Main grid screen printing plate and photovoltaic cell

Abstract

The invention provides a main grid screen printing plate and a photovoltaic cell, the main grid screen printing plate comprises a plurality of fine grids and m main grids intersecting with the fine grids, each main grid comprises a plurality of first bonding pads arranged in the vertical direction of the fine grids, every two first bonding pads are connected through a main grid connecting line, each first bonding pad and n second bonding pads are arranged at intervals in the parallel direction of the fine grids, wherein n is greater than m. On the basis of the mode, the m main grids arranged on the main grid screen plate can meet the cost reduction requirement of battery preparation and also meet the assembly welding tension requirement; moreover, as the main grid can gather the current generated among the fine grids when the reverse bias voltage is applied, and can play a role in preventing the grid from being broken, the fine grids are enabled to generate good ohmic contact, and the electrical performance of the photovoltaic cell is further improved.

Description

Technical Field

[0001] The present invention mainly relates to the field of photovoltaic technology, and in particular to a main grid plate and a photovoltaic cell. Background Art

[0002] In the preparation of batteries, printed screens are often used to form corresponding patterns on the battery surface. In order to achieve the purpose of reducing unit consumption, the commonly used printed screen is a main grid-free screen, which includes a number of horizontally arranged fine grids and a number of alternately arranged pads.

[0003] Due to the limitations of the laser induction process, batteries made with a main-grid-free screen generally have the probe pressed onto the front edge to apply a reverse bias voltage. However, since there is no electrical connection between the fine grids under this design, the current between the fine grids cannot be converged. Once a grid break occurs, the corresponding fine grid will not be able to form a good current loop during laser induction, resulting in the fine grid failing to form a good ohmic contact during laser induction, affecting the electrical performance of the battery. Summary of the invention

[0004] The object of the present invention is to provide a main grid screen and a photovoltaic cell for better matching the laser induction technology and achieving good ohmic contact of the fine grid.

[0005] Based on the above-mentioned purpose, in the first aspect, the present application provides a main grid screen, comprising a plurality of fine grids and m main grids intersecting therewith, wherein each main grid comprises a plurality of first welding pads arranged in a vertical direction of the fine grids, and every two first welding pads are connected by a main grid connecting line, and for each first welding pad, n second welding pads are arranged in a spaced relationship therewith in a direction parallel to the fine grids, wherein n is greater than m.

[0006] In some embodiments, a middle position along the length of the fine gate is divided into a first region and a second region, wherein the first region and the second region are symmetrical to each other.

[0007] In some embodiments, m=2, and n=16.

[0008] In some embodiments, one of the two main gates is disposed at a middle position along the length of the thin gate in the first region, and the other is disposed at a middle position along the length of the thin gate in the second region.

[0009] In some embodiments, a distance between two adjacent first pads along a direction perpendicular to the fine grid is 10 mm-20 mm.

[0010] In a second aspect, the present application provides a photovoltaic cell comprising a plurality of fine grids printed on the front and m main grids intersecting therewith, wherein each main grid comprises a plurality of first welding pads arranged in a direction perpendicular to the fine grids, and every two first welding pads are connected by a main grid connecting line, and for each first welding pad, n second welding pads are arranged at intervals therefrom in a direction parallel to the fine grids, wherein n is greater than m.

[0011] In some embodiments, a middle position along the length of the fine gate is divided into a first region and a second region, wherein the first region and the second region are symmetrical to each other.

[0012] In some embodiments, m=2, and n=16.

[0013] In some embodiments, one of the two main gates is disposed at a middle position along the length of the thin gate in the first region, and the other is disposed at a middle position along the length of the thin gate in the second region.

[0014] In some embodiments, a distance between two adjacent first pads along a direction perpendicular to the fine grid is 10 mm-20 mm.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The present application provides a main grid plate and a photovoltaic cell, which includes a plurality of fine grids and m main grids intersecting therewith, wherein each main grid includes a plurality of first pads arranged in a vertical direction of the fine grids, each two first pads are connected by a main grid connection line, and each first pad is arranged in a spaced relationship between n second pads in a parallel direction of the fine grids, wherein n is greater than m. Based on the above method, the m main grids arranged by the main grid plate can meet the cost reduction requirements of battery preparation and the welding tension requirements of the components; and, because the main grid can gather the current generated between the fine grids when a reverse bias voltage is applied, and can play a role in preventing the grid from breaking, the fine grids can have good ohmic contact, thereby improving the electrical performance of the photovoltaic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0018] Figure 1 It is a schematic diagram of a traditional printing screen provided by the present application;

[0019] Figure 2 It is a schematic diagram of a main grid-free version provided by the present application;

[0020] Figure 3 is a schematic diagram of a laser induction process provided by the present application;

[0021] Figure 4 is a schematic diagram of another laser induction process provided by the present application;

[0022] Figure 5 It is a schematic diagram of a main grid plate provided by the present application;

[0023] Figure 6 It is a schematic diagram of a photovoltaic cell provided in this application. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0025] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0026] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0027] The traditional printing screen includes a number of fine grids and a number of main grids intersecting the fine grids. Figure 1 As shown, the printing screen includes a plurality of fine grids arranged horizontally (in the x direction) and five main grids arranged vertically (in the y direction). The spacing between adjacent main grids is consistent with the horizontal spacing between adjacent pads on the printing screen.

