JP3972252B2 - Solar cell module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solar cell module that is attached to the roof of a building and performs solar power generation, and more particularly to its internal wiring structure.
[0002]
[Prior art]
As a solar cell, there is a film substrate type thin film solar cell in which a flexible plastic sheet is used as a substrate, and a photoelectric conversion element, a transparent electrode, and a connection electrode made of an amorphous silicon (a-Si) thin film semiconductor layer are patterned on the substrate. It is publicly known (for example, refer to Patent Document 1).
[0003]
Next, the structure of the film substrate type thin film solar cell will be described with reference to FIG. In the figure, 1 is a plastic substrate, 2 is an amorphous silicon photoelectric conversion layer, 3 is a transparent electrode, 4 is a back electrode of the photoelectric conversion layer 2, and 5 is a connection electrode formed on the back surface of the plastic substrate 1 (the back surface of the thin film solar cell). (Side electrode), 6 is a current collecting hole (through hole) passing through the plastic substrate 1 and conducting between the transparent electrode 3 and the connection electrode 5, and 7 is a connection conducting between the connection electrode 5 and the back electrode 4. The transparent substrate 3 formed on the light incident side of the plastic substrate 1, the photoelectric conversion layer 2, and the back electrode 4 are divided into a plurality of unit cells by laser-scribing a cell dividing groove 8. The connecting electrode 5 formed on the back side of the thin film solar cell 10 in which a plurality of unit cells are connected in series is formed by laser scribing the dividing grooves 9 shifted by a half pitch from the unit cells. There.
[0004]
The above-mentioned film substrate type thin film solar cell is lightweight, and can be applied to various applications because of its roll-to-roll process and excellent mass productivity. In particular, in the field of electric power, a solar cell module in which a thin-film solar cell is provided with an exterior such as a sealing protective layer and a reinforcing plate so as to sufficiently withstand use in an outdoor environment has already been put into practical use. The light-receiving surface and back surface of the thin-film solar cell are sealed with a sheet-like protective layer, and further a metal reinforcing plate is lined, and then a terminal box is provided on the back side of the reinforcing plate, and the metal reinforcing plate communicates with the terminal box. In addition, the output lead wire is wired between the positive electrode and negative electrode of the thin film solar cell and the terminal box through the output lead wire drawing hole opened in the protective layer on the back side so that the output of the solar cell is taken out to the outside. A solar cell module is known (for example, see Patent Document 2).
Next, the assembly structure of the solar cell module disclosed in Patent Document 2 is shown in FIGS. The thin-film solar cell 10 has a film-like adhesive layer (EVA: ethylene-vinyl acetate copolymer) 11, a moisture-proof layer (ETFE) 12, a reinforced layer (EVA reinforced with glass fiber) 13, and a weather-resistant layer. Sealed with a light-receiving surface side protective layer 15 made of a surface protective layer (ETFE) 14, and the back side (non-light-receiving surface) is made of an adhesive layer (EVA) 16, an insulating layer (ETFE or polyimide) 17, and an adhesive layer 18. The back surface side protective layer 19 is sealed, and a reinforcing plate 20 made of a galvanized steel plate is lined on the back surface to give rigidity. In the process of manufacturing the solar cell module, the thin film solar cell is laminated with a protective layer and a reinforcing plate, and is heated and pressed by a vacuum laminator to thermally bond the layers to be integrated. .
[0005]
Further, in order to take out the power generation output of the solar cell, the thin film solar cell 10 is distributed in advance on both the left and right sides, and the internal lead wire (flat foil copper wire) 21 is laid in the non-power generation region, and then the conductive adhesive tape, flat foil The internal lead wire 21 and the back surface of the reinforcing plate 20 are connected to a positive electrode and a negative electrode connecting electrode 5 (see FIG. 9) formed on the back surface of the thin film solar cell 10 through a connecting wire 22 such as a copper wire. As shown in detail in FIG. 8, an output lead wire 24 is wired between the terminal box 23 and the terminal box 23, and the power generation output of the solar cell is taken out via the output cable 25 connected to the terminal box 23. Yes.
