JP2013220599A - Method of manufacturing solar battery element, and screen printing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a solar battery element, in which an electrode can be efficiently formed by a screen printing method.SOLUTION: There is provided a method of manufacturing a solar battery element in which an electrode is formed by screen printing of a conductive paste on a substrate for the solar battery element by using a screen printing machine including: a scraper for coating a screen plate with the paste; and a squeegee for printing the paste, with which the screen plate is coated, by pushing the paste out of an opening part of the screen plate to printed matter therebelow while moving with its tip part pressing the screen plate; wherein the squeegee 9 has a plurality of projection parts 14 and/or recessed parts 15 restricting flowing of the paste, while arranged on a line at predetermined intervals in the squeegee length direction, in a region coming into contact with the paste during printing on a printing movement-directional front surface (paste scraping-out surface 9a) of the squeegee 9.

Description

  The present invention relates to a method for manufacturing a solar cell element for forming electrodes by a screen printing method and a screen printer for forming electrodes for solar cell elements.

  In general, a solar cell element has a structure shown in FIG. In FIG. 1, 1 is a plate shape having a size of 100 to 150 mm square and a thickness of 0.1 to 0.3 mm, and is made of polycrystal, single crystal silicon or the like, and doped with p-type impurities such as boron. It is a p-type semiconductor substrate.

  In manufacturing a solar cell element, an n-type diffusion layer 2 is formed by doping an n-type impurity such as phosphorus on the semiconductor substrate 1 and an antireflection film / passivation film 3 made of SiN (silicon nitride) is provided. Then, after a conductive aluminum paste is printed on the back surface using a screen printing method, the back electrode 6 and the BSF (Back Surface Field) layer 4 are simultaneously formed by drying and firing. Further, after printing the conductive paste on the surface, it is dried and fired to form the surface electrode 5.

  The surface electrode 5 includes a bus bar electrode for taking out a photo-generated current generated in the solar cell element to the outside, and a finger electrode for collecting current connected to the bus bar electrode. Hereinafter, the surface of the substrate that is the light receiving surface side of the solar cell element is the front surface (front surface), and the surface of the substrate that is opposite to the light receiving surface side is the back surface (back surface).

  In a solar cell element manufactured by such a method, it is common to use a screen printing method for electrode formation as described above. The screen printing method is suitable for mass production of a thick film electrode with a high yield as compared with a photolithography method using a photosensitive material, and has an advantage that the equipment cost is relatively low. Therefore, the screen printing method includes not only the formation of electrodes for solar cell elements, but also the formation of patterns such as electrode layers, resistor layers, dielectric layers, or phosphor layers of large area displays such as plasma display panels and liquid crystal display panels. Widely used in the industry.

A conventional screen printing method will be described with reference to the drawings. FIG. 2 is a schematic side view of the main part of a general screen printing machine, and FIG. 3 is a schematic plan view of the movement of the paste by a general screen printing method as seen from above the screen plate. A series of printing operations relating to screen printing will be described with reference to FIG.
First, a paste is supplied onto the screen plate 7 in which a pattern to be formed is opened (the paste is not shown in FIG. 2). Next, on the paste, the scraper 8 moves in a certain direction (leftward in FIG. 2) while pressure is applied from above, thereby filling the paste in the pattern of the openings of the screen plate 7. Next, the scraper 8 is raised, the squeegee 99 is lowered, and the tip thereof presses the screen plate 7 toward the printing stage 10. Next, in this pressed state, the squeegee 99 moves in the direction opposite to the moving direction of the scraper 8 (rightward in FIG. 2), so that the paste filled in the pattern of the opening of the screen plate 7 is placed on the printing stage 10. The image is transferred to the substrate 11 placed on the printer. Subsequently, the squeegee 99 is raised, the scraper 8 is lowered and comes into contact with the surface of the screen plate 7, and the scraper 8 remains on the screen plate 7 while moving in a direction opposite to the moving direction of the squeegee 99. The paste is again filled into the pattern of the openings of the screen plate 7. In the screen printing machine, a predetermined pattern of paste is thickly applied to the substrate 11 by repeating the above series of operations.

