JP2011159779A - Solar cell module, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar cell module having superior long-term reliability, and to provide a method of manufacturing the solar cell module. <P>SOLUTION: The solar cell module 3 includes: a solar cell 1 having a light receiving surface, an opposite surface of the light receiving surface, and electrode wiring provided on the opposite surface; a conductor wiring pattern that is connected to the electrode wiring at a plurality of portions and has sagging in the thickness direction between one connected portion and other connected portion adjacent to the one connected portion; and a sealing part 36 sealing the solar cell 1 and the conductor wiring pattern. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solar cell module and a method for manufacturing a solar cell module. In particular, the present invention relates to a solar cell module using a back contact type solar cell and a method for manufacturing the solar cell module.

  In solar cells, it is required to arrange electrodes at high density in order to reduce loss due to recombination of charge carriers and improve conversion efficiency. For this reason, it is assumed that a frame-shaped wiring obtained by punching copper foil with a press is used for the back surface of the solar battery cell, but one wiring has a length of 100 mm or more and a wiring pitch of 1 mm or less is required. In such a case, it is difficult to maintain the positional relationship between the wirings.

  Therefore, conventionally, a solar cell structure including a plurality of solar cell strings is electrically connected, and the solar cell structure has a portion of a substrate in at least one of opposite ends of the solar cell structure. The solar cell string is installed by being bent on the side opposite to the light receiving surface side, and the solar cell string has a bus bar portion that is a part of the wiring on the bent substrate portion. Solar cell modules that are connected electrically and electrically connected are known (see, for example, Patent Document 1).

  According to the solar cell module described in Patent Document 1, it is possible to cope with the reduction in the thickness of the solar cell and to improve the power generation efficiency and characteristics of the solar cell module.

JP 2009-43842 A

  However, since the solar cell module described in Patent Document 1 is sealed with a base material (for example, a film made of polyimide, polyethylene terephthalate, polyethylene naphthalate, etc.) that is a constituent material of the wiring board, and an adhesive, It is necessary to conduct tests corresponding to the long-term reliability of solar cell modules that require a product life of 10 years or more, or to build up the results in the market. In addition, as a specific example that deteriorates long-term reliability, for example, a base material and an adhesive used for a wiring board are deteriorated by ultraviolet rays, and an adhesive absorbs moisture in the atmosphere and is degraded by hydrolysis. And / or deterioration of the electrical insulation resistance of the encapsulant due to a chemical reaction between the ethylene-vinyl acetate copolymer (EVA) resin and the encapsulant.

  Moreover, since the crystalline solar cell is composed of a single crystal or polycrystal of Si, the linear expansion coefficient of the solar cell is about 3 to 7 ppm. On the other hand, the linear expansion coefficient of copper used for the conductor wiring of the flexible wiring board is about 16 ppm. Therefore, when there is a temperature change due to heating at the time of manufacturing a solar battery module configured using the solar battery cell and the flexible wiring board, or a temperature change at which the manufactured solar battery module is exposed to the market, Stress caused by the difference between the linear expansion coefficient of the battery cell and the linear expansion coefficient of the flexible wiring board is generated in the solar battery cell. The generated stress may cause warpage of the solar battery cell, destruction of the solar battery cell, disconnection of the wiring of the flexible wiring board, or the like.

  Therefore, the objective of this invention is providing the manufacturing method of a solar cell module and solar cell module with favorable long-term reliability.

  In order to achieve the above object, the present invention connects a solar battery cell having a light receiving surface, a surface opposite to the light receiving surface, and an electrode wiring provided on the opposite surface, to the electrode wiring at a plurality of portions. A conductive wiring pattern having a slack in the thickness direction between the connected portion of the first and the other connected portions adjacent to the one connected portion, and the solar battery cell and the conductive wiring pattern There is provided a solar cell module including a sealing portion for sealing.

  In the solar cell module, the sag may be a sag that is convex or concave toward the solar cell side.

  Further, in the solar cell module, the sagging is 1.0% or more of the distance between one connected portion and another connected portion in the thickness direction of the solar battery cell (however, 25 Sag) (in degrees Celsius).

  In the solar cell module, the conductor wiring pattern may include copper or a copper alloy and have a thickness of 18 μm or more and 75 μm or less.

  Moreover, the said solar cell module WHEREIN: The rolled foil whose 0.2% yield strength is 100 Mpa or less may be sufficient as copper or a copper alloy.

  In the above solar cell module, the conductor wiring pattern may have a surface having a surface roughness of 10 μm or less in terms of 10-point average roughness.

  In the solar cell module, the conductor wiring pattern may be a wiring pattern included in the flexible wiring board.

  In order to achieve the above object, the present invention provides a cell preparation step for preparing a solar cell having electrode wiring, a wiring for preparing a wiring board having a base material, and a wiring pattern provided above the base material. A substrate preparation step, a wiring pattern and electrode wiring are connected at a plurality of portions, a mounting step of mounting the solar cell on the wiring substrate, a base material is removed, the wiring pattern is exposed, and the wiring pattern and electrode wiring And an exposure step of forming a wiring pattern having a slack in the thickness direction between the one connected portion and the other connected portion adjacent to the one connected portion. A method for manufacturing a solar cell module is provided.

