JP2011214018A - Cooling drum and vacuum treatment apparatus including the same, and surface treatment method - Google Patents

Abstract

A cooling drum, a vacuum processing apparatus including the same, and a surface processing method are provided that suppress wrinkles due to heat when the surface of the metal foil or alloy foil is subjected to surface treatment under vacuum.
A copper oxide layer 20a is used in a vacuum processing apparatus 1 that performs surface treatment on a metal foil or alloy foil 10 that is continuously unwound and wound up under vacuum, with a covering ratio of at least 40% on the surface. Is a cooling drum 20 that cools in close contact with a metal foil or alloy foil.
[Selection] Figure 2

Description

  The present invention relates to a cooling drum used when a metal foil or alloy foil is subjected to surface treatment such as vapor deposition or sputtering in a vacuum.

2. Description of the Related Art Conventionally, a vacuum processing apparatus is known in which a surface-treated material such as a film is continuously unwound under vacuum, and wound after being subjected to surface treatment such as vapor deposition on the surface (Patent Document 1). Moreover, in order to prevent thermal deformation of the film at the time of vapor deposition, the film is vapor-deposited while being in close contact with a cooling roll.
Such a winding-type vacuum apparatus includes a vapor deposition apparatus or a sputtering apparatus, an unwinding section and a winding section for a surface-treated material, a cooling drum, and a vacuum chamber for housing them. Further, a pre-treatment device such as glow discharge and ion gun, an intermediate roll, etc. are included as necessary.
Many of the rolls in these vacuum processing apparatuses are made of stainless steel or aluminum, and the surface thereof is often subjected to Cr plating or Ni plating for improving wear resistance. Further, as the surface treatment material, a resin film such as PET resin or polyimide resin is often used.

By the way, when the resin film is unwound and surface treatment such as vapor deposition or sputtering is performed, there is a problem that wrinkles enter the film or foil due to heat generated during the surface treatment.
In addition, when surface treatment such as sputtering is performed on the metal foil under vacuum instead of the resin film, wrinkles tend to occur more easily than the resin film. In particular, when the metal foil is thinner than 20 μm, the rigidity against bending becomes low, so that wrinkles are likely to occur due to thermal expansion during the surface treatment. And once wrinkles are generated, the wrinkled portions do not come into contact with the cooling roll, so the amount of heat removal decreases, the temperature rises further, the thermal expansion becomes significant, and the wrinkles are finally subjected to plastic deformation. .
For this reason, a technique is disclosed in which the thermal expansion coefficient of the surface material of the cooling drum is close to the thermal expansion coefficient of the metal foil that is the surface treatment material (Patent Document 2).

Japanese Patent No. 3795518 JP 2008-248296 A

However, although it is effective to match the thermal expansion coefficient of the surface material of the cooling drum to that of the metal foil, a temperature difference occurs between the cooling roll and the metal foil, and wrinkles are completely eliminated. It is difficult to prevent.
That is, the present invention has been made to solve the above problems, and when performing surface treatment on a metal foil or alloy foil under vacuum, a cooling drum that suppresses wrinkles due to heat, and a vacuum processing apparatus including the same, An object of the present invention is to provide a surface treatment method.

As a result of various studies, the present inventors have reduced the friction coefficient of the cooling drum by providing a copper oxide layer on the surface of the cooling drum, and the wrinkles of the metal foil are removed by sliding the metal foil in the axial direction. I found out.
In order to achieve the above object, the cooling drum of the present invention is used in a vacuum processing apparatus for surface-treating a metal foil or an alloy foil that is continuously unwound and wound under a vacuum, and has a surface of at least 40%. It is a cooling drum in which a copper oxide layer is formed with the above-mentioned covering ratio, and is cooled in close contact with the metal foil or alloy foil.

Preferably, the coverage of the copper oxide layer is 60% or more, and the non-formation region of the copper oxide layer is not continuous in the circumferential direction of the cooling drum.
The thickness of the copper oxide layer is preferably 0.1 μm or more and 100 μm or less.

