Printing carrier plate and photovoltaic cell
By introducing metal or polymer film layers onto photovoltaic cell printing substrates, the problem of trench edge chipping is solved, improving substrate quality and photovoltaic cell performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN AIPYANG LASER TECHNOLOGY CO LTD
- Filing Date
- 2025-04-28
- Publication Date
- 2026-05-15
AI Technical Summary
Existing photovoltaic cell printed substrates are prone to groove edge chipping during the groove processing, which affects the quality of the grid lines.
The printed substrate employs a metal film layer or a polymer film layer. The metal film layer has excellent thermal conductivity and mechanical support, while the polymer film layer can reflect or absorb laser energy, reducing local temperature gradients and stress concentration, and minimizing microcracks and chipping caused by thermal stress.
It improves the quality of the carrier plate grooves, reduces microcracks and chipping caused by thermal stress, enhances the mechanical strength and service life of the carrier plate, reduces production costs, and improves the photoelectric conversion efficiency of photovoltaic cells.
Smart Images
Figure CN224240633U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic cell technology, and in particular to a printed substrate and a photovoltaic cell. Background Technology
[0002] A photovoltaic cell is a semiconductor device that uses the photoelectric effect to convert solar energy into electrical energy. It generates current through photoelectric materials and collects and transmits the current through grid lines.
[0003] Grid lines are conductive structures set on the surface of photovoltaic cells and can be formed using laser printing technology. Laser printing technology uses a high-precision laser to create grooves on a transparent substrate (such as glass) to fill with conductive paste, which is then transferred to the surface of the cell to form grid lines.
[0004] However, the substrates currently used in laser printing technology are made of transparent and brittle materials. During the processing of grooves, the edges of the grooves may chip, which affects the quality of the grid lines. Utility Model Content
[0005] The main purpose of this invention is to propose a printed substrate and a photovoltaic cell, which aims to improve the quality of the substrate grooves.
[0006] In a first aspect, the present invention provides a printing carrier plate, including a carrier plate body and a film layer disposed on at least one side surface of the carrier plate body, the film layer including at least one of a metal film layer and a polymer film layer; the printing carrier plate further includes a groove array, which penetrates the film layer and extends to the carrier plate body along the thickness direction of the printing carrier plate.
[0007] In one embodiment, the damage threshold of the metal film is 1×10⁻⁶. 4 W / cm 2 -1×10 7 W / cm 2 .
[0008] In one embodiment, the metal film layer includes one of a titanium layer, an aluminum layer, and a chromium layer.
[0009] In one embodiment, the thickness of the metal film is 50nm-100nm.
[0010] In one embodiment, the polymer film layer includes one of a polyester film layer and a polyimide film layer.
[0011] In one embodiment, the thickness of the polymer film is 50 μm-100 μm.
[0012] In one embodiment, the trench array includes a plurality of trenches arranged in sequence, the width of which is 2μm-10μm.
[0013] In one embodiment, the depth of the groove on the carrier plate body is 20μm-100μm.
[0014] In one embodiment, the longitudinal section of the trench includes one of trapezoidal, triangular, and arched shapes.
[0015] Secondly, this utility model provides a photovoltaic cell, including a cell and grid lines disposed on the surface of the cell, wherein the grid lines are manufactured by any of the aforementioned printed circuit boards.
[0016] The printing substrate of this invention comprises a metal film layer or a polymer film layer. When a groove array is fabricated on the printing substrate using laser etching, the metal film layer exhibits excellent thermal conductivity, enabling rapid diffusion of laser heat and reducing the local temperature gradient of the substrate, thereby minimizing microcracks and chipping caused by thermal stress. Furthermore, the metal film layer provides additional mechanical support to the substrate surface during processing, inhibiting the propagation of microcracks. The ductility of the metal absorbs or disperses the stress generated by laser impact, alleviating stress concentration in brittle glass and further reducing edge chipping. The polymer film layer can partially reflect or absorb laser energy, reducing the instantaneous temperature rise of the substrate surface and thus minimizing cracking caused by thermal stress. Therefore, the printing substrate of this invention improves the quality of the substrate grooves. Attached Figure Description
[0017] To more clearly illustrate the embodiments of this utility model, the accompanying drawings used in the description of the embodiments 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.
