Screen printing plate, back contact photovoltaic module and photovoltaic system

Abstract

The utility model provides a printing screen, a back contact photovoltaic module and a photovoltaic system, relates to the technical field of photovoltaics, and can reduce the risk of short circuit of back contact battery pieces. The printing screen is used for printing insulation paste on the back contact battery piece, the printing screen comprises a plurality of first hollow-out areas and a plurality of second hollow-out areas, the first hollow-out areas extend in the first direction and are arranged in the second direction, the first hollow-out areas are located in the edge area of the printing screen in the second direction, and the second direction intersects with the first direction; the second hollowed-out areas are located in the non-edge area of the printing screen plate, extend in the first direction and are arranged in the second direction. The width of the first hollow-out area is larger than that of the second hollow-out area.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a printing screen, a back contact photovoltaic module and a photovoltaic system. BACKGROUND

[0002] A back contact cell is a photovoltaic cell with positive and negative grid lines distributed on the back surface. In some cases, a plurality of back contact cells need to be connected in series by welding ribbons. For a back contact cell, the positive and negative grid lines on the back contact cell need to be welded to different welding ribbons.

[0003] In order to avoid the welding ribbons and the grid lines of different polarities from being short-circuited (for example, the welding ribbons that need to be connected to the positive grid lines are short-circuited with the negative grid lines, or the welding ribbons that need to be connected to the negative grid lines are short-circuited with the positive grid lines), it is necessary to print insulating glue on the back surface of the back contact cell by using a printing screen.

[0004] In some cases, during the process of printing insulating glue on the back surface of the back contact cell by using the printing screen, the insulating glue at the edge of the back surface of the back contact cell cannot cover the grid lines, thereby increasing the risk of short-circuit of the back contact cell. CONTENT OF THE UTILITY MODEL

[0005] The present application provides a printing screen, a back contact photovoltaic module and a photovoltaic system, which can reduce the risk of short-circuit of the back contact cell.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, a printing screen is provided, which is used for printing insulating glue on a back contact cell. The printing screen comprises a plurality of first hollow areas and a plurality of second hollow areas. The first hollow areas extend along a first direction and are arranged along a second direction. The first hollow areas are located in an edge region of the printing screen in the second direction, and the second direction intersects the first direction. The second hollow areas are located in a non-edge region of the printing screen in the second direction, and extend along the first direction and are arranged along the second direction. The width of the first hollow areas along the second direction is greater than the width of the second hollow areas.

[0008] Based on the printing screen, since the width of the first hollow areas located in the edge region of the printing screen in the second direction is greater than the width of the second hollow areas located in the non-edge region of the printing screen, when the printing screen is subjected to a pulling force in the first direction intersecting the second direction, the width of the first hollow areas will not be less than the width of the second hollow areas. It can be ensured that the width of the insulating glue printed on the back contact cell is wide enough, so that the insulating glue at the edge of the back surface of the back contact cell can also cover the grid lines, thereby reducing the risk of short-circuit of the back contact cell.

[0009] With reference to the first aspect, in some embodiments of the first aspect, the printing screen plate comprises a first edge parallel to the first direction, and the plurality of first hollowed-out areas gradually widen in the edge region width along the second direction in the direction close to the first edge.

[0010] According to the scheme, since the plurality of first hollowed-out areas gradually widen in the direction close to the first edge parallel to the first direction, on the one hand, the closer to the first edge, the greater the deformation of the first hollowed-out area, and by making the first hollowed-out area wider, the width of the insulating glue printed on the back contact battery piece can be ensured to be wide enough, reducing the risk of short circuit of the back contact battery piece, on the other hand, when printing the insulating glue on the back contact battery piece, the amount of insulating glue can also be reduced, reducing the cost.

[0011] With reference to the first aspect, in some embodiments of the first aspect, the printing screen plate further comprises a first shielding portion, the first shielding portion extends along the second direction, and the first shielding portion corresponds to the tab connecting area of the back contact battery piece.

