WO2012057267A1

WO2012057267A1 - Method for producing solar cell, and printing plate

Info

Publication number: WO2012057267A1
Application number: PCT/JP2011/074824
Authority: WO
Inventors: 平　茂治
Original assignee: 三洋電機株式会社
Priority date: 2010-10-27
Filing date: 2011-10-27
Publication date: 2012-05-03
Also published as: JP2014013783A

Abstract

[Problem] To provide a method capable of producing a solar cell having high photoelectric conversion characteristics. [Solution] The downstream end part (21a1) of a first opening (21) comprises a first portion (23) and a second portion (24). The downstream end part (21a1) is the end part on the side of a second opening (22a) in a downstream portion positioned further to the other side in one direction (y) than the second opening. The first portion (23) tapers in the direction from a first main surface (20a) of a printing plate (20) on the side opposite from a photoelectric conversion unit (10) toward a second main surface (20b) on the side of the photoelectric conversion unit (10). The second portion (24) is positioned further toward the photoelectric conversion unit (10) than the first portion (23). The second portion (24) has an aperture surface area equivalent to the opening surface area of that end of the first portion (23) which is on the side of the photoelectric conversion unit (10).

Description

Solar cell manufacturing method and printing plate

The present invention relates to a method for manufacturing a solar cell and a printing plate suitably used for manufacturing a solar cell.

In recent years, solar cells have attracted a great deal of attention as an energy source with a low environmental impact. The solar cell includes a photoelectric conversion unit that generates carriers by receiving light, and an electrode that collects carriers generated by the photoelectric conversion unit. As an electrode, an electrode having a plurality of finger portions and a bus bar portion electrically connected to the plurality of finger portions (hereinafter, may be referred to as “comb electrode”) is widely used.

As a method for forming a comb-shaped electrode, Patent Document 1 proposes a method of forming by screen printing. In this document, as a screen printing plate for forming a comb-shaped electrode, a printing plate in which a width of one side portion of a connecting portion with respect to an opening for forming a bus bar portion is smaller than a width of the other side portion among the openings for forming a finger portion It has been proposed to use By using this screen printing plate and moving the squeegee from the other side to the one side to perform electrode printing, it is possible to prevent the connection portion of the finger portion with the bus bar portion from becoming thicker than the other portions.

Japanese Patent No. 4391803

However, in the screen printing plate described in Patent Document 1, it is difficult to reduce the width of the finger part because a part of the opening for forming the finger part is narrower than the other part.

Also, since a part of the opening for forming the finger part is made wider than the other part, the electrode formation tends to spread and spread when the finger part is formed. For this reason, it is difficult to reduce the width of the finger portion.

The manufacturing method of the solar cell which concerns on 1 aspect of this invention is equipped with the photoelectric conversion part and the electrode distribute | arranged on one main surface of the photoelectric conversion part, an electrode is extended to one direction, and an electric power is supplied to a finger part. In particular, the present invention relates to a method of manufacturing a solar cell having a bus bar portion that is connected to each other and intersects a finger portion. The method for manufacturing a solar cell according to one aspect of the present invention includes a step of placing a printing plate on one main surface of a photoelectric conversion unit, a conductive paste on the printing plate, and a squeegee in one direction. Forming an electrode by moving from the side toward the other side. The printing plate has a first opening and a second opening. The first opening is an opening corresponding to the finger portion. The second opening is an opening corresponding to the bus bar portion. The second opening intersects the first opening. The downstream end that is the second opening side end of the downstream portion located on the other side of the second opening of the first opening includes a first portion and a second portion. The first portion tapers from the first main surface opposite to the photoelectric conversion unit of the printing plate toward the second main surface side on the photoelectric conversion unit side. The second part is located closer to the photoelectric conversion unit than the first part. The second portion has an opening area equal to the opening area at the tip of the first portion on the photoelectric conversion unit side.

