JP2023156213A - Composite metal seal with low fastening force - Google Patents

Abstract

To provide a metal seal with high reliability and low fastening force.SOLUTION: A composite metal seal structure is configured such that a metal seal with low fastening force having a high-temperature corrosive gas resistance characteristic is arranged on an inner peripheral side of a rubber O-ring seal having a high-temperature resistance characteristic; sealing performance between a surface of a member to be sealed and a seal surface is the same as before with the rubber O-ring seal; reliability of sealability is secured with the rubber O-ring seal; and although less reliable in sealability than the rubber O-ring seal, the metal seal with low fastening force has a reliable high-temperature corrosive gas resistance characteristic and prevents a high-temperature corrosive gas from entering the rubber O-ring seal side.SELECTED DRAWING: Figure 7

Description

The present invention relates to a composite metal seal with low clamping force.

In semiconductor manufacturing equipment, its gas exhaust pumps, and exhaust gas abatement equipment, large amounts of high-temperature corrosive gas or cleaning gas are introduced and exhausted due to further miniaturization and three-dimensionalization in recent semiconductor manufacturing processes. The need is increasing. Therefore, the seals used in these devices are required to have both high temperature resistance and corrosive gas resistance. There is an increasing demand for low tightening force metal seals that can be sealed by force. However, existing low-tightening-force metal seals suffer from misalignment of the sealing surface due to changes in the state and temperature of the sealing surface, as well as tightening caused by differences in thermal expansion coefficients between the sealing material and the material to be sealed or the tightening bolt material. In order to cope with force fluctuations, a high-precision surface finish on the sealed surface and a larger tightening force than rubber O-ring seals are required. A metal seal with a low tightening force equivalent to that of a seal has not been achieved.

As shown in product catalogs 1, 2, and 3, existing low-tightening force metal seals can be sealed with low tightening force by having a special shape or by narrowing the area of the seal part that comes into contact with the sealing surface. We are commercializing metal seals. However, since the mechanism seals in a narrow area of the metal surface and the tightening force is weak, the sealing surface may shift due to changes in the condition or temperature of the sealing surface, and furthermore, the sealing material and the material to be sealed or the tightening bolt material may Due to variations in clamping force due to differences in thermal expansion coefficients, its sealing performance is much less reliable than that of rubber O-ring seals.

literature

Product catalog 1

Product catalog 2

E-shape metal seal from Technologies Group

Product catalog 3

U-shaped metal seal from Mitsubishi Cable Industries, Ltd.

Application patent document 1

Patent application 2020-100469

The reliability of existing low tightening force metal seals is low because in order to achieve low tightening force, only a narrow protruding area of the metal surface is brought into contact with the surface to be sealed for sealing. In the case of a rubber O-ring seal, the rubber O-ring seal surface follows the unevenness of the sealed surface, and the sealing surface is a wide area, so there is a possibility that the sealing surface may shift due to some unevenness of the sealing surface or temperature changes. The sealing performance can be maintained regardless of fluctuations in the tightening force caused by the difference in thermal expansion coefficient between the sealing material and the material to be sealed or the tightening bolt material. Therefore, metal seals and rubber O-ring seals have their respective advantages, such as metal seals that can withstand high-temperature corrosive gases, and some seal surface irregularities and deviations of the seal surface due to temperature changes. We are considering a seal that combines the reliability of a rubber O-ring seal that can maintain sealing performance regardless of fluctuations in tightening force caused by differences in thermal expansion coefficients of tightening bolt materials. Here, a low-tightening force metal seal that is resistant to high-temperature corrosive gas is placed on the side that comes into contact with the high-temperature corrosive gas, and a reliable rubber O-ring seal made of high-temperature-resistant material is placed on the outside. It is a biasing force composite metal seal, and even if there is some gas leakage in the low clamping force metal seal, the reliability of the sealing performance is maintained throughout the low clamping force composite metal seal. Therefore, the challenge is how to create a compact, low-tightening-force composite metal seal that can be applied to conventional seal grooves.

