JPH07321351A - Electrode structure of photovoltaic element and manufacture - Google Patents

Abstract

PURPOSE:To simplify connecting step by applying conductive adhesive on the whole length of metal wire for the connection of a collecting electrode with an output electrode and connecting them by thermocompression bonding. CONSTITUTION:An etching line 103 is formed on a surface of a photovoltaic element 101 and to insulate securely between a surface electrode and a lower part electrode, an insulating polyimide tape 104 is stuck on a part a photovoltaic region 102 and an exposing surface of a substrate adjoin. A copper foil 106, that is a conductor to extend the surface electrode, is fixed with a double-sided adhesive tape 105 on the polyimide insulating tape 104. A wire 107 is formed applying conductive adhesive on it and drying it beforehand. Then a photovoltaic element 101 is transferred into a pressing machine, and the wire 107 is laid out and fixed with the copper foil 106 by thermopressing with the pressing machine. With this, steps of soot application and hardening of conductive adhesive are omitted and work procedures are simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode structure of a photovoltaic element used for a solar cell and the like, and a manufacturing method thereof.

[0002]

In recent years, and global warming due to the increase in the greenhouse effect that is CO ₂ becomes a problem, demand for clean sources of energy development that do not emit CO _2, has been increasingly.

In nuclear power generation, which is one of the energy sources that does not cause global warming, the problem of radioactive waste has not been solved, and a safer and cleaner energy source is desired.

Among the clean energy sources that are expected in the future, solar cells have received a great deal of attention because of their cleanliness, safety and ease of handling.

Among various solar cells, the amorphous silicon solar cell has a conversion efficiency which is lower than that of a crystalline solar cell, but it is easy to make a large area and has a large light absorption coefficient so that it can operate as a thin film. This is one of the promising solar cells for the future because it has excellent features not found in crystalline solar cells.

FIG. 5 is a schematic view of a conventional photovoltaic element module, that is, a solar cell module. Figure 5 (a)
Is a step of forming a collecting electrode, and FIG. 5 (b) is FIG. 5 (a).
3 is a cross-sectional view of the XX 'portion in FIG.

In the solar cell element 500 shown in FIG. 5, the lower electrode layer 502 is formed on the surface of the substrate 501, and the lower electrode layer 50 is formed.
The semiconductor layer 503 was formed on the surface of No. 2 and the upper electrode layer 504 was sequentially formed on the surface of the semiconductor layer 503.

In these solar cell elements, in order to completely electrically separate the upper electrode layer and the lower electrode layer, a part (505) of the upper electrode layer is removed, and then the surface of the upper electrode layer is removed. Current collecting electrode 5 which is a collecting electrode of the upper electrode 504
06 is produced (FIG. 5A-). This collector electrode 5
As a method for producing 06, a method in which a conductive paste material is attached to the electrode formation surface by screen printing and the material is heated and hardened is generally used. Currently, with this method, the line width is 100 to 150 μm and the thickness is 10 to 20 μm.
m products have reached the mass production level. There are a wide variety of conductive paste materials, and for amorphous silicon solar cells that generally dislike high-temperature treatment, a polymer paste in which silver or copper fine particles are monodispersed in a curable resin such as polyester, epoxy, or phenol is often used. Used.

Next, a bus bar electrode 507, which is a further collecting electrode of the collecting electrode 506, is placed on the collecting electrode 506 (FIG. 5 (a)-). After that, the intersection of the collector electrode 506 and the bus bar electrode 507 is covered with the conductive adhesive 50.
After being applied in spots at No. 8, it is cured in a hot air drying oven (FIG. 5 (a)-). In this way, by connecting the current collecting electrode 506 and the bus bar electrode 507 while electrically maintaining conductivity, a lead electrode from the upper electrode layer 504 is produced.

An insulating tape 509 is provided between the end portion of the solar cell element 500 and the bus bar electrode 507 in order to ensure the electrical separation between the bus bar electrode 507 and the base body.

[0011]

In the manufacturing method shown in the prior art, the following three steps are required after forming the collector electrode.

