JP2002294481A - Electrolysis apparatus for manufacturing metal foil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolysis apparatus for manufacturing a metal foil, which precisely controls a thickness of a metal foil in a transverse direction to be uniform, when continually manufacturing the metal foil with electrolytic deposition using a drum-shaped rotating cathode. SOLUTION: The electrolysis apparatus for manufacturing a metal foil has a drum-shaped rotating cathode on which metal electrodeposits to form the foil, an anode which is arranged so as to face circumference of the rotating cathode, and a liquid feeding means having a supply port for supplying an electrolytic solution from a lower part of the rotating cathode, between the rotating cathode and the anode, electrodeposits metal on the periphery of the rotating cathode thorough an electrolytic reaction, while supplying the electrolytic solution from the liquid feeding means, and continuously peels the electrodeposited metal foil away from the rotating cathode. The liquid feeding means has a tabular damper body over the whole length of the rotation cathode, above the electrolytic solution supply port.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal foil electrolytic manufacturing apparatus, and more particularly, to a manufacturing technique for uniforming the thickness of a metal foil in a foil width direction.

[0002]

2. Description of the Related Art In recent years, metal foils have been used in various applications, such as electrolytic copper foils as printed wiring board materials.
It is manufactured in large quantities. As a method for producing such a metal foil, a method utilizing an electrolytic reaction is known.

As an apparatus for electrolytically producing metal foil utilizing this electrolytic reaction, for example, an apparatus for continuously producing metal foil using a drum-shaped rotating cathode shown in FIG. 4 is used. A metal foil electrolytic production apparatus 1 shown in FIG. 4 includes a drum-shaped rotating cathode 2 for electrodepositing a metal foil, an anode 3 disposed to face the peripheral surface of the rotating cathode 2, a rotating cathode 2 and an anode. A liquid supply means 5 having an electrolytic solution supply port 4 for supplying an electrolytic solution from below the rotating cathode 2 between the rotating cathode 2 and the rotating cathode 2 by an electrolytic reaction while supplying the electrolytic solution from the liquid supplying means 5. A metal is electrodeposited on the peripheral surface, and the electrodeposited metal foil 6 is continuously peeled off from the rotating cathode 2.

[0004] The metal foil obtained by such an electrolytic manufacturing apparatus has many characteristic requirements such as strength, surface properties, thickness uniformity, etc., which can be used for various applications, and it is necessary to produce a metal foil satisfying these requirements. In particular, in a copper foil used as a material for a printed wiring board, uniformity of the foil thickness as well as the strength characteristics and surface properties are very important as the quality of the metal foil.

[0005] In many cases, the metal foil obtained by the metal foil electrolytic manufacturing apparatus is manufactured by continuously stripping the metal deposited on the rotating cathode to make a long metal foil into a roll. In such a case, the thickness of the metal foil in the longitudinal direction can be relatively easily and uniformly controlled by controlling the rotation speed of the rotating cathode, but it is not possible to uniformly control the thickness in the width direction of the metal foil. It's not easy.

Conventionally, in order to improve the thickness uniformity in the width direction of a metal foil obtained by this metal foil electrolytic manufacturing apparatus, the anode facing the rotating cathode is divided in the width direction to supply the electrolytic current in the width direction. There is proposed a countermeasure to control by.

[Problems to be solved by the invention]

However, such an improvement in the current supply method can control the uniformity of the thickness of the metal foil in the width direction to some extent, but is not sufficiently satisfactory. Further, in order to supply different electrolytic currents to the divided anodes, the structure of the metal foil electrolytic manufacturing apparatus becomes complicated, which is not preferable in terms of apparatus design.

