JP2007056345A - Electrode pattern forming method, and photoelectric cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode pattern forming method excellent in mass productivity. <P>SOLUTION: In the electrode pattern forming method, a hot-melt layer 8 is covered by a covering layer 4 consisting of a metallic material, and an electrode pattern 22a is formed on a substrate 20 by using a main electrode forming mask 10a having an aperture 12a for forming a main electrode penetrating face and back surfaces. The method comprises a step of heat-bonding the main electrode forming mask 10a on a surface of the substrate via a hot-melt layer 8, a step of forming the main electrode pattern 22a on the substrate 20 by performing the physical vapor deposition of a conductive vapor deposition material via the aperture 12a for forming the main electrode, and a step of peeling the main electrode forming mask. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrode pattern forming method and a photovoltaic module.

  A substrate on which an electrode pattern is formed is widely used in photovoltaic cells, displays, and the like that convert light energy such as sunlight into electrical energy. For example, in the case of a photovoltaic cell such as an amorphous silicon photovoltaic cell or a dye-sensitized photovoltaic cell, a photoelectric conversion layer is provided between a pair of substrates each formed with an electrode pattern made of a transparent conductive film or the like.

  As a method for forming an electrode pattern on a substrate, a photolithography method has been conventionally known in which a photosensitive resin is applied to the surface of a substrate, then ultraviolet rays are irradiated through a photomask, and etching is performed using a chemical solution. (For example, Patent Document 1).

However, when the electrode pattern is formed by photolithography, depending on the material of the substrate, there is a risk of being damaged by the acid or alkali of the chemical solution, and when the electrode pattern is continuously formed, it is discarded. The amount of chemicals has increased, causing environmental pollution problems and unsuitable for mass production.
JP-A-8-330692

  Then, this invention aims at provision of the formation method and photovoltaic module of an electrode pattern which are excellent in mass productivity.

  The object of the present invention is to form an electrode pattern on a substrate using a main electrode formation mask in which a hot melt layer is covered with a coating layer made of a metal material and has openings for forming a main electrode penetrating the front and back surfaces. A method in which the main electrode forming mask is thermocompression bonded to the surface of the substrate through the hot melt layer, and physical vapor deposition of a conductive vapor deposition material is performed through the main electrode forming opening. Thus, this is achieved by an electrode pattern forming method comprising a step of forming a main electrode pattern on the substrate and a step of peeling off the main electrode formation mask.

  Further, the object of the present invention is achieved by a photovoltaic module in which a photoelectric conversion layer and a counter electrode are laminated on a main electrode pattern formed on a substrate by the above electrode pattern forming method.

  ADVANTAGE OF THE INVENTION According to this invention, the formation method and photovoltaic module of an electrode pattern which are excellent in mass productivity can be provided.

Hereinafter, a method for manufacturing a photovoltaic cell module using an electrode pattern forming method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1. Formation of Front Electrode Film A method for producing the front electrode film constituting the photovoltaic module will be described with reference to the process cross-sectional views shown in FIGS. First, as shown in FIG. 1A, a base film 6 having a pressure-sensitive adhesive layer 2 formed on one surface and a coating layer 4 formed on the other surface is prepared. The melt layer 8 is bonded to form a laminate 10 as shown in FIG.

  The pressure-sensitive adhesive layer 2 can use a heat-resistant strong pressure-sensitive adhesive such as an acrylic resin or a urethane resin. Although the thickness of the adhesive layer 2 is not specifically limited, For example, it is 1-40 micrometers.

  The coating layer 4 is made of a metal material such as aluminum or copper, and protects the surface of the base film 6 at the time of a subsequent cleaning process. The thickness of the coating layer 4 is not particularly limited, but is, for example, 1 to 50 μm.

  The base film 6 is made of a hard film formed of polypropylene, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, or the like, and the thickness is preferably about 20 to 100 μm.

  As the hot melt layer 8, for example, a known layer in which a tackifier such as rosin or terpene is added to a polyester resin, a polyamide resin, an EVA resin, a polyolefin resin, or the like can be used.

  Next, the laminated body 10 is die-cut to form an opening 12a as shown in FIG. The opening 12a is an opening for forming a main electrode, and has a shape corresponding to a main electrode pattern formed on the substrate 20 described later. In this way, the main electrode forming mask 10a having the main electrode forming opening 12a is obtained.

  Next, as shown in FIG. 1 (d), the main electrode formation mask 10 a is bonded onto the substrate 20. Examples of the substrate 20 include resin films having high heat resistance and insulation such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and glass substrates. In addition, polymethyl methacrylate, polycarbonate, polystyrene, Examples thereof include polyethylene sulfide, polyethersulfone, polyolefin, triacetyl cellulose, and acrylic resin.

