JP4974301B2 - Manufacturing method of solar cell module - Google Patents

Description

  The present invention relates to a technique for attaching a ribbon wire for taking out electric power generated in a solar cell submodule to an electrode formed on the solar cell submodule.

  2. Description of the Related Art Conventionally, an integrated thin film solar cell module is configured by laminating a transparent conductive film, a photoelectric conversion layer in which a p layer and an n layer made of a thin film semiconductor, and the like are sequentially laminated on an insulating substrate such as glass. Is done. And this laminated body is connected in series, parallel, or series-parallel, and an integrated type thin film solar cell module is comprised.

The electric power generated in this module is output to the outside through a conductor such as a bus bar or a ribbon wire attached to the electrode formed on the laminate.
Here, the conductor is conventionally attached so as to adhere to the entire electrode by soldering. In this way, the reason why the conductor is adhered to the entire electrode by soldering is to output the power generated in the module without losing power, but the cost is required to solder the conductor to the entire electrode. In addition, the thickness of the module is increased and the number of manufacturing processes is excessive. Moreover, since it was necessary to thicken the back electrode layer in order to prevent the electrical connection between the back electrode layer and the conductor from becoming unstable due to solder corrosion, this also increased the cost.

In view of this point, a light transmissive insulating substrate, a laminated structure including a transparent conductive film, a photoelectric conversion layer, and a back electrode layer provided on the light transmissive insulating substrate, and a back electrode layer of the laminated structure A thin-film solar cell comprising: a bus bar provided on the back electrode layer; and the bus bar is coupled to the back electrode layer via a conductive paste applied on the back electrode layer at a constant pitch. It has been proposed (see Patent Document 1).
Further, a solar cell module configured by using a submodule in which a power generation element including an n-type semiconductor layer and a p-type semiconductor layer is formed on a light-transmitting substrate, the output terminal of the solar cell module and the A solar cell module is proposed in which a lead wire that electrically connects an electrode terminal of a submodule is attached to the electrode terminal of the submodule with a conductive paste, and a mounting portion of the lead wire is covered with a coating agent (See Patent Document 2).

JP 2002-314104 A JP 2001-210850 A

The technique described in Patent Document 1 can prevent solder corrosion of the back electrode layer and minimize the thickness of the back electrode layer by interposing a conductive paste in the connection between the conductor and the electrode. In addition, the manufacturing cost is reduced.
However, in the technique described in Patent Document 1, since the bus bar and the back electrode layer are simply bonded by the conductive paste applied at a constant pitch, the bus bar and the back electrode layer are bonded by the conductive paste. Where there is no electrical connection, the electrical connection is unstable.
Also, when the bus bar is attached to the electrode, the solder bar is heated with a pulse heater or the like and bonded with the molten solder. Therefore, even if a conductive paste is interposed, solder corrosion does not occur. It will occur to some extent. Furthermore, a process for attaching the bus bar to the electrode is required separately, and it cannot be said that the manufacturing cost is reduced.

In addition, the technique described in Patent Document 2 uses a conductive paste to attach lead wires to the electrode terminals of the solar cell submodule, and further cover the attachment portion with a coating agent, thereby suppressing output loss. The stability of the connection between the electrode terminal and the lead wire is improved.
However, in the technique described in Patent Document 2, only one end of the lead wire is attached to the electrode, and the technique is applied in the case where the entire electrode formed in a strip shape is attached to the solar cell submodule. If the lead wire is attached by applying the conductive paste to the whole, the manufacturing cost is high and the lead wire is disconnected due to the difference in the linear expansion coefficient between the lead wire and the substrate on which the electrode is formed. There is a fear. Further, since the coating agent is used only for securing the mounting strength of the lead wire, the manufacturing cost is further increased, and the manufacturing process is increased and the process management is troublesome.

  Therefore, an object of the present invention is to provide a solar cell module that reliably attaches a ribbon wire to an electrode without using solder and reduces the manufacturing process and manufacturing cost, and a manufacturing method thereof.

In order to achieve the above object, a method for manufacturing a solar cell module according to the present invention includes a solar cell device in which a solar cell device is formed and a band-shaped electrode for taking out electric power generated in the solar cell device is formed. A module, a ribbon wire attached to the electrode, a cover glass attached to the solar cell submodule so as to cover the electrode, and a space between the solar cell submodule and the cover glass, and the solar cell a manufacturing method of a solar cell module having a filler for bonding holds the submodule and a cover glass, and a step of intermittently applying the conductive paste on the electrode, the conductive paste is applied on the electrode, to install the ribbon wire remembering slack portion where the conductive paste does not adhere A step, on the ribbon wire, a step of laminating the filler and a cover glass, and the solar cell submodule ribbon wire is placed on the electrode, and the filler, and the cover glass, heated By laminating by compression, the filler is bonded between the solar cell submodule and the cover glass, and at the same time, the filler is bonded and held between the solar cell submodule and the cover glass. and the ribbon wire, including the part where the conductive paste of the ribbon wire has not been applied, and having a a install them step by direct contact with surface electrode of the solar cell submodule.