  The vacuum processing apparatus of the present invention includes the cooling drum, an unwinding unit for unwinding the metal foil or the alloy foil, a winding unit for unwinding the metal foil or the alloy foil unwound from the unwinding unit, A surface treatment unit that performs surface treatment on the metal foil or alloy foil that faces the cooling drum and is in close contact with the cooling drum, and a vacuum chamber that accommodates the surface treatment unit, and the cooling drum includes the unwinding unit and the winding unit. It is arrange | positioned between the taking parts.

  In the surface treatment method of the present invention, the metal foil or the alloy foil is surface-treated in a vacuum using the vacuum treatment apparatus.

  According to the present invention, when a surface treatment is performed on a metal foil or an alloy foil under vacuum, wrinkles due to heat can be suppressed.

It is a figure which shows the structure of the vacuum processing apparatus provided with the cooling drum which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the cooling drum which concerns on 1st Embodiment. It is sectional drawing which shows the structure of the cooling drum which concerns on 2nd Embodiment. It is a figure which shows the state which the non-formation area | region of the copper oxide layer continued to the perimeter of the circumferential direction of a cooling drum.

Hereinafter, with reference to FIG. 1, the structure of the vacuum processing apparatus 1 provided with the cooling drum which concerns on the 1st Embodiment of this invention is demonstrated.
In FIG. 1, a vacuum processing apparatus 1 includes an unwinding unit 2 for unwinding a metal foil 10 that is a surface treatment material, a winding unit 4 for unwinding the metal foil 10 unwound from the unwinding unit 2, and cooling. A drum 20, a sputtering apparatus (surface treatment unit) 6 that performs surface treatment on the metal foil 10 that faces the cooling drum 20 and is in close contact with the cooling drum, and a vacuum chamber (vacuum chamber) 100 that accommodates these are provided. . The cooling drum 20 is disposed between the unwinding unit 2 and the winding unit 4, and the metal foil 10 unwound from the unwinding unit 2 passes through the foil while being in close contact with the cooling drum 20. ing. In this embodiment, a plurality of intermediate rolls are arranged between the unwinding unit 2 and the cooling drum 20 and between the winding unit 4 and the cooling drum 20.

Further, in this embodiment, the sputtering apparatus 6 includes a Ni sputtering apparatus 6a and a Cr sputtering apparatus 6b, respectively, and each sputtering apparatus is a DC magnetron sputtering apparatus. The ion gun 8 is also disposed in the vacuum chamber 100 so as to face the cooling drum 20 so that the pretreatment of the metal foil 10 can be performed before sputtering.
The ion gun 8, the Ni sputtering apparatus 6a, and the Cr sputtering apparatus 6b are arranged around the cooling drum 20 along the circumferential direction, and process the metal foil 10 in the order of pretreatment by the ion gun 8, Ni sputtering, and Cr sputtering. It is like that.

Next, the configuration of the cooling drum 20 which is a characteristic part of the present invention will be described with reference to FIG.
The cooling drum 20 has a cylindrical shape and is rotatable around an axis P (see FIG. 1). A copper oxide layer 20 a is formed on the surface of the cooling drum 20.

Normally, when the friction coefficient of the cooling drum is lowered, slip occurs between the cooling drum and the metal foil, scratching occurs on the foil, or the foil feeding speed is unstable when the foil feeding speed is controlled by the cooling drum. This is not preferable because the surface treatment becomes non-uniform.
However, as a result of investigations by the present inventors, in a vacuum, the friction coefficient is not reduced by the entrainment of air as in the atmosphere, so that the substantial frictional force is higher than in the air. Therefore, even if the friction coefficient of the cooling drum is lowered, slip hardly occurs. On the other hand, if the friction coefficient of the cooling drum is reduced, the wrinkles of the metal foil generated on the cooling drum due to the heat of the surface treatment (evaporation, sputtering, etc.) are generated. It was found that this can be eliminated by sliding between the metal foil and the cooling drum surface.
The present inventors have found that the copper oxide layer 20a is suitable as a material for reducing the coefficient of friction with the metal foil. Examples of the composition of the copper oxide layer 20a include cuprous oxide (Cu ₂ O) or cupric oxide (CuO). Cupric oxide is particularly preferable.

