JPH0693490A - Manufacture of electrolytic metallic foil - Google Patents

Abstract

PURPOSE:To provide a manufacturing method for an electrolytic metallic foil which easily uniformalizes the irregular thickness, particularly in the width direction thereof, at the time of energizing during the electrolization without interrupting the electrolization in obtaining an electrolytic metallic foil. CONSTITUTION:The electrolytic metallic foil 4 is manufactured by using an electrolytic metallic foil manufacturing device consisting of a cathode drum 1 rotating at constant speed and an anode 2 arranged so as to face thereto on the both side of the approximately lower half of the drum surface, energizing while supplying an electrolytic liquid into the spacing 7 between the both electrodes, electrodeposition-forming the metallic foil 4 having a prescribed thickness on the cathode drum surface and continuously winding up the metallic foil 4 to an outside take-up roll 5. In manufacturing the electrolytic metallic foil 4 in the above-mentioned manner, a part of at least one side anode surface is covered with an insulating material 6 having a prescribed shape in accordance with the metallic foil thickness distribution at the time of energizing, thereby uniformalizing the thickness of the electrolytic metallic foil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an electro-deposited metal foil having a uniform foil thickness. More specifically, it is possible to easily eliminate a non-uniform thickness in the width direction of the metal foil without interrupting energization during electrolysis. The present invention relates to a method for producing an electrolytic metal foil that can be manufactured.

[0002]

2. Description of the Related Art An electrolytic method is known as a method for mass-producing metal foil. In this electrolysis method, a plating solution is supplied to the gap between the two electrodes by using an electrolytic metal foil manufacturing apparatus composed of a cathode drum that rotates at a constant speed and an anode that is arranged to face each other on both sides of a lower half of the drum surface. While energizing, a metal foil having a predetermined thickness is electrodeposited on the surface of the cathode drum, and the metal foil is continuously wound outside to obtain an electrolytic metal foil.

In the electrolysis method, various metal foils can be obtained by appropriately selecting the metal ions of the plating solution. For example, pure metal foil such as copper foil, zinc foil, and nickel foil, and, for example, iron / nickel foil, nickel-cobalt foil, iron / cobalt foil, nickel-chromium-cobalt foil, nickel-
Binary and ternary alloy foils such as cobalt-iron foil can be obtained.

Thickness is a basic required property of the metal foil obtained by these electrolysis methods. It is important that the thickness is uniform without variation, and the requirements for making the thickness uniform are to keep the concentration, temperature, flow rate, pH, etc. of the plating solution supplied constant. Keep the gap between the cathode and anode (distance between the electrodes) constant. Keep the power supply constant. Keep the rotation speed of the cathode rotating drum constant. It is important to always keep these requirements.

However, when electrolysis is continuously carried out for a long time using the above-mentioned device, for example, lead, which is called an insoluble anode, lead alloy, platinum-coated titanium, etc. The thickness distribution, especially the thickness distribution in the width direction may vary. It is considered that this is because the gap between the positive and negative electrodes, which was initially set so as to obtain a uniform thickness, fluctuates. It is considered that the variation in the gap is caused by the local increase in the wear of the anode even in the insoluble anode, in proportion to the energization time, and this wear phenomenon tends to be remarkable at both ends of the anode. As a result, the current density per unit area to the cathode surface is affected, and both ends of the electrolytic metal foil become thinner than the central part, resulting in variation in the thickness distribution in the width direction. When the electrolysis is continued as it is, a thickness defect which is unacceptable in terms of quality occurs in the obtained metal foil.

Conventionally, as an operation for eliminating this thickness defect and making the thickness uniform, a series of steps such as stopping the energization, stopping the supply of the plating solution, and relocating the cathode drum to the outside of the electrolysis device are carried out. It has been performed to adjust the position of the anode plate or grind the anode surface for equalizing the thickness based on the thickness distribution data before stopping the energization. Therefore, the adjustment of the thickness requires a lot of time and labor in the above process, and it is inevitable to reduce the production amount due to the interruption of electrolysis.

According to Japanese Unexamined Patent Publication No. 4-36489-36494, the divided anodes for equalizing the foil thickness are used to individually control the amount of electricity supplied for each divided anode, or
It has been proposed to correct the thickness during operation by individually controlling the positions of the divided anodes. However, this prior art has an advantage that the thickness can be individually controlled by providing a large number of divided anodes, but on the other hand, electrical and structural troubles caused by a large number of divided anodes also increase, and the power supply There are problems that installation is expensive, maintenance is complicated and management is not easy, and if a problem occurs with one split anode, the operation will be forced to be interrupted.

