JPH0523579A - Surface processing and its device - Google Patents

Abstract

PURPOSE:To perform surface processing such as coating or etching on various materials efficiently in an atmosphere and further apply local processing by converting an atmospheric pressure glow plasma as a dot or a linear plasma by a simple technique. CONSTITUTION:A gas introduction orifice 2 to which a means for supplying gas is provided on the base end side of an insulator container 1 of glass with a tapered tip or a linear thin tip, and at the same time, a gas release orifice 3 is provided on the tip end side with an electrode 4 arranged inside. In addition, an alternating current voltage is applied from an AC power supply 7 connected to the electrode 4, and the surface of a material to be processed 6 is subjected to processes to make it hydrophilic and water-repellent as well as surface processes such as etching and coating using a clot or a linear plasma ejected from the gas release orifice 3 by a gas flow. In this case, the gas pressure becomes high near the tip opening as the tip of the insulator container 1 is tapered or linearly thin. Subsequently, it is possible to eject the dot or linear plasma efficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment method and apparatus for subjecting various materials to surface treatment such as coating and etching by plasma, and more particularly to a surface treatment method in which the object to be treated is placed in the atmosphere. The present invention relates to a surface treatment method and apparatus capable of performing local treatment.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Several methods are known as surface modification methods (surface treatment methods) for treating the surface of the base material to impart hydrophilicity, water repellency, etc. Among them, corona discharge treatment, low-pressure glow plasma surface treatment The electric discharge treatment method such as has attracted attention as a dry and clean treatment method.

Corona discharge treatment is performed at atmospheric pressure mainly in an atmosphere of air, nitrogen, etc., and is a cheap and simple treatment method among discharge treatments. However, in corona discharge, electrons are discharged in a beam shape, which causes uneven treatment on the surface of the object to be treated, and since the gas temperature is considerably higher than the gas temperature in low temperature plasma, surface treatment other than hydrophilization is performed. Is extremely difficult. Further, the degree of hydrophilization by corona discharge treatment is generally insufficient as compared with the case of plasma treatment.

On the other hand, in the low-pressure glow plasma treatment, a uniform surface treatment with less treatment unevenness can be performed, and various high-performance surfaces can be obtained by changing the atmospheric gas species, input power, frequency, pressure, etc. It is possible to obtain However, low pressure glow plasma treatment is usually 10 Tor
Since it is carried out at a low pressure of r or less, a large vacuum device is required when this is industrially carried out, and the equipment cost and the processing cost increase. Furthermore, when the object to be processed contains a large amount of water, gas plasticizer, etc., these are vaporized in a reduced pressure atmosphere and released from the surface of the object to be processed, so that the desired performance and function in plasma processing cannot be obtained. In some cases. Moreover, such a plasma treatment has a problem that heat is easily generated during the treatment, and thus it is difficult to apply it to an object to be treated which is made of a low melting point substance.

Further, as a surface treatment method which solves the problems of both treatment methods at the same time, a method of stably obtaining glow plasma at atmospheric pressure and treating the surface of a substrate using the glow plasma (atmospheric pressure glow plasma treatment) Method) has been proposed (JP-A-1-306569, JP-A-2-15171, etc.).

Since the surface treatment by the atmospheric pressure glow plasma method is carried out at a pressure near the atmospheric pressure, a large vacuum device is not required, and a substrate containing a large amount of water, a gas plasticizer, etc. can be satisfactorily used. It can be dealt with and almost no heat is generated during processing. Therefore, it has a feature that it can be applied to a base material having a low melting point, and the electrons discharged from the portion sandwiched by the two electrodes hardly spread, so that local treatment can be performed to some extent. It is also possible to treat only certain parts of the part.

However, in this atmospheric pressure glow plasma method, in order to stabilize the discharge, the processing chamber is provided with an inert gas such as helium, neon, argon, nitrogen, oxygen, etc.
It is necessary to create a gas atmosphere that facilitates glow discharge under atmospheric pressure including general-purpose gases such as hydrogen, and thus it has been impossible to treat the substrate placed in the atmosphere.
Moreover, although local treatment is possible to some extent as described above, local treatment in a narrower range such as a laser process is difficult.

