JP2001339089A - Solar battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar battery module capable of solving such a problem that the module cannot be harmonized with the environment of the surroundings because a wiring member of a solar battery module for power generation has metallic gloss. SOLUTION: In the solar battery module in which a plurality of solar battery cells are arranged and are connected by a wiring member, the surface of the wiring member is coated with a resin layer whose surface is colored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solar cell module, and more particularly to a solar cell module in which a plurality of solar cells are connected by wiring members.

[0002]

2. Description of the Related Art Solar cells are classified into two types depending on the intended use. 2. Description of the Related Art Conventionally, a solar cell for consumer use has been often used as a portable power supply represented by a train, a clock, and the like.

[0003] However, solar cells used for electric power, such as those for houses and building walls, whose markets have been expanding in recent years, have a large electric power scale, and the solar cell itself has a much larger light receiving area. Nevertheless, since the purpose is for electric power, only the photoelectric conversion efficiency has been emphasized, and less emphasis has been placed on the appearance of cells and modules.

[0004] However, solar cells for electric power are installed outdoors, and are tilted so that sunlight is incident on the solar cells. Harmonious installation was required.

A solar cell module generally has a structure in which a plurality of solar cells are connected by a lead wire, the periphery thereof is covered with a resin layer, and sandwiched between a glass on the front surface and a weather-resistant resin called a back sheet on the back surface. ing. Since the surface of the light receiving surface is made of glass, the solar cell and the wiring member are clearly visible.

FIG. 7 is a diagram showing a conventional solar cell module. In FIG. 7, 2 indicates a module frame, 3 indicates a wiring member, and 4 indicates a solar cell. In order to produce a module, a plurality of solar cells 4 are connected by wiring members 3. For this connection, a wiring material in which a copper foil is covered with solder is usually used.

FIG. 8 is a diagram showing a conventional wiring member. In FIG. 8, reference numeral 5 denotes a copper foil as a base portion of a wiring member, and reference numeral 6 denotes a coated solder layer. FIG. 9 shows an example of a conventional solder coating method. In FIG. 9, reference numeral 8 denotes a copper foil material before solder coating, 9 denotes solder, and 10 denotes a solder bath. In the conventional method, the copper foil 5 is formed so that both surfaces of the copper foil 5 are continuously coated with the solder 6.
Therefore, in the structure of the conventional wiring member 3, the solder 6 adheres to both the front and back surfaces of the copper foil 5. Therefore, as shown in FIG. 7, the wiring member 3 was conspicuous in the appearance of the module.

A solar cell is generally provided with an antireflection film so as to absorb light more, and is usually manufactured so as to be dark blue. On the other hand, as the wiring member 3 conventionally used in the solar cell module, a material obtained by applying a solder coating to a copper foil 5 is often used and has a metallic luster, so that light reflection is extremely large. As a result, the wiring member 3 becomes very Hitachi with respect to the surface of the solar cell 4, and the appearance as a module is not clean.
There was a problem that the environment with the surroundings could not be harmonized.

The present invention has been made in view of the above problems, and has been made in consideration of the conventional problem that the wiring material of a power solar cell module has a metallic luster, and the surroundings and the environment cannot be harmonized. It is an object to provide a solar cell module that has been eliminated.

[0010]

According to a first aspect of the present invention, there is provided a solar cell module in which a plurality of solar cells are arranged and connected by a wiring member. The surface of the wiring member is covered with a colored resin layer.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing an example of a solar cell used in the solar cell module according to the present invention. In FIG. 1, 1 is a semiconductor substrate, 1a is a surface uneven structure, 1
b is a light-receiving surface side impurity diffusion layer, 1c is a back surface side impurity diffusion layer (BSF), 1d is a surface antireflection film, 1e is a surface electrode,
1f indicates a back electrode.

The semiconductor substrate 1 is a monocrystalline or polycrystalline silicon substrate. This substrate may be either p-type or n-type. In the case of single crystal silicon, it is formed by a pulling method or the like, and in the case of polycrystalline silicon, it is formed by a casting method or the like. Polycrystalline gyricon can be mass-produced and is extremely advantageous over monocrystalline silicon in terms of manufacturing cost. An ingot formed by a pulling method or a casting method is sliced into a thickness of about 300 μm, and 10 cm × 1
The silicon substrate is cut into a size of about 0 cm or about 15 cm × 15 cm. The solar cell is manufactured using a monocrystalline or polycrystalline silicon substrate.

On the front side of the substrate 1, an uneven structure 1a for reducing the reflectance is usually formed. This is also for the purpose of removing damage during slicing. When monocrystalline silicon is used as the substrate 1, the uneven structure 1a forms a substantially uniform pyramid-shaped fine uneven structure called a texture structure. In the case where polycrystalline silicon is used as the substrate 1, a method of performing etching under the same conditions as texture etching of a single crystal substrate to partially form a texture or a similar structure is often used. Since the surface has various crystal plane orientations, the reflectivity cannot be sufficiently reduced. Therefore, a method of forming a concavo-convex structure by dry etching or mechanical etching without depending on the plane orientation has been studied.

On the surface side of the semiconductor substrate 1, a layer 1b in which a semiconductor impurity of the opposite conductivity type is diffused is formed. The layer 1b in which the opposite conductivity type semiconductor impurity is diffused is provided for forming a semiconductor junction in the silicon substrate 1. For example, when diffusing an n-type impurity, POCl _{3 is used.}
, A coating diffusion method using P ₂ O ₅ , and an ion implantation method for directly diffusing P ⁺ ions.