As a material of the cooling drum 20, copper, aluminum, a copper alloy, or an aluminum alloy with good thermal conductivity can be preferably used. The copper oxide layer 20a can be formed by, for example, performing copper plating on the surface of the cooling drum 20 and oxidizing it. In the oxidation, a method of heating in the atmosphere, a method of chemically oxidizing using a chemical solution, or the like can be used. At this time, it is desirable to oxidize so that the ratio of cupric oxide becomes high. For example, when performing atmospheric oxidation, the ratio of cupric oxide can be increased by oxidizing at a high temperature of at least 400 ° C.
It is also possible to form a copper oxide layer 20a on the surface of the cooling drum 20 by magnetron sputtering deposition using a copper oxide target. The magnetron sputter deposition method has an advantage that the copper oxide layer 20a can be easily formed on the surface of the cooling drum and the oxide composition is easily made of cupric oxide.
In order to improve the adhesion between the copper oxide layer 20a and the cooling drum surface, the cooling drum surface before forming the copper oxide layer 20a is preferably subjected to pretreatment such as glow discharge or ion gun. However, as in the case where the cooling drum (at least the surface layer portion thereof) is made of a copper alloy and the copper oxide layer is directly formed on the surface, the pretreatment can be omitted depending on the material of the cooling drum.

A chromium plating or nickel plating layer may be provided on the surface of the cooling drum, and the copper oxide layer 20a may be formed on the plating layer. When the cooling drum is made of copper, aluminum, or the like, the hardness is low and the drum is physically easily scratched. Therefore, the hardness can be improved by chromium plating or nickel plating to prevent the scratch.
Further, it is preferable that the surface roughness of the cooling drum is small because the contact area is increased and heat transfer is promoted. The surface roughness of the cooling drum is preferably 0.2 μm or less, more preferably 0.05 μm or less in terms of arithmetic average roughness Ra after forming the copper oxide layer 20a.

  The thickness of the copper oxide layer 20a is preferably 0.1 μm or more and 100 μm or less. When the thickness of the copper oxide layer 20a is less than 0.1 μm, the copper oxide layer 20a is worn out and disappears when slipping or the like occurs when the foil is passed in the air. Since it is necessary to form, it is not preferable. On the other hand, if the thickness of the copper oxide layer 20a exceeds 100 μm, it may be disadvantageous for heat transfer and may be uneconomical. In addition, troubles that the oxide film is detached easily occur.

By the way, by providing the copper oxide layer 20a on the surface of the cooling drum 20 as described above, the friction coefficient of the cooling drum can be reduced, and the wrinkles of the metal foil can be eliminated by sliding with the surface of the cooling drum. However, if the coefficient of friction of the cooling drum is too small, slippage between the metal foil and the surface of the cooling drum may become too good even in vacuum, resulting in problems.
Therefore, as shown in FIG. 2, it is preferable to form a copper oxide layer 20a on a part of the surface of the cooling drum 20 to adjust the friction coefficient. In this case, the portion where the copper oxide layer 20a is not formed shows the friction coefficient of the material of the cooling drum 20, and the friction coefficient becomes larger than the copper oxide layer 20a in this portion.

Furthermore, the coverage of the copper oxide layer 20a on the entire surface of the cooling drum 20 is set to 40% or more. It is preferable that the coverage is 60% or more and that the non-formation region of the copper oxide layer is not continuous in the circumferential direction d of the cooling drum 20. If the coverage of the copper oxide layer 20a with respect to the entire surface of the cooling drum 20 is less than 40%, it becomes difficult to slip at the portion of the substrate having a high friction coefficient, and therefore, the slip between the metal foil and the surface of the cooling drum is insufficient. There is a case.
For example, in the cooling drum 20 of FIG. 2, the copper oxide layer 20 a is coated in a stripe shape parallel to the axial direction L. In this case, as viewed from the circumferential direction d, the copper oxide layer 20a is formed in a part d1 in the circumferential direction, and a non-formation region of the copper oxide layer 20a exists in a part d2 in the circumferential direction. The region is not continuous over the entire circumference in the circumferential direction d.
Wrinkles of the metal foil generated on the surface of the cooling drum 20 are removed by sliding the metal foil in the axial direction L. Therefore, if the metal foil is in contact with the copper oxide layer 21a at a part d1 in the circumferential direction, the metal foil can slide along the axial direction L without being caught in this part d1, and the wrinkles of the metal foil are removed. be able to.
On the other hand, when the non-formation region of the copper oxide layer 20a is continuous over the entire circumference in the circumferential direction d, the metal foil is caught in the non-formation region and is difficult to slide in the axial direction L, and wrinkles tend not to be removed. it is conceivable that. In this respect, it is not preferable to cover the surface of the cooling drum with the copper oxide layer in a stripe shape parallel to the circumferential direction d as compared with the case of FIG.

