JP3492182B2 - Oxide electrodeposition equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrodeposition apparatus for continuously depositing an oxide on a long substrate by using an electrochemical reaction.

[0002]

2. Description of the Related Art The present applicant has previously proposed a method of depositing an oxide on a long substrate by utilizing the electrochemical reaction of an aqueous solution as a method of depositing the oxide on the substrate. Here, the long substrate has various names such as a roll substrate, a web, a hoop material, a coil, a tape, and a reel material, but in the present invention, it is called a long substrate and is a thin plate having an extremely elongated rectangle, and a long direction. It can be rolled up and held in the form of a roll. Since the long substrate can be continuously formed into a film, the operating rate can be improved and the running cost can be reduced, and it is an industrially extremely advantageous member.

FIG. 2 is a schematic view showing an example of an electrodeposition apparatus using the above long substrate. Below, using the device, SU
A process of depositing a zinc oxide film on a long substrate including S will be described.

The long substrate 2001 is carried in the apparatus in the form of a coil wound on a bobbin. In this device, the coil is set on the substrate feeding roller 2002, and the interleaving paper wound for the surface protection is unwound by the interleaving paper winding roller 2003 while the substrate winding roller 2
It is conveyed toward 062. That is, the substrate 2001 enters the electrodeposition tank 2009 via the tension detection roller 2005 and the power feeding roller 2006. In the electrodeposition tank 2009, the support rollers 2013 and 2014 are positioned to perform electrodeposition. Next, it is sent to the washing tank 2030 and washed with water.
Positioning in the washing tank 2030 is performed by the support roller 203.
1 and 2066. Further warm air drying oven 2
It is dried in 051, the lateral deviation is corrected by the meandering correction roller 2059 after passing through the supporting roller 2057, and a new interleaving paper from the interleaving paper feeding roller 2060 is wound to protect the film formation surface, and is wound up by the substrate winding roller 2062. Is sent to the next step.

The tension detecting roller 2005 is used for the long substrate 20.
By detecting the dynamic winding tension of 01, feedback is applied to a braking means such as a powder clutch (not shown) linked to the shaft of the substrate feeding roller 2002 to keep the tension constant. As a result, the long substrate 2001
Is designed so that the conveyance path of the roller has a predetermined value between the support rollers. In particular, in the apparatus of FIG. 2, since the roller does not touch the film-forming surface, if the tension is weak, the long substrate 2001 may come off the supporting roller, or the electrodeposition tank 20 may be removed.
09, and the long substrate 2001 hangs down at the entrance / exit of the washing tank 2030, rubbing the film-forming surface and causing scratches. The device configuration in which the film-forming surface does not touch has the advantage that the film-forming surface is not damaged or soiled.In particular, micron-sized irregularities are formed on the thin film like the reflective layer of a solar cell. Preferred for applications where it must be.

The feeding roller 2006 is a long substrate 2001.
For applying a potential on the cathode side to the cathode, and is installed as close to the electrodeposition bath 2016 as possible, and is equipped with a power source 2008.
Is connected to the negative electrode side.

The electrodeposition tank 2009 holds the electrodeposition bath 2016, determines the path of the long substrate 2001, and installs the anode 2017 on the path of the long substrate 2001.
7, a positive potential is applied from the power source 2008 via the power feeding bar 2015. As a result, an electrochemical electrolytic deposition process in which the long substrate 2001 is negative and the anode 2017 is positive in the electrodeposition bath 2016 proceeds. Electrodeposition bath 201
When 6 is kept at a high temperature, the amount of steam generated is considerably large, so steam is allowed to escape from the steam discharge ducts 2010-2012. Further, in order to stir the electrodeposition bath 2016, air is introduced from a stirring air introduction pipe 2019,
Air is bubbled from an air blowing pipe 2018 in the electrodeposition tank 2009.

In order to replenish the electrodeposition bath 2009 with a high temperature electrodeposition bath solution, an electrodeposition circulation tank 2025 is provided, and a heater 2024 is installed therein to heat the electrodeposition bath, and the bath solution is bathed. It is supplied from the liquid circulation pump 2023 to the electrodeposition bath 2009 through the electrodeposition bath liquid supply pipe 2020. The electrodeposition bath solution overflowing from the electrodeposition tank 2009 or the bath solution for returning a part positively is returned to the electrodeposition circulation tank 2025 via a return path (not shown) and heated again. When the discharge amount of the pump is constant, as shown in FIG. 2, valves 2021 and 2022 are used to form the electrodeposition circulation tank 202.
It is possible to control the supply amount of the bath liquid from 5 to the electrodeposition tank 2009. That is, when increasing the supply amount, the valve 202
1 is more open and valve 2022 is more closed.
When reducing the supply amount, the reverse operation is performed. Electrodeposition bath 2
The holding water level of 016 is adjusted by adjusting this supply amount and the return amount (not shown).

