Laser transfer printing glass substrate
By designing a laser transfer glass substrate consisting of a first glass plate with a thickness of 0.3–2 mm and a second glass plate with a thickness of 2–10 mm, the problems of limited reusability of plastic film substrates and easy damage to thick glass are solved, achieving a high-efficiency and low-cost laser transfer effect.
Patent Information
- Application Number
- CN202520426104.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-12
- Publication Date
- 2026-01-06
- Estimated Expiration
- 2035-03-12
AI Technical Summary
In existing laser transfer technologies, plastic film substrates have limited reusability and high costs, while thick glass substrates are easily damaged during groove processing, making it difficult to meet the demand for efficient and low-cost laser transfer.
A laser transfer glass substrate is used, consisting of a first glass plate with a thickness of 0.3 to 2 mm and a second glass plate with a thickness of 2 to 10 mm. The first glass plate has grooves, and the two are fixed together by a fixed connection or an adhesive layer to increase the thickness of the substrate and improve its strength. The grooves are processed by laser-induced etching to ensure machinability and precision.
This improves the strength of laser-transfer glass substrates, prevents damage, reduces substrate loss costs, and enhances the efficiency and precision of laser transfer.
Smart Images
Figure CN223764049U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of laser transfer technology, and specifically relates to a laser transfer glass substrate. Background Technology
[0002] As an electrode fabrication technology for photovoltaic cells, laser transfer printing is a novel non-contact printing technique that can improve the light conversion efficiency of solar cells by 0.1-0.2%, save 20%-30% of the silver paste used for sub-busbars, and achieve excellent uniformity and height consistency of the busbars. It is also highly versatile, being unrestricted by paste type (silver paste, silver-coated copper) and cell type, and can be used on PERC, Topcon, IBC, and HJT cells. As an emerging electrode metallization replacement technology, laser transfer printing can significantly increase economic benefits for downstream cell customers without increasing investment in production line equipment, and has broad prospects for future industrial application, especially for N-type cells where it significantly reduces costs.
[0003] Currently, laser transfer printing mostly uses plastic film or glass as the substrate for filling and transferring the slurry. Plastic film can only be reused 5-6 times before needing to be scrapped, resulting in high costs. Glass substrates are difficult to manufacture, especially thick glass which is difficult to shape into grooves, while thin glass is easily damaged during the filling process by the squeegee. Utility Model Content
[0004] In view of the above-mentioned defects or improvement needs of the existing technology, this utility model provides a laser transfer glass substrate.
[0005] To achieve the above objectives, this utility model provides a laser transfer glass substrate, comprising a first glass plate and a second glass plate fixedly connected, wherein the thickness of the first glass plate is 0.3-2mm, the thickness of the second glass plate is 2-10mm, and a plurality of grooves are provided on the side of the first glass plate opposite to the second glass plate.
[0006] As a further preferred embodiment of this invention, the transmittance of the first glass plate and the second glass plate to the laser is above 70%.
[0007] As a further preferred embodiment of this invention, the first glass plate is BF33 glass, soda-lime glass, high-alumina glass, or quartz glass.
[0008] As a further preferred embodiment of this invention, the second glass plate is BF33 glass, soda-lime glass, high-alumina glass, or quartz glass.
[0009] As a further preferred embodiment of this utility model, the first glass plate and the second glass plate are in direct contact, and their edges are connected by a fixed frame, clamps or bolts.
[0010] As a further preferred embodiment of this invention, sealant is applied to the edges of the first and second glass plates, and a vacuum is drawn between the first and second glass plates.
[0011] As a further preferred embodiment of this utility model, an adhesive layer is provided between the first glass plate and the second glass plate, the thickness of the adhesive layer is not greater than 1 mm, and / or the transmittance of the adhesive layer to laser is above 70%.
[0012] As a further preferred embodiment of this invention, the adhesive layer is an epoxy resin adhesive, an acrylic resin adhesive, a polyurethane adhesive, or a UV adhesive.
[0013] As a further preferred embodiment of this invention, the flatness of the first glass plate and the second glass plate is within ±100μm.
[0014] As a further preferred embodiment of this invention, the depth of the groove is 5μm to 50μm and the width is 10 to 120μm.
[0015] In summary, the beneficial effects of the above-described technical solutions conceived by this utility model compared with the prior art include:
[0016] The laser transfer glass substrate provided by this utility model has grooves prepared on a relatively thin first glass plate to carry the printing paste, ensuring the machinability and processing accuracy of the grooves. A thicker second glass plate is fixedly connected to the first glass plate, increasing the thickness of the laser transfer glass substrate and ensuring its strength. When the transfer paste is filled into the grooves using a squeegee, the higher strength effectively prevents damage to the laser transfer glass substrate. Attached Figure Description
[0017] Figure 1 This is a cross-sectional schematic diagram of a laser transfer glass substrate according to one embodiment of the present invention;
[0018] Figure 2 This is a top view schematic diagram of a laser transfer glass substrate according to one embodiment of the present invention.
