JP2805473B2 - Vacuum evaporation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention vapor-deposits a film such as a metal or metal oxide conductor on a vapor-deposited substrate while providing a non-deposited part by shielding a predetermined part with a masking tape. The present invention relates to a vacuum evaporation method using a tape mask method. [Background Art] Conventionally, a non-deposited portion is left on a vapor-deposited base material such as a plastic film or a glass sheet, that is, in a pattern,
Vacuum evaporation methods for forming a metal film such as Al, Zn, Au, Ag, or a metal oxide conductor film such as tin oxide, indium oxide, or a mixture thereof (ITO) have been widely performed.
As a result, various kinds of vapor-deposited products for decoration or electric use are manufactured. Examples of the vapor-deposited products having such a patterned vapor-deposited film include a capacitor film having a metal vapor-deposited film leaving a margin portion (non-vapor-deposited portion), an IT film, and the like.
A representative example is an electrode substrate on which a transparent electrode film such as O is formed. To form a patterned vapor deposition film on a vapor deposition substrate as described above, a method of forming a margin portion simultaneously with vapor deposition using a tape or an oil coating film as a masking material, or a uniform conductor film once on the substrate Is formed, and thereafter, a conductor film is selectively removed by a dry or wet etching method to form a margin portion. Among the various methods described above, the etching method requires a complicated etching process and has a disadvantage of increasing the manufacturing cost. Therefore, the etching method is not suitable unless a fine and complicated vapor deposition pattern is required. On the other hand, a masking method using an endless tape as a masking material is generally excellent in that a reliable margin portion can be formed in a masking portion, but the following methods (a) to (c) are used. Has problems. (B) Because the tape is repeatedly exposed to the vapor of the vapor, the vapor adheres and accumulates on the tape, and when the tape reaches a certain thickness, it peels off and falls off, causing the tape to sag. Or it may come off the tape groove of the guide roll in some cases. Therefore, the position of the non-evaporated portion of the obtained product is likely to be disturbed in the width direction. (B) In the case where the laminated deposits are peeled off and fall off, the laminated deposits are often scattered in fine particles from the tape, and these are entangled in the product to produce a defective product. (C) Therefore, even if it is an endless tape, it cannot be used for a long time, so that the length of a deposition base material that can be deposited is limited, and the tape needs to be replaced every operation. The oil mask method is a method in which a masking oil is applied to a portion corresponding to a non-deposition portion of a deposition base material immediately before the deposition to block and prevent deposition material vapor from adhering, and is an excellent method in principle. In addition, the expected effect cannot be sufficiently obtained depending on the oil used usually, and most of the existing semi-continuous vacuum evaporation apparatuses are based on a tape mask system, and the oil mask system cannot be applied to these. [Object of the Invention] An object of the present invention is to provide a tape mask type vacuum deposition method in which a non-deposition portion is formed in a pattern in a vacuum deposition method in which a problem associated with deposition of a deposit on a masking tape is improved. To provide. [Summary of the Invention] The present inventors have studied to achieve the above-mentioned object, and as a result, many of the oils used in the above-described oil mask method are not enough to form a sufficient margin portion in a vapor-deposited product. Even if it does not show enough masking effect,
By applying this to a masking tape, the above-mentioned (a) to (d) accompanying the deposition of the deposit on the masking tape
The present invention has been found to show a remarkable improvement effect on the problem (c). That is, the vacuum vapor deposition method of the present invention, when performing vacuum vapor deposition while masking a predetermined portion of the traveling vapor deposition base material with a masking tape, running the masking tape together with the vapor deposition substrate while making contact with the vapor deposition substrate, vacuum deposition Spraying or contact-transferring an oil for preventing deposition onto the surface of the masking tape which is exposed to a vapor of a deposition material at a position upstream of a deposition position in the room and upstream of a contact start position with the deposition base material. And perfluoroalkyl polyether is used as the deposition preventing oil. In particular, the perfluoroalkyl polyether discloses that the present inventors show excellent suitability as a masking oil to be applied to an oil mask method (Japanese Patent Publication No. 3-59981), and It has been found that the above problems (a) to (c) in the tape mask system can be almost completely solved by using the oil for preventing evaporation of the present invention by utilizing the excellent effect of preventing evaporation. I have. Example Hereinafter, a method for producing a metallized film for a capacitor as an example of a vacuum deposition method of the present invention will be specifically described with reference to the drawings. FIG. 1 is an internal front view of a semi-continuous manufacturing apparatus for a metallized film for a capacitor by tape mask type vacuum deposition, and FIG. 2 is a partial plan view of the metallized film for a capacitor obtained by the above method. Referring to FIG. 1, in a vacuum chamber A, a base film 2 unwound from a raw roll 1 made of PET (polyethylene terephthalate) or the like is taken up by a take-up roll 4 via a cooling can 3. Can be During this time, in the vacuum chamber B, evaporation of Al or the like is performed on the film 2 from the evaporation source 5 disposed below the cooling can 3. In the vacuum chamber B, a heat-resistant plastic such as polyimide or a heat-resistant material such as stainless steel is used.