Further, quality requirements for metal foils in recent years are as follows:
It is getting stricter with the technical progress of each application.
There is a tendency to strongly demand a metal foil having a small foil thickness. For example, in the case of electrolytic copper foil used as a material for a printed wiring board, a foil thickness of 35 μm or 18 μm has conventionally been the mainstream, but recently, a demand for an ultra-thin copper foil of 12 μm or 9 μm has been increasing. When such an ultra-thin copper foil is manufactured by the above-mentioned metal foil electrolytic manufacturing apparatus, if the thickness uniformity in the width direction is not precisely maintained, when the metal foil is peeled off from the rotating cathode and wound up, the foil is wrinkled. And it becomes difficult to use it as a product. It is difficult to precisely control the uniformity of the thickness in the width direction required for manufacturing such an ultrathin metal foil in the conventional measures for achieving the uniformity of the thickness in the width direction of the metal foil. . Therefore, in order to stably supply thin metal foil such as ultra-thin copper foil to the market, it is essential to establish a metal foil electrolytic manufacturing technology that can make the width direction thickness more uniform than before. It can be said that.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and when a metal foil is continuously manufactured by electrodeposition using a drum-shaped rotating cathode, the foil thickness in the width direction of the metal foil is reduced. It is an object of the present invention to provide a metal foil electrolytic manufacturing apparatus capable of precisely and uniformly controlling the production.

[0010]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have studied in detail a metal foil electrolytic production apparatus using a drum-shaped rotating cathode, and found that a metal foil electrolytic manufacturing apparatus is provided between the rotating cathode and the anode. The present invention was conceived, focusing on the fact that the liquid flow state of the electrolytic solution supplied to the metal foil greatly affects the uniformity of the thickness of the metal foil in the width direction.

The present invention provides a rotating cathode in the form of a drum on which a metal foil is electrodeposited, an anode opposed to the rotating cathode along the peripheral shape thereof, and a rotating cathode disposed between the rotating cathode and a lower side of the rotating cathode. A liquid supply means having an electrolytic solution supply port for supplying an electrolytic solution, wherein a metal is electrodeposited on a rotating cathode peripheral surface by an electrolytic reaction while supplying the electrolytic solution from the liquid supplying means, and the electrodeposited metal foil is placed on the rotating cathode. In the metal foil electrolytic production apparatus which is continuously peeled off from the electrode, the liquid supply means has a plate-shaped damper body extending in the width direction of the rotating cathode above the electrolyte supply port.

When an electrolytic solution is supplied from below the rotating cathode between a rotating cathode in the form of a drum on which a metal foil is electrodeposited and an anode arranged along the peripheral surface of the rotating cathode, FIG. As indicated by the dashed arrow, the supplied electrolyte collides with the surface of the rotating cathode at a position facing the electrolyte supply port, and separates the liquid flow rising in two directions along the peripheral surface shape of the rotating cathode. Form.

In the vicinity of the surface of the rotating cathode opposite to the electrolyte supply port, the electrolyte collides with the surface of the rotating cathode, so that a vortex state is easily generated, and the liquid flowing state rises along the peripheral surface of the rotating cathode. In comparison, the liquid flow becomes very complicated. Further, on the surface of the rotating cathode opposite to the electrolyte supply port, new electrolyte is continuously supplied, so that metal ions to be subjected to electrodeposition are always sufficiently supplied. . In consideration of this, the flow of the electrolyte is complicated on the surface of the rotating cathode facing the electrolyte supply port, so that the supply amount of the electrolyte when viewed in the width direction is smaller than that on the other rotating cathode surfaces. It is considered that it is easy to be uniform. Then, on the rotating cathode surface where the electrolyte collides, metal ions to be used for electrodeposition are always sufficiently supplied,
The present inventors have presumed that electrodeposition causing unevenness of the thickness of the metal foil in the width direction has occurred.

In order to eliminate the complicated liquid flowing state generated on the surface of the rotating cathode at a position facing the electrolyte supply port, the present inventors set a plate extending in the width direction of the rotating cathode above the electrolyte supply port. A damper body was provided. By providing this plate-shaped damper body, as a result of eliminating a complicated liquid flow state generated near the surface of the rotating cathode at a position facing the electrolyte supply port, the uniformity of the thickness in the width direction is reduced as estimated by the present inventors. They found that it could be greatly improved. And by installing this plate-shaped damper body,
It has also been found that there is an effect of reducing abnormal precipitation that occurs on the metal foil surface.