As a method of forming a copper oxide layer on a part of the surface of the cooling drum, a masking tape is applied to the surface of the cooling drum or a pattern of a non-formed part is formed with oil, and then a copper oxide layer is formed. A method of performing plating or sputtering is simple.
Depending on the type of metal foil, surface roughness, metal foil tension, winding angle of the metal foil around the cooling drum, etc., even if a copper oxide layer is formed on the entire surface of the cooling drum, there is a problem of slip. In this case, it is preferable to form a copper oxide layer on the entire surface of the cooling drum.
Further, the surface treatment material to which the cooling drum is applied includes not only metal foil but also alloy foil.

Next, the configuration of the cooling drum 21 according to the second embodiment of the present invention will be described with reference to FIG. The cooling drum 21 can be attached to the vacuum processing apparatus 1 instead of the cooling drum 20.
In the cooling drum 21 of FIG. 3, a copper oxide layer 21a is formed in an island shape on the surface. In this case, as viewed from the circumferential direction d, a non-formation region of the copper oxide layer 21a exists in a part d3 in the circumferential direction, but this non-formation region is not continuous over the entire circumference in the circumferential direction d. That is, if the metal foil is in contact with the copper oxide layer 21a at a point, the metal foil can slide without being caught in the axial direction L while sequentially contacting the plurality of islands along the axial direction L. Wrinkles on the metal foil can be removed.

  FIG. 4 shows an example in which the non-formation region Lx of the copper oxide layer 21a is continuous over the entire circumference in the circumferential direction d in the cooling drum 21 of FIG. In this case, even if the metal foil tries to move in the axial direction L, the metal foil is caught in the non-formation region Lx and is difficult to slide in the axial direction L, so that wrinkles tend not to be removed.

EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these.
<Vacuum processing equipment>
As shown in FIG. 1, an unwinding unit 2, a winding unit 4, a cooling drum 20, a DC magnetron sputtering device (surface treatment unit) 6, an ion gun 8, an intermediate roll, and a vacuum chamber that accommodates them. (Vacuum chamber) 100 was prepared. 80 mass% Ni-20 mass% Cr was used as the target of the sputtering apparatus 6 (the target size was 130 mm in length, 460 mm in width, and the number of targets was 1).
Further, as the cooling drum 20, those in which a copper oxide layer is formed by various coating methods and coating patterns shown in Table 1 (each of FIGS. 2, 3, 4, or the entire drum surface) are used. It was. In Table 1, the coating method “sputtering” is a magnetron sputtering deposition method using copper oxide as a target, and “atmospheric oxidation after electroplating” is copper plating on the cooling drum surface, It was oxidized at 450 ° C. for 10 minutes. “Atmospheric oxidation” is the oxidation of the copper alloy on the surface of the cooling drum that is held at 450 ° C. for 10 minutes in the air.
A rolled copper foil coil having a width of 300 mm and a thickness of 8 μm was attached to the unwinding part 2 as a metal foil as a surface treatment material. This rolled copper foil was a rolled copper foil and was not subjected to surface treatment.

