KR20220053720A - Rotating cathode drum for thin film manufacturing and its manufacturing method - Google Patents

Abstract

The present invention relates to a cylindrical rotating cathode drum having an inner space and, more particularly, to a rotating cathode drum for manufacturing a thin film. In the rotating cathode drum, a titanium layer is stacked on a metal layer. Moreover, the titanium layer comprises a direct energy deposition (DED) titanium layer formed by laminating titanium powder or titanium alloy powder on an outer surface using a DED method. According to an embodiment of the present invention, a welded part does not exist or the welded part is not exposed on an outer surface such that a crystal grain is fine and uniform in a size. Therefore, a rotating cathode drum for manufacturing a thin film has effects of having an excellent quality of a thin film produced thereby, allowing a rotating cathode drum to be easily used, and having excellent corrosion resistance.

Description

Rotating cathode drum for thin film manufacturing and its manufacturing method

The present invention relates to a rotating cathode drum for manufacturing a thin film and a method for manufacturing the same.

In general, an electrolytic copper thin plate is widely used as a substrate material for a printed circuit board (PCB) used in the electrical and electronic industries, and is a slim notebook computer, personal digital assistant (PDA), e-book, MP3 player. The demand is rapidly increasing centering on small products such as players, next-generation mobile phones, and ultra-thin flat panel displays.

Recently, the light, thin, and compact of electrical and electronic devices is accelerating, and accordingly, the circuits built into the devices are also being miniaturized. Accordingly, circuits formed on the PCB are also becoming thinner and thinner. Accordingly, the thin electrodeposited copper plate is also being made into an ultra-thin plate, and the importance of high-quality electrolytic copper thin plate is increasing.

Such an electrolytic copper thin plate is manufactured by a general apparatus including a rotating cathode drum and a rotating cathode drum and an anode electrode immersed in an electrolytic cell at regular intervals.

However, depending on the quality and performance of the rotating cathode drum of the milling machine, the thickness and surface grain size of the copper foil become non-uniform, resulting in a deviation in the width and weight of the copper foil in the grinding direction.

And the welding bead mark of the pipe pipe in the longitudinal direction of the pipe joint of the cathode drum is transferred in the width direction of the electrolytic copper foil.

As a result, discoloration such as unevenness occurs, and hot spot defects occur in the high current density operation range, thereby greatly reducing the quality of the copper foil.

1 is a configuration diagram schematically showing a manufacturing apparatus for manufacturing a general electrolytic copper thin plate.

As shown in FIG. 1, a general electrolytic copper thin plate manufacturing apparatus includes an electrolytic cell in which an electrolyte is accommodated, a rotating negative electrode drum rotating while a part thereof is submerged in the electrolyte contained in the electrolytic bath, and the rotation along the shape of the rotating negative electrode drum and an anode electrode disposed in the electrolyte at a predetermined distance from the cathode drum.

Typically, the electrolyte solution is a copper sulfate solution containing sulfuric acid, copper ions and chlorine ions, and has strong acid properties. The electrolyte is supplied and circulated at a relatively high speed in the electrolytic cell in order to prevent a deficiency of copper ions in the vicinity of the rotating cathode drum.

In addition, the surface material of the rotating cathode drum is composed of titanium, which maintains acid resistance to the electrolyte and facilitates the peeling of the thin electrodeposited copper plate. In such a configuration, when a high-density current is applied between the rotating cathode drum charged with negative potential and the anode electrode charged with positive potential using the electrolyte as a medium, the positively charged copper contained in the electrolyte is transferred to the rotating cathode drum. It becomes hard and thus solidifies and precipitates as a solid.

The deposited copper is made into a thin electrodeposited copper plate in the form of a metal thin film along the surface of the rotating negative electrode drum, and the electrolytic copper plate is wound around a bobbin under the guidance of guide rolls.

