JP4719375B2 - High speed electrodeposition drum and its manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-speed electrodeposition drum for producing a metal foil such as a copper foil or a nickel foil by an electrolytic plating method and a method for producing the same.
[0002]
[Prior art]
Electrolytic copper foil production equipment with electrodeposited titanium used for the production of metal foils centering on electrolytic copper foils for printed wiring boards has a rotating drum cathode at the center of a bathtub serving as a container for copper plating solution. Both ends are set by bearings, about 1/2 of the volume is immersed in a copper plating bath, and direct current is passed through a current collector ring and rectifier between the anode and the anode, and the plating bath As the copper surface begins to be plated on the titanium surface that has entered the bath from one side of the copper foil, the copper foil has a predetermined thickness until it comes out of the bath surface on the other side, and then is peeled off from the titanium surface and wound around the bobbin. Manufactured continuously.
[0003]
The conventional rotating drum cathode has a machine finish on the upper surface of a stainless steel or carbon steel inner drum constructed around the rotating shaft and fitted with a titanium outer drum as an electrodeposition surface by shrink fitting. Used after polishing.
[0004]
In recent years, stainless steel or carbon steel has been generally used as the support for the titanium outer drum, but in the past, as seen in Japanese Patent Publication Nos. 46-90 and 58-24507. It is made of lead or copper alloy having a thermal expansion coefficient larger than that of titanium, and the copper foil makes the current distribution on the electrodeposition surface uniform by improving the electrical contact with the titanium outer drum that is shrink-fitted into this. It has been proposed as being effective in reducing the variation in thickness of the film.
[0005]
[Problems to be Solved by the Invention]
In recent years, the demand for copper foil for printed circuit boards has increased, so in order to increase the productivity of copper foil, the existing electrodeposition drum will increase the current to the full capacity of the structure, and the new electrodeposition drum will It is now required to have a large current and high current density specification that is much larger than before. For example, what was conventionally 2.0 to 2.3 mφ × 50 A / dm ² has recently been required to have performance exceeding 2.7 to 3.0 mφ × 70 to 80 A / dm ² or 100 A / dm ² .
[0006]
Also, regarding the thickness of copper foil, the required thickness of copper foil for electronic device printed circuit with high precision has been required from 35 microns to 18 microns or less, or 10 microns or less. The variation of has come to be strictly asked.
[0007]
This increase in current has been progressed by various proposals for improving the contact between the inner and the outer in a general electrodeposition drum manufactured by shrink fitting a titanium outer drum on a conventional stainless steel or carbon steel inner drum. In spite of this, the lack of current capacity of the inner drum material and the lack of uniformity of shrink-fitting contact inevitably cause local heating of the electrodeposited surface and large variations in foil thickness. It has emerged as a new problem with the increase.
[0008]
Under these circumstances, the present inventors have developed a high-speed electrodeposition drum that can smoothly produce thin foils with no variation in thickness under high productivity and high current density required by copper foil manufacturers. It has been studied and tested as an issue.
[0009]
In general, a copper foil having no thickness variation is obtained from a cathode surface with a uniform current distribution. In order for the current distribution to be uniform, it is necessary to smoothly conduct the current flowing into the electrodeposition surface to the inner drum, which is the support, and to this end, the inner periphery of the outer drum that is shrink-fitted to the outer peripheral surface of the inner drum. It is required that the surface and the outer peripheral surface of the inner drum are completely fitted and the electric resistance of the entire shrink contact surface is uniform.
[0010]
In order to cope with a larger current, an inner drum that has a sufficiently large current capacity and electrical conductivity straight as much as possible to the current flowing perpendicularly to the electrodeposition surface of the titanium outer drum with small current capacity and electrical conductivity. It is necessary to conduct electricity.
[0011]
Therefore, the metal material composing the inner drum is not only mechanically strong as a support for the outer drum, but also has a sufficiently close contact with the outer drum so as to conduct the inner drum with uniform contact resistance. Therefore, it is necessary to have excellent characteristics of contact and conductivity. This necessity has already been proposed earlier, and the coefficient of thermal expansion is larger than that of titanium, which is the material of the outer drum on which lead is applied in Japanese Patent Publication No. 46-90, and copper or bronze alloy is applied in Japanese Patent Publication No. 58-24507. Therefore, it has been proposed for the reason that it expands and adheres to the inner peripheral surface of the outer drum at a high operating temperature to enhance the contact effect.
