WO2011129083A1 - Solar cell module and method for manufacturing same - Google Patents

Abstract

Disclosed is a solar cell module wherein the wiring structure is simplified. The solar cell module is provided with: a solar cell sub-module (12), which is provided with a metal substrate (30) having an insulating layer (32) provided on the surface, and a solar cell section (36) having the positive electrode and the negative electrode provided on the insulating layer (32); and a pair of lead lines (56, 60), which take out power from the solar cell section (36) to the outside. A part of the solar cell sub-module (12) is provided with an electrically connecting section (55), which electrically connects the electrode (38z), i.e., one of the positive and negative electrodes, with the metal substrate (30), and which is composed of a micro crack (52) that reaches the metal substrate (30) by penetrating the electrode (38z) and the insulating layer (32) directly under the electrode, and a solder material (54) embedded in the micro crack (52). The lead line (56) is connected to the electrode (38z) with the electrically connecting section (55) therebetween, by connecting the lead line with the metal substrate (30).

Description

Solar cell module and manufacturing method thereof

The present invention relates to a solar cell module and a manufacturing method thereof, and more particularly to a solar cell module in which a wiring structure of a lead wire for taking out an output from a solar cell submodule in the solar cell module is simplified and a manufacturing method thereof. is there.

Currently, research on solar cells is actively conducted. In a solar cell module, a large number of photoelectric conversion elements having a laminated structure in which a photoelectric conversion layer made of a semiconductor that generates electric charge by light absorption is sandwiched between a back electrode (lower electrode) and a transparent electrode (upper electrode) are connected in series on a substrate. A solar cell submodule.
As the solar cell module, an adhesive sealing material and a protective material are laminated on both the front and back surfaces of the solar cell submodule, and a terminal box for external wiring is integrally assembled on the back surface side. There is known a configuration in which an internal lead wire is wired between a positive electrode and a negative electrode for power extraction formed by distributing to both end regions of the terminal and a connection conductor of a terminal box.
In general, in the solar cell module, the output from the positive electrode and the negative electrode is taken out by connecting a metal ribbon or the like to the electrodes at both ends of the solar cell submodule by soldering, etc., and folding back with an insulating layer in between. It is connected to an electric box (terminal box) (see Patent Documents 1 and 2).

In Patent Document 1, a transparent electrode layer, a photovoltaic thin film semiconductor layer, and a layer including a back electrode layer are sequentially formed on a transparent insulating substrate, and a photovoltaic element divided into a plurality of regions is electrically connected. Thin film solar cell having a bus region that collects power as an end of the connection and collects power, a sealing means including a filler and a back surface protection cover for protecting the surface on which the thin film solar cell is formed, and the thin film solar cell In a thin film solar cell module including connection means for supplying power generated by the battery to the outside, wiring from the bus region to the connection means is embedded in the filler, and another wiring is provided between the wiring and the back electrode layer. A thin film solar cell module in which a glass nonwoven fabric sheet or a 160 ° C. heat resistant synthetic fiber nonwoven fabric sheet embedded in a filler is described.
In the thin-film solar cell module of Patent Document 1, a filler, wiring, a glass nonwoven fabric sheet or a 160 ° C. heat-resistant synthetic fiber nonwoven fabric sheet, a back surface protective cover are laid, assembled, and fixed by a vacuum laminating method.

Further, in Patent Document 1, the bus regions are provided on both sides of the long side of the power generation region of the thin-film solar cell. A solder-plated copper foil is formed in each bus region, and another solder-plated copper foil is connected to the solder-plated copper foil as a lead wire for outputting power to the outside. This lead wire is bent in a substantially L shape so as to protrude from the power generation region of the thin film solar cell in the vicinity of the center of the short side of the power generation region of the thin film solar cell, and is connected to the terminal box outside the back surface protective cover. .

In Patent Document 2, an adhesive sealing material and a protective material are laminated on both front and back surfaces of a thin film solar cell in which a photoelectric conversion element is formed on a film substrate, and a terminal box for external wiring is integrally assembled on the back surface side. In the solar cell module in which an internal lead wire holding insulation is provided between the positive and negative electrodes for power extraction formed at both end regions of the solar cell and the connection conductor of the terminal box, one end of the solar cell electrode A solar cell module in which an internal lead wire connected and pulled out is laid so as to bypass the outside along the side edge of the solar cell, and sandwiched between adhesive sealants together with the solar cell is described. Has been.
In Patent Document 2, a connecting portion on one end side of a lead wire is soldered to an electrode of a solar cell or electrically connected with a conductive adhesive tape. The other end side of the lead wire is bent upright in an L shape toward the back surface side, and then is pulled out to the back surface side of the module through the adhesive sealing material laminated to the solar cell, through the slit hole of the back surface protection material, It is connected by soldering to a connection terminal of a terminal box assembled to the module in accordance with this drawing position.

Japanese Patent No. 312810 JP 2004-31646 A

In the above-mentioned Patent Document 1, wiring of another solder-plated copper foil serving as internal wiring is necessary from the solder-plated copper foil of each bus region to the vicinity of the center of the short side of the power generation region of the thin film solar cell. There is a problem that the cost increases.
Moreover, in patent document 1, in order to fix a filler, wiring, a glass nonwoven fabric sheet or a 160-degree-C heat-resistant synthetic fiber nonwoven fabric sheet, a back surface protection cover, and to assemble after assembly, a separate solder plating copper foil is used. There is a problem in that the surface of the thin-film solar cell is locally curved and deformed along the provided wiring path.
Thus, in patent document 1, since the convex part which the adhesion filling layer and the surface protection material rose along another solder plating copper foil is formed, damage or local stress concentration, as a solar cell There is a problem that the reliability deteriorates.

Furthermore, in Patent Document 2, the wiring of the solar cell submodule and the routing of the lead wire require a long lead wire that retains insulation from the electrode of the solar cell to the terminal box, and thus the cost of the wiring member increases. There is a point.
As described above, in Patent Documents 1 and 2, since the wiring becomes long, the wiring layout becomes complicated, and the complexity of the wiring process at the time of laying the module deteriorates due to the complexity. Furthermore, since the workability of the wiring process at the time of laying is poor, there is a risk of damaging the solar cell, which causes quality problems. As described above, Patent Documents 1 and 2 have problems such as quality and reliability problems.

The present invention has been made in view of the above circumstances, and provides a solar cell module capable of simplifying the wiring structure and simplifying the manufacturing process, and a manufacturing method thereof.

