KR101908094B1 - Magnetic fluid seal - Google Patents

Abstract

The present invention creates a nitrogen curtain to minimize the transfer of high heat or process gases in the process chamber to the magnetic fluid through the shaft and to separate the shaft in two stages to produce a portion of the shaft in direct contact with the process chamber, To propose a magnetic fluid seal that protects the product from byproducts caused by shaft corrosion. The magnetic fluid seal includes a housing, a shaft, a magnetic fluid, a V-piece and an A-piece, a permanent magnet, a first O-ring, a second O-ring, a third O-ring, a fourth O-ring, a spacer, a bearing, .

Description

Magnetic fluid seal < RTI ID = 0.0 >

The present invention relates to a magnetic fluid seal, and more particularly, to a method of manufacturing a magnetic fluid seal, in which nitrogen curtains are generated to minimize the transfer of high heat or process gas through the shaft to the magnetic fluid, And more particularly, to a magnetic fluid seal that separates a portion of a shaft that is in direct contact with a portion that does not, thereby protecting the product from by-products due to shaft corrosion.

When a unit process is performed in a vacuum chamber or a pressure chamber (hereinafter referred to as a " process chamber ") due to product production conditions or to improve the quality of a product, the process gas is injected into the high temperature chamber. A high-temperature vacuum chamber is also used for forming a thin film on a silicon wafer, removing a part of the thin film, or removing impurities from the substrate. Since the vacuum chamber must be maintained in a vacuum state, it is necessary to seal between the process chamber and the shaft. In the process chamber, a rotating shaft connected to the outside of the process chamber is used to transfer the driving force to the rotating chuck while supporting the wafer .

Various methods for sealing between the process chamber and the shaft have been proposed and used. In recent years, a magnetic fluid seal method has been widely used. A magnetic fluid is a compound of Ferro, which means to contain iron, and a fluid, which is a fluid. It is a fluid in which a magnetic powder is dispersed in a colloid state in a liquid and then a surfactant is added. The magnetic fluid seal maintains a plurality of magnetic fluids in the form of a ring between the shaft and the housing using the magnetic force of the permanent magnet, thereby preventing vacuum leakage and reaction gas leakage.

The magnetic fluid seals accelerate fluid deterioration when the high heat entering the vacuum chamber through the shaft and the process gas flow into the fluid ring side, shortening the life of the magnetic fluid seal. In addition, due to the process gas, the shaft is corroded, which affects the quality of the produced product due to the byproducts thereof.

Patent No. 10-1608595 (March 28, 2016)

It is an object of the present invention to create a nitrogen curtain to minimize the transfer of high heat or process gas in the process chamber to the magnetic fluid through the shaft and to separate the shaft into two stages, And to protect the product from by-products due to corrosion of the shaft.

According to an aspect of the present invention, there is provided a magnetic fluid seal comprising a housing, a shaft, a magnetic fluid, a V-piece and an A-piece, a permanent magnet, a first O-ring, a second O-ring, A spacer, a bearing, a nut, and a first stopper.

The housing has a cylindrical body and a flange formed at one end of the body and having a plurality of housing fastening holes and a first O-ring insertion groove formed therein. Wherein the shaft includes a shaft head and a shaft body formed of different materials, the shaft head and the shaft body are coupled to each other to form a gas trap therein, and one end of the shaft body is provided with a plurality of conduction- And a jaw is formed between the center and the opposite end of the shaft body. The magnetic fluid is positioned between the second stopper formed at the center of the shaft body and the conduction-reduction hole while surrounding the shaft body. The V-pole piece and the A-pole piece are installed in a line in the direction of the conduction-damping hole from the second stopper at the outer periphery of the magnetic fluid. The permanent magnet is positioned between the V-pole piece and the A-pole piece. The first O-ring is located at the O-ring fixing jaw formed at one end of the V-pole piece. The second O-ring and the third O-ring are inserted into a second O-ring insertion groove formed in the V-pole piece and a third oil insertion groove formed in the A-pole piece, respectively. The fourth O-ring is located in the first O-ring insertion groove of the flange. The spacer is positioned between the bearing and the A-piece. The bearing is installed between the second stopper and a jaw formed with a threaded groove of the shaft body. The nut is fastened to the jaw of the shaft body. The first stopper is fastened to the lower portion of the housing.

The magnetic fluid seal according to the present invention creates a nitrogen curtain to minimize the transfer of high heat or process gases in the process chamber to the magnetic fluid through the shaft, to separate the shaft into two stages, It is possible to protect the product from byproducts caused by corrosion of the shaft.

1 shows a magnetic fluid seal according to the present invention.
2 shows a state in which a magnetic fluid seal according to the present invention is assembled.
Figure 3 shows a magnetic fluid seal according to the present invention mounted in a process chamber.

