Vacuum processing apparatus and vacuum processing method

Abstract

When the sheet-like substrate Sw is fed from the dispensing shaft 3a and wound onto the winding shaft 3b, a vacuum treatment involving heat input is applied to the substrate portion Swp wound onto the can roller 2. This process suppresses the formation of wrinkles in the substrate while ensuring good adhesion to the can roller 2. [Solution] The system comprises a restricting plate 6 that restricts the processing range by an opening 61 that locally faces the substrate portion, and a power supply that applies voltage between the plate and the can roller. The leading edge 62 of the opening located on the upstream side in the substrate transport direction is configured such that the processing range in the width direction of the substrate portion continuously increases from the starting point in the center of the substrate width direction toward both ends in the width direction.

Description

Technical Field

[0001] The present invention relates to a vacuum processing apparatus and a vacuum processing method for performing a predetermined vacuum treatment on the outer surface of a base material portion wound around a can roller in a vacuum chamber in a vacuum atmosphere, while a sheet-shaped base material is unwound from an unwinding shaft and the unwound sheet-shaped base material is wound up by a winding shaft.

Background Art

[0002] As this type of vacuum processing apparatus, a vacuum vapor deposition apparatus is known, for example, in Patent Document 1, in which a vapor deposition source is provided facing a can roller, and a metal film or the like is formed on one surface of a sheet-shaped base material such as a resin film by a vacuum vapor deposition method. In this apparatus, latent heat and radiant heat are applied from the vapor deposition source to the base material portion during film formation, so heat is removed from the sheet-shaped base material by cooling the outer peripheral surface of the can roller in contact with the base material portion. At this time, in order to enhance the adhesion to the can roller and increase the heat removal amount (cooling performance) of the sheet-shaped base material, an auxiliary roller in contact with the metal film formed on one surface of the sheet-shaped base material is disposed between the can roller and the winding shaft, and a DC voltage is applied between the can roller and the auxiliary roller from a power supply. As a result, when the metal film is formed on the base material portion wound around the can roller, the can roller and the auxiliary roller are electrically connected via the metal film, whereby an electrostatic adsorption force is generated, the base material portion is adsorbed to the outer peripheral surface of the can roller, and consequently the contact thermal conductivity between the can roller and the sheet-shaped base material can be improved.

[0003] In recent years, relatively thin and wide sheet-like substrates have come into use for vacuum processing. On the other hand, when depositing a metal film onto a sheet-like substrate, an increase in the deposition rate is increasingly required to improve productivity, and an increase in heat input to the substrate due to latent heat and radiant heat is expected. In addition, when the sheet-like substrate is relatively thin and wide, the buckling stress corresponding to the load in the width direction tends to increase with respect to buckling, which will be discussed later. When heat is applied to the sheet-like substrate, thermal expansion (linear expansion) occurs, and an increase in the amount of linear expansion is a concern due to the increase in heat input and the widening of the substrate. Furthermore, when thermal expansion occurs while the substrate is constrained by electrostatic adsorption to the outer surface of the can roller, compressive stress acts on the substrate around the constrained area. If this stress exceeds a certain level due to the increase in the amount of linear expansion, buckling occurs, causing localized wrinkles in the sheet-like substrate. Such wrinkles lead to product defects and must be suppressed as much as possible. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 3795518 [Overview of the project] [Problems that the invention aims to solve]

[0005] In view of the above, the object of the present invention is to provide a vacuum processing apparatus and a vacuum processing method that can suppress as much as possible the occurrence of wrinkles in a sheet-like substrate when a predetermined vacuum processing accompanied by heat input is performed while the substrate portion is adhered to the outer surface of a can roller with good adhesion. [Means for solving the problem]

