CN107231819A - The manufacture method of solar cell module and solar cell module - Google Patents

Abstract

The solar cell module is a solar cell module with a light-transmitting substrate on the light-receiving side and a back protection material on the back side. As the packaging material between the light-receiving side light-transmitting substrate and the solar cell element, EVA (ethylene- Vinyl acetate copolymer) and silicone are adjacent and laminated, and the solar cell element and the back protection material are sealed with EVA. The solar cell module of the present invention does not undergo significant changes in the solar cell module manufacturing process, can be easily produced using a vacuum laminator, and has great resistance to the PID phenomenon, suppressing the output of the solar cell module associated with the PID phenomenon Reduced power.

Description

Solar cell module and method for manufacturing solar cell module

technical field

The present invention relates to a solar cell module and a manufacturing method thereof.

Background technique

A crystalline solar cell module formed by connecting solar cell elements made of semiconductor substrates such as silicon has a light-transmitting substrate such as glass on the light-receiving surface side, and has a light-transmitting substrate such as glass or a PET film on the rearmost side EVA is widely used as an encapsulation material in between for the back protection material.

On the other hand, in recent years, a large number of photovoltaic power generation systems called mega solars have been constructed with large-scale power generation capacity. In such a photovoltaic power generation system having a large-scale power generation capacity, the voltage applied to each solar cell module may become a high voltage, and the output of the solar cell module may decrease depending on the outdoor conditions where it is installed. This output power reduction phenomenon is called PID (Potential Induced Degradation).

As one of the reasons, it has been reported that by applying a high voltage to the module alone, the Na ⁺ component in the glass passes through the encapsulation material and reaches the surface of the solar cell, and as a result, the surface of the solar cell recombines and the output Power reduction (Non-Patent Document 1).

As a measure for improving such a problem, there is an improvement of an anti-reflection film on a light-receiving surface of a solar battery cell (Patent Document 1).

However, the improvement of the anti-reflection coating on the light-receiving surface has problems such as slightly lowering the output power of the solar cell and requiring improvement in equipment in the process of forming the anti-reflection film of the solar cell.

In addition, as a countermeasure for the solar power generation system, there is a method of using an inverter attached to an insulating transformer to make the power generation element part of the solar cell module a negative potential. However, a large number of transformerless converters have been introduced for the purpose of increasing the efficiency of the converter and reducing the cost, and it is difficult to take measures to change the system.

As a countermeasure for improving such a problem, there is a change of packaging material. A large number of PID phenomena are generally confirmed when EVA is used (Non-Patent Document 1). Ionomers are mentioned as encapsulating materials having PID resistance, but ionomers have a problem of high cost, which increases the production cost of solar cell modules.

In addition, a solar cell module having a structure sealed with a laminate of an ionomer and EVA has also been proposed (Non-Patent Document 2). In this structure, the ionomer prevents the diffusion of Na ⁺ from the light-receiving glass, and can suppress the occurrence of PID. However, when the ionomer and EVA are stacked on a vacuum laminator and heated, vacuumed, and pressed, air bubbles tend to remain at the interface, making it difficult to obtain a good molded body. As a countermeasure against this, a method of inserting a transparent PET resin film between EVA and ionomer has been proposed (Patent Document 2).

In this method, it is necessary to laminate three layers of ionomer, PET resin film, and EVA between the glass and the cell, and the steps are complicated.

In addition, silicone is exemplified as a sealing material that does not generate PID. It has been reported that the PID phenomenon is less likely to occur in a solar cell module using silicone as an encapsulating material (Non-Patent Document 1).

However, silicone is generally a liquid, and new equipment needs to be invested in order to introduce it into the solar cell module process. In addition, there is a problem of high material cost and an increase in the production cost of the solar cell module.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2014-11246

Patent Document 2: Japanese Patent Laid-Open No. 2014-157874

non-patent literature

Non-Patent Document 1: August Issue of PVeye (2012)

Non-Patent Document 2: P. Hacke et al., "Characterization of Multicrystalline Silicone Modules with System Bias Voltage Applied in Damp Heat", 25th European Photovoltaic Solar Energy Conference and Exhibition, Valensia, Spain, 2010

Contents of the invention

The problem to be solved by the invention

The present invention was made in order to solve the above-mentioned problems, and an object of the present invention is to provide a solar cell module and a method of manufacturing the same, in which the steps of the solar cell module are easy, good lamination sealing is obtained, and PID resistance is excellent.

means to solve the problem

The inventors of the present invention conducted earnest research in order to achieve the above object. As a result, it was found that it is effective to use a laminated body of EVA and silicone for sealing a string of solar cell elements (a plurality of solar cell elements and a connecting body connecting these solar cell elements). of.

That is, the present invention provides the following solar cell module and its manufacturing method.

[1] The solar cell module is a solar cell module having a light-transmitting substrate on the light-receiving surface side and a back protection material on the back side, and is characterized in that it is used as a package between the light-receiving surface-side light-transmitting substrate and the solar cell element The material is a structure in which EVA (ethylene-vinyl acetate copolymer) and silicone are adjacent and laminated, and the structure between the solar cell element and the back protection material is sealed with EVA.