  The main electrode forming mask 10a can be bonded to the substrate 20 by thermocompression using a thermocompression roller or the like, but the adhesive strength is not increased too much by making the hot melt layer 8 in a semi-molten state. It is preferable to make adjustment so that the hot-melt layer 8 and the substrate 20 can be easily separated.

  Next, the upper surface side of the substrate 20 is subjected to corona discharge treatment, excimer treatment, etc. to clean the portion exposed from the opening 12a on the substrate 20, and then the physical properties of the conductive vapor deposition material through the opening 12a. By performing general vapor deposition, a main electrode pattern 22a is formed on the substrate 20 as shown in FIG. Then, as shown in FIG. 1 (f), the main electrode formation mask 10 a is peeled between the hot melt layer 8 and the substrate 20.

  Examples of the physical vapor deposition method for forming the main electrode pattern 22a include vacuum vapor deposition, sputtering, and ion plating. Moreover, as a conductive vapor deposition material, transparent materials, such as ITO (indium tin oxide), FTO (fluorine dope tin oxide), and ATO (antimony dope tin oxide), can be illustrated. The pattern shape of the main electrode pattern 22a is not particularly limited, and various shapes such as a strip shape, a rectangular shape, and a linear shape are possible, and the main electrode pattern 22a can be configured by a plurality of pattern portions.

  Thus, after forming the main electrode pattern 22a on the substrate 20, the auxiliary electrode pattern 22b is formed on the same substrate 20 using the auxiliary electrode formation mask 10b. The auxiliary electrode pattern 22b can be created in the same procedure as the method of creating the main electrode pattern 22a described above, and an opening for forming an auxiliary electrode is formed on the stacked body 10 instead of the opening 12a for forming the main electrode. It is obtained by forming the portion 12b.

  As shown in FIG. 2A, after the auxiliary electrode forming mask 10b is aligned with the substrate 20 so that the opening 12b is disposed at a desired position with respect to the main electrode pattern 22a on the substrate 20. The hot melt layer 8 is temporarily bonded to the substrate 20 in the same manner as described above. Then, the auxiliary electrode pattern 22b is formed along the main electrode pattern 22a on the substrate 20, as shown in FIG. 2B, by performing physical vapor deposition of the conductive vapor deposition material through the opening 12b. . The material of the auxiliary electrode pattern 22b is preferably lower in resistance than the main electrode pattern 22a, and examples thereof include metal materials such as platinum, gold, copper, silver, and chromium-copper-chromium.

  In the present embodiment, the auxiliary electrode pattern 22b is linearly formed along both longitudinal edges of the main electrode pattern 22a. However, as long as the auxiliary electrode pattern 22b is formed along the main electrode pattern 22a, the auxiliary electrode pattern 22b is formed. The position and shape of 22b are not particularly limited. Thereafter, the auxiliary electrode forming mask 10b is peeled off, whereby the front electrode film 30 in which the electrode pattern 22 including the main electrode pattern 22a and the auxiliary electrode pattern 22b is formed on the substrate 20 as shown in FIG. Is obtained.

  In the present embodiment, the auxiliary electrode pattern 22b is formed after the main electrode pattern 22a is formed, but the main electrode pattern 22a may be formed after the auxiliary electrode pattern 22b is formed first.

  That is, as shown in FIG. 12A, after the auxiliary electrode formation mask 10b is bonded onto the substrate 20 made of an electrode film or the like and the auxiliary electrode pattern 22b is formed through the opening 12b, The auxiliary electrode forming mask 10b is peeled off as shown in FIG. Then, as shown in FIG. 12C, the main electrode forming mask 10a is bonded onto the substrate 20 on which the auxiliary electrode pattern 22b is formed, and cleaning such as corona discharge treatment is performed on the substrate 20 through the opening 12a. After the processing, the main electrode pattern 22a is formed through the opening 12a. In the present embodiment, the auxiliary electrode pattern 22b is formed along the outer peripheral edge of the main electrode pattern 22a, and the main electrode pattern 22a is formed so as to be filled therebetween.

  Next, a semiconductor electrode material is vapor-deposited through the opening 12a, and as shown in FIG. 12D, a semiconductor layer 34a is deposited on the upper surface of the main electrode pattern 22a, and then a semiconductor electrode is formed on the upper surface of the semiconductor layer 34a. By applying the material with a squeegee or the like, a semiconductor electrode 34 is formed as shown in FIG. Thereafter, the main electrode formation mask 10a is peeled off.

  Thus, by forming the main electrode pattern 22a after the formation of the auxiliary electrode pattern 22b, not only the main electrode pattern 22a but also the semiconductor electrode 34 can be formed using the main electrode formation mask 10a. The main electrode formation mask 10a can also be used as a semiconductor electrode formation mask to increase manufacturing efficiency. The formation of the semiconductor electrode 34 will be described in detail later.

