JPH08121337A - Cryopanel - Google Patents

Abstract

PURPOSE: To increase the performance of a pump with simple structure and provision of sufficient displacement. CONSTITUTION: A cryopanel which is provided on the inside of a pump case 1, installed on the heat station 2 of a refrigerator 3, and condensates and adsorbs gas is installed on the heat station 2. Also it comprises a mounting part 6 extending toward the outside of the heat station 2, a first panel part 7 projected axially to one side of the refrigerator 3 from around the periphery of the mounting part 6, and a second panel part 8 which is projected axially to the other side of the refrigerator 3 from around the periphery of the mounting part 6 and to the inner surface of which activated carbon 9 is attached. Then water and low boiling point gas are condensated in one panel part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cryopanel, and more particularly to a cryopanel of a cryopump used to make a load lock chamber, a processing chamber and the like a high vacuum.

[0002]

2. Description of the Related Art Conventionally, as a cryopump in which a cryopanel and a shield panel having a baffle are combined with one heat station, one disclosed in, for example, Japanese Patent Laid-Open No. 2-5773 is known.

As shown in FIG. 4, this cryopump has a cryogenic expander A in a pump case C whose one side is open.
The heat station H is installed inside, and the bottom wall of a cryopanel CP having an activated carbon CH adhered to the inner surface is connected to the heat station H as a bottomed cylinder, and the pump case C is connected to the cryopanel CP. The shield panel SP for preventing the radiant heat is made into a double cylinder shape, the inner cylinder part thereof is used as a mounting cylinder part, and the end part of this mounting cylinder part is connected to the heat station H. The low heat conduction part D is provided.

Further, a baffle B is arranged at the open portion of the pump case C, and the baffle B is supported by the shield panel SP.

And, by the shield panel SP,
Radiation heat from the pump case C to the cryopanel CP is blocked, the baffle B is cooled, and moisture is condensed and adsorbed on the surface of the baffle B.

Further, the low heat conduction part D makes it difficult for the heat of the shield panel SP to be transferred to the heat station H, and at the same time, makes the temperature of the shield panel SP higher than that of the heat station H, thereby making a temperature difference between them. The low boiling point gas such as oxygen, nitrogen, and argon gas is provided so as to be condensed only in the cryopanel CP directly connected to the heat station H.

[0007]

However, in the conventional cryopump, the shield panel SP is arranged around the cryopanel CP in order to block radiant heat from the pump case C to the cryopanel CP, Since the baffle B is provided in the open part of the pump case C, the exhaust speed of water can be considerably increased by the baffle B, but water having a low boiling point other than water is condensed and accumulated. Since it has to pass through the narrow gap of the baffle B, a large resistance is exerted when passing through, and there is a problem that the probability of gas reaching the cryopanel CP is reduced and the exhaust speed is reduced.

Further, between the shield panel SP and the pump case C, there is a wasteful space which is not used for exhausting the low boiling point gas, and the exhaust efficiency is lowered.

Moreover, since the shield panel SP is housed in the pump case C and the cryopanel CP is housed in the shield panel SP, the surface area of the cryopanel CP in the pump case C is small. Therefore, there is a problem that the condensation probability of low boiling point gas such as nitrogen or argon gas is reduced, and the exhaust by the cryopump cannot be performed efficiently.

An object of the present invention is to have a simple structure and
The point is to provide a cryopanel capable of obtaining a sufficient displacement and to improve pump performance.

[0011]

In order to achieve the above object, the invention according to claim 1 is a cryostat which is installed in a pump case 1 and is attached to a heat station 2 of a refrigerator 3 to condense and adsorb gas. A panel is attached to the heat station 2, an attaching portion 6 extending outward of the heat station 2, and a first panel portion 7 projecting to one side in the axial direction of the refrigerator 3 at an outer peripheral portion of the attaching portion 6. A second panel portion 8 that protrudes to the other side in the axial direction of the refrigerator 3 at the outer peripheral portion of the mounting portion 6 and has activated carbon 9 attached to the inner surface thereof.
It consisted of

According to the second aspect of the present invention, the first panel portion 7 and the second panel portion 8 are formed in a tubular shape.

