JPH0892735A - Vacuum deposition method - Google Patents

Abstract

(57) [Abstract] [Purpose] A vapor deposition substrate, a metal body as an anode, and a long metal rod as a cathode are arranged in a vacuum container, and a DC voltage is applied to the anode and the cathode. Then, arc discharge is performed to evaporate the low melting point metal from the cathode,
In a vacuum vapor deposition method for forming a metal vapor deposition film on the surface of a substrate to be vapor-deposited, deformation or melting of the cathode tip portion and deformation of the cathode itself are prevented, and stable arc discharge enables efficient vapor deposition for a long period of time. [Configuration] As a cathode 40, a refractory metal core material 41,
Arc discharge is performed using a metal rod made of a low-melting-point metal coating material 42 that covers the side peripheral surfaces of the core material 41 other than the tip portion 41A. [Effect] Since it has a high-melting-point metal core material, it has high rigidity and strength and does not deform. Since the high melting point metal core material is exposed at the tip, it does not deform or melt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum vapor deposition method, and in particular, a vapor deposition base material, a metal body as an anode, and a long evaporative metal body as a cathode are arranged in a vacuum container. Then, a DC voltage is applied to the anode and the cathode to perform arc discharge, and a metal is evaporated from the cathode to form a metal vapor deposition film on the surface of the substrate to be vapor deposited. The present invention also relates to a vacuum vapor deposition method using an evaporative metal body made of a low melting point metal, which prevents deformation or melting of the cathode tip portion and enables efficient vapor deposition for a long time by stable arc discharge.

[0002]

2. Description of the Related Art Conventionally, as a method for forming a metal coating on a synthetic fiber sheet such as a woven or non-woven fabric of synthetic fibers, a chemical plating (commonly called electroless plating) method is generally employed. In this case, a synthetic fiber sheet made of a woven or non-woven fabric of synthetic fibers is supplied to the electroless plating step as a wound continuous sheet, and a metal coating is mainly formed on both sides of the sheet at the same time. Before the electroless plating step, usually, a step of subjecting the synthetic fiber continuous sheet to an alkaline degreasing treatment, a neutralizing treatment, and a catalyzing treatment is provided in advance.

The electroless plating bath is composed of metal ions to be plated, a reducing agent for the metal ions and other auxiliaries, but the metal ion concentration is lowered during the plating operation, so that it is necessary to replenish it. And control the bath composition,
Bath temperature control is important. However, if replenishment is repeatedly used after the bath is built, the bath composition will be out of balance, and therefore it is necessary to discard the plating bath at a certain point and rebuild the bath. For this reason, waste liquid treatment costs are required.
There are drawbacks such as not being preferable in terms of safety and health.

Moreover, it is technically difficult to obtain a high-purity metal film by the method of forming a metal film by electroless plating.

The present applicant has solved the above-mentioned conventional problems,
A film such as a metal film can be easily and efficiently formed on the surface of a synthetic fiber sheet as a film with good adhesion and uniform and high purity without causing pollution and safety and health problems. As a method for forming a film on a synthetic fiber sheet, a metal body is placed as an anode and a vaporizable metal body is placed as a cathode in a vacuum vessel, and a DC voltage is applied to the anode and the cathode to perform arc discharge. Due to
A method for forming a film of evaporated metal on the surface of the synthetic fiber sheet was proposed, and a patent application was previously filed (Japanese Patent Application No.
195397. Hereinafter referred to as "first application". ).

FIG. 3 is a system diagram showing a low temperature arc vapor deposition apparatus used in the method of this prior application. In this device,
An anode 2 made of, for example, a carbon steel rod is arranged in the upper portion of the vacuum container 1, and a cathode 3 made of a round rod of an evaporative metal body is arranged in the lower portion. The anode 2 is configured to mechanically move in the vertical direction and repeatedly come into contact with and separate from the cathode 3.

An object to be coated 4 is arranged in parallel with the cathode 3 in the vacuum container 1. The anode 2 and the cathode 3 are connected to a power supply device 13 via conductive wires 21 and 22, respectively, and the power supply device 13 is configured to apply a predetermined voltage according to an instruction from a control panel 14.

The vacuum container 1 is connected to the oil diffusion pump 8 via a main valve 10 and a baffle 9 by a pipe 23. The vacuum container 1 in the pipe 23 and the main valve 9A are connected to each other.
A pipe 24 including a vent valve 7 and a roughing valve 6 is connected to the oil rotary pump 5. Oil rotary pump 5 of this pipe 24
The rough suction valve 6 is connected to the suction port of the oil diffusion pump 8 by a pipe 25 including the upstream valve 11.