In order to solve the above problem, a low tightening force metal seal with high temperature corrosive gas resistance is placed on the inner circumference side (high temperature corrosive gas side) of a rubber O-ring seal with high temperature resistance. The sealing performance between the seal surfaces is the same as before with the rubber O-ring seal, and the reliability of the sealing performance is ensured by the rubber O-ring seal.Although the reliability of the sealing performance is lower than that of the rubber O-ring seal, it is definitely resistant to high temperatures. A low-tightening-force metal seal with corrosive gas properties and a low-tightening-force composite metal seal structure that prevents high-temperature corrosive gas from entering the rubber O-ring seal side. The elastic force of the low tightening force metal seal is determined by a structure in which a part of the outer rubber O-ring seal is contained within the inner low tightening force metal seal, and the elastic force of the entire low tightening force metal seal is determined by the elastic force of the entire low tightening force metal seal. Set almost the same as O-ring seal. Here, due to the low reliability of the sealing performance of the inner low-tightening force metal seal, high-temperature corrosive gas leaks to the rubber O-ring seal side over time, but the amount of gas leaked is limited to the amount due to direct contact with the high-temperature corrosive gas. Compared to other low-tightening force metal seals, the tightening force is essentially zero, resulting in a low-tightening composite metal seal that does not affect the reliability of the rubber O-ring seal.

The low-tightening-force composite metal seal, consisting of a low-tightening-force metal seal and a rubber O-ring seal, has a shape that fits into the conventional rubber O-ring seal groove, so it is necessary to change the design of the conventional seal structure. It can be used as a seal to upgrade the high temperature corrosive gas resistance of existing equipment.

By placing a low-tightening-force metal seal with excellent high-temperature and corrosion resistance on the inside of the conventional rubber O-ring seal, that is, on the side where high-temperature corrosive gas flows, a low-tightening-force metal seal with excellent high temperature and corrosion resistance is installed. There are no adverse effects due to reactions with surfaces or gases generated from the sealing surfaces.

In addition, by placing a low-tightening force metal seal inside the conventional rubber O-ring seal, the amount of gas released from the rubber O-ring seal into the chamber is reduced, so the rubber O-ring seal It can also be used as a seal for semiconductor manufacturing equipment and analytical equipment that do not want the entry of polymer gases generated by other materials.

製品カタログ２のＥ形状低締付力メタルシール 製品カタログ３のＵ形状低締付力メタルシール 本発明の第一の実施例の低締付力複合メタルシール 本発明の第二の実施例の低締付力複合メタルシール 本発明の第三の実施例の低締付力複合メタルシール 本発明の第四の実施例の低締付力複合メタルシール

E-shape low tightening force metal seal in product catalog 2 U-shaped low tightening force metal seal in product catalog 3 Low clamping force composite metal seal of the first embodiment of the present invention Low clamping force composite metal seal of the second embodiment of the present invention Low clamping force composite metal seal of third embodiment of the present invention Low clamping force composite metal seal according to the fourth embodiment of the present invention

耐高温腐食ガスに対応するシールも製品化されているが、被シール面との接触部分が非常に狭く締付力が弱いため、シール表面の状態変化や温度変化によるシール面のずれ、更には、シール材と被シール材や締付ボルト材の熱膨張率の差からくる締付力の変動により、そのシール性能の信頼性はゴムＯ－リングシールに比べるとはるかに低くなっている。Embodiments of the present invention will be described below with reference to the drawings. Figures 1, 2, and 3 are C(+

Seals that are resistant to high-temperature corrosive gases have also been commercialized, but since the contact area with the sealed surface is very narrow and the tightening force is weak, the seal surface may shift due to changes in the condition or temperature of the seal surface, and even worse. The reliability of the sealing performance is much lower than that of rubber O-ring seals due to fluctuations in the tightening force caused by the difference in thermal expansion coefficient between the sealing material and the material to be sealed or the tightening bolt material.

