JPH11236668A - Thin film forming device and vacuum deposition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the producting time and to improve operating ratio and productivity by moving one of members for preventing the deposition onto the unnecessary part of a belt-like member along the outer circumferential face of a rotary can. SOLUTION: A rotary mask 20 is composed of four mask units 21 to 24 fitted in freely attachably and detachably to a rotatable axis 18. A fixed mask 4 has openings 21b to 24b regulating the vapor depositing region corresponding to an opening 4a, and a magnetic material evaporated from a heat generating source 3 passes through the opening 21b of the rotary mask 20 and the opeing 4a of the fixed mask 4 and is deposited into the surface of a film 2 to form a thin film. Since, as the depositing process progresses, the deposited materials in a mask unit, particularly, at the lower part 21a' increase, till the time when the quantity of the deposited materials reach the prescribed amount or when the mask unit 22 reaches the initial position of the mask unit 21 for every predetermined film length, the rotary mask 20 is turned to turn the mask units 23 and 24 successively, thereby the deposition is executed. In this way, the deposited materials on the mask units 21 to 24 is prevented from being excessively grown.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for continuously forming a thin film on a belt-like substrate in a vacuum chamber, and a vacuum for forming a thin film by melting and evaporating a film-forming material and depositing the material on the substrate. It relates to a vapor deposition device.

[0002]

2. Description of the Related Art Various means have been developed for forming a thin film made of a different material on the surface of a base material. Among them, a vacuum deposition process is widely used. is there. The substrate used is, for example, a plate-like material such as glass, but in addition, a material obtained by vapor-depositing the surface of a flexible substrate such as a polymer film is a packaging material,
It is used in the field of decorative materials and magnetic recording media.

When vacuum deposition is performed on a polymer film as described above, a film serving as a substrate is usually wound in a roll form of several thousands to tens of thousands of meters, and the roll is set in a vacuum chamber. , One roll is continuously deposited. At this time, if the heat resistance of the polymer film as the base material is not sufficient, a cooled cylindrical rotating can is provided in the vacuum chamber, and the film base of the vapor deposition portion is adhered to the outer peripheral surface of the rotating can. It is common to let them. In such an apparatus, it is necessary to cover the edge portion of the film substrate so that the vapor deposition material does not adhere to the cooled rotary can. Further, when a magnetic recording medium is manufactured by using such a vacuum evaporation apparatus, the incident angle of the evaporating flying particles with respect to the film substrate is required due to the requirement of the electromagnetic conversion characteristics of the obtained magnetic recording medium. Must be strictly regulated.
In each case, a cover is provided in the vicinity of the deposition portion in order to prevent deposition on an inappropriate portion. Such a cover is usually referred to as a mask (including a protection mask, a protection plate, a shielding plate, etc.) or a protection member.

FIG. 2 shows a conventional vacuum deposition apparatus, specifically,
FIG. 2 is a diagram showing a deposition prevention structure of a main part of a vapor deposition unit in a vacuum vapor deposition apparatus for manufacturing a magnetic recording medium such as a magnetic tape as an example, and an outer peripheral surface of a cylindrical rotary can 1 disposed in a vacuum chamber. The substrate material, that is, the film 2 moves while being in close contact with the substrate material. Below the rotary can 1, an evaporation source of the magnetic material, for example, a crucible 3 containing the magnetic material is provided, and a wear-protecting member, that is, a mask 4, is provided so as to cover the vicinity of the deposition portion of the rotary can. ing. The mask 4 has an opening 4 a for regulating a deposition area on the film 2.
And is detachably attached to, for example, a reference plate 5 in a vacuum chamber that supports the traveling system.

