JP2016100437A - Crystalline solar battery module and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a crystalline solar battery module which enables the achievement of superior connection reliability even in a crystalline solar battery module incorporating a crystalline solar battery cell of a bus bar-less structure; and a method for manufacturing such a crystalline solar battery module.SOLUTION: A crystalline solar battery module comprises: a glass substrate; a film-like base; and crystalline solar battery cells connected to each other by tab lines through a conductive adhesive cured product, and sealed between the glass substrate and the film-like base by a sealing resin. The conductive adhesive cured product is disposed on a light-receiving face of each crystalline solar battery cell, and a face on the side opposite to the light-receiving face so that the shortest distance from an edge of each crystalline solar battery cell to itself becomes 3-13 mm. The crystalline solar battery module has a layout region where the crystalline solar battery cells are laid out, and a non-layout region where the crystalline solar battery cells are not laid out outside the layout region. In the crystalline solar battery module, the shortest distance between an edge of the layout region and an edge of the crystalline solar battery module is 28-60 mm.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a crystalline solar cell module and a method for manufacturing the same.

  In a crystalline solar cell module, a plurality of crystalline solar cells are connected by tab wires, and a plurality of tab wires are connected to horizontal tab wires. To do. Conventionally, a tab wire coated with solder on the surface of a copper wire has been used, and the tab wire takes out the electric power generated by the solar cell by melting the solder and joining it to the bus bar electrode of the crystalline solar cell. It was. However, since high temperature is required for melting the solder, the crystal solar cell warps greatly when cooled to low temperature, and there are cases where cracks occur and shorts caused by solder that leaks out (leaked) from the tab wire. Occurred and caused the problem. Therefore, a conductive adhesive has been used as a connection material instead of solder. Since the conductive adhesive can be connected at a temperature lower than that of the solder, it is possible to reduce the problem of warping, cracking, and the like of the crystalline solar battery cell.

  Crystalline solar cells often have finger electrodes and bus bar electrodes, and these electrodes are electrically connected. The finger electrode is an electrode that collects electricity generated in the crystalline solar cell. The bus bar electrode is necessary when collecting electricity from the finger electrodes and joining the tab wires with solder. That is, electricity generated in a general crystalline solar cell is collected by the tab wire via the finger electrode and the bus bar electrode.

  Usually, finger electrodes and bus bar electrodes are formed by applying a silver paste. However, since the cost of crystalline solar cells can be reduced by reducing the silver paste, so-called bus bar-less crystalline solar cells and crystalline solar modules that do not use bus bar electrodes have been developed in recent years. ing. In particular, a crystalline solar cell module that uses a conductive adhesive to connect a crystalline solar cell and a tab wire can be manufactured by efficiently connecting a crystalline solar cell with a bus barless structure. Has been.

  However, a crystalline solar cell module using a crystalline solar cell having a bus barless structure in which a tab wire and a finger electrode of the crystalline solar cell are electrically connected via a conductive adhesive is a crystalline solar cell module. When the adhesiveness of the tab wire to the battery cell is not sufficient, there is a problem that the connection reliability of the crystalline solar battery module is lowered.

  On the other hand, in order to improve the adhesiveness of a finger electrode and a tab wire, the technique which forms a fillet in a conductive adhesive and improves adhesiveness is proposed (for example, refer patent document 1). However, in this technique, it is necessary to form fillet-forming electrodes on the crystalline solar cells, which increases the amount of silver paste used.

  Therefore, in a crystalline solar cell module using a crystalline solar cell having a busbarless structure, provision of a crystalline solar cell module with improved connection reliability at a low cost and a method for manufacturing the crystalline solar cell module is required. ing.

JP2013-219155A

  An object of the present invention is to provide a crystalline solar cell module having excellent connection reliability, and a method for manufacturing the crystalline solar cell module, even in a crystalline solar cell module using a crystalline solar cell having a busbarless structure. To do.

  In order to solve the above problems, the present invention provides a method in which a plurality of crystalline solar cells connected to each other by a tab wire through a cured product of a conductive adhesive are sealed between a glass substrate and a film-like substrate. It is a crystalline solar cell module sealed with resin, and the cured product of the conductive adhesive is each crystalline solar cell so that the shortest distance from the edge of each crystalline solar cell is 3 mm to 13 mm. Arranged on the light receiving surface of the battery cell and the surface opposite to the light receiving surface, the crystalline solar cell module has an arrangement region in which the crystalline solar cell is arranged, and a crystalline solar cell is arranged outside the arrangement region. There is provided a non-arranged region, and a crystalline solar cell module in which the shortest distance between the edge of the disposed region and the edge of the crystalline solar cell module is 28 mm to 60 mm.

  In this crystalline solar cell module, the cured product of the conductive adhesive is arranged so that the shortest distance from the edge of each crystalline solar cell is 3 mm or more. It can suppress that a crystalline solar cell breaks after a temperature cycle test. On the other hand, since the cured product of the conductive adhesive is arranged so that the shortest distance is 13 mm or less, it is possible to suppress a decrease in the current collection efficiency from the finger electrode, and when the tab wire is lifted, the crystal is crystallized. It can suppress that a tab wire peels from a system solar cell. Furthermore, in this crystalline solar cell module, since the shortest distance between the edge of the arrangement region and the edge of the crystalline solar cell module is 28 mm to 60 mm, the pressure when the crystalline solar cell module is pressurized is crystalline. It can suppress adding to the connection part of a solar cell and a tab wire too much. Therefore, the connection between the crystalline solar battery cell and the tab wire is preferably ensured, and the connection reliability is improved.

