JPS5817687A - Sealing method for solar cell - Google Patents

Abstract

PURPOSE:To seal the solar cell with a material having excellent transparency and working property by using a module blank material employing a transparent thermoplastic resin sheet. CONSTITUTION:The device consists of a die 5 with a vacuum system piping 3 and a heating means 4, a cylinder 7 for pressure, which operates the inside of the die under an airtight state, and an elastic body board 2 mounted to the nose of the cylinder, the solar cell module blank 1 formed in order of a surface material/the transparent thermoplastic resin sheet/the solar cell/a thermoplastic resin sheet/a back material is brought to a decompression state, a gas such as air in the module blank is removed, and the module blank is pressed and pressure-welded by the elastic body at the temperature of the melting point or higher of the thermoplastic resin and unified. Accordingly, the solar cell module, which is excellent in every aspect of characteristics with low cost is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for encapsulating a solar cell, and more particularly to a method for manufacturing a solar cell module using thermoplastic resin sorting.

Methods for encapsulating solar cells include casting using silicone resin, which has good transparency and weather resistance and has a proven track record as a semiconductor encapsulating resin, and transparent thermoplastic resin sheets using rolls and an autoclave. Methods such as laminating are known. However, methods such as casting using silicone resin have disadvantages in that the silicone resin is expensive and the casting operation requires time and man-hours. Furthermore, the method of laminating transparent thermoplastic resin sheets using a one-call/autoclave method has the drawback that the solar cells may be damaged due to residual bubbles and secondary foaming caused by being left at high temperatures.

Therefore, the present invention eliminates the drawbacks of the conventional sealing method as described above, and also has excellent transparency and workability that enables the use of a thermoplastic resin sheet that is cheaper than silicone resin. Another object of the present invention is to provide a low-cost solar cell sealing method.

To seal the solar cells, a thermoplastic resin sheet is inserted between the front material and the solar cell and between the solar cell and the back material, and the module material configured in this way is placed in a reduced pressure environment. It was found that a solar cell module with excellent various properties and low cost can be manufactured by integrating the materials by pressure-bonding them with an elastic body at a temperature higher than the melting point of the thermoplastic resin.

According to the present invention, a solar cell module material configured in the order of surface material/transparent thermoplastic resin sheet/solar cell/thermoplastic resin sheet/back material is subjected to reduced pressure to remove the After removing gases such as air,
A method for manufacturing a solar cell module is provided, which comprises integrating solar cell modules by pressurizing and crimping them with an elastic body at a temperature equal to or higher than the melting point of a thermoplastic resin.

In the method of the present invention, the solar cell module material (hereinafter also simply referred to as module material) refers to the surface material/transparent thermoplastic resin sheet/solar cell/thermoplastic resin sheet before being integrated into the solar cell module. / Refers to a structure in which the backing materials are stacked one on top of the other in this order.

Various materials that are transparent and have high mechanical strength can be used as the surface material of the solar cell module material as described above. For example, such materials include glass plates,
Various types of glass fiber reinforced plastics (FRP), such as glass fiber reinforced polyester, polycarbonate, polysulfone, polyacetal, etc., are listed1, as well as transparent epoxy, unsaturated polyester, and acrylic resins that are not reinforced with glass fiber. , a resin plate made of Teflon or the like can also be used. The thickness of the surface material can be selected arbitrarily.

It is important that the thermoplastic resin sheet inserted between the surface material and the solar cell be transparent and have good thermal adhesion to the surface material and the solar cell. Such transparent thermoplastic resin notes include polyvinyl butyral (PBV), ethylene-vinyl acetate copolymer (EvA), ethylene-methacrylic acid copolymer ionomer (KMA 7 ionomer), polymethyl methacrylate (PMMA), Other sheets such as polymethacrylate resin. The thickness of the sheet can be selected within a wide range, but is preferably 10 μm to 2 μm.

There are many solar cells that can be modularized using the method of the present invention. For example, single crystal S1 cell,
Si+J Bon crystal cell, Si substrate polycrystalline S1 cell, SU
S substrate Substrate 7 Full-circle S1 Cellular substrate An example is a substrate formed by wiring amorphous Si cells.