The solar cell module of the present invention is a solar cell submodule comprising a metal substrate having an insulating layer on at least a surface thereof, and a solar cell portion having positive and negative electrodes on the insulating layer,
A solar cell module comprising a pair of lead wires connected to the positive electrode and the negative electrode, respectively, and taking out the output from the solar cell unit;
An electrical connection portion formed in a part of the solar cell submodule and electrically connecting one of the positive electrode and the negative electrode to the metal substrate, the one electrode and the one directly below the one electrode An electrical connection portion comprising a microcrack that penetrates through the insulating layer and reaches the metal substrate and a solder material embedded in the microcrack;
One of the pair of lead wires is connected to the metal substrate, and is connected to the one electrode via the electrical connection portion.

Here, the micro-crack of the electrical connection portion is formed by ultrasonic soldering on the one electrode, and the solder material is the micro-crack during the ultrasonic soldering process. It is embedded inside.

In the solar cell module of the present invention, a plurality of photoelectric conversion elements composed of a back electrode, a photoelectric conversion layer, and a front electrode are connected in series, wherein the solar cell unit is sequentially laminated on the insulating layer,
The back electrode of the end photoelectric conversion element disposed at one end of the plurality of photoelectric conversion elements connected in series constitutes the one electrode,
The micro cracks reach the metal substrate from the solder processing portion on the surface electrode of the edge photoelectric conversion element through the surface electrode, photoelectric conversion layer, and back electrode of the edge photoelectric conversion element. be able to.

Here, the solder processing section refers to a portion that has been subjected to ultrasonic solder processing. That is, the micro crack of the electrical connection portion is formed through the surface electrode, the photoelectric conversion layer, and the back electrode of the photoelectric conversion element by being subjected to ultrasonic soldering from the surface of the end photoelectric conversion element. It has been done.

Alternatively, in the solar cell module of the present invention, a plurality of photoelectric conversion elements each including the back surface electrode, the photoelectric conversion layer, and the front surface electrode, in which the solar cell unit is sequentially stacked on the insulating layer, are connected. ,
The end back electrode connected to the surface electrode of the end photoelectric conversion element disposed at one end of the plurality of photoelectric conversion elements connected in series constitutes the one electrode,
The microcracks may extend from the solder processing portion on the surface of the end back electrode to the metal substrate through the end back electrode.

Here, the solder processing section refers to a portion that has been subjected to ultrasonic solder processing. That is, the micro crack of the electrical connection portion is formed by ultrasonic soldering from the surface of the end back electrode.

In the solar cell module of the present invention, the one lead wire is fixed by a solder material to a region of the insulating layer surface where the solar cell portion is not formed, and penetrates the insulating layer from the surface of the insulating layer. Then, it is desirable to be connected to the metal substrate via a solder material embedded in a microcrack reaching the metal substrate.

Alternatively, the metal substrate comprises a back side insulating layer on the back side,
The one lead wire is fixed to the surface of the back-side insulating layer with a solder material, and the solder material embedded in the microcracks from the surface of the back-side insulating layer through the insulating layer to the metal substrate It is desirable to be connected to the metal substrate.

In the solar cell module of the present invention, the metal substrate is composed of any one of aluminum, stainless steel, a steel material, and a clad material combining these,
The insulating layer is preferably composed of an oxide film, nitride film, or oxynitride film of any of aluminum, silicon, titanium, and iron.

Moreover, in the solar cell module of this invention, it is preferable that the said photoelectric converting layer is comprised with the compound semiconductor of at least 1 sort (s) of chalcopyrite structure.
The compound semiconductor having a chalcopyrite structure is preferably a so-called Ib-IIIb-VIb group compound semiconductor composed of an Ib group element, an IIIb group element, and a VIb group element.
The Ib-IIIb-VIb group compound semiconductor includes at least one type Ib element selected from the group consisting of Cu and Ag, and at least one type IIIb group element selected from the group consisting of Al, Ga, and In. , S, Se, and Te are preferably composed of at least one compound semiconductor composed of at least one VIb group element selected from the group consisting of.

A method for producing a solar cell module of the present invention includes a solar cell submodule comprising a metal substrate having an insulating layer on at least a surface thereof, and a solar cell unit having positive and negative electrodes on the insulating layer. A solar cell module manufacturing method comprising a pair of lead wires connected to the positive electrode and the negative electrode, respectively, and taking out the output from the solar cell part to the outside,
One of the pair of lead wires is connected to the metal substrate;
By performing ultrasonic soldering from one of the positive electrode and the negative electrode, a micro crack is formed from the one electrode through the insulating layer directly below the electrode to reach the metal substrate. By infiltrating the solder material in the inside to form an electrical connection portion between the one electrode and the metal substrate,
The one lead wire is connected to the one electrode through the electrical connection portion.

In the method for manufacturing a solar cell module of the present invention, the one lead wire is ultrasonically soldered to a region of the surface of the insulating layer where the solar cell portion is not formed, thereby It is desirable to form a microcrack that penetrates through the insulating layer and reaches the metal substrate, and to infiltrate the solder material into the microcrack and connect it to the metal substrate.

Alternatively, as the metal substrate, one having a back surface side insulating layer on the back surface,
The one lead wire is ultrasonically soldered to the surface of the back-side insulating layer to form a microcrack that penetrates the back-side insulating layer and reaches the metal substrate. It is desirable to infiltrate the solder material and connect it to the metal substrate.

The solar cell module of the present invention penetrates through one electrode and the insulating layer immediately below the metal substrate so that either the positive electrode or the negative electrode of the solar cell portion is electrically connected to a part of the submodule. It has an electrical connection part consisting of a microcrack that reaches the substrate and a solder material embedded in the microcrack, and one of the pair of lead wires is connected to the metal substrate, and the metal substrate is used as a conductor for electricity Since it is connected to one electrode via the connection portion, the metal substrate itself can be energized as a conductor, and it is not necessary to draw a long lead wire to connect to the outside at least, The wiring structure can be simplified. For this reason, wiring length can be shortened in the whole solar cell module. Thereby, the material cost concerning wiring can be held down. Furthermore, costs such as module manufacturing process costs and solar cell module laying work costs can be reduced.

In addition, the electrical connection for energizing the metal substrate and one of the electrodes is formed by forming a microcrack by performing ultrasonic soldering from one electrode and penetrating the solder material into the microcrack. Therefore, it is not necessary to remove the insulating layer by etching to expose the metal substrate, and the lead wire attaching process can be simplified.