  Moreover, in the manufacturing method of the said solar cell module, a cell preparation process can prepare the back contact type photovoltaic cell which has a light-receiving surface in one surface, and has electrode wiring in the other surface.

  According to the solar cell module and the solar cell module manufacturing method according to the present invention, it is possible to provide a solar cell module and a solar cell module manufacturing method with good long-term reliability.

It is the top view which looked at the photovoltaic cell with which the solar cell module which concerns on embodiment of this invention is provided from the back surface. (A) is a top view of the flexible wiring board used for manufacture of the solar cell module which concerns on embodiment of this invention, (b) is sectional drawing in the AA of (a). It is sectional drawing of the solar cell module which concerns on embodiment of this invention. It is a fragmentary sectional enlarged view of the solar cell module which concerns on embodiment of this invention. It is a fragmentary sectional enlarged view of the solar cell module which concerns on the modification of embodiment of this invention. It is a figure which shows the flow of manufacture of the solar cell module which concerns on embodiment of this invention. (A) And (b) is a figure which shows the flow of manufacture of the solar cell module which concerns on embodiment of this invention. It is a figure which shows the flow of manufacture of the solar cell module which concerns on embodiment of this invention. It is a figure which shows the flow of manufacture of the solar cell module which concerns on embodiment of this invention.

[Summary of embodiment]
In the solar cell module in which the conductor wiring is connected to the back surface of the back contact type solar cell, a solar cell having a light receiving surface, a surface opposite to the light receiving surface, and an electrode wiring provided on the opposite surface; A plurality of portions are connected to the electrode wiring, and there is a slack in the thickness direction between one connected portion and another connected portion adjacent to the one connected portion. There is provided a solar cell module including a conductor wiring pattern and a sealing portion that seals the solar battery cell and the conductor wiring pattern.

[Embodiment]
FIG. 1: shows the top view which looked at the photovoltaic cell with which the solar cell module which concerns on embodiment of this invention is provided from the back surface.

(Solar cell 1)
The solar battery cell 1 included in the solar battery module 3 according to the present embodiment includes, for example, a semiconductor substrate 14 and electrode wiring mainly formed from single crystal silicon. That is, the solar cell 1 has a semiconductor substrate 14 formed in a flat plate shape from a predetermined semiconductor material. The semiconductor substrate 14 has a light receiving surface (that is, a surface) on one surface and the other surface (that is, a surface). , Back surface). Specifically, the solar battery cell 1 according to the present embodiment is a back contact solar battery cell 1, and no electrode wiring is provided on the light receiving surface. Moreover, the electrode wiring has the p electrode 10 and the n electrode 12, and the p electrode 10 and the n electrode 12 are each formed in a comb-tooth shape. Further, the comb-shaped p-electrode 10 and the comb-shaped n-electrode 12 are provided so as to mesh with each other on the other surface of the solar battery cell 1.

  Further, in the present embodiment, a plurality of p-side thin wire electrodes 10b, which are comb teeth of the p electrode 10, and a plurality of n-side thin wire electrodes 12b, which are comb teeth of the n electrode 12, are continuously formed linearly in this embodiment. Is done. The p-side thin wire electrode 10b is formed so as to extend from the p-side outer electrode 10a provided in the vicinity of the one side to the opposite side of the one side in a plan view. . Similarly, the n-side thin wire electrode 12b is provided in the vicinity of the opposite side of the one side, and is formed to extend from the n-side outer electrode 12a provided in parallel to the opposite side to the one side.

  The electrode wiring (that is, the p-electrode 10 and the n-electrode 12) can be formed using a material having good conductivity and good connectivity to solder as a main component. For example, the electrode wiring can be formed using silver as a main component. In addition, a conductive adhesive layer such as a silver paste can be printed on the surface of the electrode wiring. Note that the p-side thin wire electrode 10b and the n-side thin wire electrode 12b can each be formed discontinuously in a dotted line shape.

  In addition, the photovoltaic cell 1 can also be mainly formed from a polycrystalline silicon. Moreover, the photovoltaic cell 1 can also be mainly formed from another semiconductor, for example, a III-V group compound semiconductor. Furthermore, the arrangement of the p-electrode 10 and the n-electrode 12 can be reversed from the arrangement of the present embodiment.

(Flexible wiring board 2)
Fig.2 (a) shows the top view of the flexible wiring board used for manufacture of the solar cell module which concerns on embodiment of this invention, FIG.2 (b) is the cross section in the AA of Fig.2 (a). Indicates.