[2] A solar cell module having a light-transmitting substrate on the light-receiving side and a back protection material on the back side, characterized in that it is used as a package between the light-receiving side light-transmitting substrate and the solar cell element The material is a structure in which EVA (ethylene-vinyl acetate copolymer) and silicone are adjacently laminated, and EVA (ethylene-vinyl acetate copolymer) and silicone are adjacently laminated between the back protection material and the solar cell element. up the structure.

[3] The solar cell module described in [1], wherein the EVA is in contact with the light-receiving side light-transmitting substrate, and the adjacent silicone is in contact with the solar cell element.

[4] The solar cell module described in [1], wherein the silicone is in contact with the light-receiving side light-transmitting substrate, and the adjacent EVA is in contact with the solar cell element.

[5] The solar cell module described in [2], wherein EVA is in contact with the light-receiving side light-transmitting substrate and the back protection material, respectively, and the adjacent silicone is in contact with the solar cell element.

[6] The solar cell module described in [2], wherein the silicone is in contact with the light-receiving side light-transmitting substrate and the back protection material, and the adjacent EVA is in contact with the solar cell element.

[7] The solar cell module described in [2] is characterized in that the EVA is in contact with the light-receiving surface side light-transmitting substrate, the silicone adjacent to it is in contact with the light-receiving surface of the solar cell element, and the silicone is in contact with the back protection The material is in contact, and the adjacent EVA is in contact with the back of the solar cell element.

[8] The solar cell module described in [2] is characterized in that the silicone is in contact with the light-receiving surface side light-transmitting substrate, the EVA adjacent thereto is in contact with the light-receiving surface of the solar cell element, and the EVA is in contact with the back protection material. A structure in which the silicone adjacent to it is in contact with the back of the solar cell element.

[9] The solar cell module according to any one of [1] to [8], wherein the above-mentioned EVA and organic silicon form a composite laminate in which EVA and organic silicon overlap to form a two-layer structure, and the thickness of the organic silicon is is 0.05 to 3 mm, and the thickness of the composite laminate is 0.45 to 3.6 mm.

[10] The solar cell module according to any one of [1] to [9], wherein the silicone is a cured product of a silicone composition comprising the following components:

(A) consists of the following average composition formula (I)

R ¹ _a SiO _(4-a)/2 (I)

(In the formula, R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon groups, and a is a positive number from 1.95 to 2.05.)

Organopolysiloxane with a degree of polymerization of 100 or more: 100 parts by mass,

(B) Reinforcing silica having a specific surface area of 50 m ² /g or more: 20 to 150 parts by mass,

(C) Curing agent: The effective amount which hardens (A) component.

[11] The solar cell module according to any one of [1] to [10], which is characterized in that it has a structure using a rear light-transmitting substrate as a rear protection material.

[12] The method for manufacturing a solar cell module according to any one of [1] to [11], wherein the solar cell module is formed as a module by having a light-transmitting substrate on the light-receiving surface side, and using EVA A laminated body stacked with an unvulcanized silicone composition to form a two-layer structure is placed on a light-transmitting substrate, a solar cell element string is placed on the upper part of the laminated body, and an EVA single layer is placed on the back of the solar cell element string, or EVA and unvulcanized silicone composition are stacked to form a laminate with a two-layer structure. After the back protection material is laminated on the backmost side, a vacuum laminator is used to heat and extrude the unvulcanized organic silicon composition under vacuum. Silicon composition and EVA cross-linked.

The effect of the invention

The solar cell module of the present invention can be easily produced using a vacuum laminator without significant fluctuations in the solar cell module manufacturing process, has great resistance to the PID phenomenon, and suppresses the output power of the solar cell module accompanying the PID phenomenon reduce.

Description of drawings

FIG. 1 is a cross-sectional view of a solar cell module according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view of a solar cell module according to a second embodiment of the present invention.

Fig. 3 is a cross-sectional view of a solar cell module according to a third embodiment of the present invention.

Fig. 4 is a cross-sectional view of a solar cell module according to a fourth embodiment of the present invention.

Fig. 5 is a cross-sectional view of a solar cell module according to a fifth embodiment of the present invention.

Fig. 6 is a cross-sectional view of a solar cell module according to a sixth embodiment of the present invention.

Fig. 7 is a cross-sectional view of a solar cell module according to a first comparative example.

Fig. 8 is a cross-sectional view of a solar cell module according to a second comparative example.

9 is a cross-sectional view of a solar cell module according to a third comparative example.

10 is a cross-sectional view of a solar cell module according to a fourth comparative example.

detailed description

The solar cell module according to the present invention has a light-transmitting substrate on the light-receiving surface side, a rear-surface protective material on the back side, and a plurality of solar cell elements are arranged between the light-receiving surface and the back surface, and these plurality of solar cell elements are connected. The solar cell element string composed of connected bodies, the front side sealant for encapsulating the string is filled between the light-transmitting substrate and the solar cell element string, and the back side sealant is filled between the back side protective material and the solar cell element string between.

In this case, the above-mentioned solar cell element can be applied to products including a P-type semiconductor substrate, a product including an N-type semiconductor substrate, and a product including a thin-film element, respectively, and all exhibit effects.

