阅读说明：本技术 一种太阳能电池导电电极线的分布和制造方法 (Distribution and manufacturing method of solar cell conductive electrode wires ) 是由 上管泉元 贾云涛 于 2020-04-29 设计创作，主要内容包括：本发明公开了一种太阳能电池导电电极线的分布方法,包括主栅线和细栅线并分别印刷；单根细栅线在长度方向上间断式分割为多段细栅主体,间断处通过主栅导通连接；单根主栅线在长度方向上间断式分割为多段主栅主体,每段主栅主体用于导通同一根细栅线的相邻两段细栅主体；相邻平行的细栅线之间通过连接线导通连接,采用钢箔、PI膜或PET膜等硬质薄材制作对应结构的细栅网版以用于上述细栅线分布结构的导电电极的印刷制作。本发明可以把细栅线宽度做到30μm以下且虚印、断栅现象少,从而降低电阻并提升电池效率,减少银浆使用量以降低制作成本,尤其适用于需要双面印刷且使用昂贵低温银浆的HIT电池的制作,且钢箔、PI膜或PET膜网版的成本低、使用寿命长。(The invention discloses a distribution method of a solar cell conductive electrode wire, which comprises a main grid line and a fine grid line which are respectively printed; a single thin grid line is intermittently divided into a plurality of sections of thin grid main bodies in the length direction, and the intermittent parts are connected through the main grid in a conduction way; the single main grid line is intermittently divided into a plurality of sections of main grid main bodies in the length direction, and each section of main grid main body is used for conducting two adjacent sections of fine grid main bodies of the same fine grid line; the adjacent parallel thin grid lines are connected through connecting lines, and hard thin materials such as steel foils, PI films or PET films are adopted to manufacture thin grid screen printing plates with corresponding structures for printing and manufacturing the conductive electrodes of the thin grid line distribution structure. The invention can make the width of the thin grid line less than 30 μm and has less phenomena of virtual printing and grid breaking, thereby reducing the resistance and improving the battery efficiency, reducing the use amount of silver paste to reduce the manufacturing cost, being particularly suitable for manufacturing HIT batteries which need double-sided printing and use expensive low-temperature silver paste, and having low cost and long service life of steel foil, PI film or PET film screen printing plates.)

1. A distribution method of a solar cell conductive electrode wire is characterized by comprising a main grid line and a fine grid line which are respectively printed on the surface of a cell; the single thin grid line comprises a plurality of sections of thin grid main bodies which are distributed discontinuously in the length direction, and the thin grid main bodies which are discontinuous on two sides of the main grid line are connected in a conducting mode through the main grid line printed at the discontinuous part between the two adjacent sections of thin grid main bodies.

2. The method as claimed in claim 1, wherein the single main grid line includes a plurality of main grid bodies intermittently distributed in a length direction, each main grid body is configured to conduct two adjacent sections of the same thin grid line, and two adjacent parallel thin grid lines are conductively connected by a connection line.

3. A method for manufacturing a conductive electrode wire of a solar cell according to claim 1 or 2, comprising the following steps:

(1) manufacturing a fine grid screen printing plate: firstly, a hard thin material is tensioned and fixed on a net frame in a net stretching mode; etching a fine grid pattern on the hard thin material, and segmenting the middle of a single fine grid pattern to form a plurality of segments of intermittently distributed fine grid main body meshes, wherein the number of the segments corresponds to the number and the positions of the main grid lines, namely M main grid lines need to correspond to M +1 segments of fine grid main body meshes;

(2) manufacturing a main grid screen printing plate;

(3) printing the fine grid line silver paste on the front surface of the cell by adopting the fine grid screen printing plate manufactured in the step (1) to form a discontinuous distribution fine grid main body;

(4) drying the discontinuous fine grid main body formed by printing in the step (3);

(5) printing corresponding main grid line silver paste on the front surface of the battery piece by adopting the main grid screen plate manufactured in the step (2) to form main grid lines which are connected in a conduction mode through the fine grid main bodies distributed discontinuously;

(6) drying the main grid line formed in the step (5);

(7) and (4) curing the main grid line and the fine grid main body after drying in the step (4) and the step (6).