Further, according to the present invention, since the wiring structure can be simplified, the quality and reliability of the solar cell module can be improved. Furthermore, since the position of the junction box of the solar cell module can be not the center of the solar cell module but the end, the aesthetic appearance is excellent and the commercial value of the solar cell module can be improved. .

According to the method for manufacturing a solar cell module of the present invention, the electrical connection part for connecting one of the positive electrode and the negative electrode to the substrate electrode is formed by performing ultrasonic soldering on the one electrode. The process of removing the metal substrate by etching or the like is not necessary, and the connection part can be formed by a very simple process, and as a result, the module manufacturing process can be simplified. Productivity can be improved.

The typical perspective view showing the solar cell module of the embodiment of the present invention. The typical top view which shows the solar cell submodule used for the solar cell module of embodiment of this invention. IIIA-IIIA cross-sectional view of the solar cell submodule shown in FIG. IIIB-IIIB cross section of the solar cell submodule shown in FIG. The typical perspective view which shows a part of wiring structure of the solar cell module of embodiment of this invention. Schematic plan view showing a solar cell submodule of another configuration VIA-VIA cross section of the solar cell sub-module shown in FIG. VIB-VIB cross-sectional view of the solar cell submodule shown in FIG.

Hereinafter, the solar cell module of the present invention and the manufacturing method thereof will be described with reference to the drawings. In each drawing, the scale of each part is appropriately changed for easy visual recognition.

<Solar cell module>
FIG. 1 is a perspective view schematically showing a configuration of a solar cell module 10 according to an embodiment of the present invention. FIG. 2 is a schematic plan view of a solar cell submodule used in the solar cell module according to the first embodiment of the present invention, and FIGS. 3A and 3B show respective end portions of the solar cell submodule shown in FIG. FIG.

As shown in FIGS. 1 and 3A, a solar cell module 10 according to an embodiment of the present invention includes a solar cell unit 36 including positive and negative electrodes on a metal substrate 30 and an insulating layer 32 on the surface of the metal substrate. A solar cell submodule 12 and an adhesive filling layer 14, a water vapor barrier layer (protective layer) 16, and a surface protective layer (protective layer) 18 disposed on the surface side (lower surface side in FIG. 1) of the solar cell submodule 12. An adhesive filling layer 20 and a back sheet (protective layer) 22 disposed on the back surface side (upper surface side in FIG. 1) of the solar cell sub module 12, and a solar cell sub module 12 protruding from the back sheet 22. The first and second lead wires 56 and 60 for taking out the output of the negative electrode and the negative electrode (one electrode) to which the second lead wire 60 (one lead wire) is connected The has an electrical connection portion 55 for conducting the metal substrate 30, and a terminal box 24 that the first and second leads 56 and 60 are connected.

In the solar cell module 10, the solar cell submodule 12, the adhesive filling layer 14, the water vapor barrier layer 16 and the surface protective layer 18 disposed on the surface side of the solar cell submodule 12, and the back surface side of the solar cell submodule 12 The adhesive filling layer 20 and the back sheet 22 arranged in are laminated and integrated by, for example, a vacuum laminating method.
Here, the surface side of the solar cell submodule 12 is a surface that receives light for obtaining electric power, and the back surface side is an opposite side of the surface. The solar cell module of FIG. 1 is configured to receive light from the arrow direction, and in FIG. 1, the surface is the lower surface side.

The terminal box 24 is for taking out the electric power obtained by the solar cell module 10 to the outside of the solar cell module 10, and is connected to a power feeding cable or the like. The terminal box 24 is fixed by being adhesively sealed with, for example, a silicone resin around the corner portion of the surface 22a of the back sheet 22.

The surface-side adhesion filling layer 14 is inserted between the solar cell submodule 12 and the water vapor barrier layer 16 and between the water vapor barrier layer 16 and the surface protective layer 18 to seal the solar cell submodule 12. The solar cell submodule 12, the water vapor barrier layer 16, and the surface protective layer 18 are adhered to each other. Similarly, the adhesive filling layer 20 on the back side is for sealing and protecting the solar cell submodule 12 and for adhering to the back sheet 22.
For the adhesive filling layers 14 and 20, for example, EVA (ethylene vinyl acetate) or PVB (polyvinyl butyral) is used.

The water vapor barrier layer 16 is for protecting the solar cell submodule 12 from moisture. As the water vapor barrier layer 16, for example, a layer in which an inorganic layer made of SiO ₂ , SiN, Al ₂ O ₃ or the like is formed on a transparent film such as PET or PEN, or a transparent film such as PET or PEN is made of SiO. _2. A sandwich structure in which an inorganic layer made of SiN or the like and an acrylic resin or the like is further formed and the inorganic layer is sandwiched between resin layers is used.
The configuration of the water vapor barrier layer 16 is not particularly limited as long as the water vapor transmission rate, the oxygen transmission rate, and the like satisfy predetermined performance.

The surface protective layer 18 protects the solar cell submodule 12 from dirt and the like, and suppresses a decrease in the amount of incident light on the solar cell submodule 12 due to dirt and the like. As this surface protective layer 18, for example, a fluorine resin film is used. As this fluororesin, for example, ETFE (ethylene tetrafluoroethylene) is used. Further, the thickness of the surface protective layer 18 is, for example, 20 to 200 μm.

The back sheet 22 is for protecting the solar cell module 10 from the back side and ensuring insulation of the solar cell module 10. The back sheet 22 is made of a resin film made of PVF (polyvinyl fluoride), PET, PEN or the like and sandwiched with an aluminum foil. The configuration of the back sheet 22 is not particularly limited.

(Solar cell sub-module)
As shown in FIG. 2, FIG. 3A, and FIG. 3B, the solar cell submodule 12 of this embodiment includes a metal substrate 30 that includes insulating layers 32 and 34 on the entire surface 30 a and back surface 30 b, respectively, and an insulating layer 32. A plurality of photoelectric conversion elements (solar battery cells) 50 formed on the front surface 32a of the solar cell unit 36 having an integrated structure in which the photovoltaic cells are connected in series. On the surface of the submodule 12, a frame-shaped insulating region where the insulating layer surface 32 a is exposed is provided so as to surround the solar cell portion 36. This region is provided by sequentially laminating each layer of the solar cell portion 36 on the entire surface of the substrate and then removing only the peripheral region with a laser.