Figure 2 is a view schematically showing a rotating cathode drum of the electrolytic copper thin plate manufacturing apparatus according to the prior art.

As shown in Fig. 2, the rotating cathode drum is composed of an inner cylinder and an outer drum whose outer shell is made of titanium while surrounding the inner cylinder.

The inner drum and the outer drum are formed by pipe-forming a flat plate into a circular shape, bending, welding both ends to connect the welded part, forming the drum cylinder, and then mechanically fitting the inner cylinder to the outer cylinder by shrink-fitting. is made by

However, as described above, since the inner/outer drum is connected by the welding part, various problems have occurred due to the difference in structure and mechanical properties between the base material and the welding part. In particular, due to the presence of a weld, the grains are relatively coarse and non-uniform, and thus corrosion and deposition of the metal foil become non-uniform.

Accordingly, the inventors of the present invention conducted a study on a new method for manufacturing a rotating negative electrode drum in which the size of crystal grains are fine and uniform by controlling the welding part of the rotating negative electrode drum.

[Patent Document 1] Registered Patent Publication No. 10-0917278 (2009. 09. 07.): Electroplating method of negative electrode current collector plate of secondary battery using continuous pole method [Patent Document 2] Registered Patent Publication No. 10-0750314 (2007. 08. 10.): Mesh-type negative electrode drum for precision electric pole and manufacturing method thereof [Patent Document 3] Registered Patent Publication No. 10-1242374 (2013. 03. 05.): Manufacturing method of a rotating cathode drum

An object of one aspect of the present invention is to provide a rotating cathode drum for manufacturing a thin film in which there is no weld or the weld is not exposed on the outer surface.

In order to achieve the above object, in one aspect of the present invention

In the cylindrical rotating cathode drum having an inner space,

The rotating cathode drum has a titanium layer laminated on a metal layer,

The titanium layer is provided with a rotating cathode drum for thin film manufacturing, characterized in that it includes a DED titanium layer formed by laminating a titanium powder or a titanium alloy powder on an outer surface by a direct energy deposition method.

In addition, in another aspect of the present invention

In the method of manufacturing a rotating cathode drum for thin film production comprising the step of forming a titanium layer on a metal layer,

The forming of the titanium layer on the metal layer may include laminating a titanium powder or a titanium alloy powder in a direct energy deposition method;

There is provided a method for manufacturing a rotating cathode drum for thin film production, comprising:

Furthermore, in another aspect of the present invention

the rotating cathode drum;

positive electrode; and

electrolyte;

There is provided a thin film manufacturing apparatus comprising a.

In the rotating cathode drum for thin film production provided in one aspect of the present invention, the size of the crystal grains is finer and more uniform because there is no welding part or the welding part is not exposed on the outer surface, so that the quality of the thin film produced is excellent, and the rotation The negative electrode drum is easy to reuse and has the effect of excellent corrosion resistance.

1 shows a schematic diagram of a general thin film manufacturing apparatus using electro-deposition,
Figure 2 shows a schematic diagram of a rotating cathode drum for thin film production according to the prior art,
3 is a schematic diagram of a rotating cathode drum for manufacturing a thin film according to an embodiment of the present invention;
4 schematically shows a titanium layer of a rotating cathode drum for thin film production according to an embodiment of the present invention;
5 schematically shows a titanium layer of a rotating cathode drum for thin film production according to a comparative example of the present invention;
6 is a schematic diagram and SEM image of a cross-section viewed from above of a titanium layer of a rotating cathode drum for thin film production according to an embodiment of the present invention;
7 is a schematic diagram and an SEM image of a cross-section viewed from above of a titanium layer of a rotating cathode drum for thin film production according to a comparative example of the present invention;
8 is a schematic diagram and SEM image of a cross-section viewed from the side of a titanium layer of a rotating cathode drum for thin film production according to an embodiment of the present invention;
9 is a schematic diagram and SEM image of a cross-section viewed from the side of a titanium layer of a rotating cathode drum for thin film production according to a comparative example of the present invention;
10 shows an SEM image of the microstructure of a titanium layer of a rotating cathode drum for thin film production according to a comparative example and an embodiment of the present invention;
11 shows an SEM image of a microstructure after performing a corrosion test in a sulfuric acid environment on a titanium layer of a rotating cathode drum for thin film production according to a comparative example and an embodiment of the present invention.