  It is preferable that the crystalline solar battery cell includes an electrode composed only of finger electrodes on the light receiving surface side. In this case, it is possible to reduce the cost of the crystalline solar cell and improve the production efficiency.

  In the present invention, a plurality of crystalline solar cells connected to each other by a tab wire through a cured product of a conductive adhesive are sealed with a sealing resin between a glass substrate and a film-like substrate. A method for manufacturing a crystalline solar cell module comprising: a strings manufacturing step of connecting a plurality of crystalline solar cells to form strings; a sealing resin; and a film substrate or a glass substrate. A coating step for coating the substrate, a sealing resin, and a glass substrate or a film-like base material are pressed and heated to seal the strings, and the placement region where the crystalline solar cells are placed, and the placement region And a sealing step for obtaining a crystalline solar cell module having a non-arranged region where no crystalline solar cell is disposed outside, the string manufacturing step receiving the crystalline solar cell. An applying step of applying a conductive adhesive to the surface opposite to the surface and the light receiving surface so that the shortest distance from the edge of the crystalline solar cell is 3 mm to 13 mm; and a tab wire on the conductive adhesive And a heating / pressurizing step for connecting a plurality of crystalline solar cells to each other by heating / pressurizing the tab wire. Provided is a method for manufacturing a crystalline solar cell module that covers the shortest distance from the edge of the solar cell module to 28 mm to 60 mm.

  In this method for manufacturing a crystalline solar cell module, the conductive adhesive is disposed so that the shortest distance from the edge of each crystalline solar cell is 3 mm or more. It can suppress that a crystalline solar cell breaks after a cycle test. On the other hand, since the conductive adhesive is disposed so that the shortest distance is 13 mm or less, it is possible to suppress a decrease in the current collection efficiency from the finger electrode, and when the tab wire is lifted, the crystalline solar cell The tab line can be prevented from peeling off. Further, in this method for manufacturing a crystalline solar cell module, since the shortest distance between the edge of the arrangement region and the edge of the crystalline solar cell module is 28 mm to 60 mm in the covering step, the crystalline solar cell It can suppress that the pressure at the time of pressurizing a module is excessively added to the connection part of a crystalline solar cell and a tab wire. Therefore, the connection between the crystalline solar battery cell and the tab wire is preferably ensured, and the connection reliability is improved.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the tab wire which protruded from the crystalline solar cell tries to peel a conductive adhesive at the time of a reliability test, etc., and the connection reliability of a conductive adhesive improves. Thereby, also in the crystalline solar cell module using the crystalline solar cell having the busbarless structure, it is possible to provide a crystalline solar cell module having excellent connection reliability and a method for manufacturing the crystalline solar cell module.

It is the top view seen from the light-receiving surface side which shows an example of the crystalline solar cell of this invention. It is the top view seen from the light-receiving surface side which shows another example of the crystalline solar cell of this invention. It is a schematic cross section which shows the provision process in the manufacturing method of the crystalline solar cell module of this invention. FIG. 4 is a schematic cross-sectional view showing a subsequent arrangement step of FIG. 3. It is a schematic cross section which shows another example of the arrangement | positioning process of FIG. It is the top view seen from the light-receiving surface side which shows an example of the crystalline solar cell connected by the tab wire. It is a top view which shows an example of the matrix in which the crystal system photovoltaic cells of FIG. 6 were connected. It is a principal part expanded sectional view which shows an example of the crystalline solar cell module of this invention. It is a principal part expanded sectional view which shows another example of the crystalline solar cell module of FIG. It is a schematic cross section which shows an example of the crystalline solar cell module of this invention.

  Hereinafter, a preferred embodiment of a crystalline solar cell module and a method for producing a crystalline solar cell module of the present invention will be described in detail with reference to the drawings.

(Crystal solar module)
A crystalline solar cell module according to an embodiment of the present invention has at least a crystalline solar cell, a tab wire, a cured product of a conductive adhesive, a glass substrate, a sealing resin, and a film-like base material, and further necessary. Depending on the, other members are included. A crystalline solar cell module is a solar cell module in which a tab wire and an electrode of a crystalline solar cell are electrically connected via a cured product of a conductive adhesive.

-(Crystal solar cell)
The crystalline solar battery cell has at least a crystalline photoelectric conversion element as a photoelectric conversion unit and a finger electrode, and further includes other members as necessary. The crystalline photoelectric conversion element is not particularly limited as long as it is a photoelectric conversion element having a crystalline photoelectric conversion material, and can be appropriately selected according to the purpose. Examples of the crystalline photoelectric conversion material include single crystal silicon, polycrystalline silicon, single crystal compounds such as GaAs, and polycrystalline compounds such as CdS and CdTe. The crystalline solar cell may have a bus bar-less structure that does not have a bus bar electrode.

-(Finger electrode)
The finger electrode is an electrode that collects electricity generated in the photoelectric conversion element. Most of the finger electrodes are formed in a direction substantially orthogonal to the tab line on the crystalline solar battery cell. Some finger electrodes may be orthogonal to other finger electrodes as auxiliary finger electrodes. The auxiliary finger electrode is connected to the finger electrode. If the finger electrode is damaged, the finger electrode may collect current from the adjacent finger electrode via the auxiliary finger electrode. The auxiliary finger electrode may assist the connection between the finger electrode and the tab wire. There is no restriction | limiting in particular as a material of a finger electrode, Although it can select suitably according to the objective, For example, silver, gold | metal | money, copper, tin, nickel etc. are mentioned.

