JP3747096B2 - Solar cell module and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an amorphous solar cell module and a method for manufacturing the same, and more particularly to an electrode extraction configuration for an amorphous solar cell and a method for assembling the same.
[0002]
[Prior art]
Conventionally, a procedure for producing an amorphous solar cell module has been performed by the following method. First, a transparent conductive film, an amorphous semiconductor layer, and a back metal electrode are sequentially formed on an insulating glass substrate, and each time patterning is performed with a laser or the like, and integration is performed on a plurality of unit cells arranged in a line. It was. After that, lead wires such as copper foil are brought into contact with positive and negative electrode portions at both ends of the module, and these electrodes are further electrically connected to a solar cell terminal box (hereinafter referred to as a terminal box) using lead wires. Must be connected to.
[0003]
At this time, in order to lead the lead wire to the terminal box of the solar cell, since the terminal box is generally arranged on the center line of the module, the lead wire is put on the solar cell. When a short circuit occurs between unit cells (elements), battery characteristics are significantly deteriorated, and thus the following steps are required. FIG. 7 shows the process. First, on the solar cell module 101 (semiconductor layers and the like formed on the glass substrate 102 are not shown), lead wires 107 and 108 which are connected to positive and negative electrodes at both ends of the module and serve as electrodes are provided. The insulating film 110 is laid in correspondence with the position where the electrode lead-out part of the terminal box is arranged between the lead wires, and the two lead wires 111 and 112 having one ends connected to the lead wires 107 and 108, respectively, are connected to the insulating film 110. The electrodes are placed on top. Subsequently, an adhesive resin film 114 for closely attaching the cover film 115 placed thereon to the glass substrate 102 and the cover film 115 are stacked on the solar cell module 101 in this order. The cover film 115 is provided with an opening for taking out the electrode to the terminal box, and the lead wires 111 and 112 are passed through the opening to the opposite side of the glass substrate 102, that is, the cover film 115 on the back side of the solar cell. In the state derived | led-out above, it set to the vacuum heat-fusion apparatus (henceforth a vacuum laminator), and the sealing process was performed.
[0004]
By the way, the cover film 115 generally has a three-layer structure in order to suppress moisture permeation of water vapor, and has a structure in which a metal thin film is sandwiched inside. For this reason, in order to lead out the lead wires 111 and 112 to the back surface side of the solar cell of the cover film 115, it is necessary to devise a method for preventing the lead wires 111 and 112 from touching the end face of the opening of the cover film 115. . Therefore, a process for covering the periphery of the opening with an insulator 116 so that the lead wires 111 and 112 and the end face of the opening are not touched has been performed.
[0005]
[Problems to be solved by the invention]
However, in the configuration and manufacturing method of the conventional solar cell module as described above, the process from the completion of the unit cell to the vacuum lamination requires a lot of complicated work, and the problem in the process is the solar cell. Therefore, a very cautious work has been required, because there is a possibility that the characteristics deteriorated or the generated current may be conducted to the metal frame outside the solar cell.
The present invention has been made in order to solve the above-described problems, and provides a solar cell module and a method for manufacturing the same that are complicated and simplify many operations, improve yield, and reduce manufacturing costs. With the goal.
[0006]
[Means for Solving the Problems]
To accomplish the above object, on the insulation substrate, a transparent conductive film layer, an amorphous semiconductor layer, the backside metal layer are sequentially formed, a plurality of unit cells are integrated side by side in rows In the method for manufacturing a solar cell module in which the plurality of unit cells are covered with an adhesive layer and a cover film, the positive and negative electrodes located at both ends of the module are made of an insulating film different from the adhesive layer and the cover film. Attach one end of the coated lead wire, the other end of the adhesive layer and the lead wire with putting the cover film through a slit formed in the adhesive layer and the cover film, then, is melted and solidified the adhesive layer The insulating film has heat resistance capable of withstanding the temperature applied in the melting and solidifying step of the adhesive layer, and is a portion that passes through at least the slit of the lead wire. And it is characterized in that it is the entire surface of the coating.
[0007]
In the above-described configuration or method, since the lead wire led out from the positive and negative electrodes located at both ends of the module is one that is covered with a heat-resistant film that can withstand the heating temperature in the module sealing step, There is no need to lay an insulating film to prevent contact with the solar cell. Furthermore, in the sealing step of covering the solar cell with the cover film, the metal foil provided in the cover film may be short-circuited with the lead wire. Disappear. Therefore, the conventional trouble of providing an opening in the cover film and covering the periphery with an insulating material is not necessary, and it is only necessary to provide a slight lead-out slit on the cover film.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
1 is a sectional view of a solar cell module, FIG. 2 is a sectional view of a lead wire portion as an electrode provided at an end of the module, FIG. 3 is a plan view of the module, and FIG. 4 is a partially broken perspective view of the module. It is. In these drawings, an amorphous solar cell module 1 is formed by sequentially forming a transparent conductive film layer 3, an amorphous semiconductor layer 4, and a back metal layer 5 on a glass substrate 2, and a plurality of unit cells 6 are arranged in a row. Are integrated side by side. Sunlight enters from the glass substrate 2 side (lower side in FIG. 1). Lead wires 7 and 8 are led out from the positive and negative electrodes located at both ends of the unit cell 6 array of the module 1, and the lead wires 7 and 8 are fixed to the glass substrate 2 by the spare solder 9.
