阅读说明：本技术 一种太阳能电池栅线偏移的调整方法及其应用 (Method for adjusting solar cell grid line offset and application thereof ) 是由 丰明璋 林纲正 陈刚 于 2020-05-09 设计创作，主要内容包括：本发明公开了一种太阳能电池栅线偏移的调整方法,其包括采用网版将栅线印刷到硅片上；分别测量相邻激光槽之间的距离x和相邻栅线中心之间的距离y<Sub>1</Sub>,相邻栅线端点之间的距离y<Sub>2</Sub>；计算激光槽与栅线之间的第一偏移间距δ<Sub>1</Sub>和第二偏移间距δ<Sub>2</Sub>；根据偏移间距情况进行判断,并对网版PT值和/或张力值进行调节。相应的,本发明还公开了上述太阳能电池栅线偏移的调整方法在太阳能电池生产过程中的应用。本发明的调整方法,可明显减少或消除电极栅线与激光槽的偏移,在满足电池外观要求的同时,提升电极栅线对于载流子的收集能力。(The invention discloses a method for adjusting the offset of a grid line of a solar cell, which comprises the steps of printing the grid line on a silicon chip by adopting a screen printing plate; respectively measuring the distance x between adjacent laser grooves and the distance y between the centers of adjacent grating lines 1 Distance y between end points of adjacent grid lines 2 (ii) a Calculating a first offset distance between the laser groove and the gate line 1 And a second offset pitch 2 (ii) a And judging according to the offset space condition, and adjusting the PT value and/or the tension value of the screen printing plate. Correspondingly, the invention also discloses an application of the solar cell grid line deviation adjusting method in a solar cell production process. The adjusting method can obviously reduce or eliminate the deviation of the electrode grid line and the laser groove, meets the appearance requirement of the battery, and simultaneously improves the collection energy of the electrode grid line to current carriersForce.)

1. A method for adjusting the deviation of a grid line of a solar cell is characterized by comprising the following steps:

(1) printing a grid line on a silicon wafer by adopting a screen printing plate, wherein the silicon wafer is provided with a laser groove;

(2) measuring the distance x between adjacent laser grooves;

(3) measuring the distance y between the centers of adjacent grid lines₁Distance y between end points of adjacent grid lines₂；

(4) Calculating a first offset distance between the laser groove and the gate line₁And a second offset pitch₂；

Wherein, the offset distance between the laser groove and the grid line is calculated according to the following formula group:

₁＝x-y₁

₂＝x-y₂

wherein the content of the first and second substances,₁a first offset spacing between the laser trench and the gate line,₂is the second offset distance between the laser groove and the grid line, x is the distance between adjacent laser grooves, y₁Is the distance between the centers of adjacent grid lines, y₂Is the distance between the end points of adjacent grid lines;

(5) adjusting the parameters of the screen printing plate according to the offset distance condition;

wherein when₁Is equal to 0 and₂when the value is equal to 0, the parameters of the screen printing plate are not adjusted;

when in use₁Is equal to 0 and₂when not equal to 0, adjusting the tension value of the screen printing plate;

when in use₁Not equal to 0 and₂and when the value is not equal to 0, adjusting the PT value and/or the tension value of the screen printing plate.

2. The method of claim 1, wherein step (3) further comprises measuring the distance y between adjacent grid lines 1/4 along their lengths₃；

The step (4) further comprises calculating a third offset distance between the laser groove and the grid line₃；

Wherein, the third offset distance between the laser groove and the grid line is calculated according to the following formula:

₃＝x-y₃

wherein the content of the first and second substances,₃is the third offset distance between the laser groove and the grid line, x is the distance between adjacent laser grooves, y₃Is the distance at the length of the adjacent grid line 1/4.

3. The method for adjusting solar cell grid line shift according to claim 2, wherein in the step (5):

when in use₁＝0，₂Is equal to 0 and₃when the value is equal to 0, the parameters of the screen printing plate are not adjusted;

when in use₁＝0，₂Not equal to 0 and₃when not equal to 0, only adjusting the tension value of the screen printing plate;

when in use₁≠0，₂Not equal to 0 and₃and (4) not equal to 0, adjusting the PT value and/or the tension value of the screen printing plate.

4. The method for adjusting solar cell grid line shift according to claim 2, wherein in the step (5):

when in use₁Not equal to 0, and₁＝₂＝₃only adjusting the PT value of the screen printing plate;

when in use₁≠0，₂≠0，₃≠0，₁≠₂And is₂≠₃When in use, the PT value of the screen printing plate is adjusted, and then the tension of the screen printing plate is adjusted.