[0012] According to the scheme, since the tab has a certain height, the insulating glue also has a certain height, by setting the first shielding portion corresponding to the tab connecting area of the back contact battery on the printing screen plate, when printing the insulating glue on the back contact battery piece based on the printing screen plate, a containing portion that can accommodate the tab can be formed in the tab connecting area of the back contact battery piece, and after the tab connecting area of the back contact battery piece is connected to the tab, the height of the tab protruding from the insulating glue layer can be reduced, thereby reducing the risk of hidden cracking of the back contact battery piece.

[0013] With reference to the first aspect, in some embodiments of the first aspect, the printing screen plate further comprises a second shielding portion, the second shielding portion corresponds to the tab welding area of the back contact battery piece, and the length of the second shielding portion along the first direction is greater than the length of the tab welding area.

[0014] According to the scheme, by setting the second shielding portion corresponding to the tab welding area of the back contact battery piece on the printing screen plate, since the length of the second shielding portion along the first direction is greater than the length of the tab welding area, after printing the insulating glue on the back contact battery piece through the printing screen plate, the tab welding area and the tab can be fully welded in the first direction, thereby improving the effectiveness of welding the tab.

[0015] With reference to the first aspect, in some embodiments of the first aspect, the printing screen plate further comprises a third hollowed-out area and a fourth hollowed-out area connected in series, the extension directions of the third hollowed-out area and the fourth hollowed-out area are parallel to the first direction, the width of the third hollowed-out area is greater than the width of the fourth hollowed-out area, and the third hollowed-out area corresponds to the tab connecting area of the back contact battery piece.

[0016] Based on the scheme, in the case that the printing screen also includes a third hollow area and a fourth hollow area connected thereto, since the width of the third hollow area is greater than the width of the fourth hollow area, the third hollow area corresponds to the bonding ribbon connecting area of the back contact battery piece, after printing the insulating glue on the back contact battery piece based on the printing screen, the insulation between the bonding ribbon and the heterogeneous grid lines of the back contact battery piece can be improved, and the risk of short circuit of the back contact battery piece is further reduced.

[0017] In combination with the first aspect, in some embodiments of the first aspect, the fourth hollow area includes a first end and a second end, the first end is connected to the third hollow area, and the width of the first end along the second direction is greater than the width of the second end along the second direction.

[0018] Based on the scheme, since the first end of the fourth hollow area is connected to the third hollow area, the third hollow area corresponds to the bonding ribbon connecting area of the back contact battery piece, therefore, the farther away from the first end in the position of the back contact battery piece corresponding to the fourth hollow area, the less the insulating glue is needed, by making the width of the first end greater than the width of the second end, the amount of insulating glue can be reduced, and the cost is reduced.

[0019] In combination with the first aspect, in some embodiments of the first aspect, the printing screen also includes a fifth hollow area, and the fifth hollow area is used for printing the battery piece identification of the back contact battery piece.

[0020] Based on the scheme, since the printing screen also includes the fifth hollow area used for printing the battery piece identification of the back contact battery piece, the battery piece identification can be printed on the back contact battery piece, so as to improve the convenience of subsequent processing procedures of the back contact battery piece.

[0021] The second aspect provides a back contact photovoltaic module, the back contact photovoltaic module includes at least one back contact battery piece, and the back surface of the back contact battery piece is provided with insulating glue, and the insulating glue is printed by the printing screen provided in the first aspect and any possible embodiment thereof.

[0022] The third aspect provides a photovoltaic system, including the back contact photovoltaic module provided in the second aspect. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A partial structure schematic view of a printing screen is provided in the present application;

[0024] Figure 2 A partial structure schematic view of another printing screen is provided in the present application. DETAILED DESCRIPTION

[0025] In the description of the present application, "a plurality of" means two or more than two, unless otherwise specified. "At least one of the following" or similar expressions means any combination of the items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0026] In addition, in order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, "first", "second" and the like are used to distinguish the same items or similar items with basically the same function and role. Those skilled in the art can understand that "first", "second" and the like do not limit the quantity and execution order, and "first", "second" and the like do not necessarily mean different.

