Laser printing device

Abstract

The utility model discloses a laser printing device, the utility model discloses a laser printing device includes: the carrier plate, the lower surface of carrier plate is equipped with the groove, and the electrode slurry is accommodated in the groove, the upper surface of carrier table is equipped with the flexible layer and solar cell piece in proper order, and the fixed frame is fixed with a diaphragm layer in the fixed frame, and the diaphragm layer is located between the carrier plate and solar cell piece, and the diaphragm layer surface is equipped with a plurality of via, in the direction of laser propagation, the projection of groove is in via. The utility model discloses through adding a diaphragm layer with via between the carrier plate and solar cell piece to be able to fast and accurately control the gap size between the carrier plate and solar cell piece, can improve the printing precision and quality of laser printing equipment, also can make laser printing equipment when facing different models of battery piece processing in short -term can switch fast, thereby improve production efficiency.

Description

Technical Field

[0001] This utility model relates to the field of laser printing technology for solar cells, and in particular to a laser printing device. Background Technology

[0002] Laser printing involves using a transparent substrate with grooves cut into its lower surface according to the desired grid line morphology. A paste is then applied to the lower surface of the substrate, filling the grooves. Finally, a silicon wafer is placed beneath the substrate, and a laser beam is used to melt the paste and detach it from the grooves, printing the grid lines onto the wafer. Controlling the gap between the substrate and the silicon wafer is crucial for successful laser printing. A gap that is too large or too small will affect the morphology of the grid lines printed on the wafer surface, thus reducing the yield of the produced solar cells. Furthermore, in existing technologies for laser printing grid lines on large-sized solar cells, the thickness tolerance of the silicon wafer itself also affects the control of the gap between the substrate and the wafer. Utility Model Content

[0003] The main purpose of this invention is to design a laser printing device that can overcome the problem of gap control between the carrier and the silicon wafer, achieve stable printing quality, and be applicable to large-size silicon wafers.

[0004] This utility model proposes a laser printing device, which includes: a carrier plate, the lower surface of which has grooves and the grooves contain electrode paste; a stage, the upper surface of which is sequentially provided with a flexible layer and a solar cell; and a fixing frame, in which a diaphragm layer is fixed, the diaphragm layer is located between the carrier plate and the solar cell, the surface of the diaphragm layer is provided with a plurality of through holes communicating with the grooves and the solar cell, and the vertical projection of the grooves is in the through holes.

[0005] In one embodiment, the platform is vertically and retractably positioned below the diaphragm layer.

[0006] In one embodiment, the diaphragm layer is horizontally arranged, and the periphery of the diaphragm layer is fixed within the fixing frame, and the diaphragm layer is set to a tensioned state.

[0007] In one embodiment, the membrane layer is made of metal or polymer material.

[0008] In one embodiment, the thickness of the diaphragm layer is 5 μm to 35 μm.

[0009] In one embodiment, the thickness tolerance of the diaphragm layer is within 10 μm.

[0010] In one embodiment, the thickness of the diaphragm layer is greater than the height of the gate line obtained by laser printing (0 μm to 10 μm).

[0011] In one embodiment, there are multiple vias and multiple grooves, and the vias and grooves correspond one-to-one in the vertical direction.

[0012] In one embodiment, the projection of the trench onto the diaphragm layer is located within the corresponding via of the diaphragm layer.

[0013] In one embodiment, the distance between the edge of the projection of the trench and the edge of the corresponding via is 10 μm to 100 μm.

[0014] In one embodiment, the flexible layer is bonded to the upper surface of the stage.

[0015] In one embodiment, the thickness of the flexible layer is 0.5 mm to 3 mm.

[0016] In one embodiment, the flexible layer is made of any one of EVA sponge, PU cotton, or silicone film.

[0017] In one embodiment, the trench is elongated, and the via is correspondingly elongated.

[0018] In one embodiment, the carrier plate, the platform, and the fixing frame are configured as square.

