JP2011238849A - Solar cell module circuit sheet, solar cell module, and method of manufacturing solar cell module circuit sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module circuit sheet capable of avoiding a problem such as a short circuit of a circuit pattern and the filling failure of sealing material in a clearance of the circuit pattern, and stably mounting a solar battery cell of a back contact system.SOLUTION: The solar cell module circuit sheet 10 is composed of an insulation layer 11 made from insulating resin; a barrier layer 13 arranged on a rear surface side of the insulation layer 11, and having a steam barrier property, an oxygen barrier property, and an insulating property; and a metal conductive layer 12 arranged on a front surface side of the insulation layer 11, and having the circuit pattern electrically connected to the solar battery cell. The metal conductive layer 12 is buried in a surface of the insulation layer 11, and the surfaces of the metal conductive layer 12 and the insulation layer 11 are positioned on the same plane.

Description

  The present invention relates to a circuit sheet for a solar cell module used for fixing a back contact type solar cell having both a positive electrode (P-type semiconductor electrode) and a negative electrode (N-type semiconductor electrode) on the back surface, and It relates to the manufacturing method.

  In recent years, solar power generation, which is a power generation system using natural energy, has been rapidly spread. As shown in FIG. 6, a solar cell module for photovoltaic power generation includes a light-transmitting substrate 202 disposed on the light receiving side, a back sheet 201 disposed on the back surface side, a light-transmitting substrate 202 and a back. A large number of solar cells 203 are arranged between the sheets 201. The solar battery cell 203 is sealed by being sandwiched between sealing materials 204 such as an ethylene / vinyl acetate copolymer (EVA) film.

  Conventionally, in a solar cell module, a large number of solar cells 203, 203... Are electrically connected in series with a wiring member 205 having a width of 1 to 3 mm. Since the solar battery cell 203 is provided with a negative electrode (N-type semiconductor electrode) on the front surface side which is a light receiving surface of the sun and a positive electrode (P-type semiconductor electrode) on the back surface side, The wiring member 205 overlaps the light receiving surface of the battery cell 203, and the area efficiency of photoelectric conversion tends to be reduced. Furthermore, since the wiring member 205 has a structure that wraps around from the front side to the back side of the solar battery cell 203, the wiring member 205 may be disconnected due to a difference in thermal expansion of each member.

  In order to solve these problems, for example, Patent Documents 1 and 2 propose a back-contact type solar cell in which both a positive electrode and a negative electrode are installed on the back surface of the cell. In the solar cell of this system, it is possible to connect in series on the back surface of the cell, and the light receiving area on the cell surface is not sacrificed, and the reduction of the area efficiency of photoelectric conversion can be prevented. Moreover, since it is not necessary to make the wiring material go around 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.

  When a solar cell module is manufactured using this back contact type solar cell, a large number of solar cells are electrically connected in series using a circuit sheet and then sealed with an EVA film. And was held between the translucent substrate and the back sheet.

  Here, the manufacturing method of the circuit sheet for typical back contact type solar cells is explained. First, a film such as polyethylene terephthalate or polyethylene naphthalate is used as an insulating layer, and a copper foil is bonded thereto using an adhesive. Next, a resist is formed on the copper foil, and etching is performed using the resist as a mask to form a metal conductive layer having a circuit pattern. And the circuit sheet by which the metal conductive layer by copper was laminated | stacked on the insulating layer is completed by peeling the resist used as the mask.

  Thereafter, a bonding paste is applied to the solar cell joints on the circuit sheet, the solar cells are mounted, and the solar cells are sealed with a sealing material and glass to complete the solar cell module. .

JP 2009-111122 A JP 2009-224597 A

However, in the above-described conventional technology, when the back contact solar cell is mounted, the bonding paste flows into the gap (wiring gap) between the circuit patterns of the metal conductive layer, which may cause a short circuit between the circuit patterns. was there.
Further, when the solar battery cell is sealed after being mounted, there is a risk that a filling failure of the sealing material occurs in the wiring gap of the metal conductive layer, resulting in cracks and the like.
Furthermore, due to the difference in thermal expansion coefficient between the sealing resin and the insulating layer, there is a problem in that the solar battery module is distorted after the solar battery is sealed, and the solar battery is frequently cracked and peeled off.

