Electrolysis: processes – compositions used therein – and methods – Electrolytic coating – Treating electrolytic or nonelectrolytic coating after it is...
Reexamination Certificate
1999-02-12
2002-10-29
Nguyen, Nam (Department: 1741)
Electrolysis: processes, compositions used therein, and methods
Electrolytic coating
Treating electrolytic or nonelectrolytic coating after it is...
C205S199000, C205S138000, C205S333000, C205S917000, C427S255180, C438S758000
Reexamination Certificate
active
06471848
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrodeposition apparatus and an oxide film forming method for forming an oxide film by electrodeposition (which includes electrolytic plating and electrolytic deposition, both having the same meaning) on a long substrate such as a stainless steel belt-like plate, and more particularly to an electrodeposition apparatus and an oxide film forming method for uniformly forming a zinc oxide film on the substrate.
2. Related Background Art
In the production of photovoltaic elements, the technology of forming oxide on a substrate by an electrochemical reaction in an aqueous solution is being investigated as an atternative the vacuum process. For example, the Japanese Patent Laid-Open Application No. 09-092861 proposes “a method of producing a photovoltaic element” and discloses “a method of forming an oxide such as zinc oxide on a long substrate by electrodeposition and an apparatus therefor”.
FIG. 2
is a schematic view showing an example of the apparatus for forming an oxide by electrodeposition, which was prepared by modifying the apparatus described in the above-mentioned patent application by the present inventors, and simplified to function only to form a zinc oxide film by electrodeposition. The apparatus shown in
FIG. 2
does not constitute the prior art.
In
FIG. 2
, a long substrate
2001
of stainless steel is fed from a rolled stainless steel sheet, which is also called a hoop material, a roll-type substrate or a web. The long substrate
2001
is transported to the apparatus in the state of a coiled substrate, wound on a bobbin.
In the present apparatus, the coiled long substrate
2001
is mounted on a substrate feeding roller
2002
. While an interleaving paper inserted for surface protection is wound up on a interleaf wind-up roller
2003
, the substrate is transported as indicated by an arrow
2004
toward a substrate wind-up roller
2062
and wound thereon as indicated by an arrow
2061
.
In the transporting path, the substrate
2001
passes through a tension detecting roller
2005
and an electric power supplying roller
2006
an enters and electrodeposition vessel
2009
. In the vessel
2009
, the substrate
2001
is positioned by supporting rollers
2013
and
2014
and is subjected to the formation of an oxide film by electrodeposition.
After passing the electrodeposition vessel
2009
, the substrate
2001
is introduced into a rinsing vessel
2030
and washed therein. The substrate is positioned in the rinsing vessel
2030
by supporting rollers
2031
and
2066
. After passing the rinsing vessel
2030
, the substrate
2001
is introduced into a hot air drying oven
2051
and dried therein.
After passing the drying oven
2051
, the substrate
2001
passes through a supporting roller
2057
, then is subjected to the correction of lateral displacement by a skew correcting roller
2059
and is wound on the substrate wind-up roller
2062
together with a new interleaving paper supplied from an interleaf feeding roller
2060
. Then the substrate is transported to a next step when required.
The tension detecting roller
2005
detects the dynamic tension of the substrate
2001
and applies a feedback to braking means such as a powder clutch (not shown in the drawings) linked to the shaft of the substrate feeding roller
2002
, thereby maintaining a constant tension. Thus, the transporting path of substrate
2001
is designed so as to have a predetermined tension value between the supporting rollers.
In particular, in the present apparatus in which the film forming surface of the substrate is free from contact with the rollers, weak tension may result in various defects such as disengagement of the substrate
2001
from the supporting rollers or hanging of the substrate
2001
at the entrance or exit of the electrodeposition vessel
2009
or the rinsing vessel
2030
, leading to the damage on the substrate by frictional contact thereof. Consequently the tension detecting roller
2005
is an important member.
The configuration in which the apparatus does not contact the film forming surface has the advantages that the film forming surface is free from damage or smear and is particularly advantageous for an application in which irregularities in size on the order of several microns have to be formed on a thin film, as in the case of the reflection film of a solar cell.
An electric power supplying roller
2006
for serving to supply a cathodic potential to the long substrate is positioned as close as possible to the electrodeposition bath and is connected to the negative electrode of a power source
2008
.
The electrodeposition vessel
2009
serves to hold the electrodeposition bath
2016
, to determine the path of the substrate
2001
and to support an anode
2017
so as to oppose to the substrate
2001
. The anode
2017
is connected via an electric power supplying bar
2015
to the positive electrode of the power source
2008
, and a positive voltage is applied to the anode
2017
. Thus there is executed an electrochemical electrodeposition process in the electrodeposition bath, with the substrate
2001
as the negative side and the anode
2017
as the positive side.
When the electrodeposition bath
2016
is maintained at a high temperature, there is generated a considerable amount of water vapor and vapor exhausting dusts
2010
,
2011
and
2012
are used to remove the water vapor.
Also, in order to agitate the electrodeposition bath
2016
, air is introduced from an agitating air introduction pipe
2019
and bubbling is executed by blowing air from an air blow pipe
2018
in the electrodeposition vessel
2009
.
For supplying a high temperature bath to the electrodeposition vessel
2009
, a heater
2024
is provided in an electrodeposition circulating vessel
2025
for heating an electrodeposition bath solution and the heated solution is supplied to the electrodeposition vessel through a circulating pump
2023
and an electrodeposition bath solution supply pipe
2020
. The solution overflowing from the electrodeposition vessel
2009
and a part of the solution to be positively circulated are returned through a feedback path (not shown in the drawings) to the circulating vessel
2025
and are heated again therein.
In case the discharge amount of the pump
2023
is constant, the amount of the solution supplied from the circulating vessel
2025
to the electrodeposition vessel
2009
can be controlled by valves
2021
and
2022
. In order to increase the supply amount, the valve
2021
is opened more while the valve
2022
is closed more, and vice versa. The level of the electrodeposition bath
2016
is adjusted by such a supply amount and the feedback amount from the feedback bath.
The circulating vessel
2025
is provided with a filter circulating system consisting of a circulating pump
2027
and a filter, in order to remove particles in the circulating vessel
2025
. If the supply and feedback amounts of the solution between the circulating vessel
2025
and the electrodeposition vessel
2009
are sufficiently large, satisfactory removal of the particles can be achieved by positioning the filter solely in the circulating vessel
2025
.
In the present apparatus, the circulating vessel
2025
is also provided with a vapor exhausting duct
2026
for removing the vapor. Since the circulating vessel
2025
constitutes a heat source by arranging the heater
2024
therein, there is generated a significant amount of vapor and such vapor removal is very effective in case unexpected release or condensation of thus generated vapor is undesirable.
An electrodeposition reserve vessel
2029
is provided for preventing damage to a solution disposing unit which is caused by direct discharge of the heated solution to the solution disposing system, and can hold the electrodeposition bath
2016
of the electrodeposition vessel
2009
when the valve
2028
is opened, thereby evacuating the electrodeposition vessel
2009
and improving the efficiency of the work therein.
The substrate
2001
subj
Arao Kozo
Miyamoto Yusuke
Sonoda Yuichi
Toyama Noboru
Nguyen Nam
Nicolas Wesley A.
LandOfFree
Electrodeposition method of forming an oxide film does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrodeposition method of forming an oxide film, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrodeposition method of forming an oxide film will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2941405