JP3176340B2 - Method of manufacturing solar cell module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a solar cell module. More specifically, the present invention relates to a method for manufacturing a solar cell module, which does not require removing a member laminated on a terminal portion of the solar cell after laminating the solar cell.

[0002]

2. Description of the Related Art A solar cell is an essentially clean energy source that does not emit exhaust gas, noise, or radioactivity. If a solar cell can charge a secondary battery and use energy,
It can be a stable energy source that can be used even at night.

For this reason, a combination of a solar cell and a secondary battery has been used since the beginning of the solar cell 30 years ago. FIG. 10 shows a typical example of the related art. In the figure,
(A) shows a solar battery charger, and (b) connects a load such as a wireless device.

A solar cell module 1 in which a plurality of solar cell elements are connected in series to extract a predetermined output voltage
001 is connected to the secondary battery 1003 through the overcharge prevention voltage control circuit 1005, and charges the battery 1003 or supplies power to the load 1004. When the voltage of the secondary battery 1003 reaches a predetermined voltage, the overcharge prevention circuit 1005 sets the output of the solar battery to 0N / 0FF, short-circuits the output of the solar battery, and charges the secondary battery. To stop. This prevents overcharge of the secondary battery and extends the life of the secondary battery. The secondary battery includes a battery that is built in the device from the beginning, and a battery that is detached and set in a device serving as a load for use.

Conventionally, a solar cell module having the above function is manufactured by laminating a solar cell in order to protect the solar cell from the surrounding environment and external force. At that time, after the terminal portion for taking out the output from the solar cell is laminated with the solar cell, the laminate member on the terminal portion is removed, and the terminal portion is exposed, and then the terminal portion is connected to the secondary battery or the like. Conventional solar cell modules have been manufactured by a method of electrically connecting to a load.

However, in the above method, a wasteful step of removing the laminate member on the terminal portion is required, and the terminal portion is also damaged by the step. Therefore, efficiency in manufacturing is improved, and the yield is improved. There was a problem that it was difficult to make it.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and can easily and accurately form a terminal portion. It is an object of the present invention to provide a method for manufacturing a solar cell module that does not cause damage to a part.

[0008]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a method of manufacturing a solar cell module having a terminal portion for extracting output from a laminated solar cell.
There is provided a method for manufacturing a solar cell module, comprising a step of laminating the solar cell after arranging a plug corresponding to the terminal portion.

[0009]

The operation of the present invention will be described below.

According to the step of laminating the solar cell after arranging the plug corresponding to the terminal for extracting the output from the solar cell, the terminal for extracting the output from the solar cell is placed on the terminal. Other portions of the solar cell can be covered with the laminate member without covering the laminate member. Therefore, in the laminated solar cell, the terminal portion is protected from the laminating member by the plug, and the terminal portion can be prevented from being contaminated by the laminating member. Can be

In addition, the step of removing the plug from the solar cell module formed in the step of laminating the solar cell and exposing the terminal section makes it possible to easily and accurately expose the terminal section. It is possible to avoid an increase in the number of steps accompanying the removal of the laminate member and damage to the terminal portions, which have occurred in the method. Then
By performing the step of electrically connecting the exposed terminal portion and the circuit for boosting the output voltage of the solar cell, the exposed terminal portion and the output of the solar cell can be easily and accurately connected to the exposed terminal portion. The connection of the circuit for boosting the voltage can be obtained more stably than before. As a result, a connection that is resistant to vibration, impact, and the like has become possible.

As the plug used in the above step, a rubber member having high flexibility is preferably used because of its excellent durability against lamination and easy removal after lamination. Further, in the above process, the place where the plug is arranged corresponding to the terminal portion is desirably on a lead wire constituting the solar cell. As the solar cell, a solar cell substrate and a photovoltaic provided on the solar cell substrate are provided. Those having a conversion layer are preferred.

The laminating process is characterized in that the laminating process is performed while depressurizing and degassing, and that a hot-melt type adhesive and a film are used. In addition, since the plug is arranged corresponding to the terminal portion, the lamination process is performed without providing a hot-melt type adhesive and a film in a portion corresponding to the plug. At this time, a copolymer of ethylene and vinyl acetate is preferable as the hot melt type adhesive, and a fluororesin film is preferable as the film. Further, it is a desirable form that the laminating process is performed by providing a crane glass between the film and the solar cell.