On the front side of the silicon substrate 1, an antireflection film 1d is formed. The anti-reflection film 1d is provided to prevent light from being reflected on the surface of the silicon substrate 1 and to effectively take light into the silicon substrate 1. The antireflection film 1d is made of a material having a refractive index of about 2 in consideration of a refractive index difference from the silicon substrate 1 and the like, and has a thickness of 500
Silicon nitride film or silicon oxide (S
iO ₂ ) film.

It is desirable to form a layer 1c in which one conductivity type semiconductor impurity is diffused at a high concentration on the back side of the silicon substrate 1. The layer 1c in which the one-conductivity-type semiconductor impurity is diffused at a high concentration forms an internal electric field on the back surface side of the silicon substrate 1 in order to prevent a decrease in efficiency due to carrier recombination near the back surface of the silicon substrate 1. is there. That is,
As a result of the carriers generated near the back surface of the silicon substrate 1 being accelerated by this electric field, power is effectively extracted, and in particular, the long-wavelength photosensitivity is increased and the deterioration of solar cell characteristics at high temperatures can be reduced.

On the front side of the silicon substrate 1, a surface electrode 1
e is formed. The surface electrode 1e is formed, for example, by screen printing and baking an Ag paste mainly composed of Ag powder, a binder, a frit, etc., and forming a solder layer thereon. The surface electrode 1e has a width of, for example, 200 μm.
And a large number of finger electrodes formed at a pitch of about 3 mm, and two bus bar electrodes interconnecting the large number of finger electrodes.

On the back side of the silicon substrate 1, a back electrode 1
f is formed. The back electrode 1f is also, for example, A
g paste and further form a solder layer.

FIG. 2 shows a part of a sectional structure of a solar cell module showing one embodiment according to the present invention. In FIG. 2, 1g denotes a light receiving surface side glass, 1h denotes an EVA, 1j denotes a back sheet, and 1i denotes a solar cell.

FIG. 3 and FIG. 4 are external appearance examples of a solar cell module showing an embodiment according to the present invention. 3 and 4, reference numeral 2 denotes a module frame, 3 denotes a wiring member, and 4 denotes a solar cell. In FIG. 3, the back sheet of the module is colored white, and in FIG. 4, the pack sheet of the module is colored. In order to manufacture a module, a plurality of Taiyo battery cells 4 are connected by wiring members 3. For this connection, a wiring material in which copper foil is coated with solder is usually used.

FIG. 5 shows an example of the structure of the wiring member used in the present invention. In FIG. 5, reference numeral 5 denotes a copper foil as a base portion of a wiring member, 6 denotes a covered Hirata layer, and 7 denotes a resin layer functioning as a solder resist. By using the colored resin layer 7, the appearance of the module can be made such that the gloss of the wiring member 3 is not noticeable.

As such a resin layer 7, a solder resist is suitably used, and other thermosetting resins such as epoxy resin, phenol resin, melamine resin, polyester resin, or silicone resin, or photo-setting resin Resin is used.

Since the resin layer 7 is colored, the gloss of the wiring member 3 can be reduced. For example, since the color of a solder resist is quite dark, its thickness is 2-3.
Although the gloss of the wiring member 3 can be reduced even with a thickness of about μm, considering the strength and the post-process of the solar cell module, it is 15 to 20 μm.
The thickness is preferably about m.

FIG. 6 shows an embodiment of the method of coating the wiring member 3 with the solder 6 and the solder resist 7 according to the present invention. 6, reference numeral 11 denotes a heater, and 12 denotes a solder resist coating device. In the present invention, the method of applying the solder resist 7 does not matter. When a thermosetting solder resist 7 is used, the applied solder resist 7 is then heated and dried by a heater, and then enters a solder bath and is covered with the solder 6 only on the side where the solder resist 7 is not attached. .

As described above, by manufacturing a module using the wiring member 3 manufactured by the method of manufacturing the wiring member 3 according to the present invention, the wiring member 3 can have an inconspicuous appearance when viewed from the surface. Becomes

[0026]

As described above, according to the Taiyo battery module according to the present invention, the surface of the wiring member for connecting a plurality of solar cells is covered with the colored resin layer, so that the wiring member stands out. It is possible to provide a module with excellent aesthetics, and to achieve harmony with the surrounding environment.

[0027]

[Brief description of the drawings]

FIG. 1 is an outline view showing a structure of a solar cell required for producing a solar cell module according to the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a structure of a solar cell module according to the present invention.

FIG. 3 is a diagram showing an external appearance of an example of a solar cell module according to the present invention.

FIG. 4 is a diagram showing an external appearance of an example of a solar cell module according to the present invention.

FIG. 5 is a diagram showing a cross-sectional structure of a wiring member of the module according to the present invention.

FIG. 6 is a diagram showing an example of a method for producing a wiring material of a module according to the present invention.

FIG. 7 is a view showing the appearance of a conventional solar cell module.

FIG. 8 is a diagram showing a cross-sectional structure of a wiring member in a conventional module.

FIG. 9 is a diagram showing an example of a method for manufacturing a wiring material of a conventional module.

[Explanation of symbols]

1: substrate, 1a: surface uneven structure, 1b: impurity diffusion layer,
1c: back surface diffusion layer, 1d: antireflection film, 1e: front electrode, 1f: back electrode, 1g: glass, 1h: EVA, 1
i: solar cell, 1j: back sheet, 2: aluminum frame, 3: lead wire, 4: solar cell, 5: copper foil, 6:
Solder, 7: Resist material, 8: Copper foil material before metal coating,
9: Solder, 10: Solder bath, 11: Heater, 12: Resist coating device

Claims (1)

[Claims] 1. A solar cell module comprising a plurality of solar cells arranged and connected by a wiring member, wherein the surface of the wiring member is covered with a colored resin layer.