  The solar cell device may be a CIS thin film solar cell device.

  Further, the ribbon wire may be attached to the electrode by being adhered with a conductive paste applied at a constant interval of 0.5 cm to 7 cm.

  The conductive paste may be one in which silver fine particles are used as the conductive filler.

  The conductive paste may be cured at a heating temperature at the time of a laminating process in which the solar cell submodule and the cover glass are bonded and held via the filler.

According to the present invention, since the ribbon wire is attached to the electrode formed on the solar cell submodule by the conductive paste without using solder, there is no fear of solder corrosion.
In addition, by laminating the solar cell submodule, the filler, and the cover glass, the ribbon wire is sandwiched between the solar cell submodule and the cover glass so that the conductive paste is not applied. Since the ribbon wire including the portion is attached in surface contact with the electrode, a stable electrical connection is ensured.
Furthermore, since the ribbon wire is bonded to the electrode at the same time in one step of laminating each member as described above, the manufacturing process can be reduced and the manufacturing cost can be reduced.

Next, a solar cell module according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the solar cell module according to the present embodiment has a structure composed of a solar cell sub-module 1, a ribbon wire 2, a filler 3, and a cover glass 4, and includes a ribbon wire. 2 is adhered to the solar cell submodule 1 by a conductive paste 5.

As shown in FIG. 3, the solar cell submodule 1 is formed by forming a solar cell device 11 that receives sunlight and generates power on a glass substrate 10 such as blue plate glass.
The solar cell device 11 is a so-called CIS-based thin-film solar cell device, and includes a back electrode layer 1A made of a metal such as molybdenum (Mo), a p-type CIS-based light absorption layer 1B, a high-resistance buffer layer 1C, and an n-type. It consists of a substrate structure in which window layers (transparent conductive films) 1D are sequentially laminated, and this solar cell device 11 generates electricity by receiving light such as sunlight.

Here, the p-type CIS-based light absorption layer 1B is a thin film having a thickness of 1 to 3 μm having a p-type conductivity I-III-VI group ₂ chalcopyrite structure. For example, CuInSe ₂ , Cu (InGa) A multi-component compound semiconductor thin film such as Se ₂ or Cu (InGa) (SSe) ₂ . The p-type CIS light absorption layer 1B includes, in addition, a selenide CIS light absorption layer, a sulfide CIS light absorption layer, and a selenide / sulfide CIS light absorption layer. The system light absorption layer is made of CuInSe ₂ , Cu (InGa) Se ₂ or CuGaSe ₂ , and the sulfide-based CIS system light absorption layer is made of CuInS ₂ , Cu (InGa) S ₂ , CuGaS ₂ , and the selenization. The sulfide-based CIS-based light absorption layer is CuIn (SSe) ₂ , Cu (InGa) (SSe) ₂ , CuGa (SSe) ₂ , or CuIn (SSe) ₂ as the surface layer. CuInSe _2, CuIn Cu with (SSe) ₂ of the _{Cu (InGa) Se 2, CuIn} (SSe) 2 having as a surface layer as a surface layer _{(InGa) (SSe) 2,} C with a CuGaSe ₂ having In the (SSe) ₂ as a _{CuGaSe 2, Cu (InGa) (} SSe) Cu with ₂ as a surface layer _{(InGa) Se 2, Cu (} InGa) (SSe) 2 the surface layer having a surface layer, CuGa (SSe) is CuGaSe ₂ with ₂ Cu (InGa) Se ₂ or CuGa (SSe) ₂ as a surface layer with a surface layer.
The p-type CIS light absorption layer 1B is formed by a selenization / sulfurization method or a multi-source co-evaporation method.

The solar cell device 11 is subjected to predetermined patterning for securing electrical connection by a mechanical scribing device, a laser scribing device, or the like, and p-type CIS light laminated on the back electrode layer 1A. The back electrode layer 1A with the end portions of the absorption layer 1B, the high-resistance buffer layer 1C, and the n-type window layer 1D exposed in a band shape is used as an electrode S so that power generated by light reception can be output. It has become.
The electrodes S provided at two places constitute a pair of positive and negative electrodes, and the method of forming the electrodes S is not limited to a scribing apparatus, and may be chemical etching or the like, and is not particularly limited.