A circulation pump 20 is provided in the electrodeposition circulation tank 2025.
A filter circulation system including a filter 27 and a filter is provided so that particles in the electrodeposition circulation tank 2025 can be removed. When the supply / return between the electrodeposition circulation tank 2025 and the electrodeposition tank 2009 is sufficiently large, a sufficient particle removing effect can be obtained by installing a filter only in the electrodeposition circulation tank 2025 as described above. be able to.

In the apparatus shown in FIG. 2, the electrodeposition circulation tank 2
025 also has a steam discharge duct 2026 installed,
The structure is such that water vapor is discharged. In particular, since a heater 2024 is installed in the electrodeposition circulation tank 2025 as a heating source, steam is remarkably generated, and when it is not desirable that the generated steam is inadvertently released or condensed, It is extremely effective.

The electrodeposition preparatory tank 2029 is installed in order to prevent the heated bath liquid from flowing into the existing waste liquid system at a stroke to damage the processing equipment. In addition to holding the electrodeposition tank 2009, the electrodeposition tank 2009 is emptied to improve work efficiency.

Long substrate 2 which has been electro-deposited in the electrodeposition tank 2009
Next, 001 enters the washing tank 2030 and is washed with water.
In the washing tank 2030, the long substrate 2001 is positioned by the supporting rollers 2031 and 2066, and the first washing tank 203
2. The second washing tank 2033 and the third washing tank 2034 are sequentially passed. The washing circulation tanks 2047 to 2049 and the water circulation pumps 2044 to 2046 are arranged respectively, and two valves, that is, valves 2038 and 2041, or 2039 and 2042, 2040 and 2043 determine the amount of water to be supplied to the washing tank 2030. Wash water is supplied to the washing tanks 2032 to 2034 through the pipes 2035 to 2037. The method of controlling the water supply amount by the two valves is the same as the method of controlling the bath liquid supply amount in the electrodeposition tank 2009. Further, similarly to the electrodeposition tank 2009, it is possible to return the return water (not shown), which collects overflow or positively returns a part thereof, to the respective washing circulation tanks 2050.

Generally, in the three-stage water washing system as shown in FIG. 2, the water washing tank on the upstream side of the substrate transfer, that is, the first water washing tank 2
From 032, the downstream washing tank, that is, the third washing tank 2034
Purity of washing water becomes higher toward. This means that the cleanliness of the long substrate 2001 increases as the long substrate 2001 is transported and the process comes to the end. This means that as shown in FIG. 2, the washing water is first supplied to the third washing circulation tank 2049, and then the washing water overflowing in the third washing circulation tank 2049 is supplied to the second washing circulation tank 2
048, and by further supplying the wash water overflowing in the second water washing circulation tank 2048 to the first water washing circulation tank 2047,
This can be achieved by significantly reducing the amount of water used.

The long substrate 2001 which has been washed with water is drained by an air knife 2065 provided in a part of the washing tank 2030, and then is conveyed to a warm air drying furnace 2051. Here, the drying is performed with convection air having a temperature sufficient to dry the water. Convective air for that purpose removes dust from the hot air generated in the hot air generating furnace 2055 through the filter 2054, and blows it out from the hot air introducing pipe 2052 to supply the hot air. The overflowing air is again collected from the warm air collecting pipe 2053, mixed with the outside air from the outside air introducing pipe 2056, and sent to the hot air generating furnace 2055. The conveyance path of the long substrate 2001 in the warm air drying oven 2051 is positioned by the support roller 2066 and the support roller 2057.

The meandering correction roller 2059 is used for the long substrate 2.
This is an object to be wound around the substrate winding roller 2062 by correcting the widthwise deviation of 001, and the amount of deviation is detected by a sensor (not shown), and the meandering correction roller 2059 is controlled by rotating it using an arm (not shown) as a fulcrum.
The deviation detected by the normal sensor is also corrected by the meandering correction roller 2.
The operation amount of 059 is also extremely small and does not exceed 1 mm. Even when the long substrate 2001 is wound up, new interleaving paper is supplied from the interleaving paper feeding roller 2060 for surface protection.

Stopper 2007 and stopper 2058
Simultaneously work to make the long substrate 2001 stand still while the transport tension is applied. Thereby, the long substrate 2
Workability can be improved during replacement of 001 and maintenance of the apparatus.

The use of the apparatus shown in FIG. 2 generally has the following advantages.

(1) Unlike vacuum equipment such as sputtering,
Film deposition is extremely simple. No expensive vacuum pump is needed, and there is no need to consider the power supply for using plasma or the design around the electrodes.

(2) In most cases, the running cost is lower than that of sputtering. This is because sputtering requires labor and equipment to manufacture a target, is costly, and has a low target utilization efficiency of 20%. Therefore, when the throughput of the apparatus must be increased or when the film thickness is large, the target replacement work occupies a considerable weight.

(3) It is superior in terms of equipment and running cost compared to CVD methods other than sputtering and vacuum evaporation methods.

(4) The obtained film is in many cases composed of polycrystalline fine particles, and shows conductive properties and optical properties comparable to those produced by the vacuum method, and a sol-gel method or a coating method using an organic substance, Furthermore, it is superior to the spray pyrolysis method.