[0012]
The present inventors thought that it was necessary to review the material constituting the support body of the titanium outer drum at the present time when the demands for large current, high current density and thin foil were remarkably increased. The reason is that as the current increases, the electrical resistance of the structure constituting the electrodeposition drum increases, the tank voltage is increased to increase power loss, the drum temperature due to Joule heat, the plating bath temperature is increased, the drum and Contrary to the fact that it may be necessary to cool the circulating copper plating solution, if the entire support is made of copper or copper alloy having a low electrical resistance, the structure resistance can be minimized, so the power consumption leading to heat generation can be reduced. This is because it can easily be realized to save current capacity sufficient to accept a large current.
[0013]
That is, it is ideal that the entire support is made of copper or a copper alloy having the lowest electrical resistance and excellent conductivity. However, most of the inner drums of titanium electrodeposition drums commonly used today are made of stainless steel or carbon steel having a relatively high electrical resistance. The reason why copper or copper alloys have not been generally used for outer drum supports in recent years is that copper or copper alloys have a relatively high material cost, and the workability of welding and machine cutting as well as the mechanical strength of the structure. It is inferred that it is inferior to stainless steel or carbon steel, and that the production cost is high, which is mainly due to the relatively low current flow and the required current capacity.
[0014]
The present inventors have noted that copper or a copper alloy is a suitable material for the purpose of high current, but there are some problems in workability and economy, and stainless steel or carbon steel that is commonly used in recent years. As a result of investigating and gaining experience in constructing an outer drum support that adapts to high current and high current density by simple means, taking advantage of the advantages of Has been confirmed to be able to be stably produced without causing problems such as hot spots under a high current density, and the present invention has been completed.
[0015]
The copper or copper alloy in the present invention is not used as an intermediate material interposed between the outer peripheral surface of the outer drum and the outer peripheral surface of the inner drum as shown in, for example, Japanese Patent No. 3121775, but the support and conductive material of the titanium outer drum. As the main material of the inner drum structure as a body, the previous proposals were reviewed to solve the problems of workability, economy and effectiveness.
[0016]
[Means for solving problems]
Therefore, the gist of the present invention is as follows. In other words, Ri Do from the inner drum serving as titanium outer drum and its support, the support is an internal support is constructed of stainless steel or carbon steel, construction external support with a conductive supporting layer of copper or a copper alloy In the electrodeposited drum comprising a composite support , the conductive support layer is made of an external support formed by depositing copper or a copper alloy on the surface of an internal support made of stainless steel or carbon steel by thermal spraying or welding. It is a high-speed electrodeposition drum characterized by. Here, the conductive support layer may be an external support formed by shrink fitting a copper or copper alloy ring on the outer periphery of the stainless steel or carbon steel internal support, but the stainless steel or carbon steel support It is preferable to use an external support formed by depositing copper or a copper alloy on the surface of the internal support of the drum by thermal spraying or welding.
[0017]
Further, in the production of these conductive support layers , an outer support made of copper or copper alloy whose outer peripheral portion is machined and a tin coating layer on the surface thereof, and a platinum coating layer on the inner surface of the tin coating layer. When it comprises with the platinum coating layer obtained by carrying out shrink fitting of the titanium outer drum which it has, it will become a more preferable high-speed electrodeposition drum.
[0018]
Therefore, these high-speed electrodeposition drum, Ru can efficiently obtained Rukoto in following two manufacturing methods. That is, first of all,
1) The inner support which is an inner drum is formed of stainless steel or carbon steel,
2) A copper ring conductive ring is formed of a rolled copper plate or a copper alloy plate having a thickness sufficient to receive the current flowing into the electrodeposition surface, and it is shrink-fitted to the inner drum at a heating temperature that does not impair the physical properties of the copper material. Forming an external support,
3) After shrink fitting, machine the inner drum surface with copper as the surface to increase the surface accuracy, roundness and cylindricity,
4) Next, tin the copper surface for anticorrosion and good electrical contact,
5) Similarly, in order to obtain corrosion prevention and excellent electrical contact, an electrodeposition drum having a good conductive support layer is obtained by shrink fitting a titanium outer drum with an inner peripheral surface coated with platinum onto an inner drum coated with tin on a copper surface. It is a manufacturing method of the high-speed electrodeposition drum characterized by forming.