  A flexible wiring substrate 2 as a solar cell wiring substrate (that is, a wiring substrate) used for manufacturing the solar cell module 3 according to the present embodiment is provided above the base material 20 having flexibility and the base material 20. In addition to having a conductor wiring pattern (that is, the p-side electrode 24 and the n-side electrode 26) as a wiring pattern to be formed, an adhesive layer 22 is provided between the substrate 20 and the conductor wiring pattern. The adhesive layer 22 is provided on substantially the entire surface or a part of the surface of the substrate 20. The adhesive layer 22 can be provided with an epoxy adhesive by coating or laminating. As the adhesive, for example, an adhesive T (manufactured by Arisawa Manufacturing Co., Ltd.) can be used.

(Substrate 20)
The base material 20 is mainly formed from a flexible insulating material, and is formed in a film shape. The base material 20 is formed to have a thickness of 10 μm or more and 125 μm or less, preferably 25 μm or more and 75 μm or less from the viewpoint of easy handling. As an insulating material which comprises the base material 20, a polyethylene terephthalate (PET), a polyethylene naphthalate (PEN), a polyimide, a polyamideimide etc. can be used, for example.

(Adhesive layer 22)
The adhesive layer 22 is mainly formed from an adhesive composition whose adhesive strength is reduced by supplying energy. As the adhesive composition, a resin material such as an epoxy resin or an acrylic resin can be used. Examples of the energy supply include supply of heat energy by heating and supply of light energy by irradiation with ultraviolet rays (UV). That is, the adhesive layer 22 is mainly composed of an adhesive composition that reduces the adhesive strength of the conductor wiring pattern to the adhesive layer 22 when a predetermined energy is supplied to the flexible wiring substrate 2.

(Conductor wiring pattern)
The conductor wiring pattern is mainly formed from, for example, copper or a copper alloy. In addition, the conductor wiring pattern is preferably formed to have a thickness of 18 μm or more and 75 μm or less from the viewpoint of reducing direct current resistance and stress generated based on temperature change. Further, in the environment where the temperature changes, the 0.2% proof stress of the conductor wiring pattern is annealed for the purpose of reducing the stress generated in the solar battery cell 1 provided in the solar battery module 3 according to the present embodiment. It is preferable to reduce to about 100 MPa or less by performing a treatment or the like. Therefore, the conductor wiring pattern is preferably formed from a rolled foil of a metal material.

  Furthermore, the conductor wiring pattern has a surface roughness with a 10-point average roughness of 1.0 μm or less on the surface roughness of at least the surface in contact with the adhesive layer 22 for the purpose of facilitating the peeling of the adhesive layer 22 from the conductor wiring pattern. It is preferable. For the purpose of preventing discoloration of the conductor wiring pattern, preventing corrosion of the conductor wiring pattern, and improving the reliability of electrical connection of the conductor wiring pattern to the electrode wiring of the solar battery cell 1, gold, A plating treatment containing tin, nickel, cobalt, chromium, or the like can also be performed.

  Specifically, the conductor wiring pattern is provided in a comb-teeth shape on the surface of the adhesive layer 22, and includes a p-side electrode 24 as a p-type first wiring as a first conductivity type, and a p-side electrode 24. An n-side electrode 26 serving as a second wiring for n-type serving as a second conductivity type different from the p-type is provided on the surface of the adhesive layer 22 different from the provided region. Specifically, the p-side fine wire electrode 24a, which is a comb tooth of the p-side electrode 24, and the n-side thin wire electrode 26a, which is a comb tooth of the n-side electrode 26, are alternately arranged.

  In FIG. 2, a layout in which two solar cells 1 are mounted on the flexible wiring board 2 is shown as an example. In the modification of the present embodiment, a flexible wiring board 2 having a layout in which three or more solar cells 1 can be mounted can be used. Moreover, the space | interval between the photovoltaic cells 1 and the shape of the conductor wiring pattern between the photovoltaic cells 1 can be designed freely. In addition, it is preferable to set the space | interval between the photovoltaic cells 1 to 1 mm or more for the purpose of preventing that the photovoltaic cells 1 contact and damage. Furthermore, it is preferable to form a recognition pattern and / or a recognition hole for use in positioning and mounting the solar battery cell 1 on the flexible wiring board 2.

  The flexible wiring board 2 can be manufactured as follows. First, a rolled copper foil as a rolled foil is obtained from a rolled foil manufacturer (for example, Hitachi Cable, Ltd.). In this case, the rolled copper foil is annealed so that the 0.2% proof stress is, for example, 100 MPa or less in advance. In addition, the surface of the rolled copper foil can be subjected to surface treatment (for example, oil cleaning, adjustment of rolling roughness, etc.). Further, the rolled copper foil can be subjected to treatments such as degreasing treatment, acid cleaning treatment, roughening treatment, organic solderability preservative (OSP), plating, and the like.

