U.S. patent application number 14/357810 was filed with the patent office on 2014-12-11 for high speed horizontal electroforming apparatus for manufacturing metal foil and method for manufacturing metal foil.
The applicant listed for this patent is POSCO. Invention is credited to Un-Kwan Cho, Jae-Hun Choi, Seok-Hwan Choi, Hong-Joon Kim, Jin-You Kim, Sung-Jool Kim, Jae-Kon Lee.
Application Number | 20140360882 14/357810 |
Document ID | / |
Family ID | 48429873 |
Filed Date | 2014-12-11 |
United States Patent
Application |
20140360882 |
Kind Code |
A1 |
Kim; Hong-Joon ; et
al. |
December 11, 2014 |
HIGH SPEED HORIZONTAL ELECTROFORMING APPARATUS FOR MANUFACTURING
METAL FOIL AND METHOD FOR MANUFACTURING METAL FOIL
Abstract
The present invention relates to an apparatus and a method for
manufacturing metal foil by electroforming. Provided is a
horizontal electroforming apparatus comprising: base plate supply
means for continuously supplying flexible and conductive base
plates to be provided as cathode electrodes in one horizontal
direction; a horizontal cell including a conductor roll which
contacts a widthwise edge portion of the base plate to transfer the
base plate and supply current to the base plate, anode electrodes
arranged at one side of the base plate or spaced apart from each
other at both respective sides of the base plate, an electrolyte
supply device for supplying an electrolyte containing metal ion
through a horizontal path formed by the base plates and the anode
electrodes, and current supply devices arranged at one side or both
sides of the base plate to supply current to the conductor roll and
to the anode electrodes so as to enable electroseparation of the
metal ion; and delaminating means for delaminating, from the base
plate, metal foil electrodeposited at one side or both sides of the
base plate.
Inventors: |
Kim; Hong-Joon; (Pohang-si,
KR) ; Kim; Jin-You; (Pohang-si, KR) ; Lee;
Jae-Kon; (Pohang-si, KR) ; Choi; Jae-Hun;
(Pohang-si, KR) ; Kim; Sung-Jool; (Pohang-si,
KR) ; Choi; Seok-Hwan; (Pohang-si, KR) ; Cho;
Un-Kwan; (Pohang-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
POSCO |
Pohang-si, Gyeongsangbuk-do |
|
KR |
|
|
Family ID: |
48429873 |
Appl. No.: |
14/357810 |
Filed: |
November 15, 2012 |
PCT Filed: |
November 15, 2012 |
PCT NO: |
PCT/KR2012/009684 |
371 Date: |
May 13, 2014 |
Current U.S.
Class: |
205/77 ;
204/203 |
Current CPC
Class: |
C25D 1/04 20130101; C25D
1/00 20130101; C25D 1/20 20130101 |
Class at
Publication: |
205/77 ;
204/203 |
International
Class: |
C25D 1/04 20060101
C25D001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 15, 2011 |
KR |
10-2011-0118664 |
Nov 15, 2011 |
KR |
10-2011-0118665 |
Nov 15, 2011 |
KR |
10-2011-0118667 |
Claims
1. A horizontal electroforming apparatus comprising: a base sheet
supply device configured to continuously supply a flexible and
conductive base sheet functioning as a cathode in one direction; a
horizontal cell comprising conduct rolls configured to apply a
current to the base sheet while making contact with lateral edges
of the base sheet and moving the base sheet, anodes spaced apart
from one or both sides of the base sheet, an electrolyte supply
device configured to supply an electrolyte containing metal ions to
a horizontal passage formed by the base sheet and the anodes, and a
current supply device configured to supply a current to the conduct
rolls and the anodes to cause electro-precipitation of the metal
ions on one or both sides of the base sheet; and a stripping device
configured to strip metal foil electro-deposited on one or both
sides of the base sheet from the base sheet.
2. The horizontal electroforming apparatus of claim 1, wherein the
electrolyte supply device comprises an electrolyte supply nozzle
configured to supply an electrolyte to one or both sides of the
base sheet in the same direction as a moving direction of the base
sheet, a direction opposite to the moving direction of the base
sheet, or both directions.
3. The horizontal electroforming apparatus of claim 1, wherein a
plurality of horizontal cells are provided, and the plurality of
horizontal cells are arranged linearly, in a moving direction of
the base sheet.
4. The horizontal electroforming apparatus of claim 1, further
comprising a heat treatment device configured to perform a heat
treatment such as induction heating, atmosphere heating, or direct
heating on the metal foil electro-deposited on the base.
5. The horizontal electroforming apparatus of claim 1, wherein the
stripping device comprises a plurality of rollers capable of
causing a difference in shear force between the base sheet and the
metal foil.
6. The horizontal electroforming apparatus of claim 1, wherein each
of the anodes has a thickness decreasing from a center to edges
thereof in a width direction of the base sheet.
7. The horizontal electroforming apparatus of claim 1, wherein an
edge mask is disposed in the horizontal cell to prevent
electro-precipitation of metal ions on the lateral edges of the
base sheet.
8. The horizontal electroforming apparatus of claim 1, wherein each
of the anodes is divided into a plurality of sub electrodes in a
width direction or in a moving direction of the base sheet.
9. The horizontal electroforming apparatus of claim 8, wherein the
sub electrodes have different sizes.
10. The horizontal electroforming apparatus of claim 9, wherein
different currents are supplied to the sub electrodes.
11.-13. (canceled)
14. The horizontal electroforming apparatus of claim 3, wherein the
electrolyte supply nozzle is inclined or curved to supply an
electrolyte in a electrolyte-flow direction.
15. The horizontal electroforming apparatus of claim 14, wherein at
least an end portion of the electrolyte supply nozzle is separable,
to supply an electrolyte in forward and backward directions
relative to the moving direction of the base sheet.
16. The horizontal electroforming apparatus of claim 14, wherein
the end portion has a sectional shape similar to the shape of a de
Laval nozzle.
17. A method for manufacturing metal foil, the method comprising:
supplying an electrolyte containing metal ions to a surface of a
flexible and conductive base sheet which functions as a cathode and
is horizontally fed in one direction; forming an electro-deposition
layer on one or both sides of the base sheet through
electro-precipitation of the metal ions of the electrolyte on one
or both sides of the base sheet, the electro-precipitation of the
metal ions being caused by the base sheet and anodes spaced apart
from one or both sides of the base sheet; and stripping the
electro-deposition layer from the base sheet as metal foil.
18. The method of claim 17, wherein one or both sides of the base
sheet are coated with oxide films.
19. The method of claim 17, wherein the stripped metal foil is
heat-treated at 300.degree. C. to 600.degree. C.
20. The method of claim 17, wherein the electrolyte is supplied to
a horizontal passage formed between the base sheet and the anodes
in the same direction as a moving direction of the base sheet and a
direction opposite to the moving direction of the base sheet.