  The main electrode forming mask 10a can be peeled between the hot melt layer 8 and the substrate 20, but the hot melt layer 8 and the base film 6 can be formed by forming the adhesive layer 2 from a weak adhesive. The front electrode film 30 in which the hot melt layer 8 remains can be produced as shown in FIG.

  The auxiliary electrode pattern 22 b is not always necessary, and only the main electrode pattern 22 a may be provided on the substrate 20. However, when the main electrode pattern 22a is made of, for example, ITO, the power loss increases as the length in the longitudinal direction increases. In this case, the auxiliary electrode pattern along the longitudinal direction of the main electrode pattern 22a. It is preferable to provide 22b. In this case, the auxiliary electrode pattern 22b is formed of a material having a resistance lower than that of the main electrode pattern 22a, so that the surface resistance value of the auxiliary electrode pattern 22b becomes smaller than the surface resistance value of the main electrode pattern 22a. Set to. More specifically, when the surface resistance value of the main electrode pattern 22a in use is set to 1, the surface resistance value of the auxiliary electrode pattern 22b is preferably 0.1 or less, for example, the main electrode pattern made of ITO. Whereas the surface resistance value of the electrode pattern 22a is 100Ω / □, the surface resistance value of the auxiliary electrode pattern 22b made of platinum can be 3Ω / □.

  Formation of the electrode pattern 22 (the main electrode pattern 22a and the auxiliary electrode pattern 22b) on the substrate 20 can be continuously performed as follows, for example. First, as shown in a perspective view in FIG. 3A, alignment holes H are formed in both side edges of the film-like substrate 20 and the laminated body 10, and an opening 12 a is formed in the laminated body 10. By providing a plurality at regular intervals along the longitudinal direction, the main electrode formation mask 10a is formed.

  Then, the substrate 20 and the main electrode formation mask 10a are transported by transport rollers 42 and 44, respectively, and as shown in FIG. By supplying, the main electrode formation mask 10 a is thermocompression bonded to the substrate 20. The thermocompression bonding conditions by the thermocompression rolls 46 and 46 are preferably set as appropriate so that the hot melt layer 8 is temporarily bonded in a semi-molten state. For example, the roll surface temperature is 120 ° C. and the applied pressure is 0. 0.5 MPa, pressurization time is 2 seconds.

  The thermocompression-bonding rolls 46, 46 are provided with engaging portions S on both sides, and the substrate 20 and the main electrode are formed when the alignment holes H of the substrate 20 and the main electrode forming mask 10 a are engaged with the engaging portions S. Positioning in the width direction and the longitudinal direction of the mask 10a is performed. The alignment of the substrate 20 and the main electrode formation mask 10a is not limited to such a method, and for example, the alignment can be performed by aligning alignment marks provided in place of the alignment hole H and the engaging portion S. Is possible. Further, before passing the thermocompression-bonding rolls 46, 46, the substrate 20 and the main electrode forming mask 10a may be aligned by a cold roll having sprocket holes. Can be made easier.

  The substrate 20 is wound around a winding roll (not shown) in a state where the main electrode forming mask 10a is temporarily bonded, and then loaded into a physical vapor deposition apparatus such as a vacuum vapor deposition apparatus. And after extending | stretching again in a physical vapor deposition apparatus and performing physical vapor deposition through the opening part 12a, as shown in FIG.3 (c), the main electrode formation mask 10a is peeled by the adhesion roll 48, The main electrode pattern 22a remains.

  Next, as shown in FIG. 3D, the auxiliary electrode forming mask 10b is laminated on the surface of the substrate 20 on which the main electrode pattern 22a is formed by a transport roll (not shown), and a pair of thermocompression-bonding rolls. By supplying between 52 and 52, the auxiliary electrode forming mask 10b is temporarily bonded to the substrate 20. Thereafter, the substrate 20 is transported to a physical vapor deposition apparatus in the same manner as described above, and after physical vapor deposition is performed through the opening 12b, the auxiliary electrode formation mask 10b is peeled off and the auxiliary electrode pattern remains.

  As described above, according to the electrode pattern forming method of the present embodiment, the electrode pattern can be continuously formed without using a water-soluble chemical solution or an organic solvent as in the prior art, and the burden on the environment is reduced. However, mass production can be made possible.

  Further, in the main electrode forming mask 10a (or auxiliary electrode forming mask 10b), the hot melt layer is covered with a coating layer made of a metal material, so that the hot melt layer is heated by the heat during physical vapor deposition of the conductive material. 8 can be prevented from adhering to the substrate 20, and the main electrode formation mask 10 a (or the auxiliary electrode formation mask 10 b) can be easily peeled from the substrate 20. Such an effect is particularly remarkable when the base film 6 is interposed between the coating layer 4 and the hot melt layer 8 as in the present embodiment.

