JP5540738B2 - Insulating substrate for solar cell, solar cell module, and method for manufacturing solar cell insulating substrate - Google Patents

Description

  The present invention relates to an insulating material for fixing a back contact type solar cell having an electrode on the back surface, and a solar cell module using the insulating material.

  In recent years, solar power generation, which is a power generation system using natural energy, has been rapidly spread. As shown in FIG. 9, the solar cell module for performing photovoltaic power generation includes a translucent substrate 120 disposed on the light receiving side, a solar cell insulating substrate 110 disposed on the back side, and a translucent substrate. 120 and a large number of solar cells 130 arranged between the insulating substrate 110 for solar cells.

  Conventionally, in the solar cell module, a large number of solar cells 130 are electrically connected in series with a wiring material 150 having a width of 1 to 3 mm. Since the solar cell 130 is provided with a negative electrode (N-type semiconductor electrode) 131 on the front surface side that is the solar light receiving surface 130a and a positive electrode 132 on the rear surface side, the solar cell 130 is connected by the wiring member 150. The wiring material 150 overlaps on the light receiving surface 130a of the semiconductor, and the area efficiency of photoelectric conversion tends to be reduced. In the arrangement of the electrodes described above, the wiring member 150 wraps around from the front side to the back side of the solar battery cell 130. In such a structure, the wiring member 150 is disconnected due to a difference in thermal expansion of each member. There was a thing.

  In order to cope with the above problem, Patent Documents 1 and 2 propose a back contact type solar cell module in which both a positive electrode and a negative electrode are arranged on the back side of the cell. This type of connection between solar cells is performed by a circuit of an insulating substrate for solar cells disposed on the back side of the solar cells. By stacking the solar cells on this circuit, the light receiving area on the surface of the solar cells is not sacrificed, and the reduction in the area efficiency of photoelectric conversion can be avoided. Further, since it is not necessary to have a structure in which the wiring material is wound from the front side to the back side, disconnection of the wiring material due to the difference in thermal expansion of each member can be prevented.

JP 2005-11869 A JP 2009-111122 A

  Here, in the back contact type solar cell module, since gaps are formed between the plurality of solar cells in order to reduce the leakage current, a part of sunlight does not directly enter the solar cells. The light passes through the gap and enters the solar cell insulating substrate side. Due to the presence of sunlight that does not contribute to such power generation, it has been difficult to sufficiently improve the light utilization efficiency.

The present invention has been made in view of such a problem, and in a back contact solar cell module, an insulating substrate for solar cell and an insulating substrate for solar cell capable of improving the light utilization efficiency are provided. It aims at providing the manufacturing method of the used solar cell module and the insulating substrate for solar cells .

In order to solve the above problems, the present invention proposes the following means.
That is, the solar cell insulating substrate according to the present invention is laminated on the surface of the insulating material made of a composite material containing fibers and resin, and the surface of the insulating material, and is electrically connected to the solar cells. A concavo- convex structure is formed by transferring the concavo-convex structure of the metal foil onto the surface of the insulating material, and the concavo-convex structure is formed so as to mesh with the concavo-convex shape of the surface of the insulating material on the back surface of the circuit layer without gaps. The structure is molded, and the circuit layer has a gap that exposes the surface of the insulating material to the light receiving surface according to the shape of a pattern that electrically connects the plurality of solar cells in series.

  According to the solar cell insulating substrate having such a feature, the sunlight that has passed between the solar cells can be reflected by the concavo-convex structure of the insulating material and guided toward the solar cells, and thus reflected. The utilization efficiency of light can be improved when sunlight enters the solar battery cell.

  Furthermore, in the solar cell insulating substrate, an uneven structure is formed on the surface of the circuit layer in addition to the surface of the insulating material.

  As a result, sunlight can be reflected and guided to the solar cell even on the surface of the circuit layer having a high reflectivity, so that the sunlight reflected by this circuit layer is incident on the solar cell. The utilization efficiency can be further improved.

Moreover, in the said insulating substrate for solar cells, the said uneven structure shall be continuously arrange | positioned by the inclined surface which inclines at an angle of 20 degrees-80 degrees with respect to the surface direction of the said insulating material and a circuit layer. Is preferred.
Thereby, the light ray which injects into an uneven structure can be efficiently reflected toward a photovoltaic cell.