According to a third aspect of the present invention, the first panel portion 7 and the second panel portion 8 are formed by a continuous tubular member 51, and the mounting portion 6 made of a plate member 52 is fixed in the tubular member 51. I did.

According to the fourth aspect of the present invention, the bottom portions 53a, 53a of the two bottomed tubular members 53, 53 are butted against each other, and the butted portion serves as the mounting portion 6, and the tubular portions 53b, 53b are respectively provided. The first panel portion 7 and the second panel portion 8 are formed.

According to a fifth aspect of the present invention, the first panel portion 7 and the second panel portion 8 are composed of a plurality of plate-shaped members 54, and these plate-shaped members 54 are provided on the outer peripheral portion of the mounting portion 6. ,
It is provided radially at predetermined intervals in the circumferential direction.

[0016]

According to the first aspect of the present invention, for example, the first panel portion 7 can be projected toward the gas introduction side of the pump case 1, so that water and nitrogen can be applied to the inner side of the first panel portion 7 without resistance. , A low boiling point gas such as argon can be introduced, and not only water but also nitrogen,
A low boiling point gas such as argon is condensed more efficiently than before, and the hydrogen gas that is adsorbed by the first panel portion 7 and is not adsorbed by the first panel portion 7 is transferred to the inner surface of the second panel portion 8. The hydrogen gas can be adsorbed by the activated carbon for adsorbing hydrogen on the.

Further, since no conventional shield panel is provided in the pump case 1, it is possible to eliminate a wasteful space which is not used for exhausting the low boiling point gas, which has been conventionally generated, and it is possible to further increase the exhaust speed. However, the first panel part 7 and the second panel part 8 of the cryopanel can be enlarged to the space where the shield panel is installed, without installing the shield panel,
The cryopanel can be made larger than the conventional one. Therefore, the area where the low boiling point gas such as oxygen, nitrogen, and argon in the first panel portion 7 is condensed and the activated carbon 9 attached to the inner surface of the second panel portion 8 are used for hydrogen. Since the adsorption area for adsorbing the gas can be increased, the exhaust speed as a whole can be further increased.

By eliminating the conventional shield panel, the cost can be reduced accordingly.
Since the structure is simple, assembly workability can be improved.

According to the second aspect of the present invention, since the first panel portion 7 and the second panel portion 8 are formed in a cylindrical shape, when the pump case 1 is formed in a cylindrical shape, each panel is formed along the inner surface thereof. Since the parts 7 and 8 can be formed, the surface area can be increased more efficiently while simplifying the structure.

According to the third aspect of the invention, the first panel portion 7 and the second panel portion 8 are formed by a continuous tubular member 51, and the mounting portion 6 made of a plate member 52 is fixed in the tubular member 51. Therefore, by arbitrarily setting the mounting position of the plate member 52 to the tubular member 51, each panel portion 7,
Since the axial length of 8 can be freely set to a desired length, the exhaust performance of water, argon, nitrogen, and other gases exhausted by the condensation action and the hydrogen exhausted by the adsorption action of the activated carbon 9 The balance with the exhaust performance of the gas can be variously set according to the purpose.

In the invention according to claim 4, the bottom portions 53a, 53a of the two bottomed tubular members 53, 53 are butted, and the butted portions are formed as the mounting portion 6, and the tubular portions 53b, 53b are respectively made. Since the first panel portion 7 and the second panel portion 8 are formed, the bottom portions 53a and 53 of the bottomed tubular members 53 and 53 are formed.
Since the cryopanel can be formed only by abutting and fixing a, the processing can be simplified, and the diameter and the tube length of the first panel portion 7 and the second panel portion 8 can be individually set. Multiple types of cryopanels can be formed by combining them.

