JPH05301066A - Powder beam coating method - Google Patents

Abstract

PURPOSE:To enable a coating to a material to be worked in a short time in atmosphere at a room temp. and to enable a dense coating with excellent adhesion. CONSTITUTION:In a powder beam coating method by injecting powdery fine particles 15 through a nozzle to the surface of the material to be worked 36 to form a fine particle coating film on the surface of the material to be worked 36, the fine particles 15 injected through the nozzle is embedded into the surface of the material 36 to form a coating film of the fine particles 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention ejects powdery fine particles onto a surface of an object to be processed such as a glass substrate or a semiconductor substrate at a high speed from an injection nozzle to form a film of particles (so-called deposition) on the surface of the object to be processed. ) Of the powder beam coating method.

[0002]

2. Description of the Related Art Conventionally, in manufacturing semiconductor integrated circuits, printed wiring circuits, and various functional elements such as magnetic heads, various fine processings have been required, and advanced thin film forming techniques have been required.

Under such circumstances, researches on processing techniques have been advanced in various fields. For example, as a method for coating the surface of a semiconductor wafer with ceramics, glass or the like, ions of an inert gas are accelerated in a target in a vacuum. Then, the target is knocked out, and the target is knocked out and deposited on the substrate to form a thin film, or a method using a vacuum device such as an ion plating method, or a material for film formation, for example, a ceramic powder is used. There is a thermal spraying method in which it is melted by heat of plasma or a burner in the air or under reduced pressure and is blown to form a thin film.

[0004]

However, in the method using the above-mentioned vacuum device and the thermal spraying method, the temperature of the work piece may become high during the coating process of the coating, and the work piece may be deformed or the work piece may be deformed. If the surface of the processed product is not roughened, there is a problem that the adhesiveness of the coating is reduced. Further, in the case of using the above-mentioned vacuum device, there is a problem that the coating process takes time and the coating process becomes impossible when the workpiece is large. Further, in the case of the above-mentioned thermal spraying method, there is a problem that pores (so-called bubbles) are generated in the coating film, the film quality of the coating film is deteriorated, and the productability is impaired.

Therefore, as an alternative processing method to the above-mentioned conventional coating technique, a processing method in which powdery fine particles are sprayed from a spray nozzle at a high speed to form a film on the surface of a workpiece is disclosed in, for example, Japanese Patent Laid-Open No. 231096/1993. It is proposed in the gazette and the like.

As described above, the present invention forms a coating film on the surface of a work piece by spraying fine particles to improve the corrosion resistance and wear resistance of the work piece surface. The purpose is to obtain a beam coating method.

[0007]

In order to achieve the above-mentioned object, the powder beam coating method according to the present invention is a method of spraying powdery fine particles from a nozzle at high speed onto the surface of an object to be processed such as a glass substrate or a semiconductor substrate. In a powder beam coating method in which a fine particle coating is formed on the surface of a workpiece, the fine particle sprayed from a nozzle is embedded in the surface of the workpiece to form a fine particle coating. ..

[0008]

In the powder beam coating method according to the present invention as described above, fine particles are applied to the surface of an object to be processed such as a glass substrate or a semiconductor substrate from a nozzle by, for example, 100 to 100
By injecting and colliding at a high speed of 300 m / sec, a part of the fine particles or the whole of the fine particles are embedded in the surface of the workpiece, and a fine particle coating film is formed on the surface of the workpiece.

[0009]

Embodiments of the powder beam coating method according to the present invention will be described below with reference to the drawings. First, a block diagram of a processing apparatus for carrying out the method of the present invention will be described with reference to FIG.

The processing apparatus used in this example is roughly divided into an air compressor 1 for supplying compressed air, a mixing chamber 2 for mixing compressed air delivered from the air compressor 1 with powdery fine particles, and compressed air. At the same time, it is composed of a processing chamber 3 for injecting fine particles onto a workpiece and an air blower 4 for collecting and sucking fine particles from the processing chamber 3.

