser etching method and device capable of adjusting the etching line width of a laser beam used for etching to flexibly adapt to etching requirements while ensuring laser consistency and capable of changing the etching line width.

[0005] To achieve the above object, the present invention discloses a laser etching method capable of changing the etching line width, comprising: Providing a first diffraction element, diffracting the laser beam through the first diffraction element to obtain a rectangular light spot; Providing a first rotating device, and rotating the first diffraction element by the first rotating device to adjust the projection width of the rectangular light spot in a preset etching direction; The rectangular light spot is focused on the photovoltaic cell by a focusing device, and the photovoltaic cell is etched based on the rectangular light spot.

[0006] Specifically, a second diffraction element is also provided. Before the rectangular light spot is focused on the photovoltaic cell by the focusing device, the rectangular light spot is split by the second diffraction element to form a plurality of rectangular sub-spots, and the rectangular sub-spots are focused on the photovoltaic cell by the focusing device, so as to etch the photovoltaic cell based on the rectangular sub-spots.

[0007] Furthermore, the etching method also adjusts the spacing between the rectangular sub-spots through a second rotating device.

[0008] Specifically, before the laser beam is diffracted by the first diffraction element, the etching method also shapes the laser beam by a beam adjuster, and the beam adjuster includes at least one of a beam converter, a shape shaping device, a divergence angle control device or a spatial light modulator.

[0009] Specifically, the first rotating device and the second rotating device are hollow rotating motors.

[0010] The present invention also discloses a laser etching device capable of changing the etching line width, comprising: a light source for emitting a laser beam; a first diffraction element, used for diffracting the laser beam emitted by the light source to obtain a rectangular light spot; A first rotating device, used for rotating the first diffraction element to adjust the projection width of the rectangular light spot in a preset etching direction, thereby controlling the etching line width during laser etching; a second diffraction element, used for splitting the rectangular light spot adjusted by the first rotating device to form a plurality of rectangular sub-light spots; A focusing device is used to focus the rectangular sub-light spot on the photovoltaic cell.

[0011] Specifically, the laser etching device further includes a second rotating device for adjusting the spacing between each of the rectangular sub-spots, and the second rotating device is arranged between the second diffraction element and the focusing device.

[0012] Furthermore, the first rotating device and the second rotating device are hollow rotating motors.

[0013] Specifically, a beam adjuster is also arranged between the light source and the first diffraction element, and the beam adjuster is used to shape the laser beam. The beam adjuster includes at least one of a beam converter, a shape shaping device, a divergence angle control device or a spatial light modulator.

[0014] Specifically, the laser beam includes at least one of infrared light, green light, ultraviolet light or blue light.

[0015] Compared with the prior art, the etching method provided by the above technical solution of the present invention rotates the first diffraction element in real time through the first rotating device, thereby rotating the rectangular light spot formed by the first diffraction element. Since the rectangular light spot has a long side and a short side, the projection of the rectangular light spot in the etching direction will change its width with the rotation during the rotation, thereby realizing the real-time adjustment of the etching line width. The line width adjusted in real time can adapt to the requirements of different working scenes, and the etching needs of different line widths can be achieved by relying on only a single laser beam, the consistency of the laser is guaranteed, the flexibility and adaptability of etching are enhanced, the operation is simple, and it is energy-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a flow chart of a laser etching method capable of changing the etching line width in an embodiment of the present invention.

[0017] Figure 2 The figure is a flow chart of a laser etching method capable of changing the etching line width in another embodiment of the present invention.

[0018] Figure 3 Schematic diagram of a laser etching method for changing the etching line width when the first diffraction element is rotated 0° in an embodiment of the present invention.

[0019] Figure 4 Schematic diagram of a laser etching method in which the etching line width can be changed when the first diffraction element is rotated 90° in an embodiment of the present invention.

