JP5656680B2 - Manufacturing method of solar cell module - Google Patents

Description

  The present invention relates to a method for manufacturing a solar cell module in which a solar cell element is sandwiched and integrated between two glass plates or the like.

  In Patent Document 1, since internal stress such as tensile stress and compressive stress exists in the non-consolidated semiconductor film (light absorption layer), if this non-consolidated semiconductor film is formed on a stainless steel substrate, the internal stress is reduced. Caused warpage occurs. In order to correct this warpage, the substrate is forcibly bent in the opposite direction to the warp in advance, so that the restoring force of the substrate is almost balanced with the internal stress of the semiconductor film, so that the remaining in the semiconductor film of the completed solar cell element. The content which reduces the compressive stress to perform is disclosed.

JP-A-62-101080

A recent solar cell module employs a structure in which a battery element is sandwiched between transparent plate members such as two glass plates in order to increase mechanical strength and weather resistance.
Specifically, a cover glass having the same dimensions is stacked on a glass substrate having a solar cell element formed on the surface, and a filler such as EVA (ethylene vinyl acetate copolymer) is placed between the glass substrate and the cover glass. The periphery of the glass substrate and the cover glass is sealed with a sealing material.

Further, as a solar cell having high photoelectric conversion efficiency, a Cu—In—Ga—Se solar cell is known, and high temperature treatment (selenization treatment) is required to increase the photoelectric efficiency. For this reason, compared with the conventional blue plate glass, white plate glass with less iron content and excellent heat resistance is used as the substrate glass.

On the other hand, as a cover glass, since it is advantageous in terms of cost, blue plate glass is used as usual. However, the white plate glass has an expansion coefficient (E) of 38.0 × 10 ⁻⁷ / K and the blue plate glass has an expansion coefficient (E) of 90.3 × 10 ⁻⁷ / K. There is a disadvantage that the solar cell is warped.

Patent Document 1 described above also corrects the warpage of the solar cell, but the content disclosed in Patent Document 1 corrects the warping of the module due to the compressive stress inherent in the semiconductor film. It cannot be applied as it is to the warp due to the difference in expansion coefficient between the two members sandwiching the element.

  The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a method for controlling the degree of bending of a solar cell module during manufacturing, including flatness.

In order to solve the above problems, a method for manufacturing a solar cell module according to the present invention includes the following steps.
Forming a solar cell element on the surface of the substrate;
A step of superposing a resin sheet that is crosslinked by heating on the surface of the substrate on which the solar cell elements are formed, and further superposing a transparent cover member thereon.
A step of deaerating and heating the substrate, the resin sheet, and the transparent cover member in a stacked state to bring the resin sheet into a semi-crosslinked state and temporarily bonding the substrate and the transparent cover member.
The step of returning the temporarily bonded laminate to room temperature and subjecting the laminate to straight bending in this state.
A step of heating the straightened bent laminate to completely crosslink the semi-crosslinked resin.

In the above method for manufacturing a solar cell module, the half-crosslinked state refers to, for example, a crosslinking rate of 50% or less. Further, when producing a flat solar cell module without bending as a product, the direction of straightening bending is opposite to the warp of the temporarily bonded laminate, and the amount of straightening bending is the amount of the laminate of the temporarily bonded state. The amount of warpage may be canceled, but a solar cell module having an arbitrary curvature can be manufactured by changing the direction and amount of straightening bending.

According to the present invention, the warp due to the material and structure of the thin film solar cell module can be corrected without significantly changing the conventional process.
Moreover, according to the method of the present invention, not only a flat solar cell module can be manufactured, but also a solar cell module having a desired curved surface can be manufactured, and it has excellent design properties, and can be applied to, for example, a roof of a vehicle body.

The figure explaining the manufacturing method of the solar cell module which concerns on this invention in process order The figure which shows the state which is carrying out the correction | amendment curve of the solar cell module before curing Graph showing the relationship between the amount of correction and the amount of warpage after correction

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, in the present invention, the substrate 1, the transparent cover member 2, and the resin sheet 3 are aligned so as to have a predetermined arrangement. In FIG. 1, the substrate 1 is illustrated below and the transparent cover member 2 is illustrated above, but either may be used.