In addition, as the translucent substrate, whiteboard glass, polycarbonate, acrylic board, etc. are used. Among them, soda-lime glass is generally used for whiteboard glass. In soda lime glass, Na ⁺ ions are easily generated. After systemization, if a plurality of solar cell modules are connected in series and a high voltage (negative) load is generated on the cell side, Na ⁺ ions will move to the cell side. , reach the unit surface, recombination occurs, and cause the output power of the solar cell module to decrease, but the present invention has high tolerance to the PID phenomenon and can suppress the decrease in the output power of the solar cell module accompanied by the PID phenomenon, so the whiteboard can be effectively used Glass.

As the back protection material, TPT "PVF (polyvinyl fluoride)/adhesive/PET (polyethylene terephthalate)/adhesive/PVF", TPE "PVF/adhesive/PET/adhesive Adhesive/EVA", or especially a film of a laminate shown in "PVF/adhesive/PET". In addition, as the rear surface protection material, the same light-transmitting substrate as that on the above-mentioned front side can also be used.

In the present invention, a composite laminate of EVA and silicone is used as the front side sealing agent. On the other hand, as the back sealant, EVA may be used alone, or a composite laminate of EVA and silicone may be used as in the front sealant.

In this case, either EVA or silicone may be used on the side of the light-transmitting substrate as the front side sealant. In addition, in the case of using the above-mentioned composite laminate as the back protection material, the difference between EVA and silicone may be used. Either may be located on the back protection material side.

1 to 6 show how such a sealant is arranged. That is, FIG. 1 shows a solar cell module 100 according to the first embodiment of the present invention. From the direction of sunlight incidence, whiteboard glass as a light-transmitting substrate 101, packaging material EVA102, organic silicon 103, and crystalline silicon solar cell element strings are shown. 104. The encapsulation material EVA102 and the back protection material 105 are formed in sequence. These laminates are heated and pressed in a vacuum using a vacuum laminator to be crosslinked and integrated. The solar cell module 100 thus formed was surrounded by an aluminum frame and connected to a grounded metal stand.

In addition, FIG. 2 shows a solar cell module 200 according to a second embodiment of the present invention. From the direction of sunlight incidence, whiteboard glass as a light-transmitting substrate 101, packaging material silicone 103, EVA102, and crystalline silicon solar cell element strings are shown. 104. The encapsulation material EVA102 and the back protection material 105 are formed in sequence.

3 is a solar cell module 300 according to the third embodiment of the present invention. From the incident direction of sunlight, whiteboard glass as a light-transmitting substrate 101, packaging material EVA102, organic silicon 103, crystalline silicon solar cell element strings 104, The encapsulation material EVA102, the silicone 103, and the back surface protection material 105 are constructed in sequence.

4 is a solar cell module 400 according to the fourth embodiment of the present invention. From the direction of sunlight incidence, whiteboard glass as a light-transmitting substrate 101, packaging material silicone 103, EVA102, crystalline silicon solar cell element strings 104, The encapsulation material EVA102, the silicone 103, and the back surface protection material 105 are constructed in sequence.

5 is a solar cell module 500 according to the fifth embodiment of the present invention. From the incident direction of sunlight, whiteboard glass as a light-transmitting substrate 101, packaging material EVA102, organic silicon 103, crystalline silicon solar cell element strings 104, The encapsulating material silicone 103, EVA 102, and back protection material 105 are sequentially constituted.

6 is a solar cell module 600 according to the sixth embodiment of the present invention. From the direction of sunlight incidence, whiteboard glass as a light-transmitting substrate 101, packaging material silicone 103, EVA102, crystalline silicon solar cell element strings 104, The encapsulating material silicone 103, EVA 102, and back protection material 105 are sequentially constituted.

Among them, in the above composite laminate, the thickness of the silicone is preferably 0.05 to 3 mm, particularly preferably 0.1 to 1 mm, and the thickness of the EVA is preferably 0.4 to 0.6 mm. In this case, the thickness of the composite laminate is preferably 0.45 to 3.6 mm, particularly preferably 0.5 to 1.6 mm.

On the other hand, when only EVA is used as the back sealant, the thickness is preferably 0.4 to 0.6 mm.

In the present invention, as EVA (ethylene-vinyl acetate copolymer), EVA generally used in solar cell modules is used, and a commercially available product can be used. As a general EVA, the thing which copolymerized ethylene and vinyl acetate in the mass ratio of 75:25-65:35 is available as a commercial item.

Moreover, in this invention, it is preferable that silicone is obtained by hardening the silicone composition containing following (A)-(C) component.

(A) consists of the following average composition formula (I)

R ¹ _a SiO _(4-a)/2 (I)

(In the formula, R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon groups, and a is a positive number from 1.95 to 2.05.)

Organopolysiloxane with a degree of polymerization of 100 or more: 100 parts by mass,

(B) Reinforcing silica having a specific surface area of 50 m ² /g or more: 20 to 150 parts by mass,

(C) Curing agent: The effective amount which hardens (A) component.

More specifically, the above-mentioned (A) component is an organopolysiloxane having a degree of polymerization represented by the following average composition formula (I) of 100 or more.

R ¹ _a SiO _(4-a)/2 (I)

(In the formula, R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon groups, and a is a positive number from 1.95 to 2.05.)