[0020] Figure 5 Schematic diagram of the structure of a laser etching device capable of changing the etching line width in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0022] The embodiment of the present invention discloses an etching method to adjust the etching line width of a laser beam, thereby flexibly adapting to the etching requirements of different application scenarios while improving the etching efficiency and increasing the yield of photovoltaic cells. Figure 1 and Figure 5 As shown, the etching method specifically includes the following steps: S1: Provide a first diffraction element 1, and diffract the laser beam to obtain a rectangular light spot through the first diffraction element 1. In this embodiment, the first diffraction element 1 shapes or filters the laser beam to form a rectangular light spot with a flat-top characteristic.

[0023] S2: Provide a first rotating device 2, and rotate the first diffractive element 1 by the first rotating device 2 to adjust the projection width of the rectangular light spot in the preset etching direction. In this embodiment, the rectangular light spot is used for etching, and adjusting the projection width of the rectangular light spot in the etching direction controls the etching line width during laser etching.

[0024] S3: focusing the rectangular light spot on the photovoltaic cell through the focusing device 3, and etching the photovoltaic cell based on the rectangular light spot. In this embodiment, the focusing device 3 can be a telecentric lens, a non-telecentric lens or an ordinary focusing lens. The main purpose of the focusing device 3 is to image the rectangular light spot so that the morphology of the rectangular light spot is imaged on the photovoltaic cell, thereby achieving the effect of removing the material structure of the photovoltaic cell with a high-power imaging light spot.

[0025] Compared with the prior art, the etching method proposed in the present invention realizes precise rotation operation of the first diffraction element 1 by introducing the first rotating device 2 on the basis of the first diffraction element 1 processing the laser beam into a rectangular light spot. Since the rectangular light spot has clear long and short sides, when the first diffraction element 1 rotates with the driving of the rotating device, the projection width of the rectangular light spot in the preset etching direction will change accordingly. This change is real-time and controllable, thereby realizing precise adjustment of the etching line width. This measure enhances the flexibility and adaptability of etching, so that the etching method proposed in the present invention can meet the diversified line width requirements under different process requirements.

[0026] At the same time, in different working scenarios, whether it is fine narrow line width etching or wider line width processing, this etching method can meet the needs with the precise control of a single laser beam. This simplifies the operation process, reduces energy consumption and dependence on complex equipment and multiple processes, while improving the efficiency and accuracy of the etching operation, and ensuring the consistency of the etching laser.

[0027] In summary, the etching method of the present invention realizes real-time and precise adjustment of etching line width, guarantees the consistency of etching laser quality, and reduces etching costs through the design of rotation, diffraction, and simultaneous etching of multiple beams.

[0028] Specifically, see Figure 2 As shown, in another preferred embodiment of the present invention, the etching method further comprises: S1: Provide a first diffraction element 1, and diffract the laser beam through the first diffraction element 1 to obtain a rectangular light spot.

[0029] S2: providing a first rotating device 2, and rotating the first diffraction element 1 by the first rotating device 2 to adjust the projection width of the rectangular light spot in the preset etching direction.

[0030] S3: Provide a second diffraction element 4, and split the rectangular light spot to form a plurality of rectangular sub-spots through the second diffraction element 4. In this embodiment, the second diffraction element 4 splits the rectangular light spot into a plurality of parallel rectangular sub-spots, and the splitting does not change the rotation angle of the rectangular light spot, but only splits the rectangular light spot into a plurality of rectangular sub-spots with the same rotation angle and shape, and the number of the rectangular sub-spots obtained by the splitting is 2~n, where n is a positive integer greater than or equal to 2.

[0031] S4: adjusting the intervals between the rectangular sub-spots by the second rotating device 5 .

[0032] S5: Focus the rectangular sub-spot on the photovoltaic cell through the focusing device 3, and etch the photovoltaic cell based on the rectangular sub-spot. The preferred width of the rectangular sub-spot finally focused on the photovoltaic cell is in the range of 0.01 mm to 1 mm, with a preferred value of 10 um, and the preferred length is in the range of 0.01 mm to 1 mm.