[0015] The plate-like damper body of the metal foil electrolytic manufacturing apparatus according to the present invention has a liquid flow such that the electrolyte supplied from the electrolyte supply port toward the rotating cathode surface directly collides with the rotating cathode surface. It is only necessary that the state can be eliminated, and there is no restriction on the shape, arrangement, and the like. In short, a state in which the plate-shaped damper body provided across the width of the rotating cathode between the electrolytic supply port and the rotating cathode surface obstructs the flow direction of the electrolyte supplied from the electrolyte supply port toward the rotating cathode surface. Any shape and arrangement may be used as long as

It is desirable that the plate-shaped damper body of the metal foil electrolytic manufacturing apparatus according to the present invention be provided with a flow dividing protrusion extending in the plate longitudinal direction at the plate width center. When the plate-shaped damper body is provided above the electrolyte supply port, the supplied electrolyte directly collides with the plate-shaped damper body, and a complicated liquid flow such as a vortex flow is easily formed at that portion. Therefore, if a diverting protrusion is provided in the longitudinal direction of the plate at the center of the plate width of the plate-shaped damper body, the electrolyte that directly collides with the plate-shaped damper body is divided into two directions by the diverting protrusion. It will rise smoothly along the rotating cathode peripheral surface shape. By providing the flow dividing projections on the plate-shaped damper body, the thickness uniformity of the metal foil in the width direction can be more reliably improved.

In the metal foil electrolytic manufacturing apparatus according to the present invention, the electrolytic solution supply port is divided into a plurality in the width direction of the rotating cathode, and the flow rate of the electrolytic solution supplied from the divided electrolytic solution supply port can be adjusted. It is preferred that This makes it easier to more precisely control the uniformity of the thickness of the metal foil in the width direction. The metal foil electrolytic manufacturing apparatus according to the present invention often uses a relatively large rotating cathode or anode in order to achieve high production efficiency. It is difficult to uniformly form the materials of the rotating cathode and the anode that constitute the rotating cathode and the anode. Therefore, the thickness variation in the width direction of the manufactured metal foil also tends to be different for each device. Even in such a case where the electrodeposition is biased for each device, the flow rate of the electrolytic solution supplied from the divided electrolytic solution supply ports is adjusted according to the thickness variation in the foil width direction in each device. Then, the uniformity of the thickness in the metal foil width direction can be easily controlled precisely in synergy with the effect of the plate-shaped damper body according to the present invention.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

The apparatus for electrolytically manufacturing a metal foil according to this embodiment has a structure basically similar to that of a conventionally used apparatus, and FIG. 4 shows a schematic sectional view thereof. Metal foil electrolytic production equipment 1
Is provided with a drum-shaped rotating cathode 2 on which a metal foil is electrodeposited, and an anode 3 opposed to the rotating cathode 2 along the peripheral surface shape of the rotating cathode 2. The rotating cathode 2 and the anode 3 are connected to a power supply device (not shown). And, about half of the volume of the rotating cathode 2 is immersed in the electrolytic solution. Anode 3
Is divided into two, and between the divided anodes 3 is provided an electrolytic solution supply means 5 having an electrolytic solution supply port 4 for supplying an electrolytic solution from below the rotating cathode 2.
When the electrolytic solution is supplied from the electrolytic solution supply port 4 toward the rotating cathode 2, the electrolytic solution flows so as to rise along the peripheral surface shape of the rotating cathode 2, as shown by the broken line in FIG. Overflow. The metal foil 6 deposited on the peripheral surface of the rotating cathode 2 is peeled off from the rotating cathode 2 and wound up on a winding roll 9 via a guide roll 8.

FIG. 1 is an enlarged perspective view of a portion surrounded by A in FIG. The electrolyte supply port 4 of the electrolyte supply means 5 is divided into a plurality in the width direction of the rotating cathode 2,
Each of the divided electrolytic solution supply ports 4 ′, 4 ′,... Is provided with flow rate adjusting means for adjusting the flow rate of the supplied electrolytic solution, although not shown.

FIG. 2 is an enlarged cross-sectional view of the metal foil electrolytic manufacturing apparatus 1 according to the present embodiment, in which a plate-shaped damper is disposed above the electrolyte supply port 4. FIG. 3 is a partially enlarged perspective view of the plate-shaped damper body. The plate-shaped damper body 10 has a length substantially equal to the width of the rotating cathode 2 and has a plate width slightly longer than the width of the electrolyte supply port 4. Are formed over the longitudinal direction of the plate. In addition, a partition wall 12 is provided on the lower surface side of the plate-shaped damper body 10, that is, on the side facing the electrolyte supply port 4 in accordance with the divided electrolyte supply port 4 '. The partition wall 12 is erected on a fixed plate 13 located on both sides of the electrolyte supply port 4. Therefore, a liquid outlet 14 is formed in the lower part of the plate-shaped damper body 10 in accordance with the divided electrolytic solution supply ports 4 ', 4',....