  The present invention has been made in view of such problems, and can avoid problems of short circuit patterns and poor filling of the sealing material in the gaps between the circuit patterns. It aims at providing the manufacturing method of the circuit sheet for solar cell modules which can be mounted stably, a solar cell module, and the circuit sheet for solar cell modules.

In order to solve the above problems, the present invention proposes the following means.
That is, the solar cell module circuit sheet according to the present invention includes an insulating layer made of an insulating resin, a barrier layer disposed on the back side of the insulating layer, having a water vapor barrier property, an oxygen barrier property, and an insulating property, A metal conductive layer disposed on the surface side of the insulating layer and disposed on the surface side of the insulating layer and having a circuit pattern electrically connected to the solar battery cell, wherein the metal conductive layer is the insulating layer The surface of each of the metal conductive layer and the insulating layer is located on the same plane.

  According to the solar cell module having such a feature, the metal conductive layer is buried in the surface of the insulating layer, that is, the gap between the circuit patterns of the metal conductive layer is filled with the insulating resin. It can prevent that the paste for joining for connecting a photovoltaic cell flows into the gap | interval of a circuit pattern.

Moreover, in the solar cell module which concerns on this invention, it is preferable that the said insulating layer is comprised from the same kind of resin as sealing resin which seals the said photovoltaic cell in the surface side of this insulating layer.
Thereby, since the thermal expansion coefficients of the insulating layer and the sealing resin are the same, the stress applied to the entire solar cell module can be relaxed, and a highly reliable solar cell module after cell sealing is manufactured. Can do.

  The solar cell module according to the present invention includes a translucent substrate disposed on the light receiving surface side, a solar cell module circuit sheet disposed on the back surface side of the translucent substrate, the translucent substrate, and the sun. A solar cell module comprising solar cells disposed between battery module circuit sheets and a sealing resin for sealing the solar cells, wherein the solar cell module circuit sheet is employed. It is characterized by that.

  As a result, it is possible to prevent the bonding paste for connecting the solar cells from flowing into the gaps between the circuit patterns, thereby preventing electrical shorts between the circuit patterns and poor filling of the sealing resin. The reliability of the module can be improved.

The method for producing a solar cell module circuit sheet according to the present invention includes a step of forming a metal conductive layer having a circuit shape by laminating a metal foil on a flat carrier film and patterning the metal foil. A step of forming an insulating layer by filling an insulating resin on the metal conductive layer and a gap in a pattern shape of the metal conductive layer, and a barrier having a water vapor barrier property, an oxygen barrier property, and an insulating property on the insulating layer It has the process of forming a layer, and the process of removing the said carrier film, It is characterized by the above-mentioned.
By passing through such a process, it becomes possible to manufacture the said solar cell module circuit sheet easily and reliably.

  According to the solar cell module of the present invention, it is possible to prevent the bonding paste for connecting the solar cells from flowing into the gaps in the circuit pattern, so that when the solar cells are mounted due to the bonding paste. Short circuit between circuit patterns can be prevented. Similarly, filling failure of the sealing resin in the gap between the circuit patterns of the metal conductive layer can be prevented. it can. Therefore, it is possible to stably mount the back contact solar cell.

It is a cross-sectional schematic diagram of the circuit sheet for solar cell modules of embodiment of this invention. It is a figure explaining the manufacturing method of the circuit sheet for solar cell modules of embodiment of this invention. It is a cross-sectional schematic diagram of the solar cell module of the embodiment of the present invention. It is a figure explaining the manufacturing method of the solar cell module of embodiment of this invention. It is a figure explaining the manufacturing method of the circuit sheet for solar cell modules in an Example. It is a cross-sectional schematic diagram of the conventional solar cell module.

Hereinafter, the embodiment of the circuit sheet for solar cell modules of the present invention is described.
The circuit sheet for solar cell modules of this embodiment is shown in FIG. This circuit sheet 10 for a solar cell module includes an insulating layer 11, a metal conductive layer 12 provided on the surface side of the insulating layer 11, and a barrier layer 13. A so-called back contact solar cell 30 is provided. Used for connection.

