JP2004060741A - Diaphragm, diaphragm valve, and film forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm and a diaphragm valve capable of realizing high seal reliability, requiring low pressure for sealing of a valve seat portion, low output of a valve drive, and little danger of leak due to biting of particles into the valve seat portion, and to provide a film forming device forming significantly high quality. <P>SOLUTION: A film layer 12 of superelastic metal material is formed on a surface coming into contact with the valve seat. Preferably, the Young's modulus of the superelastic material is less than 3,000 kg/mm<SP>2</SP>, the film layer is preferably formed by a IBAD method, and the superelastic material is preferably of a Ti-group alloy. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
The present invention relates to a diaphragm, a diaphragm valve, and a film forming apparatus, and more particularly, to a metal diaphragm, a diaphragm valve, and a film forming apparatus used in an ultra-high-purity fluid line represented by, for example, a semiconductor / liquid crystal isolation line. [0002]
[Prior art]
FIGS. 4 and 5 show examples of the configuration of a generally used diaphragm valve structure.
[0003]
FIG. 4 shows a structure in which a resin is used for the valve seat 4, and the valve seat portion is sealed by pressing the resin valve seat 4 fixed to the body 1 with the diaphragm 3.
[0004]
FIG. 5 shows a structure in which a valve seat portion 2 is formed on a body 1 and a valve seat portion is sealed by pressing a valve seat portion 2 made of the same material as the body 1 with a diaphragm 3.
[0005]
However, the conventional example has the following problems.
[0006]
In the example shown in FIG. 4, since the resin is used for the valve seat 4, (1) the applicable range is narrow depending on the type and temperature of the fluid. (2) It takes a long time to remove moisture adsorbed on the surface. (3) Creep occurs in the valve seat 4, which affects the sealing performance.
[0007]
In the example shown in FIG. 5, since the valve seat portion 4 is made of the same metal as the body 1, the above-described problems depending on the material properties of the resin are remarkably improved. Requires a large force to seal the diaphragm with the diaphragm 2. (2) When the diaphragm 2 is pressed against the valve seat portion 4 to seal it, stress concentration may occur on the contact surface of the diaphragm 2 with the valve seat 4 even if a force within the elastic region is applied. The portion where the stress concentration occurs may cause plastic deformation. Therefore, even if it is removed, the deformation remains. As a result, the seal is incomplete and the reliability of the valve is impaired. (3) Since both the valve seat portion 4 and the diaphragm 2 are made of metal, particles of the metal may be generated due to contact between the two. The particles may bite into the valve seat 4. Leakage tends to occur when particles are caught. (4) Since both the valve seat portion 4 and the diaphragm 3 are made of metal, the contact surfaces (seal portions) of the two are hardly in perfect surface contact. In order to achieve perfect surface contact, it is necessary to reduce the surface roughness of the sealing surfaces of the valve seat portion 4 and the diaphragm 2. Advanced processing techniques are required to reduce the surface roughness. (5) In order to completely seal the valve seat portion 4, the diaphragm 2, and the seal, it is necessary to press the diaphragm against the valve seat portion 4 with a large pressing force. However, when a large pressing force is applied, the diaphragm undergoes plastic deformation, and even if the pressing force is removed, the plastic deformation remains, which eventually causes a leak. Gas cannot be supplied with stability or reliability without leakage. (5) Particles are mixed into a gas using portion (for example, a film forming apparatus), and the formed film becomes a film having poor characteristics including impurities.
[0008]
[Problems to be solved by the invention]
The present invention solves the above problems.
[0009]
An object of the present invention is to provide a diaphragm capable of improving the reliability of a seal.
[0010]
An object of the present invention is to provide a diaphragm that does not cause problems (corrosion resistance, temperature dependency of mechanical strength, moisture desorption time, creep) depending on the material properties of a resin.
[0011]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a diaphragm and a diaphragm valve which require only a small force for sealing a valve seat portion and can reduce the output of a valve driving portion.
[0012]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a diaphragm and a diaphragm valve which have a low risk of leakage due to a particle being caught in a valve seat portion.
[0013]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a diaphragm and a diaphragm valve that do not require advanced processing technology for a seal portion of a valve seat.
[0014]
An object of the present invention is to provide a film forming apparatus capable of forming a film with good quality.
[0015]
[Means for Solving the Problems]
The diaphragm according to the present invention is characterized in that a thin film layer of a superelastic metal material is formed on a surface in contact with the valve sheet.