[0006] To solve the above problems, the vacuum processing apparatus of the first invention is characterized in that, while a sheet-like substrate is fed from a feeding shaft and the fed sheet-like substrate is wound on a winding shaft, a predetermined vacuum treatment is applied to the outer surface of the substrate portion wound on a can roller in a vacuum chamber with a vacuum atmosphere, and a regulating plate is positioned radially outside the can roller that the substrate portion is in contact with and restricts the processing range by an opening that locally faces the substrate portion, and a power supply is provided to apply a voltage between the plate and the can roller, and when the outer surface of the sheet-like substrate and the can roller are electrically connected in conjunction with the vacuum treatment, the substrate portion is electrostatically attracted to the outer surface of the can roller, and the leading edge of the opening located on the upstream side in the conveying direction of the sheet-like substrate is configured such that the processing range in the width direction of the substrate portion continuously increases from the starting point in the width direction of the sheet-like substrate toward both ends in the width direction, or from the starting point in the width direction of one end toward the other end in the width direction. Furthermore, the vacuum processing method of the second invention is characterized in that, while a sheet-like substrate is fed from a feeding shaft and the fed sheet-like substrate is wound on a winding shaft, a predetermined vacuum processing is applied to the outer surface of the substrate portion wound on a can roller in a vacuum chamber with a vacuum atmosphere, the vacuum processing is performed while restricting the vacuum processing range with an opening positioned radially outside the can roller that the substrate portion is in contact with and locally facing the substrate portion, a voltage is applied between the can roller and the sheet-like substrate, and as the vacuum processing occurs the outer surface of the sheet-like substrate and the can roller are electrically connected, the substrate portion is electrostatically attracted to the outer surface of the can roller, and the processing area in the width direction of the sheet-like substrate is continuously increased from the starting point in the width direction of the sheet-like substrate toward both ends in the width direction, or from the starting point in the width direction of one end toward the other end in the width direction, by the leading edge of the opening located on the upstream side in the transport direction of the sheet-like substrate.

[0007] As described above, when the base material wrapped around the outer surface of the can roller passes the leading edge of the opening in the regulating plate, vacuum processing of the base material begins. As a result of this vacuum processing, the base material is electrostatically attracted to the outer surface of the can roller, while latent heat and radiant heat begin to be applied to the processing area of ​​the base material through the opening in the regulating plate. At this time, by continuously increasing the processing area from the center or one end in the width direction using the shape of the leading edge of the regulating plate, and by matching the direction in which the area receiving heat to the base material expands with the direction of thermal expansion, it is possible to suppress as much as possible the localized wrinkling of the sheet-like base material caused by excessive compressive force.

[0008] In the present invention, a configuration can be adopted in which the trailing edge of the opening located downstream in the conveying direction of the sheet-like substrate has the same shape as the leading edge. This is advantageous because, for example, when a vapor deposition source is provided opposite a can roller and a metal film or the like is deposited on one side of the sheet-like substrate, the uniformity of the film thickness in the width direction of the sheet-like substrate can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic cross-sectional view illustrating the vacuum deposition apparatus of this embodiment. [Figure 2] (a) is a diagram illustrating the film deposition process through the opening of the regulating plate onto the substrate portion, (b) is a cross-sectional view along the line IIb-IIb in Figure 2(a), (c) is a cross-sectional view along the line IIc-IIc in Figure 2(a), and (d) is a cross-sectional view along the line IId-IId in Figure 2(a). [Figure 3] (a) to (e) are plan views of modified versions of the control panel. [Figure 4] (a) is a diagram illustrating the film deposition process on the substrate portion through the opening of the restricting plate, using a restricting plate equivalent to a conventional example; (b) is a cross-sectional view along the line IVb-IVb in Figure 2(a); (c) is a cross-sectional view along the line IVc-IVc in Figure 2(a); and (d) is a cross-sectional view along the line IVd-IVd in Figure 2(a). [Modes for carrying out the invention]

[0010] Hereinafter, with reference to the drawings, embodiments of the vacuum processing apparatus and vacuum processing method of the present invention will be described using a roll-up type vacuum deposition apparatus DM as an example, which deposits a metal film such as an aluminum film or a copper film continuously onto one side of a sheet-like substrate Sw by vacuum deposition. In the following, the two orthogonal directions will be the X-axis direction and the Y-axis direction, which is the width direction of the substrate, and directions such as up and down will be based on Figure 1, which shows the installation position of the vacuum deposition apparatus DM. For example, a resin material can be used as the sheet-like substrate Sw.