According to the fifth aspect of the present invention, the first panel portion 7 and the second panel portion 8 are composed of a plurality of plate-shaped members 54, and these plate-shaped members 54 are provided on the outer peripheral portion of the mounting portion 6. ,
Since they are provided radially at predetermined intervals in the circumferential direction, the hydrogen gas that is not adsorbed from the inner portion of the first panel portion 7 in which the low boiling point gas is condensed by the gap formed between the plate-like members 54. Since it is possible to easily reach the inner portion of the second panel portion 8, it is possible to increase the exhaust rate of hydrogen gas.

Further, since each member forming the cryopump can be formed by a plate-shaped member, when a tubular member is formed, such a special mold is required as compared with the case where a special mold is required. Since it is not necessary and the plate members 54 can be easily fixed to the mounting portion 6, the processing can be further facilitated and the cost can be reduced.

[0024]

In the first embodiment shown in FIG. 1, a cylinder 4 of a gas expansion type refrigerator 3 having a heat station 2 and a helium gas as a working fluid is installed in a pump case 1 having an upper opening. Together with the heat station 2
And a tubular cryopanel 5 surrounding the cylinder 4.
Are connected by being brought into thermal contact with each other.

The cryopanel 5 of the first embodiment shown in FIG. 1 is mounted in thermal contact with the heat station 2 and has a disk-shaped mounting portion 6 extending outward in the radial direction of the heat station 2. And, in the outer peripheral portion of the mounting portion 6, one side in the axial direction of the refrigerator 3, that is, the pump case 1
To the opening of the first panel portion 7 protruding to near the opening and having activated carbon 9 for adsorbing hydrogen molecules attached to the inner surface thereof.
And a second panel portion 8 that protrudes toward the other side in the axial direction of the refrigerator 3 at the outer peripheral portion of the mounting portion 6 and near the bottom portion of the pump case 1, and the first panel portion 7 And the second panel portion 8 are formed in a cylindrical shape.

Further, the cryopanel 5 of the first embodiment.
Comprises a tubular member 51 and a disc-shaped plate member 52 fixed in the tubular member 51. By fixing the plate member 52 in the tubular member 51, the plate member 52 is Without the attachment portion 6, and with the attachment portion 6 as a boundary, the tubular member 5
The first panel portion 7 and the second panel portion 8 are continuously formed at 1.

A flange portion 52a extending toward one side in the axial direction is formed on the entire outer peripheral edge of the plate member 52, and the flange portion 52a is fixed to the cylindrical member 51.

Activated carbon 9 for adsorbing hydrogen molecules is attached to the inner peripheral surface of the second panel portion 8 of the tubular member 51.

Further, each of the panel portions 7 and 8 is cooled by the heat station 2 through the attachment portion 6 so that the axial tip end portion thereof maintains approximately 20 K or less (K is an absolute temperature). Has been done.

With the above structure, water and low boiling point gases such as oxygen, nitrogen, and argon are condensed in the first panel portion 7 and are attached to the inner peripheral surface of the second panel portion 8. Further, the activated carbon 9 is made to adsorb hydrogen gas and the gas is exhausted.

Table 1 shows a comparison between the pumping speed of the cryopump in the first embodiment and the pumping speed of the conventional cryopump having the structure shown in FIG.
As shown in

[0032]

[Table 1]

Therefore, in the first embodiment, the pumping speed of water is almost the same as the conventional one without the baffle.
The exhaust rate of the argon gas and the nitrogen gas is twice or more that of the conventional one.

As described above, in the first embodiment, the cryopanel 5 is attached to the heat station 2, the attachment portion 6 extending outward of the heat station 2 and the refrigerator at the outer peripheral portion of the attachment portion 6. 3 is composed of a first panel portion 7 projecting to one side in the axial direction and a second panel portion 8 projecting to the other side in the axial direction of the refrigerator 3 at the outer peripheral portion of the mounting portion 6, the pump case Since water and a low boiling point gas such as nitrogen or argon can be introduced from the processing chamber to the inner side of the first panel portion 7 projecting toward the opening of No. 1, water inside the first panel portion 7 can be introduced. Not only the low boiling point gas such as nitrogen and argon can be condensed and exhausted more efficiently as compared with the conventional one, the first panel portion 7
The hydrogen gas that has not been adsorbed on the second panel portion 8 can be adsorbed on the activated carbon 9 attached to the second panel portion 8.