It is important that the thermoplastic resin sheet inserted between the solar cell and the backing material exhibits good thermal adhesion to both. Such a thermoplastic resin sheet may be the same as the transparent thermoplastic resin described above. Other resin sheets with good heat fusion properties can also be used. The thickness of the sheet may be arbitrary, but is preferably 10 pm to 2 mm.

Many materials can be used as the backing material. Such materials include thermoplastic films with a thickness of 10μ to III, such as Tef, Ron, PBT, and polyester;
Thermoplastic films containing inorganic fillers such as titanium white, thermoplastic films laminated with metal foils such as aluminum, 10-100 μm metal foil films of aluminum, copper, etc., metal plates such as glass, aluminum, iron, concrete, asbestos. Examples include inorganic boards such as , wood boards, etc.

According to the present invention, the solar cell module material constructed in the above-mentioned order is placed under reduced pressure to remove air contained therein. The reduced pressure condition is preferably 10■Hf
The duration is 2 to 10 minutes and can vary depending on the module material.

After the air in the module material is removed, the module material is then heated to a temperature higher than the melting point of the thermoplastic resin and is crimped and integrated with an elastic body under pressure to form a solar cell module. The pressurizing conditions are preferably 1 to 5 Kg/d (0.5 to 20 minutes at gauge pressure, but can be changed depending on the module material. As an elastic body, the pressure should not mechanically damage the module material. Elastic materials such as

The method of manufacturing a solar cell module according to the present invention as described above can be carried out using various devices, and these devices will be explained in the Examples section. Furthermore, the apparatus described in the patent application of the same date (title of invention: device for sealing solar cells) by the applicant is particularly preferred for carrying out the method of the invention.

The method of the invention provides many advantages, including:

1) Cheap PVB, FiV instead of silicone resin
By using a thermoplastic resin sheet such as A, the cost per thousand joules (material cost + processing cost) is extremely low.

2) Compared to the conventional roll-autoclave combination method,
The time for crimping and integrating module materials is greatly reduced.

3) The combination of the surface material and back material structure is a flat plate-flat structure (e.g. glass/glass, yMp/yRp, glass/FRP
Solar cell modules can be manufactured using the same equipment for various module materials such as transparent film-flat plate (glass, FRP, etc.) structures.

4) Connection can be made by mechanical crimping without soldering the electrode lead wires at the same time as crimping the sheet or film, and processes such as soldering can be omitted. This method also provides a new way to connect the leads.

Hereinafter, the method of the present invention will be illustrated in detail using Examples.

Example 1 This example uses various types of glass/PV as shown in FIG.
B sheet/solar cell/PV B sheet/white Teflon film layered module material is used as the second to second layer.
A method for manufacturing a solar cell module using an apparatus as shown in FIG. 4 will be illustrated.

In FIG. 1, 1 is a solar cell (for example, single crystal S1
Cell, 5ilJ Bo/Crystalline cell, Si substrate polycrystalline cell, S
2 is a glass plate, 3 is a foil lead wire, and 4 is a transparent resin sheet (thickness 0.7611III including plasticizer) PvB. 5 is a white Teflon film (a Teflon film containing an ultraviolet absorber, "Tetra" (Dow Chemical Company)). (manufactured by) film).

The apparatus shown in FIG. 2 consists of a mold 5 having a vacuum system piping 3 and a heating means 4, a pressurizing cylinder 7 that operates in an airtight manner inside the mold, and an elastic plate 2 provided at the tip of the cylinder. This is a device configured to be able to pressure bond solar cell module materials. 6 is Patsukin.

FIG. 3 shows a system in which the pressure can be adjusted by a vacuum system 3 and a heating means 4.
It consists of upper and lower molds 5 that can be heated by heating, and a pressure-bonding film 8 having elasticity to pressure-bond the solar cell module material 1 between them. This is a device configured as follows.

FIG. 4 shows a vacuum heating furnace 10 equipped with a vacuum system 3 and heating means 4, which includes a pressure roll pair 9 having an elastic body 2 and a conveying device for the solar cell module material 1. 11 is a lid.

