JPH0841644A - Thin film forming device - Google Patents

Abstract

PURPOSE:To provide a thin film forming device which is capable of forming thin films made uniform in film thickness and film quality and is capable of producing a magnetic tape which is excellent not only in still durability and weatherability but in shuttle characteristics as well when the device is applied to formation of the protective film for the magnetic tape. CONSTITUTION:This thin film forming device is constituted to deposit thin film forming material particles on the flexible base traveling along the peripheral surface of a cylindrical can 6 disposed to face a target 10 disposed on a cathode electrode 9 above this target by sputtering the target 10. A deposition protective plate 11 for limiting the range where the thin film forming material particles are deposited is disposed near the cylindrical can 6. The aperture 12 of this deposition protective plate 11 is so limited that the distance F from the intersected point (p) of a straight line l2 connecting the terminal of the target 10 and the terminal of the aperture 12 and the peripheral surface of the cylindrical can 6 to a straight line 11 dropped perpendicularly from the center of the cylindrical can 6 toward the target 10 attains 0.5W<=F<=W when the target length is defined as W.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus for forming a thin film on the surface of a flexible support by a sputtering method, and particularly to a thin film forming apparatus having a structure capable of forming a thin film having a uniform film thickness and film quality. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, vapor deposition, sputtering, CVD and the like have been studied as vacuum thin film forming methods and have been put to practical use in various fields. The vapor deposition method and the CVD method have a high film formation rate, and particularly, the vapor deposition method has an advantage that a high speed film formation is possible by using an EB gun. However, since this vapor deposition method is a method of vaporizing and depositing metal, there is a problem that it is difficult to simultaneously and stably deposit substances having different vapor pressures.

On the other hand, the sputtering method has attracted attention because it can form alloy films of various metals having different vapor pressures. For example, it is used for magnetic tapes used in digital video tape recorders, commercial video tape recorders and data storage. Application to the formation of a protective film in a magnetic recording medium such as a magnetic tape which requires extremely high durability has been studied. Specifically, SiO ₂ , SiN _x , C, S
It has been known that forming a wear resistant material such as iC as a protective film improves running durability and corrosion resistance of the magnetic recording medium.

Conventionally, the above-mentioned sputtering method has a problem in that it is inferior in productivity because it is inferior in film forming rate to the vapor deposition method, and the apparatus becomes large in size for mass production. Then, the film forming speed is increasing due to the development of the sputtering method such as the magnetron sputtering method and the facing target method. FIG. 1 shows a thin film forming apparatus to which the sputtering method is applied. In this thin film forming apparatus, the exhaust port 1
In the vacuum chamber 2 having a and 1b, a traveling system for traveling the flexible support 5 and a film forming system for forming a thin film on the flexible support 5 are provided. The above running system,
It is composed of a feed roll 3, a winding roll 4, a cylindrical can 6, and guide rolls 7 and 8. By rotating at a constant speed in the direction of the arrow in the figure, the flexible support 5 is sequentially fed from the feed roll 3 to form a cylindrical can. After traveling along the peripheral surface of 6, the winding roll 4 is wound up.

On the other hand, the film forming system is provided below the vacuum chamber 2 partitioned by a partition plate, and the cathode electrode 9 is provided below the cylindrical can 6, and the raw material of the thin film disposed on the surface of the cathode electrode 9. The target 10 and the gas introduction pipe. The cathode electrode 9 is connected to a power source (not shown), and a magnet is arranged below the cathode electrode 9.

Then, in order to form a thin film by the apparatus having the above structure, a predetermined electric power is supplied to the cathode electrode 9 while the flexible support 5 is running in the running system described above. To do. As a result, an electric discharge is generated between the flexible support member 5 and the cylindrical can 6, and the gas supplied from the gas introduction pipe is ionized and attacks the target 10.
Thin film material particles adhere to the surface.

