阅读说明：本技术 一种回字型主栅辅助线mwt太阳能电池背面板 (MWT solar cell back panel with square-shaped main grid auxiliary line ) 是由 刘锐 李旭智 职森森 吴仕梁 路忠林 张凤鸣 于 2020-06-17 设计创作，主要内容包括：本发明公开一种回字型主栅辅助线MWT太阳能电池背面板,所述背面板采用回字主栅辅助线以及铝栅线的形式,将MWT太阳能电池的正极点相连通；所述背面板上设有主栅,所述主栅经过一排或一列正极点,所述主栅在经过两个端部的正极点时,是渐变式的形状；所述回字主栅辅助线的两个相对的顶点为相邻的正极点,另两个相对的顶点为负极点；所述背面板的边缘采用分枝状栅线结构。本发明字型主栅辅助线MWT太阳能电池背面板设计可有效解决该变化带来的风险,实现MWT电池成本降低,推动薄片化、大片化发展。(The invention discloses a MWT solar cell back panel with a square-shaped main grid auxiliary line, which is characterized in that the back panel adopts a square-shaped main grid auxiliary line and aluminum grid lines to communicate the positive electrode points of an MWT solar cell; the back panel is provided with a main grid, the main grid passes through a row or a column of positive poles, and the main grid is in a gradual change shape when passing through the positive poles at the two ends; two opposite vertexes of the square-shaped main grid auxiliary line are adjacent positive points, and the other two opposite vertexes are negative points; the edge of the back panel adopts a branched grid line structure. The MWT solar cell back panel with the auxiliary lines of the main grids in the shape of the Chinese character 'ji' can effectively solve risks caused by the change, realize the cost reduction of the MWT cell, and promote the development of flaking and large-scale production.)

1. A MWT solar cell back panel with a square-shaped main grid auxiliary line is characterized in that the back panel adopts a square-shaped main grid auxiliary line and an aluminum grid line mode to communicate positive electrode points of MWT solar cells;

the back panel is provided with a main grid, the main grid passes through a row or a column of positive poles, and the main grid is in a gradual change shape when passing through the positive poles at the two ends; two opposite vertexes of the square-letter main grid auxiliary line are adjacent positive points in the same column, and the other two opposite vertexes are negative points;

the edge of the back panel adopts a branched grid line structure.

2. The MWT solar cell back panel according to claim 1, wherein the positive poles are N x N matrix arrangement on the back panel, negative poles are distributed on two sides of the positive pole matrix, the negative poles are arranged at a position between two positive poles, and two ends of each row of negative poles are longer than the positive poles by a length of half positive pole pitch;

adopting a single row of continuous W-shaped main grid auxiliary lines between the anode point and the edge cathode point; and a single row of continuous W-shaped main grid auxiliary lines are also adopted between the edge negative electrode point and the edge of the back panel of the battery.

3. The MWT solar cell back surface plate according to claim 1, wherein a row of negative electrode points is distributed between every two rows of positive electrode points in the positive electrode point matrix.

4. The MWT solar cell back panel according to claim 1, wherein the main grid has a shape that is specifically:

the end parts of the two ends are thinnest, gradually thicken to cover the whole positive pole point when reaching the positive pole point positions of the two end parts, and gradually thin after passing through the positive pole points of the two end parts;

after reaching the middle position between the anode point at the end part and the adjacent anode point, the anode point is gradually thickened to cover the anode point adjacent to the anode point at the end part, and then the thickness is kept until reaching the middle position.

5. The MWT solar cell back surface plate according to claim 2, wherein a single row of continuous W-shaped main grid auxiliary lines is adopted between the positive electrode point and the edge negative electrode point;

the highest point of the continuous W-shaped main grid auxiliary line is positioned at a positive pole point, the lowest point of the continuous W-shaped main grid auxiliary line is positioned at a negative pole point, and the last time are finished between the adjacent positive pole points or the adjacent negative pole points;

a single row of continuous W-shaped main grid auxiliary lines are also adopted between the edge negative electrode point and the edge of the back panel of the battery;

the highest point of the continuous W-shaped main grid auxiliary line is located at the middle point of the adjacent edge negative pole point, the lowest point of the continuous W-shaped main grid auxiliary line is located at the edge of the battery back panel, and the continuous W-shaped main grid auxiliary lines are parallel to each other.