  There is no restriction | limiting in particular as an average width | variety of a finger electrode, Although it can select suitably according to the objective, 20 micrometers-200 micrometers are preferable, and since light-shielding area can be reduced, 20 micrometers-100 micrometers are more preferable. The average width of the finger electrode can be obtained, for example, by measuring the width of the finger electrode at any 10 points of the finger electrode and averaging the measured values. The widths of the finger electrodes may not be the same at all locations, and some widths may be larger than others.

  There is no restriction | limiting in particular as a formation method of a finger electrode, According to the objective, it can select suitably, For example, silver paste is printed on a crystalline solar cell so that a finger electrode may become a desired pattern shape. A method is mentioned. Examples of the printing method include screen printing.

  There is no restriction | limiting in particular as average thickness of a crystalline solar cell, According to the objective, it can select suitably, For example, it can be set as 100-300 micrometers.

  Here, a crystalline solar cell will be described with reference to the drawings. FIG. 1 is a plan view showing an example of a crystalline solar battery cell. As shown in FIG. 1, the finger electrodes 2 are electrodes that collect electricity generated by the crystalline photoelectric conversion element 3, and are disposed substantially parallel to each other on the light receiving surface 1 a side of the crystalline solar cell 1. FIG. 2 is a plan view showing another example of the crystalline solar battery cell. As shown in FIG. 2, in the crystalline solar cell 21, the auxiliary finger electrode 4 is disposed so as to be orthogonal to the finger electrode 2 as an electrode for assisting the connection between the finger electrode 2 and the tab wire, for example. . The auxiliary finger electrode 4 may be used to connect the finger electrodes 2 in a region (details will be described later) where the conductive adhesive of the crystalline solar cell 21 is not applied.

  The crystalline solar cell finger electrode may be formed not only on one side of the crystalline solar cell but also on both sides. Thereby, it becomes possible to receive light from both surfaces of the crystalline solar battery cell.

-(Tab line)
The tab line is not particularly limited as long as it is a line that electrically connects adjacent crystalline solar cells, and can be appropriately selected according to the purpose. There is no restriction | limiting in particular as a structure of a tab line, According to the objective, it can select suitably, For example, the structure etc. which have a base material and a conductive layer are mentioned.

  The material of the base material is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include copper, aluminum, iron, gold, silver, nickel, palladium, chromium, molybdenum, and alloys thereof. It is done. There is no restriction | limiting in particular as an electroconductive layer, According to the objective, it can select suitably, For example, the electroconductive layer etc. which were formed by gold plating, silver plating, tin plating, solder plating, etc. are mentioned. There is no restriction | limiting in particular as average thickness of an electroconductive layer, Although it can select suitably according to the objective, 5 micrometers-20 micrometers are preferable. The average thickness can be obtained, for example, by measuring the thickness of the conductive layer at any 10 points of the conductive layer and averaging the measured values.

  There is no restriction | limiting in particular as a shape of a tab line, According to the objective, it can select suitably. In the cross section orthogonal to the longitudinal direction of the tab line, any cross sectional shape such as an elliptical shape, a rectangular shape, and a wave shape may be used. There is no restriction | limiting in particular as an average width | variety of a tab line, Although it can select suitably according to the objective, 0.5 mm-3 mm are preferable. There is no restriction | limiting in particular as average thickness of a tab wire, Although it can select suitably according to the objective, 5 micrometers-300 micrometers are preferable.

  There is no restriction | limiting in particular as a preparation method of a tab wire, According to the objective, it can select suitably, For example, the solder plating layer of average thickness 5micrometer-20micrometer was given to the copper foil rolled by average thickness 5micrometer-300micrometer A method of slitting a copper foil with a solder plating layer to an average width of 0.5 mm to 3 mm, a method of rolling a thin metal wire such as copper into a flat plate shape to an average width of 0.5 mm to 3 mm, and then solder plating Etc.

-(Conductive adhesive)
The conductive adhesive is used to electrically connect the finger electrode and the tab wire of the crystalline solar battery cell. The conductive adhesive is not particularly limited and may be appropriately selected depending on the purpose. For example, the conductive adhesive contains at least conductive particles, and preferably contains a film-forming resin, a curable resin, and a curing agent. In addition, a conductive adhesive containing other components may be used as necessary.

There is no restriction | limiting in particular as average thickness of a conductive adhesive, Although it can select suitably according to the objective, 3 micrometers-100 micrometers are preferable, 5 micrometers-30 micrometers are more preferable, and 8 micrometers-25 micrometers are especially preferable. When the average thickness is less than 3 μm, the adhesive strength may be remarkably lowered. When the average thickness is more than 100 μm, the conductive adhesive may protrude from the tab wire and a problem may occur in electrical connection. It is advantageous in terms of connection reliability that the average thickness is in a particularly preferable range. The average thickness is an average thickness measured before being temporarily attached. Here, the average thickness is an average value when five points are arbitrarily measured per 20 cm ² .

