JP2006049831A - Manufacturing method for photovoltaic panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase tolerance of outer diameter, shape, and sphericity of a photovoltaic element (granular silicon) used for manufacturing a photovoltaic panel. <P>SOLUTION: A plastic sealing material 23 is filled into a recess 21 of a cradle 22 and a molding die 24 is set on the cradle 22, then the granular photovoltaic element 11 is stored singly in each bowl-shaped recess 26 of the molding die 24, and then each photovoltaic element 11 is pressed from above to fit a lower part of the each photovoltaic element 11 into a through-hole 27 of the each bowl-shaped recess 26, and then the lower part of the each photovoltaic element 11 is pressed into the plastic sealing material 23 in the recess 21 such that a lower end of the each photovoltaic element 11 is contacted or substantially contacted to the bottom of the recess 21 of the cradle 22. After that, a resin liquid of a transparent resin 12 is injected into a molding cavity 25 of the molding die 24, thereby a photovoltaic panel 10 is molded, in which many photovoltaic elements 11 are integrated in a panel form by the transparent resin 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photovoltaic panel manufacturing method in which a large number of granular photovoltaic elements are arranged in a staggered pattern or a matrix pattern and are molded into a panel shape with a transparent resin.

  In recent years, for example, Patent Document 1 (Japanese Patent Publication No. 7-54855) and Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-164554) have been proposed in order to increase the power generation efficiency of photovoltaic panels that convert solar energy into electrical energy. As shown, there is one in which the photovoltaic element is formed in a granular shape (or spherical shape). Granular photovoltaic elements have the advantage that the element projected area (light receiving amount) seen from the light incident direction is almost constant with respect to sunlight incident from various directions, so that it is possible to generate power efficiently even when the solar altitude is low. There is.

  In the techniques of these Patent Documents 1 and 2, granular silicon is fitted into a large number of circular holes formed in the base plate that also serves as a surface electrode, and the granular silicon exposed portion protruding on the lower surface side of the base plate is interposed via an insulating layer. An electrode is formed.

  However, in the techniques of Patent Documents 1 and 2, the area of the granular silicon light receiving region exposed on the upper surface side of the base plate and the size (height) of the electrode forming region on the lower surface side are the same as the circular holes formed in the base plate. Since it is determined by the relationship between the inner diameter and the outer diameter of the granular silicon, in order to make the area of the granular silicon light receiving area and the size (height) of the electrode forming area uniform, High uniformity is required for true spherical accuracy. For this reason, the management of the granular silicon manufacturing process is complicated, the productivity of the granular silicon is lowered, the yield of the granular silicon is deteriorated, and the manufacturing cost is increased.

  In addition, it is necessary to form an ohmic contact at the junction between the electrode and the granular photovoltaic device. For this purpose, electrode material is directly deposited on the photovoltaic device, or a contact hole is provided on the photovoltaic device. There is a method of forming an insulating film and depositing an electrode material on the portion of the photovoltaic element exposed from the contact hole.

  For example, in the electrode forming method disclosed in Patent Document 3 (Japanese Patent Laid-Open No. 2004-63564), the second semiconductor layer on the spherical first semiconductor surface is opened to expose a part of the first semiconductor, and the exposed portion of the first semiconductor. And a method of forming internal electrodes on the outer periphery of the second semiconductor, respectively, and an electrical insulating layer having a plurality of recesses provided with connection holes at the bottom, and a second formed in the recesses as the connection holes, leaving the periphery. After preparing a support made of a conductor layer, and then placing the spherical photovoltaic device in the recess so as to contact the periphery of the second conductor layer opening and the first semiconductor exposed portion connection hole, and welding the joint Each electrode is connected to a corresponding conductor layer by soldering or the like.

  In addition, in the electrode forming method disclosed in Patent Document 4 (Japanese Patent Application Laid-Open No. 2004-95826), at least one electrode is formed by applying conductive ink to the surface of the spherical photovoltaic device by an ink jet method and heat-treating it. To do. With this method, the first electrode is formed on the exposed surface of the spherical first conductor, and the second electrode is formed on a part of the outer peripheral surface of the second conductivity type semiconductor layer.

  Moreover, the electrode formation method of patent document 5 (Unexamined-Japanese-Patent No. 2004-140217) forms a 1st electrode in the 1st semiconductor in the opening part of the 2nd semiconductor layer on the surface of a photovoltaic device, A second electrode is formed on the outer periphery, and the second electrode is disposed at a predetermined position of the concave portion of the support made of the electrical insulating layer and the second conductive layer, and the first electrode and the first conductive layer are soldered by the first solder. Then, the second electrode is brought into contact with the second conductive layer with solder having a liquidus temperature lower than the solidus temperature of the solder of the first electrode.

  In the technologies of these Patent Documents 3, 4, and 5, in order to form an ohmic electrode on a spherical photovoltaic device, high uniformity is required for the outer diameter size and shape of spherical silicon and the true spherical accuracy. In addition, there is a drawback in that high sphericity accuracy is required between the base plate and the granular silicon, resulting in low mass productivity and high manufacturing cost.

In Patent Document 6 (Japanese Patent Laid-Open No. 2003-282480), an electrode material is applied by rubbing a disk or brush made of an electrode material to a semiconductor electrode forming portion, and sintering is performed by frictional heat accompanying rubbing. Although a method is disclosed, frictional heat and physical force acting on the sealing material around the electrode portion may work, and the resin layer holding the photovoltaic element may be damaged.
Japanese Patent Publication No. 7-54855 JP 2002-164554 A JP 2004-63564 A JP 2004-95826 A JP 2004-140217 A JP 2003-282480 A

  The present invention has been made in order to solve the above-described problems. Therefore, the object of the present invention is to satisfy the required quality level of the photovoltaic panel, while maintaining the outer diameter size, shape and trueness of the photovoltaic element (granular silicon). It is an object of the present invention to provide a photovoltaic panel manufacturing method that can widen an allowable range for the sphere accuracy and can realize improvement in productivity and yield of photovoltaic elements without deteriorating product quality. Another object of the present invention is to provide an optical device capable of easily forming an ohmic contact resistance portion at the junction between the electrode and the photovoltaic device without damaging the resin layer holding the photovoltaic device. It is providing the manufacturing method of an electric power generation panel.