The solar cell according to the present invention includes a cell using crystalline silicon, polycrystalline silicon, amorphous silicon, or a compound semiconductor for the photoelectric conversion semiconductor layer. Among them, a tandem solar cell in which two or more photoelectric conversion semiconductor layers made of amorphous silicon are stacked on a thin and flexible conductive substrate is preferable.

The above solar cell suitable for the present invention is usually manufactured through the following steps.

An amorphous silicon layer having at least two or more PIN junctions is formed on a conductive substrate such as a stainless steel sheet having a clean and smooth surface by plasma CVD using silane gas or the like. Further, a transparent conductive film made of tin oxide, indium oxide, or the like is formed thereon by vapor deposition or spraying. And then,
The current collecting metal electrode is formed by screen-printing a conductive ink or depositing a metal. Finally, this is sealed with a light-transmitting weather-resistant resin such as an ethylene-vinyl acetate copolymer to obtain a solar cell. Since this type of solar cell can be continuously produced by the so-called roll-to-roll method, it has extremely high productivity,
It is expected that costs will be significantly reduced in the future. In addition, there is a feature that the area can be easily increased and additional processing such as cutting can be performed.

The electric power generated by the solar cell is supplied to the secondary battery by increasing the voltage in a booster circuit. A DC / DC converter of a chopper type or a charge pump type can be used for boosting.

The secondary battery includes a nickel cadmium battery, a lead battery, a nickel hydride battery, a lithium secondary battery and the like.
In particular, a lithium secondary battery has excellent performance such as high energy density, low self-discharge, and high operating voltage, and is suitable for the present invention. Examples of the lithium secondary battery include a carbon lithium secondary battery, a vanadium-lithium secondary battery, a polyaniline-lithium secondary battery, and a lithium ion secondary battery.

In the solar cell module according to the present invention, the solar cell and the booster circuit may be formed integrally. With this configuration, the battery can be charged simply by being directly connected to a secondary battery of a small electronic device, being resistant to vibration, shock, and the like. In addition, since the secondary battery functions as a constant voltage power supply, overcharge of the secondary battery can be prevented.

The solar cell used in the solar cell module of the present invention includes, as described above, single-crystal silicon, polycrystalline silicon, amorphous silicon solar cell, etc.
A compound type, a hybrid type or the like can also be used. However, since the IC booster circuit is used,
It is desirable that the output current from the solar cell module be 1 A or less. The output voltage is 0.5 V, more preferably 1 V, so that the booster circuit formed as an IC can be driven.
It is desirable to have the above. More preferably, a lightweight and flexible amorphous silicon solar cell is desirable, and among them, the optimal operating voltage is 1 V or more, and pi
An amorphous silicon solar cell in which two or more n layers are stacked is optimal. As a flexible film forming substrate, a heat-resistant resin film such as polyimide may be used as an organic material in addition to a stainless steel plate and an aluminum plate.

The solar cell must have a terminal for taking out the output. Although the solar cell according to the present invention is sealed in a resin, as a result of arranging a plug on the terminal portion and laminating, it is possible to expose the terminal portion only by removing the plug after the lamination process. It has the characteristic that it can be done. Thus, it is possible to avoid an increase in the number of steps involved in removing the laminate member and damage to the terminal portions, which occur in the conventional manufacturing method. In the present invention, the booster circuit may be integrally attached to the lead wire take-out portion which is the terminal portion, or the circuit may be attached to an appropriate place on the entire surface of the module by extending the lead wire.

The surface of the solar cell is covered with a glass plate or a weather-resistant fluororesin film. Adhesive is attached to the glass surface, but fluororesin film has low wettability,
Adhesive is hard to adhere. For this reason, the adhesion effect is enhanced by rubbing with sandpaper or processing such as plasma etching. Of course, it may be mechanically stopped with a screw or the like.

