JPH0436491A - Device for producing electrolytic copper foil - Google Patents

Abstract

PURPOSE:To obtain the high-quality electrolytic copper foil uniform in thickness in the cross and longitudinal directions, by forming a part of an electrode as the plural split foil thickness uniformizing anodes and separately controlling the quantity of electricity to be supplied to each anode. CONSTITUTION:A cathode drum 1 as a rotary cylinder is partially dipped in an electrolyte and confronted with at least one circular insoluble anode 3. The anode 3 on the copper foil discharge side is formed as a foil thickness uniformizing anode 4. An electrolyte is supplied from a gap between the anodes 3 and 4 and flows through the gap between the cathode drum 1 and the anodes 3 and 4. Under these conditions, a specified voltage is maintained between the cathode drum 1 and the anode 3 by a rectifier 5. As the cathode drum 1 rotates, copper is deposited from the electrolyte, and the crude foil in specified thickness is released by an appropriate releasing means. Furthermore, a slave rectifier 7 is connected between the discrete split anodes 4 and the cathode drum 1 to separately control the quantity of electricity to be supplied to each anode, and the thickness of the electrolytic copper foil produced is uniformized.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an apparatus for manufacturing electrolytic copper foil, and in particular, a dividing device for making the thickness of the electrolytic copper foil uniform so that the thickness of the electrolytic copper foil produced is uniform. The present invention relates to an apparatus for manufacturing electrolytic copper foil, characterized in that it is provided with anodes and means for individually controlling the amount of electricity supplied to the divided anodes for making the foil thickness uniform. According to the present invention, a high quality electrolytic copper foil having a uniform thickness in the width direction and the length direction can be obtained.

(Prior art) Electrolytic copper foil is produced by flowing an electrolytic solution between an anode made of an insoluble metal and a cathode drum made of a metal whose surface is polished to a mirror finish, and then creating an electric potential between the anode and the cathode drum. It is produced by electrodepositing copper on the surface of the cathode shell, and peeling off the electrodeposited material from the cathode shell once it has reached a predetermined thickness. The resulting copper foil is called the main tube, and is then subjected to various surface treatments and made into products.

In an electrolytic copper foil production facility, after the anode has been operated for a certain period of time, the distance between the anode and the cathode becomes uneven, especially due to wear and tear, and the equipment becomes unusable. In particular, variations in thickness occur in the width direction. FIG. 4 is an explanatory diagram showing the arrangement relationship between a cathode body and an anode in conventional electrolytic copper foil production.

In an electrolytic cell (not shown) that stores an electrolytic solution, the cathode body 1 is designed to be able to rotate while being partially immersed in the electrolytic solution. (clockwise here).

For example, two anodes 3 are disposed to cover approximately the immersed lower half of the cathode barrel 1 and at a constant distance from the surface of the rotating barrel. In the electrolytic cell, electrolyte is supplied from the 6 o'clock position (the position of the hour hand, the same applies hereinafter) between the two anodes 3, and the electrolyte flows through the gap between the cathode body and the anode and from the upper edge of the anode. It gets wet and gets circulated. A rectifier 5 maintains a predetermined voltage between the cathode shell and the anode.

As the cathode body 1 rotates, the thickness of the copper electrodeposited from the electrolytic solution increases, and at approximately the 12 o'clock position, the main strip having a predetermined thickness is peeled off by an appropriate peeling means and wound up.

The anode is locally depleted during use. As a result, the distance between the cathode body and the anode varies, and the thickness of the main bars produced varies in the width direction, as shown in FIG.

One of the important quality requirements for electrolytic copper foil is uniformity of thickness in the width direction.

In order to achieve uniformity in the thickness of electrolytic copper foil in the width direction, conventional measures have been widely taken.

(1) Anode milling: In electrolytic copper foil production equipment, after a certain period of operation, the anode becomes unusable due to wear and tear and unevenness occurs between the anode and cathode.

A state that cannot be used refers to a state in which the electrolytic voltage has increased abnormally or a state in which the thickness of the manufactured copper foil has large variations. To avoid this situation, the surface of anodes that have been used for a certain period of time is machined into a cylinder using a special cutting machine.

(2) Partially scraping the anode After near-node milling, the thickness variation in the width direction of the copper foil manufactured is measured, and according to the data, the surface of the anode is partially scraped to correct the thickness of the copper foil.