In the above-mentioned average composition formula (I), R ¹ represents the same or different unsubstituted or substituted monovalent hydrocarbon groups, usually preferably a monovalent hydrocarbon group with 1 to 12 carbon atoms, especially a monovalent hydrocarbon group with 1 to 8 carbon atoms, specifically, Alkyl such as methyl, ethyl, propyl, butyl, hexyl, octyl, cycloalkyl such as cyclopentyl and cyclohexyl, alkenyl such as vinyl, allyl, propenyl, cycloalkenyl, benzene Aryl groups such as radicals, tolyl groups, benzyl groups, aralkyl groups such as 2-phenylethyl groups, or groups in which some or all of the hydrogen atoms in these groups are substituted by halogen atoms or cyano groups, preferably methyl, vinyl radical, phenyl, trifluoropropyl, particularly preferably methyl, vinyl.

Specifically, a product in which the main chain of the organopolysiloxane is composed of dimethylsiloxane repeating units, or a dimethylpolysiloxane composed of dimethylsiloxane repeating units constituting the main chain is preferred. Diphenylsiloxane units, methylphenylsiloxane units, methylvinylsiloxane units having phenyl, vinyl, 3,3,3-trifluoropropyl, etc. Units, products of methyl-3,3,3-trifluoropropylsiloxane units, etc.

In particular, the organopolysiloxane preferably has two or more aliphatic unsaturated groups such as alkenyl groups and cycloalkenyl groups in one molecule, particularly preferably vinyl groups. In this case, preferably 0.01 to 20 mol%, particularly 0.02 to 10 mol%, of all R ¹ are aliphatic unsaturated groups. Furthermore, the aliphatic unsaturated group may be bonded to a silicon atom at the end of the molecular chain, or may be bonded to a silicon atom in the middle of the molecular chain, or both, but is preferably at least bonded to the silicon atom at the end of the molecular chain. Atoms are bonded. In addition, a is a positive number of 1.95 to 2.05, preferably a positive number of 1.98 to 2.02, more preferably a positive number of 1.99 to 2.01.

(A) The organopolysiloxane of the component preferably includes trimethylsiloxy, dimethylphenylsiloxy, dimethylhydroxysiloxy, dimethyl Vinylsiloxy, methyldivinylsiloxy, trivinylsiloxy and other triorganosiloxy-capped products. As particularly preferable organopolysiloxanes, methylvinylpolysiloxane, methylphenylvinylpolysiloxane, methyltrifluoropropylvinylpolysiloxane, and the like are exemplified.

Such an organopolysiloxane can be obtained, for example, by (co)hydrolyzing and condensing one or more organohalosilanes, or by combining a cyclic polysiloxane (trimer, tetramer of siloxane etc.) are obtained by ring-opening polymerization using a basic or acidic catalyst. These are basically straight-chain diorganopolysiloxanes, and may be a mixture of two or more different molecular weights (polymerization degrees) and molecular structures as the component (A).

Furthermore, the degree of polymerization of the organopolysiloxane is 100 or more, preferably 100 to 100,000, particularly preferably 3,000 to 20,000. In addition, this degree of polymerization can be measured as a polystyrene-equivalent weight average degree of polymerization analyzed by gel permeation chromatography (GPC).

(B) Reinforcing silica having a BET specific surface area of 50 m ² /g or more is added in order to obtain a composition excellent in mechanical strength before and after curing. In this case, in order to improve the transparency of the silicone encapsulating material, the BET specific surface area is preferably greater than 200 m ² /g, more preferably greater than 250 m ² /g. When the BET specific surface area is 200 m ² /g or less, the transparency of the cured product may decrease. In addition, the upper limit is not particularly limited, but is usually 500 m ² /g or less.

Examples of the reinforcing silica of such (B) component include fumed silica (dry silica or fumed silica), precipitated silica (wet silica), and the like. In addition, those whose surfaces have been hydrophobized with chlorosilane, alkoxysilane, hexamethyldisilazane, or the like are also preferably used. In particular, the treatment with hexamethyldisilazane is preferable because transparency increases. When transparency is to be improved, it is preferable to use fumed silica as the reinforcing silica. Reinforcing silica may be used individually by 1 type, and may use 2 or more types together.

As the reinforcing silica of the (B) component, commercially available products can be used, for example, AEROSIL series ( Japan AEROSIL (manufactured by Co., Ltd.), Cabosil MS-5, MS-7 (manufactured by Cabot Corporation), REOLOSIL QS-102, 103, MT-10 (manufactured by Tokuyama Co., Ltd.), etc., have no surface treatment or surface hydrophobization treatment (that is, hydrophilic or hydrophobic) fumed silica, Tokusil US-F (manufactured by Tokuyama Co., Ltd.), NIPSIL-SS, NIPSIL-LP (manufactured by Nippon Silica Industry Co., Ltd.), etc. Untreated or surface hydrophobized precipitated silica, etc.

The compounding quantity of the reinforcing silica of component (B) is 20-150 mass parts with respect to 100 mass parts of organopolysiloxanes of (A) component, Preferably it is 30-90 mass parts, More preferably, it is 50 mass parts. ~90 parts by mass. When the compounding quantity of (B) component is too small, the reinforcement effect before and behind hardening cannot be acquired, and the transparency after hardening of the silicone sealing material falls. When too much, dispersion|distribution of silicon dioxide in a silicone encapsulant becomes difficult, and there exists a possibility that the processability to sheet shape may deteriorate.