[0006]
That is, in FIG. 8, a hole 26 for leading out the output lead wire 24 is formed in the reinforcing plate 20 and the back surface side protective layer 19 continuously to the terminal box 23, and the tip of the output lead wire 24 inserted from the outside into this hole 26. Is soldered to the internal lead wire (flat foil copper wire) 21. 23a is a terminal block of the terminal box 23, 23b is a terminal screw, 23c is a cover of the terminal box, and after the output lead wire 23 is connected to the terminal block 23a of the terminal box 23, the inside of the box is filled with sealing resin. The rainwater is prevented from penetrating into the module from the outside.
[0007]
In addition, with respect to the output lead wire drawing structure described above, the inner peripheral surface of the hole opened in the reinforcing plate is sealed so as to prevent electrical leakage between the peripheral edge of the opening hole of the reinforcing plate and the output lead wire. A configuration of a solar cell module covered with a stopper (EVA) is also known (see, for example, Patent Document 3).
[0008]
[Patent Document 1]
JP 2000-223727 A (FIG. 6)
[Patent Document 2]
JP 2002-111032 A (FIGS. 5, 6, and 7)
[Patent Document 3]
JP 2001-44462 A (FIGS. 1 and 2)
[0009]
[Problems to be solved by the invention]
By the way, the above-described conventional solar cell module has the following problems in terms of production. That is,
(1) In the conventional configuration shown in FIGS. 6 to 8 (Patent Document 2), the hole 26 opened on the back side of the module for taking out the output of the solar cell is provided with a sealing protective material and a back reinforcing plate on the thin film solar cell. (A round hole or a square hole is opened in advance according to the installation position of the terminal box 23), and after laminating using a vacuum laminator, the back side protective layer 19 is removed from the opening hole of the reinforcing plate 20. The inner lead wire 21 is exposed at the bottom of the hole 26 by cutting, but it is necessary to pay close attention not to cut the inner lead wire of the conductive foil. Have difficulty.
[0010]
(2) In addition, as disclosed in Patent Document 3, a method of laminating on a thin film solar cell after opening a hole in a reinforcing plate and a sealing adhesive layer on the back side in advance, Since the melting level of the adhesive layer (EVA) changes depending on the pressure and heating conditions (pressing force, heating temperature, heating time) of the laminating process, it is reinforced with melted and flowed EVA without blocking the holes in actual work. It is difficult to cover the inner peripheral surface of the opening of the plate, and if the EVA melts and flows excessively, the hole that has been opened in advance may be blocked, and the wiring of the output lead wire performed thereafter may be hindered. is there.
[0011]
(3) Even if the above manufacturing problems can be cleared, the output lead wire inserted from the outside into the hole opening in the next step is exposed to the bottom inside the hole using a soldering tool. When soldered to the lead wire, the adhesive layer (EVA) facing the hole melts again under the influence of heating from the tool, and in the worst case, the internal lead wire and the metal reinforcing plate are in direct contact. There is a risk of electrical short circuit. Further, in the configuration of Patent Document 3, there is a risk that the EVA covering the opening hole of the reinforcing plate is melted by heating at the time of soldering and the output lead wire inserted into the hole comes into contact with the reinforcing plate and is electrically short-circuited. is there.
[0012]
(4) In the structure of FIGS. 6 to 8, the internal lead wire 21 laid in the non-power generation region of the thin film solar cell is omitted, and the output lead wire 24 is connected to the back side electrode surface of the thin film solar cell 10 (in FIG. 9). Although it is conceivable to improve the area efficiency of the power generation region by soldering directly to the connection electrode 9), in the experiment conducted by the inventors, the thin film solar cell itself is in the form of a film and the strength is extremely low. Practical reliability cannot be secured because the soldered part of the output lead wire is easily peeled off with a slight external force.