Since the present invention can make various changes and thus various embodiments can be made, specific embodiments will be presented below and described in detail.

In addition, all terms in the present specification that are not specifically defined may be used in a meaning that is understandable to those of ordinary skill in the art to which the present invention pertains.

However, it should be understood that the present invention is not intended to be limited only to the specific embodiments to be described below, and includes all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Accordingly, there may be other equivalents and modifications to the embodiment described herein, and the embodiment presented herein is only the most preferred embodiment.

In one aspect of the invention

In the cylindrical rotating cathode drum having an inner space,

The rotating cathode drum has a titanium layer laminated on a metal layer,

The titanium layer is provided with a rotating cathode drum for thin film manufacturing, characterized in that it includes a DED titanium layer formed by laminating a titanium powder or a titanium alloy powder on an outer surface by a direct energy deposition method.

Hereinafter, the rotating cathode drum for thin film production provided in one aspect of the present invention will be described in detail for each configuration.

The rotating cathode drum 100 for producing a thin film provided in one aspect of the present invention has a cylindrical shape having an inner space.

The thin film may be a copper foil.

In addition, the rotating cathode drum has a form in which a titanium layer 110 is laminated on a metal layer 120 .

The metal layer may include at least one material selected from the group consisting of titanium, copper, stainless steel, carbon steel, and aluminum.

The metal layer may be used to increase electrical conductivity, decrease surface contact resistance, and increase adhesion.

The titanium layer may include a DED titanium layer 112 formed by laminating a titanium powder or a titanium alloy powder on an outer surface by a direct energy deposition method.

The titanium layer may be used to maintain corrosion resistance to an electrolyte used in manufacturing the thin film and to facilitate peeling of the manufactured thin film.

The titanium layer may be made of the DED titanium layer, or may have a DED titanium layer stacked on the titanium base material layer 111 including the welding part 111b.

That is, conventionally, a titanium layer consisting of a titanium base material layer including a welding part was used in a laminated form on a metal layer. The concept of coating is presented.

The DED titanium layer should be stacked in a direct energy deposition method.

This direct energy lamination is a method in which powder is sprayed from the top of the molding unit and melted at the same time in an atmospheric atmosphere, and there is no restriction on the size and atmosphere of the chamber, so there is an advantage in the molding of large parts and desired local parts compared to other 3D printing processes.

Another 3D printing method, the Power Bed Fusion (PBF) method, covers the entire part with powder and then melts it by irradiating energy to the desired area using a laser or electron beam. Since it is practically impossible in terms of process structure because it requires a very large amount of powder and equipment that can cover all large parts with powder, it is more preferable to perform 3D printing using the direct energy lamination method. Do.

In the present invention, by applying a DED titanium layer in which titanium powder or titanium alloy powder that does not require a separate welding part is stacked on the outer surface of the rotating cathode drum in a direct energy deposition method, the microstructure can be more uniform. there is. The more uniform the microstructure is, the easier it is to reuse after processing.

The average size of the grains of the DED titanium layer may be 1 μm to 100 μm. The finer the size of the crystal grains, the thinner the thin film can be produced and the quality of the produced thin film can be improved.

In detail, the size of the prior beta grain may be 15 μm to 30 μm, and the fine alpha lamellar therein may have a layered structure of several μm.

In addition, the microstructure of the DED titanium layer may be controlled to an equiaxed crystal structure of 1 μm to 100 μm through heat treatment.