(5) In addition to the above advantages in the case of forming an oxide, the waste liquid can be easily treated, the influence on the environment is small, and the cost for preventing environmental pollution is low.

[0023]

As described above, as shown in FIG.
The zinc oxide film can be deposited on a long substrate at a very low cost by using the electrodeposition apparatus shown in FIG. When a flat zinc oxide film without irregularities is required, the zinc nitrate concentration may be 0.001 mol / l, and the resistance of the electrodeposition bath in this case is that the electrode area of the zinc anode is 100 mm × 2.
Since it is 14Ω when the distance from the substrate is 1 cm at 00 mm, some stray current due to the lead wire, the substrate, and other SUS baths does not substantially affect. However, if an unevenness of about 1 μm is positively formed on the surface of the zinc oxide film to be formed, for example, the zinc nitrate concentration is 0.2 mo.
1 / l is required, and therefore, the electric conductivity of the electrodeposition bath at a temperature of 80 ° C. becomes 70 mS / cm, which is extremely low in resistance. With this conductivity, the electrode having the above size has a resistance value of 0.07Ω. This is comparable to the resistance value of a lead wire having a length of several meters and a long substrate having a length of several meters. Regardless of the concentration of zinc nitrate in the electrodeposition bath, the film formation rate is mostly determined by the current flowing through the substrate.Therefore, when a zinc oxide film with unevenness is formed by the electrodeposition method, the effect of the stray current is large. In particular, a long substrate has a great influence. Even if the stray current is large, it is possible to control it if it is a constant value. However, according to the study by the present inventors, the stray current is extremely unstable in the long film forming apparatus. The surface on which the zinc oxide film was formed to form the film had a large variation and unevenness both in terms of characteristics and visually.

For the roller used in the apparatus shown in FIG. 2, a metal such as a simple substance of Al, Cu, Fe or the like or an alloy of SUS, brass or the like is used. Further, if the strength and accuracy are sufficient, it may be made of wood or plastic, but generally, in order to hold and convey a long substrate, 0.1 kg or more per 1 cm width, preferably, 2.
It is necessary to apply a tension of 5 kg or more, and a metal precision is preferable because it requires a machine precision of 0.5 mm or less in order to make the conveyance good without deviation. Above all, SUS is mentioned as a preferable material from the viewpoint of strength and corrosion resistance.

The roller has a shaft and is fixed by a bearing. As the bearing, a bearing bearing, a sliding bearing or the like can be used. When the long substrate is conveyed over a long path of 10 m or more, the number of rollers increases, so that a bearing bearing is preferable from the viewpoint of mechanical accuracy and reduction of rolling resistance. Generally, in terms of price, the bearing and the bearing are made of metal. Therefore, when the metal roller is used, the long substrate is electrically connected to the device via the bearing.

Each of the rollers has a function, and according to the function, the substrate is held and sequentially fed out to the electrodeposition apparatus, the "feeding roller", the "rolling roller" that winds up the treated substrate, and the substrate. It is called a "conveying roller" related to the conveyance of the substrate, a "power feeding roller" for supplying or collecting a current to the substrate, a "meandering correction roller" for adjusting and correcting the meandering of the substrate. It is easy to use any of these rollers as a metal (or SUS) roller as described above in terms of function expression. However, if at least one of them is grounded via a bearing, the entire substrate will be grounded. I will have. Moreover, the electric resistance of this grounding path is extremely unstable because it passes through the bearing.

On the other hand, since the apparatus main body is set to the ground potential, when a metal-made electrodeposition tank is used and the bath pipe leading to the electrodeposition tank through the frame is formed of metal. The electrodeposition tank is connected to the ground potential through the pipe, and further, when the pump is connected, the electrodeposition tank is connected to the ground potential through the pump.
Further, even when they are connected by an insulating pipe, they are at the ground potential when the electric resistance of the electrodeposition bath is low. Since such ground potential passes through the electrodeposition bath, piping, tank, and frame, the resistance is relatively unstable. Further, when the roller serves as a grounding path, the long substrate is grounded with an unstable resistance. Originally, electrodeposition is the stable deposition of zinc oxide by passing a current that causes a stable electrochemical reaction between the anode electrode and a long substrate having a cathode potential. Due to the existence of the current, a part of the current flows into the electrodeposition tank and a part flows to the ground potential, so that the current between the anode and the cathode (here, the long substrate) becomes extremely unstable.
This is the substance of the above-mentioned stray current.

Such a stray current is, as described above,
Affects the zinc oxide film, causing variations and unevenness in characteristics and visual observation. In particular, when the concentration of zinc nitrate is increased to form irregularities on the surface, the influence thereof becomes remarkably large, which becomes a great barrier to actual industrialization.

An object of the present invention is to solve the above problems, prevent the influence of a stray current in the step of depositing an oxide on a long substrate by electrodeposition, and form an oxide film without variations or unevenness. To provide a device.

[0030]

The present invention relates to an oxide electrodeposition apparatus for continuously depositing an oxide film on a long substrate by electrodeposition while transporting the long substrate. Substrate feeding roller, support roller, tension test that contacts the substrate
Roll-out roller, meandering correction roller, substrate winding roller
Is a float potential, and the power feeding roller is an independent potential, which is an oxide electrodeposition apparatus.