The method for manufacturing a solar cell according to one embodiment of the present invention includes a step of placing a printing plate on one main surface of a photoelectric conversion unit, a conductive paste on the printing plate, and a single squeegee. An electrode pattern having a plurality of finger portions extending in one direction on one main surface and a bus bar portion extending in the other direction intersecting one direction by moving from one side of the direction toward the other side. A step of printing a conductive paste, wherein the printing plate has a first opening corresponding to the finger portion and a second opening corresponding to the bus bar portion, and is more than the second opening of the first opening. The upstream end connected to the second opening of the upstream portion located on one side is from the first main surface opposite to the photoelectric conversion portion of the printing plate to the second main surface on the photoelectric conversion portion side. It has a portion that tapers toward the side.

The printing plate according to one aspect of the present invention is a printing plate for screen printing having a first main surface and a second main surface, the second opening extending in one direction, and the one direction. And a plurality of first openings respectively connected to both ends in the width direction of the second opening, and connected to one end in the width direction of the first opening. The opening has a wider width than the first opening connected to the other end, and the first opening connected to the other end extends from the first main surface side to the second main surface side. It has a tapered part.

According to the present invention, it is possible to provide a method capable of producing a solar cell with high photoelectric conversion efficiency and a printing plate suitably used for the method.

1 is a schematic plan view of a solar cell according to an embodiment of the present invention. It is a schematic side view showing the process of printing an electrode. It is a schematic plan view of a printing plate. FIG. 4 is a schematic plan view in which a portion IV in FIG. 3 is enlarged. FIG. 5 is a schematic cross-sectional view taken along line VV in FIG. 4. FIG. 5 is a schematic cross-sectional view taken along line VI-VI in FIG. 4. FIG. 5 is a schematic cross-sectional view taken along line VII-VII in FIG. 4. It is a typical top view showing the structure of the electrode formed in a comparative example. It is a schematic plan view showing a part of a printing plate according to a first modification. It is a schematic plan view showing a part of a printing plate according to a second modification. It is a schematic sectional drawing showing a part of printing plate concerning the 3rd modification. It is a schematic sectional drawing showing a part of printing plate concerning the 4th modification. It is a schematic sectional drawing showing a part of printing plate concerning the 5th modification. It is a schematic sectional drawing showing a part of printing plate concerning the 6th modification. It is a schematic sectional drawing showing a part of printing plate concerning the 7th modification.

Hereinafter, a preferred embodiment in which the present invention is implemented will be described using the solar cell 1 shown in FIG. 1 as an example. However, the solar cell 1 is merely an example. The present invention is not limited to the solar cell 1 at all.

In each drawing referred to in the embodiment and the like, members having substantially the same function are referred to by the same reference numerals. The drawings referred to in the embodiments and the like are schematically described, and the ratio of the dimensions of the objects drawn in the drawings may be different from the ratio of the dimensions of the actual objects. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

(Configuration of solar cell 1)
As shown in FIG. 1, the solar cell 1 according to this embodiment includes a photoelectric conversion unit 10. The photoelectric conversion unit 10 generates carriers such as electrons and holes by receiving light. The photoelectric conversion unit 10 includes a substrate made of a crystalline semiconductor having a first conductivity type and a semiconductor region having a second conductivity type. The semiconductor region can be formed by introducing a second conductivity type impurity into the substrate. Alternatively, the semiconductor region can be formed by stacking a semiconductor layer containing an impurity of the second conductivity type on the substrate.

The photoelectric conversion unit 10 has a light receiving surface 10a and a back surface 10b. An electrode 11 is disposed on the light receiving surface 10a. Although illustration is omitted, electrodes are similarly arranged on the back surface 10b. The shape of the electrode on the back surface 10b is not particularly limited. The electrode on the back surface 10b may have the same shape as the electrode 11 or may be different. For example, the electrode on the back surface 10b may be formed in a planar shape on substantially the entire back surface 10b. The electrode 11 preferably has a smaller area than the electrode on the back surface 10b in order to reduce light shielding loss.