[0019] This invention discloses a laser printing device. By adding a perforated diaphragm layer between the carrier plate and the solar cell, the gap between them can be quickly and precisely controlled. This improves the printing accuracy and quality of the laser printing equipment and allows for rapid switching between different types of solar cells, thereby increasing production efficiency. Furthermore, this invention utilizes a resilient diaphragm layer and a flexible layer between the solar cell and the carrier. Because the diaphragm layer, solar cell, and flexible layer all possess a degree of flexibility, their overlapping and compression process further enhances the uniformity of the gaps between them, thus improving the printing quality of the grid lines on the solar cell surface. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a side view of the laser printing apparatus of Embodiment 1 of this utility model;

[0022] Figure 2 This is a top view of the fixing frame in Embodiment 1 of this utility model;

[0023] Figure 3 This is a top view of the carrier plate in Embodiment 1 of this utility model;

[0024] Figure 4 This is a schematic diagram of the projection of the groove in Embodiment 1 of this utility model onto the diaphragm layer. Attached image description:

[0026] 1. Carrier plate; 2. Groove; 3. Fixing frame; 4. Divider layer; 5. Solar cell; 6. Flexible layer; 7. Stage; 8. Via.

[0027] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

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

[0029] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0030] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0031] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0032] The technical problem solved by this invention is that the distance between the carrier plate and the silicon wafer during laser printing affects the width, height, and breakage of the final laser-printed grid lines. Therefore, controlling the gap between the carrier plate and the silicon wafer is a key factor for successful printing. If the gap between the carrier plate and the silicon wafer is too small, there will not be enough space for the gas generated by the laser irradiation of the paste to be released in time. The resulting gas pressure will squeeze the grid lines wider and flatter, making it impossible to achieve ultra-fine grids with a high aspect ratio. If the gap between the carrier plate and the silicon wafer is too large, the paste will be torsional and deformed due to air disturbance after detaching from the carrier plate, causing deformation of the printed grid lines. Both of these phenomena will lead to the scrapping of the laser-printed solar cells. In addition, in the prior art, the larger the silicon wafer size, the greater its thickness tolerance. Due to processing tolerances and assembly tolerances, it is difficult to achieve uniform gap control for large areas (such as 200mm×200mm) in the prior art. Moreover, the accuracy of the processing gap is easily affected by various factors such as temperature and pressure, resulting in unstable printing quality.

[0033] To address the aforementioned issues and achieve precise control over the processing gap between large-size silicon wafers and the carrier substrate, thereby improving the grid line printing quality and product yield on the surface of solar cells.

[0034] This utility model proposes a laser printing device, which includes: a carrier plate 1, the lower surface of which is provided with a groove 2, the groove 2 containing electrode paste; a stage 7, the upper surface of which is provided with a flexible layer 6 and a solar cell 5; and a fixing frame 3, in which a diaphragm layer 4 is fixed, the diaphragm layer 4 being located between the carrier plate 1 and the solar cell 5, the surface of the diaphragm layer 4 being provided with a plurality of through holes communicating with the groove 2 and the solar cell 5, the vertical projection of the groove 2 being within the through holes 2.

[0035] It should be noted that, in the specific implementation of the laser printing device of this utility model, by controlling the stage 7 to form a negative pressure on its upper surface, a flexible layer 6 is adhered under the action of adhesive and fully unfolded to make its surface wrinkle-free. Then, the solar cell 5, the fixing frame 3, and the carrier plate 1 coated with electrode paste are placed in sequence. The stage 7 is controlled to rise so that the solar cell 5 is in contact with the separator layer 4 in the fixing frame 3, and at the same time, the separator layer 4 in the fixing frame 3 is also in contact with the carrier plate 1 coated with electrode paste. Under the irradiation of the laser above the carrier plate 1, the electrode paste in the groove 2 of the carrier plate 1 melts and detaches from the groove 2, passes through the through holes 8 of the separator layer 4, and falls onto the surface of the solar cell 5 to form grid electrodes. Therefore, the thickness of the separator layer 4 is approximately equal to the gap between the carrier plate 1 and the solar cell 5. Since the membrane layer 4, the flexible layer 6, and the solar cell 5 all have a certain degree of flexibility, the gap between them will remain more uniform after they are stacked together and compressed. The thickness of the membrane layer 4 is closer to the gap between the carrier plate 1 and the solar cell 5. Therefore, in actual operation, only the thickness of the membrane layer 4 needs to be controlled to control the gap between the carrier plate 1 and the solar cell 5.

