JP2008174790A - Surface treatment method for metal fiber textile, and article obtained thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high quality metal fiber textile obtained by smoothing the surface of each stainless mesh composed of a fine textile such as a screen printing board for a printed wiring and a large area filter used for electronic device parts, and in which the rigidity and tensile strength of the textile are improved, and to provide an article coated with a high quality DLC (Diamond Like Carbon) film with a gradient structure by carbon ion implantation which is obtained by introducing a hydrocarbon based gas comprising carbon of at least one or more atoms in a reduced pressure, so as to generate plasma, and by applying a negative high frequency pulse voltage thereto. <P>SOLUTION: Disclosed is a metal fiber textile member obtained by introducing a hydrocarbon based gas comprising carbon of at least one or more atoms in a state where many screen meshes are set, and feeding high frequency electric power, so as to generate plasma, applying high frequency voltage to the object to be treated therein, implanting carbon ions into a base material, and thereafter forming a DLC film. Also disclosed is a surface treatment method therefor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention smoothes the surface of a stainless mesh made of a fine fabric such as a screen printing plate for printed wiring and a large area filter used for electronic device parts, and improves the stiffness (elastic modulus) and tensile strength of the fabric, The present invention relates to a surface treatment method in which physical properties of a metal fiber fabric are improved in order to keep a mesh gap constant against printing stress, and an article thereof.

  Many fine printed wiring boards are used in various electronic devices typified by personal computers, mobile phones, liquid crystal digital televisions, digital cameras, car navigation devices, and broadband information terminals. The printed wiring board is increasingly miniaturized, and the screen printing plate for printing the wiring pattern is required to have an ultra fine fiber fabric. Since the wiring width depends on the screen mesh width, the screen mesh is narrowed to an interval of 10 to 20 μm. For this reason, the strength and rigidity of the fiber fabric are reduced, and the mesh is deformed at the time of pattern printing, so that accurate printing cannot be performed. For this reason, there has been a demand for a metal fiber mesh having a higher strength and rigidity than a conventional high-precision ultra-flat surface.

Screen printing plates for forming fine printed wiring boards include screen printing plates made of polyester fibers, which are organic fibers, and stainless mesh printing plates made of metal fibers. However, a screen printing plate made of polyester fiber has a large expansion and contraction and is not suitable for a screen for forming fine wiring. For this reason, stainless steel mesh printed wiring plates are often used for wiring screens having a wiring pattern width of 100 μm or less, and have high rigidity and little deformation with respect to tension during ink printing with a polyurethane squeegee.

In these stainless steel meshes for fine wiring, the diameter of the stainless steel fiber has been further reduced from the conventional 30 μm to the vicinity of 10 μm, and the tensile strength, elongation rate, and elastic modulus of the stainless steel fiber have become major issues. If the deformation when printing several hundreds or thousands of times from the initial is not constant with respect to the pressing tension by the polyurethane squeegee at the time of wiring printing, a predetermined printed wiring width cannot be obtained. For this reason, the screen printing plate is required to maintain a certain amount of deformation with respect to a certain stress during printing and to reduce repeated fatigue.

Currently, stainless steel, chrome-plated steel, nickel alloy fibers, and the like are considered as metal fiber fabric members, but stainless steel mesh is often used from the viewpoint of performance and price. Further, 304, 316, 440, etc. are used as stainless steel, but advanced fiber technology is required to process into a fiber having a diameter of several tens of μm. In particular, weaving machine performance and fiber tension need to be optimized in order to supply a large-area woven fabric while maintaining the highest tensile strength, elongation and elasticity of stainless steel fibers.

A fine stainless steel screen woven under optimum conditions makes it difficult to finish a uniform printing plate due to slight deformation and local stress. For this reason, careful attention is required to form a wiring pattern by coating a resist on a screen printing plate. However, even if a good wiring pattern is formed, it is difficult to maintain a constant printing plate for hundreds to tens of thousands of screen printings. For this reason, attempts have been made to improve the strength and rigidity of stainless steel mesh by surface modification.

JP, 2000-96233, A There has been an attempt to improve the surface treatment method to those which are weak against heat and stress by a method using plasma. As described in JP-A-2000-96233, in the plasma CVD method, the plasma generation method, applied voltage, gas composition, etc. have been devised to develop a plasma CVD apparatus capable of low-temperature processing as much as possible. A method of forming a DLC film on the surface of a molded product has been proposed, and further, it has been proposed to use it for camera O-rings, automobile wiper rubbers, and the like. However, these plasma CVD methods are methods in which the introduced gas is turned into plasma at a high frequency, and the activated carbon element is chemically reacted and deposited on the surface of the component. Therefore, the chemical reaction between the member surface and the DLC film layer is performed. Bonding strength is weak and adhesion may be poor.