  There is no restriction | limiting in particular as an average width | variety of a conductive adhesive, Although it can select suitably according to the objective, It is 0.5 mm-3 mm, and it is preferable that it is a value below the width | variety of a tab wire.

-(Conductive particles)
The conductive particles are not particularly limited and can be appropriately selected depending on the purpose.For example, nickel particles, gold-coated nickel particles, resin particles obtained by coating a resin core with Ni, and resin cores coated with Ni, Furthermore, the resin particle etc. which coat | covered the outermost surface with Au are mentioned.

-(Film-forming resin)
The film-forming resin is not particularly limited and may be appropriately selected depending on the purpose. For example, phenoxy resin, unsaturated polyester resin, saturated polyester resin, urethane resin, butadiene resin, polyimide resin, polyamide resin, polyolefin resin Etc. These may be used individually by 1 type and may use 2 or more types together. Among these, phenoxy resin is particularly preferable.

-(Curable resin)
There is no restriction | limiting in particular as curable resin, According to the objective, it can select suitably, For example, an epoxy resin, an acrylate resin, etc. are mentioned. There is no restriction | limiting in particular as an epoxy resin, According to the objective, it can select suitably, For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, those modified epoxy resins, alicyclic epoxy Resin etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. The acrylate resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, epoxy acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane Triacrylate, dimethylol tricyclodecane diacrylate, tetramethylene glycol tetraacrylate, 2-hydroxy-1,3-diaacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2 -Bis [4- (acryloxyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclodecanyl acrylate, tris (acryloxyethyl) isocyanate Isocyanurate, and urethane acrylate. These may be used individually by 1 type and may use 2 or more types together. Moreover, what used the acrylate as the methacrylate is mentioned, These may be used individually by 1 type and may use 2 or more types together.

-(Curing agent)
The curable resin is preferably used in combination with a curing agent. There is no restriction | limiting in particular as a hardening | curing agent, According to the objective, it can select suitably, For example, imidazoles represented by 2-ethyl 4-methyl imidazole; Lauroyl peroxide, butyl peroxide, benzyl peroxide, diester Organic peroxides such as lauroyl peroxide, dibutyl peroxide, benzyl peroxide, peroxydicarbonate, benzoyl peroxide; anionic curing agents such as organic amines; cationic systems such as sulfonium salts, onium salts, aluminum chelators Examples thereof include a curing agent. Among these, a combination of an epoxy resin and an imidazole latent curing agent, and a combination of an acrylate resin and an organic peroxide curing agent are particularly preferable.

-(Other ingredients)
Other components are not particularly limited and may be appropriately selected depending on the purpose. For example, silane coupling agents, fillers, softeners, accelerators, anti-aging agents, colorants (pigments, dyes), An organic solvent, an ion catcher agent, etc. are mentioned. There is no restriction | limiting in particular in the addition amount of another component, According to the objective, it can select suitably.

-(Sealing resin)
The sealing resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, ethylene / vinyl acetate copolymer (EVA), ethylene / vinyl acetate / triallyl isocyanurate (EVAT), polyvinyl butyrate Examples thereof include lath (PVB), polyisobutylene (PIB), silicone resin, and polyurethane resin.

-(Film substrate)
There is no restriction | limiting in particular as a film-form base material, According to the objective, it can select suitably, For example, a moisture-proof back sheet and a translucent sheet | seat can be used.

-(Dampproof backsheet)
There is no restriction | limiting in particular as a moisture-proof backsheet, According to the objective, it can select suitably, For example, the laminated body of polyethylene terephthalate (PET), aluminum (Al), PET, Al, and polyethylene (PE) etc. are mentioned. It is done.

-(Translucent sheet)
There is no restriction | limiting in particular as a translucent sheet | seat, According to the objective, it can select suitably, For example, transparent sheets, such as a polyethylene terephthalate (PET), are mentioned.

-(Glass substrate)
There is no restriction | limiting in particular as a glass substrate, According to the objective, it can select suitably, For example, a soda-lime float glass substrate etc. are mentioned.

(Method for producing crystalline solar cell module)
The manufacturing method of the crystalline solar cell module according to the embodiment of the present invention includes at least a strings manufacturing process, a matrix manufacturing process, a covering process, and a sealing process, and further includes other processes as necessary.

-(Strings production process)
The string manufacturing process includes at least an applying process, an arranging process, and a heating / pressurizing process, and further includes other processes as necessary.

-(Granting process)
The applying step is not particularly limited as long as it is a step of applying a conductive adhesive to the light receiving surfaces of the plurality of crystalline solar cells and the opposite surface of the light receiving surface, and can be appropriately selected according to the purpose. The conductive adhesive may be in the form of a film or a paste. When the conductive adhesive is in the form of a film, the application step includes, for example, temporarily attaching a film-like conductive adhesive. When the conductive adhesive is in a paste form, the application process includes, for example, applying a paste-like conductive adhesive. There is no restriction | limiting in particular as a coating method, According to the objective, it can select suitably. In the application step, as shown in FIGS. 1 and 2, a conductive adhesive is applied to the application region 5 according to the position where the tab line is arranged.