  The conventional screen printing method will be described in more detail with reference to FIG. FIG. 3A shows a state before the squeegee 99 is disposed at a position where the paste 12 of the screen plate 7 is filled and the screen plate 7 is pressed and moved. The squeegee 99 presses the screen plate 7 from this position, moves downward in FIG. 3, transfers the paste to the printing portion under the screen plate 7 and prints it. At this time, the paste 12 existing on the screen plate 7 on the moving direction side of the squeegee 99 is scraped to the front surface (scraping surface) in the moving direction of the squeegee 99 and moves together with the squeegee 99.

  FIG. 3B shows a state immediately after the movement of the squeegee 99 is completed and printing is completed. At this time, as shown in FIG. 3B, a part of the paste 12 flows on the scraped surface of the squeegee 99 and protrudes from both ends of the squeegee 99, and becomes the protruding paste 13 on the screen plate 7. . Since this protruding paste 13 is outside the operating range of the squeegee 99 and the scraper 8, it will not be used for subsequent printing.

  As described above, in the conventional screen printing method, a part of the supplied paste protrudes and remains at both ends of the squeegee after the squeegee operation. On the other hand, there is a problem in that the paste that can be transferred and printed is reduced, and the printing portion on the printed material is faded, resulting in poor printing. In order to prevent this printing defect, conventionally, it is necessary to collect the paste protruding by the operator by scraping it to the center, or to supply the paste more than the necessary amount. It was a problem in terms of production cost.

  In order to solve this problem, for example, in the method disclosed in Japanese Patent Application Laid-Open No. 5-77393 (Patent Document 1), printing is performed by providing eight-shaped auxiliary scrapers at both ends of the side surface of the squeegee on the scraper side. Is disclosed. However, this method requires the control of the auxiliary scraper and has a problem that the control of the printing conditions becomes complicated.

JP-A-5-77393

  The present invention has been made in view of the above circumstances, and a method for manufacturing a solar cell element capable of efficiently performing electrode formation by a screen printing method, and a solar that suppresses protrusion of paste from a printing area of a screen plate. It aims at providing the screen printer for electrode formation of a battery element.

In order to achieve the above object, the present invention provides the following solar cell element manufacturing method and screen printer.
[1] A scraper for coating the screen plate with a paste, and the paste coated on the screen plate while the tip moves while pressing the screen plate, from the opening of the screen plate to the substrate to be printed A method for manufacturing a solar cell element, wherein an electrode is formed by screen-printing a conductive paste on a substrate for a solar cell element using a screen printer provided with a squeegee for extruding and printing, the squeegee comprising the squeegee A plurality of convex portions and / or concave portions for regulating the flow of the paste arranged in a line at a predetermined interval in the squeegee length direction in a region in contact with the paste at the time of printing on the front surface in the printing movement direction. A method for producing a solar cell element.
[2] The substrate for the solar cell element is obtained by forming a diffusion layer on a semiconductor substrate and forming an antireflection film thereon, and using the screen printer on the antireflection film, the conductive layer is made conductive. The method for producing a solar cell element according to [1], wherein the electrode is formed by screen printing a paste.
[3] The method for manufacturing a solar cell element according to [1] or [2], wherein the plurality of convex portions and concave portions are alternately arranged on a front surface of the squeegee in the printing movement direction.
[4] The method for producing a solar cell element according to any one of [1] to [3], wherein an adjacent interval between adjacent convex portions and / or concave portions is 1 to 100 mm.
[5] The solar cell according to any one of [1] to [4], wherein the plurality of convex portions and / or concave portions are arranged in parallel to an outer edge of the tip portion of the squeegee. Device manufacturing method.
[6] The method for manufacturing a solar cell element according to any one of [1] to [5], wherein the convex portion has a cylindrical shape.
[7] The method for manufacturing a solar cell element according to any one of [1] to [6], wherein the concave portion is a round hole.
[8] A scraper for coating the screen plate with the paste, and the paste coated on the screen plate while moving with the tip portion pressed against the screen plate, from the opening of the screen plate to the printed material under the screen plate A screen printing machine having a squeegee for extruding and printing, wherein the squeegee is in front of the squeegee in the printing movement direction and is in a region in contact with the paste during printing, and a plurality of protrusions for restricting the flow of the paste and / or Alternatively, a screen printing machine for forming an electrode of a solar cell element, having concave portions arranged in a line at predetermined intervals in the squeegee length direction.