In order to achieve the above object, according to the first aspect of the present invention, a large number of granular photovoltaic elements are arranged and formed into a panel shape with a transparent resin, and a part of each photovoltaic element protrudes from the resin portion. In the method for manufacturing a photovoltaic panel, a plurality of bowl-shaped recesses for receiving the plurality of photovoltaic elements one by one are formed in a molding cavity, and the bottom of each bowl-shaped depression is formed on each photovoltaic element. Using a molding die in which a circular through hole partially protruding downward is formed, and a cradle in which a relief recess is formed at least in a portion facing the through hole,
Filling the relief recess of the cradle with a plastic sealing material;
Setting the mold on the cradle;
Storing one photovoltaic element in each bowl-shaped recess of the mold;
By pressing the photovoltaic elements housed in the bowl-shaped recesses of the mold from above, the lower portions of the photovoltaic elements are fitted into the through holes of the bowl-shaped recesses, and the plastic sealing material An element pushing process for pushing a substantially constant amount inside,
Injecting a resin liquid of the transparent resin into a molding cavity of the mold;
Curing the resin liquid in the molding cavity of the mold and molding a photovoltaic panel in which the photovoltaic elements are integrated into a panel with a transparent resin;
Removing the photovoltaic panel from the molding cavity of the molding die.

  In short, in the present invention, a plastic sealing material is filled in the relief recess of the cradle, a molding die is set on the cradle, and each photovoltaic element housed in each bowl-shaped recess of the molding die is viewed from above. Press down and fit the lower part of each photovoltaic device into the through hole of each bowl-shaped recess and push it into the plastic seal material in the relief recess of the cradle by an almost constant amount, then inside the molding cavity of the mold A photovoltaic panel in which a number of photovoltaic elements are integrated into a panel shape with a transparent resin is formed by injecting a resin solution of a transparent resin into the resin. In this way, even if there is some variation in the outer diameter size, shape, and true sphere accuracy of the photovoltaic elements used in the production of the photovoltaic panel, the amount of element protrusion from the resin portion of the photovoltaic panel is made uniform. The gap between the through hole of each bowl-shaped recess and the photovoltaic element caused by variations in the outer diameter size, shape, and true spherical accuracy of the photovoltaic element can be sealed with a plastic sealing material. Can be prevented (in this case, the viscosity of the resin may be adjusted to prevent the resin leakage more reliably). As a result, the allowable range for the outer diameter size, shape and true spherical accuracy of photovoltaic elements (granular silicon) can be expanded while meeting the required quality level of photovoltaic panels, improving the productivity of photovoltaic elements and yield. Improvements can be realized without compromising product quality.

  In this case, as in claim 2, in the element pushing step, the lower end of each photovoltaic element is pushed by pushing the lower end of each photovoltaic element so as to contact or substantially contact the bottom surface of the relief recess of the receiving base. It is preferable to push the plastic seal material into the plastic seal material by a substantially constant amount. In this way, the amount of element protrusion from the resin portion can be made uniform by an extremely simple operation, and productivity can be further increased. However, in the present invention, the lower part of the photovoltaic device may be pushed into the plastic sealing material by a substantially constant amount by adjusting the viscosity of the plastic sealing material.

  Further, as in claim 3, the outer peripheral surface of each photovoltaic device is in contact with the inner peripheral edge of each through-hole in a state where the lower end of each photovoltaic device is in contact with or substantially in contact with the bottom surface of the recess of the cradle. Or it is good to set the hole diameter of each through-hole so that it may be in the substantially contact | abutted state. In this way, in the element pushing step, the gap between the through hole of each bowl-shaped recess and the photovoltaic element can be reduced, and a part of the plastic seal material is pushed into the bowl-shaped recess from the gap. This can be prevented, and the boundary between the photovoltaic device and the resin portion can be formed smoothly. Thereby, the electrode (light reflecting surface) around the boundary between the photovoltaic element and the resin portion can be smoothly formed in the step of forming the electrode that also serves as the light reflecting surface on the back surface side of the photovoltaic panel. The amount of reflected light received by the power generation element can be increased, and the photovoltaic power generation efficiency can be increased.

  Further, as in claim 4, it is preferable to form an electrode on a portion protruding from the resin portion of each photovoltaic element of the photovoltaic panel. In the present invention, since the element protrusion amount from the resin portion is made uniform, the size and height position of the electrode formed on the protrusion portion can be made uniform.

  In the inventions according to claims 1 to 4 described above, the relief recesses of the cradle are filled with the plastic sealing material. However, as in claim 5, the molding is formed on the cradle not filled with the plastic sealing material. The mold is set in a state where there is a gap between at least the part facing the through hole, and one photovoltaic element is accommodated in each bowl-shaped recess of the molding die, and the lower part of each photovoltaic element is After fitting into the through-hole of the bowl-shaped recess to bring the lower end of each photovoltaic element into contact with or substantially in contact with the receiving table, a resin solution of transparent resin is injected into the molding cavity of the mold Then, the photovoltaic panel may be formed by curing. Even in this way, even if there is some variation in the outer diameter size, shape, and true sphere accuracy of the photovoltaic element, the element protruding amount from the resin portion can be made uniform by an extremely simple operation. The size and height position of the electrode formed in the part can be made uniform. In addition, the tolerance for the outer diameter, shape, and true spherical accuracy of the photovoltaic element (granular silicon) can be expanded, and improvement in productivity and yield of the photovoltaic element can be realized without sacrificing product quality. it can.

  Also in this case, as in the sixth aspect, the outer peripheral surface of each photovoltaic element is in contact with or substantially in contact with the inner peripheral edge of each through hole in a state where the lower end of each photovoltaic element is in contact with or substantially in contact with the cradle. It is preferable to set the hole diameter of each through-hole so as to be in contact. In this way, when the resin liquid is injected into the molding cavity of the mold, the gap between the through hole of each bowl-shaped recess and the photovoltaic device can be reduced, and the resin liquid leaks from the gap. This can be prevented.