The step of aligning the bus bar electrode with a predetermined position.

A step of applying a conductive adhesive in spots at predetermined positions while the bus bar electrodes are fixed.

A conductive adhesive is applied to a hot air drying oven or IR.
The process of heating and curing in an oven.

These processes have a problem that it is difficult to make a mass production line because the number of works is long and the work time is long.

In the case as shown in FIG. 5, that is, in the case where the area of the photovoltaic element is small and the number of collecting electrodes is small, there are few spot-shaped coating portions, so there is no problem. However, when manufacturing a large-area photovoltaic element, the number of current collecting electrodes is considerably large, and the number of bus bar electrodes is not limited to one, and it becomes necessary to use several. In such a case, the number of locations requiring electrical connection increases, and the working time increases proportionately, which is not preferable from the viewpoint of productivity.

An object of the present invention is to establish a simpler connecting process than the conventional one, while maintaining the electrical characteristics at the same level as in the case of using the conventional conductive adhesive in connecting the collecting electrode and the take-out electrode. Therefore, it is to provide an electrode structure of a photovoltaic element that can be easily mass-produced in a mass production line, and a manufacturing method thereof.

[0018]

The electrode structure of a photovoltaic element according to the present invention is a photovoltaic element that generates an electromotive force due to sunlight, and the photovoltaic element on the effective surface of the photovoltaic element. At least a linear metal body arranged to collect electric power generated from the element, and a conductor for collecting electric power from the linear metal body and leading the electric power out of the photovoltaic element. In the electrode structure of the photovoltaic element, the linear metal body and the conductor are fixed by using a conductive adhesive previously applied to the linear metal body over the entire length. .

The method for manufacturing the electrode structure of a photovoltaic element according to the present invention is a photovoltaic element that generates an electromotive force by sunlight, and a photovoltaic element that is located on the effective surface of the photovoltaic element and that is generated from the photovoltaic element. Which has at least a linear metal body arranged to collect the electric power to be collected and a conductor for collecting the electric power from the linear metal body and leading the electric power to the outside of the photovoltaic element. In the method for manufacturing an electrode structure of an element, a step of previously applying the conductive adhesive to the linear metal body over the entire length, and fixing the linear metal body to the conductor using the conductive adhesive And at least steps.

[0020]

In the present invention, since the conductive adhesive is applied off-line to the surface of the linear metal body used as the collector electrode and dried in advance, these linear metal bodies are prepared on the electrode forming surface. When it is placed and cured at the same time, the conductor for external output can be simultaneously fixed by using the above-mentioned conductive adhesive. As a result, when the conventional collecting electrode and the electrode for external extraction are connected, the spot-shaped application and curing work of the conductive adhesive, which are necessary, can be omitted, so that the working process can be reduced.

Further, since it is possible to manufacture the external extraction electrode in substantially the same time as the time required for manufacturing the conventional collecting electrode (printing and curing of the conductive paste).
The working time can be greatly reduced.

[0022]

Embodiments Embodiments of the present invention will be described below.

(Linear Metal Body) Since the linear metal body used in the present invention is used as a current path portion, the loss due to resistance can be minimized and the volume resistivity is low. Metallic materials are desirable, such as gold, silver,
Copper, nickel, aluminum and the like are preferably used.

The cross-sectional shape of the linear metal body may be circular or rectangular, and is appropriately selected as desired. The diameter of the linear metal body is selected so that the sum of electric resistance loss and shadow loss is minimized. For example, an efficient solar cell using a copper wire with a diameter of 25 μm to 200 μm for an enameled wire is used. Is obtained.

(Conductor) From the same viewpoint as the above-mentioned linear metal body, for example, a metal such as gold, silver, copper, tin, lead or nickel can be used as the conductor used as the electrode for external extraction, The present invention is not limited to this, and a plated metal such as silver-plated copper or solder-plated copper may be used. The shape is not particularly limited, and may be linear or foil.