As shown in FIG. 3A and FIG. 3B, the solar cell unit 36 includes a back electrode 38, a photoelectric conversion layer 40 made of a compound semiconductor, a buffer layer 42, and a surface electrode (transparent electrode) on the insulating layer 32 on the surface of the metal substrate 30. ) 44 are sequentially stacked, and a plurality of photoelectric conversion elements 50 separated into strips extending in the short side direction of the substrate are connected in series by connecting the back electrode 38 and the transparent electrode 44 between the adjacent photoelectric conversion elements 50. Being done. Each photoelectric conversion element 50 includes a back electrode 38, a photoelectric conversion layer 40, a buffer layer 42, and a transparent electrode 44.

Each back electrode 38 is disposed and formed on the surface 32 a of the insulating layer 32 so as to be separated from the adjacent back electrode 38 by the first separation groove 39. The photoelectric conversion layer 40 is formed on the back electrode 38 while filling the first separation groove 39. A buffer layer 42 is formed on the surface of the photoelectric conversion layer 40. The photoelectric conversion layer 40 and the buffer layer 42 of each photoelectric conversion element are separated from the photoelectric conversion layer 40 and the buffer layer 42 of the adjacent photoelectric conversion element by a second separation groove 43 reaching the back electrode 38. The second separation groove 43 is formed at a position different from the first separation groove 39 of the back electrode 38.

Further, a transparent electrode 44 is formed on the surface of the buffer layer 42 while filling the groove 43. Furthermore, a third separation groove 45 that penetrates the transparent electrode 44, the buffer layer 42, and the photoelectric conversion layer 40 and reaches the back electrode 38 is formed. Each photoelectric conversion element 50 has a configuration in which the back electrode 38 and the transparent electrode 44 of the adjacent photoelectric conversion element are connected in series by being connected by a third separation groove 45.

In the photoelectric conversion element 50 of the present embodiment, for example, the back electrode 38 is made of a molybdenum electrode, the photoelectric conversion layer 40 is made of CIGS, the buffer layer 42 is made of CdS, and the transparent electrode 44 is made of ZnO. Yes.
When light enters the photoelectric conversion element 50 from the transparent electrode 44 side, the light passes through the transparent electrode 44 and the buffer layer 42, and an electromotive force is generated in the photoelectric conversion layer 40. A current directed to 38 is generated. At this time, in FIG. 2 and FIG. 3, in the solar cell unit 36 configured by connecting a plurality of photoelectric conversion elements 50 in series, the back electrode 38 of the photoelectric conversion element 50 a at the left end is a positive electrode (plus electrode). Thus, the back electrode 38 of the photoelectric conversion element 50z at the right end becomes a negative electrode (negative electrode).

In addition, the solar cell part 36 of this embodiment can be manufactured with the manufacturing method of a well-known CIGS type solar cell, for example. At this time, the first to third separation grooves 39, 43, and 45 can be formed by laser scribe or mechanical scribe.

(Electrical connection)
As shown in FIG. 2 and FIG. 3A, the electrical connection portion 55 includes a back electrode 38 z (a negative electrode of the solar cell portion 36) of the end photoelectric conversion element 50 z disposed at one end of the solar cell portion 36, and the metal substrate 30. It is provided in order to ensure electrical continuity.

The electrical connecting portion 55 penetrates through the end photoelectric conversion element 50z and the insulating layer 32 directly below the element 50z formed by performing ultrasonic soldering from the surface of the transparent electrode 44 of the end photoelectric conversion element 50z. A microcrack 52 reaching the metal substrate 30 and a solder material 54 penetrating from the surface of the transparent electrode 44 and embedded in the microcrack 52 are configured. Further, the solder material 54 remains on the surface of the transparent electrode 44 as a trace of the ultrasonic soldering process (solder processing part). The end photoelectric conversion element 50z on which the electrical connection portion 55 is formed includes the back surface electrode 38z, the photoelectric conversion layer 40, the buffer layer 42, and the transparent electrode 44, but does not have a photoelectric conversion function.

The electrical connection portion 55 is preferably provided periodically at a plurality of locations along the strip-shaped back electrode 38z. For example, it is provided every 2 cm. Although it may be provided continuously along the strip-shaped back electrode 38z, it is sufficient to periodically provide it at a plurality of locations, and it is preferable because the processing step time can be shortened compared to continuous provision.

(Lead)
As shown in FIG. 2, in this embodiment, a pair of lead wires 56 and 60 for taking out the output of the solar cell unit 36 are connected to one corner of the solar cell submodule 12. Here, the first lead wire 56 is connected to the positive electrode, and the second lead wire 60 is connected to the negative electrode.

As shown in FIGS. 2 and 3B, in the solar cell submodule 12, the back electrode 38 of the photoelectric conversion element 50 a at the left end of the solar cell unit 36, which constitutes the positive electrode of the solar cell unit 36, is provided to protrude to the left side. The first lead wire 56 is connected to the surface of the protruding back electrode 38a (the shaded area in FIG. 2). The first lead wire 56 is connected to the back electrode 38a by normal soldering that is not ultrasonic soldering or by a conductive paste such as silver paste. In the present embodiment, the first lead wire 56 is directly connected to the back electrode 38a. For example, a conductive member such as a tin-plated copper ribbon or a conductive tape is provided on the back electrode 38a. It may be connected to the back electrode 38a through a conductive member. By providing the conductive tape, the strength of the back electrode 38a can be reinforced.

In addition, when the photoelectric conversion layer 40, the buffer layer 42, and the transparent electrode 44 are formed in the part to which the first lead wire 56 of the back electrode 38a is connected, these layers are formed by laser scribe or mechanical scribe. And the back electrode 38a is exposed.

The second lead wire 60 is ultrasonically soldered to the insulating layer surface 32a in the frame insulating region in the vicinity of the back electrode 38a and fixed by the solder material 64, and penetrates the insulating layer 32 from the surface of the insulating layer 32. It is connected to the metal substrate 30 via a solder material 64 embedded in a microcrack 62 reaching the metal substrate 30. During the ultrasonic soldering, the microcracks 62 are formed and the solder material 64 penetrates into the microcracks 62. The second lead wire 60 is thus connected to the metal substrate 30, and is electrically connected to the negative electrode 38 z connected through the electrical connection portion 55 with the metal substrate 30 as a conductor. Further, the second lead wire 60 is insulated by the insulating sleeve 61 except for the connection portion.

FIG. 4 is a partial perspective view schematically showing the wiring state of the lead wires in the solar cell module 10 according to the present embodiment.