  As the substrate 1, white plate glass having excellent heat resistance is used, and as the transparent cover member 2, blue plate glass is used. A solar cell element 4 is formed on one side of the substrate 1 in advance. The resin sheet 3 is sandwiched between the surface on which the solar cell element 4 is formed and the transparent cover member 2. The resin sheet 3 uses a material that crosslinks by heating, for example, EVA (ethylene vinyl acetate copolymer).

  The substrate 1 and the transparent cover member 2 are arranged at predetermined positions with the resin sheet 3 interposed therebetween to form a laminate, which is put into a laminating apparatus (not shown) and deaerated and heated (about 130 ° C.). I do. The laminating apparatus includes a horizontal mounting table on which the stacked body is mounted, and the stacked body is heated while being pressed from above while being mounted on the mounting table. The resin sheet 3 is once liquefied by heating, and then a resin crosslinking reaction starts and hardens. In this laminating process, the laminate is taken out from the laminating apparatus at the time before the cross-linking reaction is completed (semi-cross-linked state). That is, when the laminate is temporarily bonded to the substrate 1 and the transparent cover member 2, that is, when the laminate is taken out from the laminating apparatus, the resin of the resin sheet 3 is not completely cured, and the substrate 1 and the cover member are temporarily It is a state of adhesion.

  When the temporarily bonded laminated body taken out from the laminating apparatus is cooled to room temperature (25 ° C.), warpage occurs due to a difference in thermal expansion coefficient between the substrate 1 and the transparent cover member 2.

  In the present invention, the laminated body in which the warpage has occurred is subjected to a correction curve process using the jig 5. The jig 5 has a rod-like shape, but other three-dimensional jigs may be used. As will be described later, the jig 5 is intended to control the shape of the solar cell module after the resin is cross-linked by correcting or utilizing the warping. A dimensionally shaped solar cell module can be manufactured.

  After that, it is put into a heating device such as an oven and cured (about 130 ° C.) to completely crosslink the resin in a semi-crosslinked state. The curing time is longer than the heating time in the laminating apparatus.

  After the resin is completely cross-linked, it is removed from the heating device and cooled. Due to this cooling, the laminate is likely to warp due to the difference in thermal expansion coefficient (difference in thermal shrinkage) between the substrate 1 and the transparent cover member 2, but the laminate is preliminarily curved in a direction opposite to the warp, and Since the amount of bending is an amount for canceling the warp generated when taken out from the laminating apparatus, the solar cell module after cooling has a flat plate shape without bending.

  After that, the solar cell module is completed by sealing the periphery of the laminate composed of the substrate 1 and the transparent cover member 2 with a sealing material such as butyl rubber. The sealing with the peripheral sealing material may be performed by placing a sealing material on the peripheral edge of the substrate 1 before the laminating process.

  FIG. 3 shows a comparison between the correction amount and the amount of warpage after correction. For example, when a 10 mm laminated body is straight-curved in a direction opposite to the warpage after lamination, the amount of warpage after correction becomes almost zero.

In the present invention, a solar cell module having a desired shape can be manufactured by adding a straightening and curving step as it is without greatly changing the manufacturing process of a conventional thin film solar cell module.

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Transparent cover member, 3 ... Resin sheet, 4 ... Solar cell element, 5 ... Correction jig | tool.

Claims (3)

The step of forming a solar cell element on the surface of the substrate The step of superposing a resin sheet that is crosslinked by heating on the surface of the substrate on which the solar cell element is formed, and further laminating a transparent cover member thereon The substrate, resin sheet, and transparent cover member Degassing and heating in a stacked state to make the resin sheet semi-crosslinked, temporarily bonding the substrate and the transparent cover member, returning the temporarily bonded laminate to room temperature, and correcting to the laminate in this state Bending step A method for producing a solar cell module comprising the step of heating the straight-bending laminate to completely cross-link the semi-crosslinked resin. The method for manufacturing a solar cell module according to claim 1, wherein the half-crosslinked state has a crosslinking rate of 50% or less. 2. The method of manufacturing a solar cell module according to claim 1, wherein the direction of the straightening bending is opposite to the warping of the temporarily bonded laminated body, and the amount of the straightening bending is the warping of the temporarily bonded laminated body. A method for manufacturing a solar cell module, wherein the amount is canceled.

Images