The plate-like damper 1 shown in FIGS. 2 and 3
When 0 is disposed above the electrolyte supply port 4, the electrolyte supplied from the electrolyte supply port 4 as shown by the arrow in FIG.
Collision with the plate-shaped damper body 10 and formation of a liquid flowing state in which the flow direction is changed by the branching projection 11 to be divided into two directions and ascending along the peripheral surface shape of the rotating cathode 2. become.

Next, a description will be given of the results obtained by producing a copper foil as a metal foil using the metal foil electrolytic production apparatus according to the present embodiment, and examining the thickness distribution and surface properties of the produced copper foil in the foil width direction.

In the case of producing a copper foil as a metal foil, a drum-shaped rotating cathode whose peripheral surface is made of Ti (diameter 3 m, width 1.35)
m) and an insoluble anode called DSA, and a copper foil electrolytic production apparatus arranged so that a gap between the rotating cathode and the insoluble anode was about 20 mm. Then, the plate-shaped damper body provided with the branching projection is formed of a Ti material (the partition plate and the fixing plate are also formed of the Ti material), and at an intermediate position between the rotating cathode and the anode, the electrolyte supply port is provided. Arranged above. The plate-shaped damper was installed with an insulating material interposed between the anode and the fixed plate so that no electrolytic current flowed through the plate-shaped damper. Further, a copper sulfate solution was used as an electrolytic solution.

In this copper foil electrolytic manufacturing apparatus, a copper foil is manufactured by performing an electrolytic treatment in each of the case where the plate-shaped damper body is arranged and the case where the plate-shaped damper body is not arranged, and the thickness distribution and surface texture in the copper foil width direction are produced. Was compared.

First, the result of measuring the thickness distribution in the copper foil width direction will be described. The measurement of the thickness distribution in the width direction was performed using a copper foil subjected to electrolytic treatment by supplying an electrolytic solution while the rotating cathode was stationary. The sample for which the thickness distribution in the width direction was measured was subjected to electrolytic treatment so as to form a copper foil equivalent to a thickness of 70 μm, and after the electrolytic treatment was stopped, the copper foil deposited on the half circumferential surface of the rotating cathode was peeled off. Was used. From the sample obtained by this static electrolysis, a length of 150 mm × a width of 1350 mm was obtained in the circumferential direction of the rotating cathode circumferential surface.
(Rotating cathode width) A total of four strips were cut out, two at the front and two at the part facing the electrolyte supply port (A).
~ D).

Each of the cut-out strip-shaped samples was further subdivided into strips having a width of 10 mm and a length of 100 mm. By this subdivision, the strip sample was divided into 84 strips in the width direction. Then, the mass thickness (g / m ² ) was calculated by measuring each mass of the strip, and this value was defined as the thickness of the copper foil.

Four strip samples (A) cut out from the static electrolysis
-D), the mass of each of the 84 divided strips was measured,
FIGS. 5 and 6 show plots corresponding to the position in the width direction.

FIG. 5 shows a case where a plate-shaped damper is arranged, and FIG. 6 shows a case where no plate-shaped damper is arranged. In these band-shaped samples A to D, a portion between the band-shaped samples B and C is a position corresponding to a portion facing the electrolyte supply port. In FIGS. 5 and 6, the maximum mass thickness value of the strip divided into 84 pieces from the strip sample is specified, the difference between the mass thickness value of each strip and the maximum mass thickness value is calculated, and each mass thickness difference is calculated. By dividing by the maximum mass thickness value, each thickness ratio (%) value is calculated, and the values are plotted.

When no plate-shaped damper is provided, A
In all of the band-shaped samples Nos. To D, there was a difference in mass thickness of 14.2% at the maximum, and there was a difference in mass thickness of 6.5% on average. As can be seen from FIG. 6, when the plate-shaped damper bodies are not arranged, the mass in the width direction of each of the band-shaped samples A to D varies considerably, and the standard deviation at this time is 3. 05 (value calculated from all data of A to D).

