JPH01278437A - Coating of wire and unit therefor - Google Patents

Abstract

PURPOSE:To provide the title unit so designed that the surface of a wire is coated with a coating material brought to chemical vapor growth in the plasma flame in a plasma reaction chamber of wide space, thereby forming a coating film on the continuous wire without hampering plasma flame generation due to attachment of deposited product. CONSTITUTION:A plasma generation chamber 12 is fed, via a gas inlet pipe 17, with a plasma gas to generate a plasma flame, which is then extended to a plasma reaction chamber 13 of wide space. Thence, said plasma flame is fed with a coating raw material through a raw material pipe 21, and a wire A is passed through said flame, thus coating said wire with a coating material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for continuously forming a coating on the surface of a long filament such as an optical fiber or a metal wire.

[Conventional technology]

Metal on the surface of a long filament such as an optical fiber or metal wire,
A plasma CVD method is a method for forming a film made of metal oxide, metal nitride, carbon, or the like.

Figure 4 is this braz? CVD method (Plasma En
Hanced Chemical Vapor Dep
This figure shows an apparatus for continuously forming a coating on the striatum by different positions. Reference numeral 1 in the figure indicates a reaction chamber, and this reaction chamber 1 is a hollow cylindrical chamber made of quartz glass or the like. At both ends of this reaction chamber 1, there are vacuum chambers 2. It is provided.

The decompression chamber 2 is also a hollow cylinder made of quartz glass, etc., and the space between the decompression chamber 2.2 and the reaction chamber 1 is the striatum A.
It is partitioned off by a partition wall 4.4 having a through hole 3.3 formed therein. Also, through holes 3, 3 through which the filament is passed are formed in the end wall of the decompression chamber 2.degree. Furthermore, reaction chamber 1
A high frequency induction coil 5 is wound around the outer periphery of the high frequency induction coil 5, and this coil 5 is connected to a high frequency power source 6. Further, the reaction chamber 1 is provided with an introduction pipe 7 for introducing a plasma generating gas such as argon and a raw material gas serving as a coating material, and the decompression chamber 2.2 is provided with a decompression pipe 8 for reducing the pressure inside the chamber. .8 are provided respectively.

In order to form a coating on the filamentous body A using such a coating device, after reducing the pressure in the reaction chamber 1 and the decompression chamber 2.2, plasma generating gas and source gas are supplied to the reaction chamber 1 from the introduction pipe 7. Yes, high frequency 1! A high-frequency power source 6 applies this high-frequency current to the conductive coil 5 to cause an electrodeless discharge to generate a plasma flame in the reaction chamber 1, react the raw material gas within the plasma flame, and pass through the through holes 3... A coating is formed on the surface of the running striatum.

As the raw material gas for coating, for example, SL Cj 4
If gas is used, a film made of metallic silicon can be formed by the reaction of SLC 4 → SL + 2 (J2),
If Si C14 and 02 are supplied, 5LCI4+Oz→
A film made of silicon oxide (silica) is obtained by the reaction of 5LOz+2C1z, and when CCfzFz is used, the reaction of C(JzFz→C+C12+Fz) proceeds to obtain an amorphous or polycrystalline carbon film, and furthermore, S=C14 and NH3. and is supplied into the reaction chamber 1, 3SLCI<
+4NH3→SL3 N4 + A film made of 128C silicon nitride can be formed.

(Problem to be Solved by the Invention) However, when the above-mentioned coating device is used to
When a film is continuously formed on the striatum, the substances precipitated by the CVD reaction adhere and accumulate not only on the surface of the striatum but also on the inner wall of the reaction chamber 1, and after long-term operation, the substance deposited in the reaction chamber 1 becomes As a result, a plasma flame cannot be stably generated within the reaction chamber 1. Furthermore, when forming a film made of a conductive material such as metal or carbon, the precipitated substances adhering to the inner wall of the reaction chamber 1 act as an electromagnetic shielding layer, preventing high frequencies from penetrating into the reaction chamber 1. There is also the problem that the generation of plasma flames stops due to harmful effects.