[0009]
In the solar cell module 1, for example, a transparent conductive film layer 3 is formed by a thermal CVD method on a glass substrate 2 having a substrate size of 800 mm × 400 mm and a thickness of 4 t, and a second harmonic of a YAG laser having a wavelength of 0.53 μm is used. The film was scribed from the film surface side and electrically separated into strips. Thereafter, ultrasonic cleaning is performed with pure water, and a mixed gas composed of monosilane, methane, and siborane at a substrate temperature of 200 ° C. and a reaction pressure of 0.5 to 1.0 Torr on the surface on which the transparent conductive film layer 3 is deposited, P-type, I-type and N-type amorphous semiconductor layers are obtained by decomposing a mixed gas comprising monosilane and hydrogen, and a mixed gas comprising monosilane, hydrogen and phosphine in this order in a capacitively coupled glow discharge decomposition apparatus. 4 (amorphous silicon or the like) is formed. Thereafter, the second harmonic of a YAG laser having a wavelength of 0.53 μm is incident from the glass surface side so as to be separated from the position slightly shifted from the scribe line by the laser so that the transparent conductive film layer 3 is not damaged. Subsequently, as the back surface metal layer 5, aluminum is formed by sputtering to a thickness of 300 nm, and this is opposite to the scribe line of the transparent conductive film layer 3 using the second harmonic of a YAG laser having a wavelength of 0.53 μm. Thus, a scribe line was inserted at a position slightly shifted from the scribe line of the amorphous semiconductor layer 4 and electrically separated to produce an integrated amorphous silicon solar cell.
[0010]
As the lead wires 7 and 8 which are positive and negative take-out electrodes provided at both ends of the solar cell, solder-plated copper foil is used, and adhesion to the glass substrate 2 is pre-soldered by an ultrasonic soldering method. The solder 9 is adhered to the glass substrate 2.
[0011]
The present invention is characterized by a method of routing a lead wire of a solar cell, particularly a method of connecting an electrode at both ends of the solar cell and a terminal box (not shown) arranged near the middle. Hereinafter, a configuration for leading electrodes from the lead wires 7 and 8 at both ends of the module 1 to a terminal box disposed near the middle of the module 1 and an assembly process thereof will be described with reference to FIGS. 5 and 6. FIG. 5 shows the lead 11 (12) used to derive the electrode, and FIG. 6 shows a series of steps for its assembly. The lead wire 11 (12) has a length longer than the distance necessary to lead out to the terminal box, and the central portion of the lead wire has a heating temperature and a heating time when the cover film is vacuum-laminated in a subsequent process. The structure is sandwiched between insulating films 13 having heat resistance characteristics that can withstand heat.
[0012]
The process of assembling the lead wires 7 and 8 and the lead wires 11 and 12 onto the glass substrate 2 will be described. First, the lead wires 7 and 8 are attached to both ends of the amorphous solar cell module 1 fabricated on the glass substrate 2. Next, one end of each of the lead wires 11 and 12 covered with the high heat-resistant film 13 is soldered to the lead wires 7 and 8. Subsequently, the solar cell is covered with an adhesive resin sheet (adhesive layer) 14 and a cover film 15. At this time, since the lead wires 11 and 12 are covered with the film 13, there is no possibility that the lead wires 11 and 12 and the metal foil contained in the cover film 15 are short-circuited. Accordingly, it is no longer necessary to provide an opening in the cover film 115 as in the prior art shown in FIG. 7 and cover the periphery with the insulator 116, and the lead wires 11 and 12 are slightly formed on the adhesive resin sheet 14 and the cover film 15. It is sufficient to provide a slit 16 for taking out. In this way, the lead wires 11 and 12 are led out to the back surface side of the solar cell of the cover film 15, and then the back surface of the solar cell is sealed by vacuum lamination.
[0013]
The lead wires 11 and 12 are preferably coated lead wires that are as thin as possible from the viewpoint of sealing the solar cell and have a thickness that is the same as or less than that of the adhesive layer. The cross-sectional shape of the lead wire itself may be a flat rectangular copper wire shape or a stranded wire shape copper wire. However, since the current of the solar cell flows through these lead wires, it is necessary to have an allowable current value greater than this current. Further, the film 13 covering the lead wires 11 and 12 needs to be made of a material that does not dissolve or deform even after the vacuum laminating process, and the characteristic particularly required here is the heat resistance of the film 13. Generally, since the curing temperature of the adhesive layer by the vacuum laminating method is around 150 ° C., it must be a resin that can withstand this temperature. Examples of the polymer material include heat-resistant polyester film, polyphenylene sulfide film, polyimide film, polyvinyl chloride film, polycarbonate, polyphenylene oxide, polysulfone, and polyether sulfone. Other examples include crepe paper. However, the film 13 is not limited to the above resin as long as the heat resistant temperature is equal to or higher than the sealing process temperature. These films 13 may be used to sandwich the lead wires 11 and 12, or in the case of a stranded wire, a copper wire may be covered with the resin.
