CRYSTALLINE SILICON SOLAR CELL SCREEN FOR POSITIVE ELECTRODE HOLLOW MOLDING

Abstract

Disclosed is a screen printing plate (5) for manufacturing a crystalline silicon solar cell, a positive electrode of the crystalline silicon solar cell comprising a positive electrode busbar (1), a positive electrode grid (2) and a break-proof grid structure (3), wherein the screen printing plate (5) is used at least for integrally printing and forming the positive electrode grid (2) and the break-proof grid structure (3). The screen printing plate (5) is provided with a blocking portion for blocking the passage of a paste, the blocking portion is a photosensitive emulsion (6) or a non-photosensitive emulsion, and the blocking portion corresponds to the break-proof grid structure (3) of the positive electrode and is used for forming a hollow-out groove (4) in the break-proof grid structure (3) when the positive electrode is printed. The blocking portion is positioned such that the hollow-out groove (4) is formed in a portion of the break-proof grid structure (3) between the positive electrode busbar (1) and the positive electrode grid (2).

Claims

1. A screen printing plate for manufacturing a crystalline silicon solar cell, a positive electrode of the crystalline silicon solar cell comprising a positive electrode busbar, a positive electrode grid and a break-proof grid structure, wherein the screen printing plate is at least used for integral printing forming of the positive electrode grid and the break-proof grid structure, wherein the screen printing plate is provided with a blocking portion for blocking the passage of a paste, the blocking portion corresponding to the break-proof grid structure of the positive electrode and being used for forming a hollow-out groove at a position in the break-proof grid structure corresponding to the blocking portion when the positive electrode is printed, and wherein the blocking portion is positioned such that the hollow-out groove is formed in a portion of the break-proof grid structure between the positive electrode busbar and the positive electrode grid.

2. The screen printing plate for manufacturing a crystalline silicon solar cell of claim 1, wherein the blocking portion is a photosensitive emulsion or non-photosensitive emulsion.

3. The screen printing plate for manufacturing a crystalline silicon solar cell of claim 1, wherein the screen printing plate comprises a break-proof grid forming region which allows a paste to pass therethrough to form the break-proof grid structure, wherein the break-proof grid forming region is an octagon comprising a rectangle located in the middle and two isosceles trapezoids that are located at both sides of the rectangle and are provided symmetrically with the rectangle as a center, the rectangle spans the positive electrode busbar and left and right ends of the rectangle extend out of the positive electrode busbar, the extended region is an extensional break-proof region of a rectangle shape, both ends of the isosceles trapezoid are respectively in contact with the extensional break-proof region and the positive electrode grid, the isosceles trapezoid is a tapered region with a cross section gradually reducing in a direction from the positive electrode busbar to the positive electrode grid, and the blocking portion is located within the isosceles trapezoid or spans the extensional break-proof region and the isosceles trapezoid.

4. The screen printing plate for manufacturing a crystalline silicon solar cell of claim 1, wherein the blocking portion is arranged in a lengthwise direction of the positive electrode grid.

5. The screen printing plate for manufacturing a crystalline silicon solar cell of claim 1, wherein the blocking portion is arranged in a direction perpendicular to a lengthwise direction of the positive electrode grid.

6. The screen printing plate for manufacturing a crystalline silicon solar cell of claim 1, wherein the blocking portion includes one or more blocking portions, so that one or more hollow-out grooves are formed in each break-proof grid structure.

7. The screen printing plate for manufacturing a crystalline silicon solar cell of claim 1, wherein the blocking portion is in a shape of a rectangle or circle.

8. The screen printing plate for manufacturing a crystalline silicon solar cell of claim 7, wherein a length and width of the rectangle is selected from a range of 0.034-0.084 mm; and a diameter of the circle is in a range of 0.034-0.084 mm.

9. The screen printing plate for manufacturing a crystalline silicon solar cell of claim 1, wherein a distance between a center of the blocking portion and an edge of the positive electrode busbar is in a range of 0.033-0.068 mm.