The curing agent for component (C) is not particularly limited as long as it can cure component (A), but (a) addition reaction (hydrosilylation reaction) type curing widely known as a curing agent for silicone compositions is preferred. agent, that is, a combination of an organohydrogenpolysiloxane (crosslinking agent) and a hydrosilylation reaction catalyst, or (b) an organic peroxide.

The organohydrogenpolysiloxane used as a crosslinking agent in the above (a) addition reaction (hydrosilylation reaction) contains at least two hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule, and can be used Composed of the following average formula (II)

R ² _b H _c SiO _(4-bc)/2 (II)

(wherein, R ² is an unsubstituted or substituted monovalent hydrocarbon group with 1 to 6 carbon atoms, preferably a monovalent hydrocarbon group that does not have an aliphatic unsaturated bond. As specific examples, it is methyl, ethyl, propyl, Alkyl groups such as butyl, pentyl, and hexyl, unsubstituted monovalent hydrocarbon groups such as cyclohexyl, cyclohexenyl, and phenyl, and the above monovalent hydrocarbon groups such as 3,3,3-trifluoropropyl and cyanomethyl A monovalent hydrocarbon group in which at least a part of the hydrogen atoms is substituted by a halogen atom, a substituted alkyl group substituted with a cyano group, etc. b is 0.7 to 2.1, c is 0.01 to 1.0, and b+c satisfies a positive number of 0.8 to 3.0, preferably Specifically, b is 0.8-2.0, c is 0.2-1.0, and b+c is a positive number satisfying 1.0-2.5.)

represents a conventionally known organohydrogenpolysiloxane. In addition, the molecular structure of the organohydrogenpolysiloxane may be any of linear, cyclic, branched, and three-dimensional network structures. In this case, it is preferable to use an organohydrogenpolysiloxane that is liquid at room temperature and has about 2 to 300 silicon atoms (or a degree of polymerization) in one molecule, particularly about 4 to 200. In addition, the hydrogen atom (SiH group) bonded to the silicon atom may be located at the terminal of the molecular chain, may be located at the side chain, or may be located at both, and at least 2 (usually 2 to 300) are used in 1 molecule. , preferably 3 or more (for example, 3 to 200), more preferably 4 to 150 or so SiH-based organohydrogenpolysiloxanes.

Specific examples of the organohydrogenpolysiloxane include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, methyl Hydrocyclopolysiloxane, Methylhydrogensiloxane-Dimethicone Cyclic Copolymer, Tris(Dimethylhydrogensiloxy)methylsilane, Tris(Dimethylhydrogensiloxy) ) phenylsilane, two-terminal trimethylsiloxy-blocked methylhydrogenpolysiloxane, two-terminal trimethylsiloxy-blocked dimethylsiloxane-methylhydrogensiloxane copolymer , two-terminal dimethylhydrogensiloxy-blocked dimethylpolysiloxane, two-terminal dimethylhydrogensiloxy-blocked dimethylsiloxane-methylhydrogensiloxane copolymer, two Terminal trimethylsiloxy-blocked methylhydrogensiloxane-diphenylsiloxane copolymer, both-terminal trimethylsiloxy-blocked methylhydrogensiloxane-diphenylsiloxane -Dimethicone Copolymer, Cyclic Methylhydrogenpolysiloxane, Cyclic Methylhydrogensiloxane-Dimethicone Copolymer, Cyclic Methylhydrogensiloxane-Diphenyl Siloxane-dimethylsiloxane copolymers, copolymers consisting of (CH ₃ ) ₂ HSiO _1/2 units and SiO _4/2 units, copolymers consisting of (CH ₃ ) ₂ HSiO _1/2 units and SiO _4/ Copolymers composed of ₂ units and (C ₆ H ₅ )SiO _3/2 units, etc., products in which part or all of the methyl groups in the above-mentioned exemplified compounds are replaced by other alkyl groups such as ethyl and propyl groups, and aryl groups such as phenyl groups Wait.

The blending amount of the organohydrogenpolysiloxane is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 10 parts by mass, and still more preferably 0.3 to 10 parts by mass.

In addition, the organohydrogenpolysiloxane is preferably blended in such an amount that hydrogen atoms bonded to silicon atoms (that is, SiH groups) in the component (C) are relative to olefins bonded to silicon atoms in the component (A). The molar ratio of the groups is 0.5 to 5 mol/mol, preferably 0.8 to 4 mol/mol, more preferably 1 to 3 mol/mol.

In addition, as the hydrosilylation reaction catalyst used in the crosslinking reaction of the above (a) addition reaction (hydrosilylation reaction), known catalysts can be applied, for example, platinum black, platinum chloride, chloroplatinic acid , Reactants of chloroplatinic acid and monohydric alcohols, complexes of chloroplatinic acid and olefins, platinum-based catalysts such as platinum diacetoacetate, palladium-based catalysts, rhodium-based catalysts, etc. In addition, the blending amount of the hydrosilylation reaction catalyst may be a catalyst amount, and usually, it is preferably in the range of 1 to 1,000 ppm, more preferably in the range of 5 to 100 ppm in terms of the mass of the platinum group metal. If it is less than 1 ppm, there is a possibility that the addition reaction does not proceed sufficiently and curing becomes insufficient, so adding an amount exceeding 1,000 ppm is not economical.

