Patent Application
20100032050
(1) Field of the Invention
The present invention relates to a nozzle which introduces gas into a container for purging the inside of the container, and particularly relates to a nozzle which introduces gas without contacting the container.
(2) Description of the Related Art
In manufacturing process of semiconductor devices such as LSI, wafers, glass substrates, reticles and others need to be stored such that they are not deteriorated or degenerated. For example, the wafers need to be stored in low oxygen atmosphere to prevent oxidization, and the reticles need to be stored in an atmosphere where moisture (H2O) is removed in order to suppress the growth of haze. Further, it is necessary to avoid the particles (fine dust) from adhering on the wafers and others as much as possible. For this reason, in many cases, the wafers are stored in a container which is filled with a clean gas composed of a type of gas suitable for the stored object.
However, as disclosed in Japanese Unexamined Patent Application Publication No. 2001-31212, there are cases where it is necessary to sort the stored wafers, ranging multiple containers. In such a case, it is necessary to open the containers. Thus, a process known as “purging” is performed in order to maintain high cleanliness of the container by introducing clean gas into the open container to keep the pressure in the container more positive than the atmosphere outside of the container.
Furthermore, it has been considered that storing the reticles 30 and others in a container where the purging is constantly performed causes less contamination of the reticles and others than the storage in a sealed container, since the reticles and others are stored for a relatively long period of time. Accordingly, there are purge apparatuses which can constantly purge the container with clean gas.
However, it has been known that the stored wafers and reticles are contaminated with the particles on rare occasions, even when a conventional purge apparatus is used. After the devoted research and diligent effort, the inventors of the present invention have reached the finding that the rare contaminations with the particles are caused by the purge apparatus. Furthermore, the inventors also found out that, since the container placed in the purge apparatus and the nozzle which discharges the gas into the container contact each other, the friction and impact between the container and the nozzle form the particles; the particles subsequently contaminates the inside 10 of the container, flowing with the gas for purging.
The present invention has been conceived in view of the above findings, and it is an object of the present invention to provide a is nozzle which can introduce gas into a container efficiently, while introducing the gas into the container without contacting the container to prevent the particles from being formed.
In order to solve the problem, the nozzle according to the present invention is a nozzle which introduces gas into a container without contacting the container, the nozzle comprising: a main opening where the gas at a first flow rate is discharged; and a sub-opening which has a collar-shape surrounding the main opening, and where the gas at a second flow rate is discharged in a same direction as a direction of the gas discharged from the main opening.
This forms an air curtain around the main opening with the gas discharged from the sub-opening. Accordingly, it is possible to avoid the gas discharged from the main opening from leaking from the gap between the nozzle and the container expeditiously, allowing efficient introduction of the gas into the container.
According to the present invention, even when the container is repeatedly attached to and detached from the nozzle for purging the inside of the container, particles are not formed due to the contact of the container and the nozzle. Furthermore, it is possible to efficiently introduce the gas discharged from the nozzle into the container, which suppresses the amount of wasted gas.
The disclosure of Japanese Patent Application No. 2008-207392 filed on Aug. 11, 2008 including specification, drawings and claims is incorporated herein by reference in its entirety.
These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings that illustrate a specific embodiment of the invention. In the Drawings:
The following is the description of the embodiments of the present invention with reference to the drawings.
As shown in these drawings, the nozzle 100 includes a main opening 101, a sub-opening 102, a through-hole 103, a main tube 111, and a sub-tube 112.
The main tube 111 is a member which includes the main opening 101, and is a tube-shaped member where the gas for purging flows. In the first embodiment, the main tube 111 has a cylindrical shape, and the hollow part functions as the main opening 101.
The sub-opening 112 is a tube-shaped member arranged to surround the main tube 111, and to have a gap with the main tube 111. Furthermore, the gap formed between the sub-tube 112 and the main tube 111 functions as the sub-opening 102. In the first embodiment, the sub-tube 112 is a cylinder arranged to have a concentric circular structure with the main tube 111, and have an inner diameter slightly larger than the outside diameter of the main tube 111. Furthermore, a flange slightly projecting in the radial direction is formed at an end of the main tube 111; the spatial relationship of the sub-tube 112 with respect to the main tube 111 is fixed by engaging with the flange. Accordingly, the gap which functions as the sub-opening 102 is maintained between the main tube 111 and the sub-tube 112, surrounding the main tube 111 with a predetermined width.
Here, when the gas at the same pressure is introduced into the main opening 101 and the sub-opening 102, the width of the sub-opening 102 is determined such that a second flow rate which is the flow rate of the gas discharged from the sub-opening 102 is smaller than a first flow rate which is the flow rate of the gas discharged from the main opening 101. More specifically, the preferable width of the sub-opening 102 is approximately around 2.5% of the diameter of the main opening 101. For example, the preferable width of the sub-opening 102 is approximately 0.1 mm, when the diameter of the main opening 101 is 4 mm.