  According to the method for manufacturing a solar cell element of the present invention, it is possible to reduce the trouble of scraping the paste protruding from the operator to the center part when forming an electrode by the screen printing method, and to improve the production efficiency of the solar cell element. Can do. Further, according to the screen printing machine of the present invention, since the convex portion and / or the concave portion are provided on the front surface (paste scraping surface) in the printing movement direction of the squeegee to restrict the flow of the paste that tries to protrude from both ends of the squeegee, It is possible to reduce the trouble of scraping off the paste that has protruded to the center, and when used in combination with the paste supply device, it is possible to perform unattended operation for a long time, and it is easy to set printing conditions.

It is sectional drawing which shows the structural example of a solar cell element. It is sectional drawing which shows schematic structure of the conventional screen printer. It is a schematic diagram which shows the state of the paste at the time of screen printing by the screen printer of FIG. 2, (a) is the state at the time of printing start, (b) is the state at the time of completion | finish of printing. It is sectional drawing which shows schematic structure of the screen printer concerning this invention. It is a perspective view which shows the structure of the squeegee used with the screen printer which concerns on this invention, (a) is a 1st structural example, (b) is a 2nd structural example. It is a schematic diagram which shows the state of the paste at the time of screen printing by the screen printer of FIG. 4, (a) is the state at the time of printing start, (b) is the state at the time of completion | finish of printing.

  Hereinafter, embodiments of the present invention will be described in detail. The present invention can be implemented in a wide variety of other embodiments in addition to the following description, and the scope of the present invention is not limited to the following, but is described in the claims. is there. Further, the drawings are not shown to scale. In order to make the explanation and understanding of the present invention clearer, dimensions are enlarged depending on related members, and unimportant parts are not shown.

Here, taking the solar cell element having the general structure shown in FIG. 1 as an example, the manufacturing process will be described.
(Preparation of semiconductor substrate)
First, the semiconductor substrate 1 is prepared. The semiconductor substrate 1 is made of single crystal or polycrystalline silicon, and may be either p-type or n-type, but includes p-type semiconductor impurities such as boron, and has a specific resistance of 0.1 to 4.0 Ω · cm. A p-type silicon substrate is often used. Therefore, hereinafter, a method for manufacturing a solar cell element using a p-type silicon substrate will be described as an example.

  A semiconductor substrate (also referred to as a silicon substrate) 1 having a plate shape of 100 to 150 mm square and a thickness of 0.05 to 0.30 mm is preferably used. Then, the surface of the p-type silicon substrate serving as the light-receiving surface of the solar cell element is immersed in an acidic solution, for example, to remove surface damage caused by slicing, etc., and further cleaned and dried by chemical etching with an alkaline solution. Thus, an uneven structure called a texture is formed. The concavo-convex structure causes multiple reflection of light on the light receiving surface of the solar cell element. Therefore, by forming the concavo-convex structure, the reflectance is effectively reduced and the conversion efficiency is improved.

(Diffusion layer formation)
Thereafter, a thermal diffusion method in which the p-type semiconductor substrate 1 is placed in a high-temperature gas at 850 to 1,000 ° C. containing, for example, POCl ₃ , and an n-type impurity element such as phosphorus is diffused over the entire surface of the p-type semiconductor substrate 1. Thus, the n-type diffusion layer 2 having a sheet resistance of about 30 to 300 Ω / □ is formed on the front surface of the semiconductor substrate 1. Note that when the n-type diffusion layer 2 is formed by a thermal diffusion method, n-type diffusion layers may be formed on both surfaces and end surfaces of the p-type semiconductor substrate 1. An unnecessary n-type diffusion layer can be removed by immersing the p-type semiconductor substrate 1 whose front surface of the type diffusion layer is covered with an acid-resistant resin in a hydrofluoric acid solution. Thereafter, the glass layer formed on the surface of the semiconductor substrate at the time of diffusion is removed by immersing in a chemical such as a diluted hydrofluoric acid solution, and washed with pure water.

