JP2021173410A - Backup ring seal with combination shape on composite seal of integrating rubber 0-ring seal with back-up ring seal - Google Patents

Abstract

To provide a backup ring seal shape that can efficiently manufacture a backup ring seal that improves seal performance of a rubber O-ring seal.SOLUTION: A backup ring seal 100c with a shape of storing a rubber 0-ring seal 200c in a groove is split into a circular arc part with a short curvature and long linear parts 110c, 120c and has a cut line which is cut from an outer peripheral side of a long shape in order to correspond to a circular arc part with a specific curvature to thereby become bendable, whereby the backup ring seal can correspond to any shapes.SELECTED DRAWING: Figure 3

Description

The present invention relates to a backup ring seal having a combined shape in a composite seal integrated with a backup ring seal that improves the sealing performance without impairing the handleability of the rubber 0-ring seal.

Compared to metal seals, in semiconductor manufacturing equipment or equipment that uses vacuum such as mass analyzers, it is easier to handle, the price is lower, it is easier to fit with the mating surface, and the mating seal. Rubber 0-ring seals are often used because they are resistant to displacement of the sealing surface due to the difference in thermal expansion rate from the surface. In order to further improve the accuracy, oxygen gas and water component gas in the atmosphere that diffuse and permeate the inside of the rubber 0-ring seal have become an obstacle to maintain the environment in the vacuum chamber within the specifications. That is, in order to achieve the specifications, the design of the rubber 0-ring seal should be changed to a metal seal, or the amount of process gas introduced into the vacuum chamber and the exhaust speed of the vacuum pump that exhausts the gas should be increased. Is becoming necessary. In addition, although it is not a vacuum device, even in an excimer laser that emits laser light by dissociating and combining certain gas molecules in the chamber, how to suppress oxygen gas and water component gas that enter the chamber is an issue. ..

In order to solve such a problem, in Japanese Patent Application No. 2019-144834, a backup ring seal having a shape that fits in the rubber 0-ring seal groove is arranged on the outer peripheral side or the inner peripheral side of the rubber 0-ring seal, and the chamber member. The sealing performance between the surface and the surface of the seal is achieved as before with the rubber 0-ring seal, and the reduction in the amount of gas that diffuses and permeates the inside of the rubber 0-ring seal is better than when the backup ring seal is made of rubber 0-ring seal. The material should have a sufficiently low gas permeability, and the sealing performance between the surface and the surface of the chamber member should be such that the rubber 0-ring seal has a surface condition of at least 10 to 30%, and the rubber 0-ring. It is proposed that the surface to be the sealing surface with the seal is in a surface state that can be sufficiently sealed, so that both seals are in close contact with each other to form a composite seal, and the sealing performance is improved as a whole. Further, Japanese Patent Application No. 2019-239715 proposes a shape of a backup ring seal that can be manufactured at low cost.

Literature

Patent Document 1

Japanese Patent Application No. 2019-144034

Patent Document 2

Japanese Patent Application No. 2019-239715

Patent Document 1 describes the key points of the backup ring seal for reducing the gas permeability of the rubber 0-ring seal and illustrates an example of the backup ring seal satisfying the requirements. Not mentioned. For trial production for performance confirmation, a backup ring seal with a circular rubber 0-ring seal can be easily processed with an NC lathe, etc., but a backup ring seal for a rubber 0-ring seal with a large diameter and non-circular shape Processing is not easy, and there is a demand for a shape of a backup ring seal that can be manufactured efficiently (at low cost). Further, Patent Document 2 of the application proposes a shape that can inexpensively manufacture a long backup ring seal that can be formed from a sheet material, but cannot cope with an arc shape having a short curvature.

In order to solve the above problems, a backup ring seal as shown in FIG. 1 of the present patent, that is, a backup ring seal having a shape that fits in the groove, is provided on the outer peripheral side of the rubber 0-ring seal 200 in order to solve the above problems. Alternatively, it is arranged on the inner peripheral side, and the sealing performance between the surface 300 of the vacuum chamber member and the surface of the seal is realized by the rubber 0-ring seal as before, and the reduction of the amount of gas diffused and permeated inside the rubber 0-ring seal is backed up. The ring seal is made of a material whose gas permeability is sufficiently lower than that of the rubber 0-ring seal, and the sealing performance between the surface and the surface of the vacuum chamber member is about 10 to 30% at the worst of the rubber 0-ring seal. By making the surface state, and further, by making the surface that becomes the sealing surface with the rubber 0-ring seal sufficiently sealable, the sealing performance is improved as a whole as a composite seal in which both seals are in close contact with each other. Ideally, the backup ring seal for this purpose should have a curved surface shape on the contact surface with the rubber 0-ring seal, and the stress distribution on the contact surface should be uniform. As shown above, if priority is given to facilitation of processing by compromising to some extent, it is better to make the contact surface shape straight (curvature R∞) as shown in 100b of FIG. 2 of the present patent, and further, for mass production. Is cut from a wide tape-shaped long material having a thickness w corresponding to the thickness w in FIG. 2 to a long shape having a width + α width corresponding to the height h in FIG. It is preferable to process the surface 400 at both ends of FIG. 2 in contact with the surface of the container to be sealed and the surface 500 in contact with the rubber 0-ring seal 200b of FIG. 2 to a predetermined size and surface finish. However, if the outer or inner circumference of the rubber 0-ring seal is not ring-shaped, for example, if the shape is made up of a combination of a long straight line and an arc with a short curvature, a long backup ring seal with a continuous entire circumference can be used. It becomes difficult to bend to correspond to the arc portion with a short curvature. Therefore, the arc part with a short curvature and the long straight part (including the arc part with a long curvature) are divided, and the backup ring seal member having a long shape and the backup ring seal member having an arc shape with a short curvature are combined. A ring seal is conceivable. Further, it is also effective to make a cut from the outer peripheral side of the long shape to make it bendable in order to correspond to the arc portion having a certain curvature, in order to reduce the number of members to be combined. From one experiment, it has been confirmed that a backup ring seal having such a combined shape has almost the same performance as a single backup seal if the gap between the combined portions is negligible.