[0019]
Further, when manufacturing an electrodeposition drum comprising a titanium outer drum and an inner drum as a support thereof, the following changes may be made. According to this second method,
1) The inner support which is an inner drum is formed of stainless steel or carbon steel,
2) Form an external support by forming a build-up layer by thermal spraying or welding of copper or copper alloy to a thickness sufficient to receive the current flowing into the electrodeposition surface,
3) Machining the inner drum surface with the surface layered by thermal spraying or welding to improve surface accuracy, roundness and cylindricity,
4) Next, tin the copper surface for anticorrosion and good electrical contact,
5) Similarly, in order to obtain corrosion prevention and excellent electrical contact, an electrodeposition drum having a good conductive support layer is obtained by shrink fitting a titanium outer drum with an inner peripheral surface coated with platinum onto an inner drum coated with tin on a copper surface. The high speed electrodeposition drum manufacturing method is characterized in that it is formed.
[0020]
The machining of the inner drum copper surface and the tin coating on the inner peripheral surface of the titanium outer drum and the platinum coating on the inner peripheral surface of the titanium outer drum in the preceding items 3) to 5) are necessary means for further enhancing the effects of the present invention. That is, lead in JP-B-46-90, copper or copper alloy in JP-B-58-24507, or a recent proposal, that is, between the inner peripheral surface of the outer drum and the outer peripheral surface of the inner drum in Japanese Patent No. 3121775. Existing copper plate or copper alloy plate, conductive soft intermediate material exploding to the inner drum forming material in JP-A-2001-49482, etc., all have a higher thermal expansion coefficient than titanium of the material on the titanium surface facing this This is a factor that causes close contact.
[0021]
However, according to the experiments by the inventors, although the hardness of copper or copper alloy (H _B = 35 to 75) is smaller than that of titanium (H _B = about 120), the local contact in a narrow area is not possible. The outer drum and inner drum contact surfaces that have a large area contact, and the thermal expansion force at a temperature of 100 ° C or less is the same as that of carbon steel unless a large stress such as explosion welding is applied. In the same way, the phenomenon of close contact with the titanium surface of the outer drum does not occur, and it is basically inevitable that there will be a gap corresponding to the inner surface roughness of the titanium outer drum and the cylinder accuracy of the drum, although there is a difference in degree. I found out.
[0022]
This is supported by the proposal of Japanese Patent Publication No. 58-24507, which aims to improve the imperfection of the shrink-fit contact between the titanium outer drum and the inner drum. Mainly means not only to make high copper or copper alloy, but also to cut the concave and convex grooves on the surface of copper or copper alloy to reduce the surface area to 1/3 to increase the tightness of shrink fitting by 3 times to compensate for the lack of contact It is clear from the fact that
[0023]
In the present invention, an external support made of copper or copper alloy (FIGS. 3 and 9-2) integrated with an outer peripheral portion of a stainless steel or carbon steel internal support (FIGS. 3 and 9-1) of the inner drum internal support. Auxiliary means for machining the inner surface of the inner drum to complete the surface accuracy and cylindrical accuracy of the copper, tin-coating the copper surface, and shrink-plating the platinum-coated titanium outer drum is based on the temperature change of the copper-based conductive material. It was confirmed that the expansion and contraction of the changing volume compensates for the uncertainties of the means that makes contact an essential factor, and it has been confirmed that this enables stable high-current foil-making operation for a long period of time.
[0024]
As is clear from the above, the present invention proposes the above-mentioned proposal of Japanese Patent Publication No. 58-24507, that is, in order to improve the electrical contact with the titanium outer drum to be shrink-fitted, the entire inner drum is made of a copper alloy. In order to improve the workability and economic problems inherent in the proposal “to make”, the inner drum inner support mainly responsible for the strength of the support is made of stainless steel or carbon steel and is electrically necessary. By constructing only the outer peripheral portion of the outer support of copper or copper alloy, production of a high-speed electrodeposition drum having a large current and a high current density can be realized with advantageous workability and economy.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described by taking a titanium electrodeposition drum having a diameter of 2.7 m, a width of 1.3 m, and an energization current of 60,000 A as an example. FIG. 1 is a schematic front view of an electrolytic copper foil manufacturing apparatus. FIG. 2 is a partially broken front view of the titanium electrodeposition drum of the present invention, and FIG. 3 is a cross-sectional view showing details of a portion surrounded by A in FIG.