One or more cells are accommodated in the solar cell module. If multiple cells are accommodated, they are connected in series with each other,
They are connected in parallel. The method of series connection or parallel connection may be a commonly used method.

A step-up circuit according to the present invention comprises a step-up DC / DC converter integrated into an IC, a step-up coil, a backflow prevention diode, a resistance element for determining a step-up ratio,
It is composed of external components such as a capacitor for stabilizing the output voltage.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

(Example 1) A method for manufacturing a solar cell module in which a booster circuit is housed in a terminal box of a lead wire take-out part of a laminated module composed of a single cell of a flexible amorphous silicon solar cell will be described in detail.

A stainless steel plate having a thickness of 0.125 mm was prepared as a substrate for an amorphous silicon solar cell. On this substrate, a back reflection layer made of zinc oxide and aluminum was formed to a thickness of about 500 nm by a sputtering method. Next, on the back reflection layer, n, i, and p layers of amorphous silicon were sequentially formed three times by a plasma CVD method to form a triple cell in which three nip photoelectric conversion layers were stacked. The i-layers of the bottom cell and the middle cell contain germanium, and the band gap was narrowed so that long-wavelength light could be efficiently absorbed.

Indium oxide was vacuum-deposited as a transparent conductive film to a thickness of 70 nm on the surface of the photoelectric conversion layer made of amorphous silicon. The cell substrate thus formed is 10 × 20c
m.

Further, a silver paste was printed as a current collecting grid on the transparent conductive film by a screen printing method.
Cure at 0 ° C. for 20 minutes. In FIG. 1, reference numeral 100 denotes an amorphous silicon solar cell formed on stainless steel, and reference numeral 101 denotes a current collecting grid of silver paste. The width of the current collecting grid 101 was 100 μm, and the total thickness of the silver paste and the solder layer was 60 μm by dipping in a solder bath. The current collecting grid 101 is connected to the grid 102 at the edge, and the grid 102 is further connected to a lead wire 103 of 2.54 mm in width and 50 μm in thickness, which is tin-plated with copper, using silver paste. The lead wire 103 is used as a plus terminal lead wire as described later.

When the solar cell manufactured by the above procedure was measured under a standard light source AM of 1.5 and a light source of 100 mW / cm ² , an optimum operating voltage of 1.8 V and an optimum operating current of 1 A were obtained.

In the solar cell of this configuration, the stainless steel substrate side becomes a negative terminal, and the surface side of the cell, that is, the light receiving surface side becomes a positive terminal. The negative terminal lead wire 104 is connected to a stainless steel substrate by spot welding with a copper piece having a width of 2.54 mm and a thickness of 0.5 mm.
3 and into the terminal box 105 in the laminate.

FIG. 2 is a schematic sectional view showing a layer structure when the solar cell shown in FIG. 1 is laminated. FIG.
As shown in the figure, a hot melt type adhesive EVA (copolymer of ethylene and vinyl acetate) 202, a crane glass 205, and a nylon sheet 206 are sequentially laminated on the substrate side of the solar cell 200, A crane glass 205 and a hot melt type adhesive EVA (a copolymer of ethylene and vinyl acetate) 2
02, a configuration in which the weather-resistant fluororesin films 201 are sequentially laminated. Such a laminate was laminated in a vacuum at 150 ° C. for 1 hour while degassing under pressure. In order to take out the terminal later, lamination was performed with the rubber stopper 207 attached to the lead wires 203 and 204 as the terminal portions before lamination. That is, since the plug was arranged corresponding to the terminal portion for extracting the output from the solar cell, and then the solar cell was laminated, the laminated member was coated on the terminal portion for extracting the output from the solar cell. Without this, other parts of the solar cell can be covered with the laminate member. Therefore, in the laminated solar cell, the terminal portion was protected from the laminating member by the stopper, and the terminal portion could be prevented from being contaminated by the laminating member.

Next, the plug was removed from the solar cell module formed by laminating the solar cell to expose the terminal portion. This makes it possible to easily and accurately expose the terminal portion, thereby making it possible to avoid an increase in the number of steps involved in removing the laminate member and damage to the terminal portion, which occur in the conventional manufacturing method.