  Next, this rolled copper foil is used for lamination by a Copper Clad Lamination (CCL) material manufacturer. For example, at Arisawa Manufacturing Co., Ltd., the rolled copper foil is laminated to the PEN substrate using the adhesive T (trade name) manufactured by the company. Thereby, a CCL material is obtained. Subsequently, the CCL material is slit to a desired width as necessary. Then, for example, a resist pattern is formed on the surface of the processed CCL material by screen printing or photolithography. Then, a wet etching process is performed on the CCL material using a resist pattern formed by screen printing or photolithography as a mask. Thereby, the flexible wiring board 2 is obtained. The conductor wiring pattern of the obtained flexible wiring board 2 can be plated.

(Solar cell module 3)
FIG. 3A shows a cross section of the solar cell module according to the embodiment of the present invention.

  The solar battery module 3 according to the present embodiment includes the solar battery cell 1 and a conductor wiring pattern that has a base material 20 and an adhesive layer 22 removed from the flexible wiring board 2 and has slack. Specifically, the solar cell module 3 according to the present embodiment includes the solar cell 1, the p-electrode 10 and the n-electrode 12 of the solar cell 1, and the p-side electrode 24 that the flexible wiring board 2 has. A conductive adhesive 40 that electrically connects the n-side electrode 26, a solar cell 1, a p-side electrode 24, a sealing portion 36 that seals the n-side electrode 26, and the solar cell 1 The transparent adhesive sheet 32 provided on the light receiving surface, the glass plate 30 provided on the opposite side of the solar cell 1 of the transparent adhesive sheet 32, and the opposite of the solar cell 1 of the p-side electrode 24 and the n-side electrode 26. And a back sheet 34 provided on the side.

  The solar cell module 3 includes a wiring portion 38 that is electrically connected to the p-side electrode 24 and the n-side electrode 26, an external connection cable 52 that is electrically connected to the wiring portion 38, and an external connection cable 52. An external connection box 50 for storing a part thereof and a metal frame 60 for sandwiching the glass plate 30 and the back sheet 34 are provided.

  FIG. 3B shows an enlarged partial cross-sectional view of the solar cell module according to the embodiment of the present invention. 3B, illustration of the back sheet 34, the sealing part 36, etc. is abbreviate | omitted for convenience of explanation.

  The conductor wiring pattern is electrically connected to the solar battery cell 1 at a plurality of portions via the conductive adhesive 40 in the cross-sectional view. The conductor wiring pattern has a slack in the thickness direction of the solar battery cell 1 between the portions electrically connected to the solar battery cell 1. Specifically, from one contact portion 40a between the conductive wiring pattern (that is, the p-side electrode 24 and the n-side electrode 26) and the conductive adhesive 40, another contact portion 40b adjacent to the one contact portion 40a. The section distance of the section up to is “S”. And as shown to (a) of FIG. 3B, a conductor wiring pattern has a slack so that it may become convex between the one contact part 40a and the other contact part 40b toward the photovoltaic cell 1 side. Alternatively, as shown in FIG. 3B (b), there is a slack between the one contact portion 40a and the other contact portion 40b that becomes concave toward the solar cell 1 side. Furthermore, in the present embodiment, the conductor wiring pattern has a sag “D” of 1.0% or more of the section distance “S” (however, it is “sag” at 25 ° C.).

(About sagging “D”)
The inventor assumes that the solar cell module 3 is installed in a temperature environment in the range of 25 ° C. to ± 65 ° C., and among the stresses generated in the solar cells 1, the stresses generated by the contraction of the conductor wiring pattern It has been found that by canceling about 1/3 of the solar cell module 3, it is possible to realize a long-term stable solar cell module 3 with respect to changes in the temperature environment. That is, it has been found that it is preferable to provide the conductor wiring pattern with a sag of 1.0% or more of the section distance “S” at 25 ° C. in order to realize a long-term stable solar cell module 3.

  In this case, on the basis of 25 ° C., when the solar cell module 3 is installed in a temperature environment of 0 ° C. or higher, the stress generated in the solar cell 1 is canceled before installation in the temperature environment. . Further, when the solar cell module 3 is installed in a temperature environment of −40 ° C., the stress generated in the temperature range of 25 ° C. is canceled in advance before installation in the temperature environment of −40 ° C. . Therefore, compared with the solar cell module which does not have a slack, the stress which generate | occur | produces in the photovoltaic cell 1 can be restrained to the magnitude | size of a stress comparable as the stress generate | occur | produced at the time of -15 degreeC.

  Such a slack “D” is preferably 1.0% or more of the section distance “S” as described above. This value is calculated from the following calculation.

  First, when a parabolic ideal slack “D” exists in the section, the actual length L of the conductor wiring pattern of the section distance “S” can be expressed by the following equation.

L = S + L1 = S + (8D ² ) / (3S) (1)

  However, S is a section distance, D is slack, L is an actual length, and L1 is an extra length.

From the equation (1), the extra length L1 is L1 = (8D ² ) / (3S) (Equation 2).