On the other hand, when the plate-shaped damper body was disposed, the difference in the mass thickness was reduced to 10.8% at the maximum, and the difference in the mass thickness was 3.4% on average. Then, as shown in FIG. 5, when the plate-shaped damper body is arranged,
It was confirmed that the mass in the width direction of each of the strip samples A to D was very uniform, and the standard deviation was 1.89 (a value calculated from all data from A to D).
In the present embodiment, the thickness distribution in the width direction was measured to be 10 m width.
It is performed from a strip divided into mx 100 mm long strips, but when divided at such a precise level in the copper foil width direction, it was possible to control the dispersion to a low standard deviation of 1.89. This is something that could not be achieved at all with a conventional copper foil manufacturing apparatus.

Next, the results of an investigation of the surface properties of the copper foil will be described. The comparative examination of the surface properties is 35 μm thick
Was manufactured by observing abnormal precipitation on the rough surface (mat surface; surface corresponding to the electrodeposition finished surface) of the obtained copper foil. The abnormal deposition refers to a portion on the surface of the metal foil to be manufactured, on which the electrodeposition is completed, which is deposited in a state of being abnormally protruded from the periphery.
Investigation of this surface property was carried out by measuring 100 mm x
A sample of 100 mm square was randomly sampled, and the rough surface side of the sample was observed with a stereoscopic microscope to confirm the presence or absence of abnormal precipitation.

As a result, in the copper foil without the plate-shaped damper body, almost all of the samples were found to have abnormal precipitation. On the other hand, in the case of the copper foil provided with the plate-shaped damper body, in any of the samples, the number of abnormal precipitations was very small, and it was confirmed that the plate-shaped damper body was effective in reducing abnormal precipitation. .

[0034]

According to the present invention, it is possible to precisely control the uniformity of the thickness of a metal foil in the width direction when the metal foil is continuously produced by electrodeposition using a drum-shaped rotating cathode. It is also possible to suppress the occurrence of abnormal precipitation occurring on the surface of the metal foil.

[Brief description of the drawings]

FIG. 1 is a partially enlarged perspective view of a metal foil electrolytic manufacturing apparatus.

FIG. 2 is a partially enlarged cross-sectional view of a metal foil electrolytic manufacturing apparatus in which a plate-shaped damper body is arranged.

FIG. 3 is a partially enlarged perspective view of a plate-shaped damper body.

FIG. 4 is a schematic sectional view of a metal foil electrolytic manufacturing apparatus.

FIG. 5 is a width-direction thickness distribution graph when a plate-shaped damper body is arranged.

FIG. 6 is a width-direction thickness distribution graph when a plate-shaped damper body is not arranged.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal foil electrolytic manufacturing apparatus 2 Rotating cathode 3 Anode 4, 4 'Electrolyte supply port 5 Liquid supply means 6 Metal foil 7 Electrolysis tank 8 Guide roll 9 Winding roll 10 Plate damper body 11 Dividing projection 12 Partition wall 13 Fixed Plate 14 Liquid outlet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoru Fujita 652-2 Kamakurabashi, Ageo-shi, Saitama Pref. 656-2Mitsui Metal Mining Co., Ltd.

Claims (3)

[Claims] 1. A rotating cathode in the form of a drum on which a metal foil is electrodeposited, an anode disposed to face the peripheral surface of the rotating cathode, and an electrolytic solution between the rotating cathode and the anode from below the rotating cathode. A liquid supply means having an electrolyte supply port for supplying a metal, electrodeposition of a metal on the peripheral surface of the rotating cathode by an electrolytic reaction while supplying an electrolytic solution from the liquid supplying means, and continuous deposition of the electrodeposited metal foil from the rotating cathode. A metal foil electrolytic manufacturing apparatus, wherein the liquid supply means includes a plate-like damper body extending in a width direction of the rotating cathode, above the electrolyte supply port. 2. The plate-shaped damper body is provided with a diverting projection extending in the plate longitudinal direction at the plate width center.
4. The metal foil electrolytic production apparatus according to claim 1. 3. The electrolytic solution supply port is divided into a plurality of portions in the width direction of the rotating cathode, and the flow rate of the electrolytic solution supplied from the divided electrolytic solution supply port can be adjusted. The metal foil electrolytic manufacturing apparatus according to the above.