FIG. 4 shows an embodiment of the present invention, in which the inside of a rubber O-ring seal 401 (on the high-temperature corrosive gas side ) is a low clamping force composite metal seal 400 in which a low clamping force metal seal 402 made of a metal having high temperature corrosion resistance, for example, approximately pure Ni is arranged. Although the reliability of the sealing performance between the surface of the low tightening force metal seal 402 made of approximately pure Ni and the surface of the sealed member 403 is low, the rubber O-ring seal 401 side from the low tightening force metal seal 402 is Since the amount of high temperature corrosive gas leaking to the rubber O-ring seal 401 is negligible compared to the amount of high temperature corrosive gas that comes into contact with the surface of the low tightening force metal seal 402, the reliability of the sealing performance of the rubber O-ring seal 401 is not affected. In addition, the elastic force of the entire low tightening force metal seal is set to be almost equal to the elastic force of the rubber O-ring seal 401 due to the shape of the part 401a of the rubber O-ring seal 401 included in the low tightening force metal seal 402. do. Specifically, the area of the contact portion 401b between the low tightening force metal seal 402 and a portion 401a of the rubber O-ring seal is shaped to be optimized.

FIG. 5 shows an embodiment of the present invention, in which the inside of a rubber O-ring seal 501 (on the high-temperature corrosive gas side ) is a composite metal seal 500 in which a low tightening force metal seal 502 made of a metal having high temperature corrosion resistance, for example, approximately pure Ni is arranged. Although the reliability of the sealing performance between the surface of the low tightening force metal seal 502 made of approximately pure Ni and the surface of the member to be sealed 503 is low, the rubber O-ring seal 501 side from the low tightening force metal seal 502 is Since the amount of high-temperature corrosive gas leaking to the rubber O-ring seal 501 is negligible compared to the amount of high-temperature corrosive gas that comes into contact with the surface of the low tightening force metal seal 502, the reliability of the sealing performance of the rubber O-ring seal 501 is not affected. In addition, the elastic force of the entire low tightening force metal seal is set to be almost equal to the elastic force of the rubber O-ring seal 501 due to the shape of the part 501a of the rubber O-ring seal 501 included in the low tightening force metal seal 502. do. Specifically, the area of the contact portion 501b between the low tightening force metal seal 502 and a portion 501a of the rubber O-ring seal is shaped to be optimized.

FIG. 6 shows an embodiment of the present invention, in which the inside of a rubber O-ring seal 601 (on the high-temperature corrosive gas side ) is a composite metal seal 600 in which a low tightening force metal seal 602 made of a metal having high temperature corrosion resistance, for example, approximately pure Ni is arranged. Although the reliability of the sealing performance between the surface of the low tightening force metal seal 602 made of approximately pure Ni and the surface of the sealed member 603 is low, the rubber O-ring seal 601 side from the low tightening force metal seal 602 is Since the amount of high-temperature corrosive gas leaking to the rubber O-ring seal 601 is negligible compared to the amount of high-temperature corrosive gas that comes into contact with the surface of the low tightening force metal seal 602, the reliability of the sealing performance of the rubber O-ring seal 601 is not affected. In addition, the elastic force of the entire low tightening force metal seal is set to be almost equal to the elastic force of the rubber O-ring seal 601 due to the shape of the part 601a of the rubber O-ring seal 601 included in the low tightening force metal seal 602. do. Specifically, the area of the contact portion 601b between the low tightening force metal seal 602 and a portion 601a of the rubber O-ring seal is shaped to be optimized.