[0007]

However, when a protective film for a magnetic recording medium is formed using the above-described thin film forming apparatus, the manufactured magnetic recording medium is excellent in running durability and corrosion resistance. However, it was found that after a large number of running tests (shuttle test), the protective film fell off and adhered to the magnetic head, causing dropouts and short clogs (instantaneous clogs) of a few seconds.

This is because the flexible support 5 is the target 10.
Even when a thin film is formed with a uniform film thickness and film quality when traveling in a position facing the position, when traveling on the downstream side, the thin film material particles adhere unevenly,
As a result, it is considered that the cause is that the film thickness and film quality of the thin film become non-uniform. In order to solve such a problem, an adhesion-preventing plate 11 is provided between the target 10 and the peripheral surface of the cylindrical can 6 for limiting the adhesion range of the thin-film material particles blown out from the target. Although it was considered, it was difficult to optimize this adhesion range, and a sufficient improvement effect was not seen.

Therefore, the present invention has been proposed in view of the above conventional circumstances, and a thin film forming apparatus capable of forming a thin film with a uniform film thickness and film quality by optimizing the deposition range of thin film material particles. The purpose is to provide.

[0010]

A thin film forming apparatus according to the present invention has been proposed to achieve the above-mentioned object, and a target provided on a cathode electrode is sputtered to produce a thin film of the target. In a thin film forming apparatus for forming a thin film by depositing thin film material particles on a flexible support running along the peripheral surface of a cylindrical can facing upward, deposition of thin film material particles in the vicinity of the cylindrical can. An adhesion-preventing plate that limits the range is provided, and the opening of the adhesion-preventing plate is from the intersection of the straight line connecting the end of the target and the end of the opening and the circumferential surface of the cylindrical can to the center of the cylindrical can. The distance to a straight line that is vertically lowered toward the target is regulated so as to be ½ or more of the target length and not more than the target length.

That is, as shown in FIG. 2, paying attention to the downstream side of the straight line l ₁ which is vertically lowered from the center of the cylindrical can 6 toward the target 10, the end of the target 10 (the most downstream end) and the protection line are prevented. A straight line l ₂ connecting the end (the most downstream end) of the opening 12 of the attachment plate 11 is a line separating the thin film material particles that can pass through the opening 12 and the thin film material particles that are blocked from passing through. Therefore, only the thin film material particles inside the straight line l ₂ can adhere to the flexible support, and the adhesion range of the thin film material particles to the flexible support is
The range is inside the intersection p between the above l ₂ and the peripheral surface of the cylindrical can 6. Therefore, if the distance from the intersection point p to the straight line l ₁ is F and is regulated, it becomes possible to regulate the adhesion range of the thin film material particles to the flexible support on the downstream side.

When the adhesion range of the thin film material particles is represented by F and the target length is W, the relationship between the two is W / 2.
The opening of the deposition preventive plate may be regulated so that ≦ F ≦ W. When the adhesion range F is larger than W, the effect of restricting the adhesion range F is reduced and the effect of making the film thickness and film quality uniform is lost. On the contrary, if the adhesion range F is reduced, it is necessary to reduce the film formation rate in order to adhere the thin film material particles having a desired film thickness, and if it is smaller than W / 2, there is a problem in productivity. In addition, since the proportion of thin film material particles that can adhere to the flexible support is reduced, the target 1
The yield of 0 deteriorates.

The deposition preventive plate 11 is usually provided with the same opening amount and blocking amount on the upstream side and the downstream side with respect to the straight line l _1, but on the upstream side with respect to the opening amount on the downstream side. It is also possible to make modifications such as increasing the opening amount of. In addition,
Not only the regulation of the opening 12 of the deposition preventive plate 11 but also the optimization of the distance d between the target 10 and the circumferential surface of the cylindrical can 6 (hereinafter referred to as the distance between the bases), excellent film quality, and efficient thin film Necessary for good formation. This is because if the distance between the substrates is too large, the film forming rate deteriorates, and if it is too small, the discharge between the cathode electrode 9 and the cylindrical can 6 is not stable. For example, when the diameter of the cylindrical can 6 is 600 mm and the target length W is 240 mm, the distance d between the substrates is preferably 200 mm or less from the viewpoint of the film forming rate. Further, in order to dispose the deposition-inhibitory plate 11 between the cylindrical can 6 and the target 10, the inter-base distance d needs to be at least 6 mm or more, and in order to stabilize the discharge, 1 is required.
5 mm or more is suitable.