In the case of the titanium layer 110 of the conventional rotating cathode drum, the welding portion 111b is exposed on the outer surface, and the welding portion has relatively coarse grains of several hundred μm or more. In addition, due to the difference in microstructure and mechanical properties with the titanium base material 111a, the microstructure is not uniform, and corrosion is also not uniform.

On the other hand, in the case of the present invention, since the welding part is not located on the outer surface, the microstructure is uniform and the crystal grain size is fine, so it is easy to reuse after processing, and the corrosion is also uniform. Equal current density is maintained for a long period of time, enabling uniform deposition of thin films. In addition, there is also an advantage that the thin film can be produced.

In addition, the iron content of the DED titanium layer may be 0.03 wt% or less, and the hydrogen content may be 60 ppm or less.

In addition, the iron content of the DED titanium layer may be 0.3 wt% or less, and the hydrogen content may be 0.015 wt% or less.

When the iron content of the DED titanium layer exceeds 0.3 wt%, the β-phase, which is relatively vulnerable to corrosion, is formed under the influence of Fe, which is a β-phase stabilizing element, and corrosion resistance may occur, and the hydrogen content is 0.015 wt%. If it is exceeded, there may be a problem that titanium hydrate may be excessively generated, which greatly affects the deterioration of corrosion resistance and mechanical properties.

In addition, in another aspect of the present invention

In the method of manufacturing a rotating cathode drum for thin film production comprising the step of forming a titanium layer on a metal layer,

The forming of the titanium layer on the metal layer may include laminating a titanium powder or a titanium alloy powder in a direct energy deposition method;

There is provided a method for manufacturing a rotating cathode drum for thin film production, comprising:

Hereinafter, a method for manufacturing a rotating cathode drum for thin film manufacturing provided in another aspect of the present invention will be described in detail.

A method for manufacturing a rotating cathode drum for thin film manufacturing provided in another aspect of the present invention includes forming a titanium layer on a metal layer.

The forming of the titanium layer on the metal layer includes laminating a titanium powder or a titanium alloy powder in a direct energy deposition method.

The average particle size of the titanium powder or titanium alloy powder may be 10 μm to 300 μm, and more specifically, 20 μm to 200 μm.

In the case of the direct energy lamination, a laser may be used as the melting heat source, but is not limited thereto, and a heat source commonly used in the field may be used.

In addition, in the case of direct energy lamination, the output of the heat source, the scan speed, etc. may be appropriately adjusted as necessary.

As described above, the titanium layer may be made of the DED titanium layer, or may have a form in which the DED titanium layer is laminated on the titanium base material layer including the welding part.

When the titanium layer is made of the DED titanium layer, the step of laminating a titanium powder or a titanium alloy powder by a direct energy deposition method may be performed on the metal layer.

Alternatively, when the titanium layer is in a form in which the DED titanium layer is laminated on the titanium base material layer 111 including the welding part 111b, titanium powder or titanium alloy powder is laminated in a direct energy deposition method. The step may be performed on the titanium base material layer. In this case, the step of forming the titanium layer on the metal layer is, before the step of laminating the titanium powder or titanium alloy powder in a direct energy deposition method, a titanium layer including a welding part is welded on the metal layer. It may further include the step of forming.

This direct energy lamination is a method in which powder is sprayed from the top of the molding unit and melted at the same time in an atmospheric atmosphere, and there is no restriction on the size and atmosphere of the chamber, so there is an advantage in the molding of large parts and desired local parts compared to other 3D printing processes.

Another 3D printing method, the Power Bed Fusion (PBF) method, covers the entire part with powder and then melts it by irradiating energy to the desired area using a laser or electron beam. Since it is practically impossible in terms of process structure because it requires a very large amount of powder and equipment that can cover all large parts with powder, it is more preferable to perform 3D printing using the direct energy lamination method. Do.