6. The MWT solar cell back panel according to claim 1, wherein horizontal thin aluminum grid lines are distributed on the back panel at equal intervals, the thin aluminum grid lines are in accordance with a conventional cell design, and the thin aluminum grid lines are in accordance with a screen printing direction.

7. The MWT solar cell back panel according to claim 1, wherein the square main grid auxiliary line width is 120um, the fine grid line width is 100um, the diameter of the edge cathode point is 360um, the thickness of the middle cathode point is increased to 200um, and the fine grid line width is 210 um.

Technical Field

The invention belongs to the technical field of photovoltaics, and particularly relates to an electric field design of a MWT solar cell back panel with a square-shaped main grid auxiliary line.

Background

With the development of the photovoltaic industry, cost reduction is more and more important, the battery plate becomes larger and thinner gradually, and the large-scale and thin-scale photovoltaic development trend gradually moves to the 'flat price internet-surfing' era; however, such changes inevitably increase the overall warping (bending) of the battery plate, increase the difficulty of battery manufacturing, and even bring negative benefits once the losses such as good efficiency and productivity are not well controlled.

The thickness of MWT single crystal (158 mm and 162 mm) which is realized in mass production at present is 160um, the thickness of polycrystal (162 mm) is 170um, the back electric field is designed by an all-aluminum back field, the warpage is generally 1.5-2.0mm, if the thickness of the battery piece is reduced (130-; in addition, due to the unique battery structure of the MWT, if the design is performed according to the back aluminum grid line (linear main grid line + aluminum grid line) of the conventional double-sided battery, the balance of the back current cannot be realized, and a large amount of battery power loss is caused. Therefore, in order to realize the thinning and mass production of MWT batteries, two problems need to be solved: 1. the warpage is reduced through the design of a back aluminum grid line; 2. the back main grid line is designed in an unconventional linear mode (auxiliary lines are added), so that the overall collection of the battery is balanced.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the MWT solar cell back panel with the square-shaped main grid auxiliary line, and the new back electric field, namely the design of the square-shaped main grid auxiliary line and the aluminum grid line, can effectively solve the risk caused by the change, realize the cost reduction of the MWT cell and promote the development of flaking and large sheet formation.

The invention relates to a MWT solar cell back panel with a square-shaped main grid auxiliary line, which adopts the form of the square-shaped main grid auxiliary line and an aluminum grid line to communicate the positive points of MWT solar cells;

the back panel is provided with a main grid, the main grid passes through a row or a column of positive poles, and the main grid is in a gradual change shape when passing through the positive poles at the two ends; two opposite vertexes of the square-letter main grid auxiliary line are adjacent positive points in the same column, and the other two opposite vertexes are negative points;

the edge of the back panel adopts a branched grid line structure.

Furthermore, the positive poles are arranged on the back panel in an N × N matrix, negative poles are distributed on two sides of the positive pole matrix, the negative poles are arranged between the two positive poles, and two ends of each row of negative poles are longer than the positive poles by half of the distance between the positive poles;

adopting a single row of continuous W-shaped main grid auxiliary lines between the anode point and the edge cathode point; and a single row of continuous W-shaped main grid auxiliary lines are also adopted between the edge negative electrode point and the edge of the back panel of the battery.

Furthermore, a row of negative electrode points is distributed between every two rows of positive electrode points in the positive electrode point matrix.

Furthermore, the shape of the main gate is specifically as follows:

the end parts of the two ends are thinnest, gradually thicken to cover the whole positive pole point when reaching the positive pole point positions of the two end parts, and gradually thin after passing through the positive pole points of the two end parts;

after reaching the middle position between the anode point at the end part and the adjacent anode point, the anode point is gradually thickened to cover the anode point adjacent to the anode point at the end part, and then the thickness is kept until reaching the middle position.

Furthermore, a single row of continuous W-shaped main grid auxiliary lines are adopted between the positive electrode point and the edge negative electrode point;

the highest point of the continuous W-shaped main grid auxiliary line is positioned at a positive pole point, the lowest point of the continuous W-shaped main grid auxiliary line is positioned at a negative pole point, and the last time are finished between the adjacent positive pole points or the adjacent negative pole points;

a single row of continuous W-shaped main grid auxiliary lines are also adopted between the edge negative electrode point and the edge of the back panel of the battery;

the highest point of the continuous W-shaped main grid auxiliary line is located at the middle point of the adjacent edge negative pole point, the lowest point of the continuous W-shaped main grid auxiliary line is located at the edge of the battery back panel, and the continuous W-shaped main grid auxiliary lines are parallel to each other.