In the solar cell module, when the refractive index of the sealing layer laminated on the surface of the insulating material is n1, and the refractive index on the surface of the insulating material is n2, the relationship of n1> n2 is satisfied. It is preferable to be established.
As a result, a part of the sunlight that travels through the sealing layer and enters the insulating material is totally reflected, so that the light utilization efficiency can be further improved.

  The solar cell module according to the present invention includes a light-transmitting substrate disposed on the light-receiving surface side, a solar cell insulating substrate disposed on the back surface side of the light-transmitting substrate, and the solar cell insulating substrate. Furthermore, a solar cell comprising a barrier layer disposed on the back surface side, a solar battery cell disposed between the translucent substrate and the solar cell insulating substrate, and a sealing layer for sealing the solar battery cell. In the battery module, the solar cell insulating substrate is any one of the solar cell insulating substrates described above.

  According to the solar cell module having such a feature, the light passing through the solar cells out of the light incident on the sealing layer after passing through the translucent substrate is reflected by the uneven structure of the insulating material. Therefore, the light utilization efficiency can be improved when the reflected light beam enters the solar battery cell.

The method for manufacturing an insulating substrate for a solar cell according to the present invention is a method for manufacturing the insulating substrate for a solar cell, the step of forming an uneven structure on the back surface of the metal foil, and the back surface of the metal foil with fibers and half A step of laminating on the surface of a semi-cured composite material layer containing a cured thermosetting resin, and applying pressure heat treatment to the metal foil and the semi-cured composite material layer, The method includes a step of transferring the concavo-convex structure on the back surface of the metal foil, and a step of patterning the metal foil to form a circuit layer .

Thereby, it is possible to reliably form a concavo-convex structure on the surface of the insulating material, and to easily realize an insulating substrate for a solar cell that can improve the utilization efficiency of light. In addition, the uneven structure formed on the metal foil is laminated on the semi-cured composite material layer, and the uneven structure of the metal foil is not applied to the surface of the insulating material. Is transferred to the semi-cured composite material layer, and the semi-cured composite material layer is cured to form an insulating material, so that it is possible to mold the concavo-convex structure of the insulating material with a high molding rate. . Thereby, the light which injects into the surface of an insulating material can be efficiently reflected toward a photovoltaic cell.

According to the solar cell insulating substrate and the solar cell module of the present invention, the uneven structure provided on the surface of the insulating material reflects the light that has passed between the solar cells, and the light enters the solar cell module. Thus, it becomes possible to improve the utilization efficiency of sunlight .

It is a longitudinal cross-sectional view which shows schematic structure of the insulating substrate for solar cells which concerns on 1st Embodiment. It is a figure explaining the manufacturing method of the insulating substrate for solar cells shown in FIG. It is a longitudinal cross-sectional view which shows schematic structure of the solar cell module which concerns on 1st Embodiment. It is a figure explaining the manufacturing method of the solar cell module shown in FIG. It is a longitudinal cross-sectional view which shows schematic structure of the insulating substrate for solar cells which concerns on 2nd Embodiment. It is a figure explaining the manufacturing method of the insulating substrate for solar cells shown in FIG. It is a longitudinal cross-sectional view which shows schematic structure of the solar cell module which concerns on 2nd Embodiment. It is a figure explaining the manufacturing method of the solar cell module shown in FIG. It is a longitudinal cross-sectional view which shows schematic structure of the conventional solar cell module.

<First Embodiment>
(Insulating substrate for solar cell)
1st Embodiment of the insulating substrate for solar cells of this invention is described.
In FIG. 1, the insulating substrate for solar cells of this embodiment is shown. This solar cell insulating substrate 10 includes an insulating material 11 and a circuit layer 12 provided on the surface of the insulating material 11, and is used for connecting so-called back contact solar cells.

(Insulation material)
As the insulating material 11, a plate-shaped member made of a composite material containing fibers and resin, for example, a prepreg obtained by impregnating or applying a thermosetting resin to a fiber base material and drying it is used.
Examples of the fiber include glass fiber, aramid fiber, fluorine fiber, polyester fiber, and polyarylate fiber. Of these, glass fiber is preferable from the viewpoints of affinity with thermosetting resin, insulation reliability, and material cost.

  The resin is preferably an addition polymerization type thermosetting resin that cures without generating by-products. Examples of the addition polymerization type thermosetting resin include epoxy resin, unsaturated polyester resin, phenol resin, diallyl phthalate resin, acrylic resin, cyanate resin, cyanate ester resin-epoxy resin, cyanate ester-maleimide resin, cyanide. Acid ester-maleimide-epoxy resin, maleimide resin, maleimide-vinyl resin, bisallylnadiimide resin, and the like can be given. A thermosetting resin may be used individually by 1 type, and may use 2 or more types together.

