JP2006274876A - Pump device and semiconductor manufacturing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pump device for reducing the possibility that metallic ions eluting out of a member such as a mechanical seal is mixed into transferred liquid. <P>SOLUTION: The pump device 10 comprises: a pump casing 16 having a suction port 12 sucking transport liquid P<SB>5</SB>therein and a discharge port 14 discharging transport liquid P<SB>6</SB>therefrom; a rotational shaft 22 connected with a driving source; and an impeller 18 connected with the rotational shaft 22. The pump device 10 further comprises: a shaft seal part 20 sealing the rotational shaft 22; an intermediate chamber 32 formed between the impeller 18 and the shaft seal part 20; an inlet port 38 introducing flushing liquid for flushing the shaft seal part 20; a discharge port 36 discharging at least part of the transport liquid and the flushing liquid from the intermediate chamber 32 to the outside; and an ion adsorption/restriction mechanism 30 adsorbing the ions in the flushing liquid. The ion adsorption/restriction mechanism 30 is disposed between the shaft seal part 20 and the intermediate chamber 32. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pump device, and more particularly to a pump device for transferring an extremely high purity active liquid in a semiconductor manufacturing system. The present invention also relates to a semiconductor manufacturing system using such a pump device.

  In order to manufacture a highly integrated semiconductor, it is necessary to maintain high purity of various liquids used in manufacturing and to keep the content of impurities extremely low. For example, in ultrapure water used in the cleaning process of semiconductor manufacturing, the amount of fine particles in units of 0.1 microns becomes a problem, and these fine particles greatly affect the yield of products. In particular, in such a pump for transferring ultrapure water, it is important to prevent wear particles generated from the sliding portion.

  In addition, with high integration of semiconductors and high performance of liquid crystals, the residual metal ion concentration in ultrapure water has become a major problem, and a metal ion content of 1 ppt (1 trillionth) or less is required. It has become so. Such metal ions are generated when the metal is dissolved by the action of ultrapure water in the wetted parts such as pumps, pipes and valves.

  FIG. 1 is a schematic diagram showing a conventional pump device 100. As shown in FIG. 1, the pump apparatus 100 includes a pump casing 106 having a suction port 102 and a discharge port 104, an impeller 108 accommodated in the pump casing 106, and a transfer liquid from the pump casing 106 that receives the pump casing 106. And a mechanical seal 110 that prevents it from flowing into the external space 106. A rotating shaft 112 connected to an electric motor (not shown) is coupled to the impeller 108, and the impeller 108 is rotated by driving the electric motor. The pump casing 106, the impeller 108, and the rotating shaft 112 are coated with a fluororesin, and metal ions are eluted from the pump casing 106, the impeller 108, and the rotating shaft 112 in a transfer liquid such as ultrapure water. Is prevented.

  Between the impeller 108 and the mechanical seal 110, bushes 114 and 116 as a throttle mechanism are arranged. An intermediate chamber 118 is formed between the bush 114 and the bush 116, and a mechanical seal chamber 120 is formed between the bush 116 and the mechanical seal 110. The intermediate chamber 118 is provided with a discharge port 122 communicating with the external space of the pump casing 106, and the mechanical seal chamber 120 is provided with an injection port 124 for introducing flushing liquid from the outside into the mechanical seal chamber 120.

The transfer liquid P ₁ is sucked from the suction port 102 of the pump casing 106, and most of the transfer liquid is pressurized by the rotating impeller 108 to become a flow P ₂ discharged from the discharge port 104. Here, since there are parts that cannot be coated with fluororesin in the mechanical seal 110 or the like, when high-purity ultrapure water is used, the dissolution behavior of the metal from these parts cannot be suppressed. It is extremely inconvenient for such metal ions is mixed into the transported liquid P _2. In order to solve such a problem, the pressure of the intermediate chamber 118 is set lower than that of the mechanical seal chamber 120. That is, the flushing liquid P ₄ introduced from the injection port 124 is discharged out of the pump device 100 together with the transfer liquid P ₃ flowing from the impeller 108 side to the intermediate chamber 118, and metal ions are transferred from the pump device 100. so that not mixed into P _2.