Using these devices, the solar cell module material containing the above structure was heated to about 80°C and heated to 10 trmH2.
After holding the following for 2 to 10 minutes, 1 to 5
An integrated solar cell module was fabricated by pressure bonding at Kg/cnI gauge pressure for 0.5 to 20 minutes.

The solar cell module manufactured in this manner had good appearance and characteristics, with no damage to the battery cells or residual air bubbles. In addition, even after conducting a heat cycle test of 80℃ to -40℃ for 10 cycles, a high temperature storage test for 2000 hours at Button℃, and a weatherometer test for 1000 hours,
No changes in appearance such as secondary foaming or deterioration of properties were observed.

Comparative Example 1 This shows the production of a solar cell module using a conventional roll-autoclave combination method. Figure 5 shows an overview of the equipment used. In this method, a module material 1 is introduced into a heating furnace 4 by a front pressure bonding roll 2, heated by a heater 5, and then a solar cell module is taken out by a back pressure roll 3, which is connected to a pressure piping 7 and a heating/cooling arrangement 8. It is charged into the equipped autoclave 6 to form a product module.

Using this apparatus, various solar cell module materials Q lath/PVB/solar cell/PVB/white Tetler film having the configuration shown in FIG. The cells used were a single crystal S1 cell, a Si ribbon crystal cell, an 8U8 substrate amorphous S1 cell, and a glass substrate amorphous S1 cell) that were crimped and integrated. The main manufacturing conditions are (1) roll conditions, front roll pressure 2 Kr/ctI, heating furnace temperature 250°C, heating furnace heating time 2 minutes, rear roll pressure 2Kt/! , (2) Autoclave conditions, temperature 120°C
, pressure 5 Kg/cM, time addition.

The following points were observed in the solar cell module manufactured by this method.

b) There was a risk that some of the solar cells might break.

Mouth) In the module material containing square solar cells, air bubbles remained at the corners of the solar cells.

ノ・) Both solar cell modules are subject to room temperature storage tests and (
(Note) Generation and increase of multiple bubbles (secondary foaming) were observed in the high temperature storage test at ℃.

Example 2 Various solar cell module materials having the configurations shown in the table below were crimped and integrated under the same manufacturing conditions as in Example 1 using the apparatus shown in FIG. 3 to produce solar cell modules. In addition, when making a module with structures 1 and 2 in which both the front and back materials are made of hard materials such as glass or FRP, the solar cells are placed around the solar cells for the purpose of adjusting the thickness. A PVB sheet with approximately the same thickness as the cell was inserted.

Composition of module material 1) Nlll: Glass/PVB/Solar cell/PV
B/711/2 S2: FRP/PYB/Solar battery center/PV
B/'F RP3: Transparent tetra-film/P
V B /Solar cell/PVB/Iron plate 4: Glass/EVA2)/Solar cell/KVA/White tetra-film 3) 5: Glass/Ionomer/Solar cell/Ionomer/White tetra-film Note 1) Stainless steel substrate Amorphous S1 cell, glass substrate amorphous S1 cell, and ribbon crystal S1 cell are used.

2) Ethylene-vinyl acetate copolymer, XXXXXXX× ×
××××××××.

3) Ionomer, XXXXX XXXXXXX
XX.

In the solar cell modules manufactured as described above with various configurations, no damage to the battery cells, no residual bubbles, and no deterioration in characteristics were observed. Furthermore, no bubble generation or deterioration of properties was observed in a 2000 hour high temperature storage test at 80°C to -40°C heat cycle test.

Comparative Example 2 Using the apparatus shown in Fig. 2, but without applying a vacuum condition, a module material laminated with a structure of glass/PVB/solar cell (SUSi & amorphous S1 cell)/PVB/Tetler film was made into gold. Mold temperature ℃, pressure 3
A solar cell module was manufactured under the conditions of Kg/t:rl. There were some air bubbles left in this module, so
It was further treated in an autoclave at 150° C. and a pressure of 5 K9/Ca. In the solar cell module manufactured by this method, air bubbles remained at the corners of the module, and generation (secondary foaming) and increase of air bubbles were observed in the 80° C. high temperature test.