A predetermined number of endless masking tapes 7 wound around a plurality of guide rolls 6 at intervals of, for example, 4 to 200 mm in the sheet thickness direction of the drawing,
And is transported at substantially the same speed as the substrate film. An oil coating device 8 is provided on the inner surface of the masking tape 7, that is, the surface exposed to the vapor such as Al.
(In this example, as shown in a perspective view in FIG. 3, the same number of slit-shaped openings 8a as the tape opened slightly wider (for example, about 1 to 2 mm) than the tape width at the same interval as the masking tape. ) Is applied from a pipe-shaped spray coating device). Since vapor such as Al from the evaporation source 5 is shielded by the masking tape 7, a predetermined width and a predetermined number of non-deposited portions (margin portions) are formed in the film 2 in a stripe shape. The metallized film 9 that has passed through the cooling can 3 has a partially planar shape as shown in FIG.
It comprises a vapor deposition section 10 and a margin section 11. The roll 4 on which this is wound is taken out and generally slit in the longitudinal direction at the center of each of the vapor deposition section and the margin section to form a narrow tape, which is wound and laminated to form a metallized film capacitor. . As shown in the above example, it is desirable to apply the deposition preventing oil before the masking tape 7 comes into contact with the base film 2 in the deposition section in the vacuum chamber. This is because an oil exhibiting a good vapor deposition preventing effect generally exhibits a slight vapor pressure at least in a vacuum vapor deposition atmosphere, so that the evaporation loss is suppressed and contamination of the vapor deposition atmosphere is suppressed, and the vapor deposition preventing effect is exhibited as effectively as possible. is there. Basically, in the conventional oil mask method, silicone oil, liquid paraffin, partially fluorinated silicone oil, or the like has been used as a masking oil as the evaporation preventing oil. However, in the present invention, perfluoroalkyl polyether is used as the oil for preventing deposition, and its specific excellent anti-deposition effect, vapor pressure characteristics, etc. are used. As the perfluoroalkyl polyether used in the present invention, preferably, both ends are stabilized with F—, CF ₃ —, CF ₃ O— or C ₂ F ₅ —, and the repeating units are represented by the following formulas (I) to (I). II
I) Formula _{(I) C 3 F 6 O} n Formula _{(II) C 3 F 6 O} n CF 2 O m Formula _{(III) C 2 F 4 O} n CF 2 O m ( where n, m are perfluoro (Indicating an average number of repeating units giving an average molecular weight of 1,000 to 15,000 as a whole of the alkyl polyether) is used alone or as a mixture of two or more of them. Note that n: m in the formulas (II) and (III) is, for example, about 30 to 4
The former is usually quite large, such as 0: 1. Repeating unit C ₃ F ₆ O _n is a straight chain structure C-C-C
-O _n, branched structure Any of these may be used. Examples of commercially available products include Demnum (trade name of formula (I) manufactured by Daikin Industries, Ltd.), Krytox (trade name of formula (I) manufactured by DuPont), Fomblin (Montezison Co., Ltd.) And a branched structure of formula (II) and formula (III)). Perfluoroalkyl polyether has an average molecular weight of 1000