<Surface treatment (sputtering) conditions>
Using the sputtering apparatus 6, the sputtering output and the foil passing speed were adjusted so that a Ni-Cr film was formed to a thickness of 20 nm on the copper foil in one pass. The degree of vacuum of the vacuum processing apparatus 1 during sputtering was 0.665 Pa (5 × 10 ⁻³ Torr), the temperature of the cooling drum was 25 ° C., and the tension was 50 MPa or 10 MPa.

<Evaluation of wrinkles>
After sputtering, the copper foil was taken out of the apparatus, visually checked for wrinkles on the copper foil, and evaluated according to the following criteria. If the evaluation is △ or ○, there is no practical problem ○: No wrinkle △: Slightly wrinkled ×: Folded wrinkle <Evaluation of slip (slip)>
After sputtering, the copper foil was taken out of the apparatus, visually checked for the presence or absence of slip scratches on the copper foil, and evaluated according to the following criteria. If the evaluation is A or B, there is no practical problem.
A: There is no slip scratch. O: There is a slip scratch with a length of 0.1 mm or less. X: There is a slip scratch with a length exceeding 0.1 mm. The obtained results are shown in Table 1.

As is clear from Table 1, in the case of Experimental Examples 1 to 10 in which the copper oxide layer was formed on the surface of the cooling drum with a coverage of 40% or more, the foil feeding tension was appropriately adjusted, so that wrinkles and slips were observed. Did not occur.
In the case of Example 8, the coverage of the copper oxide layer was smaller than that of the other examples, so that it was slightly slippery in the axial direction of the cooling drum, and slight heat wrinkles were generated on the copper foil. However, there is no problem in practical use.
In the case of Example 9, since the thickness of the copper oxide layer is as thick as 200 μm, the copper oxide may be partially peeled off, the heat transfer of that portion is deteriorated, and the copper foil is slightly wrinkled. occured. However, there is no problem in practical use.
Furthermore, in the case of Example 10, the copper oxide is formed in an island shape, and the non-formation region of the copper oxide layer is continuous over the entire circumference in the circumferential direction of the cooling drum. For this reason, the copper foil was slightly difficult to slide in the axial direction of the cooling drum, and the copper foil was slightly wrinkled. However, there is no problem in practical use.

On the other hand, in the case of Comparative Example 1 in which the copper oxide layer was not formed on the surface of the cooling drum, wrinkles were generated on the copper foil, the sliding between the copper foil and the cooling drum was bad, and wrinkles were generated.
In Comparative Examples 2 and 3 where the coverage of the copper oxide layer was less than 40%, the sliding between the copper foil and the cooling drum was poor, and wrinkles were generated.
In the case of Comparative Example 4 in which the foil thread tension was lowered, the copper foil and the cooling drum slipped too much and slip scratches were generated.

DESCRIPTION OF SYMBOLS 1 Vacuum processing apparatus 2 Unwinding part 4 Winding part 6 Sputtering apparatus (surface treatment part)
10 Metal foil 20, 21 Cooling drum 20a, 21a Copper oxide layer 100 Vacuum chamber (vacuum chamber)

Claims (5)

Used in vacuum processing equipment for surface treatment of metal foil or alloy foil that is continuously unwound and wound under vacuum,
A cooling drum in which a copper oxide layer is formed on the surface with a coverage of at least 40% and is cooled in close contact with the metal foil or alloy foil. 2. The cooling drum according to claim 1, wherein a coverage of the copper oxide layer is 60% or more, and a non-formation region of the copper oxide layer is not continuous in a circumferential direction of the cooling drum. The cooling drum according to claim 1 or 2, wherein the thickness of the copper oxide layer is 0.1 µm or more and 100 µm or less. The cooling drum in any one of Claims 1-3, the unwinding part which unwinds the said metal foil or alloy foil, and the winding-up part which winds up the said metal foil or alloy foil unwound from the said unwinding part And a surface treatment unit that performs surface treatment on the metal foil or alloy foil that faces the cooling drum and is in close contact with the cooling drum, and a vacuum chamber that accommodates these.
The said cooling drum is a vacuum processing apparatus arrange | positioned between the said unwinding part and the said winding-up part. The surface treatment method which uses the vacuum processing apparatus of Claim 4, and surface-treats the said metal foil or alloy foil in a vacuum.

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