However, since the metal ions eluted from the mechanical seal 110 flow into the intermediate chamber 118 of the conventional pump device 100 as it is, the pressure is reduced when the pump device 100 is stopped (including when it is stopped due to a malfunction). by reversing, there is a possibility that the metal ions from the mechanical seal 110 is mixed and diffused in the transported liquid P ₂ from the discharge port 104. Further, it is necessary to keep the flushing liquid injected from the injection port 124 in a healthy state at all times, which is troublesome for maintenance of the pump device 100.

  The present invention has been made in view of such problems of the prior art, and provides a pump device capable of reducing the possibility that metal ions eluted from a member such as a mechanical seal are mixed into the transfer liquid. The first purpose.

  A second object of the present invention is to provide a semiconductor manufacturing system capable of preventing contamination at the molecular level when including a process using pure water or ultrapure water such as ultraprecision cleaning. .

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a pump device capable of reducing the possibility that metal ions eluted from a member such as a mechanical seal are mixed into the transfer liquid. The pump device includes a pump casing having a suction port for sucking the transfer liquid and a discharge port for discharging the transfer liquid, a rotary shaft connected to a drive source, and an impeller connected to the rotary shaft. . The impeller is accommodated in the pump casing. The pump device introduces a shaft seal portion for sealing the rotary shaft, an intermediate chamber formed between the impeller and the shaft seal portion, and a flushing liquid for flushing the shaft seal portion. A discharge port for discharging at least a part of the transfer liquid and the flushing liquid from the intermediate chamber, and an ion adsorption throttle mechanism for adsorbing ions in the flushing liquid. The ion adsorption throttle mechanism is disposed between the shaft seal and the intermediate chamber. The ion adsorption throttling mechanism can be composed of an ion exchange resin filter and a flinger attached to the rotating shaft.

  With such a configuration, when the flushing liquid passes through the ion adsorption throttle mechanism, extraneous foreign substances such as metal ions in the flushing liquid are adsorbed by the ion adsorption throttle mechanism. In this way, by reducing the absolute amount of foreign matter in the atmosphere around the ion adsorption throttle mechanism, it is possible to more reliably achieve cleanness.

  According to the 2nd aspect of this invention, the pump apparatus which can reduce a possibility that the metal ion eluted from members, such as a mechanical seal, mixes in a transfer liquid is provided. The pump device includes a pump casing having a suction port for sucking the transfer liquid and a discharge port for discharging the transfer liquid, a rotary shaft connected to a drive source, and an impeller connected to the rotary shaft. . The impeller is accommodated in the pump casing. The pump device introduces a shaft seal portion for sealing the rotary shaft, an intermediate chamber formed between the impeller and the shaft seal portion, and a flushing liquid for flushing the shaft seal portion. An injection port for discharging, at least a part of the transfer liquid and the flushing liquid from the intermediate chamber to the outside, and a circulation for circulating at least a part of the liquid discharged from the discharge port to the injection port And a purifier for purifying the liquid introduced into the injection port via the circulation line. An ion removal filter can be used as the purifier.

  With such a configuration, the flushing liquid can be purified by a purifier and the clean flushing liquid can be circulated, so that the possibility of contamination of the transfer liquid discharged from the discharge port can be reduced, and high reliability can be achieved. Obtainable. In addition, since the flushing liquid is always maintained in a clean state, the maintenance work can be saved.

  According to the third aspect of the present invention, there is provided a semiconductor manufacturing system capable of preventing contamination at a molecular level in the case of including a process using pure water or ultrapure water such as ultraprecision cleaning. The semiconductor manufacturing system includes the pump device and a semiconductor manufacturing unit that manufactures a semiconductor device using pure water or ultrapure water boosted by the pump device.

  According to the pump device of the present invention, it is possible to reduce the possibility that metal ions are mixed into a transfer liquid such as pure water or ultrapure water with a simple structure, and it is possible to maintain high productivity and cleanliness.

  Further, according to the semiconductor manufacturing system of the present invention, contamination at the molecular level can be prevented when a process using pure water or ultrapure water such as ultraprecision cleaning is included.