  FIG. 3 is a schematic cross-sectional view showing the applying step. As shown in FIG. 3, the conductive adhesive 6 a is the shortest distance (hereinafter referred to as “offset”) between the conductive adhesive 6 a and the edge 1 b of the crystalline solar cell 1 on the light receiving surface 1 a of the crystalline solar cell 1. It is also referred to as “distance.”) It is arranged so that dx is preferably 3 mm to 13 mm, more preferably 4 mm to 12 mm. If the thickness is less than 3 mm, the crystalline solar cell may break after a heating / pressurizing step (described later) for connecting the tab wire to the crystalline solar cell with a conductive adhesive. If it exceeds 13 mm, the tab wire may be peeled off from the crystalline solar cell when the tab wire is lifted after the heating / pressurizing step. On the other hand, for example, a back electrode 7 is formed on a surface opposite to the light receiving surface 1 a of the crystalline solar cell 1, and a conductive adhesive 6 b is disposed on the back electrode 7.

-(Arrangement process)
FIG. 4 is a schematic cross-sectional view showing a subsequent arrangement step of FIG. If it is a process which arrange | positions the tab wires 8a and 8b which have a conductive layer on the conductive adhesives 6a and 6b arrange | positioned at the crystalline solar cell 1, respectively, as an arrangement | positioning process, after an application | coating process, especially There is no restriction | limiting, According to the objective, it can select suitably. In the arranging step, one tab wire is disposed on one light receiving surface of one crystal solar cell between two adjacent crystal solar cells, and the other end of the tab wire is the other crystal system. It arrange | positions on the surface opposite to the light-receiving surface of a photovoltaic cell (refer FIG.6,7,10).

--- (Heating / pressurizing process)
The heating / pressurizing step is not particularly limited as long as it is a step of heating and pressurizing the tab wire 8 subsequent to the arranging step, and can be appropriately selected according to the purpose. it can. The heating time, heating temperature, and pressure in the heating / pressurizing step are not particularly limited and can be appropriately selected depending on the purpose. As a result, as shown in FIGS. 5 and 6, separate tab wires 8 a and 8 b are connected to both surfaces of the crystalline solar cell 1 by the cured products of the conductive adhesives 6 a and 6 b, respectively. In addition, as shown in FIG. 5, the finger electrode 2 may be formed on both surfaces of the crystalline solar cell 31, and in this case, both surfaces 31a and 31b of the crystalline solar cell 31 are light receiving surfaces. The shortest distance between the cured product of the conductive adhesives 6a and 6b and the edge 1b of the crystalline solar cell 1 is the shortest distance between the conductive adhesives 6a and 6b and the edge 1b of the crystalline solar cell 1. Almost no change from distance.

  Through the above string manufacturing process, the finger electrode and the tab wire of the crystalline solar battery cell are electrically connected through the cured product of the conductive adhesive, and the plurality of crystalline solar battery cells are connected in series. Strings are created.

-(Matrix manufacturing process)
The matrix manufacturing process includes at least a process of electrically connecting a plurality of tab lines via the horizontal tab lines, and further includes other processes as necessary. The method for electrically connecting the plurality of tab lines via the horizontal tab lines is not particularly limited and can be appropriately selected according to the purpose. For example, each tab line and the horizontal tab line may be connected by soldering. As a connection method using solder, the connection may be performed by melting the solder while bringing the tab wire on which the solder plating is formed as the conductive layer into contact with the horizontal tab wire. As a result, as shown in FIG. 7, it is also possible to form a matrix 10 in which a plurality of strings 9 in which a plurality of crystalline solar cells 1 are connected in series are further arranged. In the matrix 10, the plurality of tab lines 8c, 8c (8d, 8d) in one string 9a (9b) are electrically connected to each other by the horizontal tab line 11a (11b), and the plurality of strings 9a, A plurality of tab lines 8e, 8e, 8f, 8f in 9b are electrically connected to each other by a horizontal tab line 11c.

-(Coating process)
The coating step is not particularly limited as long as the strings are coated with a sealing resin, and the sealing resin is a coating step with either a film-like substrate or a glass substrate, and is appropriately selected depending on the purpose. Can do. In the coating step, for example, it is preferable to arrange sealing resin, strings, sealing resin, and film-like base material in this order on a glass substrate, and to cover the strings using a reduced pressure laminator.

  There is no restriction | limiting in particular as sealing resin, a film-form base material, and a glass substrate, According to the objective, it can select suitably, For example, the sealing resin mentioned above, a film-form base material, a glass substrate etc. are mentioned.

-(Sealing process)
The sealing step includes at least a pressurizing step and a heating step, and further includes other steps as necessary. The pressurizing step is not particularly limited as long as it is a step of pressurizing either the film-like substrate or the glass substrate, and can be appropriately selected according to the purpose. The pressure to pressurize and the time to pressurize are arbitrary. Moreover, there is no restriction | limiting in particular as an order which starts a pressurization process and a heating process, According to the objective, it can select suitably.

  The heating step is not particularly limited as long as it is a step of heating the heating stage on which the strings are placed, and can be appropriately selected according to the purpose. The sealing resin can be heated by heating the heating stage. There is no restriction | limiting in particular as heating temperature in a heating process, Although it can select suitably according to the objective, 50 to 250 degreeC is preferable and 100 to 200 degreeC is more preferable. When the heating temperature is less than 50 ° C., sealing may be insufficient, and when the heating temperature exceeds 250 ° C., organic resins such as a conductive adhesive and a sealing resin may be thermally decomposed.