The ribbon wire 2 is attached to the electrode S and derives the electric power generated in the solar cell submodule 1 to the outside. The ribbon wire 2 can be constituted by a strip-shaped metal thin plate having a thickness of about 80 to 150 μm and a width of about 1.5 to 2.0 mm made of, for example, aluminum, silver, copper, or tin-plated copper.
The ribbon wire 2 is adhered to the electrode S formed on the solar cell submodule 1 with the conductive paste 5 applied intermittently on the electrode S, and the solar cell sub via the filler 3. It is sandwiched between the module 1 and the cover glass 4 so as to be in pressure contact with the electrode S, and is in surface contact with the electrode S including a portion not adhered to the electrode S by the conductive paste.

The filler 3 melts and spreads by pressing while being heated while sandwiched between the solar cell submodule 1 and the cover glass 4, fills the gap, and bonds the solar cell submodule 1 and the cover glass 4 together. To do.
As the material of the filler 3, for example, sheet-like EVA (ethylene vinyl acetate copolymer) can be used.

  The cover glass 4 is glass that is attached to the solar cell submodule 1 so as to cover the solar cell device 11. The cover glass 4 can be composed of tempered glass or the like, thereby protecting the solar cell device 11.

The conductive paste 5 is a mixture of a polymer solution and a conductive filler, and bonds the electrode S and the ribbon wire 2 while ensuring conductivity.
In this embodiment, the conductive paste 5 uses silver (Ag) fine particles as a conductive filler. In addition, fine particles made of copper (Cu), molybdenum (Mo), carbon (C), or the like are used. It can also be used.

Further, in the present embodiment, the conductive paste 5 is a polymer type that cures at a relatively low temperature, in particular, a heating temperature of 150 ° C. to 200 ° C. and a heating time necessary for crosslinking EVA used as the filler 3. Those that cure under conditions of about 30 minutes are preferably used. Thus, by setting the conditions for crosslinking of the filler 3 and curing of the conductive paste 5 within the same range, the crosslinking of the filler 3 and curing of the conductive paste 5 can be performed simultaneously by the same process. .
Furthermore, the polymer type is preferable because the resistance value is lowered by the fusion of the silver oxide produced by the fusion during the reduction of the silver oxide or the thermal decomposition of the organometallic compound in the contact between the conductive fillers by heating.

  Specific examples of the conductive paste 5 that can be used include CE-3920 (manufactured by Emerson & Cumming), FA-705BN, XA-874 (manufactured by Fujikura Kasei Co., Ltd.), ECM-100 AA2020, ECM. -100 AA2021 (manufactured by Taiyo Ink Manufacturing Co., Ltd.), Sylbest (P-2501LA) (manufactured by Tokuru Chemical Laboratory Co., Ltd.).

  In the manufacturing process of the solar cell module according to the present embodiment, this conductive paste 5 is intermittently applied on the electrode S of the solar cell submodule 1 with a dispenser or the like, and the ribbon wire 2 is placed thereon. Further, when the filler 3 and the cover glass 4 are sequentially laminated thereon and laminated, the conductive paste 5 is cured by heating during the lamination, and the electrode S and the ribbon wire 2 are bonded. .

When the conductive paste 5 is applied to the electrode S, a portion where the conductive paste 5 does not adhere when the ribbon wire 2 is placed on the electrode S is provided by applying the conductive paste 5 intermittently. This portion becomes moderate slack that prevents excessive tension of the ribbon wire 2, and prevents the glass substrate 10 from cracking or the ribbon wire 2 from being cut due to the difference in linear expansion coefficient between the glass substrate 10 and the ribbon wire 2. In addition, the cost of the conductive paste 5 can be reduced.
The application interval when intermittently applying is, for example, a constant interval of about 0.5 to 7 cm, the first interval is 4 cm, the next interval is 4.5 cm, and the next interval is 5 cm. The resistance of the ribbon wire 2 as a whole can be adjusted by setting it according to the length of the ribbon wire 2, the size of the solar cell submodule 1, or the amount of power generation. Can do.

Then, the manufacturing method of the solar cell module which concerns on embodiment of this invention is demonstrated with reference to figures.
First, as shown in FIG. 4, the back electrode layer 1 </ b> A, the p-type CIS light absorbing layer 1 </ b> B, the high-resistance buffer layer 1 </ b> C, the n-type window layer (transparent conductive film) are formed on the glass substrate 10 by a predetermined film forming process. ) After sequentially laminating 1D, as shown in FIG. 3, a pair of positive and negative electrodes is exposed by exposing a part of the back electrode layer 1A by banding the end portion with a mechanical scribing device, a laser scribing device, or the like. An electrode S is formed.