115000, especially 1500-10000 are preferably used. Those having a molecular weight of less than 1000 have a high vapor pressure and a large evaporation loss during vacuum deposition. Further, the perfluoroalkyl polyether needs to have a viscosity suitable for coating, and if it exceeds 15,000, it is difficult to obtain a viscosity suitable for coating even when heated to a high temperature. In the above, the vacuum deposition method of the present invention has been described for typical embodiments. However, it can be easily understood that various modifications are possible within the scope of the present invention. For example, in addition to the above-mentioned PET, other than the above-described PET, polyimide, polycarbonate, polyacetate, polypropylene, a plastic film such as polyphenylene sulfide, a flexible film or sheet material such as paper are preferably used, and a tape. As long as deposition is possible while masking, a solid material such as a glass substrate can be used, and there is no particular restriction on the material. In addition to Al, Zn, Cu, Ni, Ag, Au and other metals or
In addition to such oxide conductor ITO, SiO, dielectric material such as SiO _2,
Various vapor-depositable dyes and pigments are also used, and among them, various conductor materials are preferably used. In addition, as the oil supply device, the spray coating device described above is preferably used,
A roll coating device is also suitably used. Also, for convenience, the tape may be brought into contact with a continuous foam, cloth, fiber bundle, or the like impregnated with oil, or the oil from the foam or the like may be temporarily supplied to the guide roll surface of the tape, and the tape may be transferred from the guide roll to the tape. Various methods are possible, for example, it can be applied to the surface. However, as described above, a method that can be applied before contacting the deposition base material in the vacuum deposition chamber is preferable.
The above-mentioned application mode is collectively referred to as spray application or contact transfer application. Further, as the vapor deposition method, in addition to vacuum vapor deposition in a narrow sense, various types of sputtering are also possible. Accordingly, the degree of vacuum can be selected from a wide range, for example, 10 ^-1 to 10 ^-6 Torr. Needless to say, the vapor deposition on the film or sheet substrate is not limited to one side, and may be performed on both sides. Hereinafter, the present invention will be described more specifically with reference to representative examples and comparative examples. Using a tape mask type semi-continuous vacuum evaporation system as shown in FIG. 1, polyethylene terephthalate (PE)
T) was vapor-deposited on one side of a film (thickness 4 μm, width 500 mm, length 10000 m). As the masking tape, five endless tapes each having a width of 5 mm and made of a polyimide film (125 μm in thickness) coated on both sides with a fluororesin were used at intervals of 120 mm. An oil-impregnated flannel material was used as the oil applying device 8 for the tape, and the tape was applied to the inner surface of the tape 6 of about 800 mm through the guide roll 6 before contacting the PET film. The vapor deposition was started after the degree of vacuum in the vacuum chamber A became about 10 ^-2 Torr and the degree of vacuum in the vacuum chamber B became about 10 ^-4 Torr. At a winding speed of the PET film of 220 m / min, the surface resistance of the Al vapor-deposited film was set to 2.0 ± 0.5Ω / □ (about 380 ° in thickness). The above operation was repeated while changing the type of oil. The results of observing the type of oil used and the state of adhesion of Al to the masking tape were as shown in Table 1. As can be seen from the above Table 1, by applying oil to the masking tape, it is possible to significantly suppress the state of adhesion of Al to the tape. Particularly, the effect when using perfluoroalkyl polyether is as follows. Very remarkable. Next, a PET film (thickness: 4 μm, width: 650 mm, length: 32) was applied using a tape mask type semi-continuous vacuum evaporation system as shown in FIG.