[0018] Figure 1 This is a top view of a printing carrier plate in one embodiment of the present invention;
[0019] Figure 2 This is a side sectional view of the printing carrier plate in one embodiment of the present invention.
[0020] Explanation of icon numbers
[0021] 100. Printed substrate; 11. Substrate body; 12. Film layer; 13. Groove array; 131. Groove. Detailed Implementation
[0022] It should be noted that if the embodiments of this utility model involve descriptions such as "first" or "second," these 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. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the use of "and / or" or "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied. In the embodiments of this utility model, "at least one" refers to one or more, and "more" refers to two or more.
[0023] The "range" disclosed in this utility model is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. The range defined in this way can include or exclude end values, and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range.
[0024] 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.
[0025] Laser printing technology uses a high-precision laser to create grooves on a transparent substrate (such as glass) to fill with conductive paste, which is then transferred to the surface of a solar cell to form grid lines. Due to the brittle nature of glass, when the laser concentrates energy instantaneously (nanosecond to femtosecond levels) into an extremely small area, the local temperature of the glass rises sharply (up to thousands of degrees Celsius), followed by a large temperature gradient due to the rapid cooling of the surrounding materials. When the glass expands due to heat, it is constrained by the surrounding cold areas, generating tensile stress; when it cools, it contracts, creating reverse stress. When this alternating stress exceeds the tensile strength of the glass, it can cause the edges to crack.
[0026] To reduce the problem of chipping at the groove edges, this utility model provides a printing substrate 100, for reference. Figure 1 and 2 As shown, the substrate includes a carrier body 11 and a film layer 12 disposed on at least one side surface of the carrier body 11. The film layer 12 includes at least one of a metal film layer and a polymer film layer. The printing carrier 100 also includes a trench array 13, which penetrates the film layer 12 and extends to the carrier body 11 along the thickness direction of the printing carrier 100.
[0027] The carrier body 11 refers to the carrier used to hold the conductive silver paste, which is specifically filled in the trench array 13. The carrier body 11 is a transparent rigid carrier, which has high mechanical strength and can improve the service life of the printing carrier 100. In some embodiments, the carrier body 11 may include a glass-based light-transmitting plate or a polymer-based light-transmitting plate. The glass-based light-transmitting plate may be quartz glass or ordinary glass, and the polymer-based light-transmitting plate may be a rigid plastic plate or a high-polymerization polymer plate.
[0028] by Figure 2 For example, the film layer 12 is disposed on one side surface of the carrier plate body 11, and correspondingly, the groove array 13 is also located on the side surface where the film layer 12 is disposed, that is, the printing carrier plate 100 is a single-sided printing carrier plate. In some other embodiments, the film layer 12 can also be disposed on both sides surface of the carrier plate body 11, and correspondingly, the groove array 13 is provided on both sides surface, in which case the printing carrier plate 100 is a double-sided printing carrier plate.
[0029] The thermal conductivity of the metal film layer is significantly better than that of the carrier plate 11. When the laser acts on the metal film layer, the heat can be rapidly dissipated, reducing the local temperature gradient of the carrier plate 11 and thus reducing microcracks and chipping caused by thermal stress. This efficient heat conduction avoids the drastic expansion and contraction of the carrier plate 11 caused by rapid heating and cooling. In addition, the metal film layer provides additional mechanical support to the surface of the carrier plate 11 during processing, which can suppress the propagation of microcracks. The ductility of the metal can also absorb or disperse the stress generated by the laser shock, alleviating the stress concentration phenomenon of the brittle carrier plate 11, thereby further reducing edge chipping.
[0030] The present invention does not specifically limit the method for forming a metal film layer on the surface of the carrier plate 11. In some embodiments, the metal film layer can be formed on the surface of the carrier plate 11 by electroplating, vacuum evaporation coating, sputtering coating, chemical vapor deposition, electroless plating, etc. Compared with polymer film layers, the metal film layer formed by the above methods has higher flatness and better uniformity.