Although illustration of the insulating sleeves 57 and 61 is omitted in FIG. 4, the first lead wire 56 is bent in a substantially U-shape and is wired along the side surface 30 c of the substrate 30 and the surface 22 a of the back sheet 22. The tip 56a is bent so as to be substantially perpendicular to the surface 22a of the back sheet 22, and is bent upright in a substantially L shape.
Similarly to the first lead wire 56, the second lead wire 60 is also bent in a substantially U shape and wired along the side surface 30 c of the substrate 30 and the surface 22 a of the back sheet 22, and the metal substrate 30. Further, the front end 56a is bent so as to be substantially perpendicular to the surface 22a of the back sheet 22, and is bent upright in a substantially L shape.
As shown in FIG. 1, the first lead wire 56 and the second lead wire 60 are each connected to a terminal (not shown) of the terminal box 24 in a state of protruding from the back sheet 22.

In the present embodiment, when the electric power is taken out from the solar cell submodule 12, the second lead wire connected to one electrode (here, the negative electrode) is connected to the other electrode (here, the metal substrate 30 as a conductor). By connecting to the metal substrate 30 in the vicinity of the positive electrode), it is not necessary to wire the second lead wire 60 of the negative electrode so as to surround the periphery of the solar cell portion 36, and at least the wiring of the second lead wire 60 The length can be shortened and the wiring structure can be simplified.
For this reason, wiring length can be shortened as the whole solar cell module 10, and the material cost concerning wiring can be held down. Furthermore, costs such as module manufacturing process costs and solar cell module laying work costs can be reduced.

Moreover, according to this embodiment, since the wiring structure can be simplified, the quality and reliability of the solar cell module 10 can be improved. Furthermore, since the mounting position of the terminal box 24 of the solar cell module 10 can be not near the center of the solar cell module 10 but in the vicinity of the corner portion, the appearance is excellent and the commercial value of the solar cell module 10 is improved. Can be improved.

Furthermore, since the first lead wire 56 of the positive electrode and the second lead wire 60 of the negative electrode are brought close to each other and can be immediately connected to the terminal box 24 on the back surface side of the metal substrate 30, the first The lengths of the lead wire 56 and the second lead wire 60 on the back surface 30b side of the metal substrate 30 can be shortened. Thereby, the simple high quality and highly reliable solar cell module 10 of the structure without the convex part by the 1st lead wire 56 and the 2nd lead wire 60 can be provided.

In addition, since the electrical connection portion 55 for conducting one electrode and the metal substrate 30 can be formed by a very simple method of ultrasonic soldering, the lead wire attaching process can be simplified and the module manufacturing process cost can be reduced. Can be further suppressed.

Below, the detail of the solar cell submodule 12 is demonstrated.
(substrate)
Although the series resistance of the metal substrate 30 serving as a current path varies depending on the metal material used, it is as shown in Table 1 below when the module size is 120 cm long × 60 cm wide. As shown in Table 1 below, even in a SUS430 substrate having a high resistivity, the series resistance is at a level that does not cause a problem. In addition, the short side series resistance shown in following Table 1 is a series resistance in the long side direction of a module.

In the present embodiment, the metal substrate 30 has the insulating layers 32 and 34 formed on the front surface 30a and the back surface 30b. The insulating layers 32 and 34 are, for example, insulating oxide films having a plurality of pores formed by anodizing a metal substrate. This insulating oxide film has a high insulating property. The insulating layer only needs to be provided on at least the surface of the metal substrate 30.
As the metal substrate 30, a material in which a metal oxide film generated on the front and back surfaces of the metal substrate 30 by anodic oxidation is an insulator can be used.

Specifically, as the metal substrate 30, aluminum (Al), zirconium (Zr), titanium (Ti), magnesium (Mg), copper (Cu), niobium (Nb), tantalum (Ta) and iron (Fe) A substrate made of an alloy of these metals can also be used. From the viewpoint of cost and characteristics required for the solar cell, aluminum is most preferable as the metal substrate 30.
As the metal substrate 30, a so-called clad material obtained by rolling or hot-plating the above-described metal usable for the metal substrate 30 on the surface of a steel plate such as mild steel or stainless steel can be used for improving heat resistance. .
In addition, it is preferable that the metal substrate 30 of this embodiment is provided with flexibility (flexibility). Thereby, the solar cell module obtained can be made flexible.

When an aluminum plate is used for the metal substrate 30, the insulating layers 32 and 34 can be formed by anodizing and performing a specific sealing treatment. The manufacturing process of the insulating layers 32 and 34 may include various processes other than the essential processes.
In this embodiment, when an aluminum plate is used for the metal substrate 30, for example, a degreasing step for removing adhering rolling oil, a desmut treatment step for dissolving a smut on the surface of the aluminum plate, and a roughening of the surface of the aluminum plate The insulating layers 32 and 34 are formed through a roughening treatment step, an anodizing treatment step for forming an anodized film on the surface of the aluminum plate, and a sealing treatment for sealing the micropores of the anodized film. It is preferable to use a substrate for the above.

The thicknesses of the insulating layers 32 and 34 formed of the anodized aluminum oxide film are not particularly limited as long as they have insulating properties and surface hardness that prevents damage due to mechanical shock during handling, but are too thick. In some cases, there is a problem in terms of flexibility. Therefore, the preferable thickness of the insulating layers 32 and 34 formed of the aluminum oxide film by anodic oxidation is 0.5 to 50 μm, and the thickness of the insulating layer can be controlled by the electrolysis time of the anodic oxidation treatment. it can.

Further, the insulating layers 32 and 34 are not limited to the aluminum oxide film formed by anodic oxidation. Examples of the insulating layers 32 and 34 include an aluminum oxide film, a silicon oxide film, a titanium oxide film, and an iron oxide film. Examples of the insulating layers 32 and 34 include an aluminum nitride film, a silicon nitride film, a titanium nitride film, and an iron nitride film. Further examples include an aluminum nitrogen oxide film, a silicon nitrogen oxide film, a titanium nitrogen oxide film, and an iron nitrogen oxide film.
These insulating layers 32 and 34 can be formed by, for example, an anodic oxidation method, a CVD method, a PVD method, or a sol-gel method. The thickness of the insulating layers 32 and 34 is preferably 1 to 100 μm, and more preferably 10 to 50 μm.