000m) on one side. As the masking tape 6, 21 endless tapes each having a width of 3 mm and made of a polyimide film (125 μm in thickness) coated on both sides with a fluororesin were used at intervals of 30 mm. As the oil application device 8,
Provided with a hollow pipe-shaped coating device with a built-in oil heater and a slit-shaped opening as an oil injection port and closed at both ends, masking perfluoroalkyl polyether (average molecular weight 4500) heated to 130 ° C It was made to spray on the inner surface of the tape. The degree of vacuum in vacuum chamber A is about
The deposition was started after the pressure in the vacuum chamber B reached 10 ⁻² Torr and the degree of vacuum in the vacuum chamber B reached about 10 ⁻⁴ Torr. The winding speed of the PET film was 250 m / min, and the surface resistance of the Al vapor-deposited film was 1.7 ± 0.5Ω / □ (about 400 ° in film thickness). In the case where oil is not applied to the tape, the upper limit of the length that can be deposited by the horizontal deflection of the tape and the fine particles scattered from the tape is 16000 m at the maximum, whereas in the present example where the perfluoroalkyl polyether is applied, it is 32000 m. No lateral deflection of the masking tape was observed even when the length was vapor-deposited, and no Al was attached to the tape. In addition, in the product taken out of the vapor deposition device, no disturbance in the width direction of the position of the non-vapor-deposited portion and no entrained Al fine particles were observed. [Effects of the Invention] As described above, when performing vacuum deposition while providing a non-deposition portion by a tape mask method, a surface of a masking tape exposed to a vapor of a deposition material is provided with an oil for preventing vapor deposition, particularly, perfluoro. The application of the alkyl polyether significantly improves the process problems caused by the tape mask method, and significantly improves the productivity of deposition and the quality of the obtained product. The method of the present invention, when using a conductor as a deposition material, a metallized film for a capacitor,
In addition to having a remarkable effect on the manufacture of electrical components such as a transparent electrode plate, it is also suitable for the manufacture of products that require a patterned vapor-deposited film, such as decorative materials, packaging materials, and filters.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an internal front view of a semi-continuous production apparatus for a metallized film for a capacitor by vacuum evaporation of a tape mask method, and FIG. FIG. 3 is a partial plan view, and FIG. 3 is a perspective view of a spray application nozzle as an example of a preferred oil application device. DESCRIPTION OF SYMBOLS 1 ... Original film roll, 2 ... Pulled-out film, 3 ... Cooling can, 4 ... Take-up roll, 5 ... Evaporation source, 6 ... Tape guide roll (plural), 7 ... Masking Tape, 8 ... oil application device (8a ... slit-shaped opening), 9 ... deposited film, 10 ... deposited part, 11 ... non-deposited part.

Claims (1)

(57) [Claims] When performing vacuum deposition while masking a predetermined portion of the traveling deposition base material with a masking tape, the masking tape is caused to travel together with the deposition base material while being in contact with the deposition base material, and the deposition tape is upstream from the deposition position in the vacuum deposition chamber and the deposition is performed. Spraying or contact-transferring an evaporation-preventing oil onto the surface of the masking tape that is exposed to the vapor of the evaporation material at a position upstream of the contact start position with the base material, and using perfluoro as the evaporation-preventing oil. A vacuum deposition method using an alkyl polyether. 2. The average molecular weight of the perfluoroalkyl polyether is 10
2. The vacuum deposition method according to claim 1, wherein the method is in the range of 00 to 15,000. 3. The perfluoroalkyl polyether is represented by the following formula (I)
(III) formula _{(I) C 3 F 6 O} n Formula _{(II) C 3 F 6 O} n CF 2 O m Formula _{(III) C 2 F 4 O} n CF 2 O m ( where n, m are, par The repeating unit represented by the formula (1), which gives an average molecular weight of 1000 to 15,000 as a whole of the fluoroalkyl polyether), or a mixture of two or more of these repeating units. The vacuum vapor deposition method according to the paragraph. 4. The vacuum deposition method according to any one of claims 1 to 3, wherein the deposited film is a conductor.