[0008]

DISCLOSURE OF THE INVENTION In the present invention, in obtaining an electrolytic metal foil, it is possible to easily homogenize a non-uniform thickness in the width direction during electrolysis without interruption of electrolysis and during energization. An object of the present invention is to provide a method for producing a simple electrolytic metal foil.

[0009]

Means for Solving the Problems As a result of intensive studies by the present inventors in order to achieve the object of the present invention, as a result, during electrolysis, at least a part of the anode surface on one side at the time of energization, a metal for coating the surface. It has been found that an electrolytic metal foil having a uniform foil thickness can be obtained by providing an insulator having a predetermined shape according to the foil thickness distribution, and the present invention has been completed based on this finding.

That is, the present invention employs an electrolytic metal foil manufacturing apparatus composed of a cathode drum which rotates at a constant speed and an anode which is opposed to both sides of the lower half of the drum surface. Energizing while supplying the plating solution, electrodepositing a metal foil of a predetermined thickness on the cathode drum surface, in producing an electrolytic metal foil by continuously winding this on an external winding roll, at the time of energizing, A method for producing an electrolytic metal foil, characterized in that at least a part of the anode surface on one side is covered with an insulator having a predetermined shape according to the metal foil thickness distribution to make the thickness of the electrolytic metal foil uniform. Is.

The method for producing an electrolytic metal foil of the present invention is preferably used as a method for producing an electrolytic copper foil among the various electrolytic metal foils described above.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a cross-sectional view of an electrolysis apparatus for continuously producing an electro-deposited metal foil, illustrating an example of a state in which an insulator used in the method of the present invention is provided above one side of an anode surface.

FIG. 2 is a plan view of FIG.

FIG. 3 is a perspective view of the anode on one side shown in FIGS. 1 and 2, and illustrates an example in which an insulator used in the method of the present invention is provided above the anode surface.

In FIGS. 1 to 3, the electrolytic metal foil is manufactured as follows.

A cathode drum 1 made of a metal selected from stainless steel, titanium, titanium alloy, or the like, which rotates at a constant speed (counterclockwise rotation in the direction of arrow in FIG. 1) and a lower half of the drum surface are disposed so as to face each other. For example, by using an electrolysis device composed of an insoluble arc-shaped anode 2 made of a metal selected from lead, lead alloy, platinum, etc., the gap 7 between the positive and negative electrodes is made constant, and the plating liquid is placed in the gap 7. Supply a fixed amount. As the plating solution, a plating solution containing metal ions capable of electrodepositing a desired metal foil is appropriately selected.

In the present invention, when the metal foil is a copper foil, an acidic copper sulfate plating solution is preferably used.

When a direct current is applied while supplying the plating solution, the metal foil 4 is electrodeposited on the surface of the cathode drum 1 and the obtained metal foil 4 is wound on an external winding roll 5.

The thickness of the metal foil depends on the rotational speed of the cathode drum,
When other conditions such as plating solution concentration and temperature are constant, it is proportional to the amount of current to be passed, but other conditions including the current are constant, and by adjusting the rotation speed of the cathode drum,
A metal foil having a desired appropriate thickness can be easily obtained.

The method of the present invention uses, for example, an electrolytic metal foil manufacturing apparatus as shown in FIG.
The present invention is applied to various pure metal foils such as a copper foil, zinc foil, and nickel foil having a thickness of 00 μm, and a method for producing the above alloy foil by continuously electrolyzing, and particularly, the thickness of the metal foil in the width direction. When the variation occurs in the metal foil, this is eliminated to obtain a metal foil having a uniform thickness. The method of the present invention is carried out as follows.

In the method of the present invention, at the time of energization during electrolysis, at least a part of the anode surface on one side of the anode 2 in the electrolytic cell 3 is made into an insulator 6 having a predetermined shape according to the thickness distribution of the metal foil 4.
The thickness of the metal foil is controlled by coating with. The thickness distribution of the metal foil is previously measured during electrolysis, and an insulator is provided when the thickness distribution is not uniform. For the measurement of the thickness of the metal foil, for example, at the time of measuring the thickness in the width direction, at least three positions of both ends and the central part are measured, and if necessary, 10 or more positions are finely measured. It is convenient to determine the shape and size of the insulator, which will be described later, by setting the measurement points at the same intervals at this time. Thickness measuring means include non-destructive / non-contact type film thickness meter, micrometer, and gravimetric method to calculate the weight of a certain area and calculate from the unique density of each metal. Considering the required quality level of thickness. Therefore, an appropriate means can be selected. For example, in the case of an electrolytic copper foil for a printed wiring board, the thickness can be easily measured by the gravimetric method. The gravimetric method is a method in which a predetermined portion of an electrolytic copper foil is cut out, and the weight of the cut out portion is measured to measure the thickness distribution.