[0016]
[Action]
In the present invention, a thin film layer of a superelastic metal material is formed on one surface.
Superelastic metal materials are metal materials that exhibit superelastic properties. Note that the metal material includes an alloy material. The superelastic property is a property in which even if a material is largely deformed, it returns to its original shape when a force is removed.
[0017]
When returning to the original shape, there are (1) a return along a stress-strain curve when a weight is added, and (2) a return in a loop. Note that “large deformation” is deformation that reaches plastic deformation in a conventional material.
[0018]
In the case where local stress concentration occurs, if the stress σ ₀ is within the elastic region, the local deformation does not remain even if the stress is removed in the related art. However, in the case where a stress concentration (stress σ ₁ ) exceeding the elastic region occurs, in the related art, local deformation remains even after removal. .
[0019]
On the other hand, in the present invention, stress concentration occurs, and no local deformation remains after the load is unloaded regardless of whether the stress is σ ₀ or σ ₁ . Therefore, a highly reliable valve function can be achieved.
[0020]
Further, the superelastic metal material has a low modulus of longitudinal elasticity. Therefore, the thin film layer contacts the valve sheet with a large contact area without applying a large force. That is, the sealing property is improved only by applying a small force.
[0021]
In addition, rubbing on the contact surface is reduced, and generation of particles is drastically reduced. As a result, it is possible to prevent the occurrence of leakage due to the entrapment of particles. In addition, since the mixing of particles into the gas is drastically reduced, a high-purity gas can be supplied to the gas use section. In particular, when the gas is used in a film forming apparatus such as a semiconductor, a high quality film can be formed.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a diaphragm according to an embodiment of the present invention.
[0023]
The diaphragm 3 has a thin film layer 12 made of a superelastic metal material formed on the concave side (the seal surface side with the valve sheet). This diaphragm is used in the diaphragm valve shown in FIG. Note that FIG. 2 is the same as the structure shown in FIG.
[0024]
(Base of diaphragm)
The thin film layer 12 is formed on the base 11. It is preferable to use a material other than the superelastic metal material as the material of the base 11. For example, a substrate made of a Ni-Co alloy is preferable. When a substrate made of a Ni—Co alloy is used, high rigidity, high durability, and high corrosion resistance can be obtained.
[0025]
(Elastic coefficient)
It is preferable that the longitudinal elastic modulus of the thin film layer 12 is 5000 kg / mm ² or less. 4000 kg / mm ² or less is more preferable, and 3000 kg / mm ² or less is further preferable. However, if it is less than 100 kg / mm ² , the strength becomes weak, so the lower limit is preferably 100 kg / mm ² . By controlling the thickness to 5000 kg / mm ² or less, the thin film layer 12 has good followability to the valve sheet. In other words, the contact area with the valve seat portion is increased by only applying a smaller force, and the sealing characteristics are further improved.
[0026]
The control of the longitudinal elastic coefficient may be performed by changing the composition of the metal material. For example, in the case of a Ti-based alloy, the longitudinal elastic modulus can be increased by increasing the addition amount of Al and V. In addition to the composition control, the longitudinal elastic modulus may be controlled by annealing. For example, the temperature and time may be changed to a desired longitudinal elastic modulus. The specific material may be determined in advance by experiments.
[0027]
(Method of forming thin film layer)
The thin film layer 12 may be formed by bonding a film made of a superelastic metal material on the base 11.
[0028]
In order to have good adhesion to the substrate 11 and to form a dense thin film layer, it is preferable to form it by the IBAD method (Ion Beam-Assist-Deposition).
[0029]
FIG. 3 shows a conceptual diagram of the IBAD method. In this method, when the thin film layer 32 is formed on the substrate 31 by an electron beam evaporation method or a class ion beam evaporation method, a film is formed by irradiating an ion beam from an ion gun disposed in an evaporation tank. is there.
[0030]
When the IBAD method is used, the adhesion is better and the dense thin film layer 32 can be formed on the base 31 as compared with the case where the IBAD method is used.
[0031]
For example, in the case of a Ti-based alloy, a thin film layer formed by the IBAD method has superelastic properties.