21. The method of claim 17, wherein different electrolytes are
supplied to both the sides of the base sheet.
22. The method of claim 17, wherein prior to the stripping of the
electro-deposition layer, the method further comprises: secondarily
supplying an electrolyte; and secondarily forming an
electro-deposition layer.
23. The method of claim 22, wherein different electrolytes are
supplied in the supplying of the electrolyte and the secondary
supplying of the electrolyte.
24. The method of claim 23, wherein the metal foil has a
multi-layer structure.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a method and apparatus for
manufacturing metal foil at high speed, and particularly, to a
method for continuously manufacturing metal foil by electroforming
and an apparatus used in the method.
BACKGROUND ART
[0002] In general, a rolling method and an electroforming method
are both widely used methods for manufacturing metal foil. In the
rolling method, metal slabs manufactured through iron making, steel
making, and continuous casting are rolled into foil, and in the
electroforming method, copper foil is manufactured using a drum
cell.
[0003] In a most common process for manufacturing thin plates using
a rolling method, slabs may be reheated and hot-rolled into metal
plates having a thickness of several millimeters (mm), and such
hot-rolled thin plates may be additionally cold-rolled into very
thin foil having a thickness of 100 .mu.m or less. U.S. Pat. No.
4,948,434 discloses such a method of manufacturing metal foil. In
the disclosed method, cold rolling and annealing are performed
repeatedly. Thus, the disclosed method has problems such as complex
processes requiring large amounts of energy and time, difficulties
in forming constant shapes, thickness deviations, non-uniform
surface roughness, edge cracking, high manufacturing costs, and
difficulties in manufacturing wide metal foil.
[0004] Recently, processes and apparatuses for manufacturing metal
foil (copper foil) by an, electroforming method have been
researched. For example, Korean Patent Application Laid-open. Nos.
1999-0064747 and 2004-0099972 disclose methods and apparatuses for
manufacturing metal foil by electroforming. Metal foil can be
manufactured through simple processes by using such methods.
[0005] In the patent documents, methods of manufacturing metal foil
using a drum cell are disclosed. When metal foil is manufactured by
an electroforming method using a drum cell, the surface of the drum
cell is carefully treated and maintained to obtain metal foil
having a uniform thickness and surface roughness. Thus, processes
may be suspended for checking or repairing the surface of the drum
cell. In other words, the surface of the drum cell may not be
continuously managed.
[0006] Moreover, the rate of metal foil production by
electroforming is affected by the surface area of a drum cell
dipped into an electrolyte. That is, the rate of production is
limited by the size of the drum cell. However, if a large drum cell
is used, manufacturing costs are increased, and it may be difficult
to replace the large drum cell. In addition, although the rate of
production can be increased by increasing the velocity of an
electrolyte at a gap between an anode and a cathode, it is
difficult to increase the velocity of the electrolyte because the
velocity of the electrolyte is gradually decreased due to a curved
gap between the anode and the cathode.
DISCLOSURE
Technical Problem
[0007] An aspect of the present disclosure may include a method and
apparatus for manufacturing metal foil with high productivity by an
electroforming method using a horizontal cell.
[0008] An aspect of the present disclosure may also provide an
electroforming method and apparatus for manufacturing metal foil
with high productivity and at low cost by supplying an electrolyte
at high speed to form electro-deposition layers on upper and lower
sides of a base sheet.
[0009] An aspect of the present disclosure may also provide an
electroforming method and apparatus for manufacturing metal foil
through a continuous process using any metal usable for
electro-deposition.
[0010] As aspect of the present disclosure may also provide an
apparatus for manufacturing metal foil having a uniform
composition, surface texture, and thickness, by forming a uniform
current density between an anode and a cathode.
[0011] An aspect of the present disclosure may also provide a
horizontal electroforming apparatus configured to improve
productivity by stabilizing a flow field of an electrolyte supplied
at high speed and preventing vortexes.
Technical Solution
[0012] According to an aspect of the present disclosure, a
horizontal electroforming apparatus may include: a base sheet
supply device configured to continuously supply a flexible and
conductive base sheet functioning as a cathode in one direction; a
horizontal cell including conduct rolls configured to apply a
current to the base sheet while making contact with lateral edges
of the base sheet and moving the base sheet, anodes spaced apart
from one or both sides of the base sheet, an electrolyte supply
device configured to supply an electrolyte containing metal ions to
a horizontal passage formed by the base sheet and the anodes, and a
current supply device configured to supply a current to the conduct
rolls and the anodes to cause electro-precipitation of the metal
ions on one or both sides of the base sheet; and a stripping device
configured to strip metal foil electro-deposited on one or both
sides of the base sheet from the base sheet.
[0013] The electrolyte supply device includes an electrolyte supply
nozzle configured to supply an electrolyte to one or both sides of
the base sheet in the same direction as a moving direction of the
base sheet, a direction opposite to the moving direction of the
base sheet, or both directions.
[0014] A plurality of horizontal cells may be provided, and the
plurality of horizontal cells may be arranged linearly, in a moving
direction of the base sheet.
[0015] The horizontal electroforming apparatus may further include
a heat treatment device configured to perform a heat treatment such
as induction heating, atmosphere heating, or direct heating on the
metal foil electro-deposited on the base.
[0016] The stripping device may include a plurality of rollers
capable of causing a difference in shear force between the base
sheet and the metal foil.
[0017] An edge mask may be disposed in the horizontal cell to
prevent electro-precipitation of metal ions on the lateral edges of
the base sheet.
[0018] Each of the anodes may have thickness decreasing from a
center to edges thereof in a width direction of the base sheet.
[0019] Each of the anodes may be divided into a plurality of sub
electrodes in a width direction of the base sheet, and the sub
electrodes may have different sizes. In addition, different
currents may be supplied to the sub electrodes.
[0020] Each of the anodes may be divided into a plurality of sub
electrodes in a moving direction of the base sheet, and the sub
electrodes may have different sizes. In addition, different
currents may be supplied to the sub electrodes.
[0021] The electrolyte supply nozzle may be inclined or curved to
supply an electrolyte in a electrolyte-flow direction. In this
case, at least an end portion of the electrolyte supply pipe is
separable to supply an electrolyte in forward and backward
directions relative to the moving direction of the base sheet. The
end portion may have a sectional shape similar to the shape of a de
Laval nozzle.
[0022] According to another aspect of the present disclosure, a
method for manufacturing metal foil may include: supplying an
electrolyte containing metal ions to a surface of a flexible and
conductive base sheet which functions as a cathode and is
horizontally fed in one direction; forming an electro-deposition
layer on one or both sides of the base sheet through
electro-precipitation of the metal ions of the electrolyte on one
or both sides of the base sheet, the electro-precipitation of the
metal ions being caused by the base sheet and anodes spaced apart
from one or both the sides of the base sheet; and stripping the
electro-deposition layer from the base sheet as metal foil.