By the way, the flexible support on which a thin film is formed by the thin film forming apparatus of the present invention is a long film on which a metal magnetic thin film is formed. That is, the formed thin film is a protective film provided on the metal magnetic thin film in a so-called vapor deposition tape. Any conventionally known material can be used as the material of the protective film, such as CrO ₂ and Al.
₂ O ₃ , BN, Co oxide, MgO, SiO ₂ , Si _{3
O 4, SiN x, SiC,} SiN x -SiO 2, ZrO
₂ , TiO ₂ , TiC and the like can be mentioned, but carbon is typical. Further, the protective film may be a single layer film of these, a multilayer film or a composite film with a metal.

When a vapor deposition tape is manufactured using the thin film forming apparatus according to the present invention, any conventionally known material can be used as the material of the metal magnetic thin film.
Ferromagnetic metal materials such as Fe, Co and Ni, Fe-Co and C
o-Ni, Fe-Co-Ni, Fe-Cu, Co-C
u, Co-Au, Co-Pt, Mn-Bi, Mn-A
1, Fe-Cr, Co-Cr, Ni-Cr, Fe-Co
Examples include ferromagnetic alloy materials such as -Cr, Co-Ni-Cr, and Fe-Co-Ni-Cr. The metal magnetic thin film may be a single layer film or a multilayer film of these.

Further, the adhesion is improved between the non-magnetic support and the metal magnetic thin film, or between the layers in the case of a multilayer film,
In addition, an underlayer or an intermediate layer may be provided to control the coercive force. Further, for example, the vicinity of the surface of the magnetic layer may be an oxide to improve the corrosion resistance. It is also possible to use the thin film forming apparatus of the present invention for forming the metal magnetic thin film, the underlayer and the intermediate layer.

Of course, the structure of the magnetic recording medium manufactured by the thin film forming apparatus of the present invention is not limited to this. For example, a back coat layer may be formed if necessary, or a magnetic recording medium may be formed on a non-magnetic support. Forming a coating layer, lubricant,
There is no problem in forming a layer such as an anticorrosive agent. In this case, as the material contained in the non-magnetic pigment, the resin binder or the lubricant, and the rust preventive agent layer contained in the back coat layer, any conventionally known materials can be used.

Further, by applying the thin film forming apparatus of the present invention,
Other metal thin films can be formed, for example, Au, Cr, Ti, Cu, Mo, Mn, Bi, A on the substrate.
It may be used for forming a thin film of a metal such as g or Pt or an alloy thereof. A sputtering apparatus using a magnetron sputtering method or a facing target method can be applied to the thin film forming apparatus according to the present invention. In particular, a magnetron sputtering device in which a magnet is arranged below or on the side of the target is preferable, and a leakage magnetic field from the magnet traps electrons to sustain discharge, so that the target is efficiently sputtered. It is possible to improve the film forming speed. It should be noted that an auxiliary magnet may be further arranged around the target of the above device so as to improve the bias of the magnetic field distribution, whereby the target can be used uniformly and the yield of the target is improved. You can

[0019]

In the thin film forming apparatus according to the present invention, the range in which the thin film material particles beat out from the target adhere to the flexible support is optimized by the adhesion preventing plate, so that the uniform film thickness and film quality can be obtained. A thin film can be formed. In particular, since the thin film material particles attached on the most downstream side with respect to the flexible support have a great influence on the film quality of the surface layer of the thin film, it is possible to optimize the position of the end of the opening of the deposition preventive plate. A thin film having excellent film quality can be obtained.

Therefore, when the thin film forming apparatus according to the present invention is applied to the formation of a protective film on a magnetic tape, a protective film having a uniform film thickness and film quality can be formed on a running flexible support.