As a method for solving such a problem,
Microbeam Plasma Method (Proceedings of the 38th Spring Meeting of the Japan Society of Applied Physics 1991, 28p-ZE-13, 1
4), and in this method, atmospheric pressure glow plasma discharge is used, and by using beam discharge with a diameter of 2 mm or less, pump-free and surface treatment such as coating and etching on various substrates at atmospheric pressure is possible. Can be applied locally.

However, in this method, an anode in the form of a metal frame or the like is required, and Teflon is used as an insulating material in order to suppress abnormal discharge and improve gas use efficiency. However, there was a limitation, and it was insufficient in terms of simplification of the device. Further, in this method, the discharge between the cathode and the anode cannot be efficiently used in the surface treatment, which is economically disadvantageous.

The present invention has been made in view of the above circumstances.
(EN) A surface treatment method and apparatus capable of efficiently performing surface treatment such as coating and etching of various materials even in the atmosphere using glow plasma and satisfactorily performing local surface treatment. The purpose is to

[0011]

Means for Solving the Problems and Actions The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, have an electrode inside the insulator container having a gas introduction port and a gas discharge port at the tip opening. And a flow of a predetermined gas is introduced into the insulator container from a gas inlet, and a voltage is applied to the electrode to generate plasma in the tip opening, and the plasma is supplied to the insulator container gas. We found that it is possible to efficiently perform surface treatment coating of various materials, etching, etc. by injecting from the discharge port to the outside,
The present invention has been completed.

Therefore, according to the present invention, the electrode is disposed inside the insulator container having the gas inlet and the tip opening being the gas outlet, and a predetermined gas is introduced into the insulator container from the gas inlet. While flowing, a voltage is applied to the electrode to generate plasma in the tip opening, the plasma is emitted to the outside from the gas discharge port of the insulator container, and the plasma is emitted at a position to be treated. A surface treatment method characterized by arranging an object to surface-treat an object to be treated, and an insulator container having a gas inlet and having a tip opening as a gas outlet, and inside the insulator container. Surface treatment of the object to be processed by the method described above, comprising an electrode to be arranged, a power supply for applying a voltage to the electrode, and a gas supply means for supplying a predetermined gas into the insulator container. I tried to do it To provide a surface treatment apparatus according to claim.

The present invention will be described in more detail below. The surface treatment method according to the present invention is as shown in FIGS.
An electrode 4 is arranged inside an insulator container 1 having a gas inlet 2 and having a tip opening as a gas outlet 3, and a flow of introducing a predetermined gas into the inside of the insulator container 1 from the gas inlet 2. At the same time, a voltage is applied to the electrode 4 to generate plasma at the gas discharge port 3 and the plasma is generated.
From the gas discharge port 3 to the outside, and by the spot-like or linear plasma 5, the surface of the object to be treated 6 arranged outside the gas discharge port 3 is made hydrophilic, water-repellent, and etched. The surface treatment such as coating is performed. In the method according to the present invention, since discharge is extremely stable, it is possible to generate discharge in the atmosphere.
In this case, it is preferable that the tip of the electrode is disposed inside or outside the tip opening of the container 1.

Here, the material of the insulator container is not particularly limited as long as it is made of glass, ceramic, plastic, rubber or the like and has a predetermined shape. The insulator container is not limited as long as it can generate plasma, and any size, shape, or the like can be used. It is preferable that the nozzle has a nozzle shape, and it is particularly preferable that the diameter of the nozzle tip portion is several mm or less.

The electrode, which is arranged inside the insulator container and to which a voltage is applied, can generate plasma, and
If it can be placed inside the insulator container,
Any size, shape, etc. can be used, but the point where plasma is generated is easier to discharge when it is sharp, and since stable discharge can be obtained, it is effective to make it wire-shaped. is there. The material of the electrode may be a metal such as tungsten or stainless steel, or a conductive substance such as a wire, but is not limited thereto as long as it is a conductive substance.