(Formation of antireflection film and passivation film)
Further, an antireflection film / passivation film 3 is formed on the front side of the p-type semiconductor substrate 1. The anti-reflection film / passivation film 3 is made of, for example, SiN, and is formed by, for example, a plasma CVD method in which a mixed gas of SiH ₄ and NH ₃ is diluted with N ₂ , and plasma is deposited by glow discharge decomposition. The This antireflection film / passivation film 3 is formed so as to have a refractive index of about 1.8 to 2.3 in consideration of a difference in refractive index with respect to the p-type semiconductor substrate 1, and has a thickness of 500 to 1,000 mm. The p-type semiconductor substrate 1 is formed to have a thickness of about 80 mm and is provided to prevent light from being reflected from the surface of the p-type semiconductor substrate 1 and to effectively incorporate light into the p-type semiconductor substrate 1. The antireflection film (SiN film) also functions as a passivation film having a passivation effect on the n-type diffusion layer 2 when formed, and improves the electrical characteristics of the solar cell element together with the antireflection function. There is an effect to make.

(Formation of BSF layer and front and back electrodes)
Next, a conductive paste containing, for example, aluminum, glass frit, varnish and the like is screen printed on the back surface of the semiconductor substrate 1 and dried. Thereafter, a charging paste containing, for example, silver, glass frit and varnish is screen-printed on the front side and dried. Thereafter, the BSF layer 4, the front electrode 5, and the back electrode 6 are formed by firing each electrode paste at a temperature of about 500 to 950 ° C.

  In a typical method for manufacturing a crystalline silicon solar cell element as described above, electrodes are formed by screen printing. In the conventional screen printing method, as described above with reference to FIGS. 2 and 3, a part of the supplied paste 12 protrudes from both ends of the squeegee 99 and remains on the screen plate 7 after the squeegee operation. As the number of times of printing increases, the paste that is no longer used increases, but the paste that can be transferred and printed decreases, the electrode pattern on the semiconductor substrate becomes faint, resulting in poor printing, and the yield decreases. In order to prevent this printing defect, conventionally, it is necessary to collect the paste protruding from the operator by scraping it to the center, or to supply the paste in more than the necessary amount. It was a problem.

  In order to solve this problem, the present inventors diligently studied on the squeegee and have come to achieve the present invention. That is, as shown in FIG. 4, the screen printing machine according to the present invention has a scraper 8 that coats the screen plate 7 with a paste, and the screen plate 7 moves while the tip portion presses the screen plate 7 while moving. The screen printing machine includes a squeegee 9 for extruding and printing the paste coated on the substrate 11 under the screen plate 7 for printing, the squeegee 9 being in front of the printing movement direction of the squeegee 9 (paste scraping surface). In FIG. 4, a plurality of convex portions and / or concave portions (protruding portions 14 in FIG. 4) that regulate the flow of the paste are arranged in a line at predetermined intervals in the squeegee length direction in the region that contacts the paste during printing. It is characterized by having. The squeegee length direction is a direction perpendicular to the printing movement direction of the squeegee.

  Here, the shape of the squeegee 9 may be any of a flat squeegee, a square squeegee, a sword squeegee, a tip cut squeegee, but is not limited thereto.

  The main material of the squeegee 9 is preferably an elastic material such as urethane rubber, but a metal material may be used and is not limited thereto. The hardness of the squeegee 9 made of an elastic material is preferably 60 to 95 degrees in terms of JIS A hardness, but is not limited to this range.

The size of the squeegee 9 may be, for example, a thickness of 3.0 to 10.0 mm, a width of 10 to 100 mm, and a length of 50 to 2000 mm (the shape (thickness, width, length) of the squeegee 9 is For example, when printing an electrode pattern on a square plate-like semiconductor substrate 1 having a side of 15 cm, a squeegee having a thickness of 6.0 mm, a width of 50 mm, and a length of 200 mm is preferable. Used for.
The squeegee used here can also be used as a scraper.