  While the back surface of the insulating material 11 is molded flat, the concavo-convex structure A is molded on the surface. The concavo-convex structure A has a prism array shape in which triangular prisms extending in one direction (the depth direction in FIG. 1) are arranged side by side in a direction perpendicular to the one direction (the left-right direction in FIG. 1). That is, the concavo-convex structure A has a wave shape in which inclined surfaces having a predetermined angle with respect to the surface direction of the insulating material 11 (the two-dimensional direction including the left-right direction and the depth direction in FIG. 1) are continuously arranged. There is no.

  In addition, it is preferable that the inclination | tilt angle with respect to the insulating material 11 surface direction of the said inclined surface is set to the range of 20 degrees-80 degrees. When the tilt angle is less than 20 °, it is difficult to effectively reflect the light beam to the solar battery cell, and when it exceeds 80 °, it is difficult to mold the concavo-convex structure A.

  The concave-convex structure A of the insulating material 11 is not limited to the above prism array shape, that is, a corrugated shape. For example, a unit lens such as a cylindrical lens shape extending in one direction is perpendicular to the one direction. It may be in the form of a lens array arranged side by side, or has a configuration in which unit convex shapes such as a quadrangular pyramid shape (pyramid shape) are two-dimensionally arranged in the surface direction of the insulating material 11. There may be.

(Circuit layer)
The circuit layer 12 is a layer that is electrically connected to a solar battery cell to be described later, and is laminated on the surface of the insulating material 11 by pressure bonding. That is, a concavo-convex structure B that is the reverse of the concavo-convex structure A on the surface of the insulating material 11 is formed on the back surface of the circuit layer 12, and the concavo-convex structures A and B mesh with each other without a gap. And the insulating material 11 are integrated. In the present embodiment, the surface of the circuit layer 12 is formed flat.

  The circuit layer 12 has a pattern in which a large number of solar cells stacked on the solar cell insulating substrate 10 are electrically connected in series. For this reason, there is a gap that does not cover the entire surface of the insulating material 11 but exposes the surface of the insulating material 11 to the light receiving surface according to the shape of the pattern. As a material constituting the circuit layer 12, a material having low electric resistance, for example, copper, aluminum, iron-nickel alloy or the like is used. Moreover, a conductive polymer can also be used.

  In addition, it is preferable that the surface of the circuit layer 12 in this embodiment is roughened with a corrosive chemical such as formic acid, sulfuric acid, and nitric acid in order to improve adhesion to a stud bump described later. . Thereby, the adhesiveness between the circuit layer 12 and the member laminated on the surface of the circuit layer 12 can be improved.

  According to the solar cell insulating substrate 10 configured as described above, the solar cells can be electrically connected in series by stacking the solar cells on the circuit layer 12 provided on the surface of the insulating material 11. Thus, since lamination | stacking to the insulating substrate 10 for solar cells of a photovoltaic cell and connection of photovoltaic cells can be performed simultaneously, a photovoltaic module can be manufactured easily and the productivity can be made high.

  Furthermore, since the insulating material 11 is made of a composite material, the solar cell insulating substrate 10 is excellent in dimensional stability and rigidity. In particular, for example, the dimensional stability and the rigidity are superior to those of an insulating substrate for a solar cell made of a PET base material or a PEN base material that has been widely used conventionally. Therefore, when the insulating material 11 is made of a composite material, the solar cell insulating substrate 10 has excellent physical properties.

  Moreover, since the concavo-convex structure A is molded on the surface of the insulating material 11, the light beam that has passed between the solar cells is reflected along the inclined surface of the concavo-convex structure A. And since the reflected light rays enter the solar cells, the light rays that have passed between the solar cells can be reused, and the light utilization efficiency can be improved.

(Method for manufacturing an insulating substrate for solar cells)
A method for manufacturing the solar cell insulating substrate 10 of this embodiment will be described.
In the method for manufacturing the solar cell insulating substrate 10 according to the present embodiment, first, as shown in FIG. 2A, the concavo-convex structure B is formed on the back surface of the metal foil 18 made of a metal such as copper, aluminum, or iron-nickel alloy. Is molded. This concavo-convex structure B may be molded by, for example, machining using a bite or the like, or may be molded by etching. Further, a thin film made of a conductive polymer may be used in place of the metal foil 18.