An air supply pipe 5 is led out from the air compressor 1, and the air supply pipe 5 is further branched into a first supply pipe 6 and a second supply pipe 7, which are respectively connected to the mixing chamber 2. ing. An adjusting valve 8 for adjusting the pressure of the compressed air supplied to the mixing chamber 2 and a solenoid valve 9 for controlling the supply of the compressed air to the mixing chamber 2 are provided in the middle of the air supply pipe 5. An adjusting valve 10 that adjusts the flow rate of the compressed air to the second supply pipe 7 is provided in the middle of the second supply pipe 7.

On the other hand, a fine particle supply unit 11 is provided above the mixing chamber 2, and the lid 12 of the supply unit 11 is opened to supply the fine particles.

The bottom of the supply unit 11 has a conical shape, and an inlet 11a for the mixing chamber 2 is provided in the center thereof, and a conical supply valve 1 fitted into the inlet 11a.
3 is provided. The supply valve 13 is arranged so as to penetrate through the central portion of the lid body 12, and a coil spring 14 is interposed between the locking portion 13a provided at the base end portion of the lid body 12 and the lid valve 12 in the drawing. It is biased upward. Therefore, normally, the peripheral surface of the conical portion 13b is closed by closely contacting the input port 11a, and the conical portion 13b is pressed by pressing the supply valve 13 against the coil spring 14 as necessary. The state of close contact with the charging port 11a is released, and the fine particles in the supply unit 11 are dropped into the mixing chamber 2.

The mixing chamber 2 is a cylindrical container in which fine particles are stored. The bottom of the mixing chamber 2 is also conical, and a cermet (a porous plate having innumerable fine holes formed by sintering metal powder) on the bottom surface thereof.
And a disc-shaped filter 16 made of
The first supply pipe 6 of the air compressor 1 is connected to the back side of the filter 16. Therefore, the compressed air supplied to the first supply pipe 6 is introduced into the mixing chamber 2 via the filter 16.

A plurality of vibrating means 17 are provided on the slope around the filter 16. This vibrating means 17
Is a so-called bimorph composed of, for example, a pair of upper and lower piezoelectric elements and electrodes, and is arranged in an annular shape so that its free end faces above the filter 16, and the base end portion has a conical shape of the mixing chamber 2. It is fixed on the slope of.

The vibrating means 17 can vibrate its free end in the vertical direction by applying a predetermined AC voltage, for example, and mechanically disperse the fine particles 15 and agitate with the compressed air from the filter 16. An air vibration effect of mixing can be imparted. still,
The frequency of the applied AC voltage is, for example, 200 to 400.
A high frequency of about kz may be used, and it is desirable that the resonance frequency be substantially equal to the bimorph resonance frequency. Further, it is more effective to reverse the phase of vibration of the vibrating means 16.

Further, in this embodiment, the rubber sheet 18 is adhered so as to cover the half of the vibrating means 17 on the proximal end side, so that it is possible to prevent fine particles from entering the lower side of the vibrating means 17 and inhibiting the vibration. ing.

At the center of the filter 16, a delivery pipe 19 penetrating the bottom of the mixing chamber 2 is erected so that one end opens into the mixing chamber 2 and is agitated and dispersed by compressed air in the mixing chamber 2. The fine particles 15 are delivered. The tip portion 7a of the second supply pipe 7 is inserted in the middle of the delivery pipe 19, and the delivery pipe 19 is caused by the negative pressure generated by the air flow of the compressed air supplied from the second supply pipe 7. The fine particles 15 are sucked in, mixed with compressed air, and sent out.

Further, the delivery pipe 19 is extended to the processing chamber 3, a nozzle 20 is provided at the tip end thereof, and a vibrating means 21 is provided in the middle portion thereof, and is deposited on the middle portion of the delivery pipe 19. To prevent that.

The delivery pipe 19 is made of, for example, a flexible tube such as a urethane tube, a nylon tube, and a vinyl tube, and is arranged so as to be gently bent while avoiding sudden bending. In addition, the connecting portion of each pipe is structured so as to avoid air traps by avoiding steps or the like, so that clogging due to accumulation of fine particles is prevented in advance. Further, on the bottom surface of the mixing chamber 2, an air outlet 22 is opened around the delivery pipe 19, and a part of the compressed air supplied from the first supply pipe 6 is ejected from the air outlet 22. However, a turbulent air flow is generated in the vicinity of the inlet 19a of the delivery pipe 19, and the fine particles 15 are strongly stirred.