[0027] Meanwhile, in the embodiments of the present application, the words such as "exemplary" or "for example" are used to represent as an example, illustration or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. In fact, the words such as "exemplary" or "for example" are intended to present the relevant concept in a specific way, for understanding.

[0028] It can be understood that the "embodiments" mentioned throughout the specification mean that the specific features, structures or characteristics related to the embodiments are included in at least one embodiment of the present application. Therefore, the various embodiments throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It can be understood that in various embodiments of the present application, the size of the sequence number of each process does not mean the execution order, and the execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0029] It can be understood that in the present application, "when", "if" and "if" all refer to the corresponding processing under certain objective circumstances, not limited to time, and do not require a judgment action when implemented, nor does it mean that there are other limitations.

[0030] It can be understood that some optional features in the embodiments of the present application can be implemented independently in some scenarios, without relying on other features, such as the scheme currently based on, to solve the corresponding technical problems and achieve the corresponding effects. In some scenarios, it can also be combined with other features according to demand. Correspondingly, the devices given in the embodiments of the present application can also realize these features or functions, which will not be described here.

[0031] In the present application, the same or similar parts among various embodiments can be mutually referred to, unless otherwise specified. In the various embodiments in the present application, and the various implementation methods in the various embodiments, the terms and / or descriptions among different embodiments, and the various implementation methods in the various embodiments are consistent, and can be mutually referred to, unless otherwise specified and in conflict with logic, and the technical features in different embodiments, and the various implementation methods in the various embodiments can be combined to form new embodiments, implementation manners, implementation methods, or implementation methods according to their inherent logical relationship. The following implementation manners of the present application do not constitute a limitation on the protection scope of the present application.

[0032] The back contact cell is a cell with positive and negative grid lines distributed on the back surface of the cell. In some cases, a plurality of back contact cells need to be connected in series by welding ribbons. For a back contact cell, the positive and negative fine grid lines on the back contact cell need to be welded with different welding ribbons.

[0033] In order to avoid the welding ribbons from being short-circuited with the opposite grid lines (for example, the welding ribbons that need to be connected with the positive grid lines are short-circuited with the negative grid lines, or the welding ribbons that need to be connected with the negative grid lines are short-circuited with the positive grid lines), it is necessary to print insulating glue on the back surface of the back contact cell by printing a screen.

[0034] In some cases, for example, during the process of printing the insulating glue by the screen, the edge of the screen receives a greater pulling force than the non-edge of the screen, and the screen hole of the edge of the screen is deformed excessively, the width of the screen hole of the edge of the screen is narrowed in the direction perpendicular to the pulling force direction, resulting in that the width of the insulating glue printed on the cell is narrow, and the insulating glue on the edge of the back surface of the back contact cell cannot shield the grid lines, thereby resulting in a greater risk of short circuit of the back contact cell.

[0035] To solve the above problems, the utility model provides a kind of printing screen, printing screen is used to print insulating glue on back contact cell, Figure 1 The structure schematic diagram of the partial printing screen provided by the present application is shown as Figure 1 As shown, the printing screen 10 includes a plurality of first screen holes 20 and a plurality of second screen holes 30.

[0036] The first screen holes 20 extend along a first direction and are arranged along a second direction, the first screen holes 20 are located at the edge region of the printing screen 10 in the second direction, and the second direction intersects the first direction; the second screen holes 30 are located at the non-edge region of the printing screen 10 in the second direction, the second screen holes 30 extend along the first direction and are arranged along the second direction; the width of the first screen holes 20 along the second direction is greater than the width of the second screen holes 30.

[0037] The second direction can be perpendicular to the first direction.

[0038] The number of the first hollowed-out areas 20 or the second hollowed-out areas 30 can be 2, 3, 4, 5, of course, the number of the first hollowed-out areas 20 or the second hollowed-out areas 30 can also be other numbers, and the utility model does not make specific limitation to this.

