JPH03239377A - Solar cell module - Google Patents

Abstract

PURPOSE:To simplify production process, reduce the cost and improve shock resistance by arranging a plurality of solar cell elements to be formed on a conductive substrate on an insulating substrate and forming a connection with collecting electrode using conductive paste. CONSTITUTION:A plurality of solar cell elements 101 are densely and adjacently arranged on an insulating substrate 100 and the solar cell elements 101 edges, on which wiring 105 passes so as to connect each solar cell element 101 electrically, are coated with insulating resin 103. Then, a collecting electrode 104 on a transference electrode 110 and the connecting wiring 105 which connects the solar cell elements 101 adjacent to each other are formed by conductive paste on a plane on which light is made incident. In such a manner, the collecting electrode 104 and the connecting wiring 105 for integration are simultaneously formed on one side. Thus, production process is simplified, the cost is reduced and shock resistance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solar cell module in which solar cell elements formed on a plurality of conductive substrates are integrated.

[Prior Art] Recently, it has been predicted that the increase in CO2 will lead to global warming due to the greenhouse effect, and the demand for clean energy is increasing. Additionally, there are voices questioning the safety of nuclear power generation, which does not emit CO□, and there is a desire for safer, cleaner energy.

Among the clean energy sources expected in the future, solar cells are particularly promising because of their cleanliness, safety, and ease of handling.

Among various types of solar cells, amorphous silicon, copper insium selenide, etc. have been actively researched because they can be manufactured in large areas and their manufacturing costs are low.

Furthermore, among solar cells, when impact resistance and flexibility are required, a metal substrate such as stainless steel is used as the substrate material. In order to integrate solar cells using conductive substrates to produce a desired electromotive force, it has conventionally been necessary to directly wire a plurality of solar cell elements. FIG. 4 is a schematic diagram of a conventional example in which a plurality of solar cell elements are wired in series using wiring materials. In FIG. 4, 400 is a conductive substrate;
401 is a lower electrode, 402 is a semiconductor layer, 403 is an upper electrode, 404 is an integrated electrode, and 405 is a wiring material.

As an integration method, the method of connecting series wiring to solar cell elements connects and wires the current collecting electrode on the front side of adjacent solar cell elements and the conductive substrate on the back side, so it requires the process of front side connection and back side connection. As a result, automation of the manufacturing process was complicated and the connection process took time, making it impossible to reduce manufacturing costs even with mass production. Furthermore, since the wiring connections were on both the front and back sides, the surface became very uneven, and bubbles were likely to occur when the surface was coated.

Also, Japanese Patent Publication No. 58-21827 and Japanese Patent Publication No. 58-21827
No. 54513 proposes a method of integrating solar cell elements on the same insulating substrate by a method such as mask vapor deposition. As an application of the proposed method, after coating an insulating layer on a conductive substrate, a metal electrode pattern is sequentially formed using a method such as mask evaporation, and the transparent metal electrode of an adjacent solar cell subcell on the same substrate is formed. There are ways to connect the electrodes. Figure 5 is an example of a conventional configuration diagram in which solar cell elements are integrated on the same substrate by mask vapor deposition, (a) is a plan view, (b) is (a) Figure A
-B is a cross-sectional configuration diagram. In FIG. 5, 500 is a conductive substrate, 501 is an insulating layer, 502 is a lower electrode, 503 is a semiconductor layer, and 504 is a transparent electrode as a −L portion electrode.

In addition, methods such as mask evaporation to serially connect on the same substrate have difficulty in aligning the masks, resulting in poor yields when manufacturing large-area modules, and the ability to accommodate various required power capacities and arbitrary shapes. To do this, it is necessary to prepare many types of masks. In addition, unless the conductive substrate is covered with an insulating material without pinholes, the number of manufacturing steps required to take it apart increases, which inevitably increases costs.

[Object of the Invention] An object of the present invention is to solve the conventional drawbacks mentioned in -L and to provide an inexpensive integrated solar cell module that is resistant to impact.

[Structure and operation of the invention] As a result of intensive research in order to solve the above-mentioned conventional drawbacks, the present inventors arranged a plurality of solar cell elements formed on a conductive substrate on an insulating substrate, It has been found that inexpensive solar cell modules can be obtained by forming connections with current collecting electrodes using conductive pastes. The present invention relates to a solar cell module manufactured by connecting a plurality of solar cell elements in which a metal electrode layer, a semiconductor layer, and a transparent electrode layer are sequentially formed on a conductive substrate. The elements are arranged closely adjacent to each other with the expectation of insulation, and the end face of the solar cell element in the portion through which the arrangement for electrically connecting the solar cell elements passes is coated with an insulating resin, and a conductive paste is applied. This is a solar cell module characterized in that a current collecting electrode on a transparent electrode and connection wiring between the adjacent solar cell elements are formed on a light incident side surface.