[0028] Another commonly used printing screen is a busbar-free screen, which is different from the traditional printing screen in that the busbar design is eliminated. Figure 2As shown, the main grid-free screen only includes a plurality of thin grids arranged horizontally, and no main grid is arranged between adjacent pads, thereby achieving the purpose of reducing battery consumption.

[0029] In the laser induction process, Figure 3 As shown in the figure, the battery made by traditional printing screen generally presses the probe to the edge main grid to apply reverse bias voltage. Since the edge main grid can make electrical connection between the connected fine grids, it can gather the current generated between the fine grids. For the battery made by the main grid-free screen, Figure 4 As shown in the figure, due to the limitation of laser induction process, the probe is usually pressed to its front edge to apply reverse bias voltage. However, since there is no electrical connection between the fine gates under this design, the current between the fine gates cannot be converged. Once the gate is broken, the corresponding fine gate will not be able to form a good current loop in laser induction (i.e. Figure 4 As a result, the fine gate fails to form a good ohmic contact during laser induction, affecting the electrical performance of the battery.

[0030] It can be seen that the existing printing screen cannot well take into account the cost reduction needs of photovoltaic cells and the purpose of improving their electrical performance.

[0031] Based on this, the purpose of the first aspect of the present application is to provide a main grid plate and a photovoltaic cell that can meet the cost reduction needs of battery preparation and also meet the component welding tension requirements; and, because the main grid can gather the current generated between the fine grids when a reverse bias voltage is applied, and can play a role in preventing the grid from breaking, the fine grids can produce good ohmic contact, thereby improving the electrical performance of the photovoltaic cell.

[0032] Figure 5 A schematic diagram of a main grid plate provided in this application. Figure 5 , the x direction is the direction parallel to the fine grid, and the y direction is the direction perpendicular to the fine grid. The main grid screen includes multiple fine grids 1 and m main grids 2. The m main grids 2 intersect with parts of the multiple fine grids 1. Each main grid 2 includes multiple first pads 21 and main grid connection lines 22. Among them, the multiple first pads 21 are arranged at intervals along the vertical direction of the fine grid, and the main grid connection line 22 is connected between every two first pads 21. Further, for each first pad 21, n second pads 3 are arranged at intervals therewith along the direction parallel to the fine grid, where n is greater than m.

[0033] Based on the above main grid screen, compared with the traditional printed screen, since part of the main grid is eliminated, it can meet the cost reduction requirements of battery preparation and the component welding tension requirements. In addition, compared with the screen without main grid, since the main grid can gather the current generated between the fine grids when the reverse bias voltage is applied, and can play a role in preventing the grid from breaking, the fine grids can have good ohmic contact, thereby improving the electrical performance of the photovoltaic cell.

[0034] Continue to refer Figure 5 In some embodiments, the main grid plate can be divided into a first region A and a second region B along the middle of the length of the fine grid 1, wherein the first region A and the second region B are symmetrical to each other. Therefore, the fine grid 1, the main grid 2 and the pad 3 respectively arranged in the first region A and the second region B are also symmetrical to each other, making the appearance of the main grid plate more beautiful.

[0035] Further, in some embodiments, the main grid plate can adopt a 18BB wiring design. Figure 5 , taking 18BB as an example, m can be 2, and n can be 16. That is, the main grid plate can include two main grids 2. The two main grids are respectively arranged in the first area A and the second area B. In some embodiments, one of the two main grids 2 is arranged in the middle position along the length of the thin grid in the first area A, and the other is arranged in the middle position along the length of the thin grid in the second area B, so that the positions of the two main grids 2 are symmetrical.

[0036] In addition to the first pads 21 on the two main grids 2, the number of the second pads 3 arranged in parallel with the fine grids is 16. Therefore, compared with the traditional printing screen, the design of 16 main grids is cancelled, thereby effectively reducing the slurry required for printing. On this basis, since the main grid 2 can match the reverse bias probe to realize the current loop and can increase the current transmission channel, it can better match the laser induced technology and realize ohmic contact.

[0037] In some embodiments, the distance between two adjacent first pads 21 along the vertical direction of the fine grid may be 10 mm-20 mm.

[0038] It is understandable that, in addition to the 18BB wiring design, the main grid screen may also adopt other wiring designs, such as the 30BB wiring design. Therefore, in a specific implementation, the number of main grids 2 and the spacing between adjacent second pads 3 along the direction parallel to the fine grid may be flexibly adjusted according to actual conditions, and there is no restriction on this.