  The insulating layer 11 is a plate-like member made of epoxy resin, acrylic resin, ethylene vinyl acetate, ionomer, or the like, and is preferably formed from the same resin as the sealing resin 40 described later. The surface of the insulating layer 11 (the surface facing the upper side in FIG. 1) is preferably subjected to a hydrophobic treatment.

  The metal conductive layer 12 is a layer that is electrically connected to an electrode of the solar battery cell 30 described later, and is laminated on the surface side of the insulating layer 11. The metal conductive layer 12 has a circuit pattern that electrically connects the electrodes of the solar cells 30 stacked on the solar cell module circuit sheet 10 in series. For this reason, it does not cover the entire surface of the insulating layer 11, but has a gap that exposes the surface of the insulating layer 11 to the light receiving surface according to the shape of the circuit pattern.

As a material constituting the metal conductive 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.
Further, in this embodiment, the metal conductive layer 12 is buried in the surface of the insulating layer 11, whereby the metal conductive layer 12 and the surface of the insulating layer 11 are arranged on the same plane, that is, the metal conductive layer. The surfaces of the layer 12 and the insulating layer 11 are flush with each other.

  The barrier layer 13 is laminated on the back side of the insulating layer 11 and is made of a material having long-term reliability such as water vapor barrier properties, oxygen barrier properties, and insulation properties. Examples of the material include polyethylene terephthalate resin, polyethylene naphthalate resin, fluorine-based resin film, aluminum, alumina, silica, and the like, and the barrier layer 13 is formed by bonding two or more kinds of films made of these materials.

Next, the manufacturing method of the said circuit sheet 10 for solar cell modules is demonstrated.
In the manufacturing method of the solar cell module circuit sheet 10 according to this embodiment, first, as shown in FIG. 2A, a metal foil 102 is bonded to the upper surface of a carrier film 101 having a flat shape. This carrier film 101 is a film that is used only in the manufacturing process, and examples of the material include polyethylene terephthalate resin, polyethylene naphthalate resin, polyimide, etc., but polyethylene naphthalate resin should be adopted from the viewpoint of thermal history and the like. Is preferred.

  Moreover, it is preferable that the bonding surface with the carrier film 101 in the metal foil 102 is subjected to an easy adhesion treatment. Of course, the metal foil 102 preferably has a thickness of about 10 μm to 100 μm.

  Next, as shown in FIG. 2B, the metal foil 102 is patterned to form a metal conductive layer 12 having a circuit pattern. Specifically, a resist mask pattern is formed on the metal foil 102 by printing, a photofabric method, or the like, and then an unnecessary portion of the metal foil 102 is removed by performing an etching process. Then, the metal conductive layer 12 can be obtained by removing the resist mask pattern. The surface of the metal conductive layer 12 is preferably subjected to a surface roughening treatment with a corrosive chemical such as formic acid, sulfuric acid or nitric acid in order to improve the adhesion to the bonding paste 14 described later.

  Thereafter, as shown in FIG. 2C, the metal conductive layer 12 is sealed with the insulating layer 11. Specifically, the insulating layer 11 is formed on the surfaces of the metal conductive layer 12 and the carrier film 101 so that the insulating resin is filled in the gaps between the circuit patterns in the metal conductive layer 12 and in the metal conductive layer 12.

  Subsequently, as shown in FIG. 2D, a barrier layer 13 is pasted on the insulating layer 11, and thereafter, as shown in FIG. 2E, the carrier film 101, the insulating layer 11, the metal conductive layer 12, and the barrier. The circuit sheet 10 for solar cell modules can be obtained by inverting the laminate composed of the layers 13 upside down and peeling off the carrier film 101.

The solar cell module circuit sheet 10 is used in a solar cell module. FIG. 3 shows a solar cell module using the solar cell module circuit sheet 10.
This solar cell module 1 seals the solar cell module circuit sheet 10 disposed on the back surface side, the solar cell 30 disposed on the solar cell module circuit sheet 10, and the back surface side of the solar cell 30. The sealing resin 40 and the translucent board | substrate 20 laminated | stacked on the sealing resin 40 are provided. Moreover, in this embodiment, in order to fix the photovoltaic cell 30 to the circuit sheet 10 for solar cell modules, the joining paste 14 is used.