[0033] It should be noted that the essence of the rectangular light spot and the rectangular sub-spot is still a laser beam, and the naming here is only used to distinguish the laser beam processed by the first diffraction element 1 or the second diffraction element 4. In this embodiment, the second diffraction element 4 is used to further process the rectangular light spot formed by the first diffraction element 1 and split it into a number of small rectangular sub-spots. Under the action of the focusing device 3, these rectangular sub-spots can be focused on the photovoltaic cell at the same time, so as to realize the simultaneous etching of multiple laser beams, thereby significantly improving the etching efficiency, doubling the etching area per unit time, and ensuring the stability and consistency of the etching quality.

[0034] Specifically, in this embodiment, before the laser beam is diffracted by the first diffraction element 1, the laser beam is shaped by a beam adjuster 6 to meet the etching requirements. The beam adjuster 6 includes at least one of a beam converter, a shape shaping device, a divergence angle control device or a spatial light modulator.

[0035] Furthermore, the first rotating device 2 and the second rotating device 5 are hollow rotating motors. Figure 5 As shown, the first rotating device 2 is arranged on the first diffraction device, and the second rotating device 5 is arranged on the second diffraction device. The hollow rotating motor can realize 360° rotation, and the first rotating device 2 can realize close regulation of the projection of the rectangular light spot, that is, realize fine regulation of the projection of the light spot width, and the second rotating device 5 can adjust the spacing of the rectangular sub-light spots, thereby realizing unified regulation.

[0036] Specifically, in this embodiment, the laser beam is emitted by a preset light source 7, and the laser beam emitted by the light source 7 includes at least one of infrared light, green light, ultraviolet light or blue light.

[0037] by Figure 3 and Figure 4 Taking the two embodiments shown as examples, the adjustment principle of the etching method is explained: Figure 3 is a schematic diagram when the first diffraction element 1 is rotated 0°, Figure 4 This is a schematic diagram of the first rotating device 2 driving the first diffraction element 1 to rotate 90°. Figure 3 In the embodiment, the first diffraction element 1 does not rotate, and the rectangular sub-spot b formed by the rectangular spot a through the second diffraction element 4 and the focusing device 3 is projected in the etching direction as the short side of the rectangular sub-spot b. At this time, the line width is narrow, and Figure 4 In the embodiment, the first diffraction element 1 is rotated 90°, and the projection of the rectangular sub-spot b in the etching direction is the long side of the rectangular sub-spot b. Figure 3 In this embodiment, except when the long side of the rectangular sub-spot b is parallel to the etching direction and the projection is the short side of the rectangular sub-spot b, the projection of the rectangular sub-spot b in the etching direction is the product of the long side of the rectangular sub-spot b and the sine value of the angle between the long side and the etching direction, that is, L*sinα, where L is the length of the long side and α is the angle between the long side and the etching direction.

[0038] In another preferred embodiment of the present invention, a laser etching device capable of changing the etching line width is also disclosed. Figure 5 As shown, the laser etching device comprises: The light source 7 is used to emit a laser beam.

[0039] The first diffraction element 1 is used to diffract the laser beam emitted by the light source 7 to obtain a rectangular light spot.

[0040] The first rotating device 2 is used to rotate the first diffraction element 1 to adjust the projection width of the rectangular light spot in a preset etching direction, thereby controlling the etching line width during laser etching. The first rotating device 2 is arranged on the first diffraction element 1.

[0041] The focusing device 3 is used to focus the rectangular light spot on the photovoltaic cell to etch the photovoltaic cell.

[0042] Specifically, the laser etching device of this embodiment also includes a second diffraction element 4 arranged between the first diffraction element 1 and the focusing device 3, and the second diffraction element 4 is used to split the rectangular light spot adjusted by the first rotating device 2 to form a plurality of rectangular sub-spots; at this time, the focusing device 3 is used to focus the rectangular sub-spots on the photovoltaic cell to etch the photovoltaic cell.

[0043] Specifically, the laser etching device of this embodiment further includes a second rotating device 5 for adjusting the interval between each rectangular sub-spot, and the second rotating device 5 is disposed on the second diffraction element 4 .