[0036] In one embodiment, the platform 7 is vertically and flexibly positioned below the diaphragm layer 4.

[0037] In one embodiment, the upper surface of the separator layer 4 is attached to the lower surface of the carrier plate 1; the lower surface of the separator layer 4 is attached to the upper surface of the solar cell 5.

[0038] It should be noted that by bonding the carrier plate 1, the separator layer 4, and the solar cell 5 together, the through holes 8 in the separator layer 4 become channels for the electrode paste to fall into the grooves 2 of the carrier plate 1, thus avoiding lateral air disturbance and preventing the grid lines from twisting and deforming due to air disturbance. Simultaneously, the thickness of the separator layer 4 is approximately equal to the gap between the carrier plate 1 and the solar cell 5. During equipment assembly, it is only necessary to place the separator layer 4 corresponding to the grid line height between the carrier plate 1 and the solar cell 5 and ensure tight bonding to complete the assembly. The operation is simple and convenient, significantly improving production efficiency. Compared to related technologies that adjust the distance between the platform 7 and the solar cell 5 using an adjusting screw, the adjustment method of the device in this invention is simpler and faster, and it also avoids the undesirable phenomenon of grid line twisting and deformation caused by air disturbance.

[0039] In one embodiment, the diaphragm layer 4 is horizontally arranged, and the fixing frame 3 applies a uniform tension force to the periphery of the diaphragm layer 4, so that the diaphragm layer 4 is in a tensioned state.

[0040] It should be noted that the membrane layer 4 is attached to the carrier plate 1 and the solar cell 5 and is horizontally arranged. The fixing frame 3 supports the membrane layer 4. The fixing frame 3 is located on the periphery of the membrane layer 4 and applies tension to the membrane layer 4, so that the membrane layer 4 is in a taut state and its surface is wrinkle-free, thereby making the thickness of the membrane layer 4 more uniform. By reducing the thickness tolerance of the membrane layer 4, the precise control of the gap between the carrier plate 7 and the solar cell 5 is further improved.

[0041] In one embodiment, the membrane layer 4 is made of metal or polymer material.

[0042] It should be noted that the diaphragm layer 4 can be made of metal, in which case the diaphragm layer 4 is a metal foil; specifically, the diaphragm layer 4 can be made of copper, aluminum, stainless steel, etc.; preferably, the diaphragm layer 4 is stainless steel foil, as stainless steel has a higher elastic modulus and is less prone to elastic deformation under stress. When the platform 7 rises and extrudes the flexible layer 6, the diaphragm layer 4 made of stainless steel foil is less prone to elastic deformation, thus preventing changes in thickness. The diaphragm layer 4 can also be made of polymer materials, in which case the diaphragm layer 4 is a polymer film; specifically, the diaphragm layer 4 can be made of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), etc.

[0043] In one embodiment, the thickness of the membrane layer 4 is 5 μm to 35 μm.

[0044] It should be noted that the thickness of the separator layer 4 depends on the height of the printed grid lines. The existing requirements for the grid line height are all below 20μm. Therefore, the thickness of the separator layer 4 cannot be too high, to prevent the thickness tolerance from becoming too large due to excessive thickness, which would affect the precise control of the gap between the carrier stage 7 and the solar cell 5.

[0045] In one embodiment, the thickness tolerance of the membrane layer 4 is within 10 μm.

[0046] Specifically, the thickness tolerance of the separator layer 4 is within ±5 μm of the theoretical value. By strictly controlling the thickness tolerance of the separator layer 4, the uniformity of the gap between the carrier plate 1 and the solar cell 5 is further improved, thereby resulting in a better morphology of the grid lines obtained by laser printing. Controlling the thickness tolerance of the separator layer 4 helps to maintain the parallelism between the stage 7 and the solar cell 5 in an ideal state.

[0047] In one embodiment, the thickness of the diaphragm layer 4 is greater than the height of the laser-printed gate lines by 0 μm to 10 μm.