  Further, as in claim 7, it is preferable to form an electrode on a portion protruding from the resin portion of each photovoltaic element of the photovoltaic panel. Also in this case, since the element protrusion amount from the resin portion is made uniform, the size and height position of the electrode formed on this protrusion portion can be made uniform.

  In the invention according to claims 1 to 7 described above, a molding die is used to mold the resin portion of the photovoltaic panel. However, in the invention according to claim 8, the plastic seal filled in the recess of the cradle. A molding cavity is formed in the material, and this is used as a molding die. Specifically, after filling the recess formed on the upper surface side of the cradle with a plastic sealing material, a transfer mold for transferring the shape of the molding cavity for molding the resin portion of the photovoltaic panel is used as the plastic sealing material. By pressing, a molding cavity having a large number of bowl-shaped recesses in which a large number of photovoltaic elements are accommodated one by one is formed in the plastic sealing material, and one photovoltaic element is provided in each bowl-shaped recess of the molding cavity. After being housed one by one, each photovoltaic element housed in each bowl-shaped recess is pressed from above, and the lower part of each photovoltaic element is pushed into the plastic sealing material by a certain amount, and then transparent into the molding cavity. A resin liquid of resin may be injected and cured. Even in this case, even if there is some variation in the outer diameter size, shape, and true sphere accuracy of the photovoltaic element, the element protrusion amount from the resin portion of the photovoltaic panel can be made uniform, and the photovoltaic element The boundary with the resin portion can be formed smoothly.

  Also in this case, as in claim 9, in the element pushing step, the lower end of each photovoltaic element is pushed by pushing the lower end of each photovoltaic element so as to contact or substantially contact the bottom surface of the recess of the receiving base. It is preferable to push the plastic seal material into the plastic seal material by a substantially constant amount. In this way, the amount of element protrusion from the resin portion can be made uniform by an extremely simple operation, and productivity can be further increased.

  Furthermore, as in claim 10, it is preferable to form an electrode on a portion protruding from the resin portion of each photovoltaic element of the photovoltaic panel. Also in this case, since the element protrusion amount from the resin portion is made uniform, the size and height position of the electrode formed on this protrusion portion can be made uniform.

  In order to achieve another object, the invention according to claim 11 is arranged in such a manner that a large number of granular photovoltaic elements are arranged and formed into a panel shape with a transparent resin, and a part of each photovoltaic element is a resin portion. In the method of manufacturing a photovoltaic panel in which an electrode is formed on the exposed portion, the electrode is formed on a portion of the photovoltaic element exposed from the resin portion, and then the laser beam is applied to the electrode. Thus, an ohmic contact resistance portion is formed at the junction between the electrode and the photovoltaic element. In this way, even if there is some variation in the outer diameter size, shape, and true sphere accuracy of the photovoltaic elements used in the production of photovoltaic panels, the electrodes and photovoltaic elements are joined by laser beam sintering. An ohmic contact resistance portion can be easily formed in the portion.

  Hereinafter, three Examples 1 to 3 embodying the best mode for carrying out the present invention will be described.

  A first embodiment of the present invention will be described with reference to FIGS. First, the structure of the photovoltaic panel 10 manufactured by the manufacturing method of the present embodiment will be described with reference to FIG.

  The photovoltaic panel 10 has a large number of granular photovoltaic elements 11 arranged in a zigzag or matrix shape and integrated with a transparent resin 12 (resin portion). As the transparent resin 12, for example, a light transmissive ultraviolet curable resin may be used.

  Each photovoltaic device 11 has an n-type semiconductor layer formed thinly on the outer periphery, and a p-type semiconductor layer on the inner periphery. The method for producing the photovoltaic element 11 is not particularly limited. For example, as shown in International Publication WO99 / 10935, a silicon droplet that has been heated and melted is freely dropped, and the silicon droplet is subjected to surface tension. A free-fall method in which a spherical shape is deformed and solidified, or as shown in Japanese Patent Laid-Open No. 2002-60943, a spherical photovoltaic device is manufactured by depositing Si on the entire surface of a core material in a plasma CVD apparatus. The plasma CVD method may be used, or other manufacturing methods may be used.

  On the back surface side (upper surface side in FIG. 15) of the photovoltaic panel 10, an n-electrode 13 is formed so as to cover the back side of the transparent resin 12. . The n-electrode 13 is completely covered with two insulating resin layers 14 and 15. The lower insulating resin layer 14 functions as a protective layer (mask) during etching, which will be described later, and the upper insulating resin layer 15 functions as an insulating layer that insulates the n electrode 13 and the p electrode 16.

  A portion where the n-type semiconductor layer is partially removed by polishing or the like to expose the p-type semiconductor layer is formed at the rear end portion of each photovoltaic element 11, and the p-electrode 16 is conducted to the p-type semiconductor layer. It is formed as follows. The p-electrode 16 is completely covered and protected / insulated by a weather-resistant protective insulating layer 17 made of an insulating resin or the like.

  A method for manufacturing the photovoltaic panel 10 configured as described above will be described. As described above, the method for manufacturing the granular photovoltaic element 11 is not particularly limited, and the granular photovoltaic element 11 may be manufactured by any method. The process up to the production of the photovoltaic panel 10 may be performed consistently, or the photovoltaic panel 10 may be produced by purchasing a photovoltaic element 11 manufactured by another manufacturer. Hereafter, each process of manufacturing the photovoltaic panel 10 using the granular photovoltaic element 11 manufactured with the some method is demonstrated in order based on FIG. 1 thru | or FIG.

[1] Plastic Seal Material Filling Step First, as shown in FIG. 1, a cradle 22 having a shallow relief recess 21 formed on the upper surface side is used, and the plastic seal material is placed in the relief recess 21 of the cradle 22. 23 is filled. The plastic sealing material 23 is made of a material that can be plastically deformed, has a sealing property that does not penetrate the resin liquid of the transparent resin 12 (ultraviolet curable resin), and does not adhere to the transparent resin 12. Specifically, as the plastic sealing material 23, oil clay, glue, urethane-based sealing material for tile joints, thermosetting liquid silicone rubber for die cutting, or the like may be used.