Reference numeral 12 is a refrigerator for cooling and recovering the evaporated oil for recirculation, which is connected to the baffle 9 by a pipe 26. Reference numeral 15 is a gas cylinder of oxygen, nitrogen or lower hydrocarbon gas, which is connected to the vacuum container 1 by a pipe 27 equipped with a valve 16, a flow meter 17, and a pressure reducing control valve 18.

In order to form a metal vapor deposition film on the object 4 to be coated by the low temperature arc vapor deposition apparatus thus constructed, first, the oil rotary pump 5 is operated to roughly pull the inside of the vacuum vessel 1 and then the oil is evaporated. The diffusion pump 8 is operated to bring the inside of the vacuum container 1 to a predetermined vacuum degree (10 ⁻³ to 10 ⁻⁵ Torr). Then, a DC voltage is applied between the anode 2 and the cathode 3 to perform arc discharge and vapor deposition of metal. In the figure, 30 is an anode driving unit, and 31 is a cathode holding unit.

In the method of the above-mentioned prior application, a round bar made of an evaporative metal is used for the cathode, and metal vapor is blown radially from the entire circumference of the round bar electrode to perform vapor deposition on the object to be coated. As compared with the case of using the plate electrode, there is an advantage that the low temperature vapor deposition is possible with high productivity.

[0012]

In the method of the above-mentioned prior application, lead (Pb: melting point 328 ° C.) is used as the cathode.
When an evaporative metal body made of a low melting point metal such as the above is used, the following problems occur.

That is, the tip of the cathode is processed into a hemispherical shape or a truncated cone shape so that the arc can be easily transferred from the anode. By repeatedly contacting the tip with the anode, the cathode material is changed. Since it is soft and has a low melting point, the tip of the cathode is deformed or melted. In a remarkable case, the length of the cathode is shortened by about 10 cm, which exceeds the contact control range with the anode, and the arc running cannot be continued.

Further, when the length of the cathode is made longer than usual, or when the diameter of the cathode is made thinner than usual, or the mounting position is changed from the normal vertical type (vertical standing) to, for example, the sideways ( In the case of (horizontal arrangement), the low-melting-point metal lacks rigidity and strength, and the cathode is bent, so that the facing position of the metal with respect to the anode is deviated, and arc running cannot be continued.

The present invention solves the above-mentioned problems of the prior application, and arranges a substrate to be vapor-deposited, a metal body as an anode, and a long metal rod as a cathode in a vacuum container. A vacuum deposition for forming a metal deposition film of the low melting point metal on the surface of the deposition target substrate by evaporating the low melting point metal from the cathode by applying a DC voltage to the cathode and the cathode to perform arc discharge. Another object of the present invention is to provide a vacuum vapor deposition method that prevents deformation or melting of the cathode tip portion, enhances the rigidity and strength of the cathode, and performs efficient vapor deposition for a long period of time by stable arc discharge.

[0016]

According to a first aspect of the present invention, there is provided a vacuum vapor deposition method in which a vapor-deposited substrate is placed in a vacuum container, and a metal body as an anode and a long metal rod as a cathode are provided for each electrode. Of the low melting point metal by evaporating the low melting point metal from the cathode by applying a direct current voltage to the anode and the cathode to perform arc discharge and evaporating the low melting point metal from the cathode. In a vacuum vapor deposition method for forming a metal vapor deposition film made of a metal, as the cathode, a core material made of a metal having a melting point higher than that of the low melting point metal, and a low surface covering a side peripheral surface other than the tip end portion of the core material. A metal rod provided with a coating material made of a melting point metal is used.

According to a second aspect of the present invention, in the vacuum vapor deposition method according to the first aspect, a shielding plate is provided so as to partition the cathode surrounding region of the tip portion of the metal rod from the cathode surrounding region provided with the coating material. It is characterized by

[0018]

The metal rod of the cathode has a core material made of a metal having a melting point higher than that of the low melting point metal (hereinafter referred to as "high melting point metal"), so that the metal rod has sufficient rigidity and strength. Even if the metal rod is long or has a small diameter, and is arranged in the horizontal direction, it does not deform. Further, since the tip of the metal rod is exposed at the tip of the metal rod, the tip is not deformed or melted by repeated contact with the anode. Therefore, stable arc discharge can be performed over a long period of time, and efficient vapor deposition can be performed. In addition, since the metal vapor is smoothly evaporated from the low-melting-point metal coating material provided on the side peripheral surface other than the tip portion of the core material,
There is no problem in the formation efficiency of the low melting point metal vapor deposition film.

According to the second aspect, during the arc discharge, even when the metal vapor is scattered from the tip of the high melting point metal core material exposed to the outside without being covered with the low melting point metal,
The shielding plate prevents it from adhering to the surface of the substrate to be vapor-deposited, and can form a high-quality metal vapor-deposition film with high purity and free from impurities.

