JP2000017440A - Plasma assisted cvd deposition apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma assisted CVD deposition apparatus capable of adequately bringing a raw material film and a cooling can roll into tight contact with each other and executing deposition without the occurrence of trouble, such as variation in film thickness, even when the raw material film gives rise to thermal deformation. SOLUTION: The raw material tape T is travelably wound around a take-up roll 44 through the cooling can roll 64 from an un-winding roll 42 in a processing chamber 22 of a vacuum vessel 20. A reaction tube 60 which generates a plasma is disposed to face the raw material tape T wound around the cooling can roll 64. The traveling route of the raw material tape T is provided with an electrifier 80 which electrifies a film substrate negative by irradiating the film substrate of the raw material tape T with an electron beam on the upstream side of the cooling can roll 64. In addition, the cooling can roll 64 is constituted by forming an insulating layer on the peripheral surface of the roll body made of a conductive metal. The roll body is connected to the negative terminal of a DC bias power source 104 and negative voltage is impressed to the roll body to electrify the surface of the insulating layer positive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape or LS
The present invention relates to a plasma CVD film forming apparatus used for manufacturing I.

[0002]

2. Description of the Related Art Magnetic tapes such as audio tapes and video tapes are formed by forming a magnetic layer (conductive primary thin film) of a metal magnetic material such as cobalt or nickel on a film base of an insulating resin such as polyethylene terephthalate. A protective layer (secondary thin film) such as a plasma polymerized film is formed on the magnetic layer. In general, the protective layer is formed using a plasma CVD film forming apparatus, that is, a raw material film in which a conductive primary thin film is formed on a film substrate is caused to run along a cooling can roll. Then, a secondary thin film is formed by vapor deposition using a plasma CVD method.

However, the above-described plasma CVD film forming apparatus has a disadvantage that the adhesion to the can roll is easily damaged due to thermal deformation of the film substrate and the like, and it is difficult to form a thin film stably. . Therefore, conventionally, various plasma CVD film forming apparatuses have been proposed in which the adhesion between the peripheral surface of the can roll and the film substrate is improved, and this kind of plasma CVD film forming apparatus is described in Japanese Patent Application Laid-Open No. 2-239428. Things are known.

[0004] The above-mentioned Japanese Patent Application Laid-Open No. 2-239428 describes a plasma CVD film forming apparatus for irradiating a film substrate with an electron beam and thereafter bringing the film substrate into contact with a cooling can roll to form a film. . This film forming apparatus irradiates a raw material film with an electron beam to negatively charge the raw material film, induces a positive charge on the peripheral surface of the can roll, and generates a raw material by electric attraction generated between the raw film and the can roll. The film is brought into close contact with the peripheral surface of the can roll.

[0005]

However, the plasma CV described in the above-mentioned Japanese Patent Application Laid-Open No. 2-239428 has been proposed.
In the case of the D film forming apparatus, a positive charge is not stably induced on the peripheral surface of the can roll, and the electric attraction becomes unstable. There is a problem that charging on the contact surface with the can roll is unstable. In particular, the latter problem is considered to be remarkable in the case of using a raw material film in which a metal thin film is formed on a film substrate, that is, in a DC plasma CVD apparatus, and a solution to the problem is strongly desired. The present invention has been made in view of the above problems, and has as its object to provide a plasma CVD film forming apparatus capable of stably obtaining an appropriate electric attraction between a raw material film and a can roll.

[0006]

In order to achieve the above object, the present invention comprises a cooling can roll and an electrode arranged in a vacuum chamber capable of supplying and reducing the pressure of a raw material gas, and a conductive primary thin film on one surface of a base film. Applying a voltage to the electrode while running the raw material film on which is formed along the peripheral surface of the cooling can roll facing the electrode to form a secondary thin film on the conductive primary thin film of the raw material film Plasma C
In the VD film forming apparatus, a roll charging means for charging the cooling can roll to one of positive and negative, and a cooling roll provided upstream of the raw material film in the running direction with respect to the cooling can roll, and A film charging means for charging to a different polarity from the can roll is provided.

In the plasma CVD film forming apparatus according to the present invention, the cooling can roll is charged to one of the positive and negative sides, and the film substrate of the raw material film is charged to the polarity opposite to that of the cooling can roll. For this reason, a proper electric attraction is obtained between the cooling can roll and the raw material film, and the film base of the raw material film can be brought into close contact with the peripheral surface of the cooling can roll with a proper adhesion force. A thin film can be formed stably.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a plasma CVD film forming apparatus according to an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of the plasma CVD film forming apparatus, and FIG. Perspective view schematically showing a main part,
FIG. 3 is a sectional view schematically showing another main part of the plasma CVD film forming apparatus.