Further, since no conventional shield panel is provided inside the pump case 1, it is possible to eliminate a conventional waste space which is not used for exhausting the low boiling point gas, and to increase the exhaust speed. Also, since the first panel portion 7 and the second panel portion 8 of the cryopanel 5 can be enlarged up to the space near the interior of the shield panel, the cryopanel can be made larger than the conventional one, and the adsorption area can be increased. Just increased, oxygen, nitrogen,
It is possible to further increase the exhaust rate of low boiling point gas such as argon and hydrogen gas.

Further, since the conventional shield panel can be eliminated, the cost can be reduced accordingly, and the structure is simple, so that the assembling workability can be improved. Further, in the first embodiment, since the first panel portion 7 and the second panel portion 8 are formed in a cylindrical shape, the respective panel portions 7, 8 are formed along the inner peripheral surface of the cylindrical pump case 1. Since it can be formed, the surface area can be increased more efficiently while simplifying the structure.

Moreover, since the first panel portion 7 and the second panel portion 8 are formed by the continuous tubular member 51, and the mounting portion 6 composed of the plate member 52 is fixed in the tubular member 51,
By arbitrarily setting the attachment position of the plate member 52 to the cylindrical member 51, the axial length of each panel portion 7, 8 can be freely set to a desired length, so that the condensation action can be achieved. It is possible to set various balances between the exhaust performance of gases such as water, argon, and nitrogen to be exhausted, and the exhaust performance of gases such as hydrogen to be exhausted by the adsorption action of the activated carbon 9, depending on the purpose.

Next, a second embodiment of the cryopanel will be described with reference to FIG. The cryopanel 5 of the second embodiment is
The bottomed tubular members 53, 53 having two cylinders are formed. The bottomed tubular members 53, 53 are abutted against each other at the bottom portions 53a, 53a, and the abutted portion is formed as the mounting portion 6. , The cylindrical portions 53b and 53b are respectively connected to the first panel portion 7
And the second panel portion 8.

In the second embodiment, each bottomed tubular member 5 is
3, 3 and 53 have the same diameter, and the lengths of the cylindrical portions 53b and 53b are changed. The short side of the tubular portion 53b is formed as the first panel portion 7, the long side of the tubular portion 53b is formed as the second panel portion 8, and the activated carbon 9 is attached to the inner surface of the second panel portion 8. I am letting you.

The bottomed tubular members 53, 53 may have the same diameter or may have different diameters, and the lengths of the tubular portions 53b, 53b may be set arbitrarily. it can.

As described above, the cryopanel 5 of the second embodiment is composed of the two bottomed tubular members 53, 53,
The bottom portions 53a, 53a of the bottomed tubular members 53, 53, respectively.
Butt, and this butted portion is formed as a mounting portion 6, and each tubular portion 5
Since 3b and 53b are composed of the first panel portion 7 and the second panel portion 8, respectively, the cryopanel 5 can be formed only by abutting and fixing the bottom portions 53a and 53a of the bottomed tubular members 53 and 53. Therefore, the processing can be made easier, and the diameters and the tube lengths of the first panel portion 7 and the second panel portion 8 can be individually set, so that various types of cryopanels 5 can be formed by combining them. Can be done.

Although the cryopumps of the first and second embodiments are formed in a cylindrical shape, they may be formed in a polygonal cylindrical shape.

Next, the cryopanel of the third embodiment will be described with reference to FIG. The cryopanel 5 of the third embodiment is
The first panel portion 7 and the second panel portion 8 are composed of a plurality of plate-shaped members 54, and these plate-shaped members 54 are radially provided on the outer peripheral portion of the mounting portion 6 at predetermined intervals in the circumferential direction. It is a thing.