[0023] One or both sides of the base sheet may be coated with oxide
films.
[0024] The stripped metal foil may be heat-treated at 300.degree.
C. to 600.degree. C.
[0025] The electrolyte may be supplied to a horizontal passage
formed between the base sheet and the anodes in the same direction
as a moving direction of the base sheet and a direction opposite to
the moving direction of the base sheet.
[0026] Different electrolytes may be supplied to both the sides of
the base sheet.
[0027] Prior to the stripping of the electro-deposition layer, the
method may further include: secondarily supplying an electrolyte;
and secondarily forming an electro-deposition layer. Different
electrolytes may be supplied in the supplying of the electrolyte
and the secondary supplying of the electrolyte. The metal foil may
be formed to have a multi-layer structure.
Advantageous Effects
[0028] According to an embodiment of the present disclosure, metal
foil may be manufactured at a high rate.
[0029] According to another embodiment of the present disclosure,
metal foil having improved surface roughness on both sides thereof,
a uniform composition, and a uniform thickness may be manufacturing
at a high rate.
[0030] According to another embodiment of the present disclosure,
the thickness of metal foil may be controlled through a continuous
process, or metal foil having a multi-layer structure may be
manufacturing through a continuous process.
[0031] According to another embodiment of the present disclosure,
different types of metal foil may be simultaneously
manufactured.
[0032] According to another embodiment of the present disclosure,
although an electrolyte is supplied to a base sheet at high speed,
vibration of the base sheet may be structurally suppressed to allow
the electrolyte to form a uniform flow field and thus to induce
stable electro-precipitation. Therefore, high-quality metal foil
having a uniform composition, surface, and thickness may be
manufactured.
[0033] According to another embodiment of the present disclosure,
an electro-precipitation region may be increased, and thus metal
foil may be manufactured with high productivity.
[0034] By using the horizontal electroforming apparatus according
to an embodiment of the present disclosure, metal foil having a
uniform composition, surface texture, and thickness in a width
direction thereof may be manufacturing at a high rate.
[0035] Furthermore, since the horizontal electroforming apparatus
is configured to structurally prevent non-uniform current density
in a width direction, high-quality metal foil may be manufactured
with improved productivity.
[0036] Furthermore, according to an embodiment of the present
disclosure, current density may be controlled in the moving
direction of a base sheet to form an entirely uniform
electro-deposition layer.
DESCRIPTION OF DRAWINGS
[0037] FIG. 1 is a schematic view illustrating an apparatus for
manufacturing metal foil according to an embodiment of the present
disclosure.
[0038] FIG. 2 is a schematic view illustrating the apparatus for
manufacturing metal foil according to another embodiment of the
present disclosure.
[0039] FIG. 3 is a view illustrating anodes each divided in the
width direction of a base sheet and having a thickness decreasing
from the center to lateral edges thereof, according to an
embodiment of the present disclosure.
[0040] FIG. 4 is a schematic view illustrating anodes divided in a
moving direction of a base sheet according to an embodiment of the
present disclosure.
[0041] FIG. 5 is a schematic view illustrating a horizontal cell
including inclined electrolyte supply nozzles according to an
embodiment of the present disclosure.
[0042] FIG. 6 is a schematic view illustrating a horizontal cell
including curved electrolyte supply nozzles according to an
embodiment of the present disclosure.
[0043] FIG. 7 is a cross-sectional view illustrating a de Laval
nozzle formed on an end of an electrolyte supply pipe according to
another embodiment of the present disclosure.
[0044] FIG. 8 is a view illustrating a horizontal electroforming
apparatus in which a plurality of horizontal cells are arranged
linearly, according to another embodiment of the present
disclosure.
[0045] FIG. 9 is a graph showing a current density curve of a
horizontal electroforming apparatus including a horizontal cell in
which anodes each having a thickness decreasing from the center to
lateral edges thereof as shown in FIG. 3 are disposed, and a
current density curve of a drum type electroforming apparatus
including a drum cell of the related art.
[0046] FIGS. 10A to 10C are schematic views illustrating distal end
structures of electrolyte supply nozzles used in Example 2. FIG.
10A illustrating an right-angled nozzle, FIGS. 10B and 10C
illustrating curved nozzles according to embodiments of the present
disclosure.
[0047] FIGS. 11A to 11C are views illustrating streamlines of flow
fields of an electrolyte supplied under a laminar flow condition
through the electrolyte supply nozzles shown in FIGS. 10A to
10C.
[0048] FIGS. 12A to 12C are views illustrating streamlines of flow
fields of an electrolyte supplied under a turbulent flow condition
through the electrolyte supply pipes shown in FIGS. 10A to 10C.
BEST MODE
[0049] Embodiments of the present disclosure provide a horizontal
cell electroforming apparatus and a method for manufacturing metal
foil by electro-depositing a metal on a base sheet fed horizontally
in the electroforming apparatus. The embodiments of the present
disclosure will now be described in detail with reference to the
accompanying drawings. The disclosure may, however, be exemplified
in many different forms and should not be construed as being
limited to the specific embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be thorough
and complete, and will fully convey the scope of the disclosure to
those skilled in the art. In the drawings, the shapes and
dimensions of elements may be exaggerated for clarity.
[0050] A horizontal electroforming apparatus 100 will now be
described with reference to FIGS. 1 and 2 according to an aspect of
the present disclosure. FIGS. 1 and 2 are schematic views
illustrating the horizontal electroforming apparatus 100 according
to embodiments of the present disclosure.
[0051] In the embodiments of the present disclosure, the horizontal
electroforming apparatus 100 includes a base sheet supply device
10, a horizontal cell 30 (also referred to as an electroforming
cell 30), an electrolyte supply device, and a metal foil stripping
device.
[0052] The base sheet supply device 10 supplies a base sheet 11 to
the inside of the electroforming cell 30. Base sheets 11 having a
predetermined size may be fed on after another, or a base sheet 11
may be continuously fed. In a non-limiting example, a base sheet 11
wound in the form of a coil may be continuously fed into the
horizontal cell 30. After the base sheet 11 is fed, another coiled
base sheet 11 may be continuously fed.
[0053] In this case, the rear edge of the base sheet 11 may be
bonded to the front edge of the next base sheet 11 by a method such
as welding so as to continuously supply the base sheets 11 to the
inside of the horizontal cell 30. The edges of the base sheets 11
may be shaped into predetermined patterns for easily joining the
edges.