As shown in FIG. 1, an electrolytic copper foil manufacturing apparatus having a titanium electrodeposition surface used for manufacturing a metal foil centering on an electrolytic copper foil for a printed wiring board is the center of a bathtub 1 serving as a container for a copper plating solution. The rotary cathode type electrodeposition drum 2 is set at both ends of the rotary shaft 3 by bearings 4, and about 1/2 of the volume is immersed in a copper plating bath 5 between the anode 6 and facing the cathode. Then, a direct current is passed through the current collecting ring 7 and the rectifier 8, and copper begins to be plated on the titanium surface that has entered the bath from one side of the copper plating bath and has a predetermined thickness until it comes out of the bath surface on the other side. After becoming a copper foil, it is continuously manufactured as it is peeled off from the titanium surface and wound on a bobbin.
[0026]
Example 1
The titanium outer drum 10 shown in FIG. 2 is shrink-fitted onto the surface of the inner drum 9 to complete mutual electrical contact. However, in Example 1 of the present invention, the inner drum internal support 9-1 has a thickness of about A 20 mm stainless steel plate was formed to an outer diameter of about 2680 mm and a width of 1300 mm. Next, a rolled copper plate having a required thickness is roll-bended, both ends are butted, plasma-welded, and the inner diameter of the copper conductive ring is several mm smaller than the outer diameter of the stainless steel cylindrical inner support (FIGS. 3 and 9-1). An external support (FIGS. 3 and 9-2) was molded. Next, the copper ring was set vertically in a shrink-fitting furnace, and the entire surface was heated uniformly to raise the temperature to an appropriate temperature (in this case, about 200 ° C.). A stainless steel inner drum was inserted vertically into a copper ring that was expanded by heating to expand its inner diameter, and then radiated and shrink-fitted. Next, the surface of the copper ring integrated with the stainless steel inner drum is machined to cut a surface layer of several mm to form a conductive layer with the required thickness, and at the same time, a copper conductive layer with sufficient cylindricity and surface accuracy is formed on the surface layer. The inner drum is completed. Next, tin coating 11 was applied to the copper surface by a plating apparatus according to Japanese Patent No. 2927726.
On the other hand, an outer drum 10 having an inner diameter of about 2680 mm, which is a few mm smaller than the outer diameter of the inner drum having copper as the surface, is manufactured by a rolled titanium plate having a thickness of 8 mm, and the inner peripheral surface thereof is coated with platinum coating 12 according to Japanese Patent No. 2927726. After the formation, a high-speed electrodeposition drum was completed by shrink fitting with an inner drum having the tin-coated copper ring as a surface layer.
[0027]
Example 2
As in Example 1, a side plate and a rotary shaft were attached to a carbon steel cylinder having a thickness of about 20 mm to form an inner support 9-1 for the inner drum base, and then the outer surface of the copper-based conductive layer was formed on the surface in the following order. Support 9-2 was formed.
(A) It set to the surface treatment apparatus according to a copper foil plating apparatus, and it has arrange | positioned so that about 1/4 of a drum may be immersed in a process liquid bath.
(A) The surface of the carbon steel was degreased by applying an alkaline degreasing solution to the bathtub and rotating the drum for several hours.
(C) After removing the degreasing solution, the rotating surface was thoroughly washed with pure water and then dried with hot air.
(D) An etching solution containing sulfuric acid as a main component was put in the bath, and the surface of the rotating drum was etched for several hours to roughen the surface.
(E) The etching solution was extracted, and the surface was washed with water and dried.
(F) Set up a TIG welding machine using argon gas as the shielding gas, and repeat the build-up welding while rotating the drum sequentially from one side of the drum surface with the linear copper-based build-up material, and the copper layer of the required thickness An external support 9-2 was formed.
(G) Next, the drum is transferred to a machining device, the rough surface layer of the copper layer is cut, and the copper layer having the required thickness is finished. At the same time, the inner drum is made of a copper material having a sufficient roundness and cylindricity. completed.