[0005]

In the above-described apparatus, when vapor deposition is continuously performed on a long film, the amount of deposits due to ineffective vapor on the mask gradually increases, and as a result, a large amount of deposits is formed. Therefore, there is a problem that the deposition process is hindered. More specifically, the deposit 4 grows as the film deposition time elapses, and the opening 4a of the mask becomes narrower, or dust is generated due to the drop of the lump of the deposit, and the deposit 4 drops to the evaporation source, for example, the crucible 3. The scattering of the molten material due to the above-mentioned phenomenon occurs. Therefore, there is a limit to the processing length at which continuous vapor deposition can be performed. To solve this problem, the vacuum in the apparatus is periodically released, the vacuum chamber is released, and at the same time, the evaporation source 3 is removed. It is necessary to take any means, such as removing the deposits by interrupting the heating, or removing the mask 4 and replacing it with a separately prepared mask of the same shape. However, in any case, in order to restart the vapor deposition, the inside of the apparatus needs to be evacuated again and the crucible 3 needs to be reheated, which requires a great deal of labor and time. There is a problem that the rate and productivity are significantly reduced.

[0006] Further, in a manufacturing apparatus of a magnetic recording medium such as a magnetic tape, a method of heating an evaporation source by an electron beam is used, and since the evaporation material is a ferromagnetic material, such a ferromagnetic material is used. If the deposit grows over time, it affects the magnetic field for controlling the electron beam, and as a result, there is a problem that it is difficult to control the position of the electron beam. Therefore, also in this case, there is a limit to the processing length that enables continuous vapor deposition, that is, the continuous production time, which results in an increase in production cost.

[0007]

SUMMARY OF THE INVENTION The present inventor has made various studies to solve the above problems and to improve the operation rate and productivity of the apparatus without increasing the production cost. At least one of the anti-wear members is provided with a movable mechanism, and the idea is that if the mask moves at predetermined time intervals, it is possible to prevent the growth of the attached matter at one location.

That is, according to the present invention, there is provided a thin film forming apparatus which comprises a cylindrical rotary can in a vacuum chamber and continuously forms a thin film on a strip-shaped substrate moving along the outer peripheral surface of the rotary can. An anti-wear member for preventing the band-shaped base material from adhering to an unnecessary portion is provided, and a mechanism is provided in which at least one of the anti-wear members moves along the outer peripheral surface of the rotary can. Provided.

Further, a cylindrical rotary can in a vacuum chamber, an evaporation source of a vapor deposition material facing a strip-shaped base material moving along the outer peripheral surface of the cylindrical rotary can, and A deposition member for partially blocking the vapor flow of the vapor deposition material reaching the material and preventing adhesion to unnecessary portions, wherein at least one of the deposition prevention members has an outer periphery of the rotary can. Also provided is one with a mechanism for moving along a surface.

In each of the above constructions, one of the wear prevention members has a curved surface corresponding to the outer peripheral surface of the cylindrical rotary can, and the curved surface is rotatable along the outer peripheral surface of the rotary can. It is preferable to adopt a structure in which the shaft is supported.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be widely used as an apparatus for forming a thin film on the surface of a substrate in a vacuum chamber, and among them, a vacuum evaporation apparatus, and further, a ferromagnetic material is used as an evaporation material. The present invention is particularly useful as an apparatus for manufacturing a magnetic recording medium to be used.

Hereinafter, a magnetic tape manufacturing apparatus will be described as an example. FIG. 1 is an example of a configuration of a vacuum evaporation apparatus used in a manufacturing process of a magnetic tape.
The same components as those described above are denoted by the same reference numerals. The film 2 is unwound from the supply roll 6 in the vacuum chamber, and the guide rolls 7 to 11, the rotary can 1, and the guide roll 1
After passing through 2 and 13, it is wound on a winding roll 14. Between the guide rolls 10 and 11, there is provided a pre-processing device 15 for charging the film 2 to make it adhere to the surface of the rotary can, and a post-processing device 16 for discharging the film 2 before the guide roll 12 is provided. And guide roll 12
At the subsequent stage, post-processing devices 17 for removing wrinkles of the film 2 are provided.