5. The method for adjusting the solar cell grid line shift according to claim 1, wherein in the step (5):

when in use₁≠0，₂≠0，₃Not equal to 0, and₁＝₂＝₃only adjusting the PT value of the screen printing plate; wherein, adjust the screen PT value according to the following formula:

PT_A＝PT_B+(N-1)₁

wherein PT_ATo adjust the PT value of the rear screen, PT_BIn order to adjust the PT value of the front screen, N is the total number of the lines of the screen,₁is a first offset spacing between the laser trench and the gate line.

6. The method of claim 1, wherein in step (5), when the solar cell grid line shift is adjusted₁＝0，₂≠0，₃Not equal to 0 and₂≠₃adjusting the tension value of the screen printing plate;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂a second offset spacing between the laser trench and the gate line,₃is a third offset spacing between the laser trench and the gate line.

7. The method of claim 2, wherein in step (5), when the solar cell grid line shift is adjusted₁＝0，₂≠0，₃Not equal to 0 and₂＝₃adjusting the tension value of the screen printing plate;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂is a second offset spacing between the laser trench and the gate line.

8. The method for adjusting solar cell grid line shift according to claim 2, wherein in the step (5):

when in use₁≠0，₂≠0，₃≠0，₁≠₂，₁≠₃And is and₂＝₃firstly, adjusting the PT value of the screen printing plate, and then adjusting the tension value of the screen printing plate;

wherein, adjust the screen PT value according to the following formula:

PT_A＝PT_B+(N-1)₁

wherein PT_ATo adjust the PT value of the rear screen, PT_BIn order to adjust the PT value of the front screen, N is the total number of the lines of the screen,₁a first offset distance between the laser groove and the grid line;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂is a second offset spacing between the laser trench and the gate line.

9. The method for adjusting solar cell grid line shift according to claim 2, wherein in the step (5):

when in use₁≠0，₂Not equal to 0 and₃≠0，₁≠₂，₁≠₃and is and₂≠₃firstly, adjusting the PT value of the screen printing plate, and then adjusting the tension value of the screen printing plate;

wherein, adjust the screen PT value according to the following formula:

PT_A＝PT_B+(N-1)₁

wherein PT_ATo adjust the PT value of the rear screen, PT_BIn order to adjust the PT value of the front screen, N is the total number of the lines of the screen,₁a first offset distance between the laser groove and the grid line;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂a second offset spacing between the laser trench and the gate line,₃is a third offset spacing between the laser trench and the gate line.

10. Use of the method of any one of claims 1 to 9 for adjusting solar cell grid line shift in a solar cell production process.

Technical Field

The invention relates to the field of solar cell electrode printing, in particular to a solar cell grid line offset adjusting method and application.

Background

The screen printing is a commonly used solar cell printing technology at present, and the basic operation flow is as follows: the silicon chip with the laser groove is placed on a workbench, slurry is poured into a screen printing plate above the workbench, then a scraper is used for applying certain pressure on the screen printing plate, the scraper moves towards the other end from one end of the screen printing plate, and the slurry can be extruded onto the silicon chip from meshes of the pattern part, so that screen printing is completed. In the current printing process, the printing effect is mostly adjusted through parameters such as printing pressure, printing space, printing speed and printing height.

On the other hand, with the development of solar cell technology, a laser heavy doping technology and a PERC cell technology gradually appear, and the two technologies have in common that part/all of electrode grid lines are printed in laser grooves which are punched at the previous stage. When the electrode grid line is printed by screen printing, the alignment position is required, which puts high requirements on the screen printing process. The existing screen printing process is often large in deviation when laser slot printing is carried out, so that the requirement on the appearance of a battery piece cannot be met, and the difficulty in collecting carriers and the carrier transmission loss are easily caused.

Disclosure of Invention

The invention aims to provide a method for adjusting the deviation of a solar cell grid line, which can effectively reduce or eliminate the deviation between an electrode grid line and a laser groove and improve the appearance and the conversion efficiency of a solar cell.

The invention also provides an application of the method for adjusting the grid line offset of the solar cell in a solar cell process.

