JP2011159748A - Insulating substrate for solar cell, solar cell module, and method of manufacturing insulating substrate for solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulating substrate for solar cell that prevents warpage making a reverse surface side convex from occurring in a back-contact type solar cell module, to provide a solar cell module using the insulating substrate for solar cell, and to provide a method of manufacturing the insulating substrate for solar cell. <P>SOLUTION: The insulating substrate 10 for solar cell is composed of: an insulating material 11 made of a composite material containing fiber and resin and having solar cells arranged on a top surface thereof; and a circuit layer 12 laminated on the reverse surface of the insulating material 11 and electrically connected to the solar cell through-holes 11a bored in the insulating material 11 along a thickness. Here, uneven structures A are formed on the reverse surface of the insulating material 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  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 photovoltaic power generation includes a translucent substrate 120 disposed on the light receiving side, an insulating substrate 110 disposed on the back side, the translucent substrate 120, and insulation. And a large number of solar cells 130 arranged between the substrates 110.

  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 solar cells are connected by a circuit of an insulating substrate disposed on the back side of the solar cells. This insulating substrate has a structure in which a circuit layer is laminated on the surface of an insulating material, and solar cells are further laminated on the circuit layer. As a result, the light receiving area on the surface of the solar battery cell is not sacrificed, and a decrease in 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 solar cell module of the back contact system, a circuit layer is formed on the surface of the insulating material, and further, a solar cell is laminated on the circuit layer. Sometimes, when exposed to high temperatures, the solar cell module may be warped due to the difference in the coefficient of linear expansion between the insulating material, the circuit layer, and the solar cell.

  In other words, since the insulating substrate has a higher linear expansion coefficient than the solar cell and the light-transmitting substrate, the insulating material expands more than the solar cell and the light-transmitting substrate at a high temperature. Accordingly, there has been a concern that a convex warp occurs on the back side of the solar cell module, leading to a failure.

  The present invention has been made in view of such problems, and in a back-contact solar cell module, an insulating substrate for a solar cell capable of preventing the occurrence of a warp convex on the back surface side and the insulating substrate for a solar cell 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 has a plate shape made of a composite material containing fibers and resin, and is laminated on the insulating material in which solar cells are arranged on the surface, and the back surface of the insulating material, A circuit layer electrically connected to the solar battery cell through a through-hole formed in a thickness direction of the insulating material, and a concavo-convex structure is formed on the back surface of the insulating material. To do.

According to the solar cell insulating substrate having such a feature, since the concavo-convex structure is formed on the back surface of the insulating material, the volume ratio on the back surface side of the insulating material, that is, the space in the space on the back surface side of the insulating material. The volume ratio occupied by the insulating material is reduced. Thereby, the volume expansion on the back surface side of the insulating material can be suppressed smaller than that on the front surface side.
Also, among the circuit layers and solar cells that have a smaller linear expansion coefficient than the insulating material, the circuit layer is stacked on the back side of the insulating material, and the solar cells are stacked on the front side of the insulating material. Even at times, these circuit layers and solar cells can evenly suppress expansion of the insulating material from both sides.

Furthermore, in the said insulating substrate for solar cells, it is preferable that the value of the maximum height Rmax of the said uneven structure is set to the value of 10% or more of the thickness dimension of the said insulating material.
Thereby, the volume expansion | swelling in the back surface side of an insulating material can be reduced effectively.

Further, in the solar cell insulating substrate, the concavo-convex structure has a shape in which triangular prisms extending in one direction along the back surface of the insulating material are continuously arranged in a direction orthogonal to the one direction. It is preferable.
Further, the concavo-convex structure may have a shape in which unit convex shapes having a quadrangular pyramid shape are two-dimensionally arranged along the surface direction of the back surface of the insulating material.
Thereby, the volume expansion | swelling in the back surface side of an insulating material can be reduced more effectively.