The backup ring seal has a shape that fits in the conventional rubber 0-ring seal groove, and the combined shape of the backup seal has a ring shape regardless of the outer diameter or inner diameter of the 0-ring seal. Since it can be applied to such a shape, it can be applied without changing the design of the conventional seal part structure, and can be used as a backup ring seal for an upgrade composite seal of a used vacuum chamber, for example.

By storing the backup ring seal on the outside of the conventional rubber 0-ring seal, the part in contact with the gas in the vacuum chamber becomes the same rubber 0-ring seal as before, and the gas in the vacuum chamber and the seal surface The reaction and the influence of gas generated from the seal surface are the same as before, and it has the effect of significantly reducing the intrusion of oxygen gas and water component gas in the atmosphere into the vacuum chamber, and the oxygen gas in the chamber. It can be used as a backup ring seal for a vacuum device, for example, a composite seal for a film forming device, which dislikes an increase in concentration or water component gas concentration.

Although it is not a vacuum chamber, it can be used as a backup ring seal for a composite seal for a pressure chamber of an excimer laser device that dislikes the intrusion of oxygen gas or water component gas in the atmosphere into the chamber.

In addition, by housing the backup ring seal inside the conventional rubber 0-ring seal, the gas release rate generated from the rubber 0-ring seal is also reduced, so ultra-high-precision mass analysis that dislikes the intrusion of high-molecular-weight gas is disliked. It can be used as a backup ring seal for the composite seal for the vacuum pump of the device.

Backup ring seal of Japanese Patent Application No. 2019-144034 Backup ring seal of Japanese Patent Application No. 2019-239715 A backup ring seal having a combined shape according to the first embodiment of the present invention. A backup ring seal having a combined shape according to a second embodiment of the present invention.

FIG. 1 shows a composite seal in which the backup ring seal of Japanese Patent Application No. 2019-144034 is inserted. In this figure, the operation mechanism of the composite seal which is the basis of the present invention will be described. The solid line → path E is a gas path passing between the surface of the backup ring seal 100 arranged on the outside + the surface of the rubber 0-ring seal 200 and the flange surface 300. Here, even if the sealing effect on the surface of the backup ring seal 100 is inferior to that of the rubber 0-ring seal 200, the rubber O-ring seal 200 seals the path E, and as a result, the sealing performance on the flange surface 300 is achieved. Does not decrease. On the other hand, it is important to reduce the gas permeation amount of the broken line → path F and the alternate long and short dash line → path G in FIG. Here, since the path G passes through the backup ring seal 100 having a gas diffusion coefficient of 1/100 or less of the rubber 0-ring seal 200 before the gas invades the surface of the rubber 0-ring seal 200, the permeation path thereof. Even if the length is up to 1/10 of the rubber 0-ring seal 200, the number of gas invading the surface of the rubber 0-ring seal 200 on the atmospheric side is 1/10 or less of the conventional case where it was exposed to atmospheric pressure. become. Further, the path F is between the surface of the backup ring seal 100 and the flange surface 300 even if the sealing performance of the surface of the backup ring seal 100 is about 10 to 30% of the sealing performance of the surface of the rubber 0-ring seal 200. Only the gas that has passed reaches the atmospheric side surface of the rubber 0-ring seal 200, and most of the atmospheric side surface is in close contact with the surface of the backup ring seal 100. Therefore, the atmosphere of the rubber 0-ring seal 200 The number of gases entering the side surface is much less than 1/10 compared to the conventional case where it was exposed to atmospheric pressure. Therefore, this composite seal has a gas permeability of 1/10 or less when it is sealed only with the rubber 0-ring seal 200.