[0020]

Embodiments of the vacuum vapor deposition method of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a schematic structure of a main part of a low-temperature arc vapor deposition apparatus suitable for carrying out the vacuum vapor deposition method of the present invention. In FIG. 1, a member having the same function as the member shown in FIG. Are given the same reference numerals. FIG. 2 is an enlarged view of the cathode shown in FIG.

In the method of this embodiment, as the cathode 40, a core material 41 made of a high melting point metal, a tip end portion 41A of the core material 41 and a base end portion 4 held by the cathode holding portion 31 are used.
A metal rod provided with a low-melting-point metal coating material 42 that covers the side peripheral surfaces other than 1B is used. This metal rod itself has the same shape as the conventional metal rod for cathode, and as shown in the figure, in the normal case,
A round bar having a substantially hemispherical tip or a truncated cone shape is adopted.

In the present invention, the high melting point metal constituting the core material of such a metal rod is not particularly limited as long as it has a high melting point and high rigidity and strength.
Iron (melting point approx. 1530 ℃), stainless alloy (melting point approx. 15
(00 ° C.) and the like are generally used. In particular, general structural steel materials such as SS400 (melting point of about 1500 ° C.) are effective because they are easy and inexpensive to process, have a high melting point, and have high strength.

In the present invention, the length of the tip portion of the core material to be exposed without being coated with the low melting point metal coating material (see FIG. 3).
H) of No. varies depending on the size of the cathode, the arc discharge conditions, and the material of the cathode, but in the normal case, it is preferably about 30 to 50 mm. If this height is less than 30 mm, a sufficient protective effect cannot be obtained, and if it exceeds 50 mm, the effective deposition area of the cathode is reduced, which is not preferable.

Further, the thickness of the low-melting-point metal coating material of the metal rod (W _{1 in} FIG. 2) and the thickness of the core material in the portion covered with the low-melting-point metal coating material (W _{2 in} FIG. ₂ ). W ₁ = 1 respectively
It is preferable that 0 to 20 mm and W ₂ = 10 to 20 mm. That is, when W ₁ exceeds 20 mm, the thickness of the core material has to be relatively thinned, and the rigidity and strength of the cathode are insufficient. When W ₁ is less than 10 mm, the amount of the low melting point metal is too small and the deposition duration time becomes short. Further, if W ₂ exceeds 20 mm, the thickness of the low melting point metal coating material has to be relatively thin, and the duration of vapor deposition becomes short, and if it is less than 10 mm, the rigidity and strength of the cathode are insufficient.

By the way, the cathode 4 having such a core material
When the arc discharge is performed using 0, the tip portion 41 of the cathode 40 is
Evaporated particles of the high melting point metal may scatter from A, and these may adhere to the object to be coated 4 to reduce the purity of the deposited film formed.

In this embodiment, in order to solve such a problem, the tip portion 41A made of a refractory metal of the cathode 40 is used.
A disk-shaped shielding plate 43 having an opening 43A in the center is provided immediately below the tip portion 41A so as to partition the cathode surrounding area A from the cathode surrounding area B on the base end side of the tip portion 41A. There is. Even if the vaporized particles of the refractory metal are scattered from the tip portion 41A by the shielding plate 43, this will cause
It is possible to prevent the high-purity vapor-deposited film made of a low melting point metal that constitutes the coating material 42 of the cathode 40 from being formed on the surface 4A to be coated of the object 4 to be coated.

As a material for forming the shielding plate, a lightweight and insulating material is preferable, and for example, FRP, alumina and the like are preferable. In the usual case, it is preferable that the shielding plate is in the shape of a disk having an outer diameter smaller than the inner diameter of the object to be coated by about 10 mm in which an opening having a diameter larger than the outer diameter of the cathode by about 10 mm is formed. , Such a shielding plate
5 to 10 m from the base end side of the tip of the cathode (41a in FIG. 3)
It is preferably provided at a position of about m from the covering material.

According to the present invention as described above, a metal vapor deposition film can be formed on the surface 4A to be coated of the object 4 to be coated in the same manner as in the method of the above-mentioned prior application. Prevents deformation or melting of the tip, holds the cathode itself stable, and performs stable arc discharge for a long time,
Efficient vapor deposition can be performed.

The low melting point metal to which the present invention is applied has a melting point of about 500 ° C. or lower, for example, lead (melting point 328 ° C.), tin (melting point 231 ° C.), indium (melting point 156 ° C.). , A metal such as zinc (melting point 419 ° C.), or a low melting point alloy containing these. In order to manufacture a cathode with the high-melting-point metal core material and the low-melting-point metal coating material, a fusion molding method, or a method of winding the low-melting-point metal coating material around the high-melting-point metal core material is adopted. be able to.

By using a water-cooled structure for the cathode,
The duration of the arc can be further extended.