  The depth dimension of the relief recess 21 of the cradle 22 is substantially the same as or slightly larger than the protrusion amount (element protrusion amount) of the photovoltaic element 11 from the transparent resin 12 of the photovoltaic panel 10. Set to dimensions.

[2] Mold Die Setting Process After the plastic seal material filling process is completed, the process proceeds to the mold setting process, and the mold 24 is set on the cradle 22 as shown in FIG. The molding cavity 25 of the mold 24 is formed with a large number of bowl-shaped recesses 26 in which a large number of photovoltaic elements 11 are accommodated one by one, and one photovoltaic element 11 is provided at the bottom of each bowl-shaped recess 26. A circular through-hole 27 whose portion protrudes downward is formed. Although only three hook-shaped recesses 26 are shown in FIGS. 2 to 6, many hook-shaped recesses 26 are actually formed.

[3] Photovoltaic element accommodation process After the molding die setting process is completed, the process proceeds to the photovoltaic element accommodation process, and as shown in FIG. 3, the photovoltaic elements 11 are accommodated one by one in each bowl-shaped recess 26 of the molding die 24. . In addition, after accommodating the photovoltaic device 11 in each bowl-shaped recessed part 26 of the shaping | molding die 24, you may make it set this shaping | molding die 24 on the receiving stand 22. FIG.

[4] Element Pushing Process After the photovoltaic element housing process is completed, the process proceeds to the element pushing process, and as shown in FIG. 4, each photovoltaic element 11 housed in each bowl-shaped recess 26 of the mold 24 is attached to a jig ( (Not shown) and pressed from above to fit the lower portion of each photovoltaic element 11 into the through hole 27 of each bowl-shaped recess 26, and inside the plastic sealing material 23 in the escape recess 21 of the cradle 22. Push in almost a certain amount. In this element pushing step, the lower end of each photovoltaic element 11 is pushed so as to abut or substantially abut against the bottom surface of the relief recess 21 of the pedestal 22, thereby lowering the lower part of each photovoltaic element 11 of the plastic sealing material 23. It is only necessary to push a certain amount into the interior.

  In this case, the outer peripheral surface of each photovoltaic element 11 is in contact with the inner peripheral edge of each through-hole 27 in a state where the lower end of each photovoltaic element 11 is in contact with or substantially in contact with the bottom surface of the relief recess 21 of the cradle 22. The hole diameter of each through hole 27 is set so as to be in a substantially abutting state.

[5] Resin liquid injection process After the element pushing process is completed, the process proceeds to the resin liquid injection process, and the resin liquid of transparent resin 12 (ultraviolet curable resin) is injected into the molding cavity 25 of the mold 24 as shown in FIG. Thus, all the bowl-shaped recesses 26 are completely submerged in the resin liquid. At this time, the gap between the through hole 27 of each bowl-shaped recess 26 and the photovoltaic element 11 is sealed with the plastic sealing material 23, and resin leakage from the gap is prevented.

[6] Resin curing process After the resin liquid injection process is completed, the process proceeds to the resin curing process. As shown in FIG. 6, the resin liquid of the transparent resin 12 (ultraviolet curable resin) in the molding cavity 25 of the mold 24 is irradiated with ultraviolet rays. By irradiating and curing the resin liquid, the photovoltaic panel 10 in which a large number of photovoltaic elements 11 are integrated into a panel shape with the transparent resin 12 is formed.

[7] Mold Release Process After the resin curing process is completed, the process proceeds to the mold release process, and the photovoltaic panel 10 is taken out from the molding cavity 25 of the mold 24 as shown in FIG.

[8] n-electrode formation process After the mold release process, the process proceeds to the n-electrode formation process. As shown in FIG. 8, conductor film formation such as vapor deposition, plating, coating, CVD, and sputtering is performed on the entire back surface of the photovoltaic panel 10. The n-electrode 13 is formed using a technique. As the conductor forming the n-electrode 13, it is preferable to use a conductor that has a small electrical resistance value such as Ag or an Ag-based conductor and easily reflects light (to function also as a reflection surface of incident light). The n-electrode 13 is electrically connected to the n-type semiconductor layer on the outer peripheral portion of each photovoltaic element 11 and covers the back side of the transparent resin 12 so as to function also as a reflection surface for incident light. Note that a part of the n-electrode 13 is removed so as to expose a part of the photovoltaic element 11 in a sandblasting process described later, and therefore there may be a part where the n-electrode 13 is not formed.

[9] Protection Layer (Lower Insulating Resin Layer) Formation Process After the n electrode formation process is completed, the process proceeds to the protection layer formation process. As shown in FIG. An insulating resin such as a resin is applied and cured to form a protective layer (lower insulating resin layer) 14, and the entire surface of the n electrode 13 is covered with the protective layer 14. The resin for forming the protective layer 14 may be any of thermosetting resin, ultraviolet curable resin, anaerobic curable resin, etc., but has insulation and etching resistance (to be used as a mask during etching). It is necessary to have. In addition, since a part of the protective layer 14 is removed so as to expose a part of the photovoltaic element 11 in the next sandblasting process, there may be a part where the protective layer 14 is not formed.

[10] Sandblasting process After the protective layer forming process is completed, the process proceeds to the sandblasting process. As shown in FIG. 10, the protective layer 14 and the n-electrode 13 at the rear end of each photovoltaic device 11 are partially removed by sandblasting. Then, the n-type semiconductor layer at the rear end of each photovoltaic element 11 is exposed. Instead of sandblasting, the protective layer 14 and the n-electrode 13 may be partially removed by polishing, laser processing, electric discharge processing, or the like.

[11] Etching Process After the sandblasting process, the process proceeds to the etching process, and the protective layer 14 is used as a mask (etching resist), and the n-type semiconductor layer at the rear end of the photovoltaic element 11 exposed from the protective layer 14 is chemically treated. Etching is performed to remove the p-type semiconductor layer inside. Note that dry etching may be used instead of chemical etching.