The conductive paste is composed of a conductive resin, a cream solder, or a conductive resin and a cream solder. The conductive resin is made by adding conductive fillers such as metal powder, conductive carbon black, and carbon fiber to a polymer compound. Cream solder is made by mixing powder-H solder with highly viscous flux to form a cream.

Note that the current collecting electrode and wiring formed of the conductive paste may be reinforced with a good conductor.

FIG. 1 is an example of a schematic configuration diagram of a solar cell module manufactured according to the present invention. Figure 1 (a) is a plan view of an example of a solar cell module in which four solar cell elements are wired in series, (b) and (c) are cross-sectional views including mounting parts such as laminate, and (b) is a cross-sectional view taken along line AB in (a), and (c) is a cross-sectional view taken along line CD in (a). In FIG. 1, 100 is an insulating substrate, 102 is an exposed insulating substrate portion, and 103 is an insulating material 4! AII+r1
．． 104 and 105 are current collecting electrodes and wiring mainly formed by the smooth conductive hairs 1~, 106 is a conductive substrate, 107 is a transparent electrode layer/semiconductor layer/metal electrode layer, 111
112 is a filler, 112 is a surface protective layer, 113 is a metal foil, 11
4 is conductive adhesive or solder, 115 is a lead wire,
116 is a sealing material.

FIG. 2 is a schematic diagram of the solar cell element used in FIG. 1, in which (a) is a plan view thereof, and (b) is a sectional view taken along line E-F in (a). In Figure 2, 101, 102, 105
1, 108 is a metal electrode layer as a lower electrode, 109 is a semiconductor layer, and 110 is a transparent electrode as an upper electrode.

Furthermore, FIG. 3 shows an example of a schematic configuration diagram of a solar cell module of the present invention, which is manufactured by arranging a large number of solar cell elements formed on a conductive substrate and providing series wiring with a current collecting electrode. . In FIG. 3, 300 is an insulating substrate, 302 is an exposed insulating substrate portion, 303 is an insulating resin, and 304 and 305 are current collecting electrodes and wiring, respectively, formed mainly of conductive paste.

Although FIGS. 1 and 3 show the configuration of a module in which a plurality of solar cell elements are connected in series, the present invention is not limited thereto and can also be applied to cases in which they are connected in parallel.

An example of a method for manufacturing the solar cell module of the present invention shown in FIG. 1 will be sequentially explained.

First, a metal layer, a semiconductor layer, and a transparent electrode layer are formed on a conductive substrate and cut into a desired area size to obtain the solar cell element 101 shown in FIG. 2. A portion of the transparent electrode layer/semiconductor layer/metal layer at the end of the solar cell element shown in FIG. 2 is removed to expose the conductive substrate surface 102. There is no problem even if the metal layer remains on the exposed substrate surface at this time. Next, a filler l11 is spread on the surface of the insulating substrate 100, a hole is made in a portion where an output terminal extraction portion is to be provided, and a metal foil 113 that will become an output terminal is provided so as to cover the hole. A conductive adhesive or solder 114 is attached to a metal foil 113 provided directly above the conductive substrate of the solar cell element. Then, after arranging the solar cell elements with a part of the substrate surface exposed on the insulating substrate covered with the filling material, the required number of electromotive force (four in the case of Fig. 1) is applied. A part of the end face is covered with an insulating material 103. An insulating coating may be applied before arraying. Thereafter, a collected power 104 and a series wiring 105 are formed using a conductive paste. The collector electrode 104 and the wiring 105 formed of conductive paste may be reinforced with a good conductor.

By reinforcing it with a good conductor, the bending strength of the current collecting electrode and the connecting wiring section are matched, and power loss due to wiring resistance is also reduced.

Furthermore, a surface protection layer N112 is formed, the lead wire 115 is taken out from the output terminal 113, and the lead wire take-out portion is sealed with a sealing material 116 to obtain a solar cell module.

Note that the reason why the insulating material 103 is provided is to prevent the conductive substrate 106 of the solar cell element and the connection wiring 105 from coming into contact with each other and causing conduction.

In the above manufacturing method, a method of connecting the collector electrodes of adjacent solar cell elements and the exposed portion of the conductive substrate is used as a serialization method, or the following method is also available as another method. A region in which the transparent electrode layer is separated into an island shape is provided at the end of the solar cell element, and a connection wiring from the current collecting electrode of the adjacent solar cell element is formed in this region using a conductive base. Thereafter, the wiring formed in the area can be irradiated with laser light to melt it and connect it to the lower electrode for integration.