The material of the electrode is not particularly limited as long as it has conductivity. The electrode can be formed of, for example, a metal such as silver, copper, aluminum, titanium, nickel, or chromium, or an alloy containing one or more of these metals. The electrode may have a plurality of conductive layers.

The electrode 11 has a plurality of finger portions 12 and a plurality of

bus bar portions

13a and 13b. The plurality of finger portions 12 are arranged on substantially the entire light receiving surface 10a in order to collect carriers generated by the photoelectric conversion unit 10 by light reception. Each of the plurality of finger portions 12 has a linear shape extending along the y direction (first direction). The plurality of finger portions 12 are arranged at predetermined intervals along the x direction (second direction) intersecting the y direction. In the solar cell 1, the plurality of finger portions 12 are arranged along the x direction orthogonal to the y direction. The finger portion 12 is made as small as possible in order to reduce the light shielding loss. Specifically, the width of the finger portion 12 (the width in the x direction) is made as small as possible. The width of the finger portion 12 does not have to be constant along the length direction (y direction). For example, the width of the finger portion 12 may be reduced as the distance from the bus bar portion 13a or the bus bar portion 13b increases along the length direction.

The bus bar portion 13 a has a line shape extending along the x direction and is electrically connected to the plurality of finger portions 12. The bus bar portion 13 b also has a line shape extending along the x direction, and is electrically connected to the plurality of finger portions 12. Carriers collected by all of the plurality of finger portions 12 are collected by the bus bar portion 13a and the bus bar portion 13b. The bus bar portion 13a and the bus bar portion 13b have a width (y direction width) larger than that of the finger portion 12 in order to reduce resistance loss.

(Manufacturing method of solar cell 1)
A method for manufacturing the solar cell 1 will now be described.

First, the photoelectric conversion unit 10 is prepared. Next, as illustrated in FIG. 2, the printing plate 20 is disposed on the light receiving surface 10 a of the photoelectric conversion unit 10. The conductive paste 31 is supplied onto the printing plate 20, and the squeegee 30 is moved from the y2 side to the y1 side along the moving direction F, whereby the conductive paste 30 is photoelectrically converted through the opening formed in the printing plate 20. Extrude on top 10. Then, the electrode 11 is formed by hardening the conductive paste 31 extruded on the photoelectric conversion unit 10. Similarly, an electrode is also formed on the back surface 10b. The solar cell 1 is completed by the above.

The conductive paste used for forming the electrode is not particularly limited as long as it contains a conductive material for forming the electrode. The conductive paste may be, for example, a thermosetting paste made of a thermosetting resin in which conductive particles are dispersed, or may be a fired paste. *

Next, the configuration of the printing plate 20 will be used in detail with reference to FIGS.

As shown in FIG. 3, the printing plate 20 has a plurality of first openings 21 and a plurality of

second openings

22a and 22b. The plurality of first openings 21 correspond to the plurality of finger portions 12, and a plurality of linear openings extending along the y direction are formed along the x direction. The second opening 22a has a line shape along the X direction corresponding to the bus bar portion 13a. The second opening 22b has a line shape along the X direction corresponding to the bus bar portion 13b.

The first opening 21 is on the downstream end 21a1 located on the y1 side (downstream in the movement direction F) of the second opening 22a and on the y2 side (upstream in the movement direction F) of the second opening 22a. An upstream end 21b1 positioned, a downstream end 21a2 positioned on the y1 side of the second opening 22b, an upstream end 21b2 positioned on the y2 side of the second opening 22b, and the other portion 21c including. In the printing plate 20, the downstream end portions 21a1, 21a2, the upstream end portions 21b1, 21b2, and the other portions 21c have different shapes. The downstream end 21a1 has the same shape as the downstream end 21a2. The upstream end 21b1 has the same shape as the upstream end 21b2.

Accordingly, FIG. 4 shows the planar shapes of the upstream end 21b1, the downstream end 21a1, and the other portion 21c, and FIG. 4 is used for the planar shapes of the upstream end 21b2 and the downstream end 21a2. . Moreover, the cross-sectional shape of the downstream end 21a1 is shown in FIG. 6, and FIG. 6 is used for the downstream end 21a2. Furthermore, the cross-sectional shape of the upstream end 21b1 is shown in FIG. 7, and FIG. 7 is used for the upstream end 21b2.