In particular, the stainless steel mesh used in the present invention must be subjected to a surface treatment that is very weak against mechanical stress and thermal strain and is mild. For this purpose, in order to lower (weaken) the plasma density, it is necessary to modulate the high frequency to generate a soft plasma to form a film. In order to attract carbon ions in the plasma, it is common to apply a bias voltage of several tens of volts to several hundreds of volts. However, with such a voltage, the carbon element is attached to the surface layer portion of the substrate. Therefore, it is not possible to implant ions into the base material (several tens of nm or more). Therefore, in the plasma CVD method, in order to improve the adhesion to the base material, silicon as a base treatment layer, silicon oxide, silicon nitride, silicon carbide, titanium tetrachloride, pentaethoxytitanium, tetraisoproxytitanium, etc. are used. It is necessary to improve the adhesion to the substrate by introducing an intermediate layer of a compound of silicon or titanium and carbon.

Also in the PVD method (physical vapor deposition method) that forms a film by sputtering a carbon solid target, a DLC film is formed by heating the substrate temperature of metal or ceramic at 300 to 500 ° C. in order to improve adhesion. In addition, it was necessary to form a film by depositing silicon or chromium material, which is compatible with carbon, as a base treatment. Further, in order to attract carbon ions in plasma, it is common to apply a DC or AC bias voltage of several tens of volts to several hundreds of volts. This voltage is used as film forming energy, It is not possible to greatly improve the adhesion.

Furthermore, it is necessary to provide a device with a special reaction mechanism in order to uniformly apply the base, and a rotation mechanism is indispensable in order to ensure the uniformity of the film thickness. It could only deal with products with a certain shape. In particular, the metal fiber fabric member processed in this proposal consists of a high-precision mesh with a large area ranging from 500 to 800 mm on a side and a thickness of 0.03 to 0.06 mm, and a DLC film is uniformly and well formed on this surface in a 0.1 μm system. There is a need.

  In the above plasma CVD method, if the area is large, the mesh material is distorted and processing accuracy cannot be obtained. In the PVD method, even if DLC film formation is performed with a rotation mechanism, the film thickness cannot be made uniform. A thickness variation of 1 μm or more occurred. Furthermore, the film forming process has become complicated in both cases, and the processing cost has increased.

With the above-described technology, it is difficult to uniformly form a DLC film on a metal fiber fabric member, and a process capable of forming a uniform DLC with high accuracy, low cost and without a complicated rotating mechanism has been desired.

In the present invention, a surface layer of a metal fiber fabric member composed of a high-precision mesh having a large area ranging from 500 to 800 mm on a side and a thickness of 0.03 to 0.06 mm is modified by using a plasma-based ion implantation technique. A functional DLC film is formed on the surface layer, and a new DLC film formation process and a high-quality DLC-coated metal fiber fabric member that cannot be performed by physical film formation process (PVD) or chemical film formation process (CVD) It is to provide.

  A conventional diamond-like carbon film, or DLC film, has high hardness, excellent wear resistance, electrical insulation, hydrophilicity, etc., and the carbon content varies depending on the film formation method and raw materials used, and has various hardness. A membrane was obtained. In particular, the plasma CVD method, the sputtering method, the ion plating method, etc. have high hardness and excellent wear resistance, but they are not suitable because they have poor adhesion to the base material. The method is applied to the surface of a metal fiber fabric member made of various metal materials, and is provided as a surface modification technique that improves tensile strength, rigidity (elastic modulus), deformation resistance, wear resistance, and slip resistance.

  The present invention performs plasma generation by RF plasma by an external antenna or self-bias voltage around a metal fiber woven member (base material) by using plasma-based ion implantation / film formation method. By applying a negative pulse voltage of several tens of kV and implanting ions containing carbon into the surface of the molded product, a carbon gradient layer is formed, and further, a DLC film containing carbon and hydrogen is formed while controlling the voltage. In this way, the above-mentioned problems can be solved and the object can be achieved.