In FIG. 1, reference numeral 20 denotes a vacuum chamber defining a processing chamber 22 therein. The vacuum chamber 20 is made of stainless steel or the like, and the wall of the chamber is connected to a DC high-voltage power supply 102 to have a predetermined positive potential. Will be retained. In the processing chamber 22 of the vacuum chamber 20, an unwinding roll 42 and a take-up roll 44 are provided at an upper portion at a horizontal interval, a cooling can roll 64 is provided at a central portion, and the unwinding roll 42 and the take-up roll 44 are provided. And a pair of pass rolls 4 between
6A, 46B, 48A, 48B are rotatably mounted, a charger (film charging means, electron beam irradiator) 80 is provided between the unwinding roll 42 and the pass roll 46A, and a reaction tube 60 is provided below. .

The material film T is wound around the unwinding roll 42, and the winding roll 44 is connected to a rotation driving mechanism and driven to rotate. Then, from the unwinding roll 42 to the pass roll 4
The raw film T is rotatably wound around the take-up roll 44 via the cooling rolls 6A and 46B, the cooling can roll 64 and the pass rolls 48A and 48B. Although not shown, the raw material film T is formed by forming a magnetic layer (conductive primary thin film) on one surface of a film base such as polyethylene terephthalate, and wound in a state where the film base is in contact with the peripheral surface of the cooling can roll 64. Can be hung.

[0011] Pass rolls 46A, 46B, 48A, 48
B contacts (rolls) with the magnetic layer forming surface of the raw material film T
And guide the run. And one pass roll 46B
Have conductivity and are electrically grounded. The conductive pass roll 46B comes into contact with the magnetic layer of the raw material film T and maintains the magnetic layer at a constant potential. In addition, pass roll 4
6B can be connected to a bias power supply and maintained at a predetermined negative potential, or can be made of a semiconductor material or the like having a predetermined resistance value.

As shown in FIG. 2, the charger 80 has an electron gun 84 housed in a housing 82 having an opening on the side of the raw material film T. The housing 82 is installed with a predetermined gap δ (usually 2 mm or less) from the film substrate surface of the raw material film T, and the inner surface of the housing 82 is electrically grounded. The electron gun 84 is a well-known one, for example, “Hol
low Cathode Neutralizer "
(Trade name, manufactured by Ion Tech Co., Ltd.) is used, and the electron beam is irradiated to the fan-shaped area B extending in the direction perpendicular to the running direction of the raw material film T, that is, over the entire width.

As shown in FIG. 3, the cooling can roll 64 is formed by forming an insulating layer 64b on the peripheral surface of a cylindrical roll body 64a integrally having shaft portions 64c on both sides. It is rotatably supported via an insulating bearing 68 made of bakelite or the like. Roll body 64
a is made of a conductive metal such as stainless steel, is connected to the DC bias power supply 104, and holds a predetermined negative potential;
For example, a voltage of about -300 V or less and about -1000 V or more is applied. The insulating layer 64b is formed by coating an insulating material such as ceramic to a thickness of about 0.5 mm to 1.0 mm. This insulating layer 64b is formed of a roll body 64.
Since a negative voltage is applied to a, the surface is positively charged by electrostatic induction. The cooling can roll 64
Is driven to rotate by a rotation driving mechanism or the like, and cooling water or the like is introduced therein. However, since these structures are well-known, description thereof is omitted.

The reaction tube 60 has an electrode 65 in a tube main body 62 having a cylindrical opening on the cooling can roll 64 side.
Further, a gas introduction tube 66 is opened at a lower portion of the tube main body 62. The electrode 65 is connected to the positive terminal of the DC high-voltage power supply 102, and the gas introduction tube 66 communicates with a reaction gas supply source (not shown) to introduce a reaction gas into the tube main body 62. The reaction tube 60 is well known, and a detailed description is omitted.

In the present embodiment, the unwinding roll 42
The raw material film T fed out of the raw material film travels along the peripheral surface of the cooling can roll 64 and is wound on the take-up reel 44, and the protective layer ( (Secondary thin film) and the like. That is,
As is well known, the reaction gas introduced into the reaction tube 60 becomes plasma when passing through the electrode 65, and the molecules in the raw material gas are decomposed into positive radicals.
The protective film is formed by adhering to the surface of the magnetic layer of the raw material film T electrically grounded via 6B.