  The configuration of the main electrode formation mask 10a (or the auxiliary electrode formation mask 10b) is not necessarily limited to that of the present embodiment, and may be other configurations as long as the hot melt layer 8 is covered with the coating layer 4. For example, the coating layer 4 may be directly formed on the surface of the hot melt layer 8.

The electrode pattern forming method described above is suitable as a method for forming an electrode pattern of a dye-sensitized photovoltaic cell, as will be described later, but is not limited to this, and the electrode pattern used for other types of photovoltaic cells and It can also be used as a method for forming electrode patterns used in other devices such as liquid crystal display devices and EL light emitting devices.

2. Formation of Semiconductor Electrode (Photoelectric Conversion Layer) A semiconductor electrode to be a photoelectric conversion layer is formed on the substrate 20 on which the electrode pattern 22 is formed as follows. First, a semiconductor electrode formation mask 30a having an opening 32a having the same configuration as that of the main electrode formation mask 10a (see FIG. 1C) is prepared. As shown in FIG. The semiconductor electrode forming mask 30a is bonded onto the substrate 20 while aligning with the opening 32a. In the semiconductor electrode formation mask 30a, the same components as those in the main electrode formation mask 10a are denoted by the same reference numerals.

  As for the bonding of the semiconductor electrode forming mask 30a to the substrate 20, it is preferable to use temporary bonding that can be easily peeled between the hot melt layer 8 and the substrate 20, similarly to the bonding of the main electrode forming mask 10a. In this state, the surface of the substrate 20 is subjected to a corona discharge treatment or the like to clean the surface of the electrode pattern 22 exposed from the opening 32a, and then a semiconductor electrode is formed on the electrode pattern 22 as shown in FIG. A first semiconductor layer 34a made of a material is formed by physical vapor deposition. Next, as shown in FIG. 4C, a semiconductor electrode material is applied by a squeegee or the like, and a second semiconductor layer 34b is deposited on the first semiconductor layer 34a. The first semiconductor layer 34 a is not always necessary, and the second semiconductor layer 34 b may be directly formed on the electrode pattern 22. Examples of the semiconductor electrode material include oxides such as zinc, niobium, tin, titanium, indium, tungsten, tantalum, molybdenum, manganese, nickel, and copper, and further gallium phosphide and indium phosphide.

  The first semiconductor layer 34a is a dense film formed by physical vapor deposition, and prevents a photosensitizing dye and an electrolytic solution described later from coming into contact with the electrode pattern 22. On the other hand, the second semiconductor layer 34b is preferably a porous film formed by depositing semiconductor fine particles having a diameter of about 5 nm to 200 nm in order to increase the amount of a photosensitizing dye to be described later. Usually, it is about 0.1 to 20 μm. In addition, after deposition of semiconductor fine particles, a titanium sol or peroxotitanium sol may be applied by hydrolyzable titanium compound, hydrolyzable titanium low condensate, titanium hydroxide, titanium hydroxide low condensate, etc., and after washing with water. If necessary, the second semiconductor layer 34b can be obtained by evaporating water by heating.

  Thereafter, as shown in FIG. 4 (d), the sensitizing dye solution is immersed in the second semiconductor layer 34b, electrophoresed or squeegee-coated, and then dried to dry the semiconductor carrying the photosensitizing dye. An electrode 34 is obtained.

  Conventionally known photosensitizing dyes used for dye sensitization in the semiconductor electrode 34 can be used, for example, ruthenium-tris, ruthenium-bis, osmium-tris, osmium-bis type transition metal complexes, or ruthenium- Cis-diaqua-bipyridyl complexes, or so-called metal chelate complexes such as phthalocyanines and porphyrins, dithiolate complexes, acetylacetonate complexes, and organic dyes such as cyanidin dyes, merocyanine dyes, rhodamine dyes, and oxadiazole derivatives, benzothiazole derivatives, Examples thereof include a coumarin derivative, a stilbene derivative, and an organic compound having an aromatic ring. These dyes have a functional group such as a carboxyl group, a sulfonic acid group, a phosphoric acid group, an amide group, an amino group, a carbonyl group, and a phosphine group so that they are easily chemically adsorbed on the second semiconductor layer 34b. It is preferable. For example, these photosensitizing dyes can be dissolved in an appropriate solvent, and then the dye solution can be adsorbed and supported on the second semiconductor layer 34b.

  Thereafter, the semiconductor electrode formation mask 30a is peeled off, so that the semiconductor electrode 34 remains on the electrode pattern 22 of the substrate 20 as shown in FIG.