The plate member 55 constituting the mounting portion 6 has a regular hexagonal shape, and the flange portions 55a, 55 extending toward one side in the axial direction at every other side out of the six sides of the outer peripheral portion.
a and 55a are formed.

Further, the plate members 54 are fixed to the respective flange portions 55a of the mounting portion 6, and these plate members 54 are connected to the first panel portion 7 by one plate member 54. The second panel portion 8 is formed continuously, and its cross-sectional shape is a U-shape that spreads toward the end along the outer periphery of the regular hexagon of the mounting portion 6.

Then, each plate member 54 is fixed to the mounting portion 6 so as to form a predetermined gap between the adjacent circumferential end portions, and the mounting portion 6 serves as a boundary. The first panel portion 7 is projected on one side in the axial direction, and the second panel portion 8 is projected on the other side in the axial direction.

Although the mounting portion 6 is formed in a regular hexagonal shape, it is not limited to a hexagonal shape and may be formed in various polygonal shapes as long as a predetermined gap can be formed between the plate-shaped members 54. it can.

Further, in the third embodiment, one plate member 5 is used.
Although the first panel portion 7 and the second panel portion 8 are continuously formed by means of No. 4, they may be formed by separate plate members 54, respectively. For example, the first panel portion 7 and the second panel portion 8 are attached so as to open a gap alternately in the axial direction.

As described above, in the cryopanel 5 of the third embodiment, the first panel portion 7 and the second panel portion 8 are composed of a plurality of plate-shaped members 54, and these plate-shaped members 54 are attached. Since the outer peripheral portion of the portion 6 is provided radially at predetermined intervals in the circumferential direction, the inner portion of the first panel portion 7 in which the low boiling point gas is condensed by the gap formed between the plate-shaped members 54. Since the hydrogen gas that has not been adsorbed can easily reach the inner portion of the other second panel portion 8, the adsorption of hydrogen gas on the activated carbon 9 for adsorbing hydrogen that is attached to the inner surface of the second panel portion 8 Since it can be performed satisfactorily, the exhaust rate of hydrogen gas can be increased.

Further, since each member constituting the cryopanel 5 can be formed by a plate-shaped member, a special mold is required when forming a tubular member as in the first and second embodiments. In comparison with the above, no special mold is required, and the plate members 54 can be easily fixed to the mounting portion 6, so that the processing can be facilitated and the cost can be reduced. .

[0051]

According to the first aspect of the present invention, for example, the first panel portion 7 can be projected toward the gas introduction side of the pump case 1, so that the resistance to the inner side of the first panel portion 7 can be obtained. It is possible to introduce water and a low-boiling point gas such as nitrogen or argon, and efficiently condense not only water but also a low-boiling point gas such as nitrogen or argon inside the first panel portion 7 as compared with the conventional case. You can do it.

Further, when a conventional shield panel is not provided inside the pump case 1, it is possible to eliminate a wasteful space which is not used for exhausting the low boiling point gas, which has been conventionally generated, and it is possible to further increase the exhaust speed. However, the first panel part 7 and the second panel part 8 of the cryopanel can be enlarged to the space where the shield panel is installed, without installing the shield panel,
The cryopanel can be made larger than the conventional one. Therefore, by attaching the activated carbon 9 to the inner surface of the second panel portion 8 and the area of the first panel portion 7 where the low boiling point gas such as oxygen, nitrogen and argon is condensed. Since the adsorbing area for adsorbing hydrogen gas by the activated carbon 9 can be increased, the exhaust rate as a whole can be further increased.

By eliminating the conventional shield panel, the cost can be reduced accordingly.
Since the structure is simple, assembly workability can be improved.

According to the second aspect of the present invention, since the first panel portion 7 and the second panel portion 8 are formed in a cylindrical shape, when the pump case 1 is formed in a cylindrical shape, the inner peripheral surface thereof is Since the respective panel portions 7 and 8 can be formed along the surface, the surface area can be increased more efficiently while simplifying the structure.