In addition, in addition to the above-mentioned reaction catalysts, in order to adjust the curing speed or pot life, an addition reaction control agent may be used. Specific examples thereof include ethynylcyclohexanol, tetramethyltetravinylcyclotetrasiloxane, and the like.

On the other hand, examples of (b) organic peroxides include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, p-toluyl peroxide, o-formyl peroxide Benzoyl peroxide, 2,4-dicumyl peroxide, 2,5-dimethyl-bis(2,5-tert-butylperoxy)hexane, di-tert-butyl peroxide, benzene peroxide tert-butyl formate, 1,6-hexanediol-bis-tert-butyl peroxycarbonate, etc.

The addition amount of this (b) organic peroxide is 0.1-15 mass parts with respect to 100 mass parts of (A) components, Preferably it is 0.1-15 mass parts, Especially preferably, it is 0.2-10 mass parts. If the amount added is too small, the cross-linking reaction will not proceed sufficiently, and the hardness may decrease and the strength may be insufficient. If it is too large, not only the cost is disadvantageous, but also a large amount of decomposition products of the curing agent may be generated, and the discoloration of the sheet may increase. .

In the silicone composition according to the present invention, in addition to the above-mentioned components, within the range that does not impair the object of the present invention, flame retardancy imparting agents, colorants, carbon functional silanes having alkoxysilyl groups, etc. adhesive.

The silicone composition according to the present invention can be obtained by kneading predetermined amounts of the above-mentioned components with twin rolls, a kneader, a Banbury mixer, or the like.

The plasticity before hardening of the silicone composition prepared in this way is 150-1,000, Preferably it is 200-800, More preferably, it is 250-600. If the degree of plasticity is less than 150, it will be difficult to maintain the shape of the uncured sheet, and it will become sticky and difficult to handle. On the other hand, if it exceeds 1,000, it becomes dry and dry, making the sheeting process difficult. It should be noted that plasticity can be measured in accordance with JIS K 6249.

When molding the unvulcanized silicone composition according to the present invention into a sheet shape, the molding method is not particularly limited, and extrusion molding, calender molding, and the like can be used. In this case, the thickness of the silicone composition sheet is preferably 0.05 to 3 mm.

The silicone composition in an unvulcanized state according to the present invention can be molded by using EVA as a base material and bonding one side of the EVA and the silicone composition together.

For example, as the lamination method of the silicone composition and EVA in the unvulcanized state, the sheets laminated in advance are simultaneously extruded with a roll, or the silicone monolayer is extruded with a roll, and then rolled up in the coiling process. The method of laminating and pasting the middle side and EVA at the same time, etc.

In addition, curing of the silicone composition can be performed by heating at 120 to 150° C. for 20 to 60 minutes.

Here, the method for manufacturing the solar cell module of the present invention will be described. The solar cell module can be a module by having a light-transmitting substrate on the light-receiving surface side, and overlapping EVA and an unvulcanized silicone composition in two layers. The laminated body of the layer structure is placed on a light-transmitting substrate, a solar cell element string is placed on the upper part of the laminated body, and a single layer of EVA is placed on the back of the solar cell element string, or EVA and an unvulcanized silicone composition are stacked to form In the laminate of the two-layer structure, after laminating the back protection material on the backmost side, the silicone composition and EVA in the unvulcanized state are cross-linked by heating and pressing under vacuum using a vacuum laminator.

Example

Examples and comparative examples are shown below to describe the present invention in detail, but the present invention is not limited to the following examples. In addition, the part of the unit of a compounding quantity is a mass part. In addition, the weight average molecular weight and weight average degree of polymerization are polystyrene-equivalent values in gel permeation chromatography (GPC) analysis.

[Example, comparative example]

First, silicones used in Examples and Comparative Examples will be described.

Added an organic polymer consisting of 99.85 mol% of dimethylsiloxane units, 0.025 mol% of methylvinylsiloxane units, and 0.125 mol% of dimethylvinylsiloxane units, with an average degree of polymerization of about 6,000. 100 parts of siloxane, 70 parts of silica (trade name AEROSIL 300, manufactured by Nippon Aerosil Co., Ltd.) with a BET specific surface area of 300 m ² /g, 16 parts of hexamethyldisilazane as a dispersant, 4 parts of water , kneaded with a kneader, and heat-treated at 170° C. for 2 hours to prepare a rubber compound.

With respect to 100 parts of the above rubber compound, C-25A (platinum catalyst)/C-25B (organohydrogenpolysiloxane) (both manufactured by Shin-Etsu Chemical Co., Ltd.) After uniformly mixing 0.5 part/2.0 parts each, a sheet of the silicone composition in an unvulcanized state was produced using a calender roll.

In addition, as the EVA, an EVA sheet for solar cells (rapid curing type) manufactured by Sunbick Co., Ltd. was used, and as a light-transmitting substrate on the surface, whiteboard glass (3.2 mm thick, with a single-sided embossed shape) as the back protection material, using TPT (Tedlar-PET-Tedlar: PTD250) of Emme-Pakkerging Co., Ltd., to produce solar cell modules of Examples and Comparative Examples.