In the case of the conventional method of manufacturing a rotating cathode drum, the welding portion is exposed to the outer surface using only welding when the titanium layer is formed, and the welding portion has relatively coarse grains of several hundred μm or more. In addition, due to the difference in microstructure and mechanical properties with the titanium base material, the microstructure is not uniform, and corrosion is also not uniform.

On the other hand, in the case of the present invention, when the titanium layer is formed, the DED titanium layer is formed on the outermost surface by using the Direct Energy Deposition method, so that the welding part is not located on the outer surface, so that the microstructure is uniform and the grain size is uniform. Since the size is fine, it is easy to reuse after processing, and the corrosion is also uniform, the electrical conductivity is excellent and the equal current density on the surface of the cathode drum is maintained for a long period of time, so that a uniform deposition of a thin film is possible. In addition, there is also an advantage that the thin film can be produced.

Furthermore, in another aspect of the present invention

the rotating cathode drum 100;

anode electrode 200; and

electrolyte 300;

A thin film manufacturing apparatus 1000 comprising a is provided.

Hereinafter, the thin film manufacturing apparatus provided in another aspect of the present invention will be described in detail for each configuration. However, since the rotating cathode drum is the same as described above, the description will not be repeated.

A thin film manufacturing apparatus provided in another aspect of the present invention includes an anode electrode and an electrolyte.

The anode electrode may be immersed in the electrolyte at a predetermined distance from the rotating cathode drum and disposed.

The rotating cathode drum may be rotated with a part submerged in the electrolyte.

When the thin film is a copper foil, the electrolyte may include a copper sulfate solution containing sulfuric acid, copper ions, and chlorine ions. The electrolyte may have strong acid properties.

The electrolyte is supplied and circulated at a relatively high speed in order to prevent a copper ion deficiency in the vicinity of the rotating cathode drum.

As described above, the surface of the rotating cathode drum includes titanium that maintains acid resistance to the electrolyte and facilitates peeling of the thin film.

In this configuration, when a high-density current is applied between the rotating cathode drum charged with negative potential and the anode electrode charged with positive potential using the electrolyte as a medium, the copper in the cation state contained in the electrolyte is transferred to the rotating cathode drum. It becomes electrodeposited, and thus coagulates and precipitates into a solid.

The deposited copper is made into a thin metal film along the surface of the rotating negative electrode drum, and the rolled copper foil is wound on a bobbin under the guidance of guide rolls.

Hereinafter, the present invention will be described in more detail through Examples and Experimental Examples. The scope of the present invention is not limited to specific embodiments, and should be construed according to the appended claims. In addition, those skilled in the art will understand that many modifications and variations are possible without departing from the scope of the present invention.

<Example 1>

As shown in FIG. 4 , a test piece was prepared in which a DED titanium layer formed by laminating titanium powder on a base material layer welded by welding between base materials by a direct energy deposition method was prepared.

When actually applied to a cylindrical rotating cathode drum, the test piece may be applied in a shape that surrounds the cylindrical circumferential direction.

Pure titanium ASTM Gr.2 (O ≤ 0.25 wt.%, Fe ≤ 0.3 wt.%) powder was used for lamination of the titanium layer, and the size of this powder was at least 45 μm and at most 150 μm. A laser was used as a heat source for melting the powder, and the DED process conditions at this time were a laser power of 380 W and a scan speed of 0.85 m/min. In order to completely enclose the weld bead, it was molded to a width of 300 mm and a length of 600 mm, and a final 2.5 mm thick test piece was produced by laminating a total of 10 layers at 250 μm per layer.

<Comparative Example 1>

As shown in FIG. 5, a test piece composed of a base material layer welded between base materials by welding was prepared.

When actually applied to a cylindrical rotating cathode drum, the test piece can be applied in a shape that surrounds the cylindrical circumferential direction.

The welding part was manufactured using TIG (Tungsten Inert Gas) welding, which is most commonly used for titanium welding, and the process conditions at this time were 80 A, 12 cm/min. The size of the weld bead of the TIG welding test piece was observed to be 12.3 mm wide and 4.5 mm deep.