[0054] Furthermore, a base sheet 11 having a uniform surface
roughness may be used because the surface roughness of the base
sheet 11 will be transferred (copied) to electro-deposition layers
to be formed on the base sheet 11. A base sheet 11 having a uniform
surface roughness may be obtained by polishing. Therefore, a
polishing machine may be used to obtain base sheets 11 having
proper surface roughness. If a base sheet 11 is polished to a
desired degree of surface roughness as described above, the degree
of surface roughness may be transferred from the base sheet 11 to
metal foil 50 during an electroforming process, and thus the metal
foil 50 may have an equivalent degree of surface roughness.
[0055] The surface roughness of a base sheet 11 may be adjusted by
any method, such as chemical, mechanical, or chemical and
mechanical polishing methods known in the related art. For example,
mechanical polishing, chemical polishing such as etching, or
chemical mechanical polishing (CMP) may be used.
[0056] When metal foil 50 is manufactured by an electroforming
method, the quality of the metal foil 50 may be significantly
affected by the surface roughness thereof. For example,
electro-deposition layers (metal foil 50) deposited on a base sheet
11 may have surface roughness transferred from the base sheet 11,
and thus a short circuit occurring in a defective portion
(roughness defect) of the metal foil 50 may damage the surface of
the base sheet 11 and thus may cause non-uniform electro-deposition
and surface defects. The surface roughness of a base sheet 11 may
be adjusted according to the use of metal foil 50 to be formed. For
example, if metal foil 50 for substrates of display devices are
formed, a base sheet 11 polished to a surface roughness of 4 nm or
less may be used, and if metal foil 50 for substrates of solar
cells, a base sheet 11 polished to a surface roughness of 40 nm or
less may be used.
[0057] When a base sheet 11 is polished as described above,
materials such as abrasives, polishing liquids, or removed
particles may remain on the base sheet 11, and thus a cleaning
process may be necessary. To this end, the horizontal
electroforming apparatus 100 of the embodiments of the present
disclosure may include a pre-cleaning device. The surfaces of the
base sheet 11 may be cleaned with an acid solution such as a
diluted hydrochloric acid solution or a diluted sulfuric acid
solution, and water.
[0058] In addition, a drying device (not shown) may be used to dry
the base sheet 11 after cleaning. The base sheet 11 may be dried by
blowing compressed air or high-temperature gas onto the base sheet
11, or heating the base sheets 11.
[0059] In the embodiments of the present disclosure, when metal
foil 50 is formed by electroforming, any base sheet 11 may be used
as long as the base sheet 11 is flexible and conductive. For
example, a base sheet 11 formed of stainless steel or titanium may
be used.
[0060] In the embodiments of the present disclosure, during a
manufacturing process, if metal foil 50 is electro-deposited on a
base sheet 11 and strongly adhered thereto, it may be difficult to
separate the metal foil 50 from the base sheet 11. Therefore, oxide
films may be previously formed on the base sheet 11. Then,
electro-deposition layers (metal foil 50) formed on the base sheet
11 may easily separated because oxide films formed on the base
sheet 11 may lower the adhesion between the metal foil 50 and the
base sheets 11.
[0061] In the horizontal electroforming apparatus 100 of the
embodiments of the present disclosure, the horizontal cell 30 is
separated from the base sheet supply device 10 and used to
electro-deposit a metal on a base sheet 11.
[0062] In the embodiments of the present disclosure, a base sheet
11 is continuously fed into the electroforming cell (horizontal
cell 30) in a fixed direction. Herein, the `electroforming cell 30
(horizontal cell 30)` may be defined as a unit cell in which an
electrolyte is supplied to a base sheet 11 so as to electro-deposit
metal layers on the base sheet 11 by an electro-precipitation
reaction between metal ions and the base sheet 11. In addition, the
expression `fixed direction` is used herein to refer to that the
moving direction of base sheets 11 fed into the electroforming cell
30 is not changed at least until the base sheets 11 depart from the
electroforming cell 30. That is, in the present disclosure, the
moving direction of a base sheet 11 is expressed as a horizontal
direction or horizontal, and for this reason, the electroforming
cell 30, into which base sheet 11 is fed in the horizontal
direction to cause metal deposition thereon by an
electro-precipitation reaction of metal ions of an electrolyte, may
be referred to as a horizontal cell.
[0063] In a drum type electroforming apparatus of the related art,
an electrolyte is contaminated by residues remaining after a drum
is polished to obtain a desired degree of surface roughness.
However, since the horizontal cell 30 is separated from the base
sheet supply device 10 in the embodiments of the present
disclosure, this problem may be prevented. Furthermore, in a drum
type electroforming apparatus of the related art, if it is
necessary to replace a base sheet, a drum is replaced together with
the base sheet, and thus manufacturing costs are increased.
However, according to the embodiments of the present disclosure, a
base sheet 11 can only be replaced, and thus manufacturing costs
can be reduced.
[0064] The horizontal cell 30 includes: conduct rolls 31 and 31'
configured to convey a base sheet 11 and connect cathodes to a
power source; anodes 32 spaced a constant distance from one or both
sides of the base sheet 11; a current supply device 33, configured
to supply a current (negative (-) charge) to the conduct rolls 31
and 31' and a current (positive (+) charge) to the anodes 32; and
an electrolyte supply device containing an electrolyte for causing
an electrolyte reaction.
[0065] The conduct rolls 31 and 31' function as conveying units to
move a base sheet 11 into the horizontal cell 30 and out of the
horizontal cell 30, and function as connectors connecting the base
sheet 11 functioning as a cathode to the current supply device 33
so as to cause an electrolyte reaction between the anodes 32 and
the base sheet 11 and thus to induce precipitation of metal ions on
the base sheet 11. The conduct rolls 31 and 31' may make contact
with lateral edge portions of a base sheet 11 to move the base
sheet 11 into the horizontal cell 30 and out of the horizontal cell
30.
[0066] In the embodiments of the present disclosure, since a
flexible and conductive base sheet 11 is used, the base sheet 11
may be subject to deflection due to the weight thereof. In this
case, the distances between the base sheet 11 and the anodes 32 may
be varied, and this current density may not be uniform. As a
result, metal foil 50 having a uniform thickness may not be
produced. The conduct rolls 31 disposed at an entrance side and the
conduct rolls 31' disposed at an exit side may be rotated at
different speeds so as to prevent deflection of a base sheet 11.
That is, if the exit conduct rolls 31' are rotated faster than the
entrance conduct rolls 31, deflection of a base sheet 11 caused by
the weight of the conduct rolls 31 may be prevented.
[0067] The anodes 32 are spaced a constant distance apart from a
base sheet 11 passing through the horizontal cell 30. Thus, flow
passages for an electrolyte are formed between the anodes 32 and
the base sheet 11.
[0068] An electrolyte may be uniformly supplied to a base sheet 11
in the width direction of the base sheet 11 for uniform current
density and production of metal foil 50 having a uniform thickness.