  Hereinafter, an embodiment of a pump device according to the present invention will be described in detail with reference to FIGS. 2 and 3. 2 and 3, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  2 and 3 are schematic views showing the pump device 10 according to one embodiment of the present invention. As shown in FIG. 2, the pump device 10 includes a pump casing 16 having a suction port 12 and a discharge port 14, an impeller 18 accommodated in the pump casing 16, and a transfer liquid from the pump casing 16 that receives the pump casing 16. 16 is provided with a mechanical seal 20 serving as a shaft seal portion that prevents it from flowing into the external space. A rotating shaft 22 connected to an electric motor (not shown) is coupled to the impeller 18, and the impeller 18 is rotated by driving the electric motor. The pump casing 16, the impeller 18, and the rotating shaft 22 are coated with a fluororesin, and metal ions are eluted from the pump casing 16, the impeller 18, and the rotating shaft 22 in a transfer liquid such as ultrapure water. Is prevented.

  Between the impeller 18 and the mechanical seal 20, a bush 24 as a throttle mechanism is disposed. Between the bush 24 and the mechanical seal 20, an ion adsorption throttle mechanism 30 including an ion exchange resin filter 26 and a flinger 28 is disposed. In the example shown in FIG. 2, three ion exchange resin filters 26 and two flinger 28 are arranged.

  An intermediate chamber 32 is formed between the bush 24 and the ion adsorption throttle mechanism 30, and a mechanical seal chamber 34 is formed between the ion adsorption throttle mechanism 30 and the mechanical seal 20. The intermediate chamber 32 is provided with a discharge port 36 communicating with the external space of the pump casing 16, and the mechanical seal chamber 34 is provided with an injection port 38 for introducing the flushing liquid from the outside into the mechanical seal chamber 34. For example, tap water is used as the flushing liquid.

The transfer liquid P ₅ is sucked from the suction port 12 of the pump casing 16, and most of the transfer liquid is pressurized by the impeller 18 rotating in the pump chamber 39 to become a flow P ₆ discharged from the discharge port 14. Here, since there are parts that cannot be coated with fluororesin in the mechanical seal 20 or the like, when high-purity ultrapure water is used, the dissolution behavior of metals from these parts cannot be suppressed. It is extremely inconvenient for such metal ions is mixed into the transported liquid P _6. In order to solve such a problem, the pressure of the intermediate chamber 32 is set lower than that of the mechanical seal chamber 34. That is, the flushing liquid P ₈ introduced from the injection port 38 is discharged out of the system of the pump device 10 together with the transfer liquid P ₇ flowing from the impeller 18 side to the intermediate chamber 32, and the metal ions are transferred from the discharge port 14. so as not mixed into the P _6.

  Further, when the flushing liquid passes through the ion adsorption throttle mechanism 30, extraneous foreign substances such as metal ions in the flushing liquid are adsorbed by the ion adsorption throttle mechanism 30. If the number of stages of the ion exchange resin filter 26 and the flinger 28 is increased, the performance can be further improved. Further, the ion exchange resin filter 26 and the flinger 28 may be combined so as to cover a desired combination of ions. Furthermore, an ion trap by electrolysis may be introduced into the ion adsorption throttle mechanism 30. Also, good results can be obtained even if a graft membrane or the like is used for the ion exchange resin filter 26.

  In this way, by reducing the absolute amount of foreign matter in the atmosphere around the ion adsorption throttle mechanism 30, it is possible to more surely achieve cleaning. Further, for example, when the pump device 10 is used in a semiconductor manufacturing system, foreign substances that are inconvenient for semiconductors such as metal ions in the flushing liquid can be captured and fixed by the ion adsorption throttle mechanism 30.