In order to fully understand the present invention and the operational advantages of the present invention and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings, which are provided for explaining exemplary embodiments of the present invention, and the contents of the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

1 shows a magnetic fluid seal according to the present invention.

FIG. 1A is an exploded perspective view of a magnetic fluid seal according to the present invention, FIG. 1B is a perspective view of a magnetic fluid located on an outer ring of a coupled shaft, and FIG. 1C is a perspective view of a magnetic fluid seal incorporating other components except a housing.

In FIG. 1A, a process chamber 200 is shown in addition to the magnetic fluid seal 100 according to the present invention for convenience of description.

1, a magnetic fluid seal 100 according to the present invention includes a housing 110, shafts 120 and 121, a magnetic fluid 129, two pole pieces 130 and 131 and 135, All of the permanent magnets 140, the four O-rings 150, 151, 152, 153 and 154, the gas pipe 160, the spacer 165, the bearing 170, the nut 175 and the first stopper 180 Or a combination of parts.

The housing 110 is coupled to the body 111 and the flange 112 and a nitrogen pipe connection hole 115 is formed on a side surface of the cylindrical body 111. A plurality of housing fastening holes 113 and ring insertion grooves 114 are formed in a donut-shaped flange 112 having an empty interior. A plurality of housing fastening holes 113 formed in the flange 112 and a bolt fastening thread 201 of the process chamber 200 are fastened to each other using a bolt (not shown) The seal 100 is fastened to the process chamber 200.

The shaft 120 (121, 125) comprises a shaft head 121 and a shaft body 125, each of which is of a separable shape, A plurality of bolts 190 are fastened to the second fastening threads 124 formed on the upper surface of the shaft body 125 through the first fastening holes 122 formed on the upper surface of the shaft head 121, , 125 are combined. A space commonly formed by the two shafts 121 and 125 is referred to as a gas trap (see FIG. 3, 300, described later). The gas trap will be described later. The shaft head 121 protrudes through the open portion of the upper portion of the housing 110 and protrudes out of the housing 110 so that a portion of the shaft head 121 is in contact with the open hole 202 of the process chamber 200 Lt; RTI ID = 0.0 > 200 < / RTI >

The shaft is generally made of a strong material, such as iron, because the shaft of such a material has a good thermal conductivity, so that the heat in the process chamber 200 can be transferred to the magnetic fluid described later through the shaft to shorten the service life of the magnetic fluid. It has already been explained that it is a cause. The present invention proposes that the shaft head 121 inserted into the process chamber 200 and the shaft body 125 distant from the process chamber 200 are formed of different materials and then used. For example, it is proposed that the material of the shaft head 121 is a nickel alloy, and the material of the shaft body 125 is made of a stainless steel alloy.

A gas trap 300 is formed inside the shaft head 121 and the shaft body 125 so that the high heat transferred from the process chamber 200 and the process gas can be diluted and maximally delayed from flowing into the magnetic fluid side The present invention proposes forming a plurality of conduction damping holes 126 in the shaft body 125 that can minimize the transmission of heat to the shaft body 125. [ The plurality of conduction damping holes 126 are formed at one end of the shaft body 125, that is, at a portion close to the portion in contact with the shaft head 121.

A second stopper 127 protruding outward is formed at the center of the shaft main body 125 and a second stopper 127 is formed between the opposite end of the step where the plurality of conduction attenuating holes 126 of the shaft main body 125 are formed A step 128 with a thread groove is formed. The diameter between the second stopper 127 and the jaw 128 is larger than the diameter between the jaw 128 and the opposite end. The magnetic fluid 129 to be protected from the heat of the process chamber is formed in a ring shape between the second stopper 127 and the plurality of conduction damping holes 126. [ The magnetic fluid 129 described in the following description is a concept that includes a magnetic fluid ring 129.

The two pole pieces 130, that is, the V-pole piece 131 and the A-pole piece 135 are connected in series to each other so as to form a constant gap between the inner ring of the two pole pieces 131 and 135 and the outer ring of the shaft body 125 A magnetic fluid 129 attracted by the magnetic force of the permanent magnet 140 is placed in this space. The V-pole piece 131 has a nitrogen inlet passage 132 formed at a side surface thereof, a second O-ring fixing groove 133 formed at a side end thereof, and an O-ring fixing jaw 134 formed at an opposite side end thereof. The A-piece 135 has a third O-ring fixing groove 136 formed at a side end thereof.

In the present invention, a nitrogen shielding film for blocking heat or gas transferred to the magnetic fluid through the shaft is further introduced. The nitrogen gas is introduced into the gas pipe 160, the nitrogen pipe connecting groove 115 and the nitrogen inlet passage 132, The nitrogen shielding film may be formed by moving through the shaft head 121 and the gas trap 300 formed in the shaft body 125 to the plurality of conduction reduction holes 126.