  There is no restriction | limiting in particular as heating time in a heating process, Although it can select suitably according to the objective, 1 second-1 hour are preferable, 5 seconds-30 minutes are more preferable, and 10 seconds-20 minutes are especially preferable. . If the heating time is less than 1 second, sealing may be insufficient. If it is 1 hour or longer, the reliability of the sealing resin may be lowered. As a result, as shown in FIGS. 8 and 9, the crystalline solar cell 1 (31) is sealed with the sealing resin 14 between the glass substrate 12 and the film-like base material 13. A battery module is obtained.

  As another process, the periphery of the sealed crystalline solar cell module may be surrounded by a metal frame such as aluminum. At that time, a rubber material such as silicone rubber or butyl rubber may be filled between the metal frame and the crystalline solar cell module.

  However, in the crystalline solar cell module manufactured by the above process, as shown in FIG. 10, the pressure distribution in the sealing process occurs in the edge portion 50 a of the crystalline solar cell module 50, and the sealing resin 14 is thinned. May occur. In a reliability test such as a temperature cycle test, stress is applied to the crystalline solar cell 1 or the tab wire 8 due to thermal expansion / contraction of the glass substrate 12, the film-like base material 13, the crystalline solar cell 1, or the tab wire 8. Occur. According to the study by the present inventors, it has been found that the stress is increased in the thinned portion of the sealing resin 14 at the edge 50a of the crystalline solar cell module 50. In particular, the stress that causes the tab wire 8 to be peeled off from the crystalline solar battery cell 1 may reduce the connection reliability due to the cured product of the conductive adhesive 6.

  Therefore, in the present invention, in order to keep the connection portion between the crystalline solar cell 1 and the tab wire 8 away from the thinned portion of the sealing resin 14, the crystalline solar cell from the edge 50 a of the crystalline solar cell module 50. The connection reliability of the conductive adhesive 6 (cured product) was improved by appropriately securing the distance to the conductive adhesive 6 (cured product) of 1.

  That is, in the covering step, each crystalline solar cell constituting the edge of the arrangement region R1 where the 50 crystalline solar cells 1 (strings 9) of the crystalline solar cell module are arranged (the edge of the arrangement region R1). The shortest distance X between the edge 1b) of the cell 1 and the edge 50a of the crystalline solar cell module 50 is preferably in the range of 28 to 60 mm, more preferably in the range of 30 to 60 mm, and 33 to 60 mm is most preferred. When the shortest distance X is less than 28 mm, the connection reliability of the conductive adhesive is likely to decrease, and when it exceeds 60 mm, the ratio of the area where no power is generated in the crystalline solar cell module increases and the power generation efficiency decreases. It is not preferable. The shortest distance X between the edge of the arrangement region R1 and the edge 50a of the crystalline solar cell module 50 is the crystal of the crystalline solar cell module 50 in the direction orthogonal to the edge 50a of the crystalline solar cell module 50. It can also be said that the length of the non-arrangement region R2 where the solar cell 1 is not arranged. The non-arrangement region R2 is located outside the arrangement region R1 and includes an area where only the tab line 8 is arranged.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
-(Preparation of crystalline solar cell with tab wire)
As the crystalline solar cell, a single-sided light-receiving solar cell (polycrystalline solar cell, size 156 mm × 156 mm, thickness 0.2 mm) using only finger electrodes as electrodes was used. Here, the average height of the finger electrodes was 24 μm, the average width was 100 μm, and the interval was 2 mm. Three conductive adhesive films were temporarily attached in a direction perpendicular to the finger electrodes. The offset distance dx was 4 mm. The conductive adhesive film (CF202, average thickness 5 μm, width 1.5 mm, manufactured by Hitachi Chemical Co., Ltd.) was used. The temporary bonding conditions were a heating temperature of 70 ° C., a pressure of 0.5 MPa, and 1 second, and a heating tool was used.

  Next, tab wires were placed on the conductive adhesive film. As the tab wires, three solder-coated tab wires (SSA-TP manufactured by Hitachi Cable Ltd., average thickness 0.2 mm, width 1.5 mm) having a solder layer (conductive layer, average thickness 20 μm) formed on the surface were used. . Then, the tab electrode is heated and pressed with a heating tool at a heating temperature of 190 ° C., a pressing force of 2 MPa, and a time of 5 seconds through a silicone sheet cushioning material (200 μm), thereby electrically bonding the finger electrode and the tab wire. They were electrically connected to each other through the agent film. Thus, a crystalline solar cell with tab wire was obtained.

-(Initial evaluation of crystalline solar cells)
The presence or absence of peeling of the tab line when the tab line of the obtained crystalline solar cell with tab line was lifted was evaluated. The results are shown in Table 1.

-(Production of crystalline solar cell module)
A glass substrate (tempered glass, size 403 mm × 403 mm, thickness 3.2 mm) is placed on the hot plate of the vacuum laminator, and a sealing resin (ethylene / vinyl acetate copolymer, size 403 mm × 403 mm, thickness) is placed thereon. 0.38 mm), four crystal solar cells with tab wires (2 rows × 2 columns) thereon, and sealing resin (ethylene / vinyl acetate copolymer, size 403 mm × 403 mm, thickness 0) thereon 38 mm), and a film-like substrate (a laminate film of PET, Al, and polyethylene (PE), size 403 mm × 403 mm, thickness 0.26 mm) was placed thereon. At this time, it installed so that the light-receiving surface of a crystalline solar cell might face a glass substrate side, and it installed so that the glass substrate, sealing resin, and the edge part of a film-like base material might be in line.