Most metal fiber fabric members are metal meshes such as stainless steel, chrome-plated steel, nickel alloy, etc., but since the fiber diameter is very fine, 30μm to 10μm and the fabric is easily deformed, arc discharge at low temperature It is necessary to form the DLC film under the condition that there is no such as. When slight discharge occurs, a hole is generated in the mesh at that portion, resulting in a defective product.

Specifically, surface modification of metal fiber fabric members using equipment configured in a vacuum chamber, vacuum exhaust system, gas supply / treatment system, high-frequency plasma source, negative high-voltage pulse power supply / high-pressure introduction system and cooling system do. Power can be supplied by simply connecting an electrode lead wire to a metal, but an insulator for ceramics, rubber, plastic, etc. is provided with an electrode for applying a voltage on the back or in the center to supply power to a high-frequency plasma source. When a negative high voltage pulse voltage is applied around the injection target (metal, plastics) by supplying a gas plasma, electrons in the plasma are expelled, and ions are scattered around the outline of the injection target. A sheath is formed. The ion sheath is covered along the contour of the implant, and then a negative voltage is applied to the ion sheath, so that only ions are attracted and accelerated from all directions to the implant and aim at the implant. Elements are ion-implanted.

  In the present invention, carbon ions can be implanted into fine objects such as a metal mesh. Conventionally, since positive ions are implanted by applying a DC bias voltage, there is a case where an insulator such as a fastener is charged and breaks down due to a charge-up charge. In the method of applying a high-frequency, high-voltage negative pulse voltage according to the present invention, since the pulse is a pulse, the plasma approaches the base material when there is no pulse voltage, the charge charged on the base material is released into the plasma, and the charge-up is eliminated. The Further, by optimizing the pulse frequency and application time for each shape, it is possible to prevent dielectric breakdown and to prevent film non-uniformity and film formation rate decrease due to charge-up.

Parameters affecting the characteristics of plasma-based ion implantation and deposition include the frequency of the high-frequency plasma source, plasma amplification voltage, repetition frequency, number of pulses, etc., and parameters on the high-voltage induced pulse power supply side include applied voltage and current current. The number of repetitive pulses, the pulse width, the delay time, etc., and the gas flow rate, gas pressure, etc. of the plasma generation raw material have an effect. By controlling these, an ion sheath is formed along the contour of the injection target, and only ions are injected into various metals, ceramics, and plastic moldings that are the injection target. The present invention provides a method of coating a metal fiber fabric member surface with a DLC film having improved deformability, wear resistance and slip resistance, and a coated article thereof.

  The hydrocarbon-based gas of the present invention uses a gas mainly composed of at least one selected from hydrocarbon compounds composed of methane, acetylene, benzene, toluene, cyclohexanone, chlorobenzene, etc., and is introduced into the vacuum chamber. Then, it is preferable to generate a carbon atom or a molecular ion by applying a high frequency voltage to turn the gas into a plasma, and accelerating the ion to perform ion implantation.

  As a method for selecting a hydrocarbon-based gas, the plasma state varies depending on the ratio of carbon atoms and hydrogen atoms, and it is preferable to determine the gas species and the mixing ratio thereof depending on what percentage of hydrogen atoms are contained in the DLC film. . In methane, acetylene, benzene, and toluene gases, it is known that the degree of carbon ion implantation and the state of film formation of the DLC film vary greatly depending on whether aliphatic or aromatic, and carbon difluoride as required. , Carbon tetrafluoride, carbon hexafluoride, sulfur hexafluoride, tetradecafluorocarbon, etc. to add DLC film with functions such as lubricity and water repellency. It is desirable to select.

  As the high frequency power for generating gas plasma, it is desirable that the frequency is 0.2 MHz to 2.45 GHz, the output is 10 W to 20 kW, and the pulse width is 1.0 μsec or more. The reason is that if the frequency is lower than 0.2 MHz, plasma decomposition of the gas is not sufficient and the deposition rate does not increase, and if it is higher than 2.45 GHz, the stability of plasma generation and the cost of the apparatus increase. is there. This is because if the high-frequency output is 10 W or less, the plasma density is low and film formation cannot be performed even if ion implantation is possible, and if it is 20 kW or more, the power supply capacity is large and the apparatus cost is increased. Further, when the pulse width is 1.0 μsec or less, the substantial ion implantation time is shortened, and in the case of an insulator, it is easy to charge up.