[0031] The polymer film can partially reflect or absorb laser energy, reducing the instantaneous temperature rise on the surface of the carrier plate 11, thereby reducing cracking caused by thermal stress. The polymer film can be fixed to the surface of the carrier plate 11 by adhesive bonding. Both the polymer film and the metal film serve as sacrificial layers to reduce edge chipping at the groove edges. After grooving is completed, these films need to be removed; otherwise, they will affect the coating effect of the subsequent printing paste. The polymer film can be directly peeled off, offering the advantage of easy removal.
[0032] The trench array 13 refers to a group of trenches arranged according to certain rules such as row and column order, spacing, and direction. Figure 1For example, multiple grooves are arranged along the X direction, and each groove extends along the Y direction, with the X and Y directions being perpendicular.
[0033] refer to Figure 2 As shown, the thickness direction of the printing substrate 100 refers to... Figure 2 In the Z direction shown, the trench array 13 penetrates the film layer 12 and extends to the carrier plate body 11, meaning that the trench depth of the trench array 13 is greater than the thickness of the film layer 12.
[0034] According to some embodiments of this invention, the damage threshold of the metal film is 1×10⁻⁶. 4 W / cm 2 -1×10 7 W / cm 2 .
[0035] The damage threshold of a metal film is the laser-induced damage threshold (LIDT), which is an important parameter for measuring its resistance to damage under laser irradiation. It is usually tested in accordance with the ISO 21254 series of standards ("Test method for laser-induced damage threshold").
[0036] When the groove array 13 is fabricated on the carrier plate 11, the energy density of the laser beam focused on the surface of the carrier plate 11 exhibits a Gaussian distribution, with strong energy at the center and gradually weakening away from the laser center. The damage threshold of the metal film layer is 1×10⁻⁶. 4 W / cm 2 -1×10 7 W / cm 2 When the energy value is higher than the edge energy value of the laser beam, the beam outside this critical value cannot damage the carrier plate body 11, thus effectively protecting the edge of the groove and reducing the occurrence of groove chipping.
[0037] According to some embodiments of the present invention, the metal film layer includes one of a titanium layer, an aluminum layer, and a chromium layer.
[0038] The damage threshold of the titanium layer is 3-7×10 4 W / cm 2 The damage threshold of the aluminum layer is between 2 and 5 × 10⁻⁶. 4 W / cm 2 The damage threshold of the chromium layer is between 5 and 12 × 10⁻⁶. 4 W / cm 2 Between. Titanium, aluminum, and chromium layers can all effectively reduce chipping at the trench edges during laser etching.
[0039] According to some embodiments of this utility model, the thickness of the metal film layer is 50nm-100nm.
[0040] For example, the thickness of the metal film can be 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, or 100nm. When the thickness of the metal film is between 50nm and 100nm, it helps to form a continuous thin film, which can effectively disperse heat through high thermal conductivity, reduce local thermal stress in the glass, and thus reduce the problem of edge chipping in the trench array.
[0041] According to some embodiments of the present invention, the polymer film layer includes one of a polyester film layer and a polyimide film layer.
[0042] Polyester film refers to a film layer formed primarily from polyethylene terephthalate (PET). Polyester and polyimide films exhibit high absorption rates for lasers of specific wavelengths (such as ultraviolet or near-infrared). When laser light strikes the polyester film layer, its energy is first absorbed and converted into heat, reducing the proportion of energy directly transferred to the carrier substrate 11. This process lowers the instantaneous temperature peak on the surface of the carrier substrate 11, thereby mitigating thermal stress concentration and helping to reduce chipping at the groove edges. In some embodiments, the polyester film layer can be a biaxially oriented polyester film layer (APET film layer). The biaxial stretching process orients the PET molecular chains in two mutually perpendicular directions, thereby improving the mechanical strength and other properties of the polyester film.