[0021]

EXAMPLES Hereinafter, specific examples of the present invention will be described, but the present invention is not limited to these examples. Here, a magnetron sputtering device was used as a thin film forming device to form a protective film on a so-called vapor deposition tape. Example 1 In this example, a thin film forming apparatus was used in which the relationship between the adhesion range F and the target length W was F = 0.5W.

FIG. 1 shows an example of the structure of a thin film forming apparatus. In this apparatus, a traveling system for traveling the flexible support 5 in a vacuum chamber 2 having exhaust ports 1a and 1b, and a film forming system for forming a thin film on the flexible support 5 And are provided. The traveling system is provided with a feed roll 3 that rotates at a constant speed in the direction of arrow a in the figure and a winding roll 4 that also rotates at a constant speed in the direction of arrow b in the figure. The tape-shaped flexible support 5 is attached to the winding roll 4.
Are designed to run sequentially.

A cylindrical can 6 having a diameter (600 mm) larger than the diameter of each of the rolls 3 and 4 is provided in the middle of the travel of the flexible support 5 from the feed roll 3 to the winding roll 4 side. Is provided. The cylindrical can 6 is provided so as to pull out the flexible support 5 downward in the drawing,
It is configured to rotate at a constant speed in the direction indicated by arrow c in the figure. The feed roll 3, the winding roll 4, and the cylindrical can 6 are cylindrical bodies each having a length substantially the same as the width of the flexible support 5, and the cylindrical can 6 includes
A cooling device (not shown) is provided inside so that deformation of the flexible support 5 due to a temperature rise can be suppressed.

Therefore, the flexible support 5 is sequentially fed from the feed roll 3, and the cylindrical can 6 is further fed.
It travels along the peripheral surface of and is wound up by the winding roll 4. Guide rolls 7 and 8 are provided between the feed roll 3 and the cylindrical can 6 and between the cylindrical can 6 and the winding roll 4, respectively, and run along the cylindrical can 6. Flexible support 5
A predetermined tension is applied to the flexible support 5 so that the flexible support 5 runs smoothly.

Although the cylindrical can 6 is cooled in this embodiment, it may be appropriately heated to increase the adhesive strength between the flexible support and the thin film. For the same purpose, a bombarding process may be performed in advance before film formation. on the other hand,
The film forming system is provided on the lower side of the vacuum chamber 2 partitioned by a partition plate, and is provided on the cathode electrode 9 provided below the cylindrical can 6, the target 10 made of the raw material for the thin film disposed on the surface of the cathode electrode 9. It is composed of a deposition-inhibiting plate 11 that regulates the adhesion range F of the thin-film material particles blown out from the target 10 and a gas introduction pipe.

A power source (not shown) is connected to the cathode electrode 9, and a magnet is arranged below the cathode electrode 9. Further, a cooling pipe (not shown) for supplying and discharging cooling water is connected to the cathode electrode 9 so that heating of the cathode electrode 9 target 10 can be prevented by circulating the cooling water. The target 10 is provided so as to face directly below the cylindrical can 6, and as shown in FIG. 2, a straight line l ₁ connecting the center of the cylindrical can 6 and the center of the target 10 coincides with the vertical direction. There is. In the target 10, the length of the flexible support 5 in the traveling direction (target length)
W is 240 mm, and the distance (inter-substrate distance) d between the upper surface of the target 10 and the peripheral surface of the cylindrical can 6 is 100 mm.

Further, the deposition preventive plate 11 is provided between the cylindrical can 6 and the target 10 in the vicinity of the cylindrical can 6, and regulates the adhesion range F of the thin film material particles adhering to the flexible support 5. The opening amount and the blocking amount are equal on the upstream side and the downstream side with respect to the straight line l ₁ . As shown in FIG. 3 which is a bottom view of the deposition preventive plate 11, the deposition preventive plate 11 prevents the thin film material particles from adhering to both edges of the flexible support 5 in the width direction. At the same time, the thin film material particles are masked so as not to adhere to the flexible supports 5 on the upstream and downstream sides of the predetermined range.