From the above description of the manufacturing method, it can be seen that the solar cell module having the structure of the present invention can be manufactured at a high yield and at low cost even with a large area without using a complicated wiring process.

The conductive resin used as the conductive paste used in the present invention is prepared by dispersing finely powdered silver, gold, copper, nickel, carbon, etc. with a pinter polymer. The above binder polymers include polyester, epoxy, acrylic, alkyd, polyvinyl acetate, rubber,
There are resins such as urethane and phenol. When a conductive resin and cream solder are used as the conductive paste, for example, when the solder is laminated on the conductive resin, In-based solder or solder containing metal in the conductive resin is suitable. This is to prevent the metal elements in the conductive resin from being corroded by the solder. In other words, when using silver paste for the conductive resin, In-based solder or silver-containing solder is suitable.

The current collecting electrodes and wiring are formed by applying a conductive paste in a predetermined pattern using a screen printer or dispenser, and then heat-treating the paste.

In order to deal with a wide variety of current collecting electrodes and wiring patterns,
Screen printing machines require a wide variety of printing plates that correspond to different patterns. Dispensers can be controlled easily by NC. Good conductors used for reinforcing the current collecting electrodes and connection wiring include foil-like or wire-like metals such as copper, aluminum, nickel, and silver, and carphone fibers. When a foil or wire metal is used, the reinforcing method is to bond the foil or wire metal onto the current collecting electrode and connection wiring formed of conductive paste using a conductive adhesive or solder.

Insulating materials used in the present invention include polyester, polyesterimide, polyurethane, silicone, epoxy, acrylic resin, and the like. The insulating material may be coated by spraying, screen printing, a dispenser, etc., or by pasting a resin film of the insulating material with an adhesive.

Examples of the filler used in the present invention include ethylene-vinyl acetate copolymer, polyvinyl acetate, and silicone resin.

1 The insulating substrate used in the present invention includes butyl rubber, a metal plate such as aluminum coated with an insulating resin, a fluororesin film such as polyvinylidene fluoride, polyester,
There are aluminum foils laminated with polyethylene and polypropylene resin films.

The surface protective layer used in the present invention must be transparent, stable against ultraviolet rays and ozone, and have a two-layer structure of fluororesin film/ethylene-vinyl acetate copolymer ( On the light incident side, examples include a fluororesin film), silicone resin, and fluororesin lighting material.

Sealing materials used in the present invention include silicone resins and butyl rubbers that do not allow moisture to pass through.

The conductive substrate of the solar cell element used in the present invention includes stainless steel, aluminum, copper, carbon sheet, and the like. The material of the metal electrode layer includes Ti, Tr, Mo, W,
Ai, Ag.

Ni etc. are used, and the forming method is resistance heating 2 Vapor deposition, electron beam evaporation, sputter link method, etc. are available.

Examples of the semiconductor layer as a photoelectric conversion member of the solar cell element used in the present invention include pin junction amorphous silicon, Pn junction polycrystalline silicon, and compound semiconductors such as Cu1nse2/CdS. In the case of amorphous silicon, the semiconductor layer is formed by plasma CVD using silane gas, etc. In the case of polycrystalline silicon, the semiconductor layer is formed by forming a sheet of molten silicon (:ul
In the case of nse2/CdS, it is formed by methods such as electron beam evaporation, sputter linking, and electrodeposition (deposition by electrolysis of an electrolytic solution).

Materials used for the transparent electrode of the solar cell element used in the present invention include In2(]+, 5nOz, In2O
:+-3no2. ZnO, Tie□, Cd2SnO
4. There is a crystalline semiconductor layer etc. doped with high concentration impurities,
Formation methods include resistance heating evaporation, electron beam evaporation, sputtering, spraying, CVD, and impurity diffusion.

[Examples] Hereinafter, the present invention will be described in detail based on Examples. In addition,
The present invention is not limited to these examples.

In this example, a procedure for manufacturing a module having the configuration shown in FIGS. 1 and 2 in the case of an amorphous silicon solar cell using a stainless steel substrate as a conductive substrate will be specifically explained.

First, A I 10 containing 1% Si was deposited on the cleaned rolled stainless steel substrate 106 by a roll-to-roll method.
8 was deposited to a thickness of 5000A by sputtering, and SiH<
, PH3, 82116, H2 gas, etc. plus VCVD
As a result, a Pin amorphous silicon layer 1 with a film thickness of 4000A was formed.
After forming 09, ITOIIO with a thickness of 800 Å was formed by resistance heating vapor deposition. Furthermore, ITO etching agent (Fe
A portion of the ITO layer was removed by screen printing a paste containing C1,...HCI) and separated into each solar cell element.