(Electrically Conductive Adhesive) The necessary condition of the electrically conductive adhesive is such that its specific resistance is a value that can be ignored for collecting the current generated by the solar cell, and the shunt is not generated. Has a certain value. The specific resistance value of the conductive adhesive is, for example, 0.1 Ωcm to 100 Ω.
cm is preferable. This is because shunting tends to occur when the resistance is 0.1 Ωcm or less, and electrical resistance loss increases when the resistance is 100 Ωcm or more. A conductive adhesive having such a resistance value can be obtained by dispersing conductive particles in a polymer resin. Examples of the material of the conductive particles include graphite, carbon black and In
₂ O ₃ , TiO ₂ , SnO ₂ , ITO, ZnO and oxide semiconductor materials obtained by adding a suitable dopant to the above materials are preferably used.

Further, the conductive adhesive must have a function of bonding and fixing the linear metal body to the electrode forming surface of the solar cell and the conductor for taking out to the outside. Further, since the conductive adhesive is provided in contact with the linear metal body,
With the function of preventing the penetration of humidity into the linear metal body,
It is necessary to have a function of preventing metal ion migration from the linear metal body. For the above reasons, a resin having a strong adhesive force and a low moisture permeability is preferably used as the polymer resin. Such resins include thermosetting resins and thermoplastic resins. In the case of a thermosetting resin, for example, epoxy, urethane, butyral, a fluororesin or a resin obtained by modifying these is used. In the case of a thermoplastic resin, acrylic, styrene, etc. are used.

The conductive adhesive is prepared by mixing the conductive particles and the polymer resin in a suitable ratio in order to obtain a desired specific resistance. However, if the amount of conductive particles is too large, the specific resistance decreases, but the amount of resin decreases, so that the adhesive function deteriorates, which is not preferable. Further, when the amount of the resin is increased, the adhesiveness is improved, but the contact between the conductive particles becomes defective and the resistance becomes high, which is a problem. Therefore, the ratio in which the conductive particles are dispersed in the polymer resin is appropriately selected according to each physical property value.

Specifically, the conductive particles are contained in an amount of 5% by volume to 95%.
When the content is about volume%, good specific resistance and good adhesion can be obtained. Regarding the mixing of both, a usual dispersion method such as a three-roll mill or a paint shaker can be used. If desired, a dispersant or a coupling agent may be added to improve the dispersion. During or after the dispersion, the conductive adhesive may be diluted with a suitable solvent for adjusting the viscosity.

As a method of applying the conductive adhesive to the linear metal body, a usual method for forming a film of an enameled wire can be preferably used. For example, the conductive adhesive is diluted with a solvent so as to have an appropriate viscosity, a film is formed on the linear metal body by using a roll coater or the like, and passed through a die to obtain a desired film thickness. Then, by drying with infrared heating or the like, a linear metal body coated with a conductive adhesive is obtained.

The following two methods are generally used as a method for adhering the linear metal body coated with the above-mentioned conductive adhesive to the electrode forming surface of the solar cell and the conductor for taking out to the outside. It In the case of a hot-melt resin, it is usually softened by heat to be bonded, but an appropriate pressure may be applied at the time of bonding. Further, in the case of a thermosetting resin, the curing reaction may not be performed at the time of film formation, only the solvent may be dried, and the resin may be heated at the time of adhesion for curing.

(Photovoltaic Element) The photovoltaic element (FIG. 2) used in the present invention can be suitably applied to an amorphous silicon solar cell which is desired to have flexibility. However, the same configuration can be applied to a solar cell using a single crystal silicon type, a polycrystalline silicon type, or a semiconductor other than silicon other than an amorphous type, and a Schottky junction type solar cell.

(Substrate) The substrate 201 is a member that mechanically supports the semiconductor layer in the case of a thin film solar cell such as amorphous silicon, and is also used as an electrode. Therefore, the substrate 201 is required to have heat resistance to withstand the heating temperature when forming the semiconductor layer 203, but may be conductive or electrically insulating.