However, when an electrolyte is supplied to a base sheet 11 through
electrolyte supply pipes 35, the electrolyte may be concentrated on
lateral edge portions of the base sheet 11 to cause a non-uniform
current density in the width direction of the base sheet 11. In
this case, defective metal foil 50 having a non-uniform thickness
in width direction may be produced. Therefore, a method or device
may be necessary to form a uniform current density in the width
direction of a base sheet 11. For example, edge masks may be used
to prevent a locally high current density and thus the formation of
electro-deposition layers having a non-uniform thickness.
[0069] In addition, the thickness of each of the anodes 32 may be
reduced from the center to lateral edges thereof. In this case, the
gaps between the anodes 32 and a base sheet 11 functioning as a
cathode may be increased in directions toward lateral edges, and
thus a locally high current density caused by the concentration of
an electrolyte may be offset by the outwardly decreasing
thicknesses of the anodes 32. In this way, electro-deposition on a
base sheet 11 may be controlled.
[0070] For example, as shown in FIG. 3, the anodes 32 may have
thicknesses continuously decreasing in a curved shape in directions
from the center to the lateral edges of a base sheet 11 (in this
case, the anodes may be referred as curved anodes 32a). The curved
anodes 32a may not have a constant curvature. The curved anodes 32a
having thicknesses varying in the width direction of a base sheet
11 may prevent a localized high current density at edge portions of
the base sheet 11 caused by an electrolyte concentrating on the
edge portions, and thus the speed and composition of metal
precipitation may be uniform between the curved anodes 32a and the
base sheet 11 functioning as a cathode. Therefore, metal foil 50
may not have surface defects caused by a non-uniform current
density in a width direction.
[0071] Although current density can be uniformly maintained using
the curved anodes 32a thicker at the centers than the edges
thereof, each of the anodes 32 may be divided into plurality of sub
electrodes in the width direction thereof as shown in FIG. 3 for
more uniform current density (in this case, the anodes 32a may be
referred to as width-division anodes 32a). The sub electrodes of
the width-division anodes 32a may have the same width or different
widths. In addition, some of the sub electrodes of the
width-division anodes 32a may have different sizes, and the other
of the parts may have the same size. Referring to FIG. 2, the
anodes 32a are curved and divided in the width directions thereof.
However, the embodiments of the present disclosure are not limited
thereto. For example, anodes only curved or anodes only divided may
be used.
[0072] Since currents to the sub electrodes of the width-division
anodes 32a can be individually controlled, current density
uniformity may be maintained more precisely. That is, if currents
from the current supply device 33 to the sub electrodes of the
width-division anodes 32a are individually controlled according to
a desired amount of electro-deposition in the width direction, the
amount of a metal electro-deposited on a base sheet 11 may be
uniformly controlled in the width direction, and thus metal foil 50
having a uniform thickness may be obtained.
[0073] Furthermore, in the embodiments of the present disclosure,
the anodes 32 may be divided into sub electrodes in the moving
direction of a base sheet 11 (in this case, the anodes 32 may be
referred as front-to-back division anodes 32b). For example, the
width-division anodes 32a may also be divided in the moving
direction of a base sheet 11. Like the width-division anodes 32a,
the sub electrodes of the front-to-back division anodes 32b may
have different sizes, and currents to the sub electrodes of the
front-to-back division anodes 32b may be individually
controlled.
[0074] When a base sheet 11 is fed in the horizontal cell 30,
initial electro-deposition of a metal may function as
electro-deposition nuclei for the next electro-deposition, and thus
electro-deposition may occur continuously and stably. Furthermore,
although an electrolyte is supplied at high speed,
electro-deposition layers may not be striped or separated.
[0075] The rate of electro-deposition is affected by the flow rate
of an electrolyte, the feeding speed of a base sheet 11, and the
relative velocities thereof. In the embodiments of the present
disclosure, an electrolyte may be supplied in the same direction as
the moving direction of a base sheet 11, the opposite direction to
the moving direction of the base sheet 11, or both directions. For
example, in a region in whdch an electrolyte is supplied in the
opposite direction to the moving direction of a base sheet 11, the
rate of electro-deposition may be low because the electrolyte and
the base sheet 11 make contact with each other for a relatively
short period of time. In this case, anodes 32 divided into sub
electrodes in the moving direction of the base sheet 11 may be used
to increase the rate of electro-deposition by applying different
currents to the sub electrodes of the anodes 32.
[0076] Furthermore, in a region in which an electrolyte is supplied
in the same direction as the moving direction of a base sheet 11,
the rate of electro-deposition may be high because the electrolyte
and the base sheet 11 make contact with each other for a relatively
long period of time. However, the rate of electro-deposition may be
gradually reduced because the concentration of metal ions of the
electrolyte may be gradually reduced. In this case, like in the
former case, anodes 32 divided into sub electrodes in the moving
direction of the base sheet 11 may be used to increase the rate of
electro-deposition by applying different currents to the sub
electrodes of the anodes 32.
[0077] In addition, the anodes 32 may have thicknesses decreasing
in directions from the centers to the lateral edges thereof and may
be divided into sub electrodes in the width and length directions
thereof. In this case, the current densities of regions
corresponding to the sub electrodes of the anodes 32 may be
individually controlled, and thus metal foil 50 having a more
uniform thickness may be obtained.
[0078] As described above, when an electrolyte reaction occurs
between an electrolyte and a base sheet 11 functioning as a
cathode, metal ions included in the electrolyte are
electro-deposited on the base sheet 11 (electro-precipitation of
metal ions). Therefore, if the electrolyte is supplied at high
speed, more metal ions may be electro-deposited on the base sheet
11 at a high electro-deposition rate.
[0079] In a drum cell type electroforming apparatus of the related
art, an electrolyte flows in a curved flow passage because a base
sheet is curved according to the curvature of a drum cell, and thus
the velocity of the electrolyte is gradually decreased to lower the
rate of electro-deposition. Thus, metal foil 50 manufactured using
the drum type electroforming apparatus may have a non-uniform
thickness.
[0080] However, according to the embodiments of the present
disclosure, since the horizontal cell 30 is used, an electrolyte
may flow in a horizontal flow passage, and thus the electrolyte may
be supplied at a high flow rate without a decrease in velocity.
Therefore, the rate of electro-deposition of metal ions may be
increased. An electrolyte may be supplied at a maximum velocity of
5,000 in Reynolds number, and the velocity of the electrolyte may
be increased or decreased relatively to the feeding speed of a base
sheet 11. In addition, according to the state of
electro-deposition, the electrolyte may be supplied within a
laminar-flow velocity range (in which streamlines of the
electrolyte are straight without turbulence), and after
electro-deposition is stabilized, the electrolyte may be rapidly
supplied within a turbulent-flow velocity range (in which
streamlines of the electrolyte fluctuate to the left and
right).