[Means to solve the problem]

In this invention, a plasma gas is flowed at a predetermined flow rate into a plasma generation chamber to generate a plasma flame, and the plasma flame is transferred from the plasma generation chamber to a plasma reaction chamber that is connected to the plasma generation chamber and has a larger space than the plasma generation chamber. The solution was to supply the coating material into the extended plasma flame and pass it through the filament, thereby coating the filament with the produced coating material.

[Effect]

With the above configuration, the area where the coating raw material undergoes the CVD reaction is limited to the plasma reaction chamber, and the plasma reaction chamber is a sufficiently wider space than the plasma generation chamber, so that the precipitated substances can be deposited on the walls of the reaction chamber. Even if it adheres or accumulates, the generation and existence of plasma flame will not be affected. Furthermore, since no CVD reaction is performed in the plasma generation chamber, there is no deposition of precipitated substances and a plasma flame can always be generated stably.

〔Example〕

FIG. 1 shows a first example of a coating apparatus according to the present invention, and this coating apparatus 11 is roughly composed of a plasma generation chamber 12 and a plasma reaction v13.

The plasma generation chamber 12 includes a main body 14 and a high frequency induction coil 1.
5, a high frequency power source 16 and a plasma generating gas introduction pipe (plasma gas supply means) 17.

The main body 14 has a cylindrical shape made of quartz glass or the like, and one end thereof is closed at an end vi 18, and the other end is open and connected to the plasma reaction chamber 13. An inlet vibrator (wA strip insertion means) 19 for passing the filament A is provided approximately in the center of the end wall 18 of the main body 14, and the end wall 1
A plasma-generating gas introducing vibrator 17 for introducing a plasma-generating gas such as argon is provided at the edge of the main body 8 at a slight angle with respect to the axis of the main body 14 toward the reaction chamber 13 . Furthermore, a high frequency induction coil 1 is provided around the main body 14.
5 is wound, and this high frequency induction coil 15 is connected to a high frequency power source 16. Further, near the open end of the main body 14, a raw material pipe (coating raw material supply means) 21.2 for feeding raw material for the coating material into the plasma reaction chamber 13 is provided.
1 is provided toward the reaction chamber 13 at an angle with respect to the axis of the main body 14 .

Further, the plasma reaction chamber 13 is a cylindrical chamber made of quartz glass or the like and has an inner diameter approximately 2 to 5 times larger than the inner diameter of the main body 14 of the plasma generation chamber 12, and is approximately at the center of one end thereof. The plasma generation chamber 12 is opened.
The other end is closed with an end wall 22. Also, this end HX! At the center of 22, there is provided an exit vibrator (striate body insertion means) 23 for guiding out the filament A that has been coated. Furthermore, plasma reaction chamber 1
3 and a vacuum vibe 24 for maintaining the space inside the plasma generation chamber 12 at a desired pressure, and this vacuum vibe 24 is connected to an exhaust means (not shown).

Further, the inner diameters of the inlet vibrator 19 and the outlet vibrator 23 are made slightly larger than the outer diameter of the filament body A to prevent outside air from entering through these pipes 19, 23 as much as possible.

In order to form a coating on the filament body A using such a coating device, the atmosphere inside the device is exhausted from the decompression vibe 24 to reach the desired internal pressure, and then a plasma generating gas such as argon is introduced from the introduction vibe 17. The plasma is fed into the plasma generation chamber 12 at a predetermined flow rate, and the frequency number MH2 to several 10 is supplied from the high frequency power source 16.
Applying a high frequency current of MHz to the high frequency induction coil 15,
Electrodeless discharge is performed to excite the plasma generating gas within the main body 14 of the plasma generating chamber 12 to generate a plasma flame.