[0039] The shape of the first hollowed-out area 20 or the second hollowed-out area 30 can be a regular figure, for example, a rectangle, a trapezoid or an ellipse, or the shape of the first hollowed-out area 20 or the second hollowed-out area 30 can also be an irregular figure, and the utility model does not make specific limitation to this.

[0040] The width of the first hollowed-out area 20 or the second hollowed-out area 30 refers to the minimum width of the first hollowed-out area 20 or the second hollowed-out area 30 in the second direction. For example, if the first hollowed-out area 20 or the second hollowed-out area 30 is a rectangle, the width of the first hollowed-out area 20 or the second hollowed-out area 30 is the width of the rectangle, and if the first hollowed-out area 20 or the second hollowed-out area 30 is an ellipse, the width of the first hollowed-out area 20 or the second hollowed-out area 30 is the width of the narrowest part of the first hollowed-out area 20 or the second hollowed-out area 30 in the second direction.

[0041] Taking the shape of the first hollowed-out area 20 or the second hollowed-out area 30 as a rectangle as an example, as shown in the figure, Figure 1 The number of the plurality of first hollowed-out areas 20 is 2 and the number of the plurality of second hollowed-out areas 30 is 2, the width of the plurality of first hollowed-out areas 20 is d1 and d2 respectively, the width of the plurality of second hollowed-out areas 30 is d3, and d1 and d2 are both greater than d3.

[0042] Based on the printing screen 10, since the width of the first hollowed-out area 20 located in the edge area of the printing screen 10 in the second direction is greater than the width of the second hollowed-out area 30 located in the non-edge area of the printing screen 10, when the printing screen 10 is subjected to the pulling force in the first direction intersecting the second direction, the width of the first hollowed-out area 20 will not be less than the width of the second hollowed-out area 30, which can ensure that the width of the insulating glue printed on the back contact battery piece is wide enough, so that the insulating glue at the edge of the back of the back contact battery piece can also shield the grid lines, reducing the risk of short circuit of the back contact battery piece.

[0043] In one design, the printing screen 10 includes a first edge 40 parallel to the first direction, and the edge area width of the plurality of first hollowed-out areas 20 in the second direction gradually widens along the direction close to the first edge 40.

[0044] As shown in the figure, Figure 1 d1 is greater than d2.

[0045] Based on the design, since the widths of the plurality of first hollowed-out areas 20 are sequentially widened along the direction close to the first edge 40 parallel to the first direction, on the one hand, the closer to the first edge 40, the greater the deformation of the first hollowed-out area 20, by making the width of the first hollowed-out area 20 wider, the width of the insulating glue printed on the back contact battery piece can be ensured to be wide enough, reducing the risk of short circuit of the back contact battery piece, on the other hand, when printing the insulating glue on the back contact battery piece, the amount of insulating glue can also be reduced, reducing the cost.

[0046] In one design, as shown in Figure 1 The printing screen 10 further comprises a first shielding portion 50, the first shielding portion 50 extends along the second direction, and the first shielding portion 50 corresponds to the tab connecting area of the back contact battery piece.

[0047] The width of the first shielding portion 50 can be greater than or equal to the width of the tab.

[0048] The number of the first shielding portion 50 is twice the number of the tabs of the back contact battery piece, and the positions (i.e. the tab connecting areas) of the back contact battery piece corresponding to the first shielding portion 50 are used to bond and fix the end portions of the tabs. That is, the tab connecting area of the back contact battery piece is an area on the back contact battery piece for bonding and fixing the end portions of the tabs on the back contact battery piece, so as to subsequently weld the tabs on the welding area of the back contact battery piece.