  And the solar cell module according to the present invention includes a translucent substrate disposed on the light receiving surface side, a solar cell insulating substrate disposed on the back surface side of the translucent substrate, the translucent substrate, and the A solar cell module comprising a solar cell disposed between solar cell insulating substrates and a sealing resin for sealing the solar cell, wherein the solar cell insulating substrate is one of the above It is a solar cell insulating substrate.

  According to the solar cell module having such a feature, it is possible to prevent the occurrence of warpage in the insulating material. Therefore, it is possible to avoid a failure due to the warpage and to improve maintainability.

  The method for manufacturing an insulating substrate for a solar cell according to the present invention includes a step of forming a concavo-convex structure on the surface of a metal foil, and the surface of the metal foil is a surface of a semi-cured composite material layer containing fibers and a thermosetting resin. Laminating the laminated metal foil and the semi-cured composite material layer with heat and pressure treatment to make the semi-cured composite material layer an insulating material, and patterning the metal foil. Forming a circuit layer, and further comprising forming a through hole in the semi-cured composite material layer or the insulating material to expose a part of the circuit layer to the light receiving surface side. To do.

  Thereby, the concavo-convex structure can be easily formed on the back surface of the insulating material. In addition, it is possible to place solar cells electrically connected to the circuit layer on the surface side of the insulating material by forming a through hole that exposes the circuit layer on the surface side while arranging the circuit layer on the back surface of the insulating material. An insulating substrate for a solar cell can be realized.

According to the insulating substrate for solar cell and the solar cell module of the present invention, the volume expansion on the back surface side of the insulating material is reduced by forming the uneven structure, and the insulating material is expanded by the circuit layer and the solar battery cell. By restraining evenly from the front and back surfaces, it is possible to prevent the occurrence of warping that is convex on the back surface side of the insulating material.
Moreover, according to the manufacturing method of the insulating substrate for solar cells of this invention, the said insulating substrate for solar cells which can prevent curvature can be manufactured easily.

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

(Insulating substrate for solar cell)
An embodiment of an insulating substrate for a solar cell of the present invention will be described.
FIG. 1 shows an insulating substrate for a solar cell according to an embodiment. This insulating substrate 10 for solar cells includes an insulating material 11 and a circuit layer 12 provided on the back surface of the insulating material 11, and is used for connection of so-called back contact type solar cells.

(Insulation material)
As the insulating material 11, a plate-shaped member made of a composite material containing fibers and a resin, that is, a prepreg obtained by impregnating or applying a thermosetting resin to a fiber base material and drying it is used. As for this insulating material 11, a photovoltaic cell is arrange | positioned at the surface (surface which faces the upper direction of FIG. 1), and the circuit layer 12 is arrange | positioned at the back surface (surface which faces the lower direction of FIG. 1). The insulating material 11 is provided with a plurality of through holes 11a penetrating in the thickness direction (vertical direction in FIG. 1).

  Examples of the fiber used for the insulating material 11 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.

  The surface of the insulating material 11 is formed in a flat shape so as to stably stack and fix the solar cells, while the concavo-convex structure A is formed on the back 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.

  The uneven structure A of the insulating material 11 is not limited to the prism array shape described above. For example, a lens array in which unit lenses such as a cylindrical lens shape extending in one direction are arranged in parallel in the direction orthogonal to the one direction. The unit convex shape that forms a quadrangular pyramid shape (pyramid shape) or the like may be configured to be two-dimensionally arranged in the surface direction of the insulating material 11.

  The maximum height Rmax of the concavo-convex structure A is preferably set to a value of 10% or more of the thickness dimension of the insulating material 11. When the value of the maximum height Rmax is less than 10% of the thickness dimension of the insulating material, it is not preferable because the effect of preventing warpage described later cannot be effectively obtained.