[0011] Referring to Figure 1, the vacuum deposition apparatus DM includes a vacuum chamber 1 to which a vacuum pump (not shown) is connected, enabling the formation of a vacuum atmosphere. Inside the vacuum chamber 1, a can roller 2 is arranged, on which a sheet-like substrate Sw portion (hereinafter referred to as the "substrate portion Swp") is wound and which is rotationally driven by a motor M1. The vacuum chamber 1 is provided with a separator plate 11, separating it into two upper and lower chambers: a transport chamber 1a where approximately the upper half of the can roller 2 is located, and a film deposition chamber 1b where approximately the lower half of the can roller 2 is located (atmosphere separation). The transport chamber 1a is provided with first and second double feed / wind rollers 3a and 3b, which are rotationally driven in forward and reverse directions by motors M2 and M3, and a plurality of guide rollers 4 located between the double feed / wind rollers 3a and 3b to guide the sheet-like substrate Sw to the can roller 2. In this embodiment, the double feed / wind rollers 3a and 3b serve as the feed shaft and winding shaft of this embodiment. Then, with the sheet-like substrate Sw wrapped around the outer surface of the can roller 2 at a predetermined wrapping angle, the motors M1 to M3 are driven to rotate, causing the sheet-like substrate Sw to be transported (traveled) from one of the first and second feed / wind-up rollers 3a and 3b to the other. In the following, the upstream and downstream directions of transport are based on the state in which the can roller 2 is rotated counterclockwise and the sheet-like substrate Sw is transported.

[0012] The can roller 2 is made of metal and comprises a shaft 21 extending in the Y-axis direction, an inner cylinder 22 fitted onto the shaft 21, and an outer cylinder 23 that surrounds the outer surface of the inner cylinder 22 with a gap and around which the base material portion Swp is wrapped. Both ends of the inner cylinder 22 and the outer cylinder 23 in the Y-axis direction are closed by cover bodies (not shown), and the shaft 21 is pivotally supported on the wall of the vacuum chamber 1 via bearings (not shown). The space 24a inside the shaft 21 and the space 24b between the outer surface of the inner cylinder 22 and the inner surface of the outer cylinder 23 constitute a refrigerant circulation path, and the outer surface of the outer cylinder 23 can be cooled by circulating a refrigerant such as cooling water from the chiller unit 25. The cooling temperature of the outer cylinder 23 at this time is set to, for example, in the range of -50°C to +100°C, and the base material portion Swp is cooled by contact heat conduction with the outer surface of the cooled outer cylinder 23.

[0013] An insulating layer 23a, such as alumina, is formed on the outer surface of the outer cylinder 23. The can roller 2 and the guide roller 4a, which comes into contact with a metal film Mf deposited on one side of the sheet-like substrate Sw, are electrically connected, and a predetermined DC voltage can be applied by the DC power supply 26. The applied voltage is set, for example, in the range of -3kV to +3kV, taking into consideration the film deposition rate, the transport speed of the sheet-like substrate Sw, the material of the substrate Sw, etc. Note that if the sheet-like substrate Sw itself acts as an insulating layer, the insulating layer 23a can be omitted. Also, the heat transfer coefficient h(W / m) between the sheet-like substrate Sw and the can roller 2 with which it is in close contact is... 3 ·k) is the amount of heat input from the deposition source described later, Q (W / m 2 If the temperature of the can roller 2 is Tb (°C) and the substrate temperature is Tf (°C), then h can be calculated using the formula h = Q / (Tf-Tb). Therefore, by setting the applied voltage according to the required heat transfer coefficient, heat can be effectively removed from the substrate portion Swp and the temperature of the sheet-like substrate Sw can be maintained within a predetermined temperature range.