(Problems to be Solved by the Invention) The above two conventional countermeasures are the inability to make corrections during operation, the variation in thickness in the width direction due to uncertain causes other than the anode, and the variation in thickness due to the cathode body, for example. , it has disadvantages such as not being able to deal with variations in thickness due to changes in the flow of the electrolyte or unevenness, shaving the anode part is a time-consuming and troublesome process, and it is not always easy to achieve the desired effect. .

The object of the present invention is to develop a new electrolytic copper foil manufacturing apparatus that enables thickness correction during operation, especially thickness correction in the width direction, and also enables thickness correction due to uncertain causes other than the anode. be.

(Means for Solving the Problems) The present inventors configured a small number of anodes (some of which are divided in the width direction as a plurality of foil thickness equalizing anodes,
We came up with the idea of individually controlling the divided anodes for thickness uniformity so that the thickness of the electrolytic copper foil in the width direction is uniform. The amount of electricity supplied to the divided auxiliary anodes for equalizing the foil thickness is individually controlled.

Based on this knowledge, the present invention provides a rotatable cathode shell,
at least one anode facing the cathode body,
In an electrolytic copper foil production apparatus that flows an electrolytic solution between the cathode body and the anode, electrodeposit copper on the surface of the cathode body, and peel the electrodeposited copper foil from the cathode body, a part of the anode An electrolytic copper foil comprising a plurality of foil thickness equalizing anodes divided in the width direction, and comprising means for individually controlling the amount of electricity supplied to the foil thickness equalizing divided anodes. We provide manufacturing equipment for

(Explanation of Embodiments) According to the present invention, a portion of the anode already explained in FIG. It is configured as a divided anode for making the thickness uniform.Of course, the divided anode can also be installed as an auxiliary anode in addition to the existing anode.

FIGS. 1 and 2 show an example in which the upper end of the copper foil side of the two anodes is configured as a divided anode for uniformizing the foil thickness.

FIG. 3 shows an example in which not only the upper end of the anode on the copper foil draw-out side but also the electrodeposition start side is configured as a divided anode for making the foil thickness uniform. Control is performed both at the start of electrodeposition and at the end of electrodeposition.

The larger the number of divisions, the more finely controlled the control, but the more difficult it is to manufacture and maintain, and the number of divisions varies from 10 to 40 pieces, usually 20 to 30 pieces, depending on the width of the copper foil to be manufactured and the status of the electrolytic copper foil manufacturing equipment. It is divided into front and back.

To explain the operation mode of producing electrolytic copper foil using the apparatus of the present invention, an electrolytic tank (
(not shown), a rotating cylindrical cathode layer 1, for example made of stainless steel or titanium, is partially immersed in an electrolyte and is here mounted by means of a support device so as to rotate clockwise. For example, two arcuate insoluble anodes 3 are disposed to cover approximately the immersed lower half of the cathode layer 1 and at a constant distance from the surface of the cathode body.

The anode is also supported in the electrolyte by a suitable device,
Some positional adjustment with respect to the cathode layer is possible. The anode is
It is made from lead, a lead alloy of lead and antimony, silver, indium, etc. Alternatively, the anode is a DSE or D S
A (Dimension 5tableElect
It has a structure in which a valve metal represented by titanium is coated with a platinum group metal or an oxide thereof. The anode preferably consists of two anode sheets disposed along approximately the lower 174 portion of the cathode layer as shown, but in some cases there may be one, three, or even four anode sheets. It can also be constructed from an anode sheet of

According to the present invention, preferably at least a portion of one of the anodes on the copper foil extraction side is configured as the divided anode 4 for equalizing the foil thickness as described above. An appropriate number of divided anodes 4°, 4'', 4'''', . . . are formed.

The spacing between the cathode layer and the anode is generally maintained at a constant position in the range of 2 to 100 mm. The narrower the spacing, the less electricity is required, but it becomes more difficult to control film thickness and quality.

The spacing between the cathode layer and the anode forms a flow path for the electrolyte. Electrolyte is supplied from the 6 o'clock position between anodes 3 and 4 through a suitable pump (not shown) in the bath, and the electrolyte flows to both sides through the gap between the cathode layer and the anode to the upper edge of each anode. It leaks out and is circulated.

A rectifier 5 maintains a predetermined voltage between the cathode layer and the anode.

As the cathode layer 1 rotates, the electrodeposition of copper from the electrolyte is
It starts at the 3 o'clock position and gradually increases in thickness until it reaches the 9 o'clock position.
At the 12 o'clock position, the electrodeposition is completed to a predetermined thickness, and at approximately the 12 o'clock position, the main strip, which has a predetermined thickness, is peeled off by an appropriate peeling means and wound up. The anode is
In particular, lead-based anodes are locally worn out during use. Therefore,
The spacing between the cathode layer and the anode varies. In addition, variations in thickness may occur due to the cathode layer, and certain deflections or uneven flow of the electrolyte may occur. Together, these tend to cause local variations in the thickness of the main reinforcement as shown in FIG.