In order to solve the above problem, the present invention discloses a method for adjusting the offset of a solar cell grid line, which comprises:

(1) printing a grid line on a silicon wafer by adopting a screen printing plate, wherein the silicon wafer is provided with a laser groove;

(2) measuring the distance x between adjacent laser grooves;

(3) measuring the distance y between the centers of adjacent grid lines₁Distance y between end points of adjacent grid lines₂；

(4) Calculating a first offset distance between the laser groove and the gate line₁And a second offset pitch₂；

Wherein, the offset distance between the laser groove and the grid line is calculated according to the following formula group:

₁＝x-y₁

₂＝x-y₂

wherein the content of the first and second substances,₁a first offset spacing between the laser trench and the gate line,₂is the second offset distance between the laser groove and the grid line, x is the distance between adjacent laser grooves, y₁Is the distance between the centers of adjacent grid lines, y₂Is the distance between the end points of adjacent grid lines;

(5) adjusting the parameters of the screen printing plate according to the offset distance condition;

wherein when₁Is equal to 0 and₂when the value is equal to 0, the parameters of the screen printing plate are not adjusted;

when in use₁Is equal to 0 and₂when not equal to 0, adjusting the tension value of the screen printing plate;

when in use₁Not equal to 0 and₂and when the value is not equal to 0, adjusting the PT value and/or the tension value of the screen printing plate.

As an improvement to the above solution, step (3) further comprises measuring the distance y between adjacent grid lines 1/4₃；

The step (4) also comprises the step of calculating the distance between the laser groove and the grid line₃；

Wherein, the third offset distance between the laser groove and the grid line is calculated according to the following formula:

₃＝x-y₃

wherein the content of the first and second substances,₃is the third offset distance between the laser groove and the grid line, x is the distance between adjacent laser grooves, y₃Is the distance at the length of the adjacent grid line 1/4.

As an improvement of the above technical solution, in the step (5):

when in use₁＝0，₂Is equal to 0 and₃when the value is equal to 0, the parameters of the screen printing plate are not adjusted;

when in use₁＝0，₂Not equal to 0 and₃when not equal to 0, only adjusting the tension value of the screen printing plate;

when in use₁≠0，₂Not equal to 0 and₃and (4) not equal to 0, adjusting the PT value and/or the tension value of the screen printing plate.

As an improvement of the above technical solution, in the step (5):

when in use₁Not equal to 0, and₁＝₂＝₃only adjusting the PT value of the screen printing plate;

when in use₁≠0，₂≠0，₃≠0，₁≠₂And is₂≠₃When in use, the PT value of the screen printing plate is adjusted, and then the tension of the screen printing plate is adjusted.

As an improvement of the above technical solution, in the step (5):

when in use₁≠0，₂≠0，₃Not equal to 0, and₁＝₂＝₃only adjusting the PT value of the screen printing plate; wherein, adjust the screen PT value according to the following formula:

PT_A＝PT_B+(N-1)₁

wherein PT_ATo adjust the PT value of the rear screen, PT_BIn order to adjust the PT value of the front screen, N is the total number of the lines of the screen,₁is a first offset spacing between the laser trench and the gate line.

As an improvement of the above technical scheme, in the step (5), when₁＝0，₂≠0，₃Not equal to 0 and₂≠₃adjusting the tension value of the screen printing plate;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂a second offset spacing between the laser trench and the gate line,₃is a third offset spacing between the laser trench and the gate line.

As an improvement of the above technical scheme, in the step (5), when₁＝0，₂≠0，₃Not equal to 0 and₂＝₃adjusting the tension value of the screen printing plate;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂is a second offset spacing between the laser trench and the gate line.

As an improvement of the above technical solution, in the step (5):

when in use₁≠0，₂≠0，₃≠0，₁≠₂，₁≠₃And is and₂＝₃firstly, adjusting the PT value of the screen printing plate, and then adjusting the tension value of the screen printing plate;

wherein, adjust the screen PT value according to the following formula:

PT_A＝PT_B+(N-1)₁

wherein PT_ATo adjust the PT value of the rear screen, PT_BIn order to adjust the PT value of the front screen, N is the total number of the lines of the screen,₁a first offset distance between the laser groove and the grid line;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂is a second offset spacing between the laser trench and the gate line.

As an improvement of the above technical solution, in the step (5):

when in use₁≠0，₂Not equal to 0 and₃≠0，₁≠₂，₁≠₃and is and₂≠₃firstly, adjusting the PT value of the screen printing plate, and then adjusting the tension value of the screen printing plate;

wherein, adjust the screen PT value according to the following formula:

PT_A＝PT_B+(N-1)₁

wherein PT_ATo adjust the PT value of the rear screen, PT_BIn order to adjust the PT value of the front screen, N is the total number of the lines of the screen,₁a first offset distance between the laser groove and the grid line;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂a second offset spacing between the laser trench and the gate line,₃is a third offset spacing between the laser trench and the gate line.

Correspondingly, the invention also discloses an application of the solar cell grid line deviation adjusting method in a solar cell production process.