[0014] In the deposition chamber 1b, a deposition source 5 is positioned directly below the can roller 2. The deposition source 5 comprises a crucible 51 for containing a solid deposition material Mv, and a heating means 52, such as a sheath heater, provided inside the crucible 51 for heating the deposition material Mv. The deposition material Mv is appropriately selected according to the thin film to be deposited on the sheet-like substrate Sw, and for example, aluminum or copper is used. The deposition chamber 1b is also provided with a regulating plate 6 positioned radially outward from the can roller 2 in contact with the substrate portion Swp (in this embodiment, positioned directly below the can roller 2), which restricts the vacuum processing range with a single opening 61 that locally faces the substrate portion Swp. The regulating plate 6 is made of, for example, alumina or stainless steel, and has a width that covers the can roller 2 along the entire length in the Y-axis direction, and functions as an anti-deposition plate. The following describes the case in which a predetermined metal film is deposited on one side of the sheet-like substrate Sw through the opening 61 of the regulating plate 6 using the vacuum deposition apparatus DM described above.

[0015] Motors M1 to M3 are driven to feed out the sheet-like substrate Sw from the first feed / wind-up roller 3a at a predetermined speed, and the sheet-like substrate Sw is wound up by the second feed / wind-up roller 3b. Simultaneously, the chiller unit 25 circulates refrigerant through the refrigerant circulation passages 24a and 24b to cool the outer surface of the can roller 2 (outer cylinder 23) to a predetermined temperature. Then, the heating means 52 is activated in the vacuum chamber 1 under a vacuum atmosphere to vaporize the deposition material Mv in the crucible 51, and this vaporized deposition material Mv is released from the top opening of the crucible 51. As a result, a metal film Mf is deposited on the portion of the sheet-like substrate Sw that sequentially crosses the opening 61 of the regulating plate 6, i.e., the substrate portion Swp, beyond the opening 61 of the regulating plate 6 (i.e., in a state where only the substrate portion Swp facing the opening 61 as viewed from the deposition source 5 is the deposition area). During film deposition, a DC voltage is applied by the power supply 26 between the guide roller 4 that the metal film Mf contacts (hereinafter referred to as the "auxiliary roller 4a") and the can roller 2.

[0016] When the can roller 2 and the auxiliary roller 4a are electrically connected via the metal film Mf deposited on the substrate portion Swp, an electrostatic adsorption force is generated, and the substrate portion Swp is adsorbed onto the outer surface of the can roller 2. As a result, during film deposition, latent heat and radiant heat from the deposition source 5 are added to the substrate portion Swp, but the heat is dissipated from the sheet-like substrate Sw by contact heat conduction between the cooled can roller 2 and the substrate portion Swp, maintaining it within a predetermined temperature range. In other words, the sheet-like substrate Sw wrapped around the can roller 2 has contact heat conduction corresponding to the normal force due to its tension, and when the normal force due to the electrostatic adsorption force is added to this, the contact heat conduction is improved, and the sheet-like substrate Sw is maintained within a predetermined temperature range.

[0017] Here, as shown in Figure 4(a), if a regulating plate 60 with a roughly rectangular opening 60a is used (corresponding to the conventional example), when the substrate portion Swp crosses the leading edge 60b of the opening 60a, the entire length in the Y-axis direction becomes a film deposition area and the metal film Mf begins to be deposited (see Figure 4(b)). As the metal film Mf is formed, the substrate portion Swp is adsorbed onto the outer surface of the can roller 2. The thickness of the metal film Mf increases until it crosses the trailing edge 60b of the opening 60a (see Figures 4(c) and 4(d)). At this time, depending on the width and material of the sheet-like substrate Sw, compressive stress (arrow in Figure 4(c)) caused by thermal expansion while adsorbed to the can roller 2 (restrained state) may cause localized wrinkles Swr on the substrate portion Swp (this may also result in a loss of smoothness on the metal film surface). Therefore, it is necessary to suppress the occurrence of localized wrinkles Swr as much as possible.