According to the present invention, when the thickness of the main reinforcing bars in the width direction is detected after peeling and the variation in thickness exceeds an allowable value, the variation in power supplied to a specific divided anode 4 corresponding to a specific portion in the width direction is eliminated. individually controlled in the direction of In order to enable individual control of the segmented anodes 4, a child rectifier 7 is connected between the individual segmented anodes 4 and the cathode layer as means for individually controlling the quantity of electricity. The thickness at each position in the width direction of the copper foil can be easily measured by measuring the weight per unit area through appropriate sampling, or by winding up a thickness measuring device such as a capacitance sensing type. It can also be placed in the path to monitor the thickness and linked to the child rectifier 7 using a feedback device.

An insulating seal is preferably provided between each segmented anode. Insulating materials include PvC board, room temperature vulcanized rubber (RTV:
Product name) etc. can be used. In addition to this, it can also be achieved, for example, by joining adjacent divided anodes with an insulating adhesive or by integrating the divided anodes with an insulating film in between.

In this way, by using the device of the present invention, it is possible to make the thickness of the electrolytic copper foil produced uniform by using the divided anode for foil thickness uniformity and individually controlling the amount of electricity supplied thereto. .

Next, an example of use of the device of the present invention will be shown.

(Example 1) Using a cathode shell with a diameter of 2.0 m and a width of 1.3 m, and two anodes with a width of 1.3 m disposed along approximately the lower half of the cathode shell as shown. 35μ thick using copper sulfate solution
m copper foil was manufactured. As the anode structure according to the present invention, the structure shown in FIGS. 1 and 2 was used, and it was composed of 20 divided anodes. The weight per unit area of the peeled copper foil was measured and the weight of each anode was 0.1 to 1. OA/di
As a result, with the device of the present invention, the variation in the thickness in the width direction was reduced from the conventional variation of about 3% to 0.5% or less.

(Example 2) The anode structure according to the present invention is constructed by arranging 20 divided anodes on the existing anode on the drawer side of the copper foil shown in FIG. A copper foil with a thickness of 35 μm was manufactured. The thickness variation in the width direction of the obtained copper foil was 0.
．． It was less than 5%.

(Effects of the invention) 1. Conventionally, several anode corrections (partial scraping) were required to obtain the ideal foil thickness. Since there is an operating period of about 1 to 2 weeks between corrections, it used to take 3 to 4 weeks to complete the correction, but with the present invention, it is now possible to adjust the thickness even during operation. It has become possible to manufacture copper foil with good thickness.

2o The need to scrape the anode part, which was conventionally performed every time the anode was replaced, is eliminated or significantly reduced, so various burdens associated with equipment maintenance are reduced.

3. Furthermore, the device of the present invention makes it possible to correct variations in thickness in the longitudinal direction, which was previously impossible. Although the variation in the thickness in the length direction is caused by the structure of the cathode shell, it has periodicity and can be corrected by controlling the current conditions according to the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing the arrangement relationship between the cathode body and the anode in an embodiment in which a part of the anode on the copper foil drawer side of the two anodes is configured as a divided anode for equalizing the foil thickness. be. 2 is a perspective view of the anode of FIG. 1; FIG. FIG. 3 shows an example in which not only the copper foil draw-out side but also a part of the anode on the electrodeposition start side is configured as a divided anode for making the foil thickness uniform. FIG. 4 is an explanatory diagram showing the arrangement relationship between a cathode body and an anode in conventional electrolytic copper foil production. l: Cathode body 3: Anode 4: Split anode 5: Rectifier 7: Child rectifier! il1 figure 2 figure

Claims (1)

[Claims] 1) It is equipped with a rotatable cathode shell and at least one anode facing the cathode shell, an electrolyte is flowed between the cathode shell and the anode, copper is electrodeposited on the surface of the cathode shell, and In an electrolytic copper foil manufacturing apparatus for peeling electrodeposited copper foil from the cathode body, a part of the anode is configured as a plurality of foil thickness equalizing anodes divided in the width direction, and the foil thickness is uniform. An apparatus for manufacturing electrolytic copper foil, characterized by comprising means for individually controlling the amount of electricity supplied to the divided anodes.