Furthermore, not only the above plasma generation but also a high frequency pulse application power source is very important. In the conventional mass separation type ion implantation, it is possible to inject only carbon ions after being excited by an electric field using a commercially available gas such as methane or acetylene. However, in the plasma method, a negative high voltage is applied to various substrates in a pulsed manner, and molecular ions bonded to carbon are also simultaneously implanted as impurities. The inventors of the present application have found that the following high-frequency pulse application conditions are suitable as a result of various investigations of favorable plasma conditions that can sufficiently inject carbon ions even in the presence of these extra ions.

As the high-frequency pulse applied voltage, it is necessary to optimize the frequency, pulse width, and applied voltage. The reason is that if the frequency is 100 Hz or less, the number of ion implantations within a certain period of time decreases, and the ion implantation efficiency decreases. On the other hand, if the frequency is 5000 Hz or higher, it is necessary to improve the performance of the high-frequency pulse power supply, resulting in an increase in device cost. The pulse width is greatly related to the sheath width at the time of ion implantation. If the width is narrow, the sheath is formed along a complicated shape and is uniformly implanted, but if the width is wide, the sheath cannot be formed in the narrow gap. The injection volume is reduced. From this, if the pulse width is 1.0 μsec or less, the ion implantation time of one pulse is short, so that the ion implantation efficiency is lowered and an expensive high-frequency power source is required to form a nano-second order pulse width. Equipment cost increases. On the other hand, if the pulse width is wide and 1000 μsec or more, the plasma density supplied to the periphery of the molded product will be reduced, and not only the ion implantation efficiency will be reduced, but also high performance of the pulse power supply will be required, leading to an increase in equipment cost. Become.

A particularly preferable negative pulse voltage is preferably -1.0 to 30 kV from the viewpoint of adhesion of the substrate, tensile strength, rigidity, deformation resistance, wear resistance, and slip resistance. When it is −1.0 kV or less, the ion implantation depth into the substrate is shallow, the inclined structure between the substrate and the carbon film cannot be obtained, and it does not contribute to the improvement of the adhesion, and the high voltage is −30 kV or more. Inclined structure between the base material and DLC film has progressed, but the high-frequency pulse power supply has increased in size, resulting in a significant increase in equipment costs. The generation of strain becomes remarkable, and 30 kV or more is not preferable.

  The time for ion implantation onto the surfaces of various substrates is not limited, but is preferably 30 to 120 minutes. More preferably, it is a short-time treatment from the viewpoint of productivity, but in the plastic fastener part of the metal fiber woven member, the surface layer becomes brittle due to the injection of the carbon element, and the adhesion may be lowered. It is necessary to select conditions.

  In conventional ion implantation by mass separation, the injection current is less than mA, and in the case of high energy, it is on the order of several A. Therefore, it takes several hours to implant 1E17ions / cm2. On the other hand, in plasma-based ion implantation, a current flows into the molded product from the periphery at a time, so that a current of several A to several tens of A flows, thereby enabling a carbon ion implantation process in a short time. In addition, since the ion implantation is performed not by direct current but by pulse, damage to the insulator due to charge-up is very small.

In the carbon ion implantation method of the present invention, ions are implanted with an energy sufficient to sufficiently penetrate the surface oxide layer, so that it is possible to easily form a carbon gradient structure. It is possible to form a DLC film while increasing the surface hardness by implanting carbon ions at a high energy for non-ferrous metals that are difficult to perform, and also by changing the DLC film formation energy and suppressing the elastic modulus of the DLC film. It is possible. As a result, the residual stress in the DLC film is low and adhesion is easily obtained. For this reason, it is possible to easily obtain a DLC film in the range of 2.0 to 10 μm in a metal fiber woven member that requires tensile strength, rigidity, deformation resistance, and wear resistance.

In a sputtering film forming method in which a conventional graphite target is used as a raw material, carbon particles called droplets exist in the DLC film, and a large number of minute pinholes are generated, resulting in a significant loss of corrosion resistance. In the carbon ion implantation + DLC film forming method of the present invention, an arbitrary amount of carbon can be implanted to easily form a carbon gradient structure, and the upper carbon layer is ionized by plasma decomposition of hydrocarbons. Since it is an amorphous carbon deposit obtained by recombining only the carbon that has been formed, a very dense DLC film without droplets or pinholes can be formed.