  The formation of the semiconductor electrode 34 on the substrate 20 can be performed in the same manner as the formation of the electrode pattern 22. That is, the film-like laminate 10 is drawn out from a roll or the like to form alignment holes and alignment marks on both side edges, and by providing an opening 32a corresponding to the electrode pattern 22, thereby forming the semiconductor electrode forming mask 30a. Form. And after laminating | stacking the semiconductor electrode formation mask 30a on the board | substrate 20, thermocompression bonding, it conveys to coating apparatuses, such as a screen printer and a roll coating machine. The alignment between the substrate 20 and the semiconductor electrode formation mask 30a can be performed using alignment holes or alignment marks.

  Then, after the semiconductor electrode material and the dye solution are sequentially applied onto the substrate 20 in the coating apparatus, the substrate 20 is transported to a drying apparatus and subjected to heat drying. Thereby, the formation of the semiconductor electrode 34 on the substrate 20 is completed. Thereafter, the semiconductor electrode forming mask 30a is peeled off by the adhesive force of the adhesive roll, and the semiconductor electrode 34 remains.

Thus, according to the method for forming a semiconductor electrode of the present embodiment, a semiconductor electrode having high photoelectric conversion efficiency can be formed continuously and efficiently.

3. Formation of Back Electrode Film The back electrode film can be produced by forming a main electrode pattern on the substrate in the same procedure as in the case of the front electrode film 30 described above. As a material used for the main electrode pattern of the back electrode film, in addition to transparent materials such as ITO (indium tin oxide), FTO (fluorine doped tin oxide), ATO (antimony doped tin oxide), gold, silver, copper Metal materials such as platinum and chromium can be exemplified, and a main electrode pattern may be formed by laminating two or more of these materials. For example, the main electrode pattern of the back electrode film can be formed by depositing an ITO film on the substrate through the opening of the main electrode formation mask and further depositing a platinum film through the opening. . Further, before the main electrode pattern made of metal or the like is formed on the substrate, an undercoat film is applied on the substrate and dried, so that the undercoat layer 81 is interposed on the substrate 82 as shown in FIG. Thus, it is possible to form the back electrode film 80 on which the electrode pattern 83 is formed, whereby the adhesion of the electrode pattern 83 can be improved.

  The back electrode film can also be formed using a main electrode forming mask in which a hot melt layer and a coating layer are laminated via an adhesive layer. That is, as shown in FIG. 10A, after the coating layer 4 is bonded to the hot melt layer 8 via the pressure-sensitive adhesive layer 2, as shown in FIG. By forming the portion 12a, the main electrode formation mask 100a can be obtained. In FIG. 10, the same components as those shown in FIG.

  Thereafter, the main electrode forming mask is bonded onto the substrate in the same procedure as the steps shown in FIGS. 1D to 1F, and then the physical vapor deposition of the conductive material is performed to obtain the hot melt layer and the substrate. The main electrode pattern can be formed on the substrate by peeling the main electrode formation mask between the two.

As shown in FIG. 10C, an undercoat layer 81 may be formed on the surface of the substrate 20 to which the main electrode forming mask 100a is bonded by applying an undercoat material in advance and drying it. Further, the hot melt layer 8 and the coating layer 4 can be bonded together by firmly bonding the hot melt layer 8 to the coating layer 4 and firmly bonding the adhesive layer 2 instead of the adhesive layer 2. Yes, as shown in FIG. 11, the main electrode forming mask 101 a can be configured such that the hot melt layer 8 is directly bonded to the coating layer 4.

4). Formation of Wiring Portion Next, a method for forming a wiring portion for establishing conduction between the front electrode film 30 and the back electrode film 80 described above will be described.

  First, as shown to Fig.6 (a), the base film 64 in which the adhesive layer 62 was formed in one side was prepared, the hot-melt layer 66 was bonded together to the adhesive layer 62, and FIG.6 (b). As shown in FIG.

  The pressure-sensitive adhesive layer 62 is easily peelable from the hot melt layer 66, and for example, a heat-resistant fine pressure-sensitive adhesive made of an acrylic resin can be used. What is necessary is just to set the thickness of the adhesive layer 62 in consideration of the thickness of the electrolyte layer mentioned later, for example, it is 1-40 micrometers.

  The base film 64 is made of a hard film formed of polypropylene, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, fluororesin, or the like, and the thickness is preferably about 20 to 100 μm.

  As the hot melt layer 66, for example, a known layer in which a tackifier such as rosin or terpene is added to a polyester resin, a polyamide resin, an EVA resin, a polyolefin resin, or the like can be used.

  Next, as shown in FIG. 6C, only the hot melt layer 66 is cut out (half-cut) to form the electrolytic solution containing portion 68a and the wiring portion forming hole 68b penetrating the entire laminate. Then, a bonding mask 69 is formed. At this time, the electrolytic solution flow path for supplying the electrolytic solution to the electrolytic solution storage portion 68a is also formed by half-punching to remove only the hot melt layer 66.