Examples of conductive materials include Fe and N
i, Cr, Al, Mo, Au, Nb, Ta, V, Ti,
Metals such as Pt and Pb or alloys thereof, such as brass
, Stainless steel and other thin plates and their composites and carbon sheets
Sheet, galvanized steel sheet. In addition, electrically insulating material
As the material, polyester, polyethylene, polycarbonate
Nate, cellulose acetate, polypropylene, poly
Vinyl chloride, polyvinylidene chloride, polystyrene, poly
Heat resistant synthetic resin such as amide, polyimide, epoxy, etc.
Film or sheet or these and glass fiber,
With carbon fiber, boron fiber, metal fiber, etc.
Table of composites, thin plates of these metals, resin sheets, etc.
Metallic thin film and / or SiO of different materials on the surface₂, Si₃N
_Four, Al₂O ₃, Insulating thin film such as AlN is sputtered
The surface coating treatment was performed by the coating method, the plating method, etc.
And glass, ceramics, and the like.

(Lower Electrode) The lower electrode 202 is one electrode for taking out the electric power generated in the semiconductor layer, and is required to have a work function that makes an ohmic contact with the semiconductor layer. Examples of the material include Al, Ag, Pt, Au, Ni, Ti, Mo, Fe,
V, Cr, Cu, stainless steel, brass, nichrome, S
So-called simple metals or alloys such as nO ₂ , In ₂ O ₃ , ZnO and ITO, and transparent conductive oxides (TCO) are used. It is preferable that the surface of the lower electrode 202 is smooth, but in the case of causing irregular reflection of light, the surface may be subjected to a texture treatment. Further, when the substrate 201 is conductive, the lower electrode 202 need not be provided.

As a method of manufacturing the lower electrode, for example, plating, vapor deposition, sputtering or the like is used.

(Semiconductor Layer) As the semiconductor layer 203, a known semiconductor material generally used for thin film solar cells can be used. Examples of the semiconductor layer of the solar cell element used in the present invention include a pin junction amorphous silicon layer, a pn junction polycrystalline silicon layer, and CuInSe ₂ / C.
A compound semiconductor layer such as dS may be used. As a method for manufacturing the semiconductor layer, when the semiconductor layer is an amorphous silicon layer, it can be manufactured by introducing a raw material gas such as silane gas that forms a thin film into plasma CVD or the like for generating plasma discharge. . When the semiconductor layer is a pn junction polycrystalline silicon layer, for example, there is a method of forming a thin film from molten silicon. In addition, the semiconductor layer is CuIn
In the case of Se ₂ / CdS, it is formed by a method such as an electron beam vapor deposition method, a sputtering method, and an electrodeposition method.

(Upper Electrode) The upper electrode 204 is an electrode for taking out the electromotive force generated in the semiconductor layer and is paired with the lower electrode 202. Upper electrode 204
Is necessary in the case of a semiconductor having a high sheet resistance such as amorphous silicon, and is not particularly necessary in a crystalline solar cell since the sheet resistance is low. Also, the upper electrode 2
Since 04 is located on the light incident side, it needs to be transparent and is sometimes called a transparent electrode. Upper electrode 204
Has a light transmittance of 85% or more in order to efficiently absorb light from the sun or a white fluorescent lamp into the semiconductor layer. Furthermore, electrically, a current generated by light is applied to the semiconductor layer. On the other hand, it is desirable that the sheet resistance value is 100Ω / □ or less so that the sheet flows in the lateral direction. Examples of materials having such characteristics include SnO ₂ and In ₂
O ₃ , ZnO, CdO, CdSnO ₄ , ITO (In ₂ O ₃
+ SnO ₂ ) and other metal oxides.

[0039]

Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) In this embodiment, a stainless steel substrate is used as a base and amorphous silicon is used as a photovoltaic element, and the electrode structure thereof is shown in FIG.

FIG. 1 (a) is a schematic view of the surface on which the collector electrode is formed, as viewed from above. FIG. 1B is a sectional view of a portion AA ′ in FIG.

The photovoltaic element 101 in the figure is a structure having the multilayer film shown in Table 1.

Next, an ITO etching material (for example, Fe
The Cl ₃ ) -containing paste was screen-printed on the surface of the photovoltaic element 101 in the pattern 103. Then, by washing with pure water, a part of the ITO layer was removed to form an etching line 103, and electrical separation between the front surface electrode and the back surface electrode was ensured.