The degree of influence on the performance of the gap of the combined portion of the backup seal having the combined shape will be described with reference to FIG. 2 similar to the figure in Japanese Patent Application No. 2019-239715. The shape of the paired rubber 0-ring seal 200b does not have to be a circle, and basically any shape can be used, but for the sake of simplicity, the circular 0-ring seal 200b will be described here. .. In order to manufacture the backup ring seal 100b from a sheet-like raw material having a constant thickness, the contact surface with the rubber 0-ring seal 200b is formed into a straight line (R∞) shape. Even in this way, if the rubber 0-ring seal 200b is sufficiently compressed and used, the space surrounded by the flange surface 300b, the backup ring seal 100b, and the rubber 0-ring seal 200b becomes a negligible minute volume. Therefore, the performance of the backup ring seal 100b is almost the same as that of the backup ring seal 100 of FIG. Moreover, a tape-shaped backup ring seal 100b having a thickness w, a width h, and a length l (where l corresponds to the circumference of the contact surface with the rubber 0-ring seal) is provided with a gap Δt between both ends thereof. When the rubber 0-ring seal 200b is inserted into the outer circumference of the rubber 0-ring seal 200b with a minimum value, the effect on the gas permeability performance is only about Δt / l, which is a negligible amount. That is, even if the total of the gaps of the n combination portions is nΔt, the influence on the gas transmittance performance is only about nΔt / l, which is a negligible amount.

In the first embodiment of FIG. 3, when the shape of the rubber 0-ring seal is not a circle, for example, when it is a horizontally long rectangular shape and its corner is an arc with a short curvature, a circle having a radius corresponding to the curvature. A backup ring seal 100c having a shape obtained by combining a combination member 130c obtained by cutting a shape member and a long straight member 110c and 120c is attached to the outer circumference of the rubber 0-ring seal 200c, and the gas permeability of the rubber 0-ring seal Is being reduced.

In the second embodiment of FIG. 4, unlike the first embodiment, the arc-shaped member 130c is not individually prepared for the arc portion having a short curvature, and is indicated by 600 on the long straight member 140d. A cut is made from the outer peripheral side so that the portion bends in an arc, and a backup ring seal 100d having a combined shape with as few combination members as possible is attached to the outer circumference of the rubber 0-ring seal 200d, and the rubber 0 -The gas permeability of the ring seal is reduced.

When performing upgrade maintenance for the purpose of improving the performance of used film deposition equipment, a vacuum with a large exhaust speed is used by using the combination-shaped backup ring seal and rubber 0-ring seal shown in FIGS. 3 and 4. It is possible to reduce the concentration of atmospheric component gas such as oxygen gas and water component gas that enter the vacuum chamber in a small amount without changing to a pump. Further, it is possible to improve the sealing performance of the rubber 0-ring seal between the ceramic electrode and the aluminum member, for example, in a place where the metal seal cannot be used even if it is desired to be used, to almost the same level as the metal seal.

By using the combination-shaped backup ring seal and rubber 0-ring seal shown in FIGS. 3 and 4, the seal portion of the pressure chamber of the excima laser device designed with the rubber 0-ring seal specification can be inserted into the chamber. Since the gas intrusion rate of invading oxygen gas, water component gas, etc. can be reduced, it is possible to realize an excimer laser device in which the frequency of gas exchange in the chamber is reduced.

By using the combination-shaped backup ring seal shown in FIGS. 3 and 4 inside the rubber 0-ring seal, the amount of high-molecular-weight gas released from the rubber 0-ring of the vacuum pump entering the vacuum chamber can be reduced. It can be reduced, for example, making it easier to maintain the accuracy of the ultra-precision mass analyzer.

Further, by using the combination-shaped backup ring seal and rubber 0-ring seal shown in FIGS. 3 and 4, a sealing chamber that dislikes the intrusion of atmospheric components such as oxygen gas and water component gas, for example, an isolation transformer In the lens mounting portion of the endoscope, effects such as reduction of gas exchange frequency in the isolation transformer and prevention of semi-permanent fogging of the endoscope lens can be expected.

100, 100b, 100c, 100d backup ring seal
110c long lumber
120c Short long lumber
130c Member on arc
140d Long members with cuts on the outer circumference 200, 200b, 200c, 200d Rubber O-ring seals 300, 300b Flange surface 400 Backup ring seal Both ends 500 Backup ring seal rubber 0-contact surface with ring seal 600 Long member Cut made from the outer circumference of

Claims (7)

A backup ring seal with a constant width and thickness that can be adhered to a rubber O-ring seal, or a combination of several long materials. The backup ring seal according to claim 1, which is a combination of a long material having a cut in the outer peripheral portion of a long material having a constant width and a constant thickness and having an arc-shaped portion having a certain curvature. A film forming apparatus using a composite seal in which a backup ring seal having a combined shape of claim 1 or 2 and a rubber O-ring seal are combined. An excimer laser apparatus using a composite seal in which a backup ring seal having a shape according to claim 1 or a combination of claims 2 and a rubber O-ring seal are combined. A vacuum pump for a mass spectrometer using a composite seal in which a backup ring seal having a shape obtained by claim 1 or a combination of claims 2 is closely attached to the inner circumference of a rubber O-ring seal. A vacuum chamber using a composite seal in which a backup ring seal having a combined shape of claim 1 or 2 and a rubber O-ring seal are combined. A sealing chamber using a composite seal in which a backup ring seal having a combined shape of claim 1 or 2 and a rubber O-ring seal are combined.

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