[12] Insulating layer (upper insulating resin layer) forming step After the etching step is completed, the process proceeds to the insulating layer (upper insulating resin layer) forming step, and as shown in FIG. Then, an insulating resin such as an epoxy resin is applied and cured to form an insulating layer (upper insulating resin layer) 15, and the n electrode 13 partially exposed in the sandblasting process is completely covered and insulated. To the state. The insulating layer 15 may be made of any of the same or different types of insulating resin as the protective layer 14 underneath, and any of thermosetting resin, ultraviolet curable resin, anaerobic curable resin, etc. It may be used. In addition, since a part of the insulating layer 15 is removed so that a part of the photovoltaic element 11 is exposed in the next polishing step, there may be a part where the insulating layer 15 is not formed.

[13] Polishing Step After the insulating layer forming step, the process proceeds to the polishing step. As shown in FIG. 12, the insulating layer 15 on the back surface of the photovoltaic panel 10 is polished and flattened by a polishing apparatus, and the photovoltaic element 11 The p-type semiconductor layer at the rear end of the p-type semiconductor layer is exposed from the insulating layer 15 and the exposed surface of the p-type semiconductor layer is planarized. In addition, you may make it grind | polish by sandblasting.

[14] p-electrode formation process After the polishing process, the process proceeds to the p-electrode formation process. As shown in FIG. 13, the p-electrode 16 is exposed on the entire back surface of the photovoltaic panel 10 and the p-type semiconductor layer of each photovoltaic element 11 is exposed. It is formed so as to be in close contact with the surface. The conductor forming the p-electrode 16 may be the same conductor as the n-electrode 13 described above, or a different conductor may be used, and the method of forming the p-electrode 16 may be the same as or different from the n-electrode 13. For example, vapor deposition, printing, or sputtering of a conductor such as aluminum may be used, or a conductor foil such as an aluminum foil may be attached to the entire back surface of the photovoltaic panel 10 to form the p electrode 16.

[15] Laser Sintering Step After the p-electrode forming step is completed, as shown in FIG. 14, the laser sintering step proceeds to the center of the junction between the p-electrode 16 and the p-type semiconductor layer at the rear end of each photovoltaic element 11 In the vicinity of the portion, laser light is irradiated in a predetermined pattern one or more times in a spot pattern, the portion is spot-heated, and a heat treatment (sinter) of the p-electrode 16 is performed to form an ohmic contact resistance portion. Do.

The laser used in this laser sintering process is, for example, a YVO ₄ laser (LD-excited solid laser), and the irradiation conditions were a Q switch frequency: 20 kHz, an irradiation area: a diameter of 0.3 mm, and an irradiation density: 25 μm. Under this condition, a good ohmic contact resistance portion was formed without damaging the transparent resin 12. The laser to be used is not limited to YVO ₄ laser (LD excitation solid laser), and the same effect can be obtained by using, for example, YAG laser, CO ₂ laser or the like. Moreover, it goes without saying that the above irradiation conditions are merely examples, and may be changed as appropriate.

  By the way, if the arrangement of the photovoltaic elements 11 in the photovoltaic panel 10 is an accurate equal pitch arrangement, the center position (laser light irradiation position) of the arranged photovoltaic elements 11 is uniquely determined. The position of each photovoltaic element 11 of the photovoltaic panel 10 is positioned with respect to the laser beam irradiating apparatus, and the process of irradiating the center position of each photovoltaic element 11 with the laser beam once or a plurality of times is photovoltaic. What is necessary is just to perform automatically in order according to the arrangement | sequence of the element 11. FIG.

  However, since the photovoltaic elements 11 used in the first embodiment have some variation in outer diameter size, shape, and true spherical accuracy, the arrangement of the photovoltaic elements 11 in the photovoltaic panel 10 is not necessarily equal pitch. It will not be. In such a case, the center position of each photovoltaic element 11 may be found one by one using a technique such as image processing, and laser light may be irradiated to that point one or more times. In this way, even if the arrangement of the photovoltaic elements 11 is not uniform, the laser beam can be accurately irradiated to the center position of each photovoltaic element 11.

[16] Protective insulating layer forming process After the laser sintering process, the process proceeds to the protective insulating layer forming process, and as shown in FIG. 15, an insulating resin is applied to the entire surface of the p-electrode 16 on the back surface of the photovoltaic panel 10 and cured. Thus, a weather-resistant protective insulating layer 17 is formed, and the entire surface of the p-electrode 16 is covered with the protective insulating layer 17. As the resin forming the protective insulating layer 17, any of thermosetting resin, ultraviolet curable resin, anaerobic curable resin, and the like may be used. If each process [1]-[16] demonstrated above is performed one by one, manufacture of the photovoltaic panel 10 will be completed.

  According to the manufacturing method of the photovoltaic panel 10 of the first embodiment described above, the relief seal 21 of the cradle 22 is filled with the plastic sealing material 23, the mold 24 is set on the cradle 22, and the molding is performed. The photovoltaic elements 11 housed in the bowl-shaped recesses 26 of the mold 24 are pressed from above, and the lower portions of the photovoltaic elements 11 are fitted into the through holes 27 of the bowl-shaped recesses 26 to A large number of photovoltaic elements 11 are injected by injecting a resin solution of the transparent resin 12 into the molding cavity 25 of the molding die 24 after being pushed into the plastic sealing material 23 in the escape recess 21 by a substantially constant amount. Since the photovoltaic panel 10 in which the transparent resin 12 is integrated into a panel shape is molded, there is some variation in the outer diameter size, shape, and true sphere accuracy of the photovoltaic element 11 used in the production of the photovoltaic panel 10. Even if there is photovoltaic power generation The amount of protrusion of the element 10 from the transparent resin 12 portion of the battery 10 can be made uniform, and the through hole 27 and light of each bowl-shaped recess 26 caused by variations in the outer diameter size, shape and true spherical accuracy of the photovoltaic element 11 The gap with the power generation element 11 can be sealed with the plastic sealing material 23, and resin leakage from the gap can be prevented (in this case, the resin leakage is adjusted to prevent the resin leakage more reliably. You may do it). Thereby, while satisfying the required quality level of the photovoltaic panel 10, the allowable range for the outer diameter size, shape, and true spherical accuracy of the photovoltaic element 11 can be expanded, and the productivity and the yield of the photovoltaic element 11 are improved. Can be realized without sacrificing product quality.