10. The screen printing plate for manufacturing a crystalline silicon solar cell of claim 3, wherein a width of a lower base of the isosceles trapezoid of the break-proof grid forming region is in a range of 0.050-0.500 mm, a width of an upper base of the isosceles trapezoid is the same as a width of the positive electrode grid, and a height of the isosceles trapezoid is in a range of 0.400-1.600 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present disclosure will be described in more detail hereinafter with reference to figures and specific embodiments.

[0017] FIG. 1 is a front view of a crystalline silicon solar cell manufactured with a screen printing plate according to the present disclosure;

[0018] FIG. 2 is a structural schematic view of a front side of the positive electrode of the crystalline silicon solar cell manufactured with the screen printing plate according to the present disclosure;

[0019] FIG. 3 is a structural schematic view of a rear side of the positive electrode of the crystalline silicon solar cell manufactured with the screen printing plate according to the present disclosure;

[0020] FIG. 4 is a structural schematic view of a rear side of a break-proof grid structure in the positive electrode of the crystalline silicon solar cell manufactured with the screen printing plate according to the present disclosure;

[0021] FIG. 5 is a structural schematic view of a front side of the screen printing plate according to the present disclosure;

[0022] FIG. 6 is a structural schematic view showing a change of height of a square hollow-out region in the positive electrode of the crystalline silicon solar cell manufactured with the screen printing plate according to the present disclosure before and after printing.

PARTS DENOTED BY REFERENCE NUMBERS

[0023] 1 positive electrode busbar, 2 positive electrode grid, 3 break-proof grid structure, 4 hollow-out groove, 5 screen printing plate, 6 photosensitive emulsion, 7 busbar region, 8 break-proof grid region without hollow-out groove superimposed, 9 break-proof grid region with hollow-out groove superimposed.

DETAILED DESCRIPTION

[0024] FIGS. 1-6A show a screen printing plate of a crystalline silicon solar cell for positive electrode hollow-out forming. The positive electrode of the crystalline silicon solar cell comprises a positive electrode busbar 1, a positive electrode grid 2, and a break-proof grid structure 3, wherein the break-proof grid structure 3 and the positive electrode grid 2 are integrally printed and formed; the printed break-proof grid structure 3 and the positive electrode grid 2 form a line, and are both perpendicular to the positive electrode busbar 1. The break-proof grid structure 3 is an octagon; the break-proof grid structure 3 comprises a rectangular grid segment located in the middle and two isosceles trapezoidal grid segments that are located at both sides of the rectangular grid segment and are provided symmetrically with the rectangular grid segment as a center. The isosceles trapezoidal grid segment is a tapered grid segment with a cross section gradually reducing in a direction from the positive electrode busbar 1 to the positive electrode grid 2.

[0025] To obtain the above positive electrode, the screen printing plate 5 comprises a break-proof grid forming region which allows a paste to pass therethrough to form the break-proof grid structure 3. To obtain the above break-proof grid structure 3, the break-proof grid forming region of the screen printing plate 5 is an octagon comprising a rectangle located in the middle and two isosceles trapezoids that are located at both sides of the rectangle and are provided symmetrically with the rectangle as a center. The rectangle spans the positive electrode busbar 1 and left and right ends of the rectangle extend out of the positive electrode busbar 1. The extended region is an extensional break-proof region of a rectangle shape. Both ends of the isosceles trapezoid are respectively in contact with the extensional break-proof region and the positive electrode grid 2. The isosceles trapezoid is a tapered region with a cross section gradually reducing in a direction from the positive electrode busbar 1 to the positive electrode grid 2.

[0026] In the present embodiment, in a non-limiting manner, a photosensitive emulsion 6 is disposed to protrude from a front side of the screen printing plate 5. The photosensitive emulsion 6 corresponds to the break-proof grid structure 3 of the positive electrode. When the positive electrode is printed, a hollow-out groove 4 is formed at a position of the back side of the break-proof grid structure 3 corresponding to the photosensitive emulsion 6, so as to reduce the probability of grid breakage when the positive electrode is printed. It is to be understood that the photosensitive emulsion 6 may also be disposed on the back side of the screen printing plate 5. Alternatively, a non-photosensitive emulsion or other blocking portions blocking the passage of the paste may be used to replace the photosensitive emulsion 6. In some embodiments, the blocking portion is located in the isosceles trapezoid or spans the extensional break-proof region and the isosceles trapezoid.

