CN107718862A - Knotless screen plate for printing solar cell electrodes and preparation method thereof - Google Patents

Abstract

The invention discloses it is a kind of for printing solar cell electrode without net netting version and preparation method thereof, the half tone includes：The a plurality of warp along a direction extension；And a plurality of parallel extended along another direction, wherein, warp is parallel to each other and spaced apart, parallel is parallel to each other and spaced apart, warp and parallel weaving are provided with least one thin grid groove, warp is with parallel intersection formed with net knot into screen cloth between the lower section of screen cloth, adjacent warp or parallel, the bearing of trend of thin grid groove is parallel with the bearing of trend of warp or parallel so that the net knot falls in the outside of thin grid groove.According to the present invention, it can avoid net from bearing now on thin grid, easy network blocking during so as to solve to print electrode, printing height rise and fall big, thin grid empty print the problems such as, reduce the bad order rate of solar energy plate-making, improve yield rate, reduce production cost.

Description

Knotless screen plate for printing solar cell electrodes and preparation method thereof

technical field

The invention relates to the technical field of solar cell manufacturing, in particular to a knotless screen plate for printing solar cell electrodes and a preparation method thereof.

Background technique

Solar power generation is divided into photothermal power generation and photovoltaic power generation. Generally speaking, solar power generation refers to solar photovoltaic power generation, referred to as "photoelectricity". Photovoltaic power generation is a technology that directly converts light energy into electrical energy by using the photovoltaic effect at the semiconductor interface. The key element of this technology is the solar cell. The solar cells are packaged and protected after being connected in series to form a large-area solar cell module, and then cooperate with power controllers and other components to form a photovoltaic power generation device.

The electrodes of the solar cell are formed by screen printing, and the electrodes include at least one main grid and a plurality of fine grids perpendicular to the main grid and electrically connected to the main grid. The thin grids are parallel to each other and separated by a certain distance. As shown in Figure 1 and Figure 2, it is a printing screen plate of a solar cell electrode, including: a mesh cloth 11 woven into a plurality of mesh wires, an outer frame that is combined on the periphery of the mesh cloth 11 but not shown in the figure, And the emulsion layer 12 combined with the mesh cloth 11 and made of photoresist material. The mesh wires of the mesh cloth 11 are respectively a plurality of warp threads 111 that are approximately parallel to each other and extend at intervals in the front and rear directions, and a plurality of weft threads 112 that are perpendicular to the warp threads 111 and are woven interlacedly. The weft threads 112 are parallel to each other and spaced at a certain distance. The emulsion layer 12 has a plurality of elongated fine grid grooves 121 parallel to each other and at a certain distance (only one is shown in the figure). 111 are non-parallel, so that the fine grid groove 121 forms a certain angle with the extending direction of the meridian 111 . When printing electrodes, the electrode paste is coated on the mesh cloth 11, and the electrode paste is scraped by a scraper, so that the electrode paste passes through the mesh of the mesh cloth 11 and the fine grid groove 121 of the emulsion layer 12 to be drawn Coated on the surface of the battery, followed by high-temperature sintering, the slurry can be hardened to form an electrode, and the slurry at the fine grid groove 121 is hardened to form a fine grid.

Since the shape of the fine grid groove 121 and the angle between the extension direction of the fine grid groove 121 and the mesh wire will affect the extension direction and shape integrity of the fine grid at the forming place, the fine grid groove 121 and the 11 meshes of the mesh cloth The matching design of the angle is very important. Refer to Figure 3 (source: the article in the fourth issue of Volume 23 of "Printing Science and Technology" in Taiwan, China - page 30 of "Screen Printing Plate Inspection Process and Quality Control", citing the diagram of the ZBF technical manual), Figure ( a), (b), and (c) respectively show three kinds of screens, and the angle θ between the extension direction of the fine grid groove 121 of the emulsion layer 12 of each screen and its meridian is 22.5°, 45° and 0° respectively , Figures (d), (e), and (f) correspond to the fine grids 10 printed using the screens of Figures (a), (b), and (c) respectively. It has been found through experiments that the electrode leads 10 printed by the screen printing shown in figure (a) have the most complete shape and the best quality, while the fine grid grooves 121 and warp lines 111 in figure (c) are arranged in parallel, and the quality of the printed electrodes is not good. Preferably, this is because the intersection of warp 111 and weft 112 inevitably forms a net knot, and the net knot makes the mesh cloth 11 form a regular concave-convex surface. And, the thickness of the mesh wire without the mesh junction is smaller than the mesh wire thickness at the mesh junction. In screen printing, the farther the mesh wire is from the mesh junction, the easier it is for the electrode paste to fall smoothly, but it is not the case near the mesh junction. These The position electrode paste is easy to be blocked by the net knot or the paste remains on the net knot. As a result, the electrode paste thickness of the fine grid will be uneven or even intermittent, especially after a certain amount of screen printing is used, the electrode paste thickness is not The problem of equalization will be highlighted.