4. The manufacturing method of the conductive electrode wire of the solar cell according to claim 3, characterized in that (3) - (6) are repeated, the fine grid main body and the main grid lines are sequentially printed on the back surface of the cell piece, and then the curing treatment is carried out together with the fine grid main body and the main grid lines printed on the front surface of the cell piece.

5. The method for manufacturing the conductive electrode wire of the solar cell according to claim 3, wherein (2) the main grid screen is manufactured by: firstly, a hard thin material is tensioned and fixed on a screen frame in a screen stretching mode or a conventional metal wire screen printing plate is adopted and latex is coated; etching a main grid pattern on a hard thin material or latex, wherein the middle of a single main grid pattern is segmented to form a plurality of sections of main grid main body meshes which are distributed discontinuously, and each section of main grid main body mesh corresponds to the discontinuity between two adjacent sections of fine grid main body meshes which are crossed with the fine grid lines in the step (1); in the length direction of the main grid lines, adjacent two sections of main grid main body meshes are communicated through connecting wire meshes, and the width of each connecting wire mesh is smaller than that of each main grid main body mesh; or, in the length direction of the main grid lines, the fine grid main body meshes of two adjacent fine grid lines are communicated through connecting line meshes.

6. The method for manufacturing the conductive electrode wire of the solar cell according to claim 3, wherein in the step (1), the thickness of the hard thin material of the fine grid screen is 10-50 μm, and the area of the hard thin material is larger than that of the cell.

7. The method according to claim 3, wherein in the step (1), the length of the fine grid main body mesh is 5-30 mm, the width of the fine grid main body mesh is 10-40 μm, the interval between two adjacent fine grid main body meshes is 0.2-2 mm, and the grooving method is to chemically etch the hard thin material after laser engraving or mask lithography or to manufacture the hard thin material by using an electroforming process.

8. The method for manufacturing the conductive electrode line of the solar cell according to claim 3, wherein in the step (7), the curing temperature of the thin grid lines and the main grid lines for manufacturing the heterojunction cell is 200 ℃.

9. The method as claimed in claim 3, wherein in the step (7), the curing temperature of the fine grid lines is 700-900 ℃ and the curing temperature of the main grid lines is 200-900 ℃ for the PERC or TOPCon cell.

10. The method for manufacturing the conductive electrode wire of the solar cell according to claim 5, wherein the hard thin material is any one of a steel foil, a PI film and a PET film.

Technical Field

The invention relates to the technical field of solar cells, in particular to a distribution and manufacturing method of a conductive electrode wire of a solar cell.

Background

Photovoltaic power generation has become a technology that can replace fossil energy, relying on the ever-decreasing production costs and the increase in photoelectric conversion efficiency in recent years. Solar cells can be roughly classified into two types according to the material of the photovoltaic cell sheet: one is a crystalline silicon solar cell, including a monocrystalline silicon solar cell, a polycrystalline silicon solar cell; the other type is a thin film solar cell, which mainly comprises an amorphous silicon solar cell, a cadmium telluride solar cell, a copper indium gallium selenide solar cell and the like. At present, crystalline silicon solar cells using high-purity silicon materials as main raw materials are mainstream products, and account for more than 80%.

Currently, based on the manufacturing of crystalline silicon photovoltaic cells, referring to fig. 1, a plurality of conductive electrodes (called as thin grid line 11 electrodes or secondary grid electrodes) which are parallel to each other (usually 80-150 conductive electrodes), 20-50 μm in width and 10-25 μm in height are required to be manufactured on the surface of a cell 10 by a screen printing method for collecting photoelectrons generated by a silicon wafer cell when the silicon wafer cell is irradiated by sunlight; meanwhile, a plurality of (usually 2-20) main grid lines 12 with the width of 0.2-1.5 mm perpendicular to the thin grid line 11 electrodes are manufactured by a screen printing method and used for collecting current on the thin grid line 11 electrodes, the main grid lines 12 are finally welded with copper wires, and the copper wires lead out the current. One power generation cell can output current to the outside by taking the front main grid line 12 as one pole and the back main grid line 12 as one pole.