(Back electrode)
The back electrode 38 is made of, for example, Mo, Cr, or W, and a combination thereof. The back electrode 38 may have a single layer structure or a laminated structure such as a two-layer structure.
The back electrode 38 preferably has a thickness of 100 nm or more, and more preferably 0.2 to 0.8 μm.
The method for forming the back electrode 38 is not particularly limited, and can be formed by a vapor deposition method such as an electron beam evaporation method or a sputtering method.

(Transparent electrode)
The transparent electrode 44 is an electrode arranged on the light incident side, and needs to have translucency in order to make light incident on the photoelectric conversion layer.
The transparent electrode 44 is made of, for example, ZnO to which Al, B, Ga, Sb, In or the like is added, ITO (indium tin oxide), SnO ₂ or a combination thereof. The transparent electrode 44 may have a single layer structure or a laminated structure such as a two-layer structure. Further, the thickness of the transparent electrode 44 is not particularly limited, and is preferably 0.3 to 1 μm.

(Buffer layer)
The buffer layer 42 has functions such as protecting the photoelectric conversion layer 40 when the transparent electrode 44 is formed and band discontinuous matching, and transmits light incident from the transparent electrode 44 to the photoelectric conversion layer 40. It is necessary to have translucency.
The buffer layer 42 is made of, for example, CdS, ZnS, ZnO, ZnMgO, ZnS (O, OH), or a combination thereof.
The buffer layer 42 preferably has a thickness of 0.03 to 0.1 μm. The buffer layer 42 can be formed by, for example, a CBD (chemical bath deposition) method.

(Photoelectric conversion layer)
The photoelectric conversion layer 40 is a layer that generates a charge (electromotive force) by absorbing light that has passed through the transparent electrode 44 and the buffer layer 42. In the present embodiment, the composition of the photoelectric conversion layer 40 is not particularly limited, and is, for example, at least one compound semiconductor having a chalcopyrite structure. Specifically, at least one selected from the group consisting of a compound semiconductor composed of a group Ib element such as a so-called CIS group, a group IIIb element and a group VIb element, or at least one compound semiconductor such as a CIGS group, Cu and Ag. One group Ib element, at least one group IIIb element selected from the group consisting of Al, Ga and In, and at least one group VIb element selected from the group consisting of S, Se and Te At least one compound semiconductor comprising:

Further, since the light absorption rate is high and high photoelectric conversion efficiency is obtained, the photoelectric conversion layer 40 is composed of at least one group Ib element selected from the group consisting of Cu and Ag, and a group consisting of Al, Ga, and In. It is preferably at least one compound semiconductor composed of at least one group IIIb element selected from the group consisting of S, Se, and Te, and at least one group VIb element selected from the group consisting of S, Se, and Te. As the compound _{semiconductor, CuAlS 2, CuGaS 2, CuInS} 2, CuAlSe 2, CuGaSe 2, CuInSe 2 (CIS), AgAlS 2, AgGaS 2, AgInS 2, AgAlSe 2, AgGaSe 2, AgInSe 2, AgAlTe 2, AgGaTe 2 , AgInTe ₂ , Cu (In _1-x Ga _x ) Se ₂ (CIGS), Cu (In _1-x Al _x ) Se ₂ , Cu (In _1-x Ga _x ) (S, Se) ₂ , Ag (In _1-x Ga _x ) Se ₂ , Ag (In _1-x Ga _x ) (S, Se) _{2 and the} like.

The photoelectric conversion layer 40 particularly preferably includes CuInSe ₂ (CIS) and / or Cu (In, Ga) Se ₂ (CIGS) in which Ga is dissolved. CIS and CIGS are semiconductors having a chalcopyrite crystal structure, have high light absorption, and high photoelectric conversion efficiency has been reported. Moreover, there is little degradation of efficiency by light irradiation etc. and it is excellent in durability.

The photoelectric conversion layer 40 contains impurities for obtaining a desired semiconductor conductivity type. Impurities can be contained in the photoelectric conversion layer 40 by diffusion from adjacent layers and / or active doping. In the photoelectric conversion layer 40, the constituent elements and / or impurities of the I-III-VI group semiconductor may have a concentration distribution, and a plurality of layer regions having different semiconductor properties such as n-type, p-type, and i-type May be included.
For example, in the CIGS system, when the Ga amount in the photoelectric conversion layer 40 has a distribution in the thickness direction, the band gap width / carrier mobility and the like can be controlled, and the photoelectric conversion efficiency can be designed high.

The photoelectric conversion layer 40 may contain one or more semiconductors other than the group I-III-VI semiconductor. Semiconductors other than I-III-VI group semiconductors include semiconductors composed of group IVb elements such as Si (group IV semiconductors), semiconductors composed of group IIIb elements such as GaAs and group Vb elements (group III-V semiconductors), and Examples thereof include semiconductors composed of IIb group elements such as CdTe and VIb group elements (II-VI group semiconductors). The photoelectric conversion layer 40 may contain an optional component other than a semiconductor and impurities for obtaining a desired conductivity type as long as the characteristics are not hindered.
Further, the content of the group I-III-VI semiconductor in the photoelectric conversion layer 40 is not particularly limited. The content of the group I-III-VI semiconductor in the photoelectric conversion layer 40 is preferably 75% by mass or more, more preferably 95% by mass or more, and particularly preferably 99% by mass or more.

Any method may be applied as a method of forming the CIGS layer. As a method for forming a CIGS layer, a multi-source co-evaporation method, a selenization method, a sputtering method, a hybrid sputtering method, a mechanochemical process method, and the like are known. In addition, screen printing, proximity sublimation, MOCVD, spraying, and the like may be used.

<Method for manufacturing solar cell module>
As a method for manufacturing the solar cell module according to the embodiment of the present invention, a method for manufacturing the solar cell module 10 according to the above embodiment will be described.
The manufacturing method of the solar cell module 10 according to the present embodiment includes a lead wire attaching step for attaching a lead wire for extracting power to the solar cell sub module 12, and adhesive filling on the front surface side and the back surface side of the solar cell sub module 12, respectively. A lay-up process for arranging the layer and the protective layer, and a laminating process for performing a laminating process.

(Lead wire installation process)
The lead wire attaching step is a step of connecting the pair of lead wires 56 and 60 to the positive electrode and the negative electrode of the solar cell portion 36, respectively, and includes the formation of the electrical connecting portion 55 here.

First, the photoelectric conversion layer 40, the buffer layer 42, and the transparent electrode 44 on the back electrode 38a at the left end in FIG. 2, which is the positive electrode of the solar cell portion 36 of the solar cell submodule 12, are removed by laser scribe or mechanical scribe, and the back surface The electrode 38a is exposed.