In this process, since it is possible to form the film while suppressing the elastic modulus of the DLC film by changing the energy at the time of forming the DLC film, the residual stress in the carbon film is low and the adhesion can be easily obtained. For this reason, it is possible to easily obtain a carbon film of 2.0 to 10 μm, and the residual strain has an effect on a metal fiber woven member made of a high-precision mesh with a large area ranging from 500 to 800 mm on a side and a thickness of 0.03 to 0.06 mm. Therefore, the DLC film can be uniformly formed with an accuracy of 0.5 μm or less, and it was found that this process is optimal.

The DLC film-forming metal fiber fabric member of the present invention is characterized in that carbon is ion-implanted by 10 nm or more from the surface of the non-processed material, and a hard DLC layer is formed at least 1.0 to 10 μm on the surface layer portion. . In the conventional plasma CVD method, PVD method, etc., in order to attract carbon ions in the plasma, it is common to apply a DC voltage or an AC bias voltage of several tens to several hundreds V. Carbon atoms were not ion-implanted by more than 10 nm from the surface of the object, and it did not contribute to improving the adhesion to the substrate.

As a result of evaluating various changes in high-frequency pulse voltage, pulse width, frequency, loading time, processing temperature, etc., the fact that deeper carbon atoms are implanted from the surface of the workpiece contributes to improved adhesion. I found it. As a result of the experiments so far, it is preferable that at least 10 nm or more of ions are implanted, and if it is shallower than this, it has been found that the contribution ratio to the adhesiveness decreases. The reason for this is thought to be that the residual stress of the carbon film to be formed cannot be relaxed in the tens of atomic layers from the surface layer, and a hundred atomic layers are necessary.

When carbon atoms are implanted deeper than the surface layer and a hard DLC film layer formed on the surface is formed at least 1 to 10 μm, the DLC film having rigidity, wear resistance, and corrosion resistance has a greater effect. Demonstrate. Conventional plasma CVD methods, PVD methods, etc. have generally formed a 0.1-2.0 μm carbon film due to residual stress generated at the substrate interface. As a result, the residual stress generated at the substrate interface was reduced, and the formation of a DLC film of 3.0 μm or more was facilitated. According to experiments, it was found that, for example, a DLC film having a thickness of 20 to 50 μm can be formed on a flexible aluminum substrate, and can be applied as a sliding member having a high function and a long life.

Furthermore, what is important in the metal fiber woven member is that impurities do not elute for application to a semiconductor screen. In metal fiber woven members using conventional chrome-plated steel, trace impurities such as iron and chromium are eluted, which may adversely affect the wafer.
The metal fiber woven member formed with the DLC film of the present invention is found to be useful for reducing the metal elution by the carbon ion implantation effect, and further, the metal fiber woven material in which the elution of impurities is not detected at all by the uniform DLC film formation. It became possible to obtain a member. A carbon ion implantation layer having a thickness of 10 nm or more was formed from the surface layer of the object to be treated of the present invention, and the carbon film was formed on the surface layer higher than the original carbon element concentration by several tens at% or more, thereby performing ion implantation It is inferred that the base material reduces the interatomic distance and suppresses metal elution.

  In the metal fiber fabric member of the present invention, the metal and the fixed frame are attached to the negative voltage application sample stage and integrated with the high voltage feedthrough. Radio frequency (RF) power is applied between the feedthrough and the chamber, electrons are reciprocated by the electric field change between them, and gas molecules are ionized by repeating collisions with gas molecules to form a high-density plasma. . Since ions, radicals, and electrons coexist in the plasma, if a high voltage pulse voltage is applied, the ions in the plasma can be injected into a composite substrate such as a metal. Ions of several tens of volts) are deposited on the surface, and at this time, carbon elements are bonded by radical polymerization to form a film. Using this superposed plasma ion implantation / deposition apparatus, ion implantation / deposition or a combination of ion implantation and deposition can be performed by controlling RF power and high-voltage pulse power.

  The physical properties of the DLC film vary depending on the type of gas used, the gas pressure, the applied voltage, etc., but a DLC film having excellent adhesion to the substrate, high hardness and a large film thickness is preferred. In the plasma-based ion implantation / deposition apparatus, it is preferable to form a film by a process of at least three steps. After cleaning the substrate surface, ion implantation is performed at a high voltage, and then methane, acetylene, toluene at a voltage lower than the carbon ion implantation voltage. It is preferable to form a DLC film by introducing a gas such as, and then form a DLC film at a lower voltage (several kV). This is because when the DLC film is formed with high energy, the carbon bond is recut and the DLC fine film structure is disturbed, so that it is difficult to obtain a hard and high-quality film and it is difficult to obtain the film formation speed. In particular, it is preferable to form a film with lower energy as the surface layer portion is obtained because a high-quality DLC film can be obtained. Thus, it has been found that the three steps of high energy ion implantation, medium energy DLC film formation, and low energy DLC film formation are useful for relaxation of residual stress in the DLC film and are advantageous for thick film formation.