Inside the mixing chamber 2, there is further provided a stirring mechanism 24 having a rotating shaft 23 fixed to the bottom surface of the supply valve 13. The stirring mechanism 24 includes an arm portion 24a extending from the rotating shaft 23, a frame body 24b made of a thin metal wire, and the like.
The brush 24 provided along the lower edge of the frame body 24b
It has a function of crushing the lumps of the fine particles 15 aggregated in the mixing chamber 2 by driving the rotating shaft 23.

A dust collector 25 is provided above the delivery pipe 19 of the mixing chamber 2, and the bottom of the dust collector 25 has a trapezoidal shape facing the inlet 19a of the delivery pipe 19. A recess 25a is formed. Dust collector 2
The upper half of 5 is a filter 25b made of a porous material, and is connected to the blower 4 via a lead-out pipe 26. An electromagnetic valve 27 for adjusting the flow and amount of exhaust gas and an exhaust amount adjusting valve 28 are provided in the middle of the outlet pipe 26.

The blower unit 4 has a filter 29 and a suction fan 30 inside, and the suction fan 30 allows the filter 2 to pass through.
Air is drawn from the outlet pipe 26 through the exhaust port 31
It is more exhausted. Therefore, the exhaust gas from the inside of the mixing chamber 2 is cleaned by the filter 29 and discharged to the outside. Further, the fine particles removed by the filter 29 are stored in a reservoir 32 provided below the filter 29. In addition, a moisture absorbing means 33 such as silica gel and a heating means 34 such as a heater are provided on the upper part of the mixing chamber 2, and a heater 35 is further wound around the mixing chamber 2 so that the fine particles in the mixing chamber 2 are wound. 15 is kept dry to prevent agglomeration.

On the other hand, the processing chamber 3 is provided with a nozzle 20 attached to the tip of the feed pipe 19 from the mixing chamber 2, and a rotary table 37 for mounting the workpiece 36 is provided facing the nozzle 20. ing. The rotary table 37 has a mesh shape for preventing, for example, the side surface of the workpiece from being carelessly processed due to the fine particles being ejected being reflected by the rotary table 37, and is rotated by the motor 38. It is designed to be.

The periphery of the rotary table 37 is covered with an intake box 39, and the fine particles 15 entering the processing chamber 3
Is prevented from scattering. When the particles are scattered in the processing chamber 3, for example, there is a risk that the particles 15 leak to the outside when an operator opens the door of the processing chamber 3, and the efficiency of collecting the particles 15 is also reduced.

The bottom of the processing chamber 3 is also conical and is provided with a return pipe 40. The return pipe 40 together with the return pipe 41 of the intake box 39 is covered.
It is led to the supply unit 11 via 2. In addition, processing room 3
A vibrating means 42 made of a bimorph or the like is also provided at the bottom of the device, so that the falling fine particles 15 can be quickly discharged by air vibration.

At the other end of the lid 12, an exhaust pipe 43 connected to the exhaust fan 4 together with the outlet pipe 26 is laid, and a cylindrical partition plate 44 hangs down. Therefore, the fine particles collected through the return pipes 40 and 41 are roughly dispersed according to the same principle as that of the cyclone by passing through the detour circuit by the partition plate 44.
It is dropped into 1. On the other hand, unnecessary air is exhausted from the blower 4 through the exhaust pipe 43. An electromagnetic valve 45 for controlling the flow of exhaust gas is provided in the middle of the exhaust pipe 43.

The processing apparatus configured as described above operates as follows. First, the compressed air sent from the air compressor 1 is branched into a first supply pipe 6 and a second supply pipe 7, and the compressed air branched into the first supply pipe 6 is a filter 16 or an air outlet. 22
Flows into the mixing chamber 2. At this time, when the compressed air passes through the fine particles 15, the fine particles 15 are agitated by a so-called air vibration effect, and a part of the fine particles 15 is collected by the dust collecting recess 25a of the dust collector 25 near the inlet 19a of the delivery pipe 19. ..