This plasma flame flows from the main body 14 of the plasma generation chamber 12 to the plasma reaction chamber 13 along the flow of plasma generation gas. A raw material gas for coating material is blown into the plasma flame extending to the plasma reaction chamber 13 from the raw material pipe 21, 21, and a CVD reaction is caused in the plasma flame located in the space inside the plasma reaction chamber 13. In this state, from the inlet vibrator 19 of the plasma generation chamber 12 to the plasma reaction chamber 13
When the filament A is run through the exit vibe 23 of the filament and passed through a plasma flame, a film made of metal, oxide, etc. deposited by the CVD reaction is continuously formed on the surface of the filament.

At this time, since the plasma generation gas is blown into the end wall 18 of the plasma generation chamber 12, the generated plasma flame flows from the generation chamber 12 to the reaction chamber 13, and the raw material gas for the coating material also flows into the reaction chamber. Since the plasma is blown in the direction of the plasma flame, the CVD reaction in the plasma flame occurs only in the reaction chamber 13 and does not occur in the generation chamber 12. Therefore, precipitated substances do not adhere or accumulate on the inner wall of the plasma generation chamber 12. In addition, since the internal volume of the plasma reaction chamber 13 is sufficiently large compared to the volume of the plasma flame itself, even if precipitated substances other than those that adhere to the filament A and become a film are present in the reaction chamber 13, Even if it adheres to the inner wall, the stability of the plasma flame is not threatened by this adherent. Therefore, the device can be operated continuously for a long period of time, and coatings can be continuously and stably formed on extremely long filaments.

FIG. 2 shows a second example of the coating device of the present invention. This device uses a nozzle-like member 25 as the plasma generation chamber 12, and this nozzle-like member 25 is placed inside a rectangular cavity resonator 26. The microwave from the magnetron 27 provided on the starting end side of the cavity resonator 26 is transmitted to the directional coupler 28.
The wave is guided to the terminal end of the cavity resonator 26 through the plasma generator 26, and a plasma flame is generated within the nozzle-shaped member 25 which becomes the plasma generation chamber 12. The nozzle-shaped member 25
is made of quartz glass or the like, and the length in the axial direction of the portion existing inside the cavity resonator 26 corresponds to approximately 1/4 wavelength of the microwave.

Furthermore, a movable plunger 29 is provided at the end of the cavity resonator 26, so that the state of alignment with the plasma flame can be varied. Further, a through hole 31 through which the filament body A passes is formed in the base end portion 30 of the nozzle-like member 25, and this n
A plasma generating gas introduction vibe 17 is provided on the side of the through hole 31 .

Further, the tip of the nozzle-like member 25 extends to a communication hole 32 formed in the cavity resonator 26 and communicating with the plasma reaction chamber 13 . Furthermore, two raw material vibrators 21, 21 are provided passing through the wall of the plasma reaction chamber 13, and the Suita portions of these tips are inclined in the running direction of the filament body A and reach close to the communication hole 31. It is extending.

In the coating device of this example, the microwave oscillated by the magnetron 27 is emitted from the antenna 33, guided through the directional coupler 28 into the nozzle-shaped member 25, excites the plasma generating gas inside the nozzle-shaped member 25, and generates a plasma. Generates flame. This plasma flame passes from the tip of the nozzle-shaped member 25, which is the plasma generation chamber 12, through the communication hole 32 and into the plasma reaction chamber 1.
It is radiated towards 3. Raw material gas is blown into this plasma flame from the raw material vibrator 21.21, and a CVD reaction occurs. In this state, if the filament A is run in the opposite direction from the nozzle-shaped member 25 of the plasma generation chamber 12 to the plasma reaction chamber 13 and passed through the plasma flame, a film will be continuously formed on the surface of the filament. be done.

Further, since the internal volume of the plasma reaction chamber 13 is sufficiently large as in the previous example, even if precipitated substances adhere to or accumulate on the inner wall of the plasma reaction chamber 13, the generation of the plasma flame will not be inhibited at all.