The gas that can be used in the surface treatment method according to the present invention is a gas that is easily subjected to atmospheric pressure glow discharge for stably obtaining atmospheric pressure glow plasma, and this gas flows in the insulator container. By doing so, plasma can be emitted from the gas discharge port of the insulator container. At the same time, a gas that is appropriately selected depending on the type of treatment can be used, and specifically, all gases conventionally used in atmospheric pressure glow plasma treatment, low pressure glow plasma treatment, etc. are used. Can be used accordingly.

In order to stably obtain the atmospheric pressure glow plasma, it is preferable to dilute the gas selected according to the type of treatment with a gas such as the former inert gas which easily causes the atmospheric pressure glow discharge. Specifically, one or a mixture of two or more kinds of substances, such as an inert gas such as helium, neon, argon, or nitrogen, a general-purpose gas such as oxygen or hydrogen, which easily causes an atmospheric pressure glow discharge, is used. However, helium, neon and the like are particularly preferable.

These gases do not necessarily have to be gaseous at room temperature, and the supply method is selected depending on the temperature of the discharge region, the state at room temperature (solid, liquid, gas). That is, when it is gaseous at the temperature of the discharge region or at room temperature, it can be flowed into the processing container as it is, and when it is liquid, if the vapor pressure is relatively high, the vapor can flow in as it is. Alternatively, the liquid may be bubbled with an inert gas or the like to flow in. On the other hand, when it is not in a gaseous state and has a relatively low vapor pressure, it can be used in a state of being in a gaseous state or a high vapor pressure by heating.

In order to supply gas more efficiently, it is also possible to separately supply a gas that is susceptible to atmospheric pressure glow discharge and a gas selected according to the type of treatment. That is, a gas that is easily subjected to atmospheric pressure glow discharge is caused to flow in the insulator container, while a gas appropriately selected according to the type of treatment is sprayed from the tip opening (gas discharge port) of the insulator container or plasma. A method of spraying from another gas supply port during discharge can also be adopted. By this method, a stable plasma can be efficiently and easily generated with a gas that is easily subjected to atmospheric pressure glow discharge, and a gas corresponding to the type of surface treatment can be excited by the plasma.

As the plasma generating method according to the present invention, any method can be adopted as long as it is a method capable of generating plasma in the vicinity of the tip end portion in the insulator container.
There are roughly two types of voltage application methods, direct current and alternating current. In both direct current and alternating current, voltage is applied to the electrodes in the insulator container, but alternating current discharge is industrially easier.

In the case of direct current, an electrode on the ground side is required,
In this case, since a DC current flows into the ground electrode, it is not preferable to cover the ground electrode with an insulator. By arranging the ground electrode near the opening of the tip of the insulator container, plasma is generated between the electrode arranged inside the insulator container and the ground electrode. Here, when the surface treatment is performed on the object to be processed made of a conductive material, the object to be processed may be placed on the ground electrode as it is (see FIG. 5). Further, when the object to be processed is made of a non-conductive material, it is necessary not to completely cover the ground electrode with the object to be processed but to leave an escape path for the electric current (see FIG. 6).

On the other hand, in the case of alternating current, plasma can be generated without the ground electrode. That is, it can be discharged by the floating capacitance. In this case, the frequency can be any frequency of several Hz or higher used for normal AC discharge, but a frequency of several hundreds to tens of thousands Hz is preferable from the viewpoint of easy matching and beam spreading. Particularly preferably used.

The plasma thus generated controls the plasma discharge by forming a magnetic field in the vicinity of the opening of the insulator container by using a magnet (see FIG. 2).
By using a magnet for the plasma emitted from the tip opening of the insulator container, the amount of plasma drawn can be improved (see FIG. 3) and the direction of the plasma can be controlled (see FIG. 4).