  In the present invention, the substrate 11 is a substrate for a solar cell element, and the surface of the substrate that is subjected to screen printing for electrode formation is the antireflection film / passivation film 3 described above. It is a surface of a semiconductor substrate on which no antireflection film or a diffusion layer is formed.

FIG. 5 is a perspective view showing a structural example of the squeegee in the embodiment of the present invention. Here, a flat squeegee will be described as an example.
As shown in FIG. 5 (a), the squeegee 9 has a plurality of protrusions 14 at a predetermined interval in the squeegee length direction on a paste scraping surface (front surface in the printing movement direction) 9a for printing paste on the screen plate 7. They are arranged in a line. Moreover, the convex part 14 is arrange | positioned in the area | region which contacts a paste in the case of printing in the paste scraping surface 9a.

  Further, the shape of the convex portion 14 may be any shape such as a round shape, a polygonal shape, or a corrugated shape as long as it protrudes from the paste scraping surface 9a. As shown in FIG. It's okay. Furthermore, the magnitude | size of the convex part 14 may be arbitrary magnitude | sizes in the range which can provide the several convex part 14 in the paste scraping surface 9a at a fixed space | interval. Moreover, 1-100 mm is preferable and, as for the adjacent space | interval of the convex parts 14, 10-50 mm is more preferable. If the distance between adjacent protrusions 14 is less than 1 mm, the paste going back on the paste scraping surface 9 a may not pass between the protrusions 14, and if it exceeds 100 mm, the paste flow suppression effect may be insufficient.

Further, the plurality of convex portions 14 are preferably arranged in parallel to the outer edge of the tip portion of the squeegee 9 (tip portion that presses the screen plate 7). Thereby, the flow of the paste can be efficiently and uniformly suppressed.
In addition, this convex part 14 may be similarly formed in the surface opposite to the paste scraping surface 9a for printing paste.

  When such a squeegee 9 is used, the paste scraped out by the squeegee 9 during printing tends to flow on the paste scraping surface 9a but is easily entangled with the convex portion 14, and the flow is regulated. . At this time, since the convex portions 14 are arranged in a state of being spaced apart at a certain interval, it is not completely limited that the paste goes back up the paste scraping surface 9a. Passes between the convex portions 14, goes up the paste scraping surface 9 a, flows slightly in the squeegee length direction, and then descends again to the screen plate 7 side, so the paste to the screen plate 7 in the length direction of the squeegee 9 The supply amount can be made uniform. Accordingly, as compared with the case where the conventional squeegee 99 without the convex portion 14 is used, the paste is likely to remain on the squeegee surface (paste scraping surface 9a), and the paste is difficult to protrude from both ends of the squeegee. The paste is evenly supplied to 7 and the blurring of partial printing is suppressed. Furthermore, the paste utilization efficiency at the time of printing is improved, and an increase in paste coating amount can be expected. Further, the printing conditions when using the squeegee 9 need not be changed from the printing conditions when using the existing squeegee 99.

  In this way, by using the squeegee 9, in the solar cell element manufacturing process, in the electrode forming process by the screen printing method, the operator has to scrape the paste protruding from the screen printing area to the center of the printing area. Thus, the paste can be used effectively. For example, if it is used in combination with a paste supply device, it can be operated unattended for a long time. Further, the screen printing machine can perform screen printing with an increased paste coating amount and easy setting of printing conditions.

  Further, the squeegee 9 used in the present invention is not limited to the structure shown in FIG. 5A, and may have a structure shown in FIG. 5B, for example. In FIG. 5B, the squeegee 9 is provided with a plurality of convex portions 14 and concave portions 15 alternately arranged in a line at predetermined intervals in the squeegee length direction on the paste scraping surface (front surface in the printing movement direction) 9a. . Thereby, it becomes possible to leave more paste uniformly on the entire paste scraping surface 9a of the squeegee 9.

  The shape of the recess 15 may be any shape such as a round shape, a polygonal shape, or a corrugated shape in the opening as long as it is recessed from the paste scraping surface 9a, and may be a round hole as shown in FIG.