The fine grid lines 11 are generally arranged in 100 parallel on the surface of the battery. The more the thin grid lines are, the lower the current on a single line is, the smaller the resistance power loss is, the better the conductivity of the thin grid lines 11 is, and the power loss is smaller due to the resistance thereof during power generation. The thicker the thin grid lines, the lower the resistance, but the part covered by the thin grid lines cannot receive light to influence power generation, so the thicker the thin grid lines, the larger the number of the thin grid lines, the larger the covering area to influence the power generation amount, and meanwhile, the more the silver consumption, the higher the manufacturing cost. Therefore, the thinner and the larger the number of the fine grid lines, the more advantageous (the most efficient) is in power generation with the same total light-shielding area.

Referring to fig. 2, a screen used for screen printing is manufactured by coating a photosensitive emulsion 21 on a metal mesh fabric composed of metal wires 22, which is already tensioned in a metal frame, and then forming an opening line 20 on the emulsion by exposure and development using a film with a pattern, and during printing, the paste is transferred to a cell placed at the bottom through the opening line 20 under a pressing force, and the position and line width of a corresponding electrode of a silver line are printed by designing the position and line width of the opening line 20, so that the screen printing of the silver paste can be realized. The tensioned metal mesh and frame body with the patterned latex thereon is called a screen (as shown in fig. 2), and after the silver paste is printed on the surface of the cell, the silver paste is subjected to the necessary heating drying and higher temperature curing (or sintering) processes to form a conductive electrode for collecting and guiding out electrons generated by the illuminated cell.

Disclosure of Invention

In order to solve the technical problem, the invention firstly provides a distribution method of a solar cell conductive electrode wire, which comprises a main grid line and a fine grid line which are respectively printed on the surface of a cell; the core idea is to arrange the thin grid lines in a segmented manner, namely: the single thin grid line comprises a plurality of sections of thin grid main bodies which are distributed discontinuously in the length direction, and the thin grid main bodies which are discontinuous on two sides of the main grid line are connected in a conducting mode through the main grid line printed at the discontinuous part between the two adjacent sections of thin grid main bodies.

The invention also provides a manufacturing method of the solar cell conductive electrode wire with the structure, which comprises the following steps:

(1) manufacturing a fine grid screen printing plate: firstly, a hard thin material is tensioned and fixed on a net frame in a net stretching mode; etching a fine grid pattern on the hard thin material, and segmenting the middle of a single fine grid pattern to form a plurality of segments of intermittently distributed fine grid main body meshes, wherein the number of the segments corresponds to the number and the positions of the main grid lines, namely M main grid lines need to correspond to M +1 segments of fine grid main body meshes;

(2) manufacturing a main grid screen printing plate: because the width of the main grid line is larger, the conventional metal line screen printing plate can be completely applicable, and the hard thin material in the step (1) can also be adopted for manufacturing, and is not limited specifically;

(3) printing the fine grid line silver paste on the front surface of the cell by adopting the fine grid screen printing plate manufactured in the step (1) to form a discontinuous distribution fine grid main body;

(4) drying the discontinuous fine grid main body formed by printing in the step (3);

(5) printing corresponding main grid line silver paste on the front surface of the battery piece by adopting the main grid screen plate manufactured in the step (2) to form main grid lines which are connected in a conduction mode through the fine grid main bodies distributed discontinuously;

(6) drying the main grid line formed in the step (5);

(7) and (4) curing the main grid line and the fine grid main body after drying in the step (4) and the step (6).

And (3) to (6) are repeated for batteries such as HIT batteries and the like which need double-sided printing of electrode wires, the fine grid main body and the main grid lines are sequentially printed on the back of the battery piece, and then curing treatment is carried out together with the fine grid main body and the main grid lines printed on the front of the battery piece.