The through-hole 103 is a hole for introducing a part of the gas flowing in the main opening 101 into the sub-opening 102. In the first embodiment, the through-hole 103 is provided to pass through the surrounding wall of the main tube 111 from the main opening 101 to the sub-opening 102.
The through-hole 103 separates the gas passing though the main opening 101 (shown in the arrow in
Next, the usage of the nozzle 100 is described.
As shown in
The discharge unit 212 can detect whether or not the container 200 is placed on a predetermined position on the shelf plate 211, and can discharge the gas from the nozzle 100 when the container 200 is detected.
As shown in
The container 200 includes a guide 201 which is tapered in shape, at a part where the gas discharged from the sub-opening 102 hits.
The guide 201 can guide the gas discharged from the sub-opening 102 in a direction of the gas discharged from the main opening 101, and functions like a reflector which reflects the gas discharged from the sub-opening 102 towards the gas discharged from the main opening 101. With this structure, most of the gas discharged from the sub-opening 102 is introduced into the container 200 together with the gas discharged from the main opening 101, while pressing the gas discharged from the main opening 101.
Here, the discharge unit 212 detects that the container 200 is placed, and causes the gas at the first flow rate to be discharged from the main opening 101 of the nozzle 100. The gas flowing in the main opening 101 is introduced into the sub-opening 102 via the through-hole 103, and is discharged from the sub-opening 102 at the second flow rate. The gas discharged from the sub-opening 102 forms a thin layer of gas flow surrounding the main opening 101. The layer of gas flow is formed in the gap between the nozzle 100 and the container 200, and exists as if to seal the gap between the nozzle 100 and the container 200. This prevents the leak of the gas discharged from the main opening 101 from the gap between the nozzle 100 and the container 200, and most of the gas is introduced into the container 200. Note that, the part of the gas discharged from the sub-opening 102 leaks from the gap between the nozzle 100 and the container 200; however, the second flow rate discharged from the sub-opening 102 is smaller than the first flow rate discharged from the main opening 101. Accordingly, it is possible to prevent the amount of leak as a whole, which allows efficient introduction of the gas into the container even when there is a gap between the nozzle 100 and the container 200.
Next, another embodiment according to the present invention will be described.
As shown in these drawings, the nozzle 100 includes a main opening 101, a sub opening 102, a through-hole 103, a main tube 111, and a sub tube 112.
The external form of the main tube 111 has a circular truncated cone-shape, and the main opening 101 is provided along the central axis of the main tube 111.
The sub-tube 112 is a tube-shaped member including a circular truncated cone-shaped hole corresponding to the external form of the main tube 111. Furthermore, the gap formed between the sub-tube 112 and the main tube 111 functions as the sub-opening 102.
The sub-opening 102 has a tapered shape where the tip comes closer to the main opening 101 such that the sub-opening 102 can discharge the gas toward the main opening 101. More specifically, the sub-opening 102 has a shape where the diameter gradually decreases towards the tip.
The abovementioned shape of the sub-opening 102 suppresses the amount of gas discharged from the sub-opening 102 from leaking through the gap between the nozzle 100 and the container 200. Therefore, it is possible to introduce the gas into the container 200 more efficiently as a whole.
Note that the gas is gas used for purging the container 200, and the type of gas is not particularly limited. For example, when the container 200 to be purged is a container 200 for holding the reticles, clean, dry air is suitable for the gas to be used. This is because the reticles have the small risk of oxidation caused by air. Furthermore, when the container 200 to be purged is a container 200 for holding the wafers, inert gas such as nitrogen is suitable for the gas to be used. This is because the wafers have a high risk of oxidization. The clean gas refers to gas which has zero or small number of particles per unit volume in the gas. The gas may be gas such as air where several types of gasses are mixed, and may also be gas composed of a single type of gas.
Note that, “opening” referred to as the main opening 101 and the sub-opening 102 in Claims and the specification is a part which determines the direction of the gas being discharged. In other words, the term “opening” is used in a three-dimensional concept, not in a two-dimensional concept. Accordingly, the description “the opening has a taper-shape” indicates the three-dimensional circular space, whose diameter gradually decreases, and the main tube 111 and the sub-tube 112 forming the circular space.
Although only some exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention.
The present invention is applicable to a nozzle which introduces clean gas to a container for storing the objects that needs to avoid the contamination by the particles, such as the reticles, the wafers, and lo the glass substrates for display apparatuses.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-207392 | Aug 2008 | JP | national |