The electrical connection portion 55 is formed by performing an ultrasonic soldering process on the surface of the transparent electrode 44 of the right end photoelectric conversion element 50z in FIG. In the ultrasonic soldering process, the tip of the soldering iron is brought to a temperature of about 300 to 500 ° C., and the surface oxide is removed from the soldering process by generating ultrasonic waves of 2 to 3 W and several tens of kHz from the tip. However, soldering is performed.
When ultrasonic soldering is performed on the surface of the transparent electrode 44 of the end photoelectric conversion element 50z to obtain an ultrasonic intensity of a predetermined level or more, the transparent electrode 44, the buffer layer 42, the photoelectric conversion layer 40, and the negative electrode of the solar cell unit 36 are configured. A plurality of microcracks 52 that penetrate through the back electrode 38z and further through the insulating layer 32 directly below the back electrode 38z and reach the metal substrate 30 are generated, and the solder material 54 permeates from above the transparent electrode 44 so that the inside of the microcrack 52 is inside. It is embedded with solder material 54. The back electrode 38 z can be electrically connected to the metal substrate 30 by the solder material 54 embedded in the microcrack 52.
More specifically, for example, a Kuroda Techno lead-free solder cerasolzer 217 is used as the solder material 54, and the ultrasonic strength is set to 2 W and the soldering iron tip temperature is 450 ° C. by the Kuroda Techno ultrasonic soldering device sun bonder. The electrical connection portion 55 is formed by ultrasonic soldering. On the surface of the strip-shaped end photoelectric conversion element 50z, a plurality of electrical connection portions 55 are formed by ultrasonic soldering, for example, every 2 cm in the length direction.

One of the pair of lead wires (second lead wire 60) is connected to the metal substrate 30, and the other (first lead wire 56) is connected to the back electrode 38a at the left end in FIG. Connecting.
The first lead wire 56 is directly connected and fixed to the back electrode 38a using silver paste. Further, the second lead wire 60 is ultrasonically soldered to the insulating layer surface 32a in the frame insulating region near the back electrode 38a. The lead wire 60 is fixed to the surface 32a of the insulating layer 32 with the solder material 64 by ultrasonic soldering, and the microcracks that penetrate the insulating layer 32 and reach the metal substrate 30 as in the case of forming the electrical connection portion 55. A plurality of 62 are formed, and the solder material 64 is infiltrated and embedded in the microcracks 62. Again, ultrasonic soldering is performed by setting the tip of the soldering iron to a temperature of about 300 to 500 ° C. and generating ultrasonic waves of 2 to 3 W and several tens of kHz from the tip.

By forming the electrical connection portion 55 as described above and connecting the second lead wire 60 to the metal substrate 30, the second lead wire 60 is connected to the negative electrode (via the metal substrate 30 and the electrical connection portion 55). It can be connected to the back electrode 38z). Note that either the formation of the electrical connection portion or the connection of the lead wires 56 and 60 may be performed first.

The second lead wire 60 may be directly connected and fixed to the metal substrate 30 by removing a part of the insulating layer 32 by laser scribe or mechanical scribe. However, as in this embodiment, the second lead wire 60 is insulated by ultrasonic soldering. If it is the method of fixing on the layer 32, since it is not necessary to provide the process of removing a part of insulating layer 32, a manufacturing process becomes simpler.

(Layup process)
In the lay-up process, first, the adhesion filling layer 14, the water vapor barrier layer 16, and the surface protective layer 18 are disposed on the surface side of the solar cell submodule 12.
At this time, in the solar cell submodule 12, the first lead wire 56 and the second lead wire 60 are bent in a state where they are kept parallel to each other and turned around the back surface 30 b of the metal substrate 30. The tips 56 a and 60 a are projected from the back sheet 22 through through holes provided at predetermined positions of the arranged adhesive filling layer 20 and the back sheet 22.

(Lamination process)
In the state where the adhesive filling layer 14, the water vapor barrier layer 16 and the surface protective layer 18 are arranged on the surface side of the solar cell submodule 12 as described above, for example, lamination is performed at 150 ° C. for 20 minutes using a vacuum laminator. Integrate.

(Post-process)
Thereafter, the first lead wire 56 and the second lead wire 60 are bent, and are bent upright on the surface 22a of the backsheet 22 in a substantially L shape.
Further, the terminals of the terminal box 24 are connected to the tips 56 a and 60 a of the first lead wire 56 and the second lead wire 60. Then, the terminal box 24 is bonded and sealed, for example, with a silicone resin in the vicinity of the corner portion of the surface 22a of the back sheet 22.
As described above, the solar cell module 10 of the embodiment shown in FIG. 1 can be manufactured.

<Design change example>
A design change example of the solar cell submodule, the lead wire, and the electrical connection portion will be described.
FIG. 5 is a schematic plan view of a solar cell submodule 112 of a design change example used in the solar cell module according to the embodiment of the present invention. FIGS. 6A and 6B are respectively the solar cell submodules shown in FIG. It is a schematic cross section of an edge part.

As shown in FIG. 5, in the present design modification example, the connection position of the second lead wire 60 to the solar cell submodule 112 and the configuration of the electrical connection portion 55 are the solar cell submodule 12 shown in FIG. Different from reference). Hereinafter, differences from the solar cell submodule 12 will be mainly described.

As shown in FIG. 5 and FIG. 6A, the solar cell submodule 112 is adjacent to the right end photoelectric conversion element 50z in FIG. 5 arranged at one end of the plurality of photoelectric conversion elements 50 connected in series. An end back electrode 38α connected to the surface electrode 44 of the partial photoelectric conversion element 50z is provided, and the end back electrode 38α constitutes one electrode (here, the negative electrode) of the solar cell portion 36.

The electrical connection portion 55 is subjected to ultrasonic soldering from the surface of the end back electrode 38α to penetrate the insulating layer 32 immediately below the electrode 38α from the surface of the end back electrode 38α to the metal substrate 30. The microcrack 52 and the solder material 54 which penetrates from the surface of the transparent electrode 44 and is embedded in the microcrack 52 are configured. The photoelectric conversion layer 40, the buffer layer 42, and the transparent electrode 44 provided on the end back electrode 38α are removed by laser scribe or mechanical scribe to expose the end back electrode 38α, and then the end back electrode 38α. The electrical connection portion 55 can be formed by performing ultrasonic soldering from the surface.
In FIG. 5, the shaded area indicates a portion where the back electrode 38 is exposed on the surface of the submodule.