[0048] It should be noted that the thickness of the separator layer 4 depends on the height of the printed grid lines. The thickness tolerance of the separator layer 4 affects the gap tolerance between the carrier plate 1 and the solar cell 5. Therefore, controlling the thickness of the separator layer 4 to be slightly greater than the height of the printed grid lines can effectively prevent the phenomenon that the gas generated by the laser irradiation of the paste cannot be released in time due to insufficient space between the carrier plate 1 and the solar cell 5, and the resulting gas pressure will squeeze the grid lines to become wider and flatter, thereby ensuring that the grid lines have a high aspect ratio.

[0049] In one embodiment, there are multiple vias 8 and multiple grooves 2, and the vias 8 and the grooves 2 correspond one-to-one in the vertical direction.

[0050] It should be noted that the vias 8 in the diaphragm layer 4 are channels for the electrode paste to fall into the grooves 2 of the carrier plate 1, which can avoid lateral air disturbance and thus prevent the grid lines from twisting and deforming due to air disturbance. Therefore, the vias 8 in the diaphragm layer 4 must correspond one-to-one with all the grooves 2 in the carrier plate 1. In actual operation, the vias 8 with precise size and uniform distribution can be obtained by using laser processing on the diaphragm layer 4.

[0051] It should also be noted that by setting through holes 8 on the diaphragm layer 4 that correspond one-to-one with the grooves 2 on the carrier plate 1, the electrode paste in each groove 2 only passes through the corresponding through hole 8, thereby effectively preventing the electrode paste from falling in a deviated direction due to excessive air pressure in the groove 2 or other reasons, which would affect the printing quality of the paste in other grooves 2.

[0052] In one embodiment, reference is made to Figure 4 The distance d between the edge of the projection of the trench 2 and the edge of the corresponding via 8 is 10μm to 100μm. It should also be noted that the distance d between the edge of the projection and the edge of the corresponding via 8 depends on the distance between adjacent trenches 2 on the carrier plate 1. At the same time, it is also necessary to consider the slight displacement of the electrode paste on the surface of the solar cell due to the air pressure in the trench 2 or other reasons. By adopting the above technical solution, it is ensured that all the electrode paste in the trench 2 falls into the surface of the solar cell 5 and does not stick to the sidewall of the via 8 in the separator layer 4.

[0053] In one embodiment, the flexible layer 6 is bonded to the upper surface of the stage 7. It should be noted that the stage 7 is an adsorption stage 7, and its upper surface has multiple adsorption holes. By creating a negative pressure inside the stage 7 and controlling the uniform suction force of each adsorption hole, the flexible layer 6 bonded to the upper surface of the stage 7 is further unfolded under the suction force of the stage 7, maintaining a fully unfolded state with no wrinkles. This helps to control the uniform thickness of the flexible layer 6 in the unfolded state and reduce the thickness tolerance of the flexible layer 6.

[0054] In one embodiment, the flexible layer 6 is made of any one of EVA sponge, PU cotton, or silicone film.

[0055] In one embodiment, the thickness of the flexible layer 6 is 0.5 mm to 3 mm.

[0056] It should be noted that if the thickness of the flexible layer 6 is too large, it will be difficult to control the thickness tolerance of the flexible layer 6. If the thickness is too small, it will easily damage the solar cell 5 when the platform 7 rises and squeezes it. Therefore, it is necessary to control the thickness of the flexible layer 6 to a suitable state so as to achieve the technical effect of maintaining a relatively uniform gap.

[0057] In one embodiment, the trench is elongated, and the via is correspondingly elongated.

[0058] In one embodiment, the carrier plate, the platform, and the fixing frame are configured as square.

[0059] The present invention will be further described below through specific embodiments:

[0060] Example 1

[0061] Reference Figure 1 The laser printing apparatus in Example 1 includes a carrier plate 1, the lower surface of which is provided with grooves 2, the grooves 2 containing electrode paste, as shown in the figure. Figure 2 The trench 2 has a width of 15μm, a depth of 15μm, and a spacing of 0.6mm between trenches. A laser emitter is also provided above the carrier plate 1, which emits a laser from top to bottom through the carrier plate 1 to hit the electrode paste in the trench 2.

[0062] A flexible layer 6 is provided on the upper surface of the stage 7. The flexible layer 6 is made of EVA foam and has a thickness of 2mm. A solar cell 5 with a size of 183mm*182mm is placed on the upper surface of the flexible layer 6.