  Moreover, in the first embodiment, in the element pushing step, the lower end of each photovoltaic element 11 is pushed so as to abut or substantially abut against the bottom surface of the relief recess 21 of the pedestal 22. Thus, the element protrusion amount from the transparent resin 12 (resin portion) of the photovoltaic panel 10 can be made uniform, and the size and height position of the n-electrode 13 formed on this protrusion portion can be made uniform. In the present invention, by adjusting the viscosity of the plastic sealing material, the lower portion of the photovoltaic element may be pushed into the plastic sealing material by a substantially constant amount.

  Furthermore, in the first embodiment, the outer peripheral surface of each photovoltaic element 11 is within the through hole 27 in a state where the lower end of each photovoltaic element 11 is in contact with or substantially in contact with the bottom surface of the relief recess 21 of the cradle 22. Since the hole diameter of each through-hole 27 is set so as to be in contact with or substantially in contact with the peripheral edge, the gap between the through-hole 27 of each bowl-shaped recess 26 and the photovoltaic element 11 in the element pushing step. , And a portion of the plastic sealing material 23 can be prevented from being pushed into the bowl-shaped recess 26 through the gap, and the boundary between the photovoltaic element 11 and the transparent resin 12 can be formed smoothly. Can do. As a result, the n electrode 13 (light reflecting surface) around the boundary between the photovoltaic element 11 and the transparent resin 12 is smoothly formed in the step of forming the n electrode 13 serving also as the light reflecting surface on the back surface side of the photovoltaic panel 10. Therefore, there is an advantage that the amount of reflected light to the photovoltaic element 11 can be increased and the photovoltaic efficiency can be increased.

  In Example 1, the p-electrode 16 is formed on the portion of the photovoltaic element 11 exposed from the transparent resin 12, and then the p-electrode 16 is irradiated with laser light and sintered. Since an ohmic contact resistance portion is formed at the junction between the photovoltaic device 11 and the photovoltaic device 11, there is some variation in the outer diameter size, shape, and true sphere accuracy of the photovoltaic device 11 used in the production of the photovoltaic panel 10. Even if it exists, an ohmic contact resistance part can be easily formed in the junction part of the p electrode 16 and the photovoltaic device 11 by the sintering by a laser beam.

  In Example 1, the outer peripheral side of the photovoltaic element 11 is an n-type semiconductor layer and the inner peripheral side is a p-type semiconductor layer. On the contrary, the outer peripheral side is a p-type semiconductor layer and the inner peripheral side. May be an n-type semiconductor layer. In this case, the positions of the n electrode and the p electrode are also reversed, and an ohmic contact resistance portion may be formed at the junction between the n electrode and the photovoltaic element 11 by laser beam sintering.

  In addition, the technique of forming an ohmic contact resistance portion at the joint between the electrode and the photovoltaic element 11 by sintering with laser light is also applied to photovoltaic panels manufactured by a manufacturing method other than the first embodiment. it can.

  In the first embodiment, the relief recess 21 of the cradle 22 is filled with the plastic seal material 23. However, in the second embodiment of the present invention, as shown in FIG. 16, the plastic seal material 23 is not filled. A molding die 24 is set on the cradle 22, and as shown in FIG. 17, one photovoltaic device 11 is accommodated in each bowl-shaped recess 26 of the molding die 24, and the lower portion of each photovoltaic device 11 is placed at each lower portion. The lower end of each photovoltaic element 11 is fitted into the through hole 27 of the bowl-shaped recess 26 so as to be in contact with or substantially in contact with the bottom surface of the escape recess 21 of the base 22. Also in this case, the outer peripheral surface of each photovoltaic element 11 is in contact with the inner peripheral edge of each through-hole 27 in a state where the lower end of each photovoltaic element 11 is in contact with or substantially in contact with the bottom surface of the relief recess 21 of the cradle 22. Or it is good to set the hole diameter of each through-hole 27 so that it may be in the substantially contact | abutted state.

  Thereafter, as shown in FIG. 18, the photovoltaic panel 10 is molded by injecting the resin liquid of the transparent resin 12 into the molding cavity 25 of the molding die 24 and curing it. At this time, as the transparent resin 12, it is preferable to use an ultraviolet curable resin having a viscosity (non-fluidity) that does not leak from the gap between the through hole 27 of each bowl-shaped recess 26 and the photovoltaic element 11.

  After the molded photovoltaic panel 10 is taken out from the mold 24, each step from the [8] n-electrode forming step to the [16] protective insulating layer forming step is performed in the same manner as in the first embodiment. To be executed.

  Even in the second embodiment described above, the photovoltaic panel 10 can be obtained by a very simple operation even if there is some variation in the outer diameter size, shape, and true spherical accuracy of the photovoltaic element 11 used for manufacturing the photovoltaic panel 10. The amount of element protrusion from the transparent resin 12 can be made uniform, and the size and height position of the n-electrode 13 formed on this protrusion can be made uniform. In addition, the allowable range for the outer diameter size, shape, and true spherical accuracy of the photovoltaic device 11 can be expanded, and the productivity and yield of the photovoltaic device 11 can be improved without degrading the product quality.

  Further, the outer peripheral surface of each photovoltaic element 11 is in contact with or substantially in contact with the inner peripheral edge of each through hole 27 in a state where the lower end of each photovoltaic element 11 is in contact with or substantially in contact with the bottom surface of the relief recess 21 of the cradle 22. Since the diameters of the through holes 27 are set so as to be in contact with each other, when the resin liquid is injected into the molding cavity 25 of the molding die 24, the through holes 27 of the bowl-shaped recesses 26 and the light The gap with the power generation element 11 can be reduced, and the resin liquid can be more effectively prevented from leaking through the gap.

  In the second embodiment, the clearance recess 21 is formed on the upper surface of the cradle 22 so that a gap is formed between the molding die 24 and the cradle 22 for escaping the lower end of each photovoltaic element 11. However, as shown in FIG. 19, by forming a relief recess 24 a on the lower surface of the mold 24, a gap for allowing the lower end of each photovoltaic element 11 to escape is formed between the mold 24 and the cradle 22. You may do it. Alternatively, a gap-forming spacer may be sandwiched between the mold 24 and the cradle 22 so as to open a gap for releasing the lower end of each photovoltaic element 11. In this case, it is not necessary to form a relief recess in either the mold 24 or the cradle 22.