Referring to Figure (a) and Figure (b), when there is a certain angle between the warp 11 of the mesh cloth 11 and the fine grid groove 121 of the emulsion layer 12, the net knots fall on the fine grid groove 121 less, and when squeegeeing The slurry is less blocked by the net knots. Referring to Figure (c), when the warp 11 of the mesh cloth 11 is parallel to the fine grid groove 121 of the emulsion layer 12, the net knots fall on the fine grid groove 121 the most, and the slurry will It is more blocked by the network knot, which affects the forming of the fine grid. Therefore, when making the screen plate at present, a certain angle must be formed between the warp threads 111 of the mesh cloth 11 and the fine grid grooves 121 of the emulsion layer 112 . And when there is a certain angle between the warp 111 of the mesh cloth 11 and the fine grid groove 121 of the emulsion layer 112, although there are fewer net knots falling on the fine grid groove 121, a considerable part of the net knots still falls on the fine grid. On the groove 121, in the actual production process, after a certain amount is printed with the screen, the problem of uneven thickness of the electrode paste will be highlighted. In view of this, it is necessary to develop a meshless screen for printing solar cell electrodes and a preparation method thereof to solve the above problems.

Contents of the invention

Aiming at the deficiencies existing in the prior art, the object of the present invention is to provide a kind of non-network screen plate for printing solar cell electrodes and its preparation method, which can avoid network knots appearing on the fine grid, thereby solving the printing problem. It is easy to block the screen when the electrode is used, the printing height fluctuates greatly, and the fine grid virtual printing and other problems can reduce the appearance defect rate of solar plate making, improve the yield rate, and reduce the production cost.

In order to achieve the above-mentioned purpose and other advantages according to the present invention, a kind of knotless screen for printing solar cell electrodes is provided, comprising:

Multiple meridians extending in one direction; and

multiple parallels extending in the other direction,

Wherein, the warp threads are parallel to each other and at a certain distance apart, the weft threads are parallel to each other and at a certain distance apart, and the warp threads and weft threads are interlaced to form a mesh cloth. A net knot is formed at the intersection, and the extending direction of the fine grid groove is parallel to the extending direction of the warp or weft thread, so that the net knot falls on the outside of the fine grid groove.

Preferably, the fine grid groove is arranged between two adjacent warps.

Preferably, the fine grid groove is arranged between two adjacent weft threads.

Preferably, the width of the fine grid groove is not greater than 15 microns.

Preferably, the distance between the two sides of the fine grid groove and the warp or weft is not less than 10 microns.

Preferably, the fine grid slots are electrically connected with multiple main grids parallel to each other, and the mesh cloth is woven with multiple anti-break grid lines, and the anti-break grid lines do not intersect with the mesh nodes.

Preferably, border lines are incorporated at the edges of the mesh.

Preferably, the warps and wefts are perpendicular to each other, the distance between adjacent warps is 25-80 microns, and the distance between adjacent wefts is 25-80 microns.

Further. This case also provides a kind of method for preparing the above-mentioned non-network screen plate for printing solar cell electrodes, it is characterized in that, comprises the following steps:

Step 1, weaving the warp and weft into a mesh according to the predetermined layout;

Step 2, setting the fine grid groove between two adjacent warp threads or two weft threads;

Step 3, adding the main grid, anti-break grid lines, and border lines on the mesh according to the predetermined design.

The present invention compares with prior art, and its beneficial effect is:

It can avoid network knots from appearing on the fine grid, thereby solving the problems of easy grid blocking when printing electrodes, large printing height fluctuations, and fine grid virtual printing, etc., reducing the appearance defect rate of solar plate making, improving the yield rate, and reducing production costs. The screen plate improves the conversion efficiency of the cell.

Description of drawings

Fig. 1 is a partial top view of a known screen;

Fig. 2 is a sectional view taken along the direction 2-2 in Fig. 1;

(a), (b), and (c) in Figure 3 show three different screens, and (d), (e), and (f) correspond to the use of Figures (a), (b), and (c) respectively. Electrode wires printed by screen;

Fig. 4 is a top view of a meshless screen for printing solar cell electrodes according to the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings, and the aforementioned and other objects, features, aspects and advantages of the present invention will become more apparent, so that those skilled in the art can implement them with reference to the description.

Referring to Figure 4, the knotless screen for printing solar cell electrodes includes:

a plurality of meridians 211 extending in one direction; and

a plurality of weft threads 212 extending in another direction,

Wherein, the warp threads 211 are parallel to each other and at a certain distance apart, the weft threads 212 are parallel to each other and at a certain distance apart, the warp threads 211 and the weft threads 212 are interlaced to form the mesh cloth 21, and at least A fine grid groove 221, a mesh knot is formed at the intersection of the warp thread 211 and the weft thread 212, and the extension direction of the fine grid groove 221 is parallel to the extension direction of the warp thread 211 or the weft thread 212, so that the mesh knot falls on the outside of the fine grid groove 221 . In one embodiment, the scrim 21 incorporates an emulsion layer 22 made of photoresist material.