FIG. 4 is a schematic top view showing the IV portion of FIG. 3 in an enlarged manner. The second opening 22a has the x direction as the long direction and the y direction as the short direction. The second opening 22a extends in the x direction, and the first opening 22b is connected to both sides in the short direction. Specifically, the downstream end 21a1 of the first opening 22b is connected to the y1 side (one side) of the second opening, and the upstream end 21b1 is connected to the y2 side (the other side). . On the upper surface (first main surface 20a) of the printing plate 20, the downstream end 21a1 has a width W2 substantially equal to the width W1 of the other portion 21c. Further, the upstream end 21b1 has a width W4 that is larger than the width W2 of the downstream end 21a1. The length of the upstream end 21b1 along the y direction is shorter than the length of the downstream end 21a1 along the y direction.

As shown in FIG. 5, the other portion 21 c is formed so that the width is constant in the z direction (the thickness direction of the printing plate 20). That is, in the other portion 21c, the width is W1 in any portion in the z direction.

As shown in Fig. 6, the downstream end 21a1 has a first portion 23 and a second portion 24 in the z direction. The first portion 23 is provided on the first main surface 20 a (upper surface) side of the printing plate 20 opposite to the photoelectric conversion unit 10. The first portion 23 tapers from the first main surface 20a toward the second main surface 20b (lower surface) side on the photoelectric conversion unit 10 side. That is, the width of the first portion 23 decreases from the first main surface 20a toward the second main surface 20b. Specifically, in the printing plate 20, the width of the first portion 23 monotonously decreases from the first main surface 20a toward the second main surface 20b.

The second portion 24 is located closer to the second main surface 20b than the first portion 23 is. In the present embodiment, the second portion 24 extends from the tip of the first portion 23 on the second main surface 20b side to the second main surface 20b. The width of the second portion 24 is constant in the z direction. The width of the second portion 24 is substantially equal to the width at the tip of the first portion 23 on the second main surface 20b side. For this reason, the opening area of the second portion 24 is substantially equal to the opening area at the tip of the first portion 23 on the second main surface 20b side.

The length of the first portion 23 along the z direction is preferably 0.1 to 0.6 times the thickness of the printing plate 20. The length of the second portion 24 along the z direction is preferably 0.4 to 0.9 times the thickness of the printing plate 20. The length of the second portion 24 along the z direction is preferably 0.8 to 1.0 times the length of the first portion 23 along the z direction.

As shown in Fig. 7, the upstream end 21b1 has a portion that tapers from the first main surface 20a side toward the second main surface 20b side. In the printing plate 20, the entire upstream end 21b1 tapers from the first main surface 20a toward the second main surface 20b. That is, the width of the upstream end 21b1 decreases from the first main surface 20a toward the second main surface 20b. The width at the first main surface 20a of the upstream end 21b1 is smaller than the width at the second main surface 20b. The width W5 of the second main surface 20b of the upstream end 21b1 is substantially equal to the width W1 of the other portion 21c.

Incidentally, the electrodes are usually printed by using a printing plate in which the width of the first opening 21 is constant in the y direction and the z direction. However, in this case, the amount of paste passing through each of the upstream end and the downstream end of the first opening is different from the amount of paste passing through the other portions. Specifically, the amount of paste passing through the downstream end immediately after passing through the second opening is greater than the amount of paste passing through other portions. Further, the amount of paste passing through the downstream end increases as it approaches the second opening. On the other hand, the passage amount of the paste at the upstream end is smaller than the passage amount of the paste at the other portions. Further, the amount of paste passing through the upstream end portion decreases as the second opening is approached. Therefore, as shown in FIG. 8, the width of the portion 112b1 located on the upstream side of the bus bar portion of the finger portion 112 becomes narrower as it approaches the bus bar portion, while located on the downstream side of the bus bar portion. The width of the portion 112a1 becomes thicker as it approaches the bus bar portion. Accordingly, the finger portions cannot be formed with a uniform width and high accuracy.