Horizontal thin grid lines are distributed on the back panel at equal intervals, the thin grid lines are consistent with the design of a conventional battery, and the direction of the thin grid lines is consistent with the screen printing direction.

As a preferred choice of this scheme, return word main grid auxiliary line linewidth 120um, thin grid linewidth 100um, edge negative pole point diameter is 360um, and middle negative pole point adds thick to 200um, thin grid linewidth 210 um.

The technical scheme of the invention at least has the following beneficial effects:

1. the design can effectively reduce the warping of the battery piece, is more suitable for the production of thin and large battery pieces, and achieves the purposes of thinning the silicon wafer and reducing the cost;

2. the design can effectively reduce the consumption of the back surface field aluminum paste single sheet and reduce the cost of the back surface aluminum paste single sheet;

3. and opening a technical window designed by the MWT battery back aluminum grid line, and providing technical reserve for subsequent further flaking and large-scale formation.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the present invention will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without inventive labor.

Fig. 1 is a schematic view of the overall structure of a wrap-around main grid auxiliary line MWT solar cell back panel according to the present invention;

FIG. 2 is an enlarged view of a portion of the main gate of the present invention;

FIGS. 3 and 4 are enlarged partial views of the edge position main grid branches of the present invention;

FIG. 5 is a partial enlarged view of the fine grid location of the present invention;

FIG. 6 is a graph comparing results of performance tests on battery back panels in various configurations;

reference number designations in the drawings: 1-positive pole point, 2-negative pole point, 3-zigzag main grid auxiliary line, 4-main grid, 5-W-shaped main grid auxiliary line and 6-fine grid line.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 1, the present embodiment provides a loop-shaped main grid auxiliary line MWT solar cell back panel, which takes the form of a loop-shaped main grid auxiliary line 3 and an aluminum grid line, and connects the positive electrode point 1 of the MWT solar cell;

the back panel is provided with a main grid 4, the main grid 4 passes through a row or a column of positive poles 1, and the main grid 4 is in a gradual change shape when passing through the positive poles 1 at two ends; two opposite vertexes of the square-letter main grid auxiliary line 3 are adjacent positive electrode points 1, and the other two opposite vertexes are negative electrode points 2;

the edge of the back panel adopts a branched grid line structure.

As shown in fig. 1, the new back field (i.e., the square-shaped main gate auxiliary line 3+ the thin gate line 6 aluminum gate line) MWT design technical solution:

the back panel is provided with a main grid 4, the main grid 4 passes through a row or a column of positive poles 1, and the main grid 4 is in a gradual change shape when passing through the positive poles 1 at the two ends; two opposite vertexes of the square-letter main grid auxiliary line 3 are adjacent positive electrode points 1, and the other two opposite vertexes are negative electrode points 2; in this embodiment, the back surface is 5 × 5 arrangement electrode points (positive electrode point 1), and the back surface main grid 4 line passes through the single row electrode points (positive electrode point 1).

As a further introduction of this embodiment, as shown in fig. 2, each main grid 4 is of a gradual change design, so as to reduce the consumption of aluminum paste, the main grids are connected by auxiliary lines, the whole main grid is in a shape of a Chinese character 'hui', and the current is collected and guided to the electrode points; the shape of the main grid 4 is specifically as follows:

the end parts of the two ends are thinnest, gradually thicken to cover the whole positive pole 1 when reaching the positive pole 1 of the two end parts, and gradually thin after passing through the positive pole points 1 of the two end parts;

after reaching the middle position between the positive pole point 1 at the end part and the adjacent positive pole point 1, the thickness of the positive pole point 1 is gradually increased to cover the positive pole point 1 adjacent to the positive pole point 1 at the end part, and then the thickness is kept until reaching the middle position.

The design of the branched grid lines at the edges of the battery pieces (MWT characteristic, the edge area of the battery pieces is far away from the main grid 4) achieves the balance of integral current collection, and the power of the battery is ensured; a single row of continuous W-shaped main grid auxiliary lines 5 are adopted between the positive pole point 1 and the negative pole point 2; a single row of continuous W-shaped main grid auxiliary lines 5 is also used between the negative electrode point 2 and the edge of the cell back plane.

Further, in the matrix of the positive pole points 1, a row of negative pole points 2 is distributed between every two rows of positive pole points 1.