In the present invention, the influence of the stray current on the long substrate is prevented by setting the potential of the roller, which can come into contact with the long substrate and serves as a path for the stray current, to a float potential or an independent potential. Specifically, in the case of a metal roller, for example, by coating the surface with an insulator, or by electrically isolating the roller bearing from other members via an insulating plate. It can be a float potential.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION The basic structure of an oxide electrodeposition apparatus of the present invention and a film forming method by electrodeposition of an oxide layer using the apparatus are exemplified by the apparatus shown in FIG. This is the same as the conventional electrodeposition apparatus using a long substrate and the film forming method using the apparatus. In the present invention, at least a roller in contact with a long substrate, for example, a substrate feeding roller 2002, a tension detecting roller 2005, a power feeding roller 2006, a meandering correction roller 2059, a substrate winding roller 2062, a supporting roller 2031 and a supporting roller 2031 and 2 in the apparatus of FIG.
Regarding 057 and 2066, by setting a float potential or an independent potential depending on the function of each roller, it is possible to prevent the occurrence of the stray current described above, and to lengthen an oxide film that is uniform in characteristics and visually. It can be deposited on a standard substrate. Hereinafter, each member according to the present invention will be described.

(Substrate) The long substrate used in the present invention can be used as long as it has electrical continuity on the film formation surface and is not attacked by the electrodeposition bath. Specifically, metals such as SUS, Al, Cu, Fe and Cr are used. Among these, SUS is relatively inexpensive and excellent in anticorrosion in order to perform the element formation process in a later step.
It is suitable for the present invention.

The surface of the substrate may be smooth or rough. Furthermore, another conductive material may be formed on these substrates, and it is selected according to the purpose of electrodeposition.

When a long SUS substrate is used, the specific electric resistance is larger than that of other metals. Therefore, when the thickness of the substrate is about 0.1 mm or less, the resistance of the substrate is less than that of the above electrodeposition bath. Often greater than the resistance of the anode through the substrate. In such a case, it is difficult to control the anode potential with respect to the substrate, or it is difficult to control the current that should flow between the substrate and the anode by escaping from other members such as the tank itself or the piping. The difficulty of control often results in the problem of unevenness as described in the subject of the present invention, and the present invention is particularly effective in such a case.

(Electrodeposition Bath) The electrodeposition bath used in the present invention is selected according to the oxide to be deposited. For example, in the case of zinc oxide film formation to which the present invention is preferably applied, zinc nitrate ( Those mainly composed of hexahydrate are applicable. In addition, saccharides such as sucrose and dextrin can be added to improve the uniformity of the film.

The electric conductivity of the electrodeposition bath used in the present invention is preferably 1 mS / cm or more in the case of zinc oxide film formation, and particularly preferably 10 mS / cm or more to obtain a preferable oxide film. When a high-conductivity electrodeposition bath is used, a current other than the current path flowing from the anode to the substrate, that is, a stray current can be stabilized or reduced to stabilize or improve the current flowing from the anode to the substrate. Such an electrodeposited film is easily formed.

In order to form a zinc oxide film having irregularities of about the wavelength of light effective as a light confining reflection layer of a solar cell, the concentration of zinc nitrate is preferably 0.1 mol / l or more. In order to obtain a zinc oxide film oriented in the c-axis, it is generally 0.05 mol / l or less, though it depends on the substrate. In any case, when sugar is added, sucrose is preferably 3 g / l or more and dextrin is preferably 0.1 g / l or more.

Further, the temperature of the electrodeposition bath is preferably 60 ° C. or higher in the case of zinc oxide film formation, since there is no metal precipitation.
Particularly, it is preferably 80 ° C. or higher because the uniformity of the obtained film is improved. At such a high temperature, the conductivity of the electrodeposition bath is remarkably increased, so that a more preferable film can be obtained.

(Roller) In the present invention, the roller that comes into contact with the long substrate has a float potential or an independent potential. As the roller according to the present invention, a metal roller suitable for a normal bearing bearing is used when the conveyance tension of a long substrate is large.
Above all, the SUS roller is excellent in corrosion resistance and mechanical strength, and can be suitably used. Further, the metal roller is easy to remove dirt and has good long-term use stability.

The roller used as the power feeding roller always receives a current on the surface which comes into contact with the long substrate, or in order to pass the current, the contact portion is made of metal, is connected to the electrodeposition power source, and has a predetermined independent potential. have. In order to enhance the effect of power feeding, it is necessary to make a large contact portion, and it is preferable to take a large amount of winding the substrate around the roller.

In the present invention, in order to set the metal roller to an independent potential or a float potential, the bearing may be electrically isolated from other members by attaching the bearing to the frame via an insulating plate. In addition, if there are relatively few restrictions due to strength or if you do not want to damage the contact surface of the long substrate, either configure the roller itself with an insulator such as resin, or cover the surface of the metal roller with an insulator. By using such a roller, the potential of the roller can be set to a float potential. In that case, it is not necessary to consider electrical insulation of the bearing frame, and the degree of freedom in installation design is increased. Further, such a roller can be arranged in the electrodeposition bath.