  The bonding paste 14 is a member that assists in electrical connection between the metal conductive layer 12 and the solar battery cell 30. As the material of the bonding paste 14, a material having a low electric resistance is used. Especially, since the electrical resistance with the metal conductive 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, gold | metal | money, and bismuth. Furthermore, since this bonding paste 14 has a high viscosity and can be easily formed into a desired shape, it is at least one selected from the group consisting of silver, copper, tin, and solder (copper and lead are the main components). It is preferable to contain a metal.

  The sealing resin 40 is formed of a sealing film. As the sealing film, for example, an EVA sheet, an ethylene / (meth) acrylic acid ester copolymer film, a fluororesin film such as polyvinylidene fluoride, etc. are generally used. In this embodiment, the EVA sheet is used. Is adopted. Usually, two or more sealing films are used so as to sandwich the solar battery cell 30 therebetween.

  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.

  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 a positive electrode and a negative electrode on the back surface side.

  Here, the solar cell 30 is mounted on the solar cell module circuit sheet 10, as shown in FIG. 4A, first, the bonding paste 14 is applied onto the metal conductive layer 12 of the solar cell module circuit sheet 10. Deploy. Next, the solar battery cell 30 is arranged so that the bonding paste 14 faces the electrode formed on the back surface of the solar battery cell 30, and further, the solar cell module circuit sheet 10, the bonding paste 14 and the solar battery cell. The laminated body made of 30 is heated and pressurized to integrate the solar battery module circuit sheet 10 and the solar battery cell 30 shown in FIG.

  As a method for forming the bonding paste 14, for example, methods such as plating, screen printing, dispensing, and transfer can be applied. 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.

  And as shown in FIG.4 (c), this solar cell 30 is sealed with the sealing resin 40 so that the solar cell 30 may be covered from the circumference | surroundings on the surface side of the circuit sheet 10 for solar cell modules, As shown in FIG. 4 (e), the translucent substrate 20 is disposed on the front surface side of the sealing resin 40 and the barrier layer 13 is formed on the back surface of the circuit sheet 10 for the solar cell module. The solar cell module 1 can be obtained.

  According to the solar cell module circuit sheet 10 and the solar cell module 1 having the above characteristics, the metal conductive layer 12 is buried in the surface of the insulating layer 11, that is, the metal conductive layer 12 is insulated in the gap of the circuit pattern. Since it is set as the structure filled with the layer 11, it can prevent that the paste 14 for joining for connecting the photovoltaic cell 30 flows in into the clearance gap between circuit patterns. Thereby, a short circuit between circuit patterns when the solar battery cell 30 is mounted due to the bonding paste 14 can be prevented, and filling failure of the sealing resin 40 in the gap between the circuit patterns of the metal conductive layer 12 can be prevented. Therefore, it is possible to stably mount the back contact solar cell 30.

  Moreover, in the solar cell module 1, the insulating layer 11 of the solar cell module circuit sheet 10 is made of the same type of resin as the sealing resin 40 that seals the solar cells 30 on the surface side of the insulating layer 11. Therefore, the thermal expansion coefficients of the insulating layer 11 and the sealing resin 40 are the same. Therefore, the stress concerning the whole solar cell module 1 can be relieved, and the solar cell module 1 with high reliability after sealing the solar cell 30 can be produced.

  Furthermore, according to the manufacturing method of the solar cell module circuit sheet 10 of the present embodiment, the metal foil 102 is laminated on the carrier film 101, and the metal foil 102 is subjected to pattern processing to have a circuit pattern. Further, by filling the gap between the metal conductive layer 12 and the circuit pattern of the metal conductive layer 12 with an insulating resin, the solar cell module circuit sheet 10 having the above-described configuration can be easily manufactured. As a result, the production efficiency can be improved and the cost can be reduced.

  As mentioned above, although embodiment of this invention was described in detail, unless it deviates from the technical idea of this invention, it is not limited to these, A some design change etc. are possible.

Hereinafter, the Example of the circuit sheet 10 for solar cell modules and the solar cell module 1 of this invention is described concretely.
First, as shown in FIG. 5 (a), a 35 μm thick copper foil (trade name: JTC copper foil, manufactured by Nikko Metal) as a metal foil 102 on a carrier film 101 (trade name: Teonex, manufactured by Teijin DuPont). Affixed. Next, a dry film resist 103 (trade name: RY3315, manufactured by Hitachi Chemical Co., Ltd.) was attached to the surface of the metal foil 102 using a roll laminator at a temperature of 110 ° C. and a conveyance speed of 0.5 m / min. . Thereafter, a resist pattern was formed by exposure using a photomask (exposure amount: 80 mJ / cm 2) and development (1 mass% Na 2 CO 3, temperature: 30 ° C.).