On the other hand, in the present invention, as the anode, in addition to carbon steel, stainless steel, molybdenum metal or the like can be used. When vapor-depositing a metal oxide, a metal nitride, or a metal carbide of a vapor low-melting-point metal that constitutes the cathode, in FIG. 3, oxygen gas, nitrogen gas, or a lower gas such as acetylene or methane is supplied from the gas cylinder 15 in FIG. The hydrocarbon gas may be introduced into the vacuum vessel 1 after adjusting the vacuum degree to about 10 ⁻⁴ Torr via the pressure reducing control valve 18 and the flow meter 17. In this case, the vapor deposition film of the mixture of the metal compound and the metal can be formed by adjusting the amount of introduced gas. Further, by forming a metal vapor deposition film without introducing a gas and then introducing a gas to form a vapor deposition film of a metal compound, a two-layer composite vapor deposition film can be continuously formed.

The present invention is particularly applicable to the case where a long cathode, for example, a long round rod cathode having a length of about 500 to 1000 mm is used, or a small diameter cathode, for example, 10 to 20 mm in diameter.
When using the small diameter round bar cathode of, or the cathode sideways,
In the case of a deformed arrangement such as an oblique orientation or hanging, an effective strength improving effect is exhibited. In addition, especially regarding the base end of the cathode as shown in FIGS.
By using a refractory metal, the cathode can be firmly clamped and securely held by the cathode holding portion, and the holding stability of the cathode can be improved.

The vacuum vapor deposition method of the present invention as described above uses various low melting point metals or alloys for the purpose of improving various properties such as seizure resistance, lubricity and sealability on the inner surface of oil well pipe threaded joint pipes and the like. It is effective in various application fields such as when forming a functional coating film.

The present invention will be more specifically described below with reference to Examples and Comparative Examples.

Example 1 Vacuum evaporation was carried out by the apparatus shown in FIG. The specifications and working current of each member are as follows.

Object to be coated: inner diameter 90 mm, length 200 mm
SUS304 pipe Cathode: 30 mm diameter, 300 mm long round bar Core material: SS400 Tip length H = 50 mm Thickness of the portion covered with the coating material W ₂ = 15 mm Of the portion coated with the coating material Length (L in Fig. 2) = 230 m
m Length of base end portion (h in FIG. 3) = 20 mm Coating material: made of lead (purity 99.9% or more) Thickness W ₁ = 7.5 mm Shielding plate: opening diameter 40 mm, outer diameter 300 mm, thickness 5 mm
Alumina shielding plate (distance from the tip end of the core material to the base end side 41a is 5 mm) Current: 100 A As a result, the arc is maintained for 5 minutes to form a high-purity Pb vapor-deposited film having a vapor-deposited film thickness of 40 μm We were able to.

Comparative Example 1 Lead round bar without core (shape is the same as that of Example 1)
When a vapor-deposited film was formed in the same manner as in Example 1 except that No. 1 was used, it became impossible to maintain the arc due to deformation or melting of the cathode in about 1 minute.

As is clear from the above results, according to the present invention, in the vacuum vapor deposition method using the low melting point metal cathode, the arc running is continued for a time as long as 5 times longer than the conventional one, and the short time is sufficient. It is possible to form a vapor deposition film having various thicknesses.

[0040]

As described above in detail, according to the vacuum vapor deposition method of the present invention, in the vacuum vapor deposition method using the low melting point metal cathode, stable arc discharge is performed for a long time to achieve efficient vapor deposition. You can do it.

In particular, according to the method of the second aspect, it is possible to form a high-quality metal vapor deposition film having a high purity and containing no impurities.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a main part of a low temperature arc vapor deposition apparatus suitable for implementing the present invention.

FIG. 2 is an enlarged view of the cathode used in FIG.

FIG. 3 is a system diagram showing an outline of a low temperature arc vapor deposition apparatus used in the prior application.

[Explanation of symbols]

 1 Vacuum Container 2 Anode 3 Cathode 4 Object to be Painted 13 Power Supply Device 14 Control Panel 40 Cathode 41 Core Material 42 Covering Material 43 Shielding Plate

Claims (2)

[Claims] 1. A base material to be vapor-deposited is arranged in a vacuum container, and a metal body as an anode and a long metal rod as a cathode are arranged with their tips facing each other. In a vacuum deposition method for forming a metal deposition film of the low melting point metal on the surface of the deposition target substrate by evaporating the low melting point metal from the cathode by applying a DC voltage to and arc discharging As the cathode, a metal rod having a core material made of a metal having a melting point higher than that of the low melting point metal, and a coating material made of a low melting point metal for covering the side peripheral surface other than the tip end portion of the core material is used. A vacuum vapor deposition method characterized in that 2. The vacuum vapor deposition according to claim 1, wherein a shield plate is provided so as to separate the cathode surrounding region of the tip portion of the metal rod from the cathode surrounding region provided with the coating material. Law.