[0049] Based on the design, since the tabs have a certain height, the insulating glue also has a certain height, by setting the first shielding portion 50 corresponding to the tab connecting area of the back contact battery on the printing screen 10, when printing the insulating glue on the back contact battery piece based on the printing screen 10, an accommodating portion that can accommodate the tab can be formed in the tab connecting area of the back contact battery piece, after connecting the tab in the tab connecting area of the back contact battery piece, the height of the tab protruding from the insulating glue layer can be reduced, thereby reducing the risk of hidden cracking of the back contact battery piece.

[0050] In one design, as shown in Figure 1 The printing screen 10 further comprises a second shielding portion 60, the second shielding portion 60 corresponds to the welding area of the back contact battery piece, and the length of the second shielding portion 60 along the first direction is greater than the length of the welding area.

[0051] The welding area of the back contact battery piece refers to the area on the back contact battery piece for welding the tab.

[0052] The second shielding portion 60 corresponds to the first shielding portion 50 one by one, that is, the number of the second shielding portion 60 is the same as the number of the first shielding portion 50.

[0053] Based on this design, by setting a second shielding part 60 corresponding to the welding area of ​​the back contact cell in the printing screen 10, since the length of the second shielding part 60 in the first direction is greater than the length of the welding area, after the insulating adhesive is printed onto the back contact cell by the printing screen 10, the welding area and the solder strip can be fully welded in the first direction, thereby improving the effectiveness of welding the solder strip.

[0054] In a design, such as Figure 1 As shown, the printing screen 10 also includes a third cutout area 70 and a fourth cutout area 80 connected to each other. The extension directions of the third cutout area 70 and the fourth cutout area 80 are parallel to the first direction. The width of the third cutout area 70 is greater than the width of the fourth cutout area 80. The position of the third cutout area 70 on the back contact cell corresponding to the third cutout area 70 is used to connect the solder strip.

[0055] The shape of the third hollow area 70 or the fourth hollow area 80 can be a regular shape, such as a rectangle, trapezoid, or ellipse. Alternatively, the shape of the third hollow area 70 or the fourth hollow area 80 can also be an irregular shape. This utility model does not impose specific limitations on this.

[0056] The width of the third cutout area 70 refers to the minimum width of the third cutout area 70 in the second direction.

[0057] The width of the fourth cutout area 80 refers to the maximum width of the fourth cutout area 70 in the second direction.

[0058] Based on this design, when the printing screen 10 also includes a connected third cutout area 70 and a fourth cutout area 80, since the width of the third cutout area 70 is greater than the width of the fourth cutout area 80, and the third cutout area 70 corresponds to the solder ribbon connection area of ​​the back contact cell, after printing insulating adhesive onto the back contact cell based on the printing screen 10, the insulation between the solder ribbon and the irregular grid lines of the back contact cell can be improved, further reducing the risk of short circuit of the back contact cell.

[0059] In one design, the fourth cutout area 80 includes a first end 801 and a second end 802. The first end 801 is connected to the third cutout area 70, and the width of the first end 801 along the second direction is greater than the width of the second end 802 along the second direction.

[0060] Figure 2 A partial structural schematic diagram of another printing screen provided in this application, such as... Figure 2 As shown, the width d4 of the first end 801 of the fourth hollow area 80 is greater than the width d5 ​​of the second end 802 of the fourth hollow area 80.

[0061] The width of the fourth hollow area 80 can be narrowed in a stepped manner from the first end 801 to the second end 802, or, as... Figure 2As shown, the width of the fourth hollow area 80 can be tapered from the first end 801 to the second end 802, and the utility model does not make specific limitation to this.

[0062] Based on the design, since the first end 801 of the fourth hollow area 80 is connected with the third hollow area 70, and the third hollow area 70 corresponds to the solder strip connecting area of the back contact battery piece, therefore, in the position of the back contact battery piece corresponding to the fourth hollow area 80, the farther away from the first end 801, the smaller the demand for insulating glue, by making the width of the first end 801 greater than the width of the second end 802, the amount of insulating glue can be reduced, and the cost is reduced.

[0063] In one design, as shown in the figure, Figure 1 The printing screen 10 further comprises a fifth hollow area 90, and the fifth hollow area 90 is used for printing the identification of the back contact battery piece.