[0043] According to some embodiments of this utility model, the thickness of the polymer film is 50μm-100μm.
[0044] For example, the thickness of the polymer film can be 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, or 100μm. When the thickness of the polymer film is between 50μm and 100μm, the film is relatively thick, exceeding the focal depth of the laser system's focusing lens. This further weakens the edge etching capability of the Gaussian beam in the defocused state. Therefore, the polymer film on both sides of the trench will remain, which can buffer the plasma impact generated during subsequent etching, thereby reducing the stress directly acting on the trench edge and further reducing the problem of trench edge chipping.
[0045] According to some embodiments of the present invention, the trench array 13 includes a plurality of trenches 131 arranged in sequence, and the width of the trenches 131 is 2μm-10μm.
[0046] by Figure 1For example, the width of trench 131 is its dimension in the X direction. Exemplarily, the width of trench 131 can be 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, or 10μm. When the width of trench 131 is between 2μm and 10μm, grid lines with a width of 2μm to 10μm can be formed. On the one hand, this reduces the amount of conductive silver paste used, lowering the production cost of photovoltaic cells; on the other hand, grid lines with a width of 2μm to 10μm can reduce shading of the solar cells, thereby reducing the impact on the light incident rate of the photovoltaic cells, and thus helping to improve the overall photoelectric conversion efficiency of the photovoltaic cells.
[0047] According to some embodiments of the present invention, the depth of the groove 131 on the carrier plate body 11 is 20μm-100μm.
[0048] by Figure 2 For example, the depth of trench 131 on the carrier plate body 11 refers to the dimension of trench 131 in the Z direction of the carrier plate body 11. For example, the depth of trench 131 on the carrier plate body 11 can be 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm. When the depth of trench 131 on the carrier plate body 11 is between 20μm and 100μm, a higher grid line can be formed, which helps to reduce resistance loss, improve current collection efficiency, and the higher grid line can collect current more uniformly, reducing the phenomenon of excessively high local current density, thereby reducing the risk of hot spot effect (local overheating) and helping to improve the long-term reliability of photovoltaic cells.
[0049] According to some embodiments of the present invention, the longitudinal section of the trench 131 includes one of trapezoidal, triangular, and arched shapes.
[0050] According to some embodiments of the present invention, the present invention also provides a photovoltaic cell, including a cell and grid lines disposed on the surface of the cell, wherein the grid lines are fabricated using any of the above-mentioned printed circuit boards.
[0051] 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 printing substrate, characterized in that, It includes a carrier plate body and a film layer disposed on at least one surface of the carrier plate body, wherein the film layer includes at least one of a metal film layer and a polymer film layer; The printing substrate further includes a groove array that extends through the film layer and onto the substrate body along the thickness direction of the printing substrate.
2. The printing substrate as described in claim 1, characterized in that, The damage threshold of the metal film is 1×10⁻⁶. 4 W / cm 2 -1×10 7 W / cm 2 .
3. The printing substrate as described in claim 1, characterized in that, The metal film layer includes one of a titanium layer, an aluminum layer, and a chromium layer.
4. The printing substrate as described in any one of claims 1 to 3, characterized in that, The thickness of the metal film is 50nm-100nm.
5. The printing substrate as described in claim 1, characterized in that, The polymer film layer includes one of a polyester film layer and a polyimide film layer.
6. The printing substrate as described in claim 1 or 5, characterized in that, The thickness of the polymer film is 50μm-100μm.
7. The printing substrate as described in claim 1, characterized in that, The trench array comprises a plurality of trenches arranged in sequence, the width of which is 2μm-10μm.
8. The printing substrate as described in claim 7, characterized in that, The depth of the groove on the carrier plate body is 20μm-100μm.
9. The printing substrate as described in claim 7, characterized in that, The longitudinal section of the trench includes one of the following: trapezoidal, triangular, or arched.
10. A photovoltaic cell, characterized in that, It includes a solar cell and grid lines disposed on the surface of the solar cell, the grid lines being manufactured using a printed circuit board as described in any one of claims 1 to 9.