Therefore, in Patent Document 1, by making the opening width at the upstream end of the printing plate wider than the opening width at the downstream end, the amount of paste passing through the upstream end is increased, and the paste at the downstream end is increased. Trying to reduce the amount of passage. However, simply reducing the opening width at the downstream end portion makes it difficult for the conductive paste that has entered the opening to come off, and this portion may cause printing scraping or disconnection. For this reason, it is difficult to sufficiently reduce the width of the finger portion at the position corresponding to the downstream end portion. Further, if the opening width at the upstream end is simply widened, the conductive paste is likely to bleed on the photoelectric conversion portion and may spread undesirably. Also in this case, it is difficult to sufficiently reduce the width of the finger portion at the position corresponding to the upstream end portion.

On the other hand, in the printing plate 20, the downstream end 21a1 has a first portion 23 that becomes narrower from the first main surface 20a toward the second main surface 20b, and a second portion that has a small opening area. Part 24. For this reason, the amount of paste passing through the downstream end 21a1 can be reduced by making the second portion 24 thinner. Further, since the length in the Z direction of the second portion, which is narrow, is smaller than the length in the Z direction of the printing plate 20, the paste is easily removed. Therefore, the width | variety of the finger part of the part corresponding to the downstream end part 21a1 can be made smaller than before. For this reason, by using the printing plate 20, even if the finger portion 12 is thin, the finger portion 12 can be formed with high shape accuracy.

In the present embodiment, the upstream end 21b1 has a width W4 on the first main surface 20a of the upstream end 21b1 larger than the width W1 of the other portion 21c, and the first end of the upstream end 21b1. The width of the main surface 20a is smaller than the width of the second main surface 20b. For this reason, the passage amount of the paste at the upstream end 21b1 is increased. Further, the width W5 of the second main surface 20b of the upstream end 21b1 is smaller than W4. Therefore, the amount of paste that is pushed out to the photoelectric conversion unit side is restricted, and bleeding is unlikely to occur. For this reason, the width | variety of the finger part 12 of the position corresponding to the upstream edge part 21b1 can be made small enough. Therefore, the finger part 12 can be formed with higher shape accuracy.

Therefore, by forming the electrode 11 using the printing plate 20, the width of the finger portion 12 can be reduced, so that the light shielding loss due to the finger portion 12 can be reduced. For this reason, the solar cell with improved photoelectric conversion characteristics can be manufactured.

It should be noted that the length of the upstream connection portion with respect to the bus bar portion of the finger portion, which tends to be narrow, is shorter than the length of the downstream connection portion with respect to the bus bar portion of the finger portion, which tends to be wide. For this reason, it is preferable that the length of the upstream end 21b1 is shorter than the length of the downstream end 21a1.

Hereinafter, modifications of the above embodiment will be described. In the following description, members having substantially the same functions as those of the above embodiment are referred to by the same reference numerals, and description thereof is omitted.

The features described in the following first to seventh modifications may be implemented alone or in combination of two or more. For example, the solar cell may satisfy both the characteristics of the first modification and the characteristics of the second modification.

(First modification)
In the above embodiment, the case where the width W2 of the first main surface 20a of the downstream end 21a1 is equal to the width W1 of the other portion 21c has been described. However, as shown in FIG. May be narrowed. By doing so, it can suppress more effectively that the width | variety of the upstream connection part with respect to the bus-bar part of a finger part becomes thick.

(Second modification)
In the above-described embodiment, the example in which the width is constant in the y direction at each of the upstream end portions 21b1 and 21b2 and the downstream end portions 21a1 and 21a2 has been described. However, the present invention is not limited to this configuration. For example, as shown in FIG. 10, the width W2 at the downstream end portions 21a1, 21a2 may be narrowed toward the

second openings

22a, 22b. By doing so, the width | variety of the upstream connection part with respect to the bus-bar part of a finger part can be made more uniform.