[0064] The fifth hollow area 90 can be various patterns, for example, a wave shape, or, as shown in the figure, Figure 1 The fifth hollow area 90 can also be a cross shape, and the utility model does not make specific limitation to this.

[0065] The shape of the fifth hollow area 90 is different from the shape of other hollow areas.

[0066] In the case that the back contact battery piece does not need to be segmented subsequently, the fifth hollow area 90 can be located in any area of the printing screen 10, and in the case that the back contact battery piece needs to be segmented subsequently, the fifth hollow area 90 can be located in the area corresponding to any half battery piece on the printing screen 10.

[0067] The battery piece identification can identify the battery piece in the subsequent processing procedure of the back contact battery piece.

[0068] Based on the design, since the printing screen 10 further comprises the fifth hollow area 90 used for printing the battery piece identification of the back contact battery piece, the battery piece identification can be printed on the back contact battery piece, so as to improve the convenience of the subsequent processing procedure of the back contact battery piece.

[0069] In one design, as shown in the figure, Figure 1 The printing screen 10 further comprises a sixth hollow area 100, and the sixth hollow area 100 is used for printing the positioning identification of the back contact battery piece.

[0070] The shape of the sixth hollow area 100 can be various shapes, for example, an elliptical shape, a triangular shape, or, as shown in the figure, Figure 1 The shape of the sixth hollow area 100 can also be a circular shape, and the utility model does not make specific limitation to this.

[0071] The shape of the sixth hollow area 100 is different from the shape of other hollow areas.

[0072] Based on the design, since the printing screen 10 further comprises the sixth hollow area 100 for printing the positioning mark of the back contact battery piece, the positioning mark can be printed on the back contact battery piece to improve the accuracy of positioning the back contact battery piece in the subsequent processing procedure of the back contact battery piece.

[0073] In one design, as shown in Figure 1 or Figure 2 The projections of the two fourth hollow areas 80 corresponding to different polarity grid lines of the back contact battery piece in the second direction overlap.

[0074] Based on the design, since the projections of the two fourth hollow areas 80 corresponding to different polarity grid lines of the back contact battery piece in the second direction overlap, when printing the insulating glue on the back contact battery piece by the printing screen 10, the length of the insulating glue can be increased, and the risk of short circuit of the back contact battery piece can be further reduced.

[0075] The utility model embodiment provides a back contact photovoltaic module, back contact photovoltaic module includes at least one back contact battery piece, the back surface of back contact battery piece is provided with insulating glue, and the insulating glue is printed by the printing screen 10.

[0076] It can be understood that the photovoltaic module can further include a metal frame, a back plate, photovoltaic glass and a film. The film can be filled between the front and back surfaces of the photovoltaic module, photovoltaic glass, adjacent back contact photovoltaic modules, etc., and can be a transparent gel with good light transmission and aging resistance, for example, the film can use EVA film or POE film, which can be selected according to actual conditions, and is not limited herein.

[0077] The photovoltaic glass can be covered on the film on the front surface of the back contact photovoltaic module. The photovoltaic glass can be super white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of the super white glass can be more than 92%, which can protect the back contact photovoltaic module as much as possible without affecting the efficiency of the back contact photovoltaic module. At the same time, the film can bond the photovoltaic glass and the back contact photovoltaic module together, and the presence of the film can seal and insulate the back contact photovoltaic module and prevent water and moisture.

[0078] The back plate can be attached to the adhesive film on the back of the back contact photovoltaic module. The back plate can protect and support the back contact photovoltaic module, has reliable insulation, water resistance and aging resistance, and the back plate can have multiple choices, which can be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. The specific setting can be made according to the specific situation, which is not limited here. The whole composed of the back plate, the back contact photovoltaic module, the adhesive film and the photovoltaic glass can be arranged on the metal frame. The metal frame serves as the main external supporting structure of the whole photovoltaic module, and can stably support and install the photovoltaic module. For example, the photovoltaic module can be installed at the required installation position through the metal frame.