  Moreover, it is preferable that the adjacent space | interval of adjacent convex parts 14 and recessed parts 15 is 1-100 mm, and 10-50 mm is more preferable. If the distance between the two is less than 1 mm, the paste going back on the paste scraping surface 9a may not pass between the convex portion 14 and the concave portion 15, and if it exceeds 100 mm, the paste flow suppression effect may be insufficient. .

  As described above, by forming the plurality of convex portions 14 and / or concave portions 15 in a predetermined arrangement pattern on the paste scraping surface (print movement direction front surface) 9a of the squeegee 9, it is possible to improve the use efficiency of the paste.

  Note that the squeegee 9 need not be the only target for forming the convex portions 14 and the concave portions 15, and is in contact with the paste during screen printing, and if it remains as it is, the paste flows in the contact region and protrudes from the printing region. It may be a place. For example, in a screen printing machine, the same may be applied to an aspect in which a cover formed with a convex portion 14 and / or a concave portion 15 is attached to a clamp portion that fixes a squeegee so as to be disposed on the front side in the printing movement direction of the squeegee 9. Can be expected. According to this, the cover formed with the convex portions 14 and / or the concave portions 15 comes into contact with the remaining paste at the time of screen printing, so that the paste is likely to remain on the cover surface and the paste does not easily protrude from the end portion. In addition, the paste use efficiency during printing is increased, and the amount of paste applied can be expected to increase. In addition, you may use together the cover in which this convex part 14 and / or the recessed part 15 were formed, and the squeegee 9 in which the convex part 14 and / or the recessed part 15 were formed.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these.

[Example 1]
First, by performing outer diameter processing on a p-type silicon substrate made of p-type single crystal silicon doped with boron and sliced to a thickness of 0.2 mm and having a specific resistance of about 1 Ω · cm, a side of 15 cm is formed. A square plate was used. Then, this p-type silicon substrate was immersed in a hydrofluoric acid solution for 15 seconds for damage etching, and further chemically etched with a 70 ° C. solution containing 2% by mass of KOH and 2% by mass of IPA (isopropyl alcohol) for 5 minutes. Later, by washing with pure water and drying, a texture structure was formed on the surface of the p-type silicon substrate.

A diffusion layer (n layer) was formed on the p-type silicon substrate by subjecting the p-type silicon substrate to thermal diffusion treatment in a POCl ₃ gas atmosphere at a temperature of 850 ° C. for 30 minutes. The sheet resistance after heat treatment of the surface of the p-type silicon substrate prepared here was about 80Ω / □ on one side, and the diffusion depth of the n layer was 0.3 μm.

Thereafter, after forming an acid resistant resin on the n layer, the p-type silicon substrate was immersed in a hydrofluoric acid solution for 10 seconds to remove the portion of the n layer where the acid resistant resin was not formed. Thereafter, the acid-resistant resin was removed to form an n layer only on the surface of the p-type silicon substrate. Subsequently, SiN serving as an antireflection film and a passivation film is formed on the surface of the p-type silicon substrate on which the n layer is formed by plasma CVD using SiH ₄ , NH ₃ , and N _2. Formed with.
Next, a conductive aluminum paste was printed on the back surface of the p-type silicon substrate using a screen printing method and dried at 150 ° C. Next, a conductive silver paste was printed on the front surface of the p-type silicon substrate using a screen printing method and dried at 150 ° C. to form finger electrodes. Furthermore, a conductive silver paste was printed on the bus bar electrode using a screen printing method so as to be orthogonal to these finger electrodes, and dried at 150 ° C.
In the screen printing method at this time, a screen printing machine having the configuration shown in FIG. 4 was used. The configuration of the squeegee 9 has a thickness of 6.0 mm, a width of 50 mm, and a length of 200 mm as shown in FIG. 5B, and the convex portion 14 has a cylindrical shape with a diameter of 0.5 mm and a height of 0.5 mm. The recess 15 is a round hole having a diameter of 0.5 mm and a depth of 0.5 mm.
Finally, the solar cell element was produced by baking an electrically conductive paste from the processed substrate so far at a maximum temperature of 800 ° C. to form an electrode.