Next, as shown in FIG. 5, the conductive paste 5 is intermittently applied onto the electrode S formed on the glass substrate 10 by a dispenser or the like.
Then, as shown in FIG. 6, the ribbon wire 2 is placed on the electrode S via the conductive paste 5.

Further, as shown in FIG. 7, the filler 3 and the cover glass 4 are sequentially laminated on the solar cell submodule 1 in which the ribbon wire 2 is placed on the electrode S via the conductive paste 5 and laminated. Apply.
At this time, it is possible to prevent the ribbon wire 2 from being displaced or twisted from the electrode S by the conductive paste 5 attached to the ribbon wire 2.

  In the laminating process, each member laminated as described above is placed in a laminating apparatus, the inside of the apparatus is decompressed, and heated at about 150 ° C. for about 30 minutes. Furthermore, by pressing the above-described members in a stacked state, the hot-melt filler 3 spreads between the solar cell submodule 1 and the cover glass 4 without any gap, and the solar cell submodule 1 and the cover glass 4 are separated. Bonded together.

At the same time, the conductive paste 5 applied on the electrode S by heating is cured to bond the ribbon wire 2 and the electrode S, and between the solar cell submodule 1 and the cover glass 4 by pressing. The entire sandwiched ribbon wire 2 is brought into pressure contact with the electrode S.
Thus, the members are laminated and integrated, and the ribbon wire 2 is attached in surface contact with the electrode S without being displaced from the electrode S.

  The solar cell submodule 1, the ribbon wire 2, the filler 3, and the cover glass 4 constitute the solar cell module according to the present invention. Depending on the specifications, a fluorine-based resin or A back sheet made of aluminum foil or the like is bonded together, or a side end is sealed with a sealing material such as butyl rubber, and then a frame is attached.

According to the present invention, since the ribbon wire 2 is attached to the electrode S formed on the solar cell submodule 1 by the conductive paste 5 without using solder, there is no fear of solder corrosion.
Further, by laminating the solar cell submodule 1, the filler 3 and the cover glass 4, the ribbon wire 2 is sandwiched so as to be pressed by the solar cell submodule 1 and the cover glass 4. The ribbon wire 2 is attached to the electrode S in surface contact, including the portion where the conductive paste 5 is not applied.
Furthermore, in the step of laminating each member as described above, since the ribbon wire 2 is bonded to the electrode S at the same time, the manufacturing process can be reduced and the manufacturing cost can be reduced.

It is a top view which shows the structure which the solar cell module which concerns on embodiment of this invention has. It is A-A 'sectional drawing which shows the structure which the solar cell module which concerns on this embodiment has. It is a schematic diagram which shows the structure of the solar cell submodule which concerns on this embodiment. In this embodiment, it is a schematic diagram which shows the structure of the solar cell submodule after film forming. In this embodiment, it is the top view which showed the state which apply | coated the electrically conductive paste 5 on the electrode S of a solar cell submodule. In this embodiment, it is the top view which showed the state which attached the ribbon wire 2 via the electrically conductive paste 5 on the electrode S of a solar cell submodule. In this embodiment, it is the figure which showed the lamination | stacking order at the time of a lamination process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solar cell submodule 10 Glass substrate 11 Solar cell device 1A Back surface electrode layer 1B p-type CIS type light absorption layer 1C High resistance buffer layer 1D n-type window layer (transparent conductive film)
2 Ribbon wire 3 Filler 4 Cover glass 5 Conductive paste S Electrode

Claims (1)

A solar cell submodule in which a strip-shaped electrode for taking out the electric power generated in the solar cell device is formed and a solar cell device is formed,
A ribbon wire attached to the electrode;
On the solar cell submodule, a cover glass attached to cover the electrode;
Filling between the solar cell submodule and the cover glass, and a filler for adhering and holding the solar cell submodule and the cover glass,
A step of intermittently applying the conductive paste on the electrode,
On an electrode the conductive paste is applied, a step of installing a ribbon wire remembering slack portion where the conductive paste does not adhere,
A step of laminating a filler and a cover glass on the ribbon wire;
The solar cell submodule in which a ribbon wire is installed on the electrode , the filler, and the cover glass are laminated by heating and compressing, whereby the filler is covered with the solar cell submodule. simultaneously with the adhesion between the glass and the ribbon wire bonded held between the solar cell submodule and a cover glass through the filler, the portion where the conductive paste of the ribbon wire is not applied including the install them step by direct contact with surface electrode of the solar cell submodule,
The manufacturing method of the solar cell module characterized by having.

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