[0013]
The present invention has been made in view of the above points. The object of the present invention is to solve the above-mentioned problems and to provide an internal wiring structure for taking out the output of a thin-film solar cell. An object of the present invention is to provide a solar cell module that is improved so as to obtain the characteristics.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, the light-receiving surface and the back surface of a thin-film solar cell are sealed with a protective layer, and further a metal reinforcing plate is lined on the back surface-side protective layer, and then the reinforcing plate A terminal box is provided on the back side, and the output is taken out between the positive electrode and the negative electrode of the thin-film solar cell and the terminal box through the opening hole of the reinforcing plate and the hole opened in the protective layer on the back side. In solar cell modules with internal wiring,
Align the holes established the inverted U-shaped lead terminals on the back-side electrode surface of the thin-film solar cell, place the top end face of the inverted U-shaped lead terminals to face the opening hole of the reinforcing plate, the A lead wire is connected between the top end surface and the terminal block of the terminal box (Claim 1), and for this, a lead wire wired between the inverted U-shaped lead terminal and the terminal block of the terminal box is used. The terminal is soldered to the top end face of the terminal (claim 2). Furthermore, the reverse U-shaped lead terminal is formed by bending a copper foil adhesive tape obtained by applying a solder-tin plated bar-shaped copper foil or a copper foil with a conductive adhesive into an inverted U-shape. The outer end size is set smaller than the opening hole of the reinforcing plate with the top end face as the joint portion of the output lead wire (Claim 3).
[0015]
By the above configuration, the wiring work output leads performed after lamination of the module, the inverted U-shaped lead terminals with an opening hole that opens to the reinforcing plate on the back side which projects into the opening end surface of the open hole in a non-contact It may be electrically bonded to the top end surface of one end of the output lead (soldering), and since the reverse U-shaped lead terminals molded bent in an inverted U shape is self-supporting and maintains its shape, as in the prior art Compared to the wiring method in which the tip of the output lead wire is inserted into the opening hole of the reinforcing plate and the small diameter hole opened in the protective layer and joined to the electrode of the solar cell, the soldering tool can be handled easily and the wiring is automated Becomes easy. In addition, when soldering the inverted U-shaped lead terminal and the output lead wire, it is not necessary to insert a soldering tool into the hole, so that the influence of heat applied from the tool to the protective layer is small, which makes it possible to Thus, it is possible to effectively avoid electrical insulation defects caused by the melting of the adhesive layer (EVA) facing the hole.
[0016]
Moreover, even if the adhesive layer melts and closes the hole in the laminating process in which a protective layer and a reinforcing plate are laminated and integrated on the thin film solar cell, the reverse U-shaped lead terminal solder Since the joint surface protrudes from the end surface of the opening hole of the reinforcing plate and is exposed, there is no problem in the wiring work of the output lead wire performed thereafter.
[0017]
Further, according to the present invention, the opened holes in the protective layer to pass an inverted U-shaped lead terminals and said inverted U-shaped lead terminal in the configuration may be implemented in a manner as follows follow.
[0018]
(1) the trapezoid height of the inverted U-shaped lead terminals, and the opening hole end surface of the top end surface and the reinforcing plate of the inverted U-shaped lead terminal is set to be substantially aligned at the same height (claim 4) Make sure that the vacuum laminator does not interfere with the lead terminals.
[0019]
(2) The top end surface of the inverted U-shaped lead terminal is formed in an arch shape so that the arch-shaped end surface protrudes from the hole opening end surface of the reinforcing plate (Claim 5), and when processing with a vacuum laminator The top end surface of the inverted U-shaped lead terminal is pressed against the laminator side (the release sheet laid on the base of the laminator or the inner surface of the cover) in close contact, and the adhesive of the protective layer melted by the laminating process is applied to the top of the lead terminal Try to prevent sticking to the end face.
[0020]
(3) In order to ensure conductive bonding between the inverted U-shaped lead terminal and the electrode surface of the thin-film solar cell, both end legs of the inverted U-shaped lead terminal are superimposed on the back-side electrode surface of the thin-film solar cell. In addition, the both leg portions are conductively fixed to the electrode surface through a laminated tape made of conductive adhesive tape / metal tape / insulating tape.
[0021]
(4) In order to prevent the contact between the inverted U-shaped lead terminal and the metal reinforcing plate and improve the electrical insulation reliability, reverse the flame resistance and non-flammability of the solar cell module. A nonflammable glass nonwoven fabric is filled in a gap between the U-shaped lead terminal and the opening hole of the reinforcing plate and the hole opened in the back surface side protective layer (Claim 7 ).
[0022]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on the examples shown in FIGS. In addition, in the figure of an Example, the same code | symbol is attached | subjected to the member corresponding to FIGS. 6-8, and the description is abbreviate | omitted.