(Circuit layer)
The circuit layer 12 is a layer electrically connected to a solar battery cell 30 to be described later, and is laminated on the back 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 back surface of the insulating material 11 is formed on the surface of the circuit layer 12, and the concavo-convex structures A and B mesh with the circuit layer 12 so as to engage with each other without a gap. The insulating material 11 is laminated and integrated. In the present embodiment, the back 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. As a material constituting the circuit layer 12, a material having a low electrical resistance, for example, copper, aluminum, iron-nickel alloy or the like is used, but it is formed from a material having a lower linear expansion coefficient than the resin constituting the insulating material 11. It is preferable that Moreover, a conductive polymer can also be used.

  Note that the surface of the circuit layer 12 in this embodiment is preferably roughened with a corrosive chemical such as formic acid, sulfuric acid, or nitric acid in order to improve the adhesion to the stud bumps. Thereby, the adhesiveness between the circuit layer 12 and the member laminated on the surface of the circuit layer 12 can be improved.

  Further, a portion facing the through hole 11 a of the insulating material 11 on the surface of the circuit layer 12 is an electrode portion 12 a for connecting to the solar battery cell 30. In other words, the through hole 11a of the insulating material 11 penetrates the insulating material 11 in the thickness direction at a location where the electrode portion 12a of the circuit layer 12 exists. Thereby, the electrode part 12a of the circuit layer 12 is exposed to the surface side of the insulating material 11, ie, the light-receiving surface side, through the through-hole 11a.

  In the solar cell insulating substrate 10 having such a configuration, the solar cells of the insulating material 11 are electrically connected to the electrode portions 12a of the circuit layer 12 provided on the back surface of the insulating material 11 through the through holes 11a. By doing so, the solar cells can be electrically connected in series. The electrode portion 12a and the solar cell are electrically connected by a stat bump provided in the through hole 11a. As described above, according to the solar cell insulating substrate 10 of the present embodiment, the solar cell module can be formed by simultaneously stacking the solar cells on the solar cell insulating substrate 10 and connecting the solar cells. Can be easily manufactured and its productivity can be increased.

  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.

  Here, since the uneven structure A is formed on the back surface of the insulating material 11 in the solar cell insulating substrate 10 of the present embodiment, the volume ratio of the back surface side of the insulating material 11, that is, the back surface of the insulating material 11. The proportion of the volume occupied by the insulating material 11 in the side space is reduced. Thereby, for example, when the solar cell module on which the solar cell insulating substrate 10 is mounted is exposed to high temperature by receiving direct sunlight, the volume expansion on the back surface side of the insulating material 11 is suppressed to be smaller than that on the front surface side. Can do.

  Further, among the circuit layer 12 and the solar battery cell having a smaller linear expansion coefficient than the insulating material 11, the circuit layer 12 is laminated on the back surface side of the insulating material 11, and the solar battery cell is laminated on the front surface side of the insulating material 11. Due to the configuration, the circuit layer 12 and the solar battery cell can evenly suppress the expansion of the insulating material 11 from both sides even at high temperatures.

  That is, according to the insulating substrate 10 for solar cells of this embodiment, the volumetric expansion on the back surface side of the insulating material 11 is reduced by forming the concavo-convex structure A, and the insulating material is formed by the circuit layer 12 and the solar battery cell. By suppressing the expansion of 11 evenly from both the front and back surfaces, it is possible to prevent the occurrence of warping that is convex on the back surface side of the insulating material 11.

(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 of the present embodiment, first, as shown in FIG. 2A, the uneven structure B is formed on the surface of the metal foil 18 made of a metal such as copper, aluminum, iron-nickel alloy or the like. 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 conductive polymer may be used in place of the metal foil 18.