Further, the width W4 at the upstream end portions 21b1 and 21b2 may be increased toward the

second openings

22a and 22b. By doing so, the width | variety of the downstream connection part with respect to the bus-bar part of a finger part can be made more uniform.

(Third Modification)
In the above embodiment, the example in which the length in the z direction of the second portion 24 is constant in the y direction has been described. However, the present invention is not limited to this configuration. For example, as shown in FIG. 11, the length in the z direction of the second portion 24 may be increased toward the

second openings

22a and 22b. By doing so, the width | variety of the upstream connection part with respect to the bus-bar part of a finger part can be made more uniform.

(Fourth modification)
In the above-described embodiment, the example in which the entire upstream end portions 21b1 and 21b2 are formed in a tapered shape toward the second main surface 20b side in the z direction has been described. However, the present invention is not limited to this configuration. For example, as shown in FIG. 12, the upstream end portions 21b1 and 21b2 also include a first portion 23 that tapers toward the second main surface 20b side and a second portion 24 that has a constant width. You may have.

(Fifth modification)
In the above embodiment, an example in which the downstream end portions 21a1 and 21a2 are configured by the first and

second portions

23 and 24 has been described. However, the present invention is not limited to this configuration. For example, as shown in FIG. 13, even if a third portion 25 that is wider toward the second main surface 20 b side than the second portion 24 is provided on the second main surface 20 b side. Good.

(6th and 7th modification)
In the above-described embodiment, the example in which the width of the first portion 23 of the downstream end portions 21a1 and 21a2 is linearly narrowed toward the second main surface 20b side has been described. However, the present invention is not limited to this configuration. For example, as shown in FIGS. 14 and 15, the width of the first portion 23 of the downstream end portions 21a1 and 21a2 may be narrowed in a high-order function toward the second main surface 20b. Good.

In the above embodiment, an example in which each of the

bus bar portions

13a and 13b is linear has been described. However, in the present invention, the bus bar portion does not necessarily have to be linear. The bus bar portion may be formed in a zigzag shape, for example. *

In the above embodiment, the upstream end 21b1 is tapered toward the second main surface 20b. However, the upstream end is the same as the portion other than the upstream end and the downstream end. In addition, the width may be uniform in the z direction. *

In the above embodiment, the example in which the width W2 of the first main surface 20a of the first portion 23 is equal to the width W1 of the other portion 21c has been described, but the width W2 may be larger than the width W1. Even in such a case, since the second portion 24 is provided, it is possible to suppress an excessive amount of paste passing through the downstream end 21a1.

In the above-described embodiment, the example in which the width of the other portion 21c is constant in the z direction has been described, but the present invention is not limited to this.

Moreover, although the said embodiment demonstrated the example which forms the electrode which has a finger part whose width | variety is constant in ay direction, the taper-shaped finger part which becomes narrow as it leaves | separates from a bus-bar part, and the finger of other shapes The present invention can also be applied when forming an electrode having a portion. In this case, what is necessary is just to adjust suitably the planar shape of an upstream edge part and a downstream edge part corresponding to the planar shape of a finger part.

DESCRIPTION OF SYMBOLS 1 ... Solar cell, 10 ... Photoelectric conversion part, 10a ... Light-receiving surface, 10b ... Back surface, 11 ... Electrode, 12 ... Finger part, 13a, 13b ... Bus-bar part, 20 ... Printing plate, 20a ... 1st main surface, 20b 2nd main surface, 21 ... 1st opening, 21a1, 21a2 ... Downstream end, 21b1, 21b2 ... Upstream end, 22a, 22b ... 2nd opening, 23 ... 1st part, 24 ... 2nd part, 25 ... 3rd part, 30 ... Squeegee, 31 ... Conductive paste