[0081] If the velocity of an electrolyte is high at an initial
stage of electro-deposition, an electro-deposition layer may be
stripped from a base sheet 11 to cause an electro-deposition fail,
and thus after the electro-deposition layer is grown to a thickness
of several micrometers and thus can securely adhere to the base
sheet 11 owing to stress accumulated therein, the velocity of the
electrolyte may be increased to form a high-velocity flow field.
However, when forming a high-velocity flow field, the velocity of
the electrolyte may be controlled not to increase to a level
cancelling out the surface tension between the electro-deposition
layer and the base sheet 11. That is, if the velocity of the
electrolyte is increased to a certain level, the shearing stress
between a flow field formed by the electrolyte and the
electro-deposition layer becomes greater than the surface tension
between the electro-deposition layer and the base sheet 11, and
thus the electro-deposition layer may be stripped.
[0082] The current supply device 33 is used to supply a negative
(-) current to the conduct rolls 31 and 31' and a positive (+)
current to the anodes 32. The current supply device 33 is not
limited to a particular type. For example, a general type of
current supply device may be used as the current supply device 33.
Thus, a detailed description of the current supply device 33 will
not be given.
[0083] An electrolyte may be supplied to a side of a base sheet 11
fed into the horizontal cell 30 to form metal foil on the side of
the base sheet 11 by causing precipitation of a metal, or may be
supplied to both sides of the base sheet 11 to form metal foil 50
on both sides of the base sheet 11 by causing precipitation of a
metal and thus to increase the production rate of the metal foil
50.
[0084] As described above, when a base sheet 11 is fed in the
horizontal cell 30, an electrolyte is supplied to one or both sides
of the base sheet 11 through electrolyte supply nozzles 37, and the
electrolyte flows in horizontal flow passages formed between the
base sheet 11 and the anodes 32. Then, metal ions are deposited on
the base sheet 11 by an electro-precipitation reaction caused by
the anodes 32 and the base sheet 11 functioning as cathodes, and
thus an electro-deposition layer is formed on ore or both sides of
the base sheet 11 by the deposited metal ions.
[0085] For this, the electrolyte supply device may include an
electrolyte tank 40 containing an electrolyte and the electrolyte
supply nozzles 37 through which the electrolyte is supplied to a
base sheet 11. The electrolyte contained in the electrolyte tank 40
may be supplied to a base sheet 11 fed into the horizontal cell 30
through the electrolyte supply pipes 35 and the electrolyte supply
nozzles 37. The electrolyte supply nozzles 37 may supply an
electrolyte to one or both sides of a base sheet 11.
[0086] In the accompanying drawings, an electrolyte is supplied to
both sides of a base sheet 11 from the electrolyte tank 40.
However, different electrolytes may be supplied to both sides of a
base sheet 11 to electro-deposit different metals on the both sides
of the base sheet 11 and thus to produce two kinds of metal foil
50.
[0087] An electrolyte may be supplied at high speed through the
electrolyte supply nozzles 37 to horizontal flow passages formed
between a base sheet 11 and the anodes 32. In this case, the
electrolyte may flow in the same direction as the moving direction
of the base sheet 11 or the opposite direction to the moving
direction of the base sheet 11. In addition, the electrolyte may
flow from the electrolyte supply nozzles 37 in the same direction
(forward direction) as the moving direction of the base sheet 11
and the opposite direction (backward direction) to the moving
direction of the base sheet 11.
[0088] If the electrolyte flows in both the forward and backward
directions with respect to the moving direction of the base sheet
11, electro-deposition may occur substantially twice. That is, the
electrolyte supplied in the backward direction may make contact
with the base sheet for a relative short period of time due to a
high velocity relative to that of the base sheet 11 to result in
primary electro-deposition (a relatively small amount of
electro-deposition), and the electrolyte supplied in the forward
direction may make contact with the base sheet 11 for a relatively
long period of time to result in secondary electro-deposition (a
relatively large amount of electro-deposition as compare with that
of the primary electro-deposition).
[0089] In the embodiments of the present disclosure, the
electrolyte supply pipes 35 may include an electrolyte supply pipe
through which an electrolyte is supplied in the same direction
(forward direction) as the moving direction of a base sheet 11 and
an electrolyte supply pipe through which the electrolyte is
supplied in the backward direction. Therefore, since an electrolyte
is supplied through he electrolyte supply pipes 35 in the forward
and backward directions with reference to the moving direction of a
base sheet 11, a non-uniform flow field may be formed by the
electrolyte. The non-uniform flow field may reduce non-uniform
electro-deposition on the base sheet 11, and thus, metal foil 50
having a more uniform thickness may be formed.
[0090] To this end, for example, the electrolyte supply pipes 35
may include inclined electrolyte supply nozzles 37a as shown in
FIG. 5. The inclined electrolyte supply nozzles 37a may be inclined
from the ends of the electrolyte supply pipes 35 in the forward and
backward directions with reference to the moving direction of a
base sheet 11. In another example shown in FIG. 6, the electrolyte
supply pipes 35 may include curved electrolyte supply nozzles 37b.
The curved electrolyte supply nozzles 37b may be curved to the
forward and backward directions with respect to the moving
direction of a base sheet 11 so as to supply an electrolyte between
a base sheet 11 and the anodes 32. In this case, an electrolyte may
be stably supplied to the flow passages formed between a base sheet
11 and the anodes 32 through the curved electrolyte supply nozzles
37b formed on ends of the electrolyte supply pipes 35, and thus the
formation of a non-uniform flow field may be suppressed.
[0091] If the flow field of an electrolyte is stabilized, a vortex
of the electrolyte may not be generated on the base sheet 11, and
thus the electrolyte may make uniform contact with large area of
the base sheet 11. As a result, the rate of electro-precipitation
or electro-deposition may be increased. Therefore, metal foil 50
having a uniform composition, surface, and thickness may be
produced. If an electrolyte is supplied to both sides (upper and
lower sides) of a base sheet 11, the base sheet 11 may be vibrated
due to a pressure difference between upward and downward streams of
the electrolyte, thereby resulting in non-uniform
electro-deposition. However, this problem may be lowered by
horizontally supplying an electrolyte through the curved
electrolyte supply nozzles 37b.
[0092] As described above, the flow field of an electrolyte may be
stabilized by using the curved electrolyte supply nozzles 37b
according to the embodiment of the present disclosure, and this was
experimentally confirmed as explained in examples below.
[0093] In another embodiment of the present disclosure, the
electrolyte supply pipes 35 may include dispensers 38 on ends
thereof. An electrolyte may be supplied from the electrolyte supply
pipes 35 to a base sheet 11 through the dispensers 38 uniformly in
the width direction of the base sheet 11. When an electrolyte is
supplied from the electrolyte supply pipes 35 to flow passages
formed between a base sheet 11 and the anodes 32, the flow rate of
the electrolyte may be varied in directions from the center to the
lateral edges of the base sheet 11, and thus the velocity of the
electrolyte may be varied in the directions. In this case, current
density may be varied in the directions from the center to the
lateral edges of the base sheet 11, and thus an electro-deposition
layer may not be uniformly formed. However, if the dispensers 38
are used, an electrolyte may be uniformly supplied to a base sheet
11 throughout the entire area of the base sheet 11.