[0018] In this embodiment, as shown in Figure 2, the opening 61 of the regulating plate 6 is configured to have the following contour. That is, the front edge 62 of the opening 61 located on the upstream side in the conveying direction is formed such that the processing range for the base material portion Swp continuously increases from the starting point 63 in the center of the Y-axis direction toward both ends in the Y-axis direction (in other words, it forms a V-shaped contour) as it moves toward the downstream side in the conveying direction (from left to right in Figure 2). The side edges 64 on both ends of the front edge 62 extend linearly in the X-axis direction and then continue toward the rear edge 65. In this case, the rear edge 65 is formed to have the same shape as the front edge 62.

[0019] As described above, when the substrate portion Swp crosses the leading edge 62, only the central part of the substrate portion Swp in the Y-axis direction becomes the film-forming area, and the metal film Mf begins to form (see Figure 2(b)). As the metal film Mf forms, the substrate portion Swp is adsorbed onto the outer surface of the can roller 2. Then, by the time it crosses the trailing edge 65 of the opening 61, the thickness of the metal film Mf increases along the entire length in the Y-axis direction (see Figure 2(c)), and once it crosses the trailing edge 65, it is formed with a similar thickness along the entire length in the Y-axis direction (see Figure 2(d)). In this way, when the substrate portion Swp is transported across the opening 61, by matching the direction in which the area of ​​heat input to the substrate portion Swp expands with the direction of thermal expansion, it is possible to suppress as much as possible the occurrence of localized wrinkles in the sheet-like substrate Sw due to excessive compressive force.

[0020] In other words, it is possible to suppress as much as possible the occurrence of wrinkles in the sheet-shaped base material Sw when performing a heat-input-involving vacuum deposition process while causing the base material portion Swp to be adsorbed to the outer peripheral surface of the can roller 2 with good adhesion. That is, the inflow of heat causes planar expansion of the sheet-shaped base material Sw based on the thermal expansion coefficient, and the expansion also occurs in the Y-axis direction (width direction). The inventors believe that with respect to such expansion, (unlike the conventional example described above in which the sheet-shaped base material is restrained across both ends in the width direction) when only the axially central portion is locally restrained and expanded, most of the local expansion acts as a compressive load (buckling load) on the remaining portion in the Y-axis direction other than the restrained portion. At this time, since only the normal reaction force resulting from tension is applied to the remaining portion, sliding in the Y-axis direction (viscous behavior exhibited by the friction between the sheet-shaped base material Sw and the outer peripheral surface of the can roller 2) is induced, and this sliding in the Y-axis direction secures the distance corresponding to the expansion accompanying the inflow of heat, whereby the buckling load applied to the sheet-shaped base material Sw is reduced, and as a result, the occurrence of wrinkles in the sheet-shaped base material Sw can be suppressed as much as possible.

[0021] While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention. In the above-described embodiments, a case where a film is formed by a vacuum deposition method is described as an example of the vacuum treatment, but there is no limitation to this as long as the vacuum treatment involves heat input to the sheet-shaped base material Sw while the base material portion is adsorbed to the outer peripheral surface of the can roller 2 with good adhesion. For example, the present invention can be widely applied to CVD treatments and etching treatments using plasma. In such a vacuum treatment, when plasma is generated on the radially outer side of the can roller that is in contact with the base material portion, electrons are charged on the sheet-shaped base material Sw. If the power supply 26 and the can roller 2 are electrically connected via these charged electrons, the base material portion Swp can be electrostatically adsorbed.

