Air curtain device for wafer cassette

Abstract

A gas curtain device for a wafer box has a housing with an internal space defining a horizontal gas chamber, a curved gas chamber and a vertical gas chamber. At least one first gas guide plate is provided in the horizontal gas chamber and / or the curved gas chamber, and the first gas guide plate is provided with a plurality of first gas guide holes. A second gas guide plate is provided in the vertical gas chamber, and the second gas guide plate is provided with a plurality of second gas guide holes. The gas curtain device for the wafer box can make clean dry gas blow out in a close to laminar flow manner, maximize the reduction of the formation of turbulence, and avoid water vapor, dust and other impurities in the flowing gas in the front end module from being sucked into the wafer box.

Description

Technical Field

[0001] This invention relates to wafer cassettes, and more particularly to an air curtain device for a wafer cassette. Background Technology

[0002] A front-opening unified pod (FOUP) is a container used in semiconductor manufacturing to protect, transport, and store wafers. One of its most important functions is to prevent the wafers from being contaminated by dust and moisture from the external environment during transport between different production equipment. When the wafer pod is transported to the load port connected to the equipment front-end modules (EFEM) and ready for processing, a clean, dry airflow is sprayed downwards by an air curtain device located on the upper side of the load port door within the EFEM. This forms an invisible wall that blocks the entry of dust and moisture from the EFEM into the pod during transport to the process chamber.

[0003] Wafers have very high requirements for the level of low dust and moisture pollution in the environment. If the aforementioned air curtain device does not spray laminar flow in a straight direction, but rather turbulence with chaotic flow direction, it is very likely to entrain dust and gases with high moisture content outside the box into the box, causing pollution and thus losing the original purpose of preventing dust and moisture from entering the wafer box (FOUP).

[0004] As is commonly known, air curtain devices have an air hole at the top that connects to the interior of the air curtain device. The interior has a horizontal and elongated space. Gas is delivered to the space of the air curtain device through the air hole to form an airflow. There are a plurality of spaced and vertically arranged vents in the space. The airflow is ejected through the plurality of vents to form an air curtain. However, after entering the space, the airflow is quickly ejected through the plurality of vents. There is no structural configuration to guide the ejected airflow into a straight laminar flow. As a result, the airflow is ejected from the plurality of vents in a scattered manner, causing the airflow to interfere with each other and making its flow direction chaotic. This results in turbulent flow with chaotic flow direction after the airflow is ejected, which causes the dust and gas with high moisture content in the EFEM to be entrained into the wafer cell. Summary of the Invention

[0005] The main objective of this invention is to provide an air curtain device for a wafer cassette, which allows clean and dry gas to be blown out in a near-laminar flow manner, minimizing the formation of turbulence, so as to prevent water vapor, dust, etc. in the flowing gas in the front-end module of the device from being drawn into the wafer cassette.

[0006] To achieve the aforementioned objectives, the present invention provides an air curtain device for a wafer cassette, comprising:

[0007] A housing having an internal space, and defining a transverse air chamber, a curved air chamber communicating with the transverse air chamber and a vertical air chamber communicating with the curved air chamber according to the cross-section of the housing, the housing having at least one air inlet communicating with the transverse air chamber and an air outlet communicating with the vertical air chamber.

[0008] At least one first air guide plate is disposed in the transverse air chamber and / or the curved air chamber, and the first air guide plate is provided with a plurality of first air guide holes;

[0009] A second air guide plate is provided at one end of the vertical air chamber near the air outlet, and the second air guide plate is provided with a plurality of second air guide holes;

[0010] The number of the second air guide holes is greater than the number of the first air guide holes, and the total area of ​​the second air guide holes on the second air guide plate is greater than the total area of ​​the first air guide holes on the first air guide plate.

[0011] Preferably, the diameter of the cross-section at the very end of the vertical air chamber is larger than the diameter of the cross-section of the transverse air chamber and the diameter of the cross-section of the curved air chamber.