At the time of stirring the fine particles 15, mechanical dispersion by the vibrating means 17 is also performed, and the air vibration effect is effectively maintained. Further, the solenoid valve 2 provided in the middle of the outlet pipe 26 connected to the dust collector 25
7 and the exhaust pipe 4 connected to the lid 12 of the supply unit 11.
The solenoid valve 45 provided in the middle part of 3 is controlled so that the open / closed state is reversed at a constant cycle, and the fine particles 15 in the mixing chamber 2 are further disturbed by the pressure difference due to these open / close operations. ing. At this time, the displacement control valve 2
When the amount of exhaust gas from the inside of the mixing chamber 2 is reduced by 8 to a certain amount, the pressure difference becomes small, and the fine particles 15 are almost constantly injected even if a periodic opening / closing operation is performed.

On the other hand, the compressed air dispersed in the second supply pipe 7 is fed straight into the delivery pipe 19 and is negatively pressured by the air so that the inlet 19 is formed.
The fine particles 15 collected in the vicinity of a are sucked and mixed with the compressed air in the delivery pipe 19. Then, this mixture of compressed air and fine particles is jetted from the nozzle 20 through the delivery pipe 19 and sprayed on the processed surface of the workpiece 36 to form a film of fine particles on the processed surface. The used fine particles are returned to the supply unit 11 via the return pipes 40 and 41 and reused.

Here, the kind of fine particles and the principle of coating fine particles as a coating on the processed surface of the workpiece will be described. The fine particles are made of ceramics or glass. Specifically, ceramics include silicon carbide, alumina,
It is made of boron carbide, diamond or the like, and the glass is made of quartz, soda glass, lead glass or the like. The particle size of these particles is ultrafine particles of 0.1 to 2 μm. Further, as the workpiece, stainless steel, copper, aluminum, titanium, or the like is used.

The fine particles ejected from the nozzle 20 together with the compressed air are processed at a high speed of 100 to 300 / sec.
6 is made to collide with the machining surface, and the colliding fine particles are embedded in the machining surface to form a so-called coating film on the machining surface.

More specifically, the fine particles pulverized to have a particle size of 0.1 to 2 μm have an uneven outer shape, and therefore the fine particles 15 are generated when they collide with the work surface.
The corners of the particles are chipped off, and as shown in FIG. 2a, a part 15a of the chipped particles contributes to embedding.

Further, even if the particle size is 0.1 to 2 μm, the spherical particle produced by evaporation or synthesis does not have chipping even if it collides with the processing surface. Therefore, as shown in FIG. 2b. The entire fine particles 15 contribute to embedding.

Further, as a method of selectively applying a film of fine particles on the processed surface, as shown in FIG. 3, by covering the processed surface other than the portion where the film is formed with a mask 46, the selected surface of the processed surface is selected. A coating of the fine particles 15 can be formed.

On the other hand, the embedding speed of the fine particles in the processed surface differs depending on the angle (θ) of the nozzle 20 with respect to the processed surface, as shown in FIG. That is, as can be seen from the graph shown in FIG. 5, it is fastest when the nozzle 20 is at a right angle (so-called θ = 0 °) to the processed surface, and becomes slower as the angle θ increases.

Further, the embedding depth of fine particles into the processed surface is saturated at 1 to 2 μm, and the embedding amount of fine particles depends on the particle diameter of the fine particles. For example, if the particle size is 0.1μ
If it is less than m, it will not be embedded in the processed product, and if it is more than 2 μm, the processed surface will be destroyed. Therefore, as for the relationship between the particle diameter of the fine particles and the embedding amount, the particle diameter is preferably in the range of 0.1 to 2 [mu] m as shown in FIG.