[0022] In the above-described embodiment, the front edge 62 of the opening 61 of the regulation plate 6 has a doglegged contour, and the sheet-like base material Sw is described by taking the example where the center in the width direction is set as the starting point 63. However, as long as the direction in which the heat input region to the base material portion Swp expands can match the direction of thermal elongation, the contour of the front edge 62 is not limited to this, and the position of the starting point 63 can also be set as appropriate. For example, as shown in Fig. 3(a), the front edge 62 of the opening 61 can be formed so as to connect the starting point 63 and the side edge 64 with a curve. Further, in the above-described embodiment, the case where the processing range continuously increases from the central starting point 63 is described as an example, but the present invention is not limited thereto. For example, as shown in Fig. 3(b) and Fig. 3(c), the processing range in the width direction of the base material portion may be continuously increased from the starting point 63 at one end in the width direction toward the other end in the width direction, and at this time, as shown in Fig. 3(d) and Fig. 3(e), the front edge 62 of the opening 61 may be a curved line. Furthermore, in the above-described embodiment, the case where the opening 61 of the regulation plate 6 is a single opening is described as an example, but the present invention is not limited thereto, and the present invention can also be applied to a configuration in which the opening of the regulation plate 6 is divided into a plurality of openings.

Description of Reference Numerals

[0023] DM...Vacuum deposition apparatus (vacuum processing apparatus), 1...Vacuum chamber, 2...Can roller, 24a, 24b...Refrigerant circulation passage (component of the cooling unit for cooling the outer peripheral surface of the can roller), 25...Chiller unit refrigerant circulation passage (component of the cooling unit for cooling the outer peripheral surface of the can roller), 26...DC power supply (power supply), 3a, 3b...Feed-out and take-up rollers (feed-out shaft, take-up shaft), 5...Deposition source, 6...Regulation plate, 61...Opening, 62...Front edge of the opening, 63...Starting point, 65...Rear edge of the opening, Sw...Sheet-like base material, Swp...Base material portion, Mf...Metal film.

Claims

1. A vacuum processing apparatus that feeds out a sheet-like substrate from a feeding shaft and, while winding the fed-out sheet-like substrate on a winding shaft, applies a predetermined vacuum treatment to the outer surface of the substrate portion wound on a can roller in a vacuum chamber under a vacuum atmosphere, In a system comprising a restricting plate positioned radially outside the can roller that contacts the substrate portion and restricting the processing area by an opening that locally faces the substrate portion, and a power supply that applies voltage between the can roller and the restricting plate, in which the outer surface of the sheet-like substrate and the can roller are electrically connected during vacuum processing, the substrate portion is electrostatically attracted to the outer surface of the can roller, A vacuum processing apparatus characterized in that the leading edge of an opening located on the upstream side in the conveying direction of a sheet-like substrate is configured such that the processing range in the width direction of the substrate portion continuously increases from the starting point in the width direction of the sheet-like substrate toward both ends in the width direction, or from the starting point at one end in the width direction toward the other end in the width direction.

2. The vacuum apparatus according to claim 1, characterized in that the trailing edge of the opening located downstream in the conveying direction of the sheet-like substrate is the same shape as the leading edge.

3. A vacuum processing method comprising: feeding out a sheet-like substrate from a feeding shaft; and while the fed-out sheet-like substrate is being wound onto a winding shaft, a predetermined vacuum treatment is applied to the outer surface of the substrate portion wound onto a can roller in a vacuum chamber under a vacuum atmosphere, In a system where a vacuum is applied while restricting the vacuum processing area by an opening positioned radially outside the can roller that contacts the substrate portion and locally facing the substrate portion, and when a voltage is applied between the can roller and the outer surface of the sheet-like substrate and the can roller are electrically connected as a result of the vacuum processing, the substrate portion is electrostatically attracted to the outer surface of the can roller, A vacuum processing method characterized by continuously increasing the processing area in the width direction of a sheet-like substrate from a starting point in the width direction of the sheet-like substrate toward both ends in the width direction, or from a starting point at one end in the width direction toward the other end in the width direction, by using the leading edge of an opening located on the upstream side in the transport direction of the sheet-like substrate.

Images