That is, according to the configurations of FIGS. 1 to 6 described above, the solar cell modules 100 to 600 of Examples 1 to 6 were obtained.

In addition, a solar cell module 700 (Comparative Example 1) shown in FIG. 7 was obtained. It is composed of whiteboard glass as translucent substrate 101 , encapsulating material EVA102 , crystalline silicon solar cell element strings 104 , encapsulating material EVA102 , silicone 103 , and back protection material 105 in order from the direction of sunlight incidence.

Fig. 8 is a solar cell module 800 (comparative example 2), according to the whiteboard glass as the light-transmitting substrate 101, the packaging material EVA102, the crystalline silicon solar cell element string 104, the packaging material organic silicon 103, EVA102, the back side from the incident direction of sunlight The protection material 105 is constructed sequentially.

Fig. 9 is a solar cell module 900 (comparative example 3), according to the whiteboard glass as the light-transmitting substrate 101, the packaging material EVA102, the crystalline silicon solar cell element string 104, the packaging material EVA102, and the rear surface protection material 105 from the incident direction of sunlight. sequential composition.

Fig. 10 is a solar cell module 1000 (comparative example 4), according to the whiteboard glass as the light-transmitting substrate 101, the encapsulating material organic silicon 103, the crystalline silicon solar cell element string 104, the encapsulating material organic silicon 103, and the back surface from the sunlight incident direction. The protection material 105 is constructed sequentially.

Wherein, the packaging material EVA102 has a thickness of 0.45mm and is in the shape of a sheet. In addition, the thickness of the packaging material organic silicon 103 is 0.5mm, and the solar cell modules 100-700 are in the shape of a sheet in which the organic silicon 103 and the EVA 102 are integrated. That is, the total thickness of the EVA silicone laminate was 0.95 mm. In the solar cell module 800 , the encapsulation material silicone 103 is a single body with a thickness of 0.5 mm.

In addition, regarding the solar battery module 100 , six types of unvulcanized encapsulating material silicone 103 with a thickness of 0.05, 0.1, 0.25, 0.5, 1, and 3 mm are made, which are integrated with EVA 102 respectively. Therefore, the thicknesses of the packaging material EVA silicone laminates are 0.5, 0.55, 0.7, 0.95, 1.45, and 3.45 mm, respectively.

Next, each step in the manufacture of each solar cell module will be described.

[Production of solar cell modules]

[1] Production of EVA silicone laminate sheet

The above silicone composition is formed into a sheet by calendering. At this time, the thickness of the silicone composition in the unvulcanized state was prepared so that the thickness was 0.05, 0.1, 0.25, 0.5, 1, and 3 mm, and it was molded while pasting EVA as a base material.

On the top of the silicone composition in an unvulcanized state, an embossed film is pressed and formed while protecting the silicone surface.

[2] Configuration of solar cell elements (units)

The solar cell 104 used a 156 mm square p-type single crystal cell for solar cells.

[3] Fabrication of solar cell element (unit) strings

The solar battery cell string 104 is arranged in a quadrangular size (2×2 rows), and is formed by connecting connection wires in series.

[4] Formation of solar cell modules

The solar cell module 100 is taken as an example for description.

EVA-silicon composites (102, 103) are placed on the upper surface of whiteboard glass (light-transmitting substrate 101) such that EVA 102 is arranged on a side in contact with whiteboard glass. The solar battery cell string 104 described above is placed on the silicone 103 , the EVA 102 is placed thereon, and finally the back surface protection material 105 is placed thereon.

The thus-obtained laminate of glass, encapsulant, cell encapsulant, and rear surface protection material was heated and extruded at 140° C. under vacuum with a vacuum laminator to form a solar cell module. When there is no visually confirmed interface between the EVA 102 and the silicone 103, and no wrinkles or undulations occur, lamination sealing can be performed satisfactorily.

After the solar cell module produced through the above process, a frame made of aluminum alloy is installed around it, and edge sealing materials such as silicone are sealed, and finally the corners of the frame are screwed and fixed, and the solar cell module is finally completed.

Next, examples and comparative examples of the PID test are shown.

[PID test]

The solar cell module fabricated as above was tested under an environment of temperature 60° C. and humidity 85% RH with the light-receiving side glass facing down, and the white plate glass on the light-receiving side was immersed in water in a water tank.

A voltage of -1,000 V inside the solar battery cell was applied between the outer aluminum frame and the solar battery cell wiring, and the test was carried out for 96 hours. The output power was measured using a pulse wave IV simulator, measured and compared before and after the test. The measurement test conditions are 25°C and 1,000W/m ² illuminance.

The results are shown in Tables 1 and 2.

[Table 1]

[Table 2]

As shown in Table 1, the output power maintenance rate (initial stage) after the test of the solar cell modules 100, 200, 300, 400, 500, and 600 was found to be within 100±0.2%, and the PID phenomenon was suppressed.

As shown in Table 2, it can be seen that the output power maintenance ratios (initial stage) of the solar cell modules 700 and 800 after the test were 72.6% and 68.9%, respectively, and the PID phenomenon occurred. This result shows that PID cannot be suppressed unless silicone is present between the light-receiving surface side whiteboard glass and the solar cell. In addition, the output maintenance rate (initial stage) of the solar cell module 900 after the test was 60.1%, and the occurrence state of the PID phenomenon was the largest.