Here, during the formation of the protective film, that is, when the raw material film T travels, the raw material film T is irradiated with an electron beam by the charger 80 between the unwinding roll 42 and the pass roll 46A, and becomes negative. In addition, the cooling can roll 64 is charged, and a negative voltage is applied to the roll body 64a, so that the surface of the insulating layer 64b is charged positively. Therefore, an appropriate electric attraction is generated between the film substrate of the raw material film T and the surface of the insulating layer 64b of the cooling can roll 64, and the insulating film of the cooling can roll 64 and the film substrate surface of the raw material film T are generated. The 64b surface can be brought into close contact with an appropriate contact force. Accordingly, even when thermal deformation or the like occurs in the raw material film T, film formation can be appropriately performed, and occurrence of unevenness in film thickness can be prevented.

FIGS. 4 and 5 show a plasma CVD film forming apparatus according to another embodiment of the present invention. FIG. 4 is a schematic diagram showing the entire structure, and FIG. FIG. 5B is a schematic diagram in which a part of FIG. 5A is enlarged. Note that the same parts as those in the above-described embodiment are denoted by the same reference numerals (reference numerals), and description thereof will be omitted.

In this embodiment, the pass rolls 46A, 46
A charging roll 88 that comes into contact with the surface of the film substrate of the raw material film T is provided in the tape running path between B and B. The charging roll 88 is made of a conductive material such as stainless steel and is connected to a positive terminal of a
A positive voltage of about V or more and about 1000 V or less is applied. The charging roll 88 contacts (rolls) with the film substrate surface of the running raw material film T, and positively charges the film substrate surface.

The cooling can roll 64 is shown in FIG.
As shown in (a) and (b), a first insulating layer 64e, a conductive layer 64f, and a second insulating layer 64g are formed on the peripheral surface of the roll body 64a. The first insulating layer 64e is formed by coating an insulating material such as ceramic to a thickness of about 0.5 mm, and covers the entire peripheral surface of the roll body 64a.
The second insulating layer 64g is formed by coating an insulating material such as a ceramic to a thickness of about 0.5 mm similarly to the first insulating layer 64e, and covers the surface of the conductive layer 64f excluding the side portions. The surface of the second insulating layer 64g is negatively charged by electrostatic induction when a positive voltage is applied to the conductive layer 64f. The bearing 68 can be used regardless of conductivity or insulation.

The conductive layer 64f is formed by coating a conductive material such as aluminum or silver to a thickness of about 0.3 mm by thermal spraying or the like. The conductive layer 64f is provided with a slip ring 64h on the exposed side surface, and is connected to a DC bias power supply 108 via a shoe 64i that is slidably fitted to the slip ring 64h. A positive voltage of 300 V or more and 1000 V or less is applied to the conductive layer 64f by the DC bias power supply 108.

In the present embodiment, the raw material film T
Is positively charged by the charging roll 88, and the surface of the outermost second insulating layer 64g of the cooling can roll 64 is negatively charged by the positive voltage applied to the conductive layer 64f. Therefore, similarly to the above-described embodiment, an appropriate electric attraction is generated between the film substrate of the raw material film T and the surface of the second insulating layer 64g of the cooling can roll 64, and the raw material film T The film substrate surface can be brought into close contact with the cooling can roll 64 with an appropriate adhesion force, and even when thermal deformation or the like occurs in the raw material film T, film formation can be appropriately performed, and unevenness in film thickness can be prevented.

In the above-described embodiment, the surface of the cooling roll 64 can be negatively charged by adopting a similar structure and inverting the polarity of the applied voltage. That is, as shown in FIG. 6, the cooling can roll 64 is also insulated by forming a single insulating layer 64b on the surface of the conductive roll main body 64a and connecting the roll main body 64a to the positive terminal of the DC bias power supply 104. The surface of the layer 64b can be negatively charged.

In each of the above embodiments,
Although a DC plasma CVD film forming apparatus is illustrated, the present invention can also be applied to a high frequency plasma CVD film forming apparatus.