<Experimental Example 1> Morphology analysis

For the test pieces of Example 1 and Comparative Example 1, the microstructure was analyzed.

Schematic diagrams and SEM images of the cross-section viewed from above and the cross-section viewed from the side of the test piece of Example 1 can be confirmed through FIGS. 6 and 8, respectively, and schematic diagrams of the cross-section viewed from the top and the cross-section viewed from the side of the test piece of Comparative Example 1 and SEM images can be confirmed through FIGS. 7 and 9, respectively,

As can be seen in FIGS. 6 to 9 , the size of the crystal grains of Example 1 is several μm to several tens of μm, and, as can be seen in FIG. It can be seen that this was formed.

That is, in the case of Example 1, it can be confirmed that the size of the crystal grains of Comparative Example 1 of several hundred μm to several mm is much smaller than the size.

In addition, in the case of a cross-section viewed from above that is located on the outer surface when actually applied to a cylindrical rotating cathode drum, it can be confirmed that the microstructure of Example 1 is much more uniform than that of Comparative Example 1 as can be seen in FIGS. 6 and 7 . there is.

<Experimental Example 2> Corrosion test

For the test pieces of Example 1 and Comparative Example 1, the degree of corrosion was confirmed by immersion in 80% sulfuric acid for 4 hours. These sulfuric acid conditions simulate the sulfuric acid environment used for casting metal thin films.

Looking at FIGS. 10 and 11 showing the specimens before and after immersion in sulfuric acid, it can be seen that in Comparative Example 1, the microstructure is non-uniform and severe corrosion occurs, whereas in the case of Example 1, the microstructure compared to Comparative Example 1 It can be confirmed that this is uniform and more resistant to corrosion.

100 rotating cathode drum
110 titanium layer
111 Titanium base material layer
111a titanium base material
111b weld
112 DED titanium layer
120 metal layers
200 positive electrode
300 electrolyte
1000 thin film manufacturing equipment

Claims (9)

In the cylindrical rotating cathode drum having an inner space,
The rotating cathode drum has a titanium layer stacked on a metal layer,
The titanium layer is a rotating cathode drum for thin film production, characterized in that it comprises a DED titanium layer formed by laminating titanium powder or titanium alloy powder on the outer surface in a direct energy deposition method.
According to claim 1,
The titanium layer is a rotating cathode drum for thin film production, characterized in that made of the DED titanium layer.
According to claim 1,
The titanium layer is a rotating cathode drum for thin film production, characterized in that it includes a titanium base material layer including a welding part under the DED titanium layer.
According to claim 1,
A rotating cathode drum for thin film production, characterized in that the average size of the grains of the DED titanium layer is 1 ㎛ to 100 ㎛.
According to claim 1,
The metal layer is a rotating cathode drum for thin film production, characterized in that it comprises at least one material selected from the group consisting of titanium, copper, stainless steel, carbon steel and aluminum.
According to claim 1,
The iron content of the DED titanium layer is 0.3 wt% or less, and the hydrogen content is 0.015 wt% or less.
A method for manufacturing a rotating cathode drum for thin film manufacturing comprising the step of forming a titanium layer on a metal layer,
The forming of the titanium layer on the metal layer may include laminating a titanium powder or a titanium alloy powder in a direct energy deposition method;
A method for manufacturing a rotating cathode drum for thin film production, comprising:
8. The method of claim 7,
The step of forming a titanium layer on the metal layer,
Before the step of laminating the titanium powder or titanium alloy powder in a direct energy deposition method,
forming a titanium layer including a welding part by welding on the metal layer;
A method for manufacturing a rotating cathode drum for thin film production, characterized in that it further comprises a.
The rotating cathode drum of claim 1;
positive electrode; and
electrolyte;
A thin film manufacturing apparatus comprising a.

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