Then, the opening 12 of the deposition preventing plate 11 is
Assuming that an intersection point p is a straight line l ₂ connecting the end (the most downstream end) of the target 10 and the end (the most downstream end) of the opening 12, a straight line l ₁ from the intersection p. Distance (adhesion range F) to 120 mm (target length W
Is 0.5 W). Therefore, in the above-described thin film forming apparatus, when the cathode chamber 9 is supplied with electric power and the gas is supplied from the gas introducing pipe while the vacuum chamber 2 is kept at a certain degree of vacuum, the space between the cathode can 9 and the cylindrical can 6 is reduced. The discharge is caused to ionize the gas, and the target 10 is attacked by the ions, whereby the thin film material particles are knocked out. Then, the thin film material particles are adhered to the surface of the running flexible support 5 while the predetermined range is masked by the deposition preventing plate 11. The leakage magnetic field generated by the magnet traps electrons and sustains the discharge, enabling efficient sputtering.

The apparatus having the above-mentioned structure was applied to the formation of a protective film on a magnetic recording medium, and a magnetic tape was produced as follows. First, by using a general continuous winding type oblique vapor deposition apparatus on a non-magnetic support having an undercoat, C
An o-Ni-based metal magnetic thin film was applied. The base, undercoat and vapor deposition conditions used are as follows.

Non-magnetic support conditions Base: Polyethylene terephthalate 10 μm thickness 150 mm width Undercoat: Water-soluble latex mainly composed of acrylic ester is applied. Protrusion density: about 10 million pieces / mm ² Vapor deposition conditions Ingot: Co80-Ni20 (number) Is the weight ratio of each metal) Incident angle: 45 to 90 ° Tape speed: 0.17 m / sec Magnetic layer thickness: 0.2 μm Vacuum degree: 7 × 10 ^-2 Pa Next, protected by the thin film forming device described above. A film was formed. The sputtering conditions are shown below.

Sputtering conditions Method: DC magnetron sputtering method Target: Carbon Gas used: Argon Background vacuum degree: 4 × 10 ⁻³ Pa Vacuum degree during film formation: 2 Pa Tape speed: 0.06 m / sec Protective film thickness: 15 nm Input power: 10 w / cm ² Further, a back coat and a top coat were applied according to the following conditions, and the tape was cut into a predetermined tape width to obtain a magnetic tape.

Back coat: Carbon and Ure
A mixture of a tan binder is applied in a thickness of 0.6 μm. Top coat: Perfluoropolyether is applied Slit width: 8 mm width
It was sample tape. Examples 2-5 In these examples, the adhesion range F is larger than that in the first example.
A thin film forming apparatus was used.

Specifically, the adhesion range F and the target length W
And F = 0.7W, 0.83W, 0.9W, 1.
A protective film was formed using a thin film forming apparatus having the same configuration as that described in Example 1 except that it was set to 0 W. However, the film forming rate was appropriately adjusted in order to form a protective film having a thickness of 0.015 μm. Then, a magnetic tape was produced in the same manner as in Example 1 to obtain sample tapes of Examples 2-5. Examples 6 to 11 In these examples, the thin film forming apparatus was used in which the adhesion ranges F were all the same but the inter-substrate distances d were different.

Specifically, the adhesion range F and the target length W
Are all F = 0.83 W, and the distance d between the substrates is 3 mm, 6 mm, 15 mm, 80 mm, 190 mm, 2
A protective film was formed using a thin film forming apparatus having the same configuration as described in Example 1 except that the thickness was 30 mm. However, the film forming rate was appropriately adjusted in order to form a protective film having a thickness of 0.015 μm. Then, magnetic tapes were produced in the same manner as in Example 1 to obtain sample tapes of Examples 6 to 11. Comparative Examples 1 to 3 In these comparative examples, the thin film forming apparatus having the adhesion range F smaller than 0.5 W or larger than W was used.