Embodiments of the present invention will be described below.
First, a schematic configuration of a plasma-based ion implantation / deposition apparatus used in the surface treatment method for various substrates of the present invention will be described with reference to FIG. This apparatus comprises a vacuum chamber 3 containing a frame 2 on which a metal fiber fabric member 1 is set. The set stand also serves as an electrode for applying a negative voltage. The inside of the vacuum chamber 3 can be maintained at a predetermined degree of vacuum by the exhaust device 4. In this apparatus, a predetermined hydrocarbon-based gas is introduced through the introduction port 5 to form a hydrocarbon-based gas plasma and, if necessary, ion implantation of a metal-based element to improve the adhesion of the DLC film. An organometallic gas introduction source 6 is also provided.

  The apparatus further includes a high voltage negative pulse power source 7 and a radio frequency (RF) power source 8 for applying a high voltage negative charge to the metal fiber fabric member 1 having various shapes. The high voltage negative pulse power source 7 generates a negative charge having a predetermined energy, and applies a negative charge pulse to the metal fiber fabric member 1 through the high voltage feedthrough 9. This feed-through is connected to the set frame, and the set frame is in an electrically floating state with an insulator 10. Further, when forming the DLC, it is possible to supply the power from the high-voltage feedthrough 9 through the superimposing device 11 that superimposes the high-voltage pulse and the high frequency to form the supply gas into a plasma. A shield cover 12 is attached to the high voltage feedthrough 9 to protect the feedthrough 9.

  A metal fiber fabric member 1 as shown in the developed view of FIG. 1 is set on the set frame 2 of this apparatus. This is a metal fiber fabric member 1 having a side of 600 mm and a thickness of 0.03 to 0.06 mm. 9 sheets can be set. The metal fiber fabric member 1a is a stainless steel fabric as shown in the enlarged cross-sectional view 1d, and a part of the metal fiber fabric member 1a was sampled after the film formation. For those that are difficult to evaluate with a mesh, a stainless steel plate test piece and an evaluation silicon wafer 1c are attached so that the characteristics can be evaluated.

When a negative charge pulse is applied to these metal fiber fabric members, carbon ions in the plasma or ions such as CH, CHx, and C2 are attracted to the metal fiber fabric members, and carbon ions or hydrogen ions are implanted. Since ions are implanted by applying a negative charge pulse to the metal fiber fabric member, an electric field is generated along the shape of the member, even if the member is not a flat plate but an uneven solid shape, and is almost perpendicular to the surface. Carbon ions collide with each other. Therefore, even if the insulating plastic member has irregularities, carbon ions can be implanted into the entire plastic surface. At the same time, hydrogen ions are also ion-implanted, but it is known that hydrogen in the base material diffuses and degass after injection, and it is considered that the physical properties of the base material are not greatly affected. .

Carbon ion implantation is performed at a voltage of several kV or more, preferably 10 kV or more, but the DLC film is formed by mixing a mixture of hydrocarbon gases such as methane, acetylene, benzene, and toluene at an arbitrary ratio of 10 kV or less. The film is formed while applying a voltage of. This is because when the DLC film is formed at a high energy, the film structure of the DLC is disturbed by the collision energy of ions, and it is difficult to obtain a hard and high-grade film, and it is difficult to obtain a film formation speed. In particular, it is preferable to form a film with lower energy as the surface layer portion is obtained because a high-quality DLC film-coated article is obtained. It is preferable to use a film forming technique in which the voltage is gradually lowered from the high voltage side to the low voltage side by automatic control during film formation.
This will be described below based on examples.

  Using a plasma-based ion implantation / film formation apparatus as shown in FIG. 1, four metal fiber fabric members are set as shown in the developed view in the figure, and an SUS plate and film for measuring ion implantation depth are fixed to this fixed frame. A thickness evaluation silicon wafer was attached. In the experiment, a stainless mesh having a wire diameter of φ16 μm was used, and a sample such as an enlarged cross-sectional view was sampled after the DLC film formation, and the characteristic values such as tensile strength, elongation rate, rigidity rate, and friction coefficient were compared with the untreated sample. In the experiment, plasma was generated under the following conditions, and carbon ion implantation + carbon film was formed and evaluated.