[0063] A fixing frame 3 is provided between the carrier plate 1 and the stage 7. A diaphragm layer 4 is fixed inside the fixing frame 3. The perimeter of the diaphragm layer 4 is fixed inside the fixing frame 3, is in a taut state, and keeps its surface wrinkle-free.

[0064] In Example 1, the separator layer 4 is made of stainless steel foil with a thickness of 20 μm. The separator layer 4 is horizontally disposed between the carrier plate 1 and the stage 7, and the carrier plate 1, separator layer 4, and solar cell 5 are all arranged in parallel. (Refer to...) Figure 3 The diaphragm layer 4 is also provided with through holes 8, the number and position of which are related to... Figure 2 The number and position of the grooves 2 on the lower surface of the intermediate plate 1 correspond one-to-one.

[0065] Reference Figure 4It can be seen that the vias 8 in the diaphragm layer 4 and the grooves 2 on the carrier plate 1 are in a one-to-one correspondence in position, and the distance d between the edge of the projection of the groove 2 in the via and the edge of the corresponding via 8 is 50μm.

[0066] In operation, the stage 7 is raised to bring the solar cell 5 into contact with the separator layer 4 within the fixing frame 3. Simultaneously, the separator layer 4 within the fixing frame 3 is also in contact with the carrier plate 1 coated with electrode paste. Under the irradiation of a laser above the carrier plate 1, the electrode paste in the trenches 2 of the carrier plate 1 melts, detaches from the trenches 2, passes through the through-holes 8 of the separator layer 4, and falls onto the surface of the solar cell 5 to form grid electrodes. The average height of the resulting grid electrodes is approximately 12 μm, and the average width of the grid lines is approximately 14 μm.

[0067] In summary, the laser printing device of this invention has a simple structure. By setting the diaphragm layer and the flexible layer, it can quickly and accurately control the gap between the carrier plate and the solar cell. This not only improves the printing accuracy and quality of the laser printing equipment, but also enables the laser printing equipment to quickly switch between processing different types of solar cells in a short period of time, thereby improving production efficiency.

[0068] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A laser printing apparatus, characterized in that, The laser printing apparatus includes: A carrier plate, the lower surface of which is provided with grooves, the grooves containing electrode paste; A platform, the upper surface of which is sequentially provided with a flexible layer and solar cells; and A fixed frame is provided, and a diaphragm layer is fixed inside the fixed frame. The diaphragm layer is located between the carrier plate and the solar cell. The surface of the diaphragm layer is provided with a plurality of through holes that connect the groove and the solar cell. The vertical projection of the groove is in the through holes.

2. The laser printing apparatus as described in claim 1, characterized in that, The platform is vertically movable and located below the diaphragm layer.

3. The laser printing apparatus as described in claim 1, characterized in that, The diaphragm layer is horizontally arranged, and its perimeter is fixed within the fixing frame. The diaphragm layer is set to a tensioned state.

4. The laser printing apparatus as described in claim 1, characterized in that, The membrane layer is made of metal or polymer material; And / or, the thickness of the diaphragm layer is 5 μm to 35 μm; And / or, the thickness tolerance of the diaphragm layer is within 10 μm.

5. The laser printing apparatus as described in claim 1, characterized in that, The thickness of the diaphragm layer is greater than the grid line height obtained by laser printing by 0 μm to 10 μm.

6. The laser printing apparatus as described in claim 1, characterized in that, There are multiple vias and multiple grooves, and the vias and grooves correspond one-to-one in the vertical direction.

7. The laser printing apparatus as described in claim 1, characterized in that, The distance between the edge of the trench projection and the edge of the corresponding via is 10μm to 100μm.

8. The laser printing apparatus as described in claim 1, characterized in that, The flexible layer is bonded to the upper surface of the stage.

9. The laser printing apparatus as described in claim 1, characterized in that, The thickness of the flexible layer is 0.5 mm to 3 mm; And / or, the material of the flexible layer is selected from any one of EVA sponge, PU cotton, and silicone film.

10. The laser printing apparatus as claimed in claim 1, characterized in that, The groove is elongated, and the via is correspondingly elongated. And / or, the carrier plate, the platform, and the fixing frame are configured as square.

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