Claims

Arranging a printing plate on one main surface of the photoelectric conversion unit;
A plurality of finger portions extending in the one direction on the one main surface by supplying a conductive paste on the printing plate and moving the squeegee from one side to the other side in the one direction. Printing the conductive paste on a pattern of electrodes having a bus bar portion extending in the other direction intersecting the one direction,
The printing plate has a first opening corresponding to the finger portion and a second opening corresponding to the bus bar portion,
The downstream end connected to the second opening of the downstream portion located on the other side of the second opening of the first opening is opposite to the photoelectric conversion unit of the printing plate A first portion that tapers from the first main surface toward the second main surface on the photoelectric conversion portion side, and is positioned closer to the photoelectric conversion portion than the first portion, And a second part having an opening area equal to the opening area at the tip of the one part on the photoelectric conversion part side.
It is a manufacturing method of the solar cell of Claim 1, Comprising:
The width of the downstream end portion on the first main surface is equal to the width of the downstream main portion other than the downstream end portion on the first main surface.
It is a manufacturing method of the solar cell of Claim 1, Comprising:
The width at the first main surface of the downstream end is narrower than the width at the first main surface of the portion other than the downstream end of the downstream portion.
It is a manufacturing method of the solar cell of Claim 3, Comprising:
The width of the downstream end portion on the first main surface becomes narrower toward the second opening side.
A method for producing a solar cell according to any one of claims 1 to 4,
The length in the thickness direction of the second portion becomes longer as it goes to the second opening side.
A method for producing a solar cell according to any one of claims 1 to 5,
The length in the thickness direction of the second portion is in the range of 0.1 to 0.6 times the length in the thickness direction of the printing plate.
A method for producing a solar cell according to any one of claims 1 to 6,
The upstream end connected to the second opening of the upstream portion located on one side of the second opening of the first opening is connected to the second main surface from the first main surface side. A width at the first main surface of the upstream end portion is a width at the first main surface of the portion other than the upstream end portion of the upstream portion. Bigger than.
It is a manufacturing method of the solar cell according to claim 7,
The width of the upstream end portion on the first main surface becomes wider toward the second opening side.
A method for producing a solar cell according to claim 7 or 8,
The length of the downstream portion along the one direction is longer than the length of the upstream end portion along the one direction.
Arranging a printing plate on one main surface of the photoelectric conversion unit;
A plurality of finger portions extending in the one direction on the one main surface by supplying a conductive paste on the printing plate and moving the squeegee from one side to the other side in the one direction. Printing the conductive paste on a pattern of electrodes having a bus bar portion extending in the other direction intersecting the one direction,
The printing plate has a first opening corresponding to the finger portion and a second opening corresponding to the bus bar portion,
An upstream end connected to the second opening of the upstream portion located on the one side of the second opening of the first opening is opposite to the photoelectric conversion unit of the printing plate The manufacturing method of a solar cell which has a part which tapers toward the 2nd main surface side by the side of the said photoelectric conversion part from the 1st main surface.
It is a manufacturing method of the solar cell according to claim 10,
The width of the upstream end portion on the first main surface is larger than the width of the upstream main portion other than the upstream end portion on the first main surface.
A printing plate for screen printing having a first main surface and a second main surface,
A second opening extending in one direction;
A plurality of first openings extending in the other direction intersecting the one direction and connected to both ends in the width direction of the second opening,
The first opening connected to one end in the width direction of the first opening has a width wider than the first opening connected to the other end,
The first opening connected to the one end has a portion that tapers from the first main surface side toward the second main surface side.
A printing plate for screen printing having a first main surface and a second main surface,
A second opening extending in one direction;
A plurality of first openings extending in the other direction intersecting the one direction and connected to both ends in the width direction of the second opening,
The first opening connected to one end in the width direction of the first opening has a width wider than the first opening connected to the other end,
The first opening connected to the other end includes a first portion that tapers from the first main surface toward the second main surface, and the second main portion than the first portion. And a second portion that is located on the surface side and has an opening area equal to the opening area at the tip of the first portion on the second main surface side of the first portion.
A printing plate for screen printing according to claim 13,
The first opening connected to the one end has a portion that tapers from the first main surface side toward the second main surface side.