[0023]
[Example 1]
First, an internal wiring structure of a solar cell module and an exploded view thereof according to an embodiment of the present invention are shown in FIGS. That is, the solar cell module of the illustrated embodiment is basically the same as the conventional structure described with reference to FIGS. 6 and 7, but instead of the flat lead internal lead wire 21 in the conventional structure, the illustrated embodiment is a thin film solar cell. 10 backside electrode 10a (the connection electrode 5 in FIG. 9 + pole, - corresponding to the pole) of installing an inverted U-shaped lead terminal 27 molded into an inverted U-shape, of the inverted U-shaped lead terminal 27 The top end face (lower end face in the figure) is pulled out to the end face of the opening hole 20a formed in the reinforcing plate 20 lined on the module as described later, and then soldered to the top end face of the inverted U-shaped lead terminal 27. The lead wire 28 is connected to the terminal block 23 a of the terminal box 23.
[0024]
That is, a lead plate opening hole ( diameter 10 mm ) 20a is opened in the reinforcing plate 20 (0.8 mm thick steel plate) lined on the module in accordance with the position of the output lead wiring, and the opening hole 20a is further opened. A hole 26 is cut and formed in the back surface side protective layer 19 in alignment.
[0025]
On the other hand, the reverse U-shaped lead terminal 27 is a bar-shaped copper foil (width 5 mm, thickness 0.1 mm) plated with solder or tin, or a copper foil obtained by applying a conductive adhesive to the copper foil. adhesive tape in FIGS. 3 (a) formed by bending and formed in an inverted U-shape as a small size than the opening hole 20a of the reinforcing plate 20 mentioned above the end face 27a of the top as the soldering surface of the output lead 28 And both end legs 27b are placed on the back surface side electrode 10a of the thin-film solar cell 10 and the conductive adhesive tape 29a / metal tape (aluminum foil) as shown in FIGS. 4 (a) and 4 (b). ) A three-layer laminated tape (width 8 mm) 29 made of 29b / insulating tape 29c is attached and fixed to the electrode surface. Also, the height H of the inverted U-shaped lead terminal 27 is such that the top end face 27a is aligned with the end face of the opening hole 20a of the reinforcing plate 20 and faces the center of the opening hole 20a in the module assembly state shown in FIG. Set to.
[0026]
The module assembly having the above configuration is performed in the following procedure. That is, in the thin film solar cell 10, the inverted U-shaped lead terminal 27 is installed in advance at the positive electrode and negative electrode positions of the back surface side electrode 10a. In the subsequent module assembling step, the thin-film solar cell 10 with the inverted U-shaped lead terminal 27 and the back surface side protective layer 19 in which the holes 26 are formed are stacked on the light receiving surface side protective layer 15 in this order, and then the reinforcing plate 20 is attached. assemble. In this process, the end surface of the inverted U-shaped lead terminal 27 passes through the hole 26 of the back surface side protective layer 19 and is drawn out to the end surface of the opening hole 20a of the reinforcing plate 20 to form a temporary assembly.
[0027]
Next, the release sheet is overlaid on this temporary assembly and set in a vacuum laminator. The inside of the laminator is deaerated to pressurize the module assembly from above and below, under predetermined heat treatment conditions (heating temperature 150 ° C., heating time 20 Laminate together in minutes). In this laminating process, since the top end surface 27a of the inverted U-shaped lead terminal 27 does not protrude outward from the opening hole 20a of the reinforcing plate 20, the inverted U-shaped lead terminal 27 and the inverted U-shaped lead terminal 27 There is no interference.
[0028]
In this case, as shown in FIG. 3 (b), the top end surface 27a of the inverted U-shaped lead terminal 27 is formed in an arch shape in advance, and the arched top end surface 27a is reinforced in a temporarily assembled state of the module. If it protrudes slightly from the opening hole 20a of the plate 20, when the module temporary assembly is set on a vacuum laminator and a pressure is applied, the arch-shaped top end face 27a is deformed so as to be crushed. It comes in close contact with the release sheet placed under the module. This prevents EVA from adhering to the end face of the inverted U-shaped lead terminal 27 even if the adhesive layer (EVA) 18 (see FIG. 2) of the back surface side protective layer 19 is melted by the heating of the laminating process. A solder joint surface can be secured. Alternatively, a fluororesin adhesive tape may be applied in advance to the top end surface 27a of the inverted U-shaped lead terminal 27 to protect the solder joint surface.