[0019] Figure 3 This is a cross-sectional schematic diagram of a laser transfer glass substrate according to one embodiment of the present invention.
[0020] Figure 4 This is a cross-sectional schematic diagram of a laser transfer glass substrate according to another embodiment of the present invention.
[0021] Figure 5 A schematic diagram showing the filling of slurry in the grooves of the laser transfer glass substrate of this utility model;
[0022] Figure 6A schematic diagram showing laser irradiation of the laser transfer glass substrate of this invention.
[0023] Figure 7 This is a schematic diagram illustrating the process of releasing paste from the grooves of a laser transfer glass substrate onto a silicon wafer to complete the transfer.
[0024] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically:
[0025] 1. First glass plate; 11. Groove; 2. Second glass plate; 3. Adhesive layer; 4. Printing paste; 5. Silicon wafer; 6. Fixing frame. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.
[0027] In the description of this utility model, it should be understood that, unless otherwise stated, the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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.
[0028] Furthermore, unless otherwise stated, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0029] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0030] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0031] This utility model relates to a laser transfer glass substrate, see [link to related document]. Figure 1 It includes a first glass plate 1 and a second glass plate 2 fixedly connected vertically. The thickness of the first glass plate 1 is 0.3-2 mm, and the thickness of the second glass plate 2 is 2-10 mm. The first glass plate 1 has multiple grooves 11 on the side opposite to the second glass plate 2.
[0032] The laser transfer glass substrate provided by this utility model has grooves prepared on a relatively thin first glass plate to carry the printing paste, ensuring the machinability and processing accuracy of the grooves. A thicker second glass plate is fixedly connected to the first glass plate, increasing the thickness of the laser transfer glass substrate and ensuring its strength. When the transfer paste is filled into the grooves using a squeegee, the higher strength effectively prevents damage to the laser transfer glass substrate.
[0033] As laser transfer glass substrates, both the first glass plate 1 and the second glass plate 2 are transparent glass plates, meaning they are transparent to laser light. Specifically, their laser transmittance is 70% or higher, 80% or higher, 90% or higher, 95% or higher, or 98% or higher, etc. Those skilled in the art will understand that the higher the laser transmittance, the better the laser transfer effect.
[0034] The first glass plate 1 has grooves 11, the thickness of which should not be too thick to facilitate the processing of the grooves using laser-induced etching. Specifically, the thickness is 0.3–2 mm, preferably 0.5–1.5 mm. The first glass plate 1 is preferably made of high borosilicate glass, such as BF33 glass, which has almost 100% light transmittance, facilitating laser transfer processing. It also has good heat resistance and a low coefficient of thermal expansion, allowing for long-term laser transfer processing with minimal thermal deformation. Furthermore, it has good chemical resistance, making it easier to achieve good processing accuracy and maintain a low roughness when processing the grooves using laser-induced etching.
[0035] The grooves 11 on the first glass plate 1 can be processed by laser-induced etching. During laser-induced etching, the following method can be used: a laser beam is used to irradiate one side surface of the first glass plate, inducing absorption within the first glass substrate and moving laterally to form a continuous modified grating structure. Taking a Bessel laser beam as an example, the laser energy is 10-300 μJ, the pulse width is less than 20 picoseconds, the spot diameter is 1-10 μm, and the focal depth is 0.2-3 mm. The modified first glass plate is immersed in an etching solution, and the desired grooves are formed by the selective reaction between the acid or alkali etching solution and the modified area. The alkali etching solution includes 20%-40% by mass of a strong alkali and 2%-20% by mass of a complexing agent; the acid etching solution includes 1%-25% by mass of a fluoride and 2%-20% by mass of a mixed acid.
[0036] See Figure 1 and Figure 2 ,in, Figure 2 This is a top view schematic diagram of a laser transfer glass substrate. The diagram shows the surface of the first glass plate with grooves. Typically, for the transfer of paste for photovoltaic cells, the grooves 11 include multiple grooves arranged in parallel. The cross-sectional shape of the grooves 11 can be as follows... Figure 1 The shape shown is an inverted triangle. Other preferred options include inverted trapezoids, trapezoids, rectangles, etc., to accommodate the transfer of different grid line electrodes.
[0037] In order to form different groove shapes (groove cross-sectional patterns), the focal depth and / or energy density distribution of the laser beam's focusing line can be set according to the groove width distribution in the depth direction of the groove to be processed, so that the focusing line has an energy distribution corresponding to the groove width distribution inside the device to be processed, thereby forming a corresponding modification zone, and forming the desired groove shape through etching.
[0038] Preferably, the depth of the groove 11 is 5μm to 50μm, and the width is 10 to 120μm, wherein the width is the width at the opening of the groove cross-section.
[0039] The second glass plate 2 uses a thicker glass plate as a support. It can be the same high borosilicate glass as the first glass plate, such as BF33 glass, or it can be soda-lime glass or high-alumina glass. It has good light transmittance.