The experimental conditions were evaluated by setting various parameters as follows, generating plasma, and performing carbon ion implantation + carbon film formation.
Material used: Stainless steel mesh wire diameter φ16μm
Type of gas used: Methane gas / acetylene gas mixture ratio: Methane gas 50 / acetylene 50
Pressure during injection and film formation: 0.5 Pa to 1.0 Pa
Injection energy: 10keV, 15keV, 20keV
Deposition energy: 10 keV → 2 keV
Injection time: 30 minutes Carbon film formation time: 180 minutes Applied frequency: 2000Hz

  Carbon ions were implanted into the stainless mesh with the energy of the above three conditions, and then the DLC film was formed using a methane / acetylene mixed gas while lowering the voltage. Since the pressure at the time of film formation fluctuates when the negative voltage or the film formation energy is changed, the pressure range at that time is shown, and the arrow of the film formation energy indicates that the experiment was performed while the voltage was reduced within the film formation time. The distribution of the implanted carbon element in the depth direction was evaluated by an Auger analyzer (AES), and the carbon implantation depth and amount (atomic concentration (%)) were obtained. In addition, for the evaluation of the physical properties of the stainless steel mesh substrate, it was cut out with a size of 150 × 10 mm, and the tensile strength, elongation rate, and rigidity rate of the mesh were measured with a tensile tester. Furthermore, in order to evaluate the slipperiness of the surface, the friction coefficient between the mesh and the steel ball was measured by a friction test by a ball and disk method. The DLC film thickness was determined by measuring the DLC film thickness on nine silicon wafers attached to the metal fiber fabric member fixing frame 1b, and the variation of the DLC film thickness was evaluated.

  FIG. 2 shows the result of analyzing the stainless steel mirror polished sample with respect to the ion implantation depth which is an important element of the present invention. The horizontal axis indicates the depth direction of the stainless material, the origin indicates the DLC film material, and the vertical axis indicates the proportion of the carbon element in the material. In the analysis, the DLC film was analyzed after thinning it beforehand by argon sputtering. As can be seen from FIG. 2, on the stainless steel surface, the carbon layer, which is the main component of the DLC film, is formed up to about 300 nm, and the vicinity of 330 nm is seen as the outermost surface portion of the stainless steel. From this, it can be seen that the carbon injection layer is a high concentration carbon layer from 380 nm to 450 nm. As a result, it can be seen that the higher the implantation energy, the deeper the carbon penetration depth, and the ion implantation into the interior. It can be seen that the carbon implantation depth is about 10 nm at 10 keV, 90 nm at 15 keV, and 120 nm at 20 keV. This shows that the higher the applied voltage before forming the DLC film, the deeper the carbon penetrates into the stainless material, indicating an inclined structure.

On the other hand, FIG. 3 shows the results of evaluation of characteristics of the stainless mesh, such as tensile strength, elongation, rigidity, and friction coefficient. As a result, the tensile strength of the untreated stainless steel mesh is 80 N / cm, whereas the tensile strength is increased by 5 to 10% by forming the DLC film. In addition, the elongation rate is 6.5% for the untreated sample, but when the DLC film is formed, the elongation decreases by 30 to 50% or more. As a result, the rigidity increases greatly by 20 to 35%. You can see that
Further, looking at the friction coefficient of the stainless steel mesh surface, the untreated mesh showed a high friction coefficient of 0.25, but the DLC film showed a low friction coefficient of 0.18 or less. Looking at the relationship with the ion implantation energy, it showed good properties such as tensile strength, elongation, rigidity, friction coefficient, etc. at a moderate implantation energy of about 15 kV.

  Furthermore, as a result of evaluating the uniformity of the DLC film thickness with the sample formed simultaneously with the stainless mesh, as a result of measuring nine points under one condition as shown in FIG. 3, the average film thickness of 1 μm is ± 0.2. It was found that DLC film formation was possible with an error range of μm. This indicates that the film can be formed stably regardless of the ion implantation energy.

  Although not described in the experimental example, as a result of the same experiment and evaluation with respect to the nickel alloy mesh, carbon ion implantation was confirmed up to about 130 nm with 10 keV energy, and further DLC film formation with acetylene / toluene was formed. It was found that the later physical properties also showed the same surface physical properties as the stainless mesh. Thus, it became clear that pulsed ion implantation of carbon and subsequent DLC film formation are indispensable regardless of the metal material.