  Next, as shown in FIG. 2B, the metal foil 18 is laminated on the surface of a semi-cured composite material layer 19 containing fibers and a semi-cured thermosetting resin. The semi-cured composite material layer 19 is obtained by impregnating or applying the thermosetting resin to the above-described fibers and drying. Since this thermosetting resin is in a semi-cured state, it has adhesiveness.

  And the back surface of the metal foil 18 is pressure-bonded to the surface of the semi-cured composite material layer 19 by subjecting the semi-cured composite material layer 19 and the metal foil 18 to heat vacuum bonding. At this time, the surface of the semi-cured composite material layer 19 is deformed according to the shape of the uneven structure B on the back surface of the metal foil 18, so that the uneven structure B on the back surface of the metal foil 18 is transferred to the surface of the semi-cured composite material layer 19. The Then, the thermosetting resin in the semi-cured composite material layer 19 is heated and cured, whereby the insulating material 11 having the concavo-convex structure A formed on the surface can be obtained as shown in FIG.

  Then, a circuit pattern 12 is formed by forming a resist pattern on the surface of the metal foil 18 and performing an etching process. In the formation of the circuit layer 12, photolithography is applied. In photolithography, first, a resist layer is provided on the entire surface of the metal foil 18. At this time, as the resist layer, a dry film resist may be used, or a wet resist may be applied to the metal foil 18 to be formed.

  Next, a photomask is placed on the resist layer, exposed, and developed to provide a resist pattern. Thereafter, the metal foil 18 not covered with the resist pattern is removed by etching. Etching may be either dry etching or wet etching, but usually wet etching is applied. Thereafter, the resist pattern is peeled off. In this way, the metal foil 18 can be made into the circuit layer 12 by patterning the metal foil 18, and the solar cell insulating substrate 10 made of the insulating material 11 and the circuit layer 12 as shown in FIG. 1. Can be obtained.

  The surface of the obtained circuit layer 12 may be roughened. As the roughening treatment, for example, a method of bringing a corrosive chemical solution such as formic acid, sulfuric acid, nitric acid into contact with the surface of the circuit layer 12 can be applied. Thereby, the adhesiveness of the circuit layer 12 and the member laminated | stacked on the surface of this circuit layer 12 can be improved.

  In such a method for manufacturing the solar cell insulating substrate 10, the uneven structure B is formed on the back surface of the metal foil 18, and the back surface of the metal foil 18 is laminated on the surface of the semi-cured composite material layer 19. The insulating substrate 10 for solar cells in which the insulating material 11 and the circuit layer 12 are firmly integrated can be obtained by heating and vacuum-compressing the 18 and the semi-cured composite material layer 19. Further, by transferring the concavo-convex structure B on the back surface of the metal foil 18 to the semi-cured composite material layer 19 and curing the semi-cured composite material layer 19 by this heat vacuum pressing, the insulating material 11 has a high molding rate. The uneven structure A can be easily molded.

  That is, since the method of transferring the concavo-convex structure B formed on the metal foil 18 is used instead of performing the process of directly forming the concavo-convex structure A on the back surface of the insulating material 11, with a high mold forming rate. The uneven structure A of the insulating material 11 can be formed. Thereby, the light which injects into the surface of the insulating material 11 can be reflected toward a photovoltaic cell more efficiently.

(Solar cell module)
The solar cell insulating substrate 10 is used in a solar cell module. FIG. 3 shows a solar cell module using the solar cell insulating substrate 10.
The solar cell module 1 includes a light-transmitting substrate 20 disposed on the light receiving surface side, a solar cell insulating substrate 10 disposed on the back surface side, and the light-transmitting substrate 20 and the solar cell insulating substrate 10. A large number of solar cells 30 arranged and a sealing layer 40 for sealing the solar cells 30 are provided.
Furthermore, a barrier layer 13 is disposed on the back side of the solar cell insulating substrate 10 used in the solar cell module 1, and stud bumps 14 are formed on the electrode portions 12 a of the circuit layer 12 that contact the solar cells 30. Is provided.

[Barrier layer]
The barrier layer 13 is a layer that adjusts air permeation. For the barrier layer 13, a material having long-term reliability such as weather resistance and insulation is used. For example, a fluororesin film, a low oligomer / heat-resistant polyethylene terephthalate (PET) film / polyethylene naphthalate (PEN) film, silica (SiO 2 ) Evaporated film, aluminum foil, etc. are used.