The difference between the thermal expansion coefficient of the solar battery cell 1 and the thermal expansion coefficient of the conductor wiring pattern when the environmental temperature where the solar battery module 3 is installed changes from 25 ° C. to 0 ° C. (that is, a temperature difference of 25 ° C.) is 10 ppm. Then, when the temperature of the solar cell 1 is changed from 25 ° C. to 0 ° C., the amount that the conductor wiring pattern contracts due to the contraction of the solar cell 1 at the section distance “S” is “25 × 10E ⁻⁶ × S. = 2.5E ⁻⁴ × S ”. When the slack “D” is calculated by substituting this into the equation (2), this is “D = 0.010S”.

  From the above, under the ideal conditions, even if a temperature change from 25 ° C. to 0 ° C. occurs by giving a slack of “D = 0.010S” to the conductor wiring pattern in advance, Generation of stress due to contraction of the conductor wiring pattern can be prevented between the other contact portions 40b.

  FIG. 3C shows an enlarged partial cross-sectional view of a solar cell module according to a modification of the embodiment of the present invention.

  As shown in FIG. 3C, a portion where the conductive wiring pattern (that is, the p-side electrode 24 and the n-side electrode 26) and the conductive adhesive 40 are not in contact can be filled with a sealing material 45. As the sealing material 45, a conductive adhesive, a conductive adhesive, or a solder material can be used.

  Hereinafter, the structure of the solar cell module 3 according to the present embodiment will be further described together with the description of the manufacturing process of the solar cell module 3.

(Manufacturing process of solar cell module 3)
4, FIG. 5, FIG. 6A, and FIG. 6B show an example of the flow of manufacturing the solar cell module according to the embodiment of the present invention.

  Specifically, FIG. 4 shows an outline of a process for mounting solar cells on a flexible wiring board. FIG. 5A shows a plan view of a state in which a solar cell is mounted on a flexible wiring board, and FIG. 5B shows a cross section taken along line BB in FIG. In addition, Fig.5 (a) is a figure from the surface side of the base material in which the photovoltaic cell is not mounted.

(Cell preparation process, wiring board preparation process, mounting process)
First, after preparing the solar battery cell 1 and the flexible wiring board 2 (cell preparation process, wiring board preparation process), the solar battery cell 1 is mounted on the flexible wiring board 2 (mounting process). Specifically, the p-electrode 10 of the solar battery cell 1 is electrically connected to the p-side electrode 24 that is the wiring pattern of the flexible wiring board 2, and the n-side electrode 26 that is the wiring pattern of the flexible wiring board 2. Solar cell 1 is mounted on flexible wiring board 2 such that n electrode 12 of solar cell 1 is electrically connected.

  Here, in the mounting process according to the present embodiment, the p-electrode 10 and the n-electrode 12 are electrically connected to a part of the wiring pattern (that is, the p-side electrode 24 and the n-side electrode 26). Specifically, in the mounting process, on the wiring pattern, the connection portion 15 where the wiring pattern and the p electrode 10 and the n electrode 12 are electrically connected, and the wiring pattern, the p electrode 10 and the n electrode 12 are physically connected. The solar battery cell 1 is mounted on the flexible wiring board 2 so that the non-connecting portion 16 that does not contact is formed.

  For example, as shown in FIG. 5B, a portion where the p-electrode 10 and the p-side electrode 24 are electrically connected partially (or intermittently) using a conductive adhesive 40 is a connecting portion 15. The portion that is formed between one connection portion 15 and another connection portion 15 adjacent to the one connection portion 15 and separates the p-electrode 10 and the p-side electrode 24 is a non-connection portion 16. is there. Therefore, the connection part 15 and the non-connection part 16 are provided alternately. The same applies to the n-electrode 12 and the n-side electrode 26. In addition, the non-connection part 16 is filled with sealing resin which comprises the sealing part 36 mentioned later, for example.

  Here, the conductive adhesive 40 is formed by printing in advance on the surfaces of the p-electrode 10 and the n-electrode 12 of the solar battery cell 1 or the surfaces of the p-side electrode 24 and the n-side electrode 26 of the flexible wiring board 2. . Then, using a technique such as image recognition, the solar battery cell 1 and the flexible wiring board 2 are aligned with each other, and the solar battery cell 1 is mounted on the flexible wiring board 2. Thereby, as shown in FIG. 5, the solar cell string 4 in which the several photovoltaic cell 1 was connected in series is formed.

  In addition, when mounting the photovoltaic cell 1 on the flexible wiring board 2, the flexible wiring board 2 can be formed in a strip-like sheet or a roll shape. When the roll-shaped flexible wiring board 2 is used, the solar cell string is cut out as a sheet or a string before or after the solar cell 1 is mounted for each length of the solar cell 1 to be mounted. 4 can be formed.

  Moreover, the reason for providing the connection part 15 and the non-connection part 16 on the wiring pattern is to prevent the solar battery cell 1 from being warped, thereby causing damage to the solar battery cell 1 and the manufacturing process of the solar battery module 3. This is to prevent deterioration in workability. Therefore, it is preferable to adjust the space | interval of the connection part 15 according to the change of the thickness of the photovoltaic cell 1, and the structure of the flexible wiring board 2. FIG. Moreover, when mounting the photovoltaic cell 1 on the flexible wiring board 2 via the conductive adhesive 40, only the portion of the conductive adhesive 40 is heated or only the solar cell 1 side is heated. And the curvature of the photovoltaic cell 1 can be reduced.