Thereafter, the exposed terminal portion was electrically connected to a circuit for increasing the output voltage of the solar cell. Since the connection with the exposed terminal portion can be easily and accurately made, the connection between the exposed terminal portion and the circuit for boosting the output voltage of the solar cell can be more stably obtained than before. As a result, a connection resistant to vibration, impact, and the like was obtained.

As a step-up DC / DC converter integrated into an IC functioning as a circuit for stepping up the output voltage of the solar cell, an LT1073 was used. Package size is length 1
cm, width 7 mm, thickness 4 mm or less. The circuit configuration is as shown in FIG. In FIG. 3, reference numeral 301 denotes LT10
73 and 302 are coils, 303 is a backflow prevention diode,
304 and 305 are resistors, 306 is a capacitor, 30
7 and 308 are DC input terminals, and 309 and 310 are DC input terminals.
Output terminal. In this configuration, since the output voltage is a constant voltage power supply of 4 V, a lithium secondary battery of 3.6 V can be charged, and overcharging of 4 V or more cannot be performed. In addition, since the backflow prevention diode 303 is provided, backflow from the secondary battery is prevented.

In this embodiment, as shown in FIG. 4, the terminal box was integrally attached to the side end of the solar cell module so as to cover the front and back surfaces. Reference numeral 402 denotes a laminate module, reference numeral 401 denotes a solar cell, and a positive lead wire 403 extending from the surface of the cell and a negative lead wire 404 spot-welded from the stainless steel substrate extend into the terminal box. Lead wires 407 and 418 soldered 406 extend from 403 and 404 and are connected to a printed circuit board in the terminal box. The terminal box is composed of an upper lid 408 and a lower lid 409. The terminal box is in contact with the surface of the module via a silicone resin 410 and is pressed to prevent moisture from entering. The portion of the fluororesin surface to which the silicone resin was applied was rubbed with sandpaper in advance in order to enhance the anchoring effect of bonding, so that the surface was roughened. The upper and lower lids are adhered to each other via an adhesive at a portion 413, and are further fixed through screws through the upper and lower lids (not shown). The upper lid 408 has a space 412 for accommodating the booster circuit and a hole 411 for passing the output cable 417. In the space 412, external components such as a printed circuit board 414 of a booster circuit, a booster DC / DC converter 415 formed into an IC, and a coil 416 are accommodated. The space 412 covering the circuit was filled with epoxy resin.

Using the above solar cell module, a mobile phone was charged. Rated output 30mW, 3V at transmission, 1
It requires 0 mA of power and is always in a standby state. At this time, it consumes 3 V and 2 mA of power. Since the capacity of the lithium secondary battery is 500 mAh, the battery runs out on the eleventh day only in the standby state. The output of the solar cell is 1.8 under AM 1.5 and 100 mW / cm ^2.
V, 1A, but under fluorescent lamps, 1V, 10mA.
When this was passed through a booster circuit, the charging current became 3.6 V and 2.2 mA, and the current consumption in the standby state could be sufficiently covered by the solar cell alone.

(Embodiment 2) In this embodiment, an example in which four amorphous silicon solar cells formed on a flexible substrate are connected in parallel and terminals are taken out from the back of the module will be described in detail below. explain.

As the solar cell, a triple cell was manufactured in the same manner as in Example 1. Four 10 × 5 cm cells were cut out from the film formation substrate. These cells were connected in parallel. In FIG. 5, reference numeral 501 denotes this module, 502 denotes each solar cell,
503 is a plus side lead wire connected in parallel,
Reference numeral 504 denotes a negative lead wire. The lead wire can be taken out from the back of the module through holes 505 and 506 formed on the lower side of the module.

When the performance of the solar cell manufactured as described above was measured, an optimum operating voltage of 1.8 V and an optimum operating current of 1 A were obtained under a standard light source of AM 1.5 and 100 mW / cm ² .

As a circuit for boosting the output voltage of the solar cell, a DC / DC converter I manufactured by Maxim shown in FIG.
C, a boost converter was manufactured using AX630. In the present embodiment, the boost ratio is set to 6 times, and the output voltage is set to 10.
8V. In FIG. 6, 601 is MAX 630, 6
02 is a coil, 603 is a backflow prevention diode, 604 and 605 are resistors, and 606 is a capacitor.