[0012] Preferably, the diameter of the cross-section of the curved air chamber is larger than the diameter of the cross-section of the transverse air chamber, and the diameter of the cross-section at the very end of the vertical air chamber is larger than the diameter of the cross-section of the curved air chamber.

[0013] Preferably, there are three first air guide plates, one of which is disposed in the transverse air chamber, and the other two are disposed in the curved air chamber.

[0014] Preferably, the curved air chamber is formed in a downward curved arc shape, with one of the other two first air guide plates located at one end of the curved air chamber in the horizontal direction and the other at one end of the curved air chamber in the vertical direction.

[0015] Preferably, the first air guide plate and the second air guide plate are replaceable structures, so as to change the number and total area of ​​the first air guide hole and the second air guide hole, thereby adjusting the flow rate and uniformity of the airflow when passing through the first air guide plate and the second air guide plate.

[0016] Preferably, the first air guide holes on the first air guide plate can be evenly or unevenly distributed to adjust the airflow effect.

[0017] Preferably, the housing is composed of a left plate, a right plate, and a plurality of partitions.

[0018] In another embodiment, the housing is formed by splicing together a left shell member and a right shell member.

[0019] In another embodiment, the housing is made in one piece. Attached Figure Description

[0020] Figure 1 This is a three-dimensional schematic diagram of the first embodiment of the present invention assembled on the wafer cassette loading port.

[0021] Figure 2 This is a three-dimensional exploded view of the first embodiment of the present invention.

[0022] Figure 3 This is a side view of the internal space of the housing after the air guide plate has been removed, according to the first embodiment of the present invention.

[0023] Figure 4 This is a cross-sectional schematic diagram of the first embodiment of the present invention.

[0024] Figure 5 This is a plan view of the first air guide plate and the second air guide plate according to the first embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the usage state of the first embodiment of the present invention.

[0026] Figure 7 This is a side view of the internal space of the housing according to the second embodiment of the present invention.

[0027] Figure 8 This is a side view of the internal space of the housing according to the third embodiment of the present invention. Detailed Implementation

[0028] Please see Figures 1 to 6 The image shows a first embodiment of the air curtain device for a wafer cassette provided by the present invention, which comprises a housing 1, at least one air guide plate 2, and a second air guide plate 3, wherein:

[0029] The housing 1 is composed of a left plate 11, a right plate 12, and a plurality of partitions 13, combined with a front plate 14 and a rear plate 15, and the housing 1 encloses an internal space 16. The air curtain device is located on the upper side of the door of the wafer cassette loading port 7 in an Equipment Front End Module (EFEM).

[0030] Following on, such as Figure 3As shown, the internal space 16 is defined by the cross-section of the housing 1 as having a transverse air chamber 161, a curved air chamber 162 communicating with the transverse air chamber 161, and a vertical air chamber 163 communicating with the curved air chamber 162. The diameter of the cross-section at the far end of the vertical air chamber 163 is larger than the diameter of the cross-section of the transverse air chamber 161 and the diameter of the cross-section of the curved air chamber 162. In this embodiment, the diameter D2 of the cross-section of the curved air chamber 162 is larger than the diameter D1 of the cross-section of the transverse air chamber 161, and the diameter D3 of the cross-section at the far end of the vertical air chamber 163 is larger than the diameter D2 of the cross-section of the curved air chamber 162. The top surface of the left plate 11 of the housing 1 has two air inlets 17 communicating with the transverse air chamber 161, and the bottom end of the housing 1 has an air outlet 18 communicating with the vertical air chamber 163.

[0031] The first air guide plate 2 is disposed in the transverse air chamber 161 and / or the curved air chamber 162. The first air guide plate 2 has a plurality of first air guide holes 21. In this embodiment, the number of the first air guide plates 2 is three. One of the first air guide plates 2 is disposed on one of the partition plates 13 and located in the transverse air chamber 161, while the other two first air guide plates 2 are located in the curved air chamber 162. The curved air chamber 162 is formed into a downward curved arc shape. One of the other two first air guide plates 2 is located at one end of the curved air chamber 162 in the horizontal direction, and the other is located at one end of the curved air chamber 162 in the vertical direction. In this first embodiment, the other two first air guide plates 2 are replaceable.