The implementation of the invention has the following beneficial effects:

1. according to the adjusting method, through adjusting two parameters of the screen tension value and the screen PT value, the offset between the electrode grid line and the laser groove is effectively reduced/eliminated, the appearance performance of the solar cell is improved, the collecting capacity and the transporting capacity of the cell to current carriers are also improved, and the conversion efficiency of the solar cell is improved.

2. The adjusting method comprises the following steps: and (3) trial printing, measuring the space, determining which screen parameters to adjust according to the space, and quantitatively adjusting the parameters according to the space. The adjusting method is simple and clear, has strong industrial operability and is easy to popularize.

3. The adjusting method reduces the offset between the laser groove and the electrode grid line; the width of the traditional laser groove is reduced, and the risk of silicon chip subfissure is reduced.

Drawings

Fig. 1 is a flowchart of a method for adjusting a solar cell grid line offset according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below.

Conventional screen printing is prone to shifting when printing electrode grid lines to a laser slot. And it is difficult to reduce or eliminate such offset by conventional adjustment means. To this end, the present invention provides a method for adjusting solar grid line offset, referring to fig. 1, which includes:

s1: printing the grid line on a silicon chip by adopting a screen printing plate;

specifically, a grid line is printed on a silicon chip in a trial mode by adopting a screen printing plate; wherein, a plurality of laser grooves which are parallel to each other are arranged on the silicon chip.

Specifically, the width of the laser groove is 80 to 250 μm, preferably 80 to 150 μm, and may be, for example, 80, 95, 100, 110, 115, 125, 130, 140 μm, but is not limited thereto.

S2: measuring the distance x between adjacent laser grooves;

specifically, a three-dimensional microscope is adopted to measure the distance x between adjacent laser grooves on the surface of the silicon wafer. Here, the distance between adjacent laser grooves refers to the distance between the laser groove center lines.

Specifically, the width of the grid line is 50-150 μm, and is exemplarily 50, 60, 80, 95, 110, 115 μm, but is not limited thereto.

S3: measuring the distance between adjacent grid lines;

specifically, in the present invention, the distance between adjacent gate lines is characterized by the following three ways:

distance y between centers of adjacent grid lines₁Distance y between end points of adjacent grid lines in the same direction₂And the distance y of the adjacent gate line 1/4₃. Through the distance of the three points, the deviation condition of the grid line relative to the laser groove can be reasonably evaluated, and a good data basis is provided for later adjustment. It should be noted that, the distance between the grid lines herein refers to the distance between the center lines of the grid lines.

S4: calculating the offset distance between the laser groove and the grid line;

specifically, in the present invention, the offset distance between the gate line and the laser groove can be characterized in the following three ways:

first offset spacing between laser groove and grid line center point₁Second offset spacing between laser grooves and grid line end points₂And a third offset spacing of the laser grooves from the length of the grid line 1/4₃. In particular, the method comprises the following steps of,

calculating the offset distance between the laser groove and the grid line according to the following formula group:

₁＝x-y₁

₂＝x-y₂

₃＝x-y₃

s5: adjusting the parameters of the screen printing plate according to the offset distance condition;

specifically, the inventor finds that the offset between the laser groove and the grid line can be improved by adjusting the PT value and the tension value of the screen plate in the actual adjusting process. However, how to determine the adjustment target, i.e., how to determine whether to adjust the screen PT value or the screen tension value, or to adjust both values at the same time? Is the first problem to be solved. Further, after the adjustment target is determined, how to quantitatively adjust the screen PT value and/or the screen tension value according to the offset condition is a second problem to be solved. For this purpose, the invention proposes the following solutions:

specifically, in an embodiment of the present invention, the adjustment object is determined according to the following method:

when in use₁Is equal to 0 and₂when the value is equal to 0, the parameters of the screen printing plate are not adjusted;

when in use₁Is equal to 0 and₂when not equal to 0, adjusting the tension value of the screen printing plate;

when in use₁Not equal to 0 and₂and when the value is not equal to 0, adjusting the PT value and the tension value of the screen printing plate.

Namely, the adjustment object is determined according to the first offset distance and the second offset distance.

In another embodiment of the present invention, the adjustment object may be determined according to the following method:

when in use₁＝0，₂Is equal to 0 and₃when the value is equal to 0, the parameters of the screen printing plate are not adjusted;

when in use₁＝0，₂Not equal to 0 and₃when not equal to 0, only adjusting the tension value of the screen printing plate;

when in use₁≠0，₂Not equal to 0 and₃and (4) not equal to 0, adjusting the PT value and/or the tension value of the screen printing plate.