  Next, as shown in FIG. 2B, the surface on which the concavo-convex structure B of the metal foil 18 is molded is laminated on the back surface of the 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 surface of the metal foil 18 is crimped | bonded to the back surface of the semi-hardened composite material layer 19 by performing a heating vacuum press-bonding process to these semi-hardened composite material layers 19 and the metal foil 18. At this time, the back surface of the semi-cured composite material layer 19 is deformed according to the shape of the uneven structure B on the surface of the metal foil 18, so that the uneven structure B on the surface of the metal foil 18 is transferred to the back 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 to obtain the insulating material 11 in which the concavo-convex structure A is molded on the surface area as shown in FIG. it can.

  Then, a circuit pattern 12 is formed by forming a resist pattern on the back 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 back 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. Next, 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. Thus, the metal foil 18 can be made into the circuit layer 12 by patterning the metal foil 18.

  Finally, cutting is performed from the surface side of the insulating material 11 with, for example, a laser or a drill to form a plurality of through holes 11 a in the insulating material 11. In addition, the place where the cutting process in the insulating material 11 is performed is a place corresponding to the electrode portion 12a of the circuit layer 12, and the cutting process is performed only on the insulating material 11, and the circuit layer 12 is not cut. It is stopped as follows. Thereby, the electrode part 12a of the circuit layer 12 is exposed to the light-receiving surface side through the through-hole 11a, and the insulating substrate 10 for solar cells shown in FIG. 1 can be obtained.

  The surface of the obtained circuit layer 12, that is, the electrode portion 12a may be subjected to a roughening treatment. 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. Adhesion between the circuit layer 12 and a member laminated on the surface of the circuit layer 12 can be improved.

  In such a method of manufacturing the solar cell insulating substrate 10, the uneven structure B is formed on the surface of the metal foil 18, and the surface of the metal foil 18 is laminated on the back 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 surface of the metal foil 18 to the semi-cured composite material layer 19 by this heat vacuum bonding, it is possible to easily form the concavo-convex structure A having a high moldability on the insulating material 11. .

  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 surface of the insulating material 11, with a high molding rate. The uneven structure A of the insulating material 11 can be formed. Thereby, the volume ratio on the back surface side of the insulating material 11 can be surely reduced, and the warpage that protrudes toward the back surface side of the insulating material 11 can be prevented.

(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 provided on electrode portions of the circuit layer 12 that contact the solar cells 30. It has been.

[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 provided so as to be filled in the through hole 11 a of the insulating material 11. 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 electrode of the solar battery cell 30 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. The solar battery cell 30 used in the present embodiment example is of a back contact type having a plus electrode and a minus electrode on the back surface.

[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, for example, a pair of electrodes 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.

This solar cell module 1 is manufactured by the following manufacturing method, for example.
That is, first, as shown in FIG. 4A, the stud bump 14 is formed on the electrode portion 12a of the circuit layer 12, that is, in the through hole 11a, and the stud bump 14 is formed on the electrode on the back surface of the solar battery cell 30. The solar battery cells 30 are arranged so as to face each other. And the laminated body which consists of these insulating substrates 10 for solar cells, the stud bump 14, and the photovoltaic cell 30 is heat-pressed. Thereby, the solar cell 30 electrically connected to the circuit layer 12 through the through-hole 11a is mounted on the insulating material 11 in the solar cell insulating substrate 10.

  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 of the solar battery cell 30 and the stud bump 14 can be electrically connected more easily.

  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. Thereafter, as shown in FIG. 4C, the barrier layer 13 is integrally fixed so as to cover the circuit layer 12 from the back surface side of the insulating material 11. Finally, the translucent substrate 20 is integrally fixed to the surface of the sealing layer 40, whereby the solar cells 30 arranged on the surface side of the insulating material 11 are made of the insulating material 11 as shown in FIG. 3. The solar cell module 1 electrically connected in series by the circuit layer 12 disposed on the back surface side can be obtained.

  According to the solar cell module 1 having such characteristics, since the solar cell insulating substrate 10 is mounted, it is possible to prevent warping in the insulating material 11. Therefore, a failure due to the warpage can be avoided, and maintenance performance can be improved.