  Then, as shown in FIG. 6D, the bonding mask 69 is disposed on the substrate 82 of the back electrode film 80 so that the wiring portion forming hole 68b and the electrode pattern 83 are aligned. Then, the hot melt layer 66 is thermocompression bonded to the substrate 82 using a thermocompression roller or the like. In this thermocompression bonding, it is preferable that the hot melt layer 66 is sufficiently melted and firmly adhered to the substrate 82. Specifically, the adhesive strength between the hot melt layer 66 and the substrate 82 is preferably 2 N / cm or more. On the other hand, it is preferable that the adhesive layer 62 and the hot melt layer 66 can be easily peeled as described above, and the adhesive strength is lower than the adhesive strength between the hot melt layer 66 and the substrate 82. Is preferred. Specifically, the adhesive strength between the pressure-sensitive adhesive layer 62 and the hot melt layer 66 is preferably 0.01 to 0.2 N / cm.

  The steps up to here are performed by unwinding the film-like laminate 68 from a roll or the like to form alignment holes and alignment marks on both side edges, and forming an electrolytic solution containing portion 68a and a wiring portion forming hole 68b. After the bonding mask 69 is formed, it can be continuously formed by placing it on the substrate 82 and thermocompression bonding.

  Thereafter, the conductive paste for wiring part formation described above is applied to the bonding mask 69 by squeegee to fill the wiring part forming hole 68b with the conductive paste 61a as shown in FIG. To do. Then, the bonding mask 69 is peeled off between the pressure-sensitive adhesive layer 62 and the hot melt layer 66 by a peeling roller or the like, and the base film 64 is removed while the hot melt layer is removed as shown in FIG. Layer 66 remains.

  The conductive paste 61a is formed by stirring and mixing a solder alloy powder with a resin solution. Solder alloys include Sn / Bi, Sn / Bi / Pb, Sn / Bi / Zn, Bi / Pb, Sn / In, Sn / Bi / Pb, Sn / Bi / In, Sn / Bi / Pb / In and other low melting points The solder alloy powder can be preferably exemplified, and a desired melting point can be obtained by appropriately adjusting the composition ratio. The average particle size of the solder alloy powder can be exemplified by about 0.01 to 50 μm.

  More specifically, the liquidus temperature of the solder alloy powder is preferably lower than the heat resistant limit temperature of the substrate 20, and more preferably at most 150 ° C. Here, the “heat-resistant limit temperature” refers to the maximum temperature at which material deterioration and deterioration can be prevented, for example, PET: about 130 ° C., methyl methacrylate acrylic resin: about 70 ° C., silicone resin: about 180 ° C. . On the other hand, when considering the use at high temperatures outdoors, the liquidus temperature of the solder alloy powder is preferably 60 ° C. or higher, and more preferably 70 ° C. or higher. Table 1 shows the relationship between the composition ratio, the solidus temperature, and the liquidus temperature.

樹脂溶液は、各種有機溶媒、水、或いはこれらの２種以上の混合液からなる溶媒に、アクリル樹脂、アクリルウレタン樹脂、ウレタン樹脂、ポリエステル樹脂、フェノール樹脂などの可撓性および密着性が良好な熱硬化性樹脂を溶解させたものを、好ましく用いることができる。溶解される樹脂は、半田合金粉末の加熱溶融時において熱分解が生じない程度の耐熱性を有することが好ましい。

The resin solution has good flexibility and adhesion such as acrylic resin, acrylic urethane resin, urethane resin, polyester resin, and phenol resin in various organic solvents, water, or a solvent composed of a mixture of two or more of these. What melt | dissolved the thermosetting resin can be used preferably. It is preferable that the resin to be dissolved has a heat resistance that does not cause thermal decomposition when the solder alloy powder is heated and melted.

  Since the proportion of the volume of the solder alloy powder in the volume of the resin solution (volume fraction) is too large, it is difficult to ensure adhesion to the substrate, whereas if it is too small, it is difficult to ensure good conductivity. It is preferable that it is 50 to 90%, and 70 to 85% is more preferable.

  Next, as shown in FIG. 7C, the front electrode film 30 with the hot melt layer 8 (see FIG. 12F) is connected to the conductive paste 61a with the electrode pattern 22 on the substrate 20. Then, alignment is performed so that the semiconductor electrode 34 on the electrode pattern 22 is accommodated in the electrolyte accommodating portion 68a, and the hot melt layers 8 and 66 are bonded together. Thereafter, the hot melt layers 8 and 66 are heated and melted by using a thermocompression roller or the like, and the front electrode film 30 and the back electrode film 80 are firmly adhered.