  In the first and second embodiments, the mold 24 is used to mold the transparent resin 12 (resin portion) of the photovoltaic panel 10, but in the third embodiment of the present invention shown in FIGS. A molding cavity 34 is formed in the plastic sealing material 33 filled in the recess 32 of the cradle 31 and used as a molding die.

  Specifically, as shown in FIG. 20, after filling the recess 32 formed on the upper surface side of the cradle 31 with the plastic sealing material 33, the transparent resin 12 of the photovoltaic panel 10 is applied as shown in FIG. By pressing a transfer mold 35 for transferring the shape of the molding cavity 34 to be molded against the plastic seal material 33, the molding cavity 34 having a large number of bowl-shaped recesses 36 in which a large number of photovoltaic elements 11 are accommodated one by one is formed. It forms in the plastic sealing material 33 (refer FIG. 22).

  Thereafter, as shown in FIG. 23, after one photovoltaic element 11 is accommodated in each bowl-shaped recess 36 of the molding cavity 34, each housed in each bowl-shaped recess 36 as shown in FIG. 24. The photovoltaic elements 11 are pressed from above, and the lower portions of the photovoltaic elements 11 are pushed into the plastic sealing material 33 by a substantially constant amount. At this time, the lower end of each photovoltaic element 11 is pushed so as to abut or substantially abut against the bottom surface of the recess 32 of the receiving base 31, so that the lower part of each photovoltaic element 11 is substantially constant inside the plastic sealing material 33. It is good to push in only the amount.

  Thereafter, as shown in FIG. 25, the resin liquid of the transparent resin 12 (ultraviolet curable resin) is injected into the molding cavity 34 so that all the bowl-shaped recesses 36 are completely submerged in the resin liquid. . Thereafter, as shown in FIG. 26, the resin liquid of the transparent resin 12 (ultraviolet curable resin) in the molding cavity 34 is irradiated with ultraviolet rays to cure the resin liquid, thereby making a large number of photovoltaic elements 11 transparent. After the photovoltaic panel 10 integrated into a panel shape with the resin 12 is molded, the photovoltaic panel 10 is taken out from the molding cavity 34 as shown in FIG. Thereafter, as in the first embodiment, the respective steps from the [8] n-electrode forming step to the [16] protective insulating layer forming step are sequentially performed.

  In the third embodiment described above, the transfer die 35 is pressed against the plastic seal material 33 filled in the recess 32 of the cradle 31 to form the molding cavity 34, and each of the housings accommodated in the bowl-shaped recesses 36 of the molding cavity 34. After the photovoltaic elements 11 are pressed from above and the lower portions of the photovoltaic elements 11 are pushed into the plastic sealing material 33 by a substantially constant amount, a resin liquid of transparent resin 12 (ultraviolet curable resin) is placed in the molding cavity 34. Since the photovoltaic panel 10 is molded by injecting the photovoltaic panel 10, even if there is some variation in the outer diameter size, shape, and true spherical accuracy of the photovoltaic element 11 used for manufacturing the photovoltaic panel 10, the photovoltaic panel The element protrusion amount from the 10 transparent resin 12 can be made uniform, and the size and height position of the n-electrode 13 formed on this protrusion portion can be made uniform. In addition, since the boundary between the photovoltaic element 11 and the transparent resin 12 can be formed smoothly, the photovoltaic element 11 is formed in the step of forming the n-electrode 13 that also serves as a light reflecting surface on the back surface side of the photovoltaic panel 10. The n electrode 13 (light reflecting surface) around the boundary between the transparent resin 12 and the transparent resin 12 can be formed smoothly, the amount of reflected light received by the photovoltaic element 11 can be increased, and the photovoltaic efficiency is increased. be able to.

It is a figure explaining the plastic sealing material filling process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the shaping | molding die setting process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the photovoltaic device accommodation process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the element pushing process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the resin liquid injection | pouring process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the resin hardening process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the mold release process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the n electrode formation process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the protective layer formation process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the sandblasting process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the insulating layer (upper insulating resin layer) formation process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the grinding | polishing process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the p electrode formation process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the laser sintering process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the protective insulating layer formation process in the manufacturing method of the photovoltaic panel of Example 1. FIG. It is a figure explaining the shaping | molding die setting process in the manufacturing method of the photovoltaic panel of Example 2. FIG. It is a figure explaining the photovoltaic device accommodation process in the manufacturing method of the photovoltaic panel of Example 2. FIG. It is a figure explaining the resin liquid injection | pouring process in the manufacturing method of the photovoltaic panel of Example 2. FIG. It is a figure explaining the other structural example of the shaping | molding die in a manufacturing method of the photovoltaic panel of Example 2, and a cradle. It is a figure explaining the plastic sealing material filling process in the manufacturing method of the photovoltaic panel of Example 3. FIG. It is a figure explaining the cavity shape transcription | transfer process in the manufacturing method of the photovoltaic panel of Example 3 (the 1). It is a figure explaining the cavity shape transcription | transfer process in the manufacturing method of the photovoltaic panel of Example 3 (the 2). It is a figure explaining the photovoltaic device accommodation process in the manufacturing method of the photovoltaic panel of Example 3. FIG. It is a figure explaining the element pushing process in the manufacturing method of the photovoltaic panel of Example 3. FIG. It is a figure explaining the resin liquid injection | pouring process in the manufacturing method of the photovoltaic panel of Example 3. FIG. It is a figure explaining the resin hardening process in the manufacturing method of the photovoltaic panel of Example 3. FIG. It is a figure explaining the mold release process in the manufacturing method of the photovoltaic panel of Example 3. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Photovoltaic panel, 11 ... Photovoltaic element, 12 ... Transparent resin (resin part), 13 ... N electrode, 14 ... Protective layer (lower insulating resin layer) 15 ... Insulating layer (upper insulating resin layer) , 16 ... p-electrode, 17 ... protective insulating layer, 21 ... relief recess, 22 ... cradle, 23 ... plastic sealing material, 24 ... molding die, 24a ... relief recess, 25 ... molding cavity, 26 ... bowl-like recess, 27 ... through hole, 31 ... cradle, 32 ... recess, 33 ... plastic sealing material, 34 ... molding cavity, 35 ... transfer mold, 36 ... bowl-shaped recess