(H) As in Example 1, the copper surface was coated with tin.
(K) On the other hand, an outer drum was manufactured from a titanium rolled plate having a thickness of 8 mm as in Example 1, and the inner peripheral surface thereof was coated with platinum, and then shrink-fitted on an inner drum having tin-coated copper as a surface. A high-speed electrodeposition drum was completed.
[0028]
【The invention's effect】
As described above, the inner drum as the outer drum support in the present invention, the inner support is made of stainless steel or carbon steel, the outer support of the surface layer portion that receives a large current is made of copper or a copper alloy, In addition, the surface of the inner drum is machined to ensure the cylindrical accuracy of the inner drum, and the tin coating that enhances the anticorrosion and electrical contact effect is applied, so the inner peripheral surface of platinum is excellent in electrical contact. The electrical performance of the electrodeposition drum completed by shrink-fitting the coated outer drum makes the current distribution on the titanium electrodeposition surface uniform, uniforming the copper foil thickness, and producing without causing hot spots and other obstacles High stability and high current density operation.
[Brief description of the drawings]
FIG. 1 is a schematic front view of an electrolytic copper foil manufacturing apparatus.
FIG. 2 is a partially broken front view showing a general electrodeposition drum structure in which an outer drum is shrink-fitted and joined to an inner drum and a joining interface.
FIG. 3 is an enlarged view corresponding to FIG. 2A, showing details of a shrink-fitted joint between a titanium outer drum whose inner peripheral surface is platinum-coated and an inner drum having a copper-based conductive layer whose outer peripheral surface is tin-coated. It is sectional drawing.
[Explanation of symbols]
1 Bathtub 2 Rotating Cathode Electrodeposition Drum 3 Rotating Shaft 6 Anode 9 Outer Plate of General Inner Drum
9-1 Inner drum internal support of the present invention
9-2 Inner drum external support of the present invention
10 Outer drum
11 Tin coating
12 Platinum coating

Claims (3)

Ri Do from the inner drum serving as titanium outer drum and its support, the support is an internal support is constructed of stainless steel or carbon steel, external supports are composed of a conductive supporting layer of copper or a copper alloy In an electrodeposition drum consisting of a composite support ,
The high-speed electrodeposition drum is characterized in that the conductive support layer comprises an external support formed by depositing copper or a copper alloy on the surface of an internal support made of stainless steel or carbon steel by thermal spraying or welding . When manufacturing an electrodeposition drum consisting of an outer drum made of titanium and an inner drum as its support,
1) The inner support which is an inner drum is formed of stainless steel or carbon steel,
2) A copper ring conductive ring is formed of a rolled copper plate or a copper alloy plate having a thickness sufficient to receive the current flowing into the electrodeposition surface, and it is shrink-fitted to the inner drum at a heating temperature that does not impair the physical properties of the copper material. Forming an external support,
3) After shrink fitting, machine the inner drum surface with copper as the surface to increase the surface accuracy, roundness and cylindricity,
4) Next, tin the copper surface for anticorrosion and good electrical contact,
5) Similarly, in order to obtain corrosion prevention and excellent electrical contact, an electrodeposition drum having a good conductive support layer is obtained by shrink fitting a titanium outer drum with an inner peripheral surface coated with platinum onto an inner drum coated with tin on a copper surface. A method for producing a high-speed electrodeposition drum characterized by comprising: When manufacturing an electrodeposition drum consisting of an outer drum made of titanium and an inner drum as its support,
1) The inner support which is an inner drum is formed of stainless steel or carbon steel,
2) forming an external support by forming a build-up layer by thermal spraying or welding of copper or copper alloy to a thickness sufficient to receive the current flowing into the electrodeposition surface;
3) Machining the inner drum surface with the surface of the thermal spraying or welding to increase the surface accuracy, roundness and cylindricity,
4) Next, tin the copper surface for anticorrosion and good electrical contact,
5) Similarly, in order to obtain corrosion prevention and excellent electrical contact, an electrodeposition drum having a good conductive support layer is obtained by shrink fitting a titanium outer drum with an inner peripheral surface coated with platinum onto an inner drum coated with tin on a copper surface. A method for producing a high-speed electrodeposition drum characterized by comprising:

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