[0044] Furthermore, the first rotating device 2 and the second rotating device 5 are hollow rotating motors.

[0045] Specifically, a beam adjuster 6 is also arranged between the light source 7 and the first diffraction element 1. The beam adjuster 6 is used to shape the laser beam. The beam adjuster 6 includes at least one of a beam converter, a shape shaping device, a divergence angle control device or a spatial light modulator.

[0046] Specifically, the laser beam that can be generated by the light source 7 includes at least one of infrared light, green light, ultraviolet light or blue light.

[0047] The specific contents of the light source 7, the first diffraction element 1, the first rotating device 2, the second diffraction element 4, the second rotating device 5, the focusing device 3 and the beam adjuster 6 are consistent with those of the etching method in the above embodiment and will not be repeated here.

[0048] The laser etching device of this embodiment significantly improves the etching efficiency and accuracy through real-time and flexible etching line width adjustment combined with simultaneous etching technology of multiple rectangular sub-spots, while maintaining ease of operation, wide applicability, and environmental protection and energy-saving characteristics.

[0049] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A laser etching method capable of changing the etching line width, characterized in that: include: Providing a first diffraction element, diffracting the laser beam through the first diffraction element to obtain a rectangular light spot; Providing a first rotating device, and rotating the first diffraction element by the first rotating device to adjust the projection width of the rectangular light spot in a preset etching direction; The rectangular light spot is focused on the photovoltaic cell by a focusing device, and the photovoltaic cell is etched based on the rectangular light spot.

2. The laser etching method capable of changing the etching line width according to claim 1, characterized in that: A second diffraction element is also provided. Before the rectangular light spot is focused on the photovoltaic cell by the focusing device, the second diffraction element is used to split the rectangular light spot to form a plurality of rectangular sub-spots, and the rectangular sub-spots are focused on the photovoltaic cell by the focusing device to etch the photovoltaic cell based on the rectangular sub-spots.

3. The laser etching method capable of changing the etching line width according to claim 2, characterized in that: The spacing between the rectangular sub-light spots is also adjusted by the second rotating device.

4. The laser etching method capable of changing etching line width according to claim 1, characterized in that: Before the laser beam is diffracted by the first diffraction element, the laser beam is also shaped by a beam adjuster, and the beam adjuster includes at least one of a beam converter, a shape shaping device, a divergence angle control device or a spatial light modulator.

5. The laser etching method capable of changing etching line width according to claim 3, characterized in that: The first rotating device and the second rotating device are hollow rotating motors.

6. A laser etching device capable of changing the etching line width, characterized in that: include: a light source for emitting a laser beam; a first diffraction element, used for diffracting the laser beam emitted by the light source to obtain a rectangular light spot; a first rotating device, used for rotating the first diffractive element to adjust the projection width of the rectangular light spot in a preset etching direction, wherein the first rotating device is disposed on the first diffractive element; A focusing device is used to focus the rectangular light spot on a photovoltaic cell to etch the photovoltaic cell.

7. The laser etching device capable of changing etching line width according to claim 6, characterized in that: It also includes a second diffraction element arranged between the first diffraction element and the focusing device, the second diffraction element is used to split the rectangular light spot adjusted by the first rotating device to form a plurality of rectangular sub-light spots; the focusing device is used to focus the rectangular sub-light spots on the photovoltaic cell to etch the photovoltaic cell.

8. The laser etching device capable of changing etching line width according to claim 7, characterized in that: It also includes a second rotating device for adjusting the spacing between each of the rectangular sub-spots, and the second rotating device is arranged on the second diffraction element.

9. The laser etching device capable of changing etching line width according to claim 6, characterized in that: A beam adjuster is also arranged between the light source and the first diffraction element. The beam adjuster is used to shape the laser beam. The beam adjuster includes at least one of a beam converter, a shape shaping device, a divergence angle control device or a spatial light modulator.

10. The laser etching device capable of changing etching line width according to claim 8, characterized in that: The first rotating device and the second rotating device are hollow rotating motors.

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