[0027] In some embodiments, the blocking portion includes one or more blocking portions, so that one or more hollow-out grooves 4 are formed on the back side of each break-proof grid structure 3. In some embodiments, there are a plurality of photosensitive emulsions 6 with the same structure. The plurality of photosensitive emulsions 6 may be arranged in a lengthwise direction of the positive electrode grid 2 or arranged in a direction perpendicular to the lengthwise direction of the positive electrode grid 2. By way of example and as shown in FIGS. 4 and 5, the number of photosensitive emulsions 6 is twice that of the break-proof grid structures 3, so that two hollow-out grooves 4 are formed on the back side of each break-proof grid structure 3, and are located on both sides of the positive electrode busbar 1. It is to be appreciated that each break-proof grid structure 3 may also include other numbers of hollow-out grooves 4.

[0028] As an example, the photosensitive emulsion 6 may be square with a length of the photosensitive emulsion 6 being 0.050 mm. The distance between the center of the photosensitive emulsion 6 and an edge of the positive electrode busbar 1 is 0.038 mm. Alternatively, the photosensitive emulsion 6 may have other shapes such as rectangle, a circle, an ellipse, and the like.

[0029] As a variation of the present embodiment, the length of the photosensitive emulsion 6 may also in a range of 0.034-0.084 mm, and the distance between the center of the photosensitive emulsion 6 and the edge of the positive electrode busbar 1 may be in a range of 0.033-0.068 mm. By way of example, when the photosensitive emulsion 6 is rectangular, the values of its length and width are selected from a range of 0.034-0.084 mm. In case that the photosensitive emulsion 6 is circular, its diameter is in a range of 0.034-0.084 mm.

[0030] In some embodiments, a width of a lower base of the isosceles trapezoid of the break-proof grid forming region is in a range of 0.050-0.500 mm, a width of an upper base of the isosceles trapezoid is the same as the width of the positive electrode grid 2, and a height of the isosceles trapezoid is in a range of 0.400-1.600 mm.

[0031] A principle of forming the hollow-out groove of the positive electrode manufactured with the screen printing plate of the present disclosure is as follows: when a screen printing plate is designed for the solar cell, a protruding square photosensitive emulsion is added at a position of the screen printing plate corresponding to the hollow-out groove of the break-proof grid structure, to make the break-proof grid structure hollow. When the positive electrode is printed in reality, the hollow-out groove 4 is formed on the back side of the break-proof grid structure 3.

[0032] When the screen printing plate of the present disclosure is used in the positive electrode hollow-out forming, the length of the hollow-out groove 4 formed on the back side of the break-proof grid structure 3 is in a range of 0.034-0.084 mm. The functional principle of the hollow-out groove 4 is shown in FIG. 6. When the scraper passes by the busbar region 7 upon printing, the printing height of the corresponding paste gradually reduces until the printing enters the break-proof grid region 8 of the non-superimposed hollow-out groove, and the printing height gradually increases; when the printing enters the break-proof grid region 9 of the superimposed hollow-out groove, the printing height rises rapidly, thereby further enhancing the break-proof grid effect.

[0033] Therefore, the screen printing plate of the present disclosure is provided with the photosensitive emulsion protruding from the front side. When the positive electrode is printed, the hollow-out groove is formed at a position where the back side of the break-proof grid structure corresponds to the photosensitive emulsion, so as to effectively reduce the probability of grid breakage when the front-side electrode is printed, to ensure that the grid line collects photo-generated carriers to a maximum extent, and to improve the efficiency of the cell. At the same time, since the cell with the broken grid is used to make a component, a hot spot effect of the component will be increased. By preventing the grid breakage, the present disclosure achieves a function of reducing the hot spot effect of local heating of the component and improves the service life of the component. The present disclosure is simple in structural design and has a wide scope of application.

[0034] The above-mentioned embodiments of the present disclosure are not intended to limit the scope of protection of the present disclosure, and the embodiments of the present disclosure are not limited thereto. Other various modifications, substitutes or variations to the above structures of the present disclosure according to the above content of the present disclosure as well as ordinary technical knowledge and customary means in the art without departing from the above basic technical ideas of the present disclosure should all fall within the protection scope of the present disclosure.