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 substrate 10 according to the embodiment is composed only of the insulating material 11 and the circuit layer 12, but the insulating layer 11 and the circuit layer are provided with the barrier layer 13 and the stud bump 14 from the beginning. 12, the back sheet | seat which consists of the barrier layer 13 and the stud bump 14 may be comprised.

  In addition, in the solar cell insulating substrate 10, an overcoat layer that covers the back side of the circuit layer 12 may be provided. 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, a short circuit between adjacent circuit layers 12 can be prevented.

  Furthermore, as a manufacturing method of the insulating substrate 10 for solar cells, the procedure shown in FIG. 5 may be used, for example. That is, first, as shown in FIG. 5A, the concavo-convex structure B is formed on the surface of the metal foil 18 made of a metal such as copper, aluminum, iron-nickel alloy or the like. In parallel with this step, as shown in FIG. 5B, a step of forming a through hole 11a in the semi-cured composite material layer 19 is performed.

  And as shown in FIG.5 (c), it laminated | stacks so that the uneven structure B of the metal foil 18 may contact the back surface of the semi-hardened composite material layer 19, and then, as shown in FIG.5 (d), semi-hardened The surface of the metal foil 18 is pressure-bonded to the back surface of the semi-cured composite material layer 19 by subjecting the composite material layer 19 and the metal foil 18 to heat vacuum bonding.

  At this time, the back surface of the semi-cured composite material layer 19 is deformed according to the shape of the uneven structure B on the surface of the metal foil 18, so that the uneven structure B on the surface of the metal foil 18 is transferred to the back surface of the semi-cured composite material layer 19. The At the same time, the semi-cured composite material layer 19 is thermally cured to become the insulating material 11. Then, a circuit pattern 12 is formed by forming a resist pattern on the back surface of the metal foil 18 and performing an etching process. The solar cell insulating substrate 10 shown in FIG. 1 can be obtained.

  Thus, when the through-hole 11a is formed in the semi-cured composite material layer 19 in advance, unlike the case where the through-hole 11a is formed after the semi-cured composite material layer 19 is cured to form the insulating material 11, the cutting process is performed. At this time, it is not necessary to stop the circuit layer 12 so that a laser or a drill does not hit. Therefore, the through hole 11a can be easily formed.

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

Claims (6)

An insulating material having a plate shape made of a composite material containing fibers and a resin and having solar cells arranged on the surface;
A circuit layer laminated on the back surface of the insulating material and electrically connected to the solar cell through a through hole formed in the thickness direction of the insulating material;
An insulating substrate for a solar cell, wherein an uneven structure is formed on the back surface of the insulating material.   The insulating substrate for a solar cell according to claim 1, wherein a value of the maximum height Rmax of the concavo-convex structure is set to a value of 10% or more of a thickness dimension of the insulating material. The uneven structure is
3. The sun according to claim 1, wherein triangular prisms extending in one direction along the back surface of the insulating material are continuously arranged in a direction orthogonal to the one direction. Insulating substrate for battery. The uneven structure is
The insulating substrate for solar cells according to claim 1 or 2, wherein unit convex shapes having a quadrangular pyramid shape are two-dimensionally arranged along the surface direction of the back surface of the insulating material. . 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 battery module comprising a solar battery cell and a sealing resin for sealing the solar battery 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 4. Forming an uneven structure on the surface of the metal foil;
Laminating the surface of the metal foil on the surface of a semi-cured composite material layer containing fibers and a thermosetting resin;
Subjecting the laminated metal foil and the semi-cured composite material layer to heat and pressure treatment, and making the semi-cured composite material layer an insulating material;
And a step of patterning the metal foil to form a circuit layer,
The method for producing an insulating substrate for a solar cell, further comprising a step of forming, in the semi-cured composite material layer or the insulating material, a through hole that exposes a part of the circuit layer to the light receiving surface side.

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