[0094] As shown in FIG. 7, the dispensers 38 may be shaped like a
de Laval nozzle. In this case, an electrolyte may be supplied from
the electrolyte supply pipes 35 to a base sheet 11 through the
dispensers 38 uniformly in the width direction of the base sheet 11
without reducing the flow field of the electrolyte.
[0095] As described in the previous embodiments of the present
disclosure, the curved electrolyte supply nozzles 37b may be formed
on ends of the electrolyte supply pipes 35, and the dispensers 38
of the current embodiment may be provided on ends of the curved
electrolyte supply nozzles 37b. Then, an electrolyte may be
uniformly supplied to the entirety of a base sheet 11 while
stabilizing the flow field of the electrolyte, and thus the
velocity of the electrolyte may be kept uniform in the width
direction of the base sheet 11.
[0096] The inclined electrolyte supply nozzles 37a, the curved
electrolyte supply nozzles 37b, the dispensers or combinations
thereof may be formed on the ends of the electrolyte supply pipes
35 to obtain all or some of the effects described in the
embodiments of the present disclosure. Furthermore, non-uniform
electro-deposition caused by an unstable flow field of an
electrolyte supplied in a vertical direction may be reduced, and
thus metal foil 50 having a more uniform thickness may be
produced.
[0097] In addition, the electrolyte supply pipes 35 may include
honey combs 36 therein. Owing to the honey combs disposed in the
electrolyte supply pipes 35, an electrolyte supplied from the
electrolyte supply pipes 35 to a base sheet 11 may form a laminar
flow on the base sheet 11. In this case, the above-described
phenomena in which the flow field of an electrolyte is unstable due
to a vortex may be minimized. Furthermore, although an electrolyte
is supplied at high speed to a base sheet 11, the base sheet 11 may
be less vibrated when the electrical collide with the surface of
the base sheet 11, and thus non-uniform electro-deposition may be
reduced.
[0098] As shown in FIG. 8, the above-described electro-deposition
may be continuously performed two or more times by using a
plurality of (first and second) horizontal cells 30 and 130
arranged linearly. In this case, thicker metal foil 50 may be
produced owing to the plurality of horizontal cells 30 and 130.
That is, the thickness of thicker metal foil 50 may be adjusted to
a desired valve, or although the feeding speed of a base sheet 11
is increased, metal foil 50 having a desired thickness may be
produced with high productivity. For example, the first and second
horizontal cells 30 and 130 may be used as follows. A metal
electro-deposition layer 15 is formed on a base sheet 11 in the
horizontal cell 30. Then, in the second horizontal cell 130, the
same electrolyte as that used in the horizontal cell 30 is supplied
to the base sheet 11 on which the electro-deposition layer 15 is
formed in the first horizontal cell 30 so as to induce additional
electro-deposition and thus to form an electro-deposition layer 15'
on the base sheet 11. In this way, metal foil 50 may be formed.
[0099] Alternatively, in the first and second horizontal cells 30
and 130, different electrolytes may be supplied to a base sheet 11
to form metal foil 50 having a plurality of layers. That is, in
this way, metal foil 50 having various functions may be formed. For
example, in the first horizontal cell 30, a first electrolyte may
be supplied to a base sheet 11 to form a first electro-deposition
layer 15, and in the second horizontal cell 130, a second
electrolyte different from the first electrolyte may be supplied to
form a second electro-deposition layer 15' on the first
electro-deposition layer 15. In this way, metal foil 50 having a
plurality of layers of different metals may be formed by using the
horizontal cells 30 and 130.
[0100] Metal ions of an electrolyte are not limited as long as the
metal ions can be used in an electroforming process. For example,
Cu, Fe, Ni, Zn, Cr, Co, Ag, Pd, Al, Sn, or an alloy thereof may be
included in an electrolyte in the form of metal ions.
[0101] The electrolyte tank 40 may include an electrolyte heater 41
to heat an electrolyte, an electrolyte filter 42 to remove foreign
substances such as slurry from the electrolyte, and an electrolyte
pump 43 to supply the electrolyte to the horizontal cell 30.
[0102] An electrolyte used in electro-deposition may be collected
in the electrolyte tank 40. For this, an electrolyte collecting
pipe 45 may be provided. Since an electrolyte is returned to the
electrolyte tank 40 after being used in electro-deposition, the
concentration of metal ions of the electrolyte stored in the
electrolyte tank 40 may be reduced below a range required for
electro-deposition. Thus, it may be necessary to supplement the
electrolyte with metal ions so as to maintain the metal ion
concentration of the electrolyte at a predetermined level.
[0103] As described above, a base sheet 11 on which an
electro-deposition layer is formed is discharged from the base
sheet supply device 10 through the exit conduct rolls 31'. Then,
the electro-deposition layer formed on the base sheet 11 may be
separated as metal foil 50 by a metal foil stripping device. Since
the metal foil 50 (electro-deposition layer) is coupled to the base
sheet 11 having oxide films by a surface tension between the metal
foil 50 and the base sheet 11, the metal foil 50 may be separated
from the base sheet 11 by applying a shearing force. That is, the
metal foil stripping device may apply a shearing force (shearing
stress) to the metal foil 50 to separate the metal foil 50 from the
base sheet 11. For example, the metal foil stripping device may
include a plurality of stripping rollers 51 capable of applying
shearing forces. In addition, metal foil 50 may be separated from
one or both sides of a base sheet 11 simultaneously or one after
another by causing a velocity difference between the metal foil 50
and the base sheet 11.
[0104] After the metal foil 50 is separated from the base sheet 11,
the metal foil 50 and the base sheet 11 may be wound by using
coiling devices 55 and 72, respectively. For example, the coiling
devices 55 and 72 may be cylindrical coiling devices. After proper
amounts of the metal foil 50 and the base sheet 11 are coiled
around the coiling devices 55 and 72, the metal foil 50 and the
base sheet 11 may be cut and wound around other coiling devices 55
and 72. For example, a metal foil cutting device 54 and a base
sheet cutting device 71 may be used. A base sheet 11 may be cut at
a bonding line thereof.
[0105] According to an embodiment of the present disclosure, the
horizontal electroforming apparatus 100 may include a post
processing device to process metal foil 50 after the metal foil 50
is discharged from the horizontal cell 30. In this case, the metal
foil 50 may be process after or before the metal foil 50 is
separated from a base sheet 11. The post processing device may
include post-cleaning devices 52, drying devices (not shown), and
heat-treatment devices 53.