FIG. 1 shows an example of a structure in which the bearing is attached to a frame via an insulating plate. 1000 in FIG.
Is a roller, and when fixing the bearing 1002 on the main body frame 1001 of the device with the SUS M10 bolt 1003 and the SUS nut 1004, the insulating spacer 1006, the bolt head and the bearing 1002 are provided between the frame 1001 and the bearing 1002. An insulating washer 1005 is inserted between them, and an insulating washer 1007 is inserted between the nut 1004 and the frame 1001. Further, the bolt hole of the bearing is made larger than the bolt diameter, and the bolt 1003
A cylindrical insulating collar 1008 is arranged around the so as to prevent the bolt from coming into contact with the bearing due to the displacement of the bearing. In this configuration, the insulating spacer 100
6 is an insulator according to the present invention, and is an insulating washer 100.
5, 1007, and the insulating collar 1008, they are formed of an insulator described later.

In the present invention, the float potential means that an electrically closed circuit is not formed. For example, in FIG.
In the device shown in (1), the electric current is flown to a predetermined value through the anode 2017, but most of the electric current desirably returns from the power supply roller 2006 to the power source 2008. As mentioned above, since the electric resistance of the electrodeposition bath is extremely small,
Due to the voltage drop due to the resistance of the substrate, the supporting roller 2031
And 2066 have different potentials. This potential is applied to the long substrate 20.
A state in which the potential of 01 is not connected to another potential source is called a float potential.

(Insulator) In the present invention, the insulating plate (insulating spacer) interposed between the bearing and the frame for setting the metal roller to the float potential, and the insulator forming the insulating washer and the insulating collar are alumina. , Ceramics including magnesia, calcia, silicon nitride, silicon carbide; lead potassium, lead potassium soda, zinc borosilicate, aluminosilicate,
Glass such as borosilicate, barium borosilicate, alkali barium; polystyrene, polyparamethylstyrene,
AAS (acrylonitrile / acrylate / styrene copolymer), ABS (acrylonitrile / butadiene / styrene copolymer), ACS (acrytonitrile / chlorinated polyethylene / styrene copolymer), AES (acrylonitrile / ethylene / styrene copolymer) , AS (acrylonitrile-styrene copolymer) and other styrene-based resins; EVC (ethylene-vinyl chloride copolymer), EVA
(Ethylene / vinyl acetate copolymer), PVC (polyvinyl chloride), VP (vinyl propionate polymer), PVB
(Polyvinyl butyral), PVF (polyvinyl formal) and other vinyl resins; PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene / propylene copolymer), PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer) Polymer), ETFE (tetrafluoroethylene / ethylene copolymer), CTFE (polychlorotrifluoroethylene), PVDF (polyvinylidene fluoride), ECTFE (trifluorochloroethylene / ethylene copolymer), PVF (polyfluoride) Fluorine resin such as vinyl chloride); polyacetal resin; polyamide resin including nylon; polyamideimide resin; polyarylate resin; polyimide resin; LDPE (low density polyethylene), LLDPE (linear low density polyethylene), HD
Polyethylene resin such as PE (high density polyethylene) and UHMWPE (ultra high molecular weight polyethylene); polyester resin such as PET (polyethylene terephthalate), PBT (polybutylene terephthalate) and polycarbonate; propylene resin such as polypropylene; PMMA
Acrylic resin such as (polymethylmethacrylate); B
Epoxy resin such as PA (bisphenol A); DAP
Allyl resins such as (diallyl phthalate); Phenolic resins such as Bakelite; Unsaturated polyester resins; Furfuryl alcohol polymers, furfuryl alcohol / furfural copolymers, furfural / phenolic copolymers, furfural / ketone copolymers, etc. Furan resin;
Urethane resin; urea resin can be applied.

Further, a mixture of the above materials or a composite material with fibers known as FRP (fiber reinforced plastic) can be used. Furthermore, SBR (styrene
Butadiene rubber), BR (butadiene rubber), IR (isoprene rubber), NBR (acrytonitrile-butadiene rubber), CR (chloroprene rubber), IIR (butyl rubber), urethane rubber, silicone rubber, hydrogenated nitrile rubber, fluororubber , ACM (acrylic rubber), ethylene / acrylic rubber, and other synthetic rubbers can also be used.

Further, in the present invention, when the surface of the metal roller is used by being coated with an insulator, the insulator is
It is desirable that it has excellent electrical insulation properties, excellent workability, and strength that allows the substrate to be held and transported while facing the tension of the substrate. Specifically, among the above-mentioned insulators, styrene resin, vinyl resin, fluororesin, polyacetal resin, polyamide resin, polyamideimide resin, polyarylate resin, polyimide resin, polyethylene resin, polyester resin, styrene resin, propylene. Resin, acrylic resin, epoxy resin, allyl resin, phenol resin, unsaturated polyester resin, furan resin, urethane resin, urea resin can be applied. Further, it may be a mixture of these materials or FRP. Also, SB
It is possible to use synthetic rubbers such as R, BR, IR, NBR, CR, IIR, urethane rubber, silicone rubber, hydrogenated nitrile rubber, fluororubber, ACM, and ethylene / acrylic rubber.