Specifically, the adhesion area F and the target length W
The protective film is formed by using the thin film forming apparatus having the same configuration as that described in Example 1 except that the relations with F are 0.4 W, 1.1 W, and 1.5 W. .015
The film formation rate was appropriately adjusted to form a protective film having a thickness of μm. Then, magnetic tapes were produced in the same manner as in Example 1 to obtain sample tapes of Comparative Examples 1 to 3. Comparative Examples 4 and 5 The sample tapes of Comparative Example 4 were subjected to protective film formation by using a thin film forming apparatus having the same configuration as described in Example 1 except that the deposition preventive plate 11 was not provided. It is a magnetic tape manufactured in the same manner as. However, at the time of forming the protective film, the film forming rate was adjusted in order to form the protective film having a thickness of 0.015 μm. On the other hand, the sample tape of Comparative Example 5
No protective film was formed, and other steps were performed in
It is a magnetic tape manufactured in the same manner as. Evaluation of characteristics For the sample tape manufactured as described above,
In addition to examining the still durability and weather resistance, as the shuttle characteristics, powder falling on the magnetic head and instantaneous clog were examined.

Specifically, the still durability was measured by using a modified model of 8 mm VTR EV-S900 manufactured by Sony Corporation, based on the time when the output dropped by 3 dB or more from the reproduction output level. Was evaluated. Further, the weather resistance was evaluated by determining the deterioration rate Δφs of the magnetic properties by the equation (1), with φs being the measured value before the corrosion test and φs ′ being the measured value after the corrosion test.

Δφs = (φs−φs ′) / φs × 100 (%) (1) In the corrosion test, a gas corrosion tester was used, and an atmosphere containing SO ₂ gas 0.3 ppm (temperature 30 ° C., Relative humidity 90
%) For 24 hours. Also,
The magnetic characteristics φ s and φ s ′ were measured using a sample vibration type magnetic characteristic measuring device (VSM).

Further, for the measurement of the shuttle characteristics, similarly, a product made by Sony Corporation, trade name: 8 mm VTR EV-S90 is used.
9 when running 100 times for 2 hours using a 0 remodeling machine
The output level during 10 runs from 0 to 100 was recorded on a pen recorder, and the instantaneous clogs generated within the measurement time of 10 times x 2 hours = 20 hours were counted. In addition,
This instantaneous clog was defined as the number of times that output attenuation of 6 dB or more occurred for 1 second or more. After traveling 100 times, the state of powder falling onto the magnetic head was observed with a microscope. This powder drop is at a level where no deposits on the magnetic head can be confirmed at all, there is some deposits, and a level at which instantaneous clogs are considered to occur depending on the conditions is Δ, and a large amount of deposits from the instantaneous clogs. The level at which complete clogs could occur was evaluated as relative to x.

Table 1 shows the measurement results of the sample tapes of Examples 1 to 5 and the sample tapes of Comparative Examples 1 to 5 together with the adhesion range F in the thin film forming apparatus used.

[0040]

[Table 1]

[0041]

[Table 2] From Table 1 and Table 2, as compared with the sample tape of Comparative Example 5, the sample tapes of Examples 1 to 5 and Comparative Examples 1 to 4 are superior in still durability and weather resistance. It is understood that the characteristics of the magnetic tape can be improved by forming the protective film.

Further, comparing Examples 1 to 5 with Comparative Examples 1 to 4, it was confirmed that the relationship between the adhesion range F and the target length W was 0.5 W ≦ F ≦ 1.0 W. Dressing plate 1
It can be seen that when the protective film is formed using the thin film forming apparatus in which the opening 12 in 1 is limited, instantaneous clogs and powder falling are reduced and the shuttle characteristics are improved. Then, it was found that when the thin film forming apparatus in which the opening 12 was regulated so that F = 0.83 W was used, the magnetic tape having the most excellent shuttle characteristics could be produced. In addition, F
The sample tape of Comparative Example 1, which uses the thin film forming apparatus with 0.4 W, has few defects in characteristics, but has a problem that the film forming rate is small and the productivity is poor.