On the outer peripheral surface of the rotary can 1, there is provided an anti-adhesion mechanism comprising the fixed mask 4 and the rotary mask 20 so as to cover the rotary can 1. The fixed mask 4 has a conventional structure, and has an opening 4a for regulating the deposition region. The rotary mask 20
For example, it comprises a plurality of, here four mask units 21 to 24 which are coaxial with the axis of the rotary can 1 and which are detachably attached to a shaft 18 which is rotatable separately therefrom. In each of the mask units 21 to 24, curved surfaces 21a to 24a are formed along the outer peripheral surface of the fixed mask 4, and the curved surfaces 21a to 24a are provided with openings 4a of the fixed mask 4.
Corresponding to the openings 21b to 21b for regulating the deposition region
4b are formed respectively. As shown in the figure, the material evaporated from the crucible 3 containing the magnetic material placed below the rotary can 1 is supplied to the opening 21b of the mask unit 21 of the rotary mask 20 and the opening 4a of the fixed mask 4.
And adheres to the surface of the film 2. In the drawing, reference numeral 19 denotes a shielding plate for preventing the material evaporated from the evaporation source 3 from scattering to the left in the drawing.

In the vapor deposition apparatus having such a configuration, upon the start of vapor deposition, the cooled rotary can 1 rotates clockwise as indicated by the arrow in the figure, and the rotary mask 20 is moved to the position shown initially, that is, Are set so that the opening 21b of the mask unit 21 corresponds to the opening 4a of the fixed mask 4. The heated magnetic material evaporates from the evaporation source 3 and reaches the surface of the film 2 via the opening 21b of the mask unit 21 of the rotary mask 20 and the opening 4a of the fixed mask to form a thin film. As the deposition process progresses, the amount of deposits particularly on the lower surface 21a 'of the curved surface 21a of the mask unit 21 increases, so that when the amount of deposits becomes a predetermined amount, or at every predetermined film processing length. , Until the mask unit 22 comes to the original mask unit 21 position.
Is turned (counterclockwise direction indicated by an arrow in the figure).
Hereinafter, vapor deposition is performed by sequentially rotating the mask units 23 and 24 in the same manner.

As described above, by rotating the rotary mask 20 sequentially and arranging a new mask unit in the deposition area, the residence time of the mask in the area where the amount of deposits is large is limited. Therefore, the deposits are prevented from growing excessively. Therefore, the film processing length, that is, the continuous production time can be significantly increased as compared with the conventional case, and the operation rate and productivity of the apparatus are improved. Note that the influence of the arrangement of the rotary mask 20 on the fixed mask 4 on the film formation step on the film is such that the film formation portion of the film 2 is slightly changed in the width direction of the film (the direction perpendicular to the paper surface). It was only affected and did not affect the quality of the magnetic tape. Further, here, the case where the rotary mask 20 is a divided type including four mask units has been described, but the number of units is not particularly limited. In addition, the rotary mask may be an integral type instead of such a split type. However, from the viewpoint of handling and maintenance, it is more advantageous to use the split type.

<Embodiment> In the apparatus shown in FIG. 1, the diameter of the rotating can 1 is 1000 mm, the width is 600 mm, the width of the film 2 is 580 mm, and the film forming width is 550 m.
m, and the width of the evaporation source 3, ie, the crucible, is 700 mm
And The melting and vapor deposition of the magnetic material in the crucible has an output of 30
A pierce-type electron gun with 0 kW and 90 ° deflection was used. All the units 21 to 24 of the fixed mask 4 and the rotary mask 20 were made of stainless steel having a thickness of 15 mm. In addition, near the crucible, a deflecting magnet necessary for proper incidence of the electron beam was installed. The following experiments were performed using this apparatus.