In the surface treatment method of the present invention, when an apparatus in which one electrode is arranged in an insulator container is used, local treatment can be performed, but a plurality of electrodes are formed into a desired shape. By arranging them, processing in a desired range can be performed (see FIGS. 10 and 12). Further, by connecting a plurality of insulator containers in each of which one electrode is arranged, treatment in a desired range can be performed (see FIG. 14). Further, by making the shape of the electrode a knife edge type, it is possible to perform linear treatment (see FIG. 15).

In the surface treatment method of the present invention, not only surface treatment such as water repellent treatment and hydrophilic treatment but also etching, coating and the like can be performed.

The treatment according to the present invention can be carried out in the atmosphere without using a treatment chamber, and in this case, the shape of the object to be treated may be any shape such as spherical, block-shaped, plate-shaped or rod-shaped. Also, there is no size limit.

Next, an example of a suitable apparatus used for carrying out the above-mentioned surface treatment of the present invention will be described with reference to FIGS.
FIG. 1 shows that a gas inlet 2 to which a gas supply means (not shown) is connected is provided at the base end side of a glass-made tapered insulator container 1, and a gas discharge port 3 is provided at the tip end side. This is an example in which the electrode 4 is arranged, and an AC power source 7 connected to the electrode 4
AC voltage is applied to the surface of the object 6 to be processed by the point-shaped (beam-shaped) plasma 5 emitted from the gas discharge port 3 by the gas flow. In this device, since the shape of the insulator container 1 is tapered, the gas pressure in the vicinity of the opening at the tip end is increased, and therefore point plasma can be efficiently emitted.

FIG. 2 shows an example in which the discharge of the plasma generating portion A is controlled and activated by arranging a magnet 8 at the gas discharge port 3 of the insulator container 1 to form a magnetic field in the same apparatus as in FIG. (Where plasma is generated by magnetic field formation A
Intensity increases.)

FIG. 3 shows a device similar to that of FIG.
This is an example in which the amount of the point-like plasma 5 drawn out is improved by placing the object 6 to be processed on top.

FIG. 4 shows a device similar to that of FIG.
Is an example in which the direction control of the microbeam plasma is performed by arranging the obliquely below the insulator container 1.

FIG. 5 shows an example in which a DC power source 10 is used instead of the AC power source 7 in FIG. 1 for discharging. In this case,
The ground electrode 11 is required. When the object to be processed made of the conductive material or the object to be processed 12 containing the conductive material is subjected to the surface treatment, it is only necessary to place the object to be processed 12 on the ground electrode 11.

On the other hand, the object to be processed 13 made of a non-conductive material
In the case of processing, the ground electrode 11 as a whole must not be completely covered with the object to be processed 12 as shown in FIG. 6, and a current escape path B for the current to escape to the ground electrode 11 must be created. Even in the case of direct current discharge, beam control with a magnet as shown in FIGS. 2 to 4 is possible.

In FIG. 7, only a gas that is apt to undergo atmospheric pressure glow discharge is caused to flow from the gas inlet 2 to generate plasma 5, and a gas corresponding to the type of surface treatment is supplied from the side of the plasma 5 through the gas supply pipe 14. Here is an example.

FIG. 8 shows an example in which a material 15 such as a metal is placed in the vicinity of the gas discharge port 3 of the insulator container 1 and is etched and deposited on the object 6 to be processed. A thin film of material 15 is formed on top.

FIG. 9 shows an object to be processed 13 made of a non-conductive material.
Is an example in which is placed on a conductive holder 16 and surface-treated. In this method, plasma is more activated and efficient processing is possible.

In FIGS. 1 to 9, the electrode 4 inside the insulator container 1 may protrude to the vicinity of the gas discharge port 3 or to the outside thereof.

FIG. 10 shows a gas inlet 17 and a gas outlet 18.
This is an example in which the comb-shaped electrode 20 is arranged inside the insulator container 19 in which is provided, and the treatment is performed at a plurality of points arranged in a straight line. FIG. 11 is a view of the apparatus of FIG. 10 as seen from below.

FIG. 12 shows a gas inlet 21 and a gas outlet 22.
The brush-shaped electrode 24 is arranged inside the cylindrical insulator container 23 provided with the structure shown in FIG. 13 (a view of FIG. 12 seen from below).
This is an example of processing the parts arranged in line.