The above-mentioned insulator can be covered with a sponge-like or thin-film-like coat in addition to covering the metal roller as a thick film coat.

In the present invention, the roller contacting the long substrate is set to an independent potential or a float potential, but other rollers, for example, the interleaf paper winding roller 2003 and the interleaf paper feeding roller 20 in the apparatus of FIG.
Also for 60, a metal is used for the interleaving paper and the interleaving paper bobbin, and when the interleaving paper bobbin is installed, a stray current is generated through the interleaving paper and the interleaving paper bobbin. As described above, it is desirable to set the float potential.

[0050]

EXAMPLES Example 1 The insulating structure of FIG. 1 is replaced with a supporting roller 201 of the apparatus of FIG.
Applied to all rollers except 3, 2014, 2031. That is, the substrate feeding roller 2002, the interleaf paper winding roller 2003, the tension detection roller 200
5, power feeding roller 2006, supporting roller 2036, supporting roller 2057, meandering correction roller 2059, substrate winding roller 2062, interleaving paper feeding roller 20
60.

The insulating spacer 1006 shown in FIG.
As the insulating washer 1005 and 1007, a Teflon washer having a thickness of 5 mm was used, and as the insulating collar 1008, a cylindrical collar having a thickness of 3 mm was used.

The insulating structure of the interleaf paper winding roller 2003 and the interleaf paper feeding roller 2060 is adopted because the interleaf paper used in this embodiment is P vapor-deposited on one side with Al.
This is because a stray current is generated when the rollers 2003 and 2060 are at the ground potential via the Al vapor deposition layer and via the SUS interleaving paper bobbin. Further, the interleaf paper winding roller 2003 is driven by a motor (not shown) and a chain connected to the motor, but the entire motor is also arranged in the insulating structure of FIG. In addition, the interleaf feeding roller 2060 is actually braked by a clutch (not shown) and a chain connected to it,
The entire clutch is also arranged with the same insulation structure. With such an insulating structure, the interleaf paper winding roller 20
03 and the slip sheet feeding roller 2060 can be set to a float potential, and a stray current can be prevented from occurring through the slip sheet.

The substrate feeding roller 2002 actually applies a clutch (not shown) and a chain connected to the clutch (not shown), but the entire clutch is also arranged in the insulating structure shown in FIG. Substrate winding roller 20
Although 61 is actually driven by a motor (not shown) and a chain connected to it, the entire motor is also arranged with the same insulating structure. As a result, the substrate feeding roller 2002 and the substrate winding roller 2061 can be set to the float potential, and it is possible to prevent the generation of a stray current through the long substrate 2001 in these roller portions.

Further, since the abutting portion of the stopper 2007 that abuts on the tension detecting roller 2005 is covered with a resin made of Teflon, by applying the insulating structure of FIG. It is possible to prevent the generation of a stray current through the long substrate 2001 in the tension detection roller 2005 when the stopper is operating and when it is opened. This is stopper 205
The same applies to the support roller 2057 having a structure with which 8 abuts.

Support rollers 2013, 2014, 203
Reference numeral 1 denotes a roller made of non-magnetic SUS304 having a built-in magnet, which is almost in contact with the long substrate 2001 and is less affected by tension, and the electrodeposition bath 2016
To be buried in the Furon Co. It is fastened to the electrodeposition tank 2009 with a bearing collar made by "Luron" manufactured by the company. Therefore, these supporting rollers have a float potential, and it is not necessary to consider generation of a stray current from these rollers.

The support roller 2066 and the meandering correction roller 2059 can be made to have a float potential by adopting the insulating structure of FIG. 1 for the bearings thereof, and the stray current of the stray current through the long substrate 2001 in these roller portions can be set. Occurrence can be prevented.

The insulating structure shown in FIG. 1 is also applied to the power feeding roller 2006, but this roller is electrically set to an independent potential connected to the power source 2008 instead of the float potential. When the electrodeposition tank 2009 is made of metal and is grounded, if the negative side of the power source 2008 is grounded, it is almost 0 V with respect to ground, and if the positive side of the power source 2008 is grounded, it is the power supply voltage portion with respect to ground. Has a negative potential. Power supply 20
Which of positive and negative 08 is grounded is determined by the condition of electrodeposition. That is, the positive side of the power supply 2008 should be grounded when it is desired to set the potential of the tank to the same potential as the anode 2017, and the negative side of the power supply 2009 is set to the same level as the cathode long substrate 2001. Ground side. In this embodiment, the positive side of the power source 2008 is grounded. As a result, the current flowing from the anode 2017 to the electrodeposition bath 2009 could be reduced without providing any special means. The potential of the power supply roller 2006 was maintained by using a carbon sliding brush.