Example 3 Among the modules with various structures manufactured in Example 2,
For example, when the backing material was a Teflon film containing titanium white (Tetra Film), it was found that the adhesive strength between the film and PVB was weak.

For this purpose, process in a dryer at 150°C for 1 hour or 25°C.
It was found that the adhesive strength was greatly improved by blowing hot air at 0° C. for 5 minutes.

Example 4 In manufacturing a solar cell module having the configuration shown in FIG. 1, ethylene-vinyl acetate copolymer (Fj'VA) film, methacrylic (PMM) film
A) Film, ionomer (10) film, EV
The experiment was carried out under the same conditions as in Example 1, using a laminate film of A/IO and a laminate film of PS/O, using a modularization apparatus shown in FIG. 3. However, the temperature of the mold was set as follows.

EVA: 110℃, PS: 150℃,
PMMA: 150°C, temperature: 10°C, E
VA/O: 120℃, PS/O: 13
0°C Solar cell modules using these various thermoplastic resin sheets contained no air bubbles and no deterioration in characteristics was observed. In addition, (C) high temperature storage test, 8
No generation of bubbles or deterioration of cell properties was observed in heat cycle tests from 0°C to -40°C.

Example 5 A solar cell was placed on a glass/PVB sheet, and wiring lead wires were placed without any fixing work such as soldering. A PVB7-)/Tetler film was laminated thereon. The lead wire used was copper foil plated with soft metal such as silver or lead. The module materials having this stacked structure were crimped and integrated using the same method as in Example 1. As a result, a module was obtained in which the Sissel lead wire-PVB was in good contact without moving from the intended position. This solar cell module had no damage to the battery cells or residual air bubbles, and had good appearance and cell characteristics. In addition, we conducted a heat cycle test at 80°C to -40°C for 10 cycles, a high temperature storage test at 80°C for 2000 hours, and 1
Even after 1,000 hours of weatherometer testing, no changes in appearance such as secondary foaming or deterioration of properties were observed.

This method has the advantage that lead wires can be connected at the same time.

[Brief explanation of drawings]

FIG. 1 is a front view (A) showing the configuration of a typical solar cell module material that can be modularized by the method of the present invention.
and a side view (B). 2, 3, and 4 are schematic diagrams showing a solar cell module manufacturing apparatus that can be used to carry out the method of the present invention. FIG. 5 shows a solar cell module manufacturing apparatus according to the prior art. A schematic diagram of the device 0 1...Solar cell module material, 2...Elastic body plate,
3... Vacuum system, 4... Heating means, 5... Mold, 6
...Packskin, 7...Pressure cylinder, 8...
Pressure bonding film, 9...Pair of pressure bonding rolls, 10...Vacuum heating furnace, 10a...Lid, 11...Solar cell, 12.
... Glass plate, 13 ... Foil lead wire, 14 ... Transparent resin sheet, 15 ... White Teflon film, 1
01... Module material, 102... Front pressure roll, 103... Back pressure roll, 104... Heating furnace, 10
5... Heater, 106... Autoclave, 10
7...Pipe for pressurization, 108...Piping for heating and cooling. Patent applicant: Fuji Electric Manufacturing Co., Ltd. Fuji Electric Research Institute Co., Ltd.-42“

Claims (1)

[Scope of Claims] (1) A solar cell module material configured in the order of surface material/transparent thermoplastic resin sheet/solar cell/thermoplastic resin sheet/back material is subjected to reduced pressure to A method for manufacturing a solar cell module, which comprises removing a gas such as air and then integrating the thermoplastic resin by applying pressure and crimping with an elastic body at a temperature higher than the melting point of the thermoplastic resin. (2. The method for manufacturing a solar cell module according to claim 1, characterized in that the module material is subjected to a reduced pressure of 10 mHf or less for 2 to 10 minutes. (3) Claim 1. In the method for manufacturing a solar cell module according to item 1, the module material is divided into 1 to 5 to 9/c.
A manufacturing method characterized by integrating by subjecting to 111 gauge pressure for 0.5 to 20 minutes.