[0029]
Next, after attaching the case of the terminal box 23 to the opening hole 20a of the reinforcing plate 20 to the laminated module, it is exposed to the end face of the opening hole 20a of the reinforcing plate 20 by an automatic soldering device (pulse heat type). The output lead wire 28 is soldered to the top end surface 27a of the inverted U-shaped lead terminal 27 (a solder joint 30 is shown in FIG. 1). The output lead 28 is suitably a copper foil that is 0.035 to 0.2 mm in thickness and 3 mm in width subjected to solder / tin plating in consideration of handling by an automatic soldering apparatus and solder joint strength.
[0030]
After one end of the output lead wire 28 is soldered to the inverted U-shaped lead terminal 27, the other end of the lead wire is connected to the terminal block 23a of the terminal box 23 (soldering or screw fastening). The case is filled with silicone resin, and the solder joint 30 between the inverted U-shaped lead terminal 27 and the output lead wire 28 and the opening hole 20a of the reinforcing plate 20 are sealed to prevent moisture from entering. Finally, the terminal box 23 is covered and the assembly of the solar cell module is completed.
[0031]
[Example 2]
Next, an embodiment corresponding to claim 8 of the present invention will be described with reference to FIG. That is, a product of a solar cell module installed on the roof of a wooden house is required to have a flame-retardant structure for preventing fire spread. From this point of view, the solar cell module is lined with a reinforcing plate 20 made of a steel plate. The flame retardancy is increased. However, in the structure in which the opening hole 20a is opened in the reinforcing plate 20 and the terminal box 23 is attached in order to take out the solar cell output, the opening portion of the opening hole 20a becomes a weak point of fire spread.
[0032]
Therefore, in this embodiment, the non-flammable glass nonwoven fabric 31 is provided in the gap between the opening hole 20a of the reinforcing plate 20 and the inverted U-shaped lead terminal 27 protruding into the opening hole 20a in the temporarily assembled state of the module. Filled.
[0033]
According to this structure, the glass nonwoven fabric 31 prevents fire spread through the opening 20a of the reinforcing plate 20, and also electrically contacts the inverted U-shaped lead terminal 27 and the opening hole 20a of the reinforcing plate 20. The reliability of the solar cell module is improved by serving as an insulating material to prevent.
[0034]
【The invention's effect】
As described above, according to the present invention, the light-receiving surface and the back surface of the thin-film solar cell are sealed with a protective layer, and further, a metal reinforcing plate is lined on the back surface-side protective layer, and then the back surface of the reinforcing plate. A terminal box was provided, and internal wiring was provided between the positive electrode and negative electrode of the thin-film solar cell and the terminal box through the opening hole of the reinforcing plate and the hole opened in the back side protective layer in communication with the terminal box. in the solar cell module, and align the holes established the inverted U-shaped lead terminals on the back-side electrode surface of the thin-film solar cell, it is made to face the top end surface of the inverted U-shaped lead terminals to the opening hole of the reinforcing plate By arranging the output lead wire between the top end surface and the terminal block of the terminal box,
Compared to the conventional internal wiring structure in which the lead wires are wired after the module is laminated, and the lead wire is inserted into the opening hole of the metal reinforcing plate and soldered at the bottom of the opening hole. The wiring can be automated easily. In addition, when soldering the inverted U-shaped lead terminal and the output lead wire, it is not necessary to insert a soldering tool into the opening hole, so the influence of heat applied from the tool to the protective layer is small. Thus, it is possible to effectively avoid electrical insulation defects caused by melting of the adhesive layer (EVA) facing the opening hole. Moreover, even if the adhesive layer melts and closes the opening hole in the laminating process in which the protective layer and the reinforcing plate are laminated and integrated with the thin film solar cell, the opening of the inverted U-shaped lead terminal is blocked. In addition to the convenience of the lead wiring work, the solder joint surface is exposed through the end face of the opening hole of the reinforcing plate, so there will be no hindrance to the subsequent wiring work of the output lead wire. A solar cell module with high electrical and mechanical reliability can be provided.