Claims (11)

In a method of manufacturing a photovoltaic panel in which a large number of granular photovoltaic elements are arranged and molded into a panel shape with a transparent resin, and a part of each photovoltaic element is protruded from the resin portion,
A circular through-hole in which a plurality of bowl-shaped recesses for accommodating each of the plurality of photovoltaic elements is formed in the molding cavity, and a part of each of the photovoltaic elements protrudes downward at the bottom of each bowl-shaped recess. A mold formed with,
Using a cradle with a relief recess formed in at least a portion facing the through hole,
Filling the relief recess of the cradle with a plastic sealing material;
Setting the mold on the cradle;
Storing one photovoltaic element in each bowl-shaped recess of the mold;
By pressing the photovoltaic elements housed in the bowl-shaped recesses of the mold from above, the lower portions of the photovoltaic elements are fitted into the through holes of the bowl-shaped recesses, and the plastic sealing material An element pushing process for pushing a substantially constant amount inside,
Injecting a resin liquid of the transparent resin into a molding cavity of the mold;
Curing the resin liquid in the molding cavity of the mold and molding a photovoltaic panel in which the photovoltaic elements are integrated into a panel with a transparent resin;
Removing the photovoltaic panel from a molding cavity of the molding die. A method for producing a photovoltaic panel, comprising:   In the element pushing step, the lower end of each photovoltaic element is pushed into the bottom surface of the relief recess of the cradle so that the lower end of each photovoltaic element is placed inside the plastic seal material. 2. The method of manufacturing a photovoltaic panel according to claim 1, wherein a substantially constant amount is pushed into the panel.   A state in which the outer peripheral surface of each photovoltaic element is in contact with or substantially in contact with the inner peripheral edge of each through hole in a state in which the lower end of each photovoltaic element is in contact with or substantially in contact with the bottom surface of the relief recess of the cradle The method for manufacturing a photovoltaic panel according to claim 1, wherein the diameter of each through-hole is set so as to be.   The method for manufacturing a photovoltaic panel according to any one of claims 1 to 3, wherein an electrode is formed on a portion of each photovoltaic element of the photovoltaic panel protruding from the resin portion. In a method of manufacturing a photovoltaic panel in which a large number of granular photovoltaic elements are arranged and molded into a panel shape with a transparent resin, and a part of each photovoltaic element is protruded from the resin portion,
A circular through-hole in which a plurality of bowl-shaped recesses for accommodating each of the plurality of photovoltaic elements is formed in the molding cavity, and a part of each of the photovoltaic elements protrudes downward at the bottom of each bowl-shaped recess. A mold formed with,
Using a cradle for mounting the mold,
A step of setting the mold on the cradle in a state where a gap is opened at least in a portion facing the through hole between the molds;
One photovoltaic element is housed in each bowl-shaped recess of the mold, and the lower part of each photovoltaic element is fitted into the through-hole of each bowl-shaped recess, and the lower end of each photovoltaic element is received by the receiver. A step of contacting or substantially contacting the table;
Injecting a resin liquid of the transparent resin into a molding cavity of the mold;
Curing the resin liquid in the molding cavity of the mold and molding a photovoltaic panel in which the photovoltaic elements are integrated into a panel with a transparent resin;
Removing the photovoltaic panel from a molding cavity of the molding die. A method for producing a photovoltaic panel, comprising:   In a state where the lower end of each photovoltaic element is in contact with or substantially in contact with the cradle, the outer peripheral surface of each photovoltaic element is in a state of being in contact with or substantially in contact with the inner peripheral edge of each through hole. The method for manufacturing a photovoltaic panel according to claim 5, wherein a hole diameter of each through hole is set.   The method for producing a photovoltaic panel according to claim 5 or 6, wherein an electrode is formed on a portion of each photovoltaic element of the photovoltaic panel protruding from the resin portion. In a method of manufacturing a photovoltaic panel in which a large number of granular photovoltaic elements are arranged and molded into a panel shape with a transparent resin, and a part of each photovoltaic element is protruded from the resin portion,
Filling the recess formed on the upper surface side of the cradle with a plastic sealing material;
By pressing a transfer mold for transferring the shape of the molding cavity for molding the resin part of the photovoltaic panel to the plastic seal material, a plurality of bowl-shaped recesses for accommodating the numerous photovoltaic elements one by one are formed. Forming a molding cavity having the plastic sealing material;
Storing one photovoltaic element in each bowl-shaped recess of the molding cavity;
An element pushing step of pressing each photovoltaic element housed in each bowl-shaped recess of the molding cavity from above and pushing the lower part of each photovoltaic element into the plastic sealing material by a substantially constant amount; and
Injecting a resin liquid of the transparent resin into the molding cavity;
Curing the resin liquid in the molding cavity and molding a photovoltaic panel in which the photovoltaic elements are integrated into a panel with a transparent resin;
Removing the photovoltaic panel from the molding cavity. A method for producing a photovoltaic panel, comprising:   In the element pushing step, the lower end of each photovoltaic element is pushed into the bottom surface of the recess of the cradle so that the lower end of each photovoltaic element is pushed into the plastic sealing material. 9. The method of manufacturing a photovoltaic panel according to claim 8, wherein a substantially constant amount is pushed in.   The method for manufacturing a photovoltaic panel according to claim 8 or 9, wherein an electrode is formed on a portion of each photovoltaic element of the photovoltaic panel protruding from the resin portion. In a method of manufacturing a photovoltaic panel in which a large number of granular photovoltaic elements are arranged and formed into a panel shape with a transparent resin, and a part of each photovoltaic element is exposed from the resin part and electrodes are formed on the part. ,
After forming the electrode on the portion of the photovoltaic element exposed from the resin portion, the electrode is irradiated with laser light and sintered, so that an ohmic contact is formed at the junction between the electrode and the photovoltaic element. A method of manufacturing a photovoltaic panel, comprising forming a contact resistance portion.

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