The size of the MAX 630 is 9 mm in length, 6 mm in width, and 3.5 mm in thickness. 3x3 for all parts
cm on a printed circuit board.

Next, a booster circuit was attached as shown in FIG.
FIG. 7 is a schematic plan view showing the back surface of the module,
It is a drawing in which a part of the opening is opened so that the printed circuit board of the booster circuit can be seen. A printed circuit board 702 of the booster circuit was arranged adjacent to the terminal extraction holes 706 and 705. 703 is MAX630, 704 is an external component, and 707 is an output cable. Nylon film 701 on the back of the module
The top was coated with a silicone resin, a printed circuit board was mounted thereon, the lead-out portion and the printed circuit board were all filled with the silicone resin, and a cosmetic plastic cover (not shown) was covered.

Using the solar cell module manufactured as described above, a NiCd secondary battery (9.6 V, 1600 mAh) of a video camera with a built-in camera was charged. The photovoltaic cells were placed so that they faced the sunny side of the window, facing the south side. In spite of frequent partial projections such as window frames and curtains, a current of 2 Ah could be taken out of the solar cell in one day on a clear day. As the output from the booster circuit, charging power of 10.8 V and 148 mAh was output. Therefore, it was proved that if there was about 11 sunny days, the battery was fully charged from an empty state.

(Embodiment 3) In this embodiment, a module was formed by connecting three polycrystalline silicon wafers in series, and a booster circuit was mounted on the back surface of the module.

As shown in FIG. 8, a polycrystalline silicon solar cell 3 with a current collecting grid 801 and a bus bar 803
Prepared. The size of one cell is 2 cm × 5 cm. These cells were connected in series. FIG. 9 shows the configuration of the laminate. The cell is sealed in EVA (copolymer of ethylene and vinyl acetate) 806 and the surface is 3 mm thick
The bottom surface is protected by a 1 mm thick anodized aluminum plate. When the electrical characteristics of the module manufactured in this manner were measured, AM
Under a standard light source of 1.5 and 100 mW / cm ² , an optimum operating current of 300 mA and an optimum operating voltage of 1.26 V were obtained.

As in Example 1, LT1073 manufactured by Linear Technology was used. The step-up ratio was tripled, and the charging voltage was 3.78V.

As shown in FIG. 9, an aluminum plate and E
VA (copolymer of ethylene and vinyl acetate) has a hole for taking out a lead wire using a rubber stopper as in Example 1. A lead wire 907 with an insulating film extends from the plus terminal 904 and is connected to the printed circuit board 908 of the booster circuit. Although the lead wire from the minus terminal is not shown, it was wired similarly. Reference numeral 909 denotes a booster circuit element, reference numeral 910 denotes an output cable, and reference numeral 912 denotes a terminal box which is adhered to an aluminum plate 905 via a silicon resin.

The lithium secondary battery of the still picture photographing apparatus was charged by using the module of this embodiment. The capacity of the lithium battery is 3.6 V, 500 mAh. When the solar cell was attached to the window glass, during a clear day, during 4 hours, 1
A charging current of 20 mAh was obtained. From these results, it was proved that a full charge could be achieved if there were five similar sunny days.

[0050]

As described above, according to the present invention,
Provided is a method for manufacturing a solar cell module, in which a terminal portion of a laminated solar cell is protected from a laminate member by a plug, so that the terminal portion can be prevented from being contaminated by the laminate member. it can. Further, the terminal portion can be easily and accurately exposed by removing the plug from the solar cell module formed in the step of laminating the solar cell to expose the terminal portion. Further, by performing the step of electrically connecting the exposed terminal portion and the circuit for boosting the output voltage of the solar cell, the exposed terminal portion can be easily and accurately connected to the exposed terminal portion, so that the exposed terminal portion and the solar cell Is more stably obtained than the conventional circuit. Therefore, according to the present invention, a method for manufacturing a solar cell module having a strong connection against vibration, impact, and the like can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic plan view illustrating a solar cell module having a charging function according to a first embodiment.