Further, the main grid lines can be arranged in a segmented mode according to needs, namely: the single main grid line comprises a plurality of sections of main grid main bodies distributed in an interrupted manner in the length direction, each section of main grid main body is used for conducting two adjacent sections of the same thin grid line, and the two adjacent parallel thin grid lines are in conducting connection through a connecting line.

Then, a manufacturing method of the solar cell conductive electrode wire based on the segmented distribution of the main grid lines is adopted, and in the step (2), the main grid screen printing plate is manufactured: firstly, a hard thin material is tensioned and fixed on a screen frame in a screen stretching mode or a conventional metal wire screen printing plate is adopted and latex is coated; etching a main grid pattern on a hard thin material or latex, wherein the middle of a single main grid pattern is segmented to form a plurality of sections of main grid main body meshes which are distributed discontinuously, and each section of main grid main body mesh corresponds to the discontinuity between two adjacent sections of fine grid main body meshes which are crossed with the fine grid lines in the step (1); in the length direction of the main grid lines, adjacent two sections of main grid main body meshes are communicated through connecting wire meshes, and the width of each connecting wire mesh is smaller than that of each main grid main body mesh; or, in the length direction of the main grid lines, the fine grid main body meshes of two adjacent fine grid lines are communicated through connecting line meshes.

Wherein, in the step (1), the thickness of the hard thin material of the fine grid screen printing plate is 10-50 μm, and the area of the hard thin material is larger than that of the battery piece; the length of the fine grid main body mesh is 5-30 mm, the width of the fine grid main body mesh is 10-40 mu m, the interval between two adjacent fine grid main body meshes is 0.2-2 mm, and the grooving method is to chemically corrode a hard thin material after laser engraving or mask photoetching or to manufacture the fine grid main body mesh by using an electroforming process.

Wherein, in the step (7), the curing temperature of the thin grid lines and the main grid lines is 200 ℃ when the heterojunction battery is manufactured; or the curing temperature of the thin grid lines is 700-900 ℃ and the curing temperature of the main grid lines is 200-900 ℃ when the thin grid lines are used for manufacturing a PERC or TOPCon battery.

Wherein, the hard thin material is made of any one of steel foil, PI film or PET film.

Through the technical scheme, the invention has the following advantages:

1) the width of the thin grid lines can be below 30 mu m, and phenomena of virtual printing and grid breakage are less, so that more thin grid lines can be arranged to reduce resistance and reduce shading area, battery efficiency is improved to increase generating capacity, and meanwhile, the use amount of silver paste is reduced to reduce the manufacturing cost of the battery;

2) any one of the steel foil, the PI film or the PET film for the screen printing plate has lower cost and long service life.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

FIG. 1 is a schematic diagram of a conductive electrode line distribution structure in the prior art;

FIG. 2 is a schematic diagram of a metal mesh screen of the prior art;

FIG. 3 is a schematic diagram of a hard thin material screen printing plate according to the prior art;

fig. 4 is a schematic view of a hard thin-material fine-grid screen printing plate according to an embodiment of the present invention;

fig. 5 is a schematic view illustrating a distribution structure of conductive electrode lines according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a hard thin material main grid screen according to an embodiment of the present invention;

fig. 7 is a schematic view of another conductive electrode line distribution structure disclosed in the embodiment of the present invention;

fig. 8 is a schematic view illustrating a distribution structure of another conductive electrode line according to an embodiment of the present invention;

fig. 9 is a schematic view of another conductive electrode line distribution structure according to an embodiment of the disclosure.

The figures in the drawings represent: 10. a battery piece; 11. a thin gate line; 12. a main gate line; 20. an opening line; 21. latex; 22. a metal wire; 23. net knots; 24. a small triangular area; 30. a hard sheet; 40. fine grid screen printing plate; 41. fine grid main body mesh; 50. a main grid screen plate; 51. main grid main body mesh; 52. connecting wire meshes; 60. a battery piece; 61. a fine gate body; 62. a main gate body; 63. and connecting the wires.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.