It should be noted that, in FIGS. 10 to 13, the gas discharge ports 18 and 22 do not correspond to the electrodes one by one as shown in the drawing, but may be one large discharge port.

FIG. 14 shows an example in which a plurality of the devices shown in FIG. 1 are connected in a line, and the same processing as that of the device shown in FIG. 10 can be performed by such connection.

FIG. 15 shows an example in which a knife-edge type electrode 26 is arranged inside an insulator container 25 whose tip is linearly opened. Using this device, a linear plasma 27 can be obtained, and therefore the target plasma can be obtained. The surface of the processed product can be processed into a linear shape.

[0042]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to the following examples. In the following examples, all the objects to be treated were placed in the atmosphere.

Example 1 In the apparatus shown in FIG. 1, the gas flowing from the gas inlet 2 is helium (2 liters / minute).
And A tungsten wire having a diameter of 0.5 mm was used as the electrode 4. The insulator container 1 used had an inner diameter of 5 mm and the gas discharge port 3 had an inner diameter of 2 mm. When an AC voltage with a frequency of 5 kHz is applied from the AC power supply 7, the length is 2c
It was possible to obtain the micro-beam plasma 5 having a beam diameter of about 1 mm at about m.

An ETFE (ethylene tetrafluoroethylene copolymer) resin sheet is used as the object 6 to be treated, which is subjected to a hydrophilic treatment with the above beam for 1 minute, and the degree of surface treatment in the circumferential direction of the object is treated with water droplets on the surface. It was examined by measuring the contact angle. The smaller the contact angle of water droplets, the higher the degree of hydrophilic treatment of the surface of the object to be treated. The water droplet contact angles on the surface of the ETFE resin sheet are 98 degrees and 60 degrees before and after the treatment,
From these results, it can be seen that when the surface treatment method according to the present invention is used, good hydrophilic treatment is performed.

Next, under the same conditions as in FIG. 1, magnets were further arranged as shown in FIGS. 2 and 3 to make ETFE hydrophilic. In the case of FIGS. 2 and 3, the contact angle of water droplets after treatment is 55 degrees,
It is 40 degrees, and it can be seen that a more excellent hydrophilic treatment can be performed by controlling and activating plasma with a magnet as shown in FIGS.

Example 2 A DC voltage was applied using the apparatus shown in FIG. Point-like microbeam plasma was generated at an applied voltage of 1.5 kV or higher. Next, the ground electrode 11
When the ETFE resin 13 was placed on the surface of the ETFE resin 13 and the surface of the ETFE resin 13 that had been exposed to the beam-shaped plasma for 1 minute was measured for a water droplet contact angle, it was 42 degrees. As described above, it can be seen that good processing can be performed by direct current discharge as in the case of alternating current.

[Embodiment 3] Using the apparatus shown in FIG. 7, helium gas was supplied from the gas inlet 2 under the same conditions as in Embodiment 1, an AC voltage was applied to the electrode 4, and a beam-shaped microbeam plasma was obtained. Got 5. When a polymerizable gas (butadiene) was supplied from the gas supply port 13 at a supply rate of 50 ml / min, a polymerized film of butadiene was found on the object to be treated 6.

[Embodiment 4] In the apparatus shown in FIG.
An aluminum foil is attached as a material 15 near the gas outlet 3, and helium gas (2 liters / minute) is supplied from the gas inlet 2.
And a mixed gas of CF ₄ (50 ml / min) was supplied. An AC voltage having a frequency of 5 Hz was applied to the electrode 4 to form a dot-shaped microbeam plasma 5.
Was etched, and an aluminum thin film was seen on the object 6 to be processed.

From Examples 3 and 4, it was confirmed that coating and etching were possible by the surface treatment method according to the present invention.

[Embodiment 5] The object to be treated 6 is processed by the apparatus shown in FIG.
When a conductive material (aluminum plate) was placed as, the microbeam plasma 5 was remarkably activated. Further, when a material containing a conductive material (vulcanized rubber containing carbon black) was placed as the object 6 to be treated, the microbeam plasma was remarkably activated.