  FIG. 6A (a) shows an outline of a cross-section in a state where a glass plate is attached to a solar cell string via a transparent adhesive sheet, and FIG. 6A (b) is in the process of peeling the base material and the adhesive layer of the flexible wiring board. The outline of the cross section in is shown. FIG. 6B shows an outline of a cross section after the base material and the adhesive layer of the flexible wiring board are peeled from the solar cell string.

(Attaching process)
First, a glass plate 30 having a transparent adhesive sheet 32 attached to one surface is prepared. And the surface of the semiconductor substrate 14 of the solar cell string 4 is affixed on the surface on the opposite side of the glass plate 30 of the transparent adhesive sheet 32 (adhesion process). Specifically, the transparent adhesive sheet 32 is mainly formed from a polyethylene-vinyl acetate (EVA) -based or silicone-based resin. Moreover, the transparent adhesive sheet 32 can also have a wavelength conversion function which converts light having a short wavelength out of sunlight into a wavelength that can be generated in the solar battery cell 1. And the solar cell string 4 is arrange | positioned on the surface on the opposite side to the glass plate 30 of the transparent adhesive sheet 32 on which the glass plate 30 was affixed, and the transparent adhesive sheet 32 and the photovoltaic cell 1 are closely_contact | adhered or adhere | attached. In addition, when the adhesive force of the transparent adhesive sheet 32 and the photovoltaic cell 1 is inadequate, the adhesive force can also be improved by heating and / or pressurizing the transparent adhesive sheet 32.

(Exposure process)
Then, as shown in FIG. 6A (b), by removing the base material 20 from the surfaces of the p-side electrode 24 and the n-side electrode 26 as wiring patterns, the p-side electrode 24 and the n-side having slackness are obtained. The back surface of the electrode for electrode 26, that is, the surface opposite to the surfaces of the p-side electrode 24 and the n-side electrode 26 connected to the p-electrode 10 and the n-electrode 12 as electrode wiring is exposed (exposure process). In the exposing step, the back surface of the p-side electrode 24 and the n-side electrode 26 is removed by peeling off the base material 20 or the base material 20 and the adhesive layer 22 from the surfaces of the p-side electrode 24 and the n-side electrode 26. Expose.

  Specifically, the exposing step is a heating step of heating the flexible wiring substrate 2 and / or the adhesive layer 22 with hot air or the like according to the characteristics of the adhesive composition constituting the adhesive layer 22 of the flexible wiring substrate 2, or There is an irradiation step of irradiating the flexible wiring board 2 and / or the adhesive layer 22 with ultraviolet rays (UV). Then, in the exposure step, the adhesive layer 22 and the base material 20 whose adhesive strength has been reduced by the heating step or the irradiation step are peeled off from the p-side electrode 24 and the n-side electrode 26 as shown in FIG. 6A (b). Thus, the back surfaces of the p-side electrode 24 and the n-side electrode 26 having slack are exposed. Note that the amount of sag is adjusted by adjusting the degree of decrease in adhesive strength in the heating step or the irradiation step.

  More specifically, the exposure step includes a heating step or an irradiation step as a step of supplying a predetermined amount of energy directly or indirectly to the adhesive layer 22 of the flexible wiring board 2. For example, the heating step may be a step of heating the flexible wiring board 2 or a step of heating the adhesive layer 22 by irradiating the adhesive layer 22 with infrared rays. In the exposure step, the base material 20 and the adhesive layer 22 are peeled off from the p-side electrode 24 and the n-side electrode 26 after the adhesive force of the adhesive layer 22 is reduced or reduced. Thereby, as shown in FIG. 6B, the solar cell string 4 having a form in which the base material 20 and the adhesive layer 22 are removed is formed on the glass plate 30 and the transparent adhesive sheet 32.

  The base material 20 and the adhesive layer 22 are peeled off by peeling the base material 20 and the adhesive layer 22 in the direction of an angle of 150 degrees or more and 180 degrees or less with respect to the surface of the glass plate 30. And the influence exerted on the adhesion or adhesion state between the solar battery cell 1 and the solar battery cell 1 can be reduced. In particular, at the start of peeling of the base material 20 and the adhesive layer 22, a portion where the p-side electrode 24 and the n-side electrode 26 and the p-electrode 10 and the n-electrode 12 are not connected is clamped or the like. It can also be fixed.

  In addition, the wiring substrate preparation step includes a wiring pattern (that is, the p-side electrode 24 and the n-side) on the adhesive layer 22 during or after the adhesive layer 22 is heated or after the adhesive layer 22 is irradiated with ultraviolet rays (UV light). It is preferable to prepare the flexible wiring board 2 having the adhesive layer 22 in which the peel strength of the electrode 26) (however, the peel strength of 90 degrees and the tensile speed of 20 mm / min) is 100 N / m or less.