Using the apparatus having the above-mentioned structure, from the electrodeposition bath 2016 of zinc nitrate of 0.2 mol / l containing 0.7 g / l of dextrin at 80 ° C., the conveying speed of the long substrate 2001 is 400 mm / sec, and the anode is Current density 8mA / cm
^{2 to} 2 μm thick zinc oxide film by sputtering
A film was formed on a long substrate (SUS430 (2D surface)) on which 000 Å Al and 1000 Å zinc oxide were sequentially formed as bases. The microstructure of this film confirmed by an electron microscope (SEM) had irregularities with a pitch of about 1 μm or less. From the trace by an atomic force microscope (AFM), it was found that the inclination of the unevenness was 20 ° with respect to the horizontal plane. Using the zinc oxide film formed by this electrodeposition as a light confinement layer, a CVD device for a long substrate is used to form a solar battery cell having a triple structure of amorphous silicon (a structure in which three pin elements are stacked). An upper electrode of ITO (Indium-Tin-Oxide) was formed, and macro characteristics were determined from the characteristics of the solar cell and its distribution.

When the CVD film is formed, the film thickness unevenness and abnormal growth marks are very clearly visible, but are much more uniform than when many stray currents exist (that is, before application of the present invention). Appeared in appearance.

Regarding the solar cell characteristics, the short-circuit current density J _{sc, which} is an evaluation criterion for the zinc oxide optical confinement layer manufactured in this example, is 7.4 to 7.6 mA / cm ² , and the triple-structure top layer is particularly preferable. It is confirmed from the measurement of Q that the current is regulated by the current of 1. Although there is a loss due to some imbalance in current balance, the variation seen from the whole substrate is extremely small and good characteristics were obtained. From this, it can be seen that the optical reflection characteristic has sufficient reflectance itself and its scattering property.

The series resistance R _s of this cell is 1c.
It was 32 to 34 Ω per m ² , and on the other hand, the frequency of short-circuiting the cells was 5% or less, and it was confirmed that the electrical characteristics were good.

[Embodiment 2] The negative side is grounded instead of the positive side ground of the power source 2008 in Example 1, and the other parts are the same as the apparatus used in Example 1. However, the current supplied from the power source 2008 is grounded on the negative side, and therefore the anode 2017 via the electrodeposition bath 2016.
From the above, an increase in the amount of current flowing to the electrodeposition tank 2009 was observed. However, unlike the so-called stray current, this current shows a constant value during the deposition of zinc oxide on the long substrate 2001, so that controllability was not sacrificed. For example, 60% of the current flowing from the anode 2017 flows to the electrodeposition tank 2009, and 40% flows to the long substrate 2001.
The percentage shows a constant value from beginning to end.

With the above structure, 0.7 g of dextrin is used.
/ L containing 0.2 mol / l, 80 ° zinc nitrate electrodeposition bath 2016 from the long substrate 2001 transport speed 350
A zinc oxide film having a thickness of 2 μm was formed on Example 1 and the long substrate at a current density of 20 mA / cm ^{2 and a} current density of 20 mA / cm ² . The microscopic structure of this film confirmed by an electron microscope (SEM) was similar to that of Example 1, in which irregularities having a pitch of about 1 μm or less were formed. From an atomic force microscope (AFM) trace, the slope of this unevenness is 19 with respect to the horizontal plane.
It turned out to be °. Using the zinc oxide film formed by this electrodeposition as a light confinement layer, a CVD device for a long substrate is used to form a solar battery cell having a triple structure of amorphous silicon, and further an upper electrode of ITO is formed. Macroscopic characteristics were determined from the battery characteristics and their distribution.

The solar cell visually showed the same appearance as the solar cell of Example 1.

Regarding the solar cell characteristics, the short-circuit current density J
_{The sc} is 7.3 to 7.7 mA / cm ² , and it is supported by the measurement of Q that it is regulated by the current in the top layer of the triple structure, and some loss of current balance results in loss. However, there were very few variations seen from the whole substrate, and good characteristics were obtained. From this, it was found that, as in Example 1, the optical reflection characteristics had sufficient reflectance and scattering properties.

The series resistance R _s of this cell is 1c.
It was 32 to 34 Ω per m ² , and on the other hand, the frequency of short-circuiting the cells was 5% or less, and it was confirmed that the electrical characteristics were good.

[Embodiment 3] FIG. 3 shows a perspective view of a roller used in this embodiment and having a contact surface with a substrate covered with an insulator. In the figure, 3001 is SU
S roller shaft, SUS base roller 3002
Is welded to the base roller 3002 and has a wall thickness of 7
An insulating coating 3003 made of mm vinyl resin is formed. Although this roller costs more, it eliminates the need to insulate the mechanical links from the bearings, such as chains, motors, and clutches, which improves design flexibility and simplifies device manufacturing. . Moreover,
It can be placed in an electrodeposition bath, and the substrate can be supported on the film-forming surface of a long substrate.