  Next, after etching the exposed metal foil 102 with copper chloride (temperature: 50 ° C.), the resist pattern is peeled off at 50 ° C. with a 5 mass% aqueous sodium hydroxide solution as shown in FIG. Then, a metal conductive layer 12 having a circuit pattern was formed.

  Thereafter, a 450 μm EVA film (trade name: SOLAR EVA, manufactured by Mitsui Chemicals Fabro) as the insulating layer 11 on the metal conductive layer 12, and a 25 μm thick ceramic vapor-deposited film (trade name: GL film, manufactured by Toppan Printing) as the barrier layer 13 ) Was laminated and heated and pressurized using a module laminator at a temperature of 150 ° C. and a vacuum holding time of 13 minutes to obtain a laminate. Finally, the carrier film 101 was peeled off to obtain a solar cell module circuit sheet 10.

  Then, the solar cell module 1 was produced using the circuit sheet 10 for solar cell modules produced as mentioned above. Specifically, first, Sn / Bi solder (trade name: ECO SOLDER M42, manufactured by Senju Metal) was applied as a bonding paste 14 on the metal conductive layer 12 by screen printing. After that, an EVA film (product name: SOLAR EVA, manufactured by Mitsui Chemicals Fabro Co., Ltd.) in which a connection portion between the bonding paste 14 and the solar battery cell 30 is opened between the solar cell module circuit sheet 10 and the solar battery cell 30. 40a is laminated, and an EVA film (trade name: SOLAR EVA, manufactured by Mitsui Chemicals Fabro) 40b is laminated on the surface side of the solar battery cell 30. Then, a 3.2 mm thick glass (manufactured by AGC Fabricec) is laminated as the translucent substrate 20, and heated and pressurized using a module laminator at a temperature of 150 ° C. and a vacuum holding time of 13 minutes. As a result, the EVA films 40a and 40b were integrated into the sealing resin 40, and the solar cell module 1 in which the solar cells 30 were sealed with the sealing resin 40 was obtained (FIG. 5E).

DESCRIPTION OF SYMBOLS 10 Circuit sheet 11 for solar cell modules Insulating layer 12 Metal conductive layer 13 Barrier layer 14 Bonding paste 20 Translucent substrate 30 Solar cell 40 Sealing resin 40a EVA film 101 Carrier film 102 Metal foil 103 Dry film resist

Claims (4)

An insulating layer made of insulating resin;
A barrier layer disposed on the back side of the insulating layer, having a water vapor barrier property, an oxygen barrier property, and an insulating property;
A metal conductive layer disposed on the surface side of the insulating layer and having a circuit pattern electrically connected to a solar battery cell;
The circuit sheet for a solar cell module, wherein the metal conductive layer is buried in the surface of the insulating layer, and the surfaces of the metal conductive layer and the insulating layer are located on the same plane.   The said insulating layer is comprised from the resin of the same kind as sealing resin which seals the said photovoltaic cell in the surface side of this insulating layer, The circuit sheet for solar cell modules of Claim 1 characterized by the above-mentioned. . A translucent substrate disposed on the light-receiving surface side;
A circuit sheet for a solar cell module disposed on the back side of the translucent substrate;
A solar battery cell disposed between the translucent substrate and the solar cell module circuit sheet;
A solar cell module comprising a sealing resin for sealing the solar cell,
The solar cell module circuit sheet according to claim 1 or 2, wherein the solar cell module circuit sheet is the solar cell module circuit sheet. Laminating a metal foil on a flat carrier film, patterning the metal foil to form a metal conductive layer having a circuit pattern;
Filling an insulating resin in the gap between the metal conductive layer and the circuit pattern of the metal conductive layer to form an insulating layer;
Forming a barrier layer having water vapor barrier property, oxygen barrier property and insulating property on the insulating layer;
And a step of removing the carrier film. A method for producing a circuit sheet for a solar cell module.

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