[0032] The second air guide plate 3 is located at one end of the vertical air chamber 163 near the air outlet 18. The second air guide plate 3 has a plurality of longitudinal second air guide holes 31, each of which is circular and has a replaceable structure.

[0033] Furthermore, such as Figure 4 As shown, there are three first air guide plates 2, which divide the internal space 16 into at least one first air chamber 51, one second air chamber 52, one third air chamber 53, and one fourth air chamber 54. The first air chamber 51 is connected to the air inlet 17, and the fourth air chamber 54 is connected to the air outlet 18. Based on the shape of each partition 13, the first air chamber 51, the second air chamber 52, and the third air chamber 53 are located at the same height and are horizontally adjacent to each other, while the fourth air chamber 54 is adjacent to the lower part of the third air chamber 53.

[0034] Furthermore, two of the first air guide plates 2 are arranged opposite each other, and the first air chamber 51 and the second air chamber 52 are connected horizontally through the first air guide hole 21 that runs through them. Similarly, the second air chamber 52 and the third air chamber 53 are connected horizontally. The other first air guide plate 2 is arranged opposite to the second air guide plate 3. Based on the shape of the curved air chamber 162, the third air chamber 53 is also curved downwards. The third air chamber 53 and the fourth air chamber 54 are connected vertically through the first air guide hole 21 that runs through the other first air guide plate 2.

[0035] In this embodiment, the first air guide hole 21 separating the first air chamber 51 and the second air chamber 52 is circular, while the first air guide holes 21 of the remaining first air guide plates 2 are grid-shaped. The grid-shaped air guide holes refer to a plurality of air guide holes arranged at intervals, each forming a vertically extending strip. Accordingly, when the airflow passes through the grid-shaped first air guide holes 21, it can generate a rectifying effect, ensuring that the airflow flows in a straight line. The three first air guide holes 21 can be circular or grid-shaped, without limiting the invention.

[0036] In addition, such as Figure 5 As shown, the number of second air guide holes 31 provided by the present invention is greater than the number of first air guide holes 21, and the total area of ​​each second air guide hole 31 on the second air guide plate 3 is greater than the total area of ​​each first air guide hole 21 on the first air guide plate 2. The number and total area of ​​each first air guide hole 21 and each second air guide hole 31 are compared with a single first air guide plate 2 and second air guide plate 3. The fewer the number of air guide holes and the smaller the total area distributed on the air guide plate, the faster the airflow velocity and the lower the uniformity. Conversely, the more air guide holes and the larger the total area distributed on the air guide plate, the slower the airflow velocity and the higher the uniformity. Therefore, the airflow velocity through the first air guide plate 2 is fast, while the airflow uniformity through the second air guide plate 3 is high. Furthermore, the first air guide plate 2 and the second air guide plate 3 are replaceable structures, which allow for changing the number and total area of ​​the first air guide hole 21 and the second air guide hole 31, thereby adjusting the airflow velocity and uniformity when the airflow passes through the first air guide plate 2 and the second air guide plate 3.

[0037] Furthermore, the second air guide holes 31 are evenly distributed on the second air guide plate 3, and the first air guide holes 21 are evenly or unevenly distributed on the first air guide plate 2. Similarly, by making the first air guide plate 2 a replaceable structure, the first air guide holes 21 can be evenly distributed on the first air guide plate 2, or unevenly distributed and concentrated at certain positions on the first air guide plate 2, thereby adjusting the airflow effect in the internal space 16.

[0038] In addition, an air inlet pipe 6 is connected to each of the two air inlets 17 of the housing 1. The upper end of each air inlet pipe 6 is open to allow the introduction of clean and dry gas, and the lower end of each air inlet pipe 6 has an outlet 61. Each air inlet pipe 6 extends into the air inlet 17 through its outlet 61, so that each outlet 61 is connected to the first air chamber 51.