  Further, when the heating temperature in the heating process is lowered, the peel strength between the p-side electrode 24 and the n-side electrode 26 and the adhesive layer 22 increases. When the peel strength is increased and the adhesive layer 22 and the substrate 20 are peeled off from the p-side electrode 24 and the n-side electrode 26 as shown in FIG. 6A (b), as shown in FIG. 3B (b). A slack is formed between the one contact portion 40a and the other contact portion 40b so as to be concave toward the solar battery cell 1 side. This sagging sagging is caused by the fact that the actual length of the connection section of the electrodes 24 and 26 of the flexible wiring board 2 is longer than the connection section distance “S”. Therefore, if there is a clearance from the solar battery cell 1 side. By pressing with a slight force, you can make a convex slack.

(Washing process)
After the base material 20 and the adhesive layer 22 are peeled off from the p-side electrode 24 and the n-side electrode 26, the back surfaces of the p-side electrode 24 and the n-side electrode 26 may be cleaned using atmospheric pressure plasma or the like. Yes (cleaning process). In addition, after peeling off the base material 20 and the adhesive layer 22 from the p-side electrode 24 and the n-side electrode 26, the back surfaces of the p-side electrode 24 and the n-side electrode 26, that is, the base material 20 and the adhesive layer 22. Conductive adhesive on the surfaces of the p-side electrode 24 and the n-side electrode 26 exposed to the outside by peeling off (that is, the surface opposite to the surface to which the conductive adhesive 40 is connected), Alternatively, solder paste or the like can be applied and printed. Then, the conductive adhesive is melted by heating the region where the conductive adhesive or the like is applied and printed, and the melted conductive adhesive or the like is used for the p-side electrode 24 and the n-side electrode 26. The p-side electrode 24 and the n-side electrode 26 are caused to flow from the back side to the front surface (that is, the surface to which the conductive adhesive 40 of the p-side electrode 24 and the n-side electrode 26 is connected). The connection strength between the p electrode 10 and the n electrode 12 can be improved. Thereby, when the connection strength between the p-side electrode 24 and the n-side electrode 26 and the p-electrode 10 and the n-electrode 12 is insufficient, the connection strength can be supplemented.

(Module formation process)
Subsequently, a wiring portion as a wiring member and an external connection wiring member (not shown) are attached to the solar cell string 4. Then, a sealing resin such as polyethylene-vinyl acetate (EVA resin) is used as a coating material, and the solar cell 1, the p-side electrode 24, and the n-side electrode 26 are sealed to form a sealing portion 36. (Sealing process). Further, the back sheet 34 is overlapped on the surface of the sealing portion 36 and deaerated and heated. Thereafter, for example, a metal frame 60 made of aluminum, an external connection box 50, and an external connection cable 52 are attached. Thereby, the solar cell module 3 which concerns on this Embodiment as shown to FIG. 3A is obtained.

(Modification)
In the stage of preparing the flexible wiring board 2 (that is, the wiring board preparation step), by preparing the flexible wiring board 2 that has been embossed to be embossed at room temperature or under heating, A sag in the thickness direction can be formed. Further, as can be seen from FIG. 6A (b), a slack can also be formed between the solar cells 1 and the solar cells 1.

  In FIG. 4, the wiring pattern of the wiring board 2 is comb-shaped, but a part of a straight portion of one comb tooth can be intermittently formed, such as a dotted line or an alternate long and short dash line. In this case, it is possible to electrically connect the solar cells 1 by electrically connecting the portions of the comb teeth that exist intermittently with the conductive paste. Further, in FIG. 4, wiring patterns provided between the solar cells 1 of the wiring substrate 2 (that is, the p-side fine wire electrode 24a of the p-side electrode 24 and the n-side thin wire electrode 26a of the n-side electrode 26 and the like). The region excluding) is a rectangular solid pattern, but a hole or a hole having an arbitrary shape can be provided for the purpose of improving the resin sealing property. For example, a hole penetrating the base material 20 and the adhesive layer 22 or a base material 20 and the adhesive layer 22 are penetrated in a portion where the p-side electrode 24 and the n-side electrode 26 and the solar battery cell 1 do not overlap in plan view. Holes that do not work can be provided.

  In the present embodiment, the solar cells 1 are arranged in a row on the flexible wiring substrate 2, but a flexible wiring substrate in which two or more rows of solar cells are arranged can also be used. When arranging two or more rows of solar cells 1, the conductor wiring pattern of the flexible wiring board can be shaped so as not to electrically connect the rows. In this case, each column can be electrically connected separately using a wiring material. Moreover, the conductor wiring pattern of a flexible wiring board can also be made into the pattern in which the several photovoltaic cell 1 is arrange | positioned electrically in series, or is arrange | positioned in parallel. When the conductor wiring pattern is an electrically parallel pattern, the pattern at a predetermined location can be removed by punching or the like, and can be changed to an electrically serial pattern using a separate wiring material.