According to the third aspect of the present invention, the first panel portion 7 and the second panel portion 8 are formed by the continuous tubular member 51, and the mounting portion 6 formed of the plate member 52 inside the tubular member 51. Since the above is fixed, the axial length of each panel portion 7, 8 can be freely set to a desired length by arbitrarily setting the mounting position of the plate member 52 to the tubular member 51. Therefore, water, argon, which is exhausted by the condensation action,
It is possible to variously set the balance between the exhaust performance of gas such as nitrogen and the exhaust performance of gas such as hydrogen exhausted by the adsorption action of the activated carbon 9 according to the purpose.

According to the fourth aspect of the present invention, the bottom portions 53a, 53a of the two bottomed tubular members 53, 53 are butted, and the butted portion serves as the mounting portion 6, and the tubular portions 53b, 5 are provided.
Since 3b is composed of the first panel portion 7 and the second panel portion 8, respectively, the bottom portions 53a of the bottomed tubular members 53, 53,
Since the cryopanel can be formed only by abutting and fixing 53a, the processing can be simplified, and the diameter and the tube length of the first panel portion 7 and the second panel portion 8 can be individually set. Multiple types of cryopanels can be formed by combining them.

According to the fifth aspect of the present invention, the first panel portion 7 and the second panel portion 8 are composed of a plurality of plate-shaped members 54, and these plate-shaped members 54 are provided on the outer periphery of the mounting portion 6. Since the parts are radially provided at a predetermined interval in the circumferential direction, the low boiling point gas is not adsorbed from the inner part of the first panel part 7 condensed by the gap formed between the plate-like members 54. Since the hydrogen gas can easily reach the inner part of the second panel part 8, the hydrogen gas can be favorably adsorbed by the activated carbon for adsorbing hydrogen in the second panel part 8. The pumping speed can be increased.

Further, since each member constituting the cryopump can be formed by a plate-shaped member, such a special mold is required when forming a tubular member, as compared with the case where a special mold is required. Since it is not necessary and the plate members 54 can be easily fixed to the mounting portion 6, the processing can be further facilitated and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a cryopump showing a first embodiment.

FIG. 2 is a sectional view of a cryopanel showing a second embodiment.

FIG. 3 is a perspective view of a cryopanel showing a third embodiment.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

 2 heat station 3 refrigerator 5 cryopanel 51 tubular member 52 plate member 53 bottomed tubular member 53a bottom portion 53b tubular portion 54 plate member 6 mounting portion 7 first panel portion 8 second panel portion 9 activated carbon

Claims (5)

[Claims] 1. A cryopanel which is installed in a pump case (1) and is attached to a heat station (2) of a refrigerator (3) to condense and adsorb gas, the cryopanel being attached to the heat station (2). A mounting part (6) extending outward of the heat station (2), and a first panel part (7) projecting to one side in the axial direction of the refrigerator (3) at an outer peripheral part of the mounting part (6). And a second panel portion (8) having an activated carbon (9) adhered to the inner surface of the attachment portion (6), which protrudes to the other side in the axial direction of the refrigerator (3) and is attached to the inner surface. The characteristic cryopanel. 2. The cryopanel according to claim 1, wherein the first panel portion (7) and the second panel portion (8) are formed in a tubular shape. 3. A mounting portion comprising a first panel portion (7) and a second panel portion (8) formed by a continuous tubular member (51), and a plate member (52) inside the tubular member (51). (6)
The cryopanel according to claim 1, wherein the cryopanel is fixed. 4. The bottom parts (53a) (53a) of two bottomed tubular members (53) (53) are butted against each other, and the butted parts serve as mounting parts (6), and the respective tubular parts (53b). The cryopanel according to claim 1 or 2, wherein the (53b) comprises a first panel portion (7) and a second panel portion (8), respectively. 5. The first panel part (7) and the second panel part (8) are composed of a plurality of plate-shaped members (54), and these plate-shaped members (54) are provided on the outer peripheral part of the mounting part (6). The cryopanel according to claim 1, wherein the cryopanels are provided radially at predetermined intervals in the circumferential direction.