(Experiment 1) 10 μm thick as a substrate for vapor deposition
PET (polyethylene terephthalate) film
Using pure cobalt as an evaporation material, a film was formed under the conditions of a running speed of the substrate film of 100 m / min and a film thickness of 0.2 μm. The vapor concentration of the material on the crucible was monitored by an atomic absorption monitor so that the material evaporated according to the initial conditions, and the evaporation amount was kept constant. Under these conditions, cobalt was formed on a 15000 m base film using only a fixed mask. As a result of observing the state of adhesion and deposition on the fixed mask and the position of the electron beam in the crucible in this process, it was found that it was difficult to control the position of the electron beam at the crucible longitudinal edge when the continuous film formation processing length was about 10500 m. became. Further, the deposited material fell after the film forming process of about 12000 m, and it was impossible to continue the film forming between 12000 and 15000 m. From the above results, when a good quality magnetic tape is manufactured using only the fixed mask, the continuous film formation processing length is 10500 to 12000 m, and further considering the danger and yield, the continuous film formation processing length is limited to 10,000 m. Was confirmed.

(Experiment 2) A new fixed mask prepared separately was attached to the above-described apparatus, and a rotary mask composed of four units was attached thereon, and film formation was performed under the same conditions as in Experiment 1. Was. Base film is 500
Set a length of 00m and set the film forming process length to 10,000.
The rotary mask was rotated every m so that the opening of the next mask unit was adjusted to an appropriate position. Continuous processing length 4
After 0000m, use only fixed mask and
It was possible to form a film continuously over the entire area of m without any problem such as falling of the deposit. In addition, the position control of the electron beam has never been disabled.

From these results, in the vapor deposition apparatus using the rotary mask of the present invention in combination with the fixed mask, the continuous processing length of the base material can be extended about five times as compared with the conventional vapor deposition apparatus using only the fixed mask. It became possible and the continuous processing time was greatly increased, so that it was confirmed that the operation rate and productivity of the apparatus were dramatically improved.

[0020]

As described in detail above, according to the present invention, the processing length for continuously forming a film by using a movable anti-wear member, that is, the continuous production time is dramatically increased. Therefore, the operation rate and productivity of the apparatus can be greatly improved. In particular, by applying the present invention to a magnetic recording medium manufacturing apparatus that deposits a magnetic material on a film, a high-quality recording medium can be efficiently produced, which is extremely effective in reducing the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of a vacuum deposition apparatus which is an example of a thin film forming apparatus of the present invention.

FIG. 2 is a perspective view of a main part for describing a deposition prevention structure in a conventional vacuum deposition apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotating can 2 strip-shaped base material (film) 3 evaporation source (crucible) 4 fixed mask 4a opening 5 reference plate in vacuum chamber 6 supply roll 7-13 guide roll 14 winding roll 15 pre-processing device 16, 17 post-processing device 18 axis 19 shielding plate 20 rotary mask 21-24 mask unit 21b-24b opening

Claims (4)

[Claims] 1. A cylindrical rotating can provided in a vacuum chamber,
In a thin film forming apparatus for continuously forming a thin film on a strip-shaped base material moving along the outer peripheral surface of the rotary can, an anti-wear member for preventing adhesion of the strip-shaped base material to unnecessary portions is arranged. And a mechanism for moving at least one of the attachment members along the outer peripheral surface of the rotary can. 2. The anti-wear member has a curved surface corresponding to an outer peripheral surface of the cylindrical rotary can, and a pivotal support such that the curved surface is rotatable along the outer peripheral surface of the rotary can. The thin film forming apparatus according to claim 1, wherein: 3. A cylindrical rotary can in a vacuum chamber, an evaporation source for a vapor-deposited material facing a strip-shaped substrate moving along the outer peripheral surface of the cylindrical rotary can, and A deposition member for partially blocking a vapor flow of the vapor deposition material to prevent adhesion to unnecessary portions, wherein at least one of the deposition prevention members has an outer peripheral surface of the rotary can. A vacuum vapor deposition device comprising a mechanism that moves along a line. 4. The anti-wearing member has a curved surface corresponding to the outer peripheral surface of the cylindrical rotary can, and is pivotally supported such that the curved surface is rotatable along the outer peripheral surface of the rotary can. The vacuum evaporation apparatus according to claim 3, wherein