FIG. 2 is a schematic cross-sectional view illustrating a solar cell module having a charging function according to a first embodiment.

FIG. 3 is a schematic diagram illustrating an example of a booster circuit used in the present invention.

FIG. 4 is an enlarged cross-sectional view of the terminal box according to the first embodiment.

FIG. 5 is a schematic top view showing a solar cell module having a charging function according to a second embodiment.

FIG. 6 is a schematic diagram showing another example of a booster circuit used in the present invention.

FIG. 7 is a schematic bottom view showing a solar cell module having a charging function according to a second embodiment.

FIG. 8 is a schematic plan view illustrating a solar cell module having a charging function according to a third embodiment.

FIG. 9 is a schematic cross-sectional view illustrating a solar cell module having a charging function according to a third embodiment.

FIG. 10 is a configuration example of a conventional charging device and a device using a solar cell.

[Explanation of symbols]

 Reference Signs List 100 amorphous silicon solar cell, 101 collector electrode, 102 grid, 103 positive terminal lead, 104 negative terminal lead, 105 terminal box, 200 solar cell, 201 fluororesin film, 202 adhesive, 203 positive terminal lead, 204 Negative terminal lead wire, 205 crane glass, 206 nylon sheet, 207 rubber stopper, 301 LT1073, 302 coil, 303 backflow prevention diode, 304, 305 resistor 306 capacitor, 307, 308 DC input terminal, 309, 310 DC output terminal, 401 Solar cell, 402 laminate module, 403 plus terminal lead, 404 minus terminal lead, 406 soldered location, 407 lead, 408 top lid, 409 bottom lid, 4 10 Silicon resin, 411 hole, 412 space, 413 connection part, 414 printed circuit board, 415 boost DC / DC converter, 416 coil, 417 output cable, 418 lead wire, 501 module, 502 solar cell, 503 plus terminal lead wire, 504 Negative terminal lead wire, 505, 506 hole, 601 MAX630, 602 coil, 603 Backflow prevention diode, 604, 605 Resistance 606 Capacitor, 701 nylon film, 702 Printed circuit board, 703 MAX630, 704 External parts, 705, 706 Terminal extraction Hole, 707 output cable, 801 current collector grid, 803 bus bar, 902 protective glass, 905 aluminum plate, 906 EVA, 907 lead wire with insulation coating, 908 plug Cement substrate, 909 the booster circuit elements, 910 output cable, 912 terminal box, 1001 solar cells, 1003 battery, 1004 loads, 1005 overcharge prevention voltage control circuit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 31/04-31/078

Claims (11)

(57) [Claims] 1. A method for manufacturing a solar cell module having a terminal portion for taking out an output from a laminated solar cell, wherein a plug is arranged corresponding to the terminal portion, and then the solar cell is laminated. A method for manufacturing a solar cell module, comprising the steps of: 2. A step of removing the plug from the solar cell module formed by the step of laminating the solar cell to expose the terminal, and increasing the output voltage of the exposed terminal and the solar cell. And a step of electrically connecting a circuit to be manufactured. 3. The method according to claim 1, wherein the plug is a rubber member. 4. The method for manufacturing a solar cell module according to claim 1, wherein the place where the plug is arranged corresponding to the terminal portion is on a lead wire constituting the solar cell. 5. The method according to claim 1, wherein the solar cell has a solar cell substrate and a photoelectric conversion layer provided on the solar cell substrate. 6. The method for manufacturing a solar cell module according to claim 1, wherein the laminating process is performed while removing pressure. 7. The method according to claim 1, wherein the lamination is performed using a hot-melt adhesive and a film. 8. The solar cell module according to claim 7, wherein the lamination is performed without providing the hot-melt type adhesive and the film on a portion corresponding to the plug. Method. 9. The method according to claim 7, wherein the hot-melt adhesive is a copolymer of ethylene and vinyl acetate. 10. The method according to claim 7, wherein the film is a fluororesin film. 11. The method according to claim 7, wherein the laminating process is performed by providing a crane glass between the film and the solar cell.