[0106] Since an electrolyte may remain on metal foil 50
electro-deposited on a base sheet 11, the metal foil 50 may be
cleaned. For example, the post-cleaning devices 52 may remove an
electrolyte and other foreign substrates remaining on metal foil 50
by using an acid solution and water. In addition, a soft brush may
be used to effectively remove a remaining electrolyte. Such a
cleaning process may be performed on an electro-deposition layer
(metal foil 50) formed on a base sheet 11, or may be performed on
the metal foil 50 after the metal foil 50 is separated from the
base sheet 11.
[0107] After cleaning, air may be blown to the metal foil 50 at a
high pressure so as to remove moisture from the metal foil 50. In
addition, a high-temperature gas blower or a heater may be used to
dry the metal foil 50.
[0108] The metal foil 50 formed by electroforming has a
nanostructure, and a heat treatment process may be performed on the
metal foil 50 to improve the nanostructure of the metal foil 50.
Metal foil 50 formed by electroforming may be processed at
different temperatures according to the use of the metal foil 50.
For example, at 300.degree. C. to 600.degree. C., the structure of
metal foil 50 such as Fe foil may be changed from a nanostructure
to a microstructure due to growth of abnormal grains. Such a change
caused by growth of abnormal grains may result in errors when
products are produced using the metal foil 50. For example, if
electric circuits are formed on the metal foil 50, the electric
circuits may be stripped or short-circuited in the following
high-temperature process.
[0109] Therefore, if metal foil 50 is formed in a temperature range
of abnormal grain growth, the metal foil may be previously
heat-treated to change the microstructure of the metal foil 50 so
as to prevent the structure of the metal foil 50 from changing in
the next processes. To this end, the heat-treatment devices 53 may
be used. Process conditions of such a heat treatment process are
not limited but may be varied according to a desired structure of
metal foil 50. For example, such a heat treatment process may be
performed at 300.degree. C. to 600.degree. C. In addition, such a
heat treatment process may be performed under an inert gas
atmosphere such as a nitrogen or argon atmosphere to prevent
surface oxidation, and methods such as induction heating, direct
heating, and contact heating may be used.
[0110] While the method for manufacturing metal foil 50 by
electroforming and the horizontal electroforming apparatus 100 have
been described according to the embodiments of the present
disclosure, it will be apparent to those skilled in the related art
that modifications and variations could be made without departing
from the spirit and scope of the present disclosure.
Mode for Invention
[0111] Hereinafter, some embodiments of the present disclosure will
be described more specifically according to the following examples.
However, the scope and spirit of the present disclosure are not
limited to the examples.
Example 1
[0112] simulation was performed. In the simulation, an electrolyte
was supplied between a base sheet and anodes in the above-described
apparatus while using horizontal anodes having a uniform thickness
in the width direction thereof as the anodes and curved anodes (not
divided into sub electrodes) such as shown in FIG. 3 as the
anodes.
[0113] The width of the base sheet was set to be 1000 nm, and the
velocity of the electrolyte was set to be 1000 in Reynolds number
to cause a laminar flow.
[0114] After the simulation, current density distribution along the
width of the base sheet was measured as shown in FIG. 9. In FIG. 9,
positions along a half of the base sheet from an electrolyte supply
pipe are denoted.
[0115] As shown in FIG. 9, in the case of using the horizontal
anodes, current density started to noticeably increase after about
the 300-mm position in a center-to-edge direction. However, in the
case of using the curved anodes, current density was almost
constant along the base sheet and started to gradually increase
after about the 400-mm position.
[0116] Furthermore, in the case of using the curved anodes, the
current density measured at the 500-mm position was lower than the
current density measured at the 500-mm position in the case of
using the horizontal anodes by about 35%, and a region having a
uniform current density distribution was increased.
[0117] Eased on the results, it may be understood that the
distribution of current density can be more uniformly maintained by
varying the shapes of anodes to vary the distance between a cathode
and the anodes, as compared with the case of using horizontal,
anodes.
Example 2
[0118] Another simulation was performed for the cases in which an
electrolyte supply nozzle such as shown in FIG. 10A, and curved
injection nozzles such as shown in FIGS. 105 and 10C were used
together with electrolyte supply pipes to supply an electrode
through the nozzles, respectively. In each case, the electrolyte
was supplied in a laminar flow condition and a turbulent flow
condition, respectively, so as to evaluate the degree of
stabilization of flow fields of the electrolyte.
[0119] Stream lines of the flow fields of the electrolyte in the
simulation are shown in FIGS. 11A to 12C, FIGS. 11A to 11C show
streamlines when the electrolyte was supplied in a laminar flow
condition (Reynolds number Re=1000), and FIGS. 12A to 12C show
streamlines when the electrolyte was supplied in a turbulent flow
condition (Reynolds number Re=5000).
[0120] When the electrolyte was supplied to a laminar flow field as
shown in FIG. 11A through the electrolyte supply nozzle as shown in
FIG. 10A, the flow field was stabilized after the electrolyte
flowed about 0.15 m. However, when the electrolyte was supplied to
a laminar flow field as shown in FIG. 115 through the curved
electrolyte supply nozzle as shown in FIG. 105, the flow field was
stabilized after the electrolyte flowed about 0.03 m, and when the
electrolyte was supplied to a laminar flow field as shown in FIG.
11C through the curved electrolyte supply nozzle as shown in FIG.
100, the flow field was also stabilized after the electrolyte
flowed about 0.03
[0121] From the above-described results, it may be understood that
when an electrolyte is supplied to a laminar flow field as shown in
FIGS. 11A to 11C, the flow field may be stabilized more rapidly in
the case of using a curved electrolyte supply nozzle as shown in
FIGS. 10B and 10C than in the case of using an electrolyte supply
nozzle as shown in FIG. 10A. In addition, a uniform
electro-deposition region may also be increased in the former
case.
[0122] When the electrolyte was supplied to a turbulent flow field
as shown in FIG. 12A through the electrolyte supply nozzle as shown
in FIG. 10B, the flow field was stabilized after the electrolyte
flowed about 0.15 m. However, when the electrolyte was supplied to
a turbulent flow field as shown in FIG. 12B through the curved
electrolyte supply nozzle as shown in FIG. 10B, the flow field was
stabilized after the electrolyte flowed about 0.05 m, and when the
electrolyte was supplied to a turbulent flow field as shown in FIG.
12C through the curved electrolyte supply nozzle as shown in FIG.
100, the laminar flow field was also stabilized after the
electrolyte flowed about 0.03 m.
[0123] From the above-described results, it may be understood that
when an electrolyte supplied to a turbulent flow field, the flow
field may be stabilized more rapidly in the case of using a curved
electrolyte supply nozzle like in the embodiments of the present
disclosure than in the case of using a right-angled electrolyte
supply pipe. In addition, a uniform electro-deposition region may
also be increased in the former case.
* * * * *