In order to ensure the insulation between the surface electrode and the lower electrode, which will be described later, a polyimide insulating tape 104 having a thickness of 130 μm was attached to the portion where the power generation region 102 and the substrate exposed surface are adjacent to each other.

Further, on the surface of the polyimide insulating tape 104, a thickness of 100 is formed as a conductor for taking out the surface electrode.
A copper foil 106 of μm was fixed by a heat-resistant double-sided tape 105. Here, a hard copper foil made by Fukuda Metal was used as the copper foil, and a 50 μm thick VHB9460 tape manufactured by Sumitomo 3M was used as the heat-resistant double-sided tape.

On the other hand, the wire 107 shown in FIG. 1 is a copper wire having a diameter of 100 μm, which is previously coated with a conductive adhesive and then dried. The conductive adhesive used was a pigment in which carbon black having a particle size of 3 to 5 μm was dispersed in an acrylic resin.

Next, the process of applying the conductive adhesive to the copper wire will be described with reference to FIG. The copper wire 301 includes a container 303 containing the conductive adhesive from a reel 302 that sends out the copper wire, a die 304, I.
Reel 306 for winding copper wire through R furnace 305
Was wound up in. At this time, the conductive adhesive is applied to the container 30.
200cc in 3 and wire speed is 1m
The speed of the reel is adjusted so that the reel is wound at a speed of / min. The copper wire 301 passes through the container 303, is coated with the conductive adhesive with a film thickness of 40 to 50 μm by a die 304, and is then dried in an IR furnace having a total length of 1 m and an internal temperature of 120 ° C. After that, it was taken by the upper reel.

With the above electrode structure, the electric power generated in the power generation region 102 of the amorphous silicon of the present embodiment is collected by the copper wire coated with the conductive adhesive which is the surface electrode, and the copper It is taken out by the hard copper foil fixed to the wire. Further, the back surface electrode is taken out from the stainless steel substrate through the back surface reflection layer ZnO film.

Next, a method of bonding the linear metal body and the conductor will be described. As the linear metal body, one having a conductive adhesive applied in advance by the above-mentioned method over the entire surface is used. FIG. 4 shows an apparatus used when producing the electrode structure shown in FIG. This device fixes a linear metal body to a conductor by a hot pressing method. The press surface 401 can be moved up and down by an air cylinder, has a heat source inside, and has a heat-conducting buffering agent 402 on its surface. The table 403 on which the substrate is placed has a heater built therein so that the substrate can be heated. The heat-conducting buffer used here was a laminate of fluororubber and aramid non-woven fabric, and a Yamauchi type-TB cushion material was used. The insulating tape, the heat-resistant double-sided tape, and the substrate that has undergone the process of forming a conductor are formed on the photovoltaic element substrate by using the pressing device 20.
It is loaded onto the table 403 heated to 0 ° C. Figure 3 after loading
In this apparatus, a copper wire having a hot-melt conductive adhesive applied to the entire surface in advance is laid. After that, 200 ℃
On the press surface that is heated to the buffer material 402 is stretched,
The copper wire and the hard copper foil were fixed by heating and pressurizing at a pressure of ² kg / cm ² . The time required for this step is 2 seconds for loading, 5 seconds for heating the substrate, 3 seconds for wiring, and 3 seconds for pressurizing and heating. afterwards,
It took out in 2 seconds. That is, this process is completed in about 15 seconds. Conventionally, it takes about 1 hour in total for the paste-like spot applying process and the drying process. Therefore, the manufacturing method of this example has higher mass productivity than the conventional method. Also, when fixing the copper wire to the effective surface of the photovoltaic element,
A method was used in which a hot-melt conductive adhesive was applied to a copper wire in advance and then fixed by heating and pressing.

By the way, Table 2 shows a photovoltaic element A having a collector electrode to which a conductor is attached after printing a conventional paste, and a photovoltaic element B having a collector electrode having the structure shown in this example. On the other hand, it is a result of evaluating various characteristics required for a solar cell. In addition, this result is the case when each electrode was formed in the photovoltaic element of 30 cm x 30 cm.