  In addition, the distance between the crystalline solar cells is adjusted so that the shortest distance X between the edge of the crystalline solar cell module and the arrangement region R1 is 44 mm, and the position of the crystalline solar cell from the module edge is adjusted. It was adjusted.

  The inside of the vacuum laminator was reduced in pressure for 5 minutes, then the reduced pressure was released and heated at 140 ° C. for 10 minutes. Then, it heated at 140 degreeC for 45 minute (s) in oven. Thus, a crystalline solar cell module was obtained. Thereafter, the outer periphery of the crystalline solar cell module was surrounded by an aluminum frame, and a silicone sealant material was injected and cured between the aluminum frame and the crystalline solar cell module. Thereby, a crystalline solar cell module for reliability evaluation was obtained.

-(Reliability evaluation of crystalline solar cell module)
The temperature cycle test of the obtained crystalline solar cell module for reliability evaluation (200 cycles of changing from 85 ° C. to −40 ° C.) was performed. A reverse bias was applied to the tabular crystalline solar cell by the electroluminescence (EL) method, and the in-plane distribution of the EL light was observed as an EL image. The presence or absence of cracks in the crystalline solar cells was evaluated from changes in the EL images before and after the temperature cycle test. The obtained results are shown in Table 1.

(Example 2)
Except that the offset distance dx is 8 mm, the production of the tabular crystalline solar cell and the initial evaluation of the crystalline solar cell are performed in the same manner as in Example 1, and the tab line of the crystalline solar cell is peeled off. The presence or absence of was evaluated. The results are shown in Table 1. Next, the production of the crystalline solar cell module and the reliability evaluation of the crystalline solar cell module were performed in the same manner as in Example 1, and the presence or absence of cracks in the crystalline solar cell was evaluated. The results are shown in Table 1.

(Example 3)
Except that the offset distance dx was set to 12 mm, the production of the tabular crystalline solar cell and the initial evaluation of the crystalline solar cell were performed in the same manner as in Example 1, and the tab line of the crystalline solar cell was peeled off. The presence or absence of was evaluated. The results are shown in Table 1. Next, the production of the crystalline solar cell module and the reliability evaluation of the crystalline solar cell module were performed in the same manner as in Example 1, and the presence or absence of cracks in the crystalline solar cell was evaluated. The results are shown in Table 1.

(Comparative Example 1)
Except that the offset distance dx was set to 2 mm, the fabrication of the crystalline solar cell with tab line and the initial evaluation of the crystalline solar cell were performed in the same manner as in Example 1, and the tab line of the crystalline solar cell was peeled off. The presence or absence of was evaluated. The results are shown in Table 1. Next, the production of the crystalline solar cell module and the reliability evaluation of the crystalline solar cell module were performed in the same manner as in Example 1, and the presence or absence of cracks in the crystalline solar cell was evaluated. The results are shown in Table 1.

(Comparative Example 2)
Except that the offset distance dx was set to 15 mm, the production of the tabular crystalline solar cell with the tab line and the initial evaluation of the crystalline solar cell were performed in the same manner as in Example 1, and the tab line peeling of the crystalline solar cell was performed. The presence or absence of was evaluated. The results are shown in Table 1. Next, the production of the crystalline solar cell module and the reliability evaluation of the crystalline solar cell module were performed in the same manner as in Example 1, and the presence or absence of cracks in the crystalline solar cell was evaluated. The results are shown in Table 1.

  From the above results, by controlling the offset distance dx within the range of 3 mm to 13 mm, the tab line does not peel off from the crystalline solar cell even when the tab line is lifted when handling the strings, and after the temperature cycle test Cracks do not occur in crystalline solar cells.

Example 4
In the same manner as in Example 1, a tabular crystalline solar cell was produced to obtain a tabular crystalline solar cell.

-(Production of crystalline solar cell module)
A glass substrate (tempered glass, size 1200 mm × 1020 mm, thickness 3.2 mm) is placed on a hot plate of a vacuum laminator, and a sealing resin (ethylene / vinyl acetate copolymer, size 1200 mm × 1020 mm, thickness) is placed thereon. 0.38 mm), 42 crystalline solar cells with tab wires (7 rows × 6 columns) are placed thereon, and a sealing resin (ethylene / vinyl acetate copolymer, size 1200 mm × 1020 mm, thickness) is placed thereon. 0.38 mm) and a film-like substrate (a laminate film of PET, Al, and polyethylene (PE), size 1200 mm × 1020 mm, thickness 0.33 mm) was placed thereon. At this time, it installed so that the light-receiving surface of a crystalline solar cell might face a glass substrate side, and it installed so that the glass substrate, sealing resin, and the edge part of a film-like base material might be in line.

  In addition, the spacing of the crystalline solar cells is adjusted so that the shortest distance X between the edge of the crystalline solar cell module and the arrangement region R1 is 33 mm, and the position of the crystalline solar cell from the module edge is adjusted. It was adjusted.

  The inside of the vacuum laminator was reduced in pressure for 5 minutes, and then the reduced pressure was released and heated at 140 ° C. for 10 minutes. Then, it heated at 140 degreeC for 45 minutes in oven. Thus, a crystalline solar cell module was obtained. Thereafter, the outer periphery of the crystalline solar cell module was surrounded by an aluminum frame, and a silicone sealant material was injected and cured between the aluminum frame and the crystalline solar cell module. Thereby, a crystalline solar cell module for reliability evaluation was obtained.