Note that a through hole is formed in the body of the cavity resonator 26 in order to arrange the nozzle-like member 25, but as shown in FIG. If the dimensions of the cavity resonance WA 26 are set so that they are maximum at the position of the n through-holes, and the boundary conditions are determined, the through-holes will hardly have an adverse effect on the state of the microwave. Note that the arrow lines in FIG. 3 indicate lines of electric force.

Further, as the filament A in this invention, glass Si
Examples include optical fibers, metal wires, superconducting wires, those whose surfaces are coated with a primary coating, those wires twisted together, and composites with other wires.

Further, the raw material for the coating material is not limited to gaseous materials, but may be liquid or powdery materials.

[Experiment example]

Using the coating apparatus shown in FIG. 2, the surface of a quartz optical fiber was coated with amorphous carbon.

The inner dimensions of the rectangular cavity resonator 26 are 85mm x 45+w,
The nozzle-shaped member 25 made of quartz glass had an inner diameter of 10 mm and a length of 45 am. On the other hand, the plasma reaction chamber 13 was made of hard glass, and had an inner diameter of 250 am and a length of 250 mm. Frequency 2450MHz from magnetron 27, output 6
A microwave of 00 W was emitted, 15 SLM of argon was supplied as a plasma generation gas, the pressure inside the plasma reaction chamber 13 was maintained at 70 Torr, and 3 SLM of CCl2F2 (Freon 12) was supplied as a coating material gas. I reacted with In this state, the outer diameter is 125μ
When a quartz-based optical fiber of 1.5 m is run at a linear speed of 10 m/min, an amorphous carbon film with a thickness of 80 nIl is continuously formed on the optical fiber, and the coating speed is 12 m/min.
It was n11/min.

When an optical fiber provided with an amorphous carbon coating was left in a 100% hydrogen atmosphere at 1 atm for 100 hours, no diffusion of hydrogen molecules into the optical fiber was observed.

Further, the coating apparatus was continuously operated for 10 hours to form a coating on an optical fiber having an extension of 6-, but the plasma generation was always stable and the operation was good.

〔Effect of the invention〕

As explained above, the present invention generates a plasma flame by flowing plasma gas at a predetermined flow rate into a plasma generation chamber, and communicates the plasma flame with the plasma generation chamber, which has a space larger than the plasma generation chamber. The plasma flame is extended to the plasma reaction chamber, the coating material is supplied into this extended plasma flame, and the coating material produced by passing through the filament is coated on the filament. Since the CVD reaction is carried out in a plasma reaction chamber with a wide space, the generation of plasma flame is not inhibited even if precipitated substances are attached or deposited due to the reaction, and long filaments can be produced stably for a long time. A coating can be formed on the body.

[Brief explanation of the drawing]

1 and 2 are both schematic configuration diagrams showing an example of the coating device of the present invention, FIG. 3 is a diagram showing the electric field distribution in the cavity resonator of FIG. 2, and FIG. 4 is a diagram showing the conventional coating device. FIG. 11... Coating device, 12... Plasma generation chamber, 13
. . . Plasma reaction chamber, 14 . . . Main body, 15 .
4... Decompression vibrator, 25... Nozzle-shaped member, 26...
...Cavity resonator, 27...Magnetron.

Claims (2)

[Claims] (1) Plasma gas is flowed at a predetermined flow rate into the plasma generation chamber to generate a plasma flame, and the plasma flame is extended from the plasma generation chamber to the plasma reaction chamber, which is in communication with the plasma generation chamber and has a larger space than the plasma generation chamber. A method for coating a filamentous body, characterized by supplying a coating material into the extended plasma flame and passing the coating material through the filament body to coat the generated coating material on the filament body. (2) a plasma generation chamber; a plasma gas supply means for flowing plasma gas into the plasma generation chamber at a predetermined flow rate; a plasma reaction chamber that communicates with the plasma generation chamber and has a space wider than the plasma generation chamber; A coating apparatus for a filamentous body, comprising a coating raw material supplying means for supplying a coating raw material to a plasma reaction chamber, and a filament insertion means for passing the filamentous body through the plasma reaction chamber.