In the photovoltaic element B of this example, since the copper wire and the copper foil are fixed only by thermocompression bonding, the conductivity and reliability are concerned. However, while the series resistance Rs of the conventional photovoltaic element A is 30.3 Ωcm ² , the Rs of the photovoltaic element B of this example is 24.6 Ωcm.
^{Was 2} . Since the series resistance Rs is preferably as low as possible, it is judged that the photovoltaic element having the collector electrode having the configuration shown in this example has no problem in conductivity. In addition, the photovoltaic element B of this example had a satisfactory conversion efficiency of 7.82%. Further, the temperature-humidity cycle test was performed in the same manner as the soldering or the spot-like coating of the paste as shown in FIG. 6, and as a result, the deterioration rate of the photovoltaic element B of this example was less than 5%. From
It was confirmed that long-term reliability was also sufficient.

From the above results, it was found that the electrode structure according to the present invention can obtain high initial characteristics and long-term reliability in a simple process.

Example 2 This example is different from Example 1 in the following four points. (1) The member 104 of FIG. 1 is a silver foil having a thickness of 100 μm. (2) The member 105 of FIG. 1 is preliminarily coated with a thermosetting conductive adhesive on an aluminum wire having a diameter of 100 μm in an amount of 30 to 50 μm.
Points that have been applied. (3) A point that a block isocyanate and a carbon filler are dispersed in butyral resin is used as the thermosetting conductive adhesive. (4) The time distribution in the step of fixing the collector electrode to the conductor by a hot press machine was changed, and a post cure step was added after that.

Other points were the same as in Example 1.

The process of fixing the current collecting electrode used in this example to the conductor with a hot press machine and the required time are as follows: 2 seconds for loading the substrate, 3 seconds for wiring, and 5 seconds for heating the substrate. It takes 10 seconds to heat. Then, it was taken out in 2 seconds. The post-curing process after that is IR
Heating with a heater for 5 seconds.

By this method, the aluminum wire and the silver foil are fixed.

In the photovoltaic device C having the collector electrode of this example, the series resistance Rs was 27.6 Ωcm ² and the conversion efficiency was 7.85% (Table 2). That is, it was confirmed that, even if the members 104 and 105 in FIG. 1 were changed, when the post cure process was provided, the electrode structure could be produced by a simple process and high initial characteristics could be electrically obtained. . Furthermore, soldering as shown in FIG.
Alternatively, the temperature-humidity cycle test was carried out in the same manner as in the case where the paste was applied in spots, and it was confirmed that the photovoltaic element C of this example also had a deterioration rate of less than 5%. did it.

(Third Embodiment) This embodiment is different from the first embodiment in the following four points. (1) The member 104 of FIG. 1 is an aluminum foil having a thickness of about 1 μm and having a thickness of about 1 μm, which is plated with tin. (2) The member 105 shown in FIG. 1 is obtained by applying a thermosetting conductive adhesive to a silver wire having a diameter of 100 μm in advance by 40 to 50 μm. (3) As the thermosetting conductive adhesive, a urethane resin in which blocked isocyanate, graphite and ZnO are dispersed is used. (4) In the step of applying the thermosetting conductive adhesive to the silver wire, the step of changing the speed of the wire and the set temperature of the IR furnace and fixing the collector electrode to the conductor by a hot press machine Changes in time allocation.

Other points were the same as in Example 1.

The speed of the wire used in this example is 0.5 m /
min, and the set temperature of the IR furnace is 145 ° C. In addition, the content and time required for fixing the current collecting electrode used in this example to the conductor with a hot press machine are as follows: 2 seconds for loading the substrate, 3 seconds for wiring, 5 seconds for heating the substrate, and 5 seconds for heating under pressure. 20 seconds. Then, it was taken out in 2 seconds.

By this method, the silver wire and the tin-plated aluminum foil are fixed.