[0039] It should be noted that the diameter D2 of the cross-section of the curved air chamber 162 is larger than the diameter D1 of the cross-section of the transverse air chamber 161, and the diameter D3 of the cross-section of the vertical air chamber 163 is larger than the diameter D2 of the cross-section of the curved air chamber 162. This allows the gas to flow sequentially through air chambers with progressively larger cross-sectional diameters. As a result, the gas velocity can be reduced when it is delivered to the internal space 16. Compared to a straight air chamber, the curved air chamber 162 allows the airflow to stay in the internal space 16 for a longer period of time. By matching the diameters of each cross-section with the curved air chamber 162, the airflow can be organized into different velocities and uniformities as it flows through the first air guide plate 2 and the second air guide plate 3 in the internal space 16. For example, in this embodiment, the airflow velocity is fast when it passes through the first air guide hole 21. Even if the velocity is slowed down by the curved air chamber 162, the airflow can still achieve a uniform and high airflow effect at a considerable speed when it passes through the second air guide hole 31.

[0040] With the structure of the present invention described above, when gas is introduced into the housing 1 through the inlet pipe 6, as... Figure 6 As shown, gas is first injected into the first air chamber 51 from each of the outlets 61 to form an airflow. The airflow in the first air chamber 51 is injected into the second air chamber 52 through the first circular air guide hole 21. When the airflow passes through the first circular air guide hole 21, the airflow speed will increase because the number of holes is small and the total area distributed on the air guide plate is small.

[0041] Next, the airflow is injected into the third air chamber 53 through one of the grid-shaped first air guide holes 21. Since the first air guide hole 21 is grid-shaped, the airflow is rectified into a horizontal flow state. Then, it turns downward along the shape of the third air chamber 53, so that the accelerated airflow can slow down and be regulated for a period of time to improve uniformity. Then, it is injected into the fourth air chamber 54 through another grid-shaped first air guide hole 21, so that the airflow is rectified into a downward flow state in a straight line.

[0042] Then, when the airflow passes through the second air guide hole 31 adjacent to the air outlet 18, since the number and total area of ​​the second air guide holes 31 distributed on the second air guide plate 3 are large, the airflow can improve the uniformity of the airflow and be rectified into a state of uniform downward flow in a straight line when it passes through the second air guide hole 31, so as to ensure that the airflow blown out to the outside through the air outlet 18 is uniformly flowed in a straight line. Finally, the uniform airflow flowing in a straight line is discharged through the air outlet 18.

[0043] The invention is characterized by a flow channel structure design that allows airflow to pass through four air guide plates to achieve a rectifying effect. By using the cross-sectional diameter of each air guide plate to match the curved air chamber 162, the airflow in the internal space 16 can be categorized into airflows with different velocities and uniformities as it flows through the first air guide plate 2 and the second air guide plate 3. Finally, when it flows through the second air guide hole 31, the uniformity of the airflow is improved and rectified into a uniform flow in a straight direction. This ensures that the airflow discharged through the air outlet 18 has a considerable speed, is evenly distributed, and flows in a straight direction, effectively blocking moisture and dust and preventing moisture and dust from being drawn into the wafer cassette.

[0044] And such Figure 7 The image shows a second embodiment of the air curtain device for a wafer cassette provided by the present invention. The difference between this second embodiment and the first embodiment is that, in this second embodiment, the housing 1a is formed by splicing together a left housing 11a and a right housing 12a, and the three first air guide plates 2a and the second air guide plates 3 are all replaceable structures to change the flow rate and uniformity of the airflow. The airflow passes through the four air guide plates and generates a rectification effect, which can also improve the uniformity of the airflow and rectify it to flow uniformly in a straight line. It can also effectively block dust and moisture, thereby ensuring that the airflow discharged through the air outlet 18 has a considerable speed and is evenly distributed and flows in a straight line. It can also effectively block moisture and dust and prevent moisture and dust from being drawn into the wafer cassette.