[Stud bump]
The stud bump 14 is a member that assists electrical connection between the circuit layer 12 and the solar battery cell 30, and is disposed so as to correspond to the electrode of the solar battery cell 30. As the material of the stud bump 14, a material having a low electric resistance is used. Especially, since the electrical resistance with the circuit layer 12 becomes low, it is preferable to contain 1 or more types of metals chosen from the group which consists of silver, copper, tin, lead, nickel, and gold.

  Since this stud bump 14 has a high viscosity and can be easily formed into a desired shape, it contains one or more metals selected from the group consisting of silver, copper, tin, and solder (copper and lead are the main components). It is preferable that the conductive paste is formed.

  The conductive paste is preferably a low temperature curing type. If the conductive paste is a low-temperature curing type, the solar cell electrode and the circuit layer 12 can be electrically connected at a low temperature of 120 to 160 ° C. Since 120 to 160 ° C. is a temperature at which softening, melting, and cross-linking of the EVA film that can be used as the sealing layer 40 occurs, when an EVA film is used as the sealing layer 40, the solar cell can be easily processed. The electrode of the cell 30 and the stud bump 14 formed from the conductive paste can be more easily electrically connected.

  Low-temperature curing type conductive paste contains a polymer and a conductive filler, and develops conductivity by physical contact of the conductive filler by curing the polymer. Coordinates and reduces silver or copper to organic matter The thing which contains a nanoparticle and expresses electroconductivity by carrying out low temperature sintering (120-160 degreeC) is mentioned. The latter material is preferable in that the electric resistance becomes lower.

[Translucent substrate]
Examples of the translucent substrate 20 include a glass substrate and a transparent resin substrate. Examples of the transparent resin constituting the transparent resin substrate include acrylic resin, polycarbonate, and polyethylene terephthalate.

[Solar cells]
Examples of the solar battery cell 30 include a single crystal silicon type, a polycrystalline silicon type, an amorphous silicon type, a compound type, and a dye sensitized type. Among these, the single crystal silicon type is preferable in terms of excellent power generation efficiency. The solar battery cell 30 includes positive and negative electrodes 31, 31 on the back side.

[Sealing layer]
The sealing layer 40 is formed of a sealing film. As the sealing film, for example, an EVA film, an ethylene / (meth) acrylate copolymer film, a fluororesin film such as polyvinylidene fluoride, or the like is used. Usually, two or more sealing films are used so as to sandwich the solar battery cell 30 therebetween.

  Here, when the refractive index of the sealing layer is n1 and the refractive index on the surface of the insulating material 11 is n2, the materials of the sealing layer 40 and the insulating material 11 are selected so that the relationship of n1> n2 is established. It is preferable that For example, when an epoxy resin is used as the resin constituting the insulating material 11, the sealing layer 40 is configured using an EVA film having a refractive index higher than that of the epoxy resin. As a result, it is possible to totally reflect a part of the light beam that travels in the sealing layer 40 and enters the insulating material 11, so that the light utilization efficiency can be further improved.

This solar cell module 1 is manufactured by the following manufacturing method, for example.
That is, first, as shown in FIG. 4A, the stud bumps 14 are formed on the electrode portions 12 a of the circuit layer 12, and the solar cells are arranged so that the stud bumps 14 face the electrodes 31 of the solar cells 30. 30 is disposed, and the laminated body including the solar cell insulating substrate 10, the stud bump 14, and the solar battery cell 30 is heated and pressurized. Thereby, the solar cell 30 is mounted on the circuit layer 12 of the insulating substrate 10 for solar cells.

  In addition, as a formation method of the stud bump 14, methods, such as plating, screen printing, dispensing, and transfer, are applicable, for example. In that case, it is preferable to use a conductive paste containing one or more metals selected from the group consisting of silver, copper, tin, and solder because the desired shape can be easily obtained. Furthermore, a low temperature curing type conductive paste is more preferable in that the electrode 31 of the solar battery cell 30 and the stud bump 14 can be more easily electrically connected.