The resin coating roller was placed on the substrate film-forming surface between the supporting rollers 2014 and 2031 of the apparatus used in Example 1, and the transport path of the long substrate 2001 was greatly lifted. As a result, the overflow depth of the electrodeposition bath 2016 at the inlet and the outlet of the electrodeposition tank 2009 can be kept the same, and the uniformity of the electrodeposition bath circulation is improved. Further, in order to prevent the long substrate 2001 from drying before reaching the washing tank 2032, a pure water shower was applied from the roller side.

With the same electrodeposition bath and electrical constitution as in Example 1,
A zinc oxide film was formed on the same long substrate as in Example 1. The microscopic structure of this film confirmed by an electron microscope (SEM) was similar to that of Example 1, in which irregularities having a pitch of about 1 μm or less were formed. From the trace by an atomic force microscope (AFM), it was found that the inclination of this unevenness was 19 ° with respect to the horizontal plane. The structure of the microscopic film did not change despite the fact that there was roller contact on the film formation surface, and no scratches or breakage of irregularities was observed.

Using the zinc oxide film formed by this electrodeposition as a light confining layer, a solar cell having a triple structure of amorphous silicon was formed by a CVD device for a long substrate, and an upper electrode of ITO was further formed. Then, macroscopic characteristics were determined from the solar cell characteristics and their distribution.

The solar cell visually showed the same appearance as the solar cell of Example 1.

Regarding the solar cell characteristics, the short-circuit current density J
_{The sc} is 7.3 to 7.6 mA / cm ² , and it is supported by the measurement of Q that it is controlled by the current of the top layer of the triple structure, and it is lost due to some imbalance in the current. However, there were very few variations seen from the whole substrate, and good characteristics were obtained. From this, it was found that, as in Example 1, the optical reflection characteristics had sufficient reflectance and scattering properties.

The series resistance R _s of this cell is 1c.
It was confirmed that it was 32 to 36 Ω per m ² , while the short circuit of the cell was less than 5% in frequency, and the electrical characteristics were also good.

[0074]

As described above, according to the electrodeposition apparatus of the present invention, an oxide film, particularly a zinc oxide film having irregularities formed on the surface thereof, causes variations and unevenness in characteristics on a long substrate. It can be formed uniformly and can be applied to a solar cell having uniform characteristics.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a configuration in which a roller according to the present invention has a float potential.

FIG. 2 is a diagram showing an example of an electrodeposition apparatus of the present invention.

FIG. 3 is a perspective view of a roller used in Example 3 of the present invention.

[Explanation of symbols]

1000 roller 1001 body frame 1002 bearing 1003 bolt 1004 nut 1005, 1007 insulating washer 1006 insulating spacer 1008 insulating collar 2001 long substrate 2002 substrate feeding roller 2003 interleaf winding roller 2005 tension detection roller 2006 power feeding roller 2007, 2058 stopper 2008 power supply 2009 electric power Deposition tanks 2010, 2011, 2012, 2026 Discharge duct 2015 Power supply bar 2016 Electrodeposition bath 2017 Anode 2018 Air blowing pipe 2019 Stirring air introduction pipe 2020 Electrodeposition bath liquid supply pipe 2021, 2020, 2028, 2038-2043
Valve 2023 Bath liquid circulation pump 2024 Heater 2025 Electrodeposition circulation tank 2027 Circulation pump 2029 Electrodeposition preliminary tank 2030 Water washing tank 2013, 2014, 2031, 2057, 2066
Support roller 2032 First water washing tank 2033 Second water washing tank 2034 Third water washing tank 2035 to 2037 Water supply pipe 2044 to 2046 Water circulation pump 2047 First water washing circulation tank 2048 Second water washing circulation tank 2049 Third water washing circulation tank 2050 Water washing circulation tank 2051 Warm air drying oven 2052 Warm air introducing tube 2053 Warm air collecting tube 2054 Filter 2055 Hot air generating furnace 2056 Outside air introducing tube 2059 Meandering correction roller 2060 Interleaf sheet feeding roller 2062 Substrate winding roller 2065 Air knife 3001 Roller shaft 3002 Underground roller

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuichi Sonoda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Bibliography 6-12470 (JP, U) (58) Survey Fields (Int.Cl. ⁷ , DB name) C25D 9/04 H01L 31/04

Claims (5)

(57) [Claims] 1. An oxide electrodeposition apparatus for transporting a long substrate and continuously depositing an oxide film on the long substrate by electrodeposition , the substrate feeding roll being in contact with the long substrate.
Rail, support roller, tension detection roller, meandering correction roller
And the substrate winding roller are at float potential,
An oxide electrodeposition apparatus characterized in that the electric roller has an independent potential. 2. The oxide electrodeposition apparatus according to claim 1, wherein at least one roller is made of metal. 3. The oxide electrodeposition apparatus according to claim 2, wherein the bearing of the roller formed of the metal is electrically separated from other members by an insulating plate, and the roller has a float potential. 4. The oxide electrodeposition apparatus according to claim 1, wherein at least one roller is made of a metal whose contact surface with the long substrate is covered with an insulator. 5. The oxide electrodeposition apparatus according to claim 1, wherein the oxide film is a zinc oxide film.