[0039] Figure 6 A schematic diagram of a photovoltaic cell provided in this application. Figure 6 , the x direction is parallel to the fine grid, and the y direction is perpendicular to the fine grid. Figure 4The pattern corresponding to the main grid screen shown in the figure specifically includes a plurality of fine grids 4 and m main grids 5. The m main grids 5 intersect with parts of the plurality of fine grids 4. Each main grid 5 includes a plurality of first pads 51 and a main grid connection line 52. The plurality of first pads 51 are arranged at intervals in the vertical direction of the fine grids, and the main grid connection line 52 is connected between every two first pads 51. Furthermore, for each first pad 51, n second pads 6 are arranged at intervals in the direction parallel to the fine grids, where n is greater than m.

[0040] In some embodiments, the photovoltaic cell can be divided into a first region A' and a second region B' along the middle of the length of the fine grid 4, wherein the first region A' and the second region B' are symmetrical to each other. Therefore, the fine grid 4, the main grid 5 and the pad 6 respectively arranged in the first region A' and the second region B' are also symmetrical to each other, making the appearance of the photovoltaic cell more beautiful.

[0041] Further, in some embodiments, m may be 2, and n may be 16. That is, the photovoltaic cell may include two main grids 5. The two main grids are respectively arranged in the first region A' and the second region B'. In some embodiments, one of the two main grids 5 is arranged in the middle position along the length of the thin grid in the first region A', and the other is arranged in the middle position along the length of the thin grid in the second region B', so that the positions of the two main grids 5 are symmetrical.

[0042] In addition to the first pads 51 on the two main grids 5, the number of second pads 6 arranged parallel to the fine grids and spaced apart therefrom is 16. Therefore, compared with the battery made by the traditional printing screen, the design of 16 main grids is cancelled, thereby effectively reducing the slurry required for printing.

[0043] In the laser induction process, continue to refer to Figure 5 , the reverse bias voltage probe can be pressed onto the main grid 5 in the first area A', while the main grid 5 in the second area B' is used to increase the current transmission channel, thereby better realizing the current loop and generating good ohmic contact between the fine grids 4, thereby improving the electrical performance of the photovoltaic cell.

[0044] Likewise, in some embodiments, the distance between two adjacent first pads 21 along the vertical direction of the fine grid may be 10 mm-20 mm.

[0045] In a specific implementation, the number of main grids 5 and the spacing between adjacent second pads 6 in a direction parallel to the fine grids can be flexibly adjusted according to actual conditions, and there is no limitation on this.

[0046] It can be seen that the above-mentioned main grid plate and photovoltaic cell can meet the cost reduction requirements of battery preparation and also meet the welding tension requirements of the components; and because the main grid can gather the current generated between the fine grids when a reverse bias voltage is applied and can play a role in preventing the grid from breaking, the fine grids can produce good ohmic contact, thereby improving the electrical performance of the photovoltaic cell.

[0047] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0048] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0049] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0050] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0051] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A main grid screen, characterized in that: It includes multiple fine grids and m main grids intersecting therewith, wherein each main grid includes multiple first pads arranged along the vertical direction of the fine grid, and every two first pads are connected by a main grid connection line. For each first pad, n second pads are arranged in a spaced relationship with the first pad along the parallel direction of the fine grid, wherein n is greater than m.

2. The main grid plate according to claim 1, characterized in that: The middle position along the length of the fine gate is divided into a first region and a second region, wherein the first region and the second region are symmetrical to each other.

3. The main grid plate according to claim 2, characterized in that: m=2, and n=16.

4. The main grid plate according to claim 3, characterized in that: One of the two main gates is arranged at a middle position along the length of the thin gate in the first region, and the other is arranged at a middle position along the length of the thin gate in the second region.

5. The main grid plate according to claim 1, characterized in that: The distance between two adjacent first pads along the vertical direction of the fine grid is 10 mm-20 mm.

6. A photovoltaic cell, characterized in that: It includes a plurality of fine grids printed on the front and m main grids intersecting therewith, wherein each main grid includes a plurality of first pads arranged along the vertical direction of the fine grids, and every two first pads are connected by a main grid connection line. For each first pad, n second pads are arranged spaced apart from it along the parallel direction of the fine grids, wherein n is greater than m.

7. The photovoltaic cell according to claim 6, characterized in that: The middle position along the length of the fine gate is divided into a first region and a second region, wherein the first region and the second region are symmetrical to each other.

8. The photovoltaic cell according to claim 7, characterized in that: m=2, and n=16.

9. The photovoltaic cell according to claim 8, characterized in that: One of the two main gates is arranged at a middle position along the length of the thin gate in the first region, and the other is arranged at a middle position along the length of the thin gate in the second region.

10. The photovoltaic cell according to claim 6, characterized in that: The distance between two adjacent first pads along the vertical direction of the fine grid is 10 mm-20 mm.

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