[0024]

As described above, according to the plasma CVD film forming apparatus of the present invention, the surface of the can roll is charged to one of the positive and negative sides, and the film base of the film material is charged to the other of the positive and negative sides. Proper electric attraction is obtained between the film raw material and the cooling can roll, the adhesion between the film raw material and the cooling can roll can be improved, and the film can be properly formed even when the film raw material is deformed by heat. It is possible to prevent the occurrence of unevenness in film thickness.

[Brief description of the drawings]

FIG. 1 shows a plasma CV according to one embodiment of the present invention.
1 is an overall schematic configuration diagram illustrating a D film forming apparatus.

FIG. 2 is an enlarged schematic perspective view showing a main part of the plasma CVD film forming apparatus.

FIG. 3 is an enlarged schematic cross-sectional view showing another main part of the plasma CVD film forming apparatus.

FIG. 4 is a plasma CV according to another embodiment of the present invention.
1 is an overall schematic configuration diagram illustrating a D film forming apparatus.

FIGS. 5A and 5B schematically show a main part of the plasma CVD film forming apparatus, wherein FIG. 5A is a cross-sectional view and FIG.

FIG. 6 is a schematic cross-sectional view showing another embodiment of the main part of the plasma CVD film forming apparatus.

[Explanation of symbols]

20 vacuum chamber, 22 processing chamber, 42 unwinding roll, 44 winding roll, 46A, 46B, 48A, 4
8B: pass roll, 60: reaction tube, 62: tube body, 65: electrode, 64: cooling can roll, 64
a roll body, 64b insulating layer, 64e first
An insulating layer, 64f conductive layer, 64g second insulating layer, 66 gas introduction tube, 80 charger (film charging means, electron beam irradiator), 82 housing, 84
... Electron gun, 102 DC high voltage power supply, 106 DC bias power supply, 108 DC bias power supply, T raw material film.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryoichi Hiratsuka 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 4K030 BB12 CA07 CA12 FA03 GA14 HA13 KA20 KA30 LA20 5D112 AA02 AA05 AA07 AA22 FA10 FB21 FB25 FB26

Claims (8)

[Claims] 1. A cooling can roll and an electrode are arranged in a vacuum chamber capable of supplying and depressurizing a raw material gas, and a raw material film having a conductive primary thin film formed on one surface of a base film is used as an electrode of the cooling can roll. A voltage is applied to the electrode while running along the peripheral surface opposite to the above, and a plasma CVD film forming apparatus for forming a secondary thin film on the conductive primary thin film of the raw material film, wherein the cooling can roll is Or a roll charging means for charging the negative one, a film charging means provided on the upstream side in the running direction of the raw material film from the cooling can roll, and charging the film substrate to a polarity different from that of the cooling can roll, A plasma CVD film forming apparatus comprising: 2. The insulating roll according to claim 1, wherein the cooling can roll has an insulating coating layer formed on a peripheral surface of a roll body made of a conductive metal, and the roll charging means insulates the roll body so as to rotatably support the roll body. 2. The plasma CVD film forming apparatus according to claim 1, further comprising a bearing, and a DC bias power supply for applying a bias voltage to the roll body. 3. The method according to claim 2, wherein the bias voltage is 300 V or more and 100 or more.
0V or less positive voltage or -300V or less -1000
3. The plasma CVD film forming apparatus according to claim 2, wherein the negative voltage is not less than V. 4. The cooling can roll has an insulating first coating layer on the peripheral surface of a conductive metal roll main body, and a conductive second conductive layer.
2. The plasma CVD method according to claim 1, wherein a coating layer and an insulating third coating layer are formed, and said roll charging means includes a DC bias power supply for applying a bias voltage to said second coating layer. Membrane equipment. 5. The method according to claim 1, wherein the bias voltage is 300 V or more and 100 or more.
0V or less positive voltage or -300V or less -1000
The plasma CVD film forming apparatus according to claim 4, wherein the negative voltage is not less than V. 6. The plasma CVD film forming apparatus according to claim 1, wherein said film charging means comprises an electron beam irradiator for irradiating the film base of said raw material film with an electron beam. 7. A conductive charging roller provided so that the film charging means can contact the film base upstream of the cooling can roll in a traveling path of the raw material film, and a bias voltage is applied to the charging roller. 2. The plasma CVD film forming apparatus according to claim 1, further comprising: a DC bias power supply for applying a voltage. 8. The method according to claim 1, wherein the bias voltage is 100 V or more and 100 or more.
0V or less positive voltage or -100V or less -1000
8. The plasma CVD film forming apparatus according to claim 7, wherein the negative voltage is not less than V.