Next, the opening 12 of the deposition preventive plate 11 has F = 0.
Table 3 shows the measurement results of the sample tapes of Examples 6 to 11 in which the protective film was formed using the thin film forming apparatus which was regulated to be 83 W, but the inter-base distance d was variously different.

[0044]

[Table 3] From Table 3, it can be seen that a protective film having excellent film quality is formed in each of the sample tapes of Examples 7 to 11. However, in the sample tape of Example 6, the distance d between the substrates in the thin film forming apparatus was too small,
It was difficult to dispose the cylindrical can 6, the deposition preventive plate 11, and the target 10 without making contact with each other, and the protective film could not be formed. Also in the sample tape of Example 7, it was difficult to form a protective film in a stable discharge state because the distance d between the substrates was small. Furthermore, in the sample tape of Example 11, the distance d between the substrates is 100 mm.
If the film formation rate is not ¼ of that in the above case, the protective film having a predetermined film thickness cannot be formed, and therefore the accuracy of the traveling system for traveling the flexible support 5 cannot be ensured. The protective film was formed in this state.

FIG. 4 is a characteristic diagram showing the relationship between the distance d between the substrates and the dynamic film forming rate. The area on the right side of the broken line is an area where a stable discharge state can be obtained. From FIG. 4, it is understood that the distance d between the substrates and the film formation rate are in a substantially proportional relationship, and the film formation rate decreases as the distance d between the substrates increases. From these results,
It is understood that it is necessary to optimize not only the adhesion area F but also the inter-substrate distance d in the thin film forming apparatus.

The example in which the thin film forming apparatus according to the present invention is applied to the formation of the protective film of the magnetic recording medium has been described above.
The present invention is not limited to the above-described embodiments, but various modifications and changes are possible. For example, in a thin film forming apparatus, it is possible to change the target material and the like, and the thin film formed by the thin film forming apparatus is not limited to a protective film,
It may be a metal magnetic thin film or a conductive metal thin film.

[0047]

As is clear from the above description, in the thin film forming apparatus of the present invention, the deposition range is used to control the adhesion range of the thin film material particles, resulting in excellent uniform film thickness and durability. A thin film having excellent film quality can be formed. Therefore, when the thin film forming apparatus according to the present invention is applied to the formation of a protective film on a magnetic tape, the film thickness and film quality of the protective film can be kept uniform, and not only still characteristics and weather resistance but also shuttle characteristics are excellent. The magnetic tape can be manufactured with high yield.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration example of a thin film forming apparatus.

FIG. 2 is a cross-sectional view schematically showing a relationship among a target, an adhesion-preventing plate and a cylindrical can in the thin film forming apparatus.

FIG. 3 is a plan view of a deposition preventive plate disposed in the vicinity of a cylindrical can as seen from a lower surface.

FIG. 4 is a characteristic diagram showing a relationship between a distance between substrates and a film forming rate.

[Explanation of symbols]

 1a, b Exhaust port 2 Vacuum chamber 3 Feed roll 4 Winding roll 5 Flexible support 6 Cylindrical can 7,8 Guide roll 9 Cathode electrode 10 Target 11 Adhesion prevention plate 12 Opening

Claims (3)

[Claims] 1. A target provided on a cathode electrode is sputtered, and thin-film material particles are attached to a flexible support that runs along the peripheral surface of a cylindrical can facing above the target. In the thin film forming apparatus for forming a thin film, a deposition preventive plate for limiting the adhesion range of the thin film material particles is provided in the vicinity of the cylindrical can, and the opening of the deposition preventive plate is located at the end of the target and the end of the target. The distance from the intersection of the straight line connecting the end of the opening and the peripheral surface of the cylindrical can to the straight line vertically lowered toward the target of the cylindrical can and the target is 1/2 or more of the target length, and A thin film forming apparatus characterized by being regulated so as to be equal to or shorter than a target length. 2. The flexible support is a long film on which a metal magnetic thin film is formed.
The thin film forming apparatus described. 3. The thin film forming apparatus according to claim 2, wherein the formed thin film is a protective film made of carbon.