The permanent magnet 140 is installed between the V-pole piece 131 and the A-pole piece 135.

The first O-ring 151 of the four O-rings 150, 151, 152, 153 and 154 is located at the O-ring fixing jaw 134 of the V-pole piece 131, The third O-ring 153 is inserted into the second O-ring fixing groove 133 of the V-pole piece 131 and the third O-ring fixing groove 136 of the A-pole piece 135, And is located in the first O-ring insertion groove 114 formed in the flange 112.

The gas pipe 160 is connected to the nitrogen pipe connection groove 115 of the housing 110 to supply nitrogen gas to the gas trap 300 of the shaft 120. As will be described later, the nitrogen gas supplied through the gas pipe 160 is moved to the inside of the process chamber 200 through the conduction attenuation holes 126 and removed.

A spacer 165 is positioned between the lower end of the A pole piece 135 and the bearing 170.

The bearing 170 is installed between the second stopper 127 and the jaw 128 of the shaft body 125. The inner ring of the bearing 170 catches the shaft of the shaft body 125, Thereby fixing the housing 110.

The nut 175 is fastened to the stepped groove 128 formed in the shaft body 125 to fix the bearing 170.

The first stopper 180 functions to hold a part of the outer ring of the bearing 170 and fix it to the lower end of the housing 110. The first stopper 180 is formed with a second fastening hole 181. The first stopper 180 can be fastened to the lower end of the housing 110 using bolts 191. [

In the above description, the V pole piece 131, the A pole piece 135, the permanent magnet 140, the first O ring 151, the second O ring 152, the third O ring 153, the fourth O ring 154 The spacer 165, the bearing 170, the nut 175, the magnetic fluid 129, and the first stopper 180 all have a structure to enclose the body of the shaft body 125.

1C, each of the components constituting the magnetic fluid seal 100 according to the present invention includes a first stopper 180, a bearing 170, a space 165, an A pole piece 135, The O-ring 153, the permanent magnet 140, the second O-ring 152, the V-pole piece 131 and the first O-ring 151 are arranged in order from the middle of the shaft body 125 in the direction of the shaft head 121 Are combined. The magnetic fluid 129 is positioned between the inner ring of the V-piece 131 and the A-pole piece 135 and the outer ring of the shaft body 125, and the permanent magnet 140 is positioned between the magnetic fluids 129 The magnetic fluid 129 on both sides is being pulled.

2 shows a state in which a magnetic fluid seal according to the present invention is assembled.

FIG. 2A is a side view of the magnetic fluid seal according to the present invention, FIG. 2B is a perspective view of the magnetic fluid seal according to the present invention, and FIG. 2C is a perspective view of the magnetic fluid seal according to the present invention.

Referring to FIG. 2, the magnetic fluid seal 100 according to the present invention includes a housing 110, a flange 112 that protrudes outward from a flange 112 constituting the housing 110, The gas pipe 160 connected to the side surface of the housing 110, the lower portion of the shaft body 125 and the first stopper 180 are observable while the remaining components are the inside of the housing 110 As shown in FIG.

2, the shaft head 121 and the shaft body 125 are separately manufactured from different materials, and then joined together using a bolt or the like, which is one of the core ideas of the present invention.

A gas trap 300 is provided in an inner portion of the shafts 120, 121 and 125 which are coupled to each other. The gas trap 300 is provided at a position where the nitrogen gas flowing through the gas pipe 160 is filled, It is another key idea of the present invention that heat and process gases that may flow from the process chamber 200 by nitrogen gas may minimize adverse effects on the shaft and the magnetic fluid.

A plurality of conduction reduction holes 126 formed in a part of the shaft body 125 is also one of the key ideas of the present invention.

Figure 3 shows a magnetic fluid seal according to the present invention mounted in a process chamber.

FIG. 3A is a side view of the magnetic fluid seal according to the present invention mounted on the process chamber, FIG. 3B is a perspective view of the lower side of the magnetic fluid seal according to the present invention mounted on the process chamber, Sectional view of the magnetic fluid seal according to the present invention in a state in which the magnetic fluid seal is mounted in the process chamber, and FIG. 3D is a sectional view of the magnetic fluid seal according to the present invention in a state in which the magnetic fluid seal is mounted in the process chamber.

3D, the nitrogen gas fills the gas trap 300 of the shaft 120 through the gas pipe 160, and the conduction attenuation holes (not shown) 126 to form a nitrogen gas film to generate a nitrogen curtain effect, and then move to the inside of the process chamber 200.