FIG. 7 shows an embodiment of the present invention, in which the inside of a rubber O-ring seal 701 (on the high temperature corrosive gas side ) is a composite metal seal 700 in which a low tightening force metal seal 702 made of a metal having high temperature corrosion resistance, for example, approximately pure Ni is arranged. Although the reliability of the sealing performance between the surface of the low tightening force metal seal 702 made of approximately pure Ni and the surface of the sealed member 703 is low, the rubber O-ring seal 701 side from the low tightening force metal seal 702 is Since the amount of high-temperature corrosive gas leaking to the rubber O-ring seal 701 is negligible compared to the amount of high-temperature corrosive gas that comes into contact with the surface of the low tightening force metal seal 702, the reliability of the sealing performance of the rubber O-ring seal 701 is not affected. In addition, the elastic force of the entire low tightening force metal seal is set to be almost equal to the elastic force of the rubber O-ring seal 701 due to the shape of the part 701a of the rubber O-ring seal 701 included in the low tightening force metal seal 702. do. Specifically, the area of the contact portion 701b between the low tightening force metal seal 702 and a portion 701a of the rubber O-ring seal is shaped to be optimized. Here, the low tightening force metal seal 702 is obtained by cutting a metal sheet with a thickness equivalent to the radial width 704 into a rectangular shape, and having a recessed portion on the surface thereof containing a portion 701a of the rubber O-ring seal. It is shown in Japanese Patent Application No. 2020-100469 that even a low tightening force metal seal 702 cut by cutting can provide the same performance as a ring-shaped low tightening force metal seal 702.

The low-tightening-force composite metal seal, which consists of a low-tightening-force metal seal and a rubber O-ring seal, is shaped to fit into a conventional O-ring seal groove, so there is no need to change the design of the conventional seal structure. It can be used as a seal to upgrade the high-temperature corrosive gas resistance of existing equipment, so it can be used for new or used film deposition equipment or etching equipment where corrosive process gases and cleaning gases have higher flow rates and higher temperatures than before. It is useful as a seal.

It is also useful as a seal for exhaust pumps for film forming apparatuses and etching apparatuses that require high-temperature, large-flow process gases and cleaning gases, and piping sections of gas abatement apparatuses.

In addition, by placing a metal seal inside the conventional rubber O-ring seal, the amount of gas released from the rubber O-ring seal into the chamber is reduced, so high molecular weight gas from the rubber O-ring seal is It can also be used as a seal for semiconductor manufacturing equipment and analysis equipment where gas intrusion is discouraged.

100, 200, 300 Existing low tightening force metal seals 400, 500, 600, 700 Low tightening force composite metal seals 401, 501, 601, 701 Rubber O-ring seals 401a, 501a, 601a, 701a Rubber O-ring seals 401b, 501b, 601b, 701b Low clamping force metal seal and rubber O-ring Contact part with part of the seal 402, 502, 602, 702 Low clamping force metal seal 403, 503, 603, 703 Seal portion 704 Radial width of low tightening force metal seal

Claims (10)

A low tightening force composite metal seal that integrates a rubber O-ring seal on the outer periphery of a metal seal that can be inserted into the O-ring seal groove. A low clamping force composite metal seal in which the rubber O-ring seal according to claim 1 is made of a perfluoroelastomer specialized for high temperature resistance or a perfluoroelastomer containing an elastic reinforcing material. A low tightening force composite metal seal, wherein the metal seal according to claim 1 is made of substantially pure Ni. The low clamping force composite metal seal according to claim 1, claim 2, or claim 3 has a low clamping force in which a part of the rubber O-ring seal is included in the metal seal, and the shape of the rubber O-ring seal determines the elastic force of the metal seal. composite metal seal A low tightening force composite metal seal in which the elastic force of the entire metal seal is optimized by the proportion of the area where a part of the surface of the rubber O-ring seal contacts the metal seal according to claim 4. A film forming apparatus using the low tightening force composite metal seal according to claim 1, claim 2, claim 3, claim 4, or claim 5. An etching apparatus using the low clamping force composite metal seal according to claim 1, claim 2, claim 3, claim 4, or claim 5. An analysis device using the low tightening force composite metal seal according to claim 1, claim 2, claim 3, claim 4, or claim 5. Exhaust gas abatement device using the low tightening force composite metal seal according to claim 1, claim 2, claim 3, claim 4, or claim 5. A gas exhaust pump using the low tightening force composite metal seal according to claim 1, claim 2, claim 3, claim 4, or claim 5.