The shape and size of the insulator are determined according to the thickness distribution, and typical examples of the shape include a triangle, a semicircle, a circle, a trapezoid, and a band. These various shapes and sizes are available. By covering a part of the anode surface with an insulating material, the current density per unit area of the cathode surface can be reduced and the thickness of the portion where the insulator is installed can be reduced.

Further, it is desirable that the surface of the material of the insulator is a non-conductor and that it has excellent mechanical strength, heat resistance and chemical resistance. For example, plastics are used, of which hard vinyl chloride, polyethylene, polypropylene, PTFE (polytetrafluoroethylene), acrylic resin and the like are preferably used. Also,
A metal plate coated with a non-conductive resin, for example, a fluororesin, an epoxy resin, or the like, an insulating tape, a resist ink for plating, or the like may be used. Alternatively, a titanium plate having a non-conductive surface can also be used.

The thickness of the insulator is preferably about 0.02 to 20 mm, though it depends on the gap between the positive and negative electrodes, and it is particularly preferably 0.1 to 10 mm in practical use in consideration of fabrication processing, handling strength and the like.

Further, the size of the insulator corresponds to the covering area of the anode surface covered with the insulator, and considering the cost increase resulting from the voltage increase, the covering area is 20 of the total area of the anode.
% Or less, and particularly preferably 10% or less.

It is desirable that the insulator is provided so as to be adhered to at least one side of the anode surface along the curved surface of the anode so as to be connected to an external fixing means (not shown). It is desirable that an insulator having a shape and a size can be freely provided according to variations in thickness.

Next, the thickness distribution data of the metal foil obtained during electrolysis and the shape of the insulator produced based on the data will be described with reference to FIG. 4, but the shape of the insulator is not limited to these.

FIG. 4 shows a basic example of the thickness distribution in the width direction of the electro-deposited metal foil before providing an insulator when the method of the present invention is carried out, and an example of an insulator shape produced corresponding to this. It is explanatory drawing illustrated by the perspective view provided in a part of anode surface.

Referring to FIG. In the thickness distribution example of No. 1, the thickness of the left end portion, the central portion, and the right end portion (positions shown in FIG. 2) of the metal foil in the width direction is measured at three points, and the tendency is shown. In the case of this example, the thickness is varied such that the left end portion> the central portion> the right end portion. Therefore, the thickness of the region having a large thickness (left end portion) is reduced and the thickness of the region having a small thickness (right end portion) is reduced. It is possible to make it uniform by increasing the size. Therefore, the shape of the insulator corresponding to this is a triangular insulator 61 that maximizes the coverage area of the anode surface corresponding to the thickness of the left end portion and minimizes the anode coverage area corresponding to the thickness of the right end portion. And coating the anode surface, the current density distribution on the cathode surface around the coating portion is left end portion <center portion <right end portion,
The thickness distribution of the metal foil formed by electrodeposition is adjusted by this, and the left end portion = the central portion = the right end portion can be made uniform in thickness distribution.

No. No. 2 is the thickness distribution example. No. 1 is an example showing the reverse tendency of No. 1. Based on the same idea as in 1,
Insulator 62 was produced and No. As in No. 1, it is provided by covering the anode surface.

No. 3, No. The thickness distribution example of No. 4 is an example in which the thickness of both end portions is larger or smaller than that of the central portion.
o. Insulators 63 and 64 were produced based on the same idea as in No. 1, and No. As in No. 1, it is provided by covering the anode surface.

No. 5, No. No. 6 shows an example in which one of both ends has a large thickness and one of the center part and both ends has substantially the same thickness. Insulator 65 or 66 is produced based on the same idea as in No. 1, and N
o. Similar to No. 1, it is provided by covering a part of the anode surface.

No. 1-No. The position of the insulator provided on the anode surface illustrated in 6 covers a part or the whole of the upper part of the anode surface, but is not limited to the upper part. For example, the strip-shaped insulators 67 and 68 which reach from the upper part to the lower part of the anode surface are manufactured and No.
5, No. Even with the coating corresponding to the thickness distribution example of No. 6, almost the same effect of thickness distribution as above can be obtained.