[Comparative Example 1]
In Example 1, the squeegee used for conductive paste printing by the screen printing method was replaced with a general flat squeegee (that is, the configuration shown in FIG. 2), and a solar cell element was manufactured under the conditions of Example 1 except that. .

As described above, 1,000 solar cell elements were produced under the conditions of Example 1 and Comparative Example 1, respectively, and the processing tact per solar substrate in the screen printing process of the conductive paste at that time, the solar cell The appearance inspection pass rate of the element and the average conversion efficiency of the solar cell element were determined. In addition, the external appearance inspection of the solar cell element is to visually inspect for the presence or absence of an electrode defect, and the ratio that passed the visual inspection was defined as the appearance inspection pass rate. Moreover, the conversion efficiency of the solar cell element was determined by measuring the electric characteristics of the solar cell element at the time of irradiating simulated sunlight with a cell of 25 ° C., 100 mW / cm ² and spectrum AM1.5 global.
Table 1 shows the results. The screen print processing tact is an average value.

  As shown in Table 1, in Example 1 printed by the screen printing machine of the present invention, when compared with Comparative Example 1, the appearance inspection pass rate and conversion efficiency of a good solar cell element were maintained, and the solar cell element It was possible to reduce the processing tact in the screen printing process of the conductive paste. In addition, since it is difficult for the paste to protrude from both ends of the squeegee, it is possible to reduce the labor of scraping the paste protruding from the center to the center, and it is possible to save labor when the number of processed sheets is increased in the future. This printing method can be widely used for general screen printing methods.

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 N-type diffused layer 3 Antireflection film and passivation film 4 BSF layer 5 Front surface electrode 6 Back surface electrode 7 Screen plate 8 Scraper 9, 99 Squeegee 9a Paste scraping surface 10 Printing stage 11 Substrate 12 Paste 13 Extrusion paste 14 Convex Part 15 Recess

Claims (8)

  A scraper that coats the screen plate with a paste, and a paste coated on the screen plate while being moved while the tip portion presses the screen plate is pushed out from the opening portion of the screen plate to a substrate to be printed. A method of manufacturing a solar cell element using a screen printing machine equipped with a squeegee to screen-print a conductive paste on a substrate for a solar cell element to form an electrode, wherein the squeegee is moved by printing the squeegee A plurality of convex portions and / or concave portions for restricting the flow of the paste are arranged in a line at predetermined intervals in the squeegee length direction in a region in contact with the paste at the time of printing in the front direction. Manufacturing method of solar cell element.   The substrate for the solar cell element is a semiconductor substrate in which a diffusion layer is formed and an antireflection film is formed thereon, and a conductive paste is screened on the antireflection film using the screen printer. The method for manufacturing a solar cell element according to claim 1, wherein the electrode is formed by printing.   The method for manufacturing a solar cell element according to claim 1, wherein the plurality of convex portions and concave portions are alternately arranged on the front surface in the printing movement direction of the squeegee.   The manufacturing method of the solar cell element according to any one of claims 1 to 3, wherein an adjacent interval between adjacent convex portions and / or concave portions is 1 to 100 mm.   The said some convex part and / or a recessed part are arranged in parallel with the outer edge of the said front-end | tip part of a squeegee, The manufacturing of the solar cell element of any one of Claims 1-4 characterized by the above-mentioned. Method.   The method for manufacturing a solar cell element according to any one of claims 1 to 5, wherein the convex portion has a cylindrical shape.   The said recessed part is a round hole, The manufacturing method of the solar cell element of any one of Claims 1-6 characterized by the above-mentioned.   A scraper that coats the screen plate with a paste, and a paste coated on the screen plate while being moved while the tip portion presses the screen plate is pushed out from the opening portion of the screen plate to a substrate to be printed. A screen printing machine including a squeegee, wherein the squeegee includes a plurality of convex portions and / or concave portions that regulate flow of the paste in a region in contact with the paste during printing in front of the squeegee in a printing movement direction. A screen printer for forming electrodes of solar cell elements, which is arranged in a line at predetermined intervals in the squeegee length direction.

Images