  Further, in the production of the flexible wiring board 2, after the plating treatment is applied to one or both sides of the rolled copper foil, a film base material is pasted, and then the rolled copper foil is patterned by etching, and further, the remaining rolled copper foil is applied to the remaining rolled copper foil. The coating can also be applied by plating or soldering. Thereby, when the constituent material of the flexible wiring board 2 is peeled off while leaving the conductor wiring pattern, the back surfaces of the p-side electrode 24 and the n-side electrode 26 whose entire surfaces are plated or solder coated can be exposed.

(Effect of embodiment)
The solar cell module 3 according to the present embodiment can realize the solar cell module 3 having a simple configuration by removing the base material 20 and the adhesive layer 22 from the flexible wiring board 2, and the solar cell module 3. Can be made thinner. In the sealing portion 36, the p-side electrode 24 and the n-side electrode 26 and the solar battery cell 1 are mainly sealed, and the base material 20 and the adhesive layer 22 are not sealed, And since the conductor wiring pattern which has a predetermined | prescribed slack is provided, the inside of the photovoltaic cell 1 resulting from the difference of the linear expansion coefficient of the base material 20, the linear expansion coefficient of the contact bonding layer 22, and the linear expansion coefficient of the photovoltaic cell 1 is provided. It is possible to prevent the occurrence of stress in Therefore, according to the solar cell module 3 according to the present embodiment, when the temperature of the environment in which the solar cell module 3 is installed changes from the normal temperature to the minus side, the stress generated in the solar cell 1 is reduced. Can do. Thereby, since the curvature of the photovoltaic cell 1 and the stress which generate | occur | produces in the photovoltaic cell 1 can be reduced with respect to the change of temperature environment, the solar cell module 3 stable for a long term can be provided.

  Moreover, since the solar cell module 3 according to the present embodiment is manufactured by using the flexible wiring board 2 having a conductor wiring pattern made of rolled foil, the solar cell module is compared with a case where an electrolytic copper foil is used for the conductor wiring pattern. Generation | occurrence | production of the stress in the photovoltaic cell 1 resulting from the difference of the linear expansion coefficient of the cell 1 and the linear expansion coefficient of a conductor wiring pattern can be suppressed.

  While the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. In addition, it should be noted that not all the combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 1 Solar cell 2 Flexible wiring board 3 Solar cell module 4 Solar cell string 10 p electrode 10a p side outer electrode 10b p side thin wire electrode 12 n electrode 12a n side outer electrode 12b n side thin wire electrode 14 Semiconductor substrate 15 Connection part 16 Non Connection part 20 Substrate 22 Adhesive layer 24 P-side electrode 24a P-side fine wire electrode 26 N-side electrode 26a N-side fine wire electrode 30 Glass plate 32 Transparent adhesive sheet 34 Back sheet 36 Sealing part 38 Wiring part 40 Conductivity Adhesive 45 Sealing material 50 External connection box 52 External connection cable 60 Metal frame

Claims (9)

A solar cell having a light receiving surface, a surface opposite to the light receiving surface, and an electrode wiring provided on the opposite surface;
A plurality of portions are connected to the electrode wiring, and there is a slack in the thickness direction between one connected portion and another connected portion adjacent to the one connected portion. A conductor wiring pattern;
A solar cell module provided with the sealing part which seals the said photovoltaic cell and the said conductor wiring pattern.   The solar cell module according to claim 1, wherein the sag is a sag that is convex or concave toward the solar cell side.   The sagging is 1.0% or more (however, at 25 ° C.) of the distance between the one connected part and the other connected part in the thickness direction of the solar battery cell. The solar cell module according to claim 2, which is slack.   The solar cell module according to claim 3, wherein the conductor wiring pattern includes copper or a copper alloy and has a thickness of 18 μm or more and 75 μm or less.   The solar cell module according to claim 4, wherein the copper or the copper alloy is a rolled foil having a 0.2% proof stress of 100 MPa or less.   The solar cell module according to claim 5, wherein the conductor wiring pattern has a ten-point average roughness and a surface roughness of 1.0 μm or less.   The solar cell module according to claim 6, wherein the conductor wiring pattern is a wiring pattern of a flexible wiring board. A cell preparation step of preparing solar cells having electrode wiring;
A wiring board preparation step of preparing a wiring board having a base material and a wiring pattern provided above the base material;
A mounting step of connecting the wiring pattern and the electrode wiring at a plurality of portions, and mounting the solar battery cell on the wiring board;
The base material is removed, the wiring pattern is exposed, the one connected part between the wiring pattern and the electrode wiring, and the other connected part adjacent to the one connected part And an exposing step of forming the wiring pattern having a sag in the thickness direction.   The said cell preparation process is a manufacturing method of the solar cell module of Claim 8 which prepares the said back contact type said photovoltaic cell which has a light-receiving surface in one surface, and has the said electrode wiring in the other surface.

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