[0035]
Moreover, according to the structure of Claim 7 which filled the nonflammable glass nonwoven fabric between the opening hole of the reinforcing plate and the inverted U-shaped lead terminal, the solar cell module is installed on the roof of a wooden house or the like. This is effective in ensuring electrical insulation as well as preventing fire spread.
[Brief description of the drawings]
[1] of the inverted U-shaped lead terminals in exploded view FIG. 3 FIG. 1 of the thin-film solar cell module in a cross-section view FIG. 1; FIG representing the internal wiring structure of a solar cell module according to Example 1 of the present invention (A), (b) is an external perspective view of different embodiments. FIG. 4 is an attachment structure diagram of an inverted U-shaped lead terminal installed on the back side electrode of the thin film solar cell in FIG. a) is a back view thereof, and (b) is a cross-sectional view of a laminated tape for fixing lead terminals. FIG. 5 is a cross-sectional view showing an internal wiring structure of a solar cell module according to Embodiment 2 of the present invention. FIG. 7 is a cross-sectional view taken along the line XX in FIG. 6. FIG. 8 is an enlarged cross-sectional view of the terminal box portion in FIG. 7. FIG. 9 is a structural explanatory view of the thin-film solar cell.
DESCRIPTION OF SYMBOLS 10 Thin film solar cell 15 Light-receiving surface side protective layer 19 Back surface side protective layer 20 Reinforcing plate 20a Opening hole 23 Terminal box 23a Terminal block 26 Hole 27 Reverse U-shaped lead terminal 27a Top end surface 27b Both end legs 28 Output lead wire 29 Laminated tape 29a Conductive adhesive tape 29b Metal tape 29c Insulating tape 30 Solder joint 31 Glass nonwoven fabric

Claims (7)

The light-receiving surface and back surface of the thin-film solar cell are sealed with a protective layer, and further, a metal reinforcing plate is lined on the back surface-side protective layer, and then a terminal box is provided on the back surface of the reinforcing plate, and communicated with the terminal box. In the solar cell module in which the internal wiring is provided between the positive electrode of the thin film solar cell, the positive electrode, and the terminal box through the opening hole of the reinforcing plate and the hole opened in the back surface side protective layer,
Align the holes established the inverted U-shaped lead terminals on the back-side electrode surface of the thin-film solar cell, place the top end face of the inverted U-shaped lead terminals to face the opening hole of the reinforcing plate, the An output lead wire is wired between the top end face and the terminal block of the terminal box. 2. The solar cell module according to claim 1, wherein an output lead wire wired between the inverted U-shaped lead terminal and the terminal block of the terminal box is soldered to the top end face of the lead terminal. It will be formed by bending a copper foil adhesive tape which inverted U-shaped lead terminal is coated with a conductive adhesive composition into bars of copper foil or copper foil which has been subjected to solder-tinned inverted U-shape, the top end surface The solar cell module according to claim 1 or 2, wherein an outer size of the output lead wire is set smaller than an opening hole of the reinforcing plate. The height of the inverted U-shaped lead terminal, any one of the top end face of the inverted U-shaped lead terminals claims 1, characterized in that configured to match substantially the opening hole end surface of the reinforcing plate 3 1 The solar cell module according to item. 5. The solar cell module according to claim 4, wherein the top end surface of the inverted U-shaped lead terminal is formed in an arch shape , and the arch-shaped end surface protrudes from the end surface of the opening hole of the reinforcing plate. The opposite leg portions of the inverted U-shaped lead terminal are superimposed on the back side electrode surface of the thin film solar cell, and the both end leg portions are electrically connected to the electrode surface via a laminated tape made of conductive adhesive tape / metal tape / insulating tape. The solar cell module according to claim 1, wherein the solar cell module is fixed to the solar cell module. Any one of claims 1 to 6, characterized in that the gap between the open hole in the opening hole and the back surface side protective layer of the inverted U-shaped lead terminals and the reinforcing plate were filled with incombustible glass nonwoven The solar cell module according to.

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