In the photovoltaic device D having the collector electrode of this example, the series resistance Rs was 27.9 Ωcm ² and the conversion efficiency was 7.72% (Table 2). That is, even if the members 104 and 105 shown in FIG. 1 are changed, in the step of applying the thermosetting conductive adhesive to the silver wire, if an appropriate wire speed and IR set temperature are selected, It was confirmed that the electrode structure could be made of another material and that high initial characteristics could be obtained electrically. Further, as a result of a temperature / humidity cycle test performed in the same manner as in the case where soldering or spot application of paste as shown in FIG. 6 was performed, it was found that the photovoltaic device D of this example also had a deterioration rate of less than 5%. From this, it was confirmed that long-term reliability is also sufficient.

[0063]

【The invention's effect】

(Claim 1) As described above, according to the invention of claim 1, when the linear metal body is arranged on the electrode forming surface and cured, the conductor for external output is also the conductive adhesive. Since it is possible to fix them at the same time using, it is possible to widen the selection range of the members 104 and 105 of FIG. 1, the thermosetting conductive adhesive, and the like. as a result,
It is possible to reduce costs while maintaining electrical characteristics and long-term reliability.

(Claim 6) According to the invention of claim 6, when the conventional collecting electrode and the external lead-out electrode are connected, the work of applying and curing the conductive adhesive is omitted. Therefore, the work process can be simplified. Further, when the linear metal body is arranged on the electrode formation surface and cured, the conductor for external output can also be fixed at the same time by using the conductive adhesive, which facilitates mass production line production. It can be constructed. As a result, it is possible to realize a low-cost and flexible production.

[Brief description of drawings]

1 is a schematic view of an electrode structure according to Example 1. FIG.

FIG. 2 is a schematic view of the photovoltaic element according to Example 1.

FIG. 3 is a schematic view of an apparatus for applying a conductive adhesive in advance over the entire length of a linear metal body according to the first embodiment.

FIG. 4 is a schematic view of an apparatus for fixing a linear metal body to a conductor using a conductive adhesive according to the first embodiment.

FIG. 5 is a schematic view of a photovoltaic device module according to a conventional example.

FIG. 6 is a diagram showing a deterioration rate of a photovoltaic element module according to a conventional example.

[Explanation of symbols]

 101 photovoltaic element, 104, 509 insulating tape, 106, 507 bus bar conductor electrode, 107, 506 current collecting electrode, 201, 501 substrate, 202, 502 back electrode layer, 203, 503 semiconductor layer, 204, 504 surface electrode layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuo Fujisaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. A photovoltaic element for generating an electromotive force by sunlight, and a linear element arranged on an effective surface of the photovoltaic element to collect electric power generated by the photovoltaic element. In the electrode structure of the photovoltaic element, which has at least a metal body and a conductor for collecting electric power from the linear metal body and leading it to the outside of the photovoltaic element, the linear metal body and An electrode structure of a photovoltaic element, wherein the conductor is fixed to the linear metal body by using a conductive adhesive applied over the entire length in advance. 2. The electrode structure of a photovoltaic element according to claim 1, wherein the linear metal body is made of at least one material of copper, silver, gold, nickel, and aluminum. 3. The electrode structure of a photovoltaic element according to claim 1, wherein the conductive adhesive is made of hot melt resin. 4. The electrode structure for a photovoltaic element according to claim 1, wherein the conductive adhesive is made of a thermosetting resin. 5. The conductor is copper, silver, gold, aluminum, lead,
The electrode structure of the photovoltaic element according to claim 1, wherein the electrode structure is made of at least one material of tin. 6. A photovoltaic element for generating an electromotive force by sunlight, and a linear element arranged on an effective surface of the photovoltaic element to collect electric power generated by the photovoltaic element. In the method for manufacturing an electrode structure of a photovoltaic element, which comprises at least a metal body and a conductor for collecting electric power from the linear metal body and leading the electric power to the outside of the photovoltaic element, Photovoltaic process comprising at least a step of applying the conductive adhesive to the metal body in advance over the entire length thereof, and a step of fixing the linear metal body to the conductor using the conductive adhesive. Method for manufacturing electrode structure of device.