The output maintenance rate of the solar cell module 1000 after the test was 100.1%, and the PID phenomenon was suppressed. This structure is considered to have the highest PID resistance of the solar cell module, but there is a problem of solar cell production cost.

In addition, Table 3 shows the evaluation results of changing the thickness of the silicone in the solar cell module 100 .

[table 3]

As shown in Table 3, the output retention rate was 98.0% at 0.05 mm, and 100±0.2% at thicknesses of silicone of 0.1, 0.25, 0.5, 1, and 3 mm. Even if it is 0.05 mm thick, the PID phenomenon suppression effect can be obtained, but it is preferably 0.1 mm thick or more.

From the above, the solar battery module according to the present invention can use a composite of EVA and silicone as a sealing material, and laminate the sealing composite between a transparent substrate made of glass or the like and a solar battery unit. Good lamination sealing can be easily obtained without greatly increasing the production cost of the solar cell module while suppressing the occurrence of PID.

Explanation of reference signs

100, 200, 300, 400, 500, 600, 700, 800, 900, 1000: solar cell modules

101: Translucent substrate

102: Packaging material EVA

103: Encapsulation material silicone

104: solar cell element string

105: Back protection material

Claims (12)

1. solar cell module, be have in light surface side light-transmitting substrate, overleaf side there is back-protective material too Positive energy battery component, it is characterised in that as the encapsulating material between light surface side light-transmitting substrate and solar cell device, The structure for abutting and being laminated for EVA (ethylene-vinyl acetate copolymer) and organosilicon, solar cell device and the back side It is through the sealed structures of EVA between protection materials.

2. solar cell module, be have in light surface side light-transmitting substrate, overleaf side there is back-protective material too Positive energy battery component, it is characterised in that as the encapsulating material between light surface side light-transmitting substrate and solar cell device, The structure for abutting and being laminated for EVA (ethylene-vinyl acetate copolymer) and organosilicon, and overleaf protection materials with Between solar cell device the structure being laminated is abutted for EVA (ethylene-vinyl acetate copolymer) with organosilicon.

3. the solar cell module described in claim 1, it is characterised in that be EVA connect with light surface side light-transmitting substrate, The structure that adjacent organosilicon connects with solar cell device.

4. the solar cell module described in claim 1, it is characterised in that be organosilicon and light surface side light-transmitting substrate phase The structure that the EVA connect, abutted connects with solar cell device.

5. the solar cell module described in claim 2, it is characterised in that be EVA respectively with light surface side light-transmitting substrate The structure that the organosilicon connect with back-protective material, abutted connects with solar cell device respectively.

6. the solar cell module described in claim 2, it is characterised in that be organosilicon respectively with light surface side translucency base The structure that plate and back-protective material connect, adjacent EVA connects with solar cell device respectively.

7. the solar cell module described in claim 2, it is characterised in that be EVA connect with light surface side light-transmitting substrate, The organosilicon being adjacent connects with solar cell device smooth surface and organosilicon connects and it with back-protective material Adjacent EVA and solar cell device back face structure.

8. the solar cell module described in claim 2, it is characterised in that be organosilicon and light surface side light-transmitting substrate phase The EVA connect, being adjacent connects with solar cell device smooth surface and EVA connects with back-protective material, is adjacent Organosilicon and solar cell device back face structure.

9. the solar cell module described in any one of claim 1~8, it is characterised in that above-mentioned EVA is formed with organosilicon EVA is overlapping with organosilicon be 2 Rotating fields compound stack body, the thickness of organosilicon is 0.05~3mm, the thickness of compound stack body Spend for 0.45~3.6mm.

10. the solar cell module described in any one of claim 1~9, it is characterised in that above-mentioned organosilicon is comprising under State the solidfied material of the silicon composition of component：

(A) organopolysiloxane that the degree of polymerization that formula (I) represents is more than 100 is averagely constituted by following：100 mass parts,

R¹ _aSiO_(4-a)/2 (I)

In formula, R¹Identical or different unsubstituted or substituted 1 valency alkyl is represented, a is 1.95~2.05 positive number,

(B) specific surface area is 50m²/ more than g reinforcing silica：20~150 mass parts, and

(C) curing agent：The effective dose for solidifying (A) composition.

11. the solar cell module described in any one of claim 1~10, it is characterised in that to have used back side printing opacity Property substrate as back-protective material structure.

12. the manufacture method of the solar cell module described in any one of claim 1~11, it is characterised in that it is above-mentioned too Positive energy battery component passes through following and turns into component：There is light-transmitting substrate in light surface side, make EVA and unvulcanized state has It is that the layered products of 2 Rotating fields is placed in light-transmitting substrate that machine silicon composition is overlapping, and solar cell is loaded on the layered product top Element string, loads EVA individual layers or EVA and the silicon composition of unvulcanized state on the solar cell device string back side Overlapping is the layered product of 2 Rotating fields, after most rear side has been laminated back-protective material, using vacuum laminator, under vacuo Heating extruding is carried out, makes silicon composition and the EVA crosslinkings of unvulcanized state.