  In actual manufacturing, as shown in FIG. 8, a plurality of photovoltaic cells having semiconductor electrodes 34 are formed between the electrode patterns 22 and 83, and the adjacent semiconductor electrodes 34 and 34 are connected to the electrode patterns 22 and 83 and the conductive paste. It is preferable to be configured to be electrically connected in series (or in parallel) via 61a. Due to the heating of the hot melt layer 66, the conductive paste 61a filled in the wiring portion forming hole 68b melts the resin and comes into close contact with the front electrode film 30 and the back electrode film 80, and the solder alloy powder melts. As a result of the connection between the electrode patterns 22 and 83 being able to be conducted, reliable conduction can be obtained between the front electrode film 30 and the back electrode film 80. The heating temperature and heating time of the hot melt layer 66 may be appropriately set in consideration of the material of the hot melt layer 66 and the conductive paste 61a, and are, for example, about 120 to 150 ° C. and about 10 to 15 minutes. .

  Thus, according to the method for forming a wiring portion of the present embodiment, the manufacturing efficiency can be increased by simultaneously forming the wiring portion in the step of bonding the front electrode film 30 and the back electrode film 80 together. .

  In the present embodiment, a resin film is used as the base film 64, but a film of another material such as a metal film can also be used. Further, the pressure-sensitive adhesive layer 62 interposed between the base film 64 and the hot melt layer 66 is not always necessary. When the base film 64 can be easily peeled from the hot melt layer 66, the hot melt layer 66 is not necessary. The base film 64 may be directly bonded to the substrate.

  The above description is an example for achieving three-dimensional conduction between the front electrode film 30 and the back electrode film 80. In the front electrode film 30 or the back electrode film 80, the electrode patterns 22 and 83 are configured. In order to connect each electrode part in series or in parallel, or to form an electrical connection part to the electrode patterns 22 and 83, the above-described conductivity is provided on the substrate 20 or 82 of the front electrode film 30 or the back electrode film 80. It is also possible to form a wiring portion made of a conductive paste. In this case, the wiring part is formed by applying a conductive paste on the substrate with a squeegee or the like through a wiring part forming mask having an opening of a predetermined shape.

  Similar to the main electrode formation mask 10a described above, the wiring portion formation mask has a configuration in which a hot melt layer is formed on one surface of a base film made of PET or the like via an adhesive layer 2 made of a strong adhesive. The hot melt layer can be temporarily bonded in a peelable manner by thermocompression bonding in a semi-molten state using a thermocompression-bonding roll or the like. The surface of the base film may be coated with a heat resistant film as necessary. In addition to this, the wiring portion forming mask may have a structure with a weak adhesive layer whose adhesive strength is adjusted on one surface of the base film, and can be crimped to the substrate by a crimping roll. Furthermore, it can also be set as the structure which laminated | stacked the wiring part formation mask with a hot-melt layer mentioned above on such a wiring part formation mask with a weak adhesion layer.

According to such a method for forming a wiring portion, a wiring portion having good adhesion and conductivity can be efficiently manufactured.

5. Formation of Electrolyte Layer Next, an electrolyte layer is formed between the front electrode film 30 and the back electrode film 80. The hot melt layer 66 remaining on the substrate 82 is formed with an electrolyte flow path, which communicates the electrolyte container 68a with the outside.

  As shown in FIG. 9 (a), by suctioning on the OUT side of the electrolyte channel, the electrolyte is supplied from the IN side of the electrolyte channel, and the electrolyte is injected into the electrolyte container 68a. An electrolyte layer 90 is formed. Examples of the electrolytic solution include those obtained by dissolving an electrolyte such as iodine / iodide, bromine / bromide, and a transition metal complex in a solvent such as acetonitrile or ethylene carbonate or an ionic liquid such as an imidazolium salt. In addition, the flow of the electrolytic solution in FIG. 9A is schematically shown, and actually the electrolytic solution flows in a direction penetrating the drawing.

In addition to injecting the above-described electrolyte solution, the electrolyte layer is prepared by previously applying a gel electrolyte, a molten salt electrolyte, a solid electrolyte, or the like to the front electrode film 30 or the back electrode film 80, and then the front electrode film 30 and the back electrode film 80. Can also be formed.

6). Ultrasonic welding After the formation of the electrolyte layer 90, as shown in FIG. 9 (b), the front electrode film 30 and the back electrode film 80 are ultrasonically welded so as to surround the entire electrolyte container 68a. A portion 91 is formed, and the electrolyte solution of the electrolyte layer 90 is sealed. Then, by removing the outside of the sealing portion 91, as shown in FIG. 9C, a photovoltaic module in which the photoelectric conversion layer and the counter electrode are sequentially stacked on the electrode pattern is completed. The output from the photovoltaic module can be taken out from connection terminal holes 92 and 92 formed at two corners.