As shown in FIGS. 5 and 6B, a conductive tape 46 is pressure-bonded to the surface of the back electrode 38a at the left end in FIG. 5 to which the first lead wire 56 is connected. For example, an embossed conductive tape manufactured by Sumitomo 3M Limited is pressure-bonded onto the back electrode 38a at 2 kg / cm ² . This conductive tape ensures good conductivity and can reinforce the strength of the back electrode 38a.

The second lead wire 60 is ultrasonically soldered to the insulating layer 34 formed on the back surface side of the metal substrate 30 and fixed by the solder material 64, and the micro crack 62 that penetrates the insulating layer 34 and reaches the metal substrate 30. It is connected to the metal substrate 30 via a solder material 64 embedded therein.

Since the second lead wire 60 is fixed to the insulating layer 34 on the back surface side of the metal substrate 30, it is not necessary to route the side surface 30 c of the metal substrate 30, and the distance to the back sheet 22 can be set to the solar cell sub It can be slightly shorter than the module 12. Therefore, the workability in the manufacturing process can be further improved, and the material cost can be further reduced.

Other configurations are substantially the same as those of the solar cell submodule 12 shown in FIG. 2, and can be manufactured in the same manner.

Also in this example, since the ultrasonic soldering process and the ultrasonic soldering are used for the connection of the electrical connection portion 55 and the second lead wire 60 to the metal substrate, the same effect as the first embodiment is obtained. be able to.

In the above-described embodiment, the first lead wire 56 is connected to the positive electrode and the second lead wire 60 is connected to the negative electrode. However, the present invention is not limited to this. The polarity with respect to the second lead wire 60 may be reversed, and in this case as well, the same effects are achieved in any of the above-described embodiments.

Furthermore, in the above-described embodiment, the terminal box 24 is provided. However, the present invention is not limited to this, and the terminal box provided outside the solar cell module is not limited to the terminal box provided in the solar cell module. The first lead wire 56 and the second lead wire 60 may be connected.

Claims (10)

1. A solar cell submodule comprising at least a metal substrate provided with an insulating layer on the surface, and a solar cell part provided with positive and negative electrodes on the insulating layer;
   A solar cell module comprising a pair of lead wires connected to the positive electrode and the negative electrode, respectively, and taking out the output from the solar cell unit;
   An electrical connection portion formed in a part of the solar cell submodule and electrically connecting one of the positive electrode and the negative electrode to the metal substrate, the one electrode and the one directly below the one electrode An electrical connection portion comprising a microcrack that penetrates through the insulating layer and reaches the metal substrate and a solder material embedded in the microcrack;
   One of the pair of lead wires is connected to the metal substrate, and is connected to the one electrode through the electrical connection portion.
2. A plurality of photoelectric conversion elements composed of a back electrode, a photoelectric conversion layer, and a front electrode are connected in series, wherein the solar cell unit is sequentially laminated on the insulating layer,
   The back electrode of the end photoelectric conversion element disposed at one end of the plurality of photoelectric conversion elements connected in series constitutes the one electrode,
   The micro-crack extends from the solder processing portion on the surface electrode surface of the edge photoelectric conversion element to the metal substrate through the surface electrode, photoelectric conversion layer, and back electrode of the edge photoelectric conversion element. The solar cell module according to claim 1.
3. A plurality of photoelectric conversion elements composed of a back electrode, a photoelectric conversion layer, and a front electrode are connected in series, wherein the solar cell unit is sequentially laminated on the insulating layer,
   The end back electrode connected to the surface electrode of the end photoelectric conversion element disposed at one end of the plurality of photoelectric conversion elements connected in series constitutes the one electrode,
   2. The solar cell module according to claim 1, wherein the microcrack extends from the solder processing portion on the surface of the end back electrode to the metal substrate through the end back electrode. 3.
4. The one lead wire is fixed by a solder material in a region of the insulating layer surface where the solar cell portion is not formed, and the micro crack extends from the surface of the insulating layer to the metal substrate through the insulating layer. The solar cell module according to any one of claims 1 to 3, wherein the solar cell module is connected to the metal substrate via a solder material embedded therein.
5. The metal substrate comprises a back side insulating layer on the back side,
   The one lead wire is fixed to the surface of the back-side insulating layer with a solder material, and the solder material embedded in the microcracks from the surface of the back-side insulating layer through the insulating layer to the metal substrate 4. The solar cell module according to claim 1, wherein the solar cell module is connected to the metal substrate.
6. The metal substrate is made of any one of aluminum, stainless steel, steel material, and cladding materials thereof,
   6. The solar cell module according to claim 1, wherein the insulating layer is made of an oxide film, a nitride film, or an oxynitride film of any one of aluminum, silicon, titanium, and iron.
7. The photoelectric conversion layer includes at least one group Ib element selected from the group consisting of Cu and Ag; at least one group IIIb element selected from the group consisting of Al, Ga and In; and S, Se, 7. The solar cell module according to claim 1, comprising at least one compound semiconductor composed of at least one VIb group element selected from the group consisting of Te and Te.
8. A solar cell submodule comprising at least a metal substrate comprising an insulating layer on the surface, a solar cell unit comprising positive and negative electrodes on the insulating layer, and connected to the positive and negative electrodes, respectively. , A method for manufacturing a solar cell module comprising a pair of lead wires for taking out the output from the solar cell unit to the outside,
   One of the pair of lead wires is connected to the metal substrate;
   By performing ultrasonic soldering from one of the positive electrode and the negative electrode, a micro crack is formed from the one electrode through the insulating layer directly below the electrode to reach the metal substrate. By infiltrating the solder material in the inside to form an electrical connection portion between the one electrode and the metal substrate,
   The method of manufacturing a solar cell module, wherein the one lead wire is connected to the one electrode through the electrical connection portion.
9. The one lead wire is ultrasonically soldered to a region of the surface of the insulating layer where the solar cell portion is not formed, thereby passing through the insulating layer in the region to reach the metal substrate. 9. The method for manufacturing a solar cell module according to claim 8, wherein a crack is formed and a solder material is infiltrated into the micro crack to be connected to the metal substrate.
10. As the metal substrate, using a back side provided with a back side insulating layer,
    The one lead wire is ultrasonically soldered to the surface of the back-side insulating layer to form a microcrack that penetrates the back-side insulating layer and reaches the metal substrate. The method for manufacturing a solar cell module according to claim 8, wherein a solder material is infiltrated and connected to the metal substrate.

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