[0014]
The dielectric breakdown voltage of the film 13 is desirably 1.5 KV or more as a value required from the solar cell power generation system. More preferably, the breakdown voltage may be 3 KV or more. In producing these lead wires 11 and 12, an adhesive is required particularly when a flat wire is used, but the properties required for the adhesive are high heat resistance and an electrical contact coefficient of 0.75 or more. More preferably, it is 0.90 or more.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Further, embodiments of the lead wires 11 and 12 will be described in detail with reference to FIGS. The lead wires 11 and 12 are 140 mm long and 5 mm wide solder-plated flat copper wire, leaving both ends at 3 mm and 20 mm respectively, and using a film 13 based on polyphenylene sulfide to connect the copper wire. I caught it. The film 13 has a width of 9 mm and a length of 117 mm. Moreover, the dielectric breakdown voltage of this film 13 is 5 KV, an adhesive is an acrylic adhesive, and an electrical contact coefficient is 1.0. Moreover, there was no change even if it passed through the process of the subsequent vacuum lamination for both a base material and an adhesive.
[0016]
The uncovered 3 mm long copper wire part of each one of the lead wires 11 and 12 is soldered to the lead wires 7 and 8 which are both positive and negative electrodes located at both ends of the glass substrate 2 of the solar cell. Thereafter, the adhesive resin sheet 14 with the slit 16 and the cover film 15 are placed on the electrode extraction portion of the terminal box, and the lead wires 11 and 12 are passed through the slit 16 portion and folded back onto the cover film. The sample thus prepared is set in a vacuum laminator, and the adhesive layer is melted and solidified. Here, the temperature of the vacuum laminating is 145 ° C. After about 30 minutes, it is removed from the vacuum laminator. With such a configuration, the lead wires 11 and 12 from the positive and negative electrodes 7 and 8 on both ends of the glass substrate 2 to the terminal box are only soldered, and the working time is greatly reduced compared to the conventional method. It can be shortened. In addition, the step of providing an opening in the cover film 115 required in the conventional process and protecting the periphery with the insulator 116 can be omitted. Then, an aluminum frame is attached to this sample, and a terminal box is attached. At this time, the solar cell module is completed by soldering the electrode in the terminal box and the 20 mm uncovered portion of the lead wires 11 and 12.
[0017]
【The invention's effect】
As described above, according to the present invention, in order to derive terminals from the positive and negative electrodes located at both ends of the solar cell module, the lead covered with the heat-resistant film that can withstand the heating temperature in the sealing process of the module surface. Since the wire is used, there is no possibility that the metal foil provided in the cover film is short-circuited with the lead wire in the laminate sealing step of covering the solar cell with the cover film. Therefore, many troublesome operations such as providing an opening in the cover film and covering the periphery with an insulator as in the prior art are not necessary. Therefore, the work process is simplified, and the situation where the characteristics of the solar cell are deteriorated or the generated current is not conducted to the metal frame outside the solar cell does not occur, so that the yield can be improved and the manufacturing cost can be reduced. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a solar cell module according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a lead wire portion as an electrode provided at an end of the module.
FIG. 3 is a plan view of the module.
FIG. 4 is a partially broken perspective view of the module.
FIG. 5 is a perspective view of a lead used to derive an electrode.
FIG. 6 is a perspective view showing a lead wire assembling step.
FIG. 7 is a perspective view showing a conventional lead wire assembling process.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Amorphous solar cell module 2 Glass substrate 3 Transparent conductive film layer 4 Amorphous semiconductor layer 5 Back surface metal layer 6 Unit cell 7, 8 Lead wire (electrode)
11, 12 Lead wire 13 Insulating film 14 Adhesive resin sheet (adhesive layer)
15 Cover film 16 Slit

Claims (1)

A transparent conductive film layer, an amorphous semiconductor layer, and a back metal layer are sequentially formed on an insulating substrate, and a plurality of unit cells are integrated in a line , and the plurality of unit cells are formed as an adhesive layer. In the method for manufacturing a solar cell module covered with a cover film ,
The positive and negative electrodes positioned at both ends of the module, the other end of the adhesive layer and connecting one end of a lead wire covered by different the dielectric film from the cover film, the adhesive layer and the lead wire together covered with the cover film Pass through the slit provided in the adhesive layer and the cover film , then melt and solidify the adhesive layer ,
The insulating film has heat resistance capable of withstanding the temperature applied in the melting and solidifying step of the adhesive layer, and covers at least the entire portion of the lead wire that passes through the slit . Production method.

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