Next, the ITOI located at the wiring connection part of each solar cell element
After the amorphous silicon layer 109 of the IO/Pin was removed using a clinter to expose the substrate surface 102, the ITO removed portion was irradiated with a YAG laser beam and cut to obtain a plurality of solar cell elements 101. Then, EV was applied to the butyl rubber plate 100.
The A sheets 111 are stacked, a hole is made in the lead wire extraction part, a copper foil 113 with In-based solder is placed in the opening -L, and four solar cell elements 101 are placed in the opening -L, and each solar cell element is Lay out the polyimide tape 1 so that they do not touch each other.
I kept it at 03. Thereafter, a series wiring pattern 105 and a current collecting electrode pattern 104 were formed by applying silver paste with a dispenser. Furthermore, creamy silver-containing solder was applied onto the wiring pattern and the current collecting electrode pattern using a dispenser, and heat-treated. Finally, EV
Layer the A sheet and the polyhynylidene fluoride film sheet (112), and place it in a vacuum laminator to form 1.
A lead wire 115 was connected to the output terminal 113 by soldering, and the lead-out portion was sealed with silicone resin 116 to obtain an amorphous silicon solar cell module.

In the above solar cell module manufacturing method, the manufacturing process can be simplified and the amount of wiring material can be reduced by adopting a configuration in which the current collecting electrode and the connecting wiring are simultaneously formed on one side. The unevenness of the module surface is also reduced.
No more bubbles that sometimes appear in laminate.

AMl, 5 1 of a solar cell module in which four amorphous silicon solar cell elements with a two-pin configuration are integrated in series
The open circuit voltage (Voc) during light irradiation of 0Q, fi rewatt/cI112 is 3. It was l por 1.

Note that the Pin configuration conductor layer 105 is Pin/Pin.

A multilayer structure of Pin/Pin/Pin may be used, and materials such as amorphous silicon carbide or amorphous silicon germanium may be used for the semiconductor layer.

In the above embodiments, the case where amorphous silicon is used for the semiconductor layer has been explained, but the invention is not limited to this, but also when a compound semiconductor such as polycrystalline silicon or copper indium selenite is used for the semiconductor layer. , it can be applied to the solar cell having the structure of the present invention.

[Effects of the Invention] 6. According to the present invention, problems of solar cell modules formed on conventional conductive substrates are solved by forming a current collecting electrode and connection wiring for integration on one side at the same time. This solves the problem and simplifies the manufacturing process. Further, by employing the configuration of the solar cell module of the present invention, it becomes easy to automate the manufacturing process of integrated large-area solar cells, and it becomes possible to significantly reduce the manufacturing cost.

[Brief explanation of drawings]

Figures 1 (a), (b), and (c) are schematic configuration diagrams of a solar cell module in which four solar cells are integrated according to the present invention; Figures 2 (a) and (b) are Figure 1; 3 is a schematic diagram of a solar cell module used in a solar battery module according to the present invention, and FIG. 4 is a diagram of a conventional solar battery module. FIGS. 5(a) and 5(b) are schematic cross-sectional views of conventional solar cell modules. 105.400,500... Conductive substrate, 108.4
01,502...Metal electrode layer, 109.402,50
3...Semiconductor layer, 110.403, 504...Transparent electrode layer, 104.404...Collecting electrode, 105.405...Connection wiring, 103.501...Insulating material, 101... - Solar cell element, 100... Insulating base, 111... Filler, 112... Surface protective layer, 113... Output terminal, 115... Lead wire, 116... Sealink material. Unexamined Japanese Patent Publication No. 3 239377 (7)

Claims (3)

[Claims] (1) In a solar cell module manufactured by connecting a plurality of solar cell elements in which a metal electrode layer, a semiconductor layer, and a transparent electrode layer are sequentially formed on a conductive substrate, the plurality of solar cell elements are connected. The end faces of the solar cell elements are placed closely adjacent to each other on an insulating substrate, and the end faces of the solar cell elements are coated with an insulating resin at the portion through which wiring for electrically connecting the solar cell elements passes, and the transparent electrodes are coated with a conductive paste. A solar cell module characterized in that a current collecting electrode and connection wiring between the adjacent solar cell elements are formed on a light incident side. (2) The solar cell module according to claim 1, wherein the conductive paste is made of a conductive resin, a cream solder, or a conductive resin and a cream solder. (3) The solar cell module according to claim 1, wherein a part of the current collecting electrode and the wiring formed of the conductive paste are reinforced with a good conductor.