  Next, as shown in FIG. 4 (b), the solar battery cell 30 is sealed with a sealing layer 40 so as to cover the solar battery cell 30 from the periphery on the surface side of the insulating material 11 of the solar battery insulating substrate 10. Stop. Thereby, the concavo-convex structure A of the insulating material 11 is in close contact with the sealing layer 40. Thereafter, as shown in FIG. 4C, the barrier layer 13 is integrally fixed to the back surface side of the insulating material 11, and the translucent substrate 20 is fixed integrally to the surface of the sealing layer 40. Thereby, as shown in FIG. 3, the solar cell module 1 in which the solar cells 30 are electrically connected in series by the circuit layer 12 can be obtained.

  According to the solar cell module 1 having such a configuration, the light that has passed through the light-transmitting substrate 20 and has entered the sealing layer 40 between the solar cells 30 is converted into the concavo-convex structure of the insulating material 11. A can be reflected. Therefore, the light utilization efficiency can be improved by the reflected light rays entering the solar battery cell 30.

<Second Embodiment>
(Insulating substrate for solar cell)
Next, 2nd Embodiment of the insulating substrate for solar cells of this invention is described.
FIG. 5 shows an insulating substrate for a solar cell according to this embodiment. Note that in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

The solar cell insulating substrate 50 according to the second embodiment is different from the solar cell insulating substrate 10 according to the first embodiment in that an uneven structure C is also formed on the surface of the circuit layer 12.
That is, a concavo-convex structure C similar to the concavo-convex structure A formed on the surface of the insulating material 11 is formed on the surface of the circuit layer 12 of the insulating substrate 50 for solar cells. Can be reflected along the inclined surface of the concavo-convex structure C. And since the reflected light rays enter the solar cells, the light rays that have passed between the solar cells can be reused, and the light utilization efficiency can be improved.

  In addition, when the circuit layer 12 is molded from, for example, copper, aluminum, iron-nickel alloy, or the like, these materials have a higher reflectance than the resin constituting the surface of the insulating material 11, so that the light utilization efficiency is further improved. Can be improved.

(Method for manufacturing an insulating substrate for solar cells)
A method for manufacturing the solar cell insulating substrate 50 according to this embodiment will be described.
In the method for manufacturing the solar cell insulating substrate 50 according to this embodiment, first, as shown in FIG. 6A, the uneven structure B is formed on the back surface of the metal foil 18 made of a metal such as copper, aluminum, iron-nickel alloy or the like. As well as forming the concavo-convex structure C on the surface. The concavo-convex structure C is formed by machining or etching in the same manner as the concavo-convex structure B.

  Next, in the same procedure as in the first embodiment, as shown in FIG. 6B, by laminating the metal foil 18 on the surface of the semi-cured composite material layer 19, and then subjecting it to a heat vacuum bonding process, As shown in FIG. 6C, the back surface of the metal foil 18 is pressure-bonded to the surface of the semi-cured composite material layer 19. After that, the metal foil 18 can be made into the circuit layer 12 by patterning the metal foil 18, and an insulating substrate 50 for a solar cell comprising the insulating material 11 and the circuit layer 12 as shown in FIG. 5 is obtained. be able to.

(Solar cell module)
The solar cell insulating substrate 50 is used in a solar cell module. FIG. 7 shows a solar cell module using the solar cell insulating substrate 50.
This solar cell module 60 includes a translucent substrate 20 disposed on the light receiving surface side, a solar cell insulating substrate 50 disposed on the back surface side, and the translucent substrate 20 and the solar cell insulating substrate 50. A large number of solar cells 30 arranged and a sealing layer 40 for sealing the solar cells 30 are provided.
Furthermore, a barrier layer 13 is disposed on the back side of the solar cell insulating substrate 50 used in the solar cell module 1, and stud bumps 14 are formed on the electrode portions 12 a that contact the solar cells 30 of the circuit layer 12. Is provided.

  This solar cell module 60 is manufactured by, for example, the following manufacturing method, similarly to the first embodiment liquid. That is, first, as shown in FIG. 8A, the stud bump 14 is formed on the electrode portion 12 a of the circuit layer 12 of the circuit layer 12, and the stud bump 14 is opposed to the electrode 31 of the solar battery cell 30. The solar battery cell 30 is disposed, and the laminate including the solar battery insulating substrate 50, the stud bump 14 and the solar battery cell 30 is heated and pressurized.

  Next, as shown in FIG. 8B, the solar battery cell 30 is sealed with a sealing layer 40, and as shown in FIG. 8C, the barrier layer 13 is integrated with the back surface side of the insulating material 11. Fix it. And the solar cell module by which the photovoltaic cell 30 was electrically connected in series by the circuit layer 12 as shown in FIG. 7 by fixing the translucent board | substrate 20 integrally on the surface of the sealing layer 40. 60 can be obtained.