Example 6 In the apparatus shown in FIG. 9, the conductive material 16 was used as a holder for the non-conductive film 13 (ETFE), and the non-conductive film 13 was treated with beam-shaped plasma. The microbeam plasma 5 was remarkably activated as compared with the case where the holder 16 was not used.

[0052]

As described above, according to the present invention, the atmospheric pressure glow plasma is formed into a spot-like or linear plasma by an extremely simple method, so that surface treatment such as coating and etching of various materials can be performed in the atmosphere. It can be carried out efficiently inside, and local processing can also be carried out.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a first embodiment of a surface treatment apparatus of the present invention.

FIG. 2 is a schematic cross-sectional view showing a second embodiment of the surface treatment apparatus of the present invention.

FIG. 3 is a schematic cross-sectional view showing a third embodiment of the surface treatment apparatus of the present invention.

FIG. 4 is a schematic sectional view showing a fourth embodiment of the surface treatment apparatus of the present invention.

FIG. 5 is a schematic sectional view showing a fifth embodiment of the surface treatment apparatus of the present invention.

FIG. 6 is a schematic sectional view showing a sixth embodiment of the surface treatment apparatus of the present invention.

FIG. 7 is a schematic sectional view showing a seventh embodiment of the surface treatment apparatus of the present invention.

FIG. 8 is a schematic sectional view showing an eighth embodiment of the surface treatment apparatus of the present invention.

FIG. 9 is a schematic sectional view showing a ninth embodiment of the surface treatment apparatus of the present invention.

FIG. 10 is a schematic sectional view showing a tenth embodiment of the surface treatment apparatus of the present invention.

11 is a bottom view of the device shown in FIG.

FIG. 12 is a schematic sectional view showing an eleventh embodiment of the surface treatment apparatus of the present invention.

13 is a bottom view of the device shown in FIG.

FIG. 14 is a schematic sectional view showing a twelfth embodiment of the surface treatment apparatus of the present invention.

FIG. 15 is a schematic perspective view showing a thirteenth embodiment of the surface treatment apparatus of the present invention.

[Explanation of symbols]

1,25 Insulator container 2,17 gas inlet 3,22 Gas outlet 4,26 electrodes 5 Microbeam plasma 6,13 Objects to be processed 7 AC power supply 10 DC power supply 11 Ground electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number in the agency FI Technical indication C23C 14/12 8414-4K 16/12 7325-4K (72) Inventor Masato Yoshikawa Ogawa, Kodaira-shi, Tokyo 3-5-9-202 Higashimachi (72) Inventor Toshio Naito 969-1 Makinagi, Miyamae-ku, Kawasaki City, Kanagawa Prefecture (72) Inventor Sachiko Okazaki 2-20-11, Takaido East, Suginami-ku, Tokyo (72) Inventor Masuhiro Ogoma 843-15 Shimoshinkura, Wako City, Saitama Prefecture

Claims (4)

[Claims] 1. An electrode is arranged inside an insulator container having a gas inlet and a tip opening being a gas outlet, and a predetermined gas is introduced into the insulator container through a gas inlet flow. A voltage is applied to the electrode to generate plasma in the tip opening, the plasma is emitted to the outside from the gas discharge port of the insulator container, and the object to be processed is placed at the position where the plasma is emitted. A surface treatment method comprising the step of surface-treating an object to be treated. 2. The method according to claim 1, wherein the tip of the electrode is disposed inside or outside the tip opening of the insulator container. 3. An insulator container having a gas inlet and having a tip opening as a gas outlet, an electrode arranged inside the insulator container, and a power supply for applying a voltage to the electrode. A surface treatment apparatus comprising: a gas supply unit that supplies a predetermined gas into the inside of the insulator container, and the object to be processed is surface-treated by the method according to claim 1. 4. The device according to claim 3, wherein the tip of the electrode is arranged inside or outside the tip opening of the insulator container.