In a preferred embodiment, the fine grid groove 221 is disposed between two adjacent meridians 211 .

In another embodiment, the fine grid groove 221 is disposed between two adjacent weft threads 212 (not shown).

Further, the width of the fine grid groove 221 is not greater than 15 microns, and the distance between the two sides of the fine grid groove 221 and the warp 211 or the weft 212 is not less than 10 microns. In a preferred embodiment, the width of the fine grid groove 221 is 15 microns, the height is 30 microns, and the distance between the two sides of the fine grid groove 221 and the warp 211 or weft 212 is 10 microns.

Further, a plurality of main grids parallel to each other (not shown in the figure) are electrically connected between the fine grid grooves 221, and a plurality of anti-break grid wires (not shown in the figure) are woven on the mesh cloth 21. Broken grid lines do not intersect the mesh nodes.

Further, the edges of the mesh cloth 21 are combined with frame lines.

Referring to FIG. 4 again, the warps 211 and the wefts 212 are perpendicular to each other, the distance between adjacent warps 211 is 25-80 microns, and the distance between adjacent wefts 212 is 25-80 microns. In a preferred embodiment, the distance between adjacent warp threads 211 is 28 microns, and the distance between adjacent weft threads 212 is 28 microns.

Further, this case also discloses a method for preparing the above-mentioned knotless screen for printing solar cell electrodes, comprising the following steps:

Step 1, weaving warp threads 211 and weft threads 212 interlacedly into mesh cloth 21 according to a predetermined format;

Step 2, setting the fine grid groove 221 between two adjacent warp threads 211 or two weft threads 212;

Step 3, adding the main grid, anti-break grid lines, and border lines on the mesh cloth 21 according to a predetermined design.

The knotless screen plate used for printing solar battery electrodes prepared according to the invention can increase the conversion efficiency of battery sheets by more than 0.08%.

The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations to the present invention will be apparent to those skilled in the art.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the use listed in the specification and implementation, it can be applied to various fields suitable for the present invention, and it can be easily understood by those skilled in the art Further modifications can be effected, so the invention is not limited to the specific details and examples shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims (9)

1. a kind of knot version for printing solar cell electrode without net, it is characterised in that including：

The a plurality of warp (211) along a direction extension；And

The a plurality of parallel (212) extended along another direction,

Wherein, warp (211) is parallel to each other and spaced apart, and parallel (212) is parallel to each other and spaced apart, warp (211) with parallel (212) weaving into screen cloth (21), lower section, adjacent warp (211) or the parallel (212) of screen cloth (21) it Between be provided with least one thin grid groove (221), warp (211) is tied with parallel (212) intersection formed with net, thin grid groove (221) Bearing of trend is parallel with the bearing of trend of warp (211) or parallel (212) so that the net knot falls in thin grid groove (221) Outside.

2. as claimed in claim 1 for printing solar cell electrode without net netting version, it is characterised in that thin grid groove (221) it is located between adjacent two warps (211).

3. as claimed in claim 1 for printing solar cell electrode without net netting version, it is characterised in that thin grid groove (221) it is located between adjacent two parallels (212).

4. as claimed in claim 1 for printing solar cell electrode without net netting version, it is characterised in that thin grid groove (221) width is not more than 15 microns.

5. as claimed in claim 1 for printing solar cell electrode without net netting version, it is characterised in that thin grid groove (221) both sides from a distance from warp (211) or parallel (212) be not less than 10 microns.

6. as claimed in claim 1 for printing solar cell electrode without net netting version, it is characterised in that thin grid groove (221) a plurality of main grid parallel to each other is electrically connected between, a plurality of anti-breaking grid line, the anti-breaking grid line are woven with screen cloth (21) It is non-intersect with the net knot.

7. as claimed in claim 6 for printing solar cell electrode without net netting version, it is characterised in that screen cloth (21) Edge be combined with frame line.

8. as claimed in claim 7 for printing solar cell electrode without net netting version, it is characterised in that warp (211) it is mutually perpendicular to parallel (212), the distance between adjacent warp (211) is 25~80 microns, between adjacent parallel (212) Distance is 25~80 microns.

9. a kind of preparation method without net netting version as claimed in claim 8 for printing solar cell electrode, it is special Sign is, comprises the following steps：

Step 1, warp (211) and parallel (212) are pressed into predetermined format weaving into screen cloth (21)；

Step 2, thin grid groove (221) is located between adjacent two warps (211) or two parallels (212)；

Step 3, the main grid, anti-breaking grid line and frame line are added on screen cloth (21) by predetermined design.