  According to the solar cell module 60 having such a configuration, the light that has passed between the solar cells 30 out of the light that has passed through the translucent substrate 20 and entered the sealing layer 40 is converted into a concavo-convex structure of the insulating material 11. The light can be reflected not only by A but also by the concavo-convex structure C of the circuit layer 12. That is, since light can be reflected at the non-electrode portion 12b, which is a portion other than the electrode portion 12a in the circuit layer 12, and the reflected light can be effectively incident on the solar battery cell 30, the light utilization efficiency can be further increased. It becomes possible to improve.

As mentioned above, although embodiment of this invention was described in detail, unless it deviates from the technical idea of this embodiment, it is not limited to these, A some design change etc. are possible.
For example, the solar cell insulating substrates 10 and 50 of the embodiment are composed only of the insulating material 11 and the circuit layer 12, but after having the barrier layer 13 and the stud bump 14 from the beginning, the insulating material 11, You may comprise as a back sheet which consists of the circuit layer 12, the barrier layer 13, and the stud bump 14. FIG.

  Moreover, in the solar cell insulating substrates 10 and 50, an overcoat layer may be provided to cover a portion other than the electrode portion 12a of the circuit layer 12. Examples of the insulating material constituting the overcoat layer include an epoxy resin, an acrylic resin, and a urethane resin. These resins may be used alone or in combination of two or more. By providing this overcoat layer, short circuit between adjacent circuit layers 12 can be prevented, and corrosion of the circuit layer 12 by acetic acid gas released from the EVA film constituting the sealing layer 40 can be prevented.

DESCRIPTION OF SYMBOLS 1 Solar cell module 10 Insulating substrate 11 for solar cells Insulating material 12 Circuit layer 12a Electrode part 12b Non-electrode part 13 Barrier layer 14 Stud bump 18 Metal foil 19 Semi-hardened composite material layer 20 Translucent substrate 30 Solar cell 31 Electrode 40 Sealing layer 50 Insulating substrate 60 for solar cell Solar cell module A Uneven structure B Uneven structure C Uneven structure

Claims (6)

An insulating material in the form of a plate made of a composite material containing fibers and resin;
A circuit layer laminated on the surface of the insulating material and electrically connected to the solar battery cell,
An uneven structure is formed by transferring the uneven structure of the metal foil to the surface of the insulating material,
A concavo-convex structure is formed on the back surface of the circuit layer so as to mesh with the concavo-convex structure on the surface of the insulating material without a gap,
The said circuit layer has the clearance gap which exposes the surface of the said insulating material to the light-receiving surface side according to the shape of the pattern which connects the said several photovoltaic cell in series electrically, The insulating substrate for solar cells characterized by the above-mentioned.   2. The solar cell insulating substrate according to claim 1, wherein an uneven structure is formed on the surface of the circuit layer in addition to the surface of the insulating material.   The inclined structure in which the concavo-convex structure is formed by continuously inclining at an angle of 20 ° to 80 ° with respect to the surface direction of the insulating material and the circuit layer is provided. Insulating substrate for solar cells. It is a manufacturing method of the insulating substrate for solar cells as described in any one of Claim 1 to 3,
Forming a concavo-convex structure on the back surface of the metal foil;
Laminating the back surface of the metal foil on the surface of a semi-cured composite material layer containing fibers and a semi-cured thermosetting resin;
Applying pressure and heat treatment to the metal foil and the semi-cured composite material layer, and transferring the concavo-convex structure on the back surface of the metal foil to the surface of the semi-cured composite material layer;
And a step of patterning the metal foil to form a circuit layer. A method for manufacturing an insulating substrate for a solar cell. A translucent substrate disposed on the light-receiving surface side, a solar cell insulating substrate disposed on the back side of the translucent substrate, and the translucent substrate and the solar cell insulating substrate. A solar cell module comprising a solar cell and a sealing layer for sealing the solar cell,
The solar cell module, wherein the solar cell insulating substrate is the solar cell insulating substrate according to any one of claims 1 to 3 .   The relationship of n1> n2 is established, where n1 is a refractive index of the sealing layer laminated on the surface of the insulating material, and n2 is a refractive index of the surface of the insulating material. 5. The solar cell module according to 5.

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