3, a magnetic fluid seal 100 according to the present invention is mounted to a process chamber 200 through a flange 112 of a housing 110 and a portion of a shaft head 121 is coupled to a process chamber 200, As shown in FIG. Since the shaft head 121 is inserted into the process chamber 200, the high heat and process gas in the process chamber 200 are introduced into the magnetic fluid 129 via the shaft 120, It can be easily expected that the shaft 200 is corroded and the service life of the shaft 120 is shortened.

In consideration of this situation, in the present invention, nitrogen gas having a lower temperature than the room temperature or the process gas is supplied through the gas pipe 160 connected to the process facility nitrogen gas pipe (not shown). As described above, the nitrogen gas moves through the gas pipe 160, the nitrogen inlet passage 132, and the gas trap 300 to the conduction attenuation holes 126 to form a gas barrier film. The gas barrier layer, which is made of nitrogen gas at a lower temperature than the process gas, dilutes the process gas while lowering the temperature of the process gas when the high heat and process gas in the process chamber 200 are introduced into the magnetic fluid through the shaft, 129 can be prevented from being blocked.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

110: Housing
111: Body 112: Flange
113: housing fastening hole 114: first O-ring insertion groove
115: Nitrogen piping connection hole
120: shaft
121: shaft head 122: first fastening hole
124: second fastening thread 125: shaft body
126: conduction attenuation hole 127: second stopper
128: chin 129: magnetic fluid (ring)
130: Two pole pieces
131: V pole piece 132: Nitrogen inlet passage
133: second O-ring fixing groove 134: O-ring fixing jaw
135: A pole piece 136: Third O-ring fixing groove
140: permanent magnet
150: Four O rings
151: first o-ring 152: second o-ring
153: third o-ring 154: fourth o-ring
160: Gas piping
165: Spacer
170: Bearings
175: Nuts
180: first stopper
181: second fastening hole
200: process chamber
201: bolt fastening thread 202: open hole
300: gas trap

Claims (6)

A housing having a cylindrical body and a flange formed at one end of the body and having a plurality of housing fastening holes and a first O-ring insertion groove formed therein;
The shaft head and the shaft main body are coupled to each other to form a gas trap therein. A plurality of conduction damping holes are formed at one end of the shaft main body A shaft having a jaw formed between a center and an opposite end of the shaft body;
A magnetic fluid surrounding the shaft body between a second stopper formed at the center of the shaft body and the conduction-damping hole;
A V pole piece and an A pole piece provided in a line in the direction of the conduction damping hole from the second stopper at an outer periphery of the magnetic fluid;
A permanent magnet positioned between the V pole piece and the A pole piece;
A first O-ring located at an O-ring fixing jaw formed at one end of the V-pole piece;
A second O-ring insertion groove formed in the V-piece and a second O-ring and a third O-ring inserted in the third oil insertion groove formed in the A-piece, respectively;
A fourth O-ring located in the first O-ring insertion groove of the flange;
A bearing installed between the second stopper and a jaw having a screw groove formed in the shaft body;
A spacer positioned between said A-piece and said bearing;
A nut fastened to the jaw of the shaft body; And
A first stopper fastened to a lower portion of the housing;
And a magnetic fluid seal. The method according to claim 1,
A nitrogen piping connection hole formed on an outer surface of the housing;
A first fastening hole formed in the shaft head; And
A gas pipe for supplying and exhausting nitrogen gas to the gas trap through the nitrogen pipe connection hole and the first connection hole; of
Wherein the magnetic fluid seal further comprises: The method according to claim 1,
A magnetic fluid ring formed between the conduction damping hole and the second stopper in a space formed by the V pole piece connected to each other, the inner ring of the A pole piece, and the outer ring of the shaft body; of
Wherein the magnetic fluid seal further comprises: The method according to claim 1,
Wherein the shaft head and the shaft main body are made of a material having a high-
Each of which is a nickel alloy and a stainless steel alloy. The method according to claim 1,
Wherein the magnetic flux, the V pole piece, the A pole piece, the permanent magnet, the first O ring, the second O ring, the third O ring, the fourth O ring, the spacer, the bearing, the nut, The stopper is engaged with the shaft of the shaft while being wrapped around the shaft,
Wherein the shaft, the V-pole piece, the A-pole piece, the permanent magnet, the first O-ring, the second O-ring, the third O-ring, the fourth O-ring, the spacer, The first stopper being located inside the housing,
Wherein a portion of the shaft head is exposed on one side of the housing and a portion of the shaft body is exposed on an opposite side of the housing. 6. The magnetic fluid seal of claim 5,
Wherein said fastening means is fastened to said process chamber by fastening bolt fastening threads formed in said process chamber and said plurality of housing fastening holes of said flange.

Images