  About the obtained crystalline solar cell module for reliability evaluation, the same evaluation as Example 1 was performed. The results are shown in Table 2.

(Example 5)
A tabular crystalline solar cell was produced in the same manner as in Example 1 except that a crystalline solar cell using finger electrodes and bus bar electrodes as electrodes was used. Next, the production of the crystalline solar cell module as in Example 4 and the reliability evaluation of the crystalline solar cell module are performed, the presence or absence of cracks in the crystalline solar cell and the presence or absence of peeling of the tab wire are evaluated, It is shown in Table 2.

(Example 6)
A tabular crystalline solar cell was produced in the same manner as in Example 1. Next, except that the shortest distance X between the edge of the crystalline solar cell module and the arrangement region R1 was adjusted to 44 mm, the production of the crystalline solar cell module and the crystalline solar cell module were the same as in Example 4. Reliability evaluation was performed. The results are shown in Table 2.

(Example 7)
A tabular crystalline solar cell was produced in the same manner as in Example 1 except that a crystalline solar cell using finger electrodes and bus bar electrodes as electrodes was used. Next, except that the shortest distance X between the edge of the crystalline solar cell module and the arrangement region R1 was adjusted to 44 mm, the production of the crystalline solar cell module and the crystalline solar cell module were the same as in Example 4. Reliability evaluation was performed and the presence or absence of the crack of a crystalline solar cell and the presence or absence of peeling of a tab wire were evaluated. The results are shown in Table 2.

(Comparative Example 3)
A tabular crystalline solar cell was produced in the same manner as in Example 1. Next, except that the shortest distance X between the edge of the crystalline solar cell module and the arrangement region R1 was adjusted to 23 mm, the production of the crystalline solar cell module and the crystalline solar cell module were the same as in Example 4. Reliability evaluation was performed. The results are shown in Table 2.

(Comparative Example 4)
A tabular crystalline solar cell was produced in the same manner as in Example 1 except that a crystalline solar cell using finger electrodes and bus bar electrodes as electrodes was used. Next, except that the shortest distance X between the edge of the crystalline solar cell module and the arrangement region R1 was adjusted to 23 mm, the production of the crystalline solar cell module and the crystalline solar cell module were the same as in Example 4. Reliability evaluation was performed and the presence or absence of the crack of a crystalline solar cell and the presence or absence of peeling of a tab wire were evaluated. It is shown in Table 2.

  From the above results, by setting the shortest distance X between the edge of the crystalline solar cell module and the arrangement region R1 in the range of 28 mm to 60 mm, the crystal system in which the tab does not peel off after the reliability test and the crack does not occur. It turns out that a solar cell module is obtained.

  DESCRIPTION OF SYMBOLS 1, 21, 31 ... Crystalline solar cell, 6 ... Conductive adhesive, 8 ... Tab wire, 9 ... Strings, 12 ... Glass substrate, 13 ... Film-like base material, 14 ... Sealing resin, 50 ... Crystal system Solar cell module, R1 ... arrangement region, R2 ... non-arrangement region.

Claims (3)

A crystalline solar cell in which a plurality of crystalline solar cells connected to each other by tab wires through a cured product of a conductive adhesive are sealed with a sealing resin between a glass substrate and a film-like substrate A module,
The cured product of the conductive adhesive has a light receiving surface of each crystalline solar cell and a side opposite to the light receiving surface so that the shortest distance from the edge of each crystalline solar cell is 3 mm to 13 mm. Placed on the surface,
The crystalline solar cell module has an arrangement region where the crystalline solar cell is arranged, and a non-arrangement region where the crystalline solar cell is not arranged outside the arrangement region,
The crystalline solar cell module in which the shortest distance between the edge of the arrangement region and the edge of the crystalline solar cell module is 28 mm to 60 mm.   The crystalline solar cell module according to claim 1, wherein the crystalline solar cell includes an electrode composed of only a finger electrode on the light receiving surface side. A crystalline solar cell in which a plurality of crystalline solar cells connected to each other by tab wires through a cured product of a conductive adhesive are sealed with a sealing resin between a glass substrate and a film-like substrate A method of manufacturing a module,
A string production step of producing a string by connecting the plurality of crystalline solar cells,
A coating step of covering the strings with the sealing resin and the film-like substrate or the glass substrate;
The string is sealed by pressurizing and heating the sealing resin and the glass substrate or the film-like base material, an arrangement region where the crystalline solar cells are arranged, and an outside of the arrangement region And a sealing step of obtaining the crystalline solar cell module having a non-arrangement region in which the crystalline solar cell is not disposed.
The strings manufacturing process includes
Application step of applying a conductive adhesive to the light receiving surface of the crystalline solar cell and the surface opposite to the light receiving surface so that the shortest distance from the edge of the crystalline solar cell is 3 mm to 13 mm. When,
An arrangement step of arranging a tab wire on the conductive adhesive;
A heating / pressurizing step for connecting the plurality of crystalline solar cells to each other by heating / pressurizing the tab wire, and
The manufacturing method of the crystalline solar cell module which coat | covers so that the shortest distance of the edge of the said arrangement | positioning area | region and the edge of the said crystalline solar cell module may be 28 mm-60 mm in the said covering process.

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