Namely, the adjustment object is determined according to the first offset pitch, the second offset pitch and the third offset pitch.

In yet another embodiment of the present invention, the adjustment object may be determined according to the following method:

when in use₁＝0，₂Is equal to 0 and₃when the value is equal to 0, the parameters of the screen printing plate are not adjusted;

when in use₁＝0，₂Not equal to 0 and₃when not equal to 0, only adjusting the tension value of the screen printing plate;

when in use₁Not equal to 0, and₁＝₂＝₃only adjusting the PT value of the screen printing plate;

when in use₁≠0，₂≠0，₃≠0，₁≠₂And is₂≠₃When in use, the PT value of the screen printing plate is adjusted, and then the tension of the screen printing plate is adjusted.

Namely, the adjustment object is determined according to the first offset pitch, the second offset pitch and the third offset pitch.

Accordingly, after determining the adjustment target, the specific adjustment amount needs to be determined:

in particular, when₁≠0，₂≠0，₃Not equal to 0, and₁＝₂＝₃only adjusting the PT value of the screen printing plate; wherein, adjust the screen PT value according to the following formula:

PT_A＝PT_B+(N-1)₁

wherein PT_ATo adjust the PT value of the rear screen, PT_BIn order to adjust the PT value of the front screen, N is the total number of the lines of the screen,₁is a first offset spacing between the laser trench and the gate line.

In particular, when₁＝0，₂≠0，₃Not equal to 0 and₂≠₃adjusting the tension value of the screen printing plate;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂a second offset spacing between the laser trench and the gate line,₃is a third offset spacing between the laser trench and the gate line.

In particular, when₁＝0，₂≠0，₃Not equal to 0 and₂＝₃adjusting the tension value of the screen printing plate;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂is the second between the laser groove and the grid lineThe pitch is offset.

In particular, when₁≠0，₂≠0，₃≠0，₁≠₂，₁≠₃And is and₂＝₃firstly, adjusting the PT value of the screen printing plate, and then adjusting the tension value of the screen printing plate;

wherein, adjust the screen PT value according to the following formula:

PT_A＝PT_B+(N-1)₁

wherein PT_ATo adjust the PT value of the rear screen, PT_BIn order to adjust the PT value of the front screen, N is the total number of the lines of the screen,₁a first offset distance between the laser groove and the grid line;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂is a second offset spacing between the laser trench and the gate line.

In particular, when₁≠0，₂Not equal to 0 and₃≠0，₁≠₂，₁≠₃and is and₂≠₃firstly, adjusting the PT value of the screen printing plate, and then adjusting the tension value of the screen printing plate;

wherein, adjust the screen PT value according to the following formula:

PT_A＝PT_B+(N-1)₁

wherein PT_ATo adjust the PT value of the rear screen, PT_BIn order to adjust the PT value of the front screen, N is the total number of the lines of the screen,₁a first offset distance between the laser groove and the grid line;

wherein, adjust the screen tension value according to the following formula:

wherein, F_AFor adjusting the tension value of the rear screen, F_BIn order to adjust the tension value of the front screen,₂a second offset spacing between the laser trench and the gate line,₃is a third offset spacing between the laser trench and the gate line.

According to the adjusting method, the tension value and PT value of the screen can be reasonably adjusted according to the size of the offset space. After the adjustment, a second trial printing is performed, and if there is an offset, the steps S1 to S5 are repeated until the offset between the laser groove and the grid line is eliminated. By the adjusting method, the effect of eliminating the offset between the laser groove and the grid line can be achieved by generally performing 2-3 times of test printing.

In addition, it should be noted that in the conventional printing process, in order to reduce the offset, the width (120-300 μm) of the laser groove is generally widened, which increases the area occupied by a single laser groove, and in order to widen the width of the laser groove, multiple times of laser processing are often required at the same position, which increases the probability of silicon wafer subfissure. The adjusting method can effectively reduce the offset, thereby reducing the width of the laser groove, reducing the repeated laser processing and reducing the risk of silicon chip subfissure.

Correspondingly, the invention also discloses an application of the solar cell grid line deviation adjusting method in a solar cell production process.

Specifically, the solar cell may be a PERC cell, an SE cell or an SE-PERC cell. In the SE battery, a front side auxiliary gate electrode is printed in a heavily doped laser groove; in the PERC cell, the back side subgrid is printed in the laser groove.

Specifically, the solar cell may be a single-sided cell or a double-sided cell.

Specifically, the adjusting method of the present invention is applicable to a single printing process and also applicable to a batch printing process.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.