As described above, according to the method of the present invention, carbon ion implantation is performed from a hydrocarbon-based gas plasma to a metal fiber fabric member using a plasma-based ion implantation / film formation method, and at least hydrocarbon gas is added. DLC coated article with excellent tensile strength, rigidity (rigidity), deformation resistance, wear resistance, and slip resistance of metal fiber fabric member and its surface by forming DLC film while mixing and introducing one or more kinds It has been found that a processing method can be provided.

  Further, the DLC-coated article of the present invention has high surface hardness due to carbon ion implantation, and excellent wear resistance and corrosion resistance. Therefore, various semiconductor filters other than screen printing plates, food filtration filters, bio-related filters It is applicable to. Furthermore, the carbon ion implantation + DLC film forming technology of the present invention can increase not only tensile strength, rigidity (rigidity), deformation resistance, wear resistance, and corrosion resistance, but also contamination resistance, water repellency / release properties, The present invention can also be applied to industrial ceramic materials, metal material molded products, and the like, such as increasing the surface hardness of metal materials and ceramic materials other than the application of the present invention, and improving the functionality of lubricity and releasability.

It is the block diagram and member shape figure of the plasma base ion implantation and film-forming apparatus used for the metal fiber fabric member of this invention. It is a graph which shows the relationship between the carbon injection depth by the Auger analysis after carbon ion implantation to SUS304, and a carbon concentration. It is a table | surface which shows the mesh tensile strength, elongation rate, rigidity, a friction coefficient, and DLC film thickness distribution after carbon ion implantation + DLC formation to a stainless steel mesh.

Explanation of symbols

1 Semiconductor carrier material
2 frame
3 Vacuum chamber
4 Exhaust device
5 Hydrocarbon gas inlet
6 Organometallic gas inlet
7 High voltage negative pulse power supply
8 RF power supply
9 Feedthrough for high voltage
10 Insulator
11 Superimposing device shield cover

Claims (9)

A carbon gas plasma is generated in a vacuum of 0.1 to 10 Pa, a metal fiber fabric member made of stainless steel fiber or the like is exposed therein, and a high voltage negative pulse of 1 to 30 keV and 100 to 5000 cycles is applied to the member, A surface treatment method for a metal fiber fabric, characterized by injecting carbon ions into the surface of the metal fiber fabric member. A metal fiber woven member, which is an untreated product, is set in a vacuum of 0.1 to 10 Pa, and a hydrocarbon gas is introduced therein to generate plasma by supplying high-frequency power, and the metal fiber woven member is 1 to 30 keV, 500 A surface treatment method for a metal fiber fabric member, comprising applying a high-pressure negative pulse of ˜5000 cycles, ion-implanting carbon ions from the surface of the metal fiber fabric member, and then depositing a diamond-like carbon layer on the surface layer. As a hydrocarbon gas, a gas mainly composed of at least one selected from gases consisting of methane, acetylene, benzene, toluene and cyclohexanone, chlorobenzene, carbon difluoride, carbon tetrafluoride, etc. is used. 3. The surface treatment method for a metal fiber fabric member according to claim 2, wherein a DLC layer is formed after carbon ions are implanted. The surface treatment method for a metal fiber fabric member according to claim 2, wherein the applied voltage to at least the metal fiber fabric member is 10 keV or more and the carbon ion implantation time is 30 to 120 minutes. The surface treatment method for a metal fiber fabric member according to any one of claims 1 to 4, wherein the metal fiber fabric member is mainly composed of a metal member such as stainless steel, a titanium alloy, or a nickel alloy. 6. The surface treatment method for a metal fiber fabric member according to claim 5, wherein a carbon ion implanted layer is ion-implanted into the metal fiber member by 10 nm or more from the member surface layer. The surface treatment method for a metal fiber fabric member according to any one of claims 1 to 6, wherein carbon ions are implanted into the metal member, and the carbon concentration inside the member surface layer is 10 at% or more. 2. The metal fiber according to claim 1, wherein after the ion implantation of carbon ions on the surface of the metal fiber fabric member, a diamond-like carbon layer is continuously formed at least 1 μm or more so that the surface friction coefficient is 0.18 or less. A surface treatment method for a fabric member. A metal fiber woven article manufactured using the method according to claim 1.

Images