[0079] The utility model embodiment provides a photovoltaic system, comprising the back contact photovoltaic module described above.

[0080] In the embodiment, the photovoltaic system can be applied in photovoltaic power stations, such as ground power stations, roof power stations, water surface power stations, etc., and can also be applied in devices or apparatuses that generate electricity by using solar energy, such as user solar power sources, solar street lamps, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be applied in all fields that need to generate electricity by using solar energy. Taking a photovoltaic power generation system network as an example, the photovoltaic system can include a photovoltaic array, a current combiner box and an inverter. The photovoltaic array can be an array combination of multiple cell modules. For example, multiple cell modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the current combiner box. The current combiner box can combine the current generated by the photovoltaic array. After the combined current flows through the inverter to convert into alternating current required by the power grid, the alternating current is connected to the power network to realize solar power supply.

[0081] Although the utility model is described herein in combination with various embodiments, during the implementation of the claimed utility model, other changes of the disclosed embodiments can be understood and implemented by those skilled in the art by viewing the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "a" does not exclude multiple cases. A single processor or other unit can implement several functions listed in the claims. Some measures are recorded in mutually different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0082] Although the present application is described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations are possible in the spirit and scope of the present application. Accordingly, the description and drawings are to be regarded simply as illustrative in nature and are not to be regarded as limiting in any way. Obviously, various modifications and changes can be made to the present application by those skilled in the art without departing from the spirit and scope of the present application. Therefore, it is intended that the present application encompass all such modifications and changes and, accordingly, the above description is to be construed as illustrative only.

Claims

1. A printing screen, characterized in that The printing screen is used for printing insulating glue on a back contact cell, and comprises a plurality of first hollowed-out areas and a plurality of second hollowed-out areas, the first hollowed-out areas extend along a first direction and are arranged along a second direction, the first hollowed-out areas are located in an edge region of the printing screen in the second direction, and the second direction intersects the first direction; the second hollowed-out areas are located in a non-edge region of the printing screen in the second direction, the second hollowed-out areas extend along the first direction and are arranged along the second direction; and a width of the first hollowed-out areas along the second direction is greater than a width of the second hollowed-out areas.

2. The printing screen according to claim 1, characterized in that The printing screen comprises a first edge parallel to the first direction, and a plurality of the first hollowed-out areas are sequentially widened in an edge region width along the second direction in a direction close to the first edge.

3. The printing screen according to claim 1, characterized in that The printing screen further comprises a first shielding part, the first shielding part extends along the second direction, and the first shielding part corresponds to a tab connection region of the back contact cell.

4. The printing screen according to claim 1, characterized in that The printing screen further comprises a second shielding part, the second shielding part corresponds to a tab connection region of the back contact cell, and a length of the second shielding part along the first direction is greater than a length of the tab connection region.

5. The printing screen according to claim 4, characterized in that The printing screen further comprises a third hollowed-out area and a fourth hollowed-out area connected in sequence, the third hollowed-out area and the fourth hollowed-out area extend along the first direction, a width of the third hollowed-out area along the second direction is greater than a width of the fourth hollowed-out area, and the third hollowed-out area corresponds to a tab connection region of the back contact photovoltaic module.

6. The printing screen according to claim 5, characterized in that The fourth hollowed-out area comprises a first end and a second end, the first end is connected with the third hollowed-out area, and a width of the first end along the second direction is greater than a width of the second end along the second direction.

7. The printing screen according to any one of claims 1 to 6, characterized in that The printing screen further comprises a fifth hollowed-out area, and the fifth hollowed-out area is used for printing an identification of the back contact cell.

8. A back contact photovoltaic module characterized by, The back contact photovoltaic module comprises at least one back contact cell, a back surface of the back contact cell is provided with insulating glue, and the insulating glue is printed by the printing screen according to any one of claims 1 to 7.

9. A photovoltaic system characterized by, The battery module comprises the battery module according to claim 8.

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