FIG. 7 shows, by way of example, silicon carbide (Si) on a machined surface of a metal made of an alloy of nickel (Ni) and phosphorus (P).
C) is a graph of composition analysis (Auger analysis) of the metal surface before embedding the fine particles, and FIG. 8 is a graph showing composition analysis of the processed surface after embedding the silicon carbide fine particles. In both graphs, the horizontal axis represents the time taken to grind the surface of the machined surface by sputtering, which corresponds to the depth from the surface of the machined surface, and 1 minute is a depth of about 6Å. According to this, before embedding silicon carbide in FIG. 7, as the surface of the metal is sputtered, most of the metal components of Ni and P are present, and O, C and Si contained in this metal component.
The C component has a negligible value. On the other hand, when the silicon carbide shown in FIG. 8 is embedded, the SiC component has a depth of 480Å (80
It can be understood that it exists on the processed surface even if it becomes). This indicates that the silicon carbide film is surely formed on the surface of the processed surface. Needless to say, the hardness of the fine particles is higher than the hardness of the work piece because the fine particles are embedded and coated on the processed surface of the metal.

Further, when fine particles are embedded and coated on the processed surface of the metal, the metal surface is discolored by the pigment of the fine particles. For example, when coating alumina or glass,
It becomes transparent or white, but becomes green-black in the case of silicon carbide. Therefore, it is possible to visually confirm that the fine particles are embedded and coated on the processed surface by the color of the surface of the processed surface.

As described above, according to the powder beam coating method of the present invention, fine particles such as ceramics or glass ejected from the nozzle 20 are made to collide with the work surface of the workpiece 36, and the fine particles are embedded in the work surface to form a film. Since the coating method is used, the coating can be performed in the air and at room temperature, not in a vacuum atmosphere.Therefore, the workpiece is not affected by the temperature at all, and therefore the workpiece is deformed. Since it does not impair the product properties, it is suitable for coating precision parts that are resistant to thermal deformation.

Moreover, since coating can be performed in a short time, workability and productivity can be improved. In addition, since the coating by embedding fine particles has a dense composition and good adhesion, the corrosion resistance and abrasion resistance can be greatly improved. Furthermore, it is possible to coat a large workpiece and also to coat a curved workpiece.

The present invention is not limited to the embodiments described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention.

[0043]

As described above, according to the powder beam coating method of the present invention, the fine particles ejected from the nozzle are made to collide with the processed surface of the workpiece, and the fine particles are embedded in the processed surface to form a coating film. Since the method is used, coating can be performed in the air and at room temperature, not in a vacuum atmosphere, so the work piece is not affected by the temperature at all, and as a result, the work piece is deformed and product properties are improved. It is suitable for coating precision parts that are resistant to thermal deformation without deteriorating heat resistance.

Further, since coating can be performed in a short time, workability and productivity can be improved. In addition, the coating by embedding fine particles has a dense composition and good adhesion, so the corrosion resistance and wear resistance can be greatly improved, and the coating of large workpieces is possible, and the curved surface shape is also possible. There is an effect that it is possible to coat the workpiece.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a processing apparatus used in a powder beam coating method of the present invention.

FIG. 2 is a diagram for explaining a principle that fine particles are embedded in a processed surface.

FIG. 3 is a cross-sectional view of a work piece on which fine particles are selectively coated.

FIG. 4 is a diagram for explaining a tilt of a nozzle with respect to a processed surface.

FIG. 5 is a graph for explaining the relationship between the nozzle inclination and the particle embedding speed.

FIG. 6 is a graph for explaining the relationship between the particle size of fine particles and the particle embedding speed.

FIG. 7 is a graph of a composition of components at the time of processing surface sputtering before silicon carbide burying coating.

FIG. 8 is a graph of a composition of constituents at the time of processing surface sputtering after silicon carbide burying coating.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air compressor 2 Mixing chamber 3 Processing chamber 4 Exhaust fan 15,15a Fine particles 20 Nozzle 25 Powder collector 36 Workpiece 46 Mask

Claims (3)

[Claims] 1. A powdery fine particle is jetted at high speed from a nozzle onto the surface of a workpiece such as a glass substrate or a semiconductor substrate,
In the powder beam coating method for forming the fine particle coating on the surface of the workpiece, the fine particle sprayed from the nozzle is embedded in the surface of the workpiece to form the fine particle coating. Powder beam coating method characterized in that 2. The powder beam coating method according to claim 1, wherein the particle size of the fine particles is 0.1 to 2 μm. 3. The powder beam coating method according to claim 1, wherein the fine particles are made of ceramics or glass.