  Ultrasonic welding can be performed using an ultrasonic welding apparatus including a horn to which vibration energy is transmitted from a vibrator and a pedestal on which an object to be welded is placed. A protrusion (energy director) for concentrating vibration energy is provided on the upper surface of the pedestal, and the front electrode film 30 and the back electrode film 80 are pressed between the horn and the pedestal so By applying sonic vibration, frictional heat is generated, the resin is melted, and both are bonded. In order to reliably seal the electrolyte layer 90 by ultrasonic welding, it is preferable that the substrates 20 and 82 of the front electrode film 30 and the back electrode film 80 and the hot melt layer 66 are made of the same material. Here, the “equivalent material” refers to a material having substantially the same physical property values such as a melting temperature and a thermal expansion coefficient in addition to the case where the materials are completely the same. As a specific material, at least one selected from polyethylene terephthalate (PET), silicon resin, fluorine resin, and acrylic resin is preferable, and polyethylene terephthalate is particularly preferable.

It is process sectional drawing which shows an example of the process of forming a main electrode pattern on the board | substrate of a front electrode film. It is process sectional drawing which shows an example of the process of forming an auxiliary electrode pattern on the board | substrate of a front electrode film. It is a process perspective view which shows an example of the process of forming the said main electrode pattern and an auxiliary electrode pattern continuously on a board | substrate. It is process sectional drawing which shows an example of the process of forming a semiconductor electrode. It is sectional drawing which shows an example of a back electrode film. It is process sectional drawing which shows an example of the pre-process for forming a wiring part and an electrolyte layer. It is process sectional drawing which shows an example of the process of forming a wiring part and an electrolyte layer. It is sectional drawing of the photovoltaic cell module which concerns on one Embodiment of this invention. It is process sectional drawing which shows an example of formation of an electrolyte layer, and a sealing process. It is process sectional drawing which shows the other method of forming a main electrode pattern using a main electrode formation mask. It is sectional drawing of the main electrode formation mask used for the further another method of forming a main electrode formation pattern. It is process sectional drawing which shows the other method of forming an electrode pattern.

Explanation of symbols

2 Adhesive Layer 4 Covering Layer 6 Base Film 8 Hot Melt Layer 10 Laminate 10a Main Electrode Formation Mask 12a Opening 20 Substrate 22 Electrode Pattern 22a Main Electrode Pattern 22b Auxiliary Electrode Pattern 30 Front Electrode Film
30a Semiconductor electrode formation mask 32a Opening 34 Semiconductor electrode 62 Adhesive layer 64 Base film 66 Hot melt layer 68 Laminate 68a Electrolyte container 68b Wiring part formation hole 69 Mask for bonding 80 Back electrode film 90 Electrolyte layer 91 Sealing Stop

Claims (5)

A method of forming an electrode pattern on a substrate by using a main electrode forming mask having a main electrode forming opening having a hot electrode layer covered with a coating layer made of a metal material and penetrating front and back surfaces,
Thermocompression bonding the main electrode formation mask to the surface of the substrate through the hot melt layer;
Forming a main electrode pattern on the substrate by performing physical vapor deposition of a conductive vapor deposition material through the opening for forming the main electrode;
And a step of peeling off the main electrode forming mask. The said main electrode formation mask is formed by laminating | stacking the said hot-melt layer on one side of a base film through an adhesive layer, and laminating | stacking the said coating layer on the other side of the said base film. A method for forming an electrode pattern according to the above. After the step of peeling the main electrode formation mask,
A step of thermocompression bonding an auxiliary electrode forming mask having an auxiliary electrode forming opening that is covered with a coating layer made of a metal material and penetrating the front and back surfaces to the surface of the substrate through the hotmelt layer; ,
Forming an auxiliary electrode pattern along the main electrode pattern by performing physical vapor deposition of a conductive vapor deposition material through the auxiliary electrode forming opening;
Peeling the auxiliary electrode forming mask between the hot melt layer and the substrate,
The electrode pattern forming method according to claim 1, wherein the auxiliary electrode pattern is formed so that a surface resistance value is smaller than that of the main electrode pattern. Before the step of thermocompression bonding the main electrode formation mask to the surface of the substrate,
A step of thermocompression bonding an auxiliary electrode forming mask having an auxiliary electrode forming opening that is covered with a coating layer made of a metal material and penetrating the front and back surfaces to the surface of the substrate through the hotmelt layer; ,
Forming an auxiliary electrode pattern by performing physical vapor deposition of a conductive vapor deposition material through the auxiliary electrode forming opening;
Peeling the auxiliary electrode forming mask between the hot melt layer and the substrate,
The electrode pattern forming method according to claim 1, wherein the auxiliary electrode pattern is formed so that a surface resistance value is smaller than that of the main electrode pattern.

A photovoltaic module in which a photoelectric conversion layer and a counter electrode are sequentially laminated on a main electrode pattern formed on a substrate by the electrode pattern forming method according to claim 1.

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