[0035]

EXAMPLE A sulfuric acid-copper sulfate plating solution (using a titanium cathode drum: diameter 100 cm, width 150 cm, anode: 2 sheets made of lead alloy, distance between electrodes 2 cm, drum rotation speed 20 m / h) shown in FIG. Temperature: 45 ° C, Concentration: Copper sulfate 30
0 g / l, sulfuric acid 80 g / l, gelatin 5 ppm) is supplied to the gap between both electrodes at a flow rate of 120 l / min to supply electricity, and copper obtained by peeling from the cathode drum during continuous production of an electrolytic copper foil having a set thickness of 30 μm The foil was taken as a sample for measuring the width-direction thickness distribution. This was cut into 5 points from the end (left end) to the right end at the same interval from the center to the right end, and each thickness was determined by the gravimetric method. The thickness distribution is as shown in FIG. It was The thickness distribution of the copper foil during the production shows that both ends are thicker than the center part, and the maximum thickness (the left end part 30.8μ
m) -minimum thickness (central part 29.3 μm) = 1.5 μm. The average thickness was 30.2 μm.

Therefore, based on the thickness distribution data shown in FIG. 5, a hard vinyl chloride material having a plate thickness of 2 mm is used as an insulator,
This was formed into a shape having a depression in the center as shown in FIG. 6 and processed so that it could come into contact with the curved surface of the anode.
In order to cover the upper portion of the anode surface on the final thickness side, this insulator was inserted along the anode surface through the gap between both electrodes, and fixed by being connected to an external fixing means (not shown).

Then, after the cathode drum rotated approximately once from the insertion position, a sample for measuring the thickness distribution in the width direction was sampled again in the same manner as above, and the thickness was measured.
The thickness distribution in the width direction as shown in (3) was obtained.

In this distribution chart (FIG. 7), the maximum thickness (left end portion 30.3 μm) -minimum thickness (center portion 29.8 μm) =
The average thickness was 0.5 μm and the average thickness was 30.08 μm. The thickness variation is relative to the set thickness (30 μm)
Before the method of the present invention was 5%, it was 1.7% after the method of the present invention. As can be seen from FIG. 7, the thicknesses are averaged and a uniform width-direction thickness distribution is obtained. It was confirmed that the copper foil was continuously produced without interruption of electrolysis.

[0039]

As is apparent from the above description, in the continuous method for producing an electrolytic metal foil by rotating the cathode drum, conventionally, when an abnormality was found in the thickness distribution, the energization was stopped and the plating solution In order to make the thickness uniform, it was essential to stop the supply, remove the cathode drum from the electrolysis device, and successively perform steps such as grinding adjustment of the anode surface.
On the other hand, if the method of the present invention is applied, the complicated steps described above can be omitted, and by providing an insulator on a part of the anode surface during the electrolytic operation, the thickness distribution of the electrolytic metal foil can be made uniform. It became possible to do.

This enables continuous operation without stopping the operation other than the regular periodical inspection work, which greatly contributes to not only the improvement of quality but also the increase of production amount and the improvement of yield. It is a thing. Especially in the production of electrolytic copper foil for printed wiring boards that require excellent thickness accuracy,
The method of the present invention has proven to be extremely useful.

[Brief description of drawings]

FIG. 1 is a sectional view of an electrolysis apparatus for continuously producing an electro-deposited metal foil.

FIG. 2 is a plan view of FIG.

FIG. 3 is a perspective view showing an anode on one side shown in FIGS. 1 and 2.

FIG. 4 is an explanatory view illustrating a basic example of a thickness distribution of a metal foil in a width direction and a shape of an insulator produced corresponding to the basic example.

FIG. 5 is a diagram showing a thickness distribution of a metal foil before carrying out the method of the present invention.

6 is a perspective view showing a state in which an insulator is provided above the anode surface by applying the method of the present invention, corresponding to the thickness distribution of the metal foil in FIG.

7 is a diagram corresponding to the thickness distribution of the metal foil of FIG. 5 and showing the thickness distribution of the metal foil after the insulator shown in FIG. 6 is provided.

[Explanation of symbols]

 1 Cathode drum 2 Anode 3 Electrolyzer 4 Metal foil 5 Winding roll 6 Insulator 7 Gap 61-68 Insulator

Claims (2)

[Claims] 1. A plating solution is applied to a gap between the two electrodes by using an electrolytic metal foil manufacturing apparatus including a cathode drum that rotates at a constant speed and an anode that is opposed to both sides of a lower half of the drum surface. While supplying electricity, a metal foil having a predetermined thickness is electrodeposited on the surface of the cathode drum, and an electrolytic metal foil is manufactured by continuously winding this on an external winding roll. A method for producing an electrolytic metal foil, characterized in that a part of the anode surface is covered with an insulator having a predetermined shape according to the metal foil thickness distribution to make the thickness of the electrolytic metal foil uniform. 2. The method for producing an electrolytic metal foil according to claim 1, wherein the electrolytic metal foil is a copper foil.