[0032]
(Thickness of thin film layer)
The thickness of the thin film layer is preferably from 0.1 μm to 10 μm. When formed by the IBDA method, the thickness is preferably 3 μm or less, more preferably 1 μm or less. When the thickness is 0.1 μm or more, breakage due to repeated use can be prevented. In particular, a thin film formed by IBAD has high fatigue strength even at 0.1 μm. Even if the thickness exceeds 10 μm, the effects of the present invention such as the sealing property are saturated. Therefore, from the viewpoint of cost, the thickness is preferably 10 μm or less.
[0033]
(Composition of superelastic material)
As the superelastic material, a Ti-based alloy is preferable. It is preferable to contain one or more of Nb, Ta, V, Zr, Hf, O, and N based on Ti. Further, C may be contained. It is preferable to do so by including at least one of Nb, Ta, Va, Zr, Hf, O, N, and C. Further, C may be contained.
[0034]
Components other than Ti in the Ti-based alloy include, for example, Al of 1 to 10% by weight.
[0035]
(Diaphragm valve)
As a diaphragm valve using the above-mentioned diaphragm, the diaphragm of the present invention may be used as the diaphragm in the basic structure shown in FIGS. In particular, the effect of the present invention is remarkable in a diaphragm valve in which the valve seat portion 2 is made of metal.
[0036]
In the structure shown in FIG. 4, the diaphragm according to the present invention may be used even when the valve seat 4 is made of metal instead of resin.
[0037]
(Deposition equipment)
The diaphragm valve according to the present invention is suitably used for a film forming apparatus. In particular, it is suitably used for a film forming apparatus for forming a semiconductor element or a liquid crystal element, which requires supply of a high-purity gas and requires improvement in throughput.
[0038]
【The invention's effect】
The present invention has the following effects.
[0039]
(1) Since no resin is used, problems (corrosion resistance, temperature dependence of mechanical strength, moisture desorption time, creep) that do not depend on the material properties of the resin do not occur. Due to the effect of the thin film layer of the superelastic metal material formed in the above, the power required for sealing the valve seat portion can be small, and the output of the valve drive unit can be reduced. Due to the effect of the thin film layer of the superelastic metal material formed on the side of ()), the danger of the occurrence of leakage due to the bite of the particles into the valve seat portion is reduced.
(4) Due to the effect of the thin layer of the elastic metal material formed on the concave surface of the diaphragm (the surface on which the valve seat is sealed), an advanced sealing technique is not required.
(5) Since the switching can be performed with a small output, the introduction of the gas into the film forming chamber can be quickly switched, and the introduction and the stop of the gas can be performed at a desired timing. A good film can be formed.
[0040]
In addition, since particles can be prevented from being mixed, a film with good quality can be formed.
[Brief description of the drawings]
FIG. 1 is a sectional view and an enlarged view of a diaphragm according to an embodiment of the present invention.
FIG. 2 is a sectional view of a diaphragm valve according to an embodiment of the present invention.
FIG. 3 is a conceptual diagram of an example of an apparatus for forming a thin film layer of a diaphragm according to an embodiment of the present invention.
FIG. 4 is a sectional view of a diaphragm valve according to a conventional example.
FIG. 5 is a sectional view of a diaphragm valve according to another conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Body 2 Valve seat part 3 Diaphragm 4 Valve seat 11 Base 12 Thin film layer 31 Base 32 Thin film layer 33 Reaction gas 34 Evaporation source,
35 ion gun

Claims (11)

A diaphragm, wherein a thin film layer of a superelastic metal material is formed on a surface in contact with a valve sheet. The modulus of longitudinal elasticity of superelastic material, the diaphragm according to claim 1, wherein a is 5000 kg / mm ² or less. The diaphragm according to claim 1, wherein the thin film layer is a thin film layer formed by an IBAD method (Ion Beam-Assist-Deposition). The diaphragm according to any one of claims 1 to 3, wherein the superelastic material is a Ti alloy. The diaphragm according to claim 4, wherein the Ti alloy contains at least one of Nb, Ta, Va, Zr, Hf, O, and N. The diaphragm according to claim 4, wherein the Ti alloy contains Co. The diaphragm according to any one of claims 1 to 6, wherein the base portion on which the thin film layer is formed is made of a Ni-Co alloy. A diaphragm valve using the diaphragm according to any one of claims 1 to 7. 9. The diaphragm valve according to claim 8, wherein the valve seat is made of metal. A film forming apparatus comprising the diaphragm valve according to claim 8. The film forming apparatus according to claim 10, wherein the film forming apparatus is an apparatus for forming a semiconductor element and a liquid crystal element.

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