[0040] The first glass plate 1 and the second glass plate 2 can also be made of quartz glass, which has excellent laser transmittance.
[0041] The first glass plate 1 and the second glass plate 2 can be in direct contact. In the non-grooved areas at the edges, they can be fixed together using clamps or other fasteners, or secured using fastening devices such as frames or screws. (See also...) Figure 3 , Figure 3 A schematic diagram showing the first glass plate 1 and the second glass plate 2 fixed by a fixed frame 6 is shown.
[0042] At this point, the flatness of both the first glass plate 1 and the second glass plate 2 is within ±100μm, preferably within ±20μm, to ensure good adhesion between them and prevent air scattering of the laser from the air between them, which would affect the processing effect. In some preferred embodiments, sealant is applied to the sides of the first glass plate 1 and the second glass plate 2, and they are fixed by a fixing frame or the like. A vacuum is drawn between the first glass plate 1 and the second glass plate 2 to reduce laser scattering.
[0043] As another possible implementation method, see Figure 4 An adhesive layer 3 is provided between the first glass plate 1 and the second glass plate 2, and the first glass plate 1 and the second glass plate 2 are fixedly connected by the adhesive layer 3. Specifically, the first glass plate 1 and the second glass plate 2 are fixedly connected by using glass adhesive to bond and fix them together. The thickness of the adhesive layer 3 is not less than 1 mm. The adhesive layer 3 has good light transmittance, such as a laser transmittance of 70%, 80%, 90%, or 95% or higher, and is resistant to high temperatures and does not discolor. The adhesive layer 3 can be epoxy resin, acrylic resin, polyurethane resin, or UV adhesive, etc.
[0044] During preparation, epoxy resin adhesive, acrylic resin adhesive, polyurethane resin adhesive, etc. are used to bond the first glass plate and the second glass plate together, and the flatness of the first glass plate and the second glass plate after bonding is maintained, for example within ±100μm, preferably within ±20μm.
[0045] Those skilled in the art will understand that, in order to ensure the flatness of the first and second glass plates, glass prepared by a micro-float process can be selected.
[0046] See Figures 5 to 7When using the laser transfer glass substrate of this invention, the printing paste is first filled into the grooves using a squeegee or paste filler. Figure 4 This is a schematic diagram showing the slurry filling the trench. See also... Figure 5 The laser transfer glass substrate has a grooved surface positioned relative to the silicon wafer. A laser is incident from above the laser transfer glass substrate, irradiating the groove location, releasing the paste in the groove, and transferring it onto the silicon wafer 5 below, thus completing the laser transfer. Figure 7 A schematic diagram illustrating the process of transferring the paste.
[0047] The laser transfer glass substrate provided by this utility model has grooves prepared on a relatively thin first glass plate to carry the printing paste, ensuring the machinability and processing accuracy of the grooves. A thicker second glass plate is fixedly connected to the first glass plate, increasing the thickness of the laser transfer glass substrate and ensuring its strength. When the transfer paste is filled into the grooves using a squeegee, the higher strength effectively prevents damage to the laser transfer glass substrate.
[0048] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A laser transfer glass substrate, characterized by: The first glass plate and the second glass plate are fixedly connected, wherein the thickness of the first glass plate is 0.3-2 mm, the thickness of the second glass plate is 2-10 mm, and a plurality of grooves are arranged on the side of the first glass plate away from the second glass plate.
2. The laser transfer glass substrate of claim 1, wherein: The transmittance of the first glass plate and the second glass plate to laser is above 70%.
3. The laser transfer glass substrate of claim 1, wherein: The first glass plate is BF33 glass, soda-lime glass or high-aluminum glass, or quartz glass.
4. The laser transfer glass substrate of claim 1, wherein: The second glass plate is BF33 glass, soda-lime glass or high-aluminum glass, or quartz glass.
5. The laser transfer glass substrate of claim 1, wherein: The first glass plate and the second glass plate are directly contacted, and the edges are connected by a fixing frame, a clamp or a bolt.
6. The laser transfer glass substrate of claim 5, wherein: Sealing glue is arranged on the edges of the first glass plate and the second glass plate, and the first glass plate and the second glass plate are vacuumized.
7. The laser transfer glass substrate of claim 1 or 5, wherein: An adhesive layer is arranged between the first glass plate and the second glass plate, the thickness of the adhesive layer is not more than 1 mm, and / or the transmittance of the adhesive layer to laser is above 70%.
8. The laser transfer glass substrate of claim 7, wherein: The adhesive layer is an epoxy resin adhesive, an acrylic resin adhesive, a polyurethane adhesive or UV glue.
9. The laser transfer glass substrate of claim 1, wherein: The flatness of the first glass plate and the second glass plate is within ±100 μm.
10. The laser transfer glass substrate of claim 1, wherein: The depth of the groove is 5-50 μm, and the width is 10-120 μm.