  As shown in FIG. 3, the discharge port 36 is connected to a small booster pump 44 via a pipe 40 and a pipe 42. Since the cleanliness of the booster pump may be relatively low, it can be configured at low cost. The booster pump 44 is connected to the water injection port 38 via a pipe 46, a purifier 48 such as an ion removal filter, and a pipe 50. As described above, the piping 40, the piping 42, the booster pump 44, the piping 46, the purifier 48, and the piping 50 form a circulation line that circulates at least a part of the liquid discharged from the discharge port 36 to the injection port 38. ing. That is, the liquid discharged from the discharge port 36 of the intermediate chamber 32 may be discharged out of the system through the valve 52, but a part of the liquid is boosted to a desired pressure by the booster pump 44 and supplied to the purifier 48. By passing the liquid, the liquid having a water quality that does not adversely affect the mechanical seal 20 can be introduced into the water injection port 38.

A flushing liquid (for example, tap water) is supplied to the pipe 50 via a valve 54. Since the transfer liquid is ultrapure water, the transfer liquid P ₇ from the pump chamber 39 is relatively clean, but the liquid exiting from the discharge port 36 of the intermediate chamber 32 is the initial flushing liquid and the mechanical seal chamber 34. Coming out with dirt. Therefore, greater the flushing liquid to the cleaner, the risk of contamination of the transported liquid P ₇ from the discharge port 14 is reduced, high reliability can be obtained. If necessary, a component analyzer 56 and a valve 58 for periodically inspecting components of the liquid discharged from the discharge port 36 of the intermediate chamber 32 may be connected to the pipe 40.

  Here, the pump device 10 described above can be incorporated in a semiconductor manufacturing system. That is, in a semiconductor manufacturing unit for manufacturing a semiconductor device, pure water or ultrapure water is often used, but the above-described pump device 20 is used as a pump for boosting the pure water or ultrapure water. Thus, for example, contamination at the molecular level can be prevented in ultraprecision cleaning.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

It is a schematic diagram which shows the conventional pump apparatus. It is a schematic diagram which shows the pump apparatus in one Embodiment of this invention. It is a block diagram which shows the structure of the pump apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pump apparatus 12 Suction port 14 Discharge port 16 Pump casing 18 Impeller 20 Mechanical seal 22 Rotating shaft 24 Bush 26 Ion exchange resin filter 28 Flinger 30 Ion adsorption throttling mechanism 32 Intermediate chamber 34 Mechanical seal chamber 36 Discharge port 38 Injection port 39 Pump Chamber 40, 42, 46, 50 Piping 44 Booster pump 48 Purifier 52, 54, 58 Valve 56 Component analyzer

Claims (5)

A pump casing having a suction port for sucking the transfer liquid and a discharge port for discharging the transfer liquid;
A rotating shaft coupled to a drive source;
An impeller housed inside the pump casing and connected to the rotating shaft;
A shaft seal portion for sealing the rotating shaft;
An intermediate chamber formed between the impeller and the shaft seal,
An injection port for introducing a flushing liquid for flushing the shaft seal;
A discharge port for discharging at least part of the transfer liquid and the flushing liquid from the intermediate chamber to the outside;
An ion adsorption throttle mechanism that is arranged between the shaft seal and the intermediate chamber and adsorbs ions in the flushing liquid;
A pump device comprising:   The pump device according to claim 1, wherein the ion adsorption throttle mechanism includes an ion exchange resin filter and a flinger attached to the rotating shaft. A pump casing having a suction port for sucking the transfer liquid and a discharge port for discharging the transfer liquid;
A rotating shaft coupled to a drive source;
An impeller housed inside the pump casing and connected to the rotating shaft;
A shaft seal portion for sealing the rotating shaft;
An intermediate chamber formed between the impeller and the shaft seal,
An injection port for introducing a flushing liquid for flushing the shaft seal;
A discharge port for discharging at least part of the transfer liquid and the flushing liquid from the intermediate chamber to the outside;
A circulation line for circulating at least part of the liquid discharged from the discharge port to the injection port;
A purifier for purifying the liquid introduced into the injection port via the circulation line;
A pump device comprising:   The pump device according to claim 3, wherein the purifier is an ion removal filter. A pump device according to any one of claims 1 to 4,
A semiconductor manufacturing unit for manufacturing a semiconductor device using pure water or ultrapure water boosted by the pump device;
A semiconductor manufacturing system comprising:

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