[0045] For example Figure 8 The image shows a third embodiment of the air curtain device for a wafer cassette provided by the present invention. The difference between this third embodiment and the first embodiment is that the housing 1b is integrally formed, and the three first air guide plates 2b and the second air guide plates 3 are all replaceable to change the flow rate and uniformity of the airflow. Similarly, the airflow passes through the four air guide plates to generate a rectification effect, which can perform the function of the first embodiment. This can effectively block water vapor and dust and prevent water vapor and dust from being drawn into the wafer cassette.

[0046] The above description describes the preferred embodiments of the present invention and the technical principles applied thereto. For those skilled in the art, any obvious changes such as equivalent transformations or simple substitutions based on the technical solutions of the present invention, without departing from the spirit and scope of the present invention, shall fall within the protection scope of the present invention.

Claims

1. An air curtain device for a wafer cassette, characterized in that, The system includes: a housing disposed outside the wafer cassette, adjacent to the front opening of the wafer cassette and corresponding to the upper part of the front opening; the housing having an internal space, and defining the internal space according to the cross-section of the housing as a transverse air chamber, a curved air chamber communicating with the transverse air chamber, and a vertical air chamber communicating with the curved air chamber; the housing having at least one air inlet communicating with the transverse air chamber and an air outlet communicating with the vertical air chamber, wherein the transverse air chamber, the curved air chamber, and the vertical air chamber are arranged sequentially along an airflow path; a multi-stage airflow regulation system disposed in the internal space of the housing, and composed of the transverse air chamber, the curved air chamber, the vertical air chamber, at least one first air guide plate, and a second air guide plate, for multi-stage regulation of the flow trajectory and flow cross-section of the airflow from the at least one air inlet to the air outlet; and at least one first air guide plate disposed in the transverse air chamber and / or the... In the curved air chamber, the first air guide plate is provided with a plurality of first air guide holes; a second air guide plate is provided at one end of the vertical air chamber near the air outlet, and the second air guide plate is provided with a plurality of second air guide holes; wherein, the at least one first air guide plate and the second air guide plate are separated from each other and spaced apart, and are located in different airflow adjustment stages of the multi-stage airflow adjustment system, the at least one first air guide plate is located upstream of the second air guide plate along the airflow path, so that the airflow first passes through the first air guide holes and then through the second air guide holes; wherein, the number of second air guide holes is greater than the number of first air guide holes, and the total area of ​​each second air guide hole on the second air guide plate is greater than the total area of ​​each first air guide hole on the first air guide plate; the airflow is ejected from above the front opening of the wafer cassette through the air outlet, generally downward, to form an air curtain near and covering the front opening, blocking external dust and moisture from entering the wafer cassette.

2. The air curtain device for a wafer cassette as described in claim 1, characterized in that, The diameter of the cross-section at the very end of the vertical air chamber is larger than the diameter of the cross-section of the horizontal air chamber and the diameter of the cross-section of the curved air chamber.

3. The air curtain device for the wafer cassette as described in claim 2, characterized in that, The diameter of the cross-section of the curved air chamber is larger than the diameter of the cross-section of the transverse air chamber, while the diameter of the cross-section at the very end of the vertical air chamber is larger than the diameter of the cross-section of the curved air chamber.

4. The air curtain device for a wafer cassette as described in claim 1, characterized in that, There are three first air guide plates, one of which is located in the transverse air chamber, while the other two are located in the curved air chamber.

5. The air curtain device for a wafer cassette as described in claim 4, characterized in that, The curved air chamber is formed in a downward curved arc shape. One of the other two first air guide plates is located at one end of the curved air chamber in the horizontal direction, and the other is located at one end of the curved air chamber in the vertical direction.

6. The air curtain device for a wafer cassette as described in claim 4, characterized in that, The first air guide plate and the second air guide plate are replaceable structures, which can be used to change the number and total area of ​​the first air guide hole and the second air guide hole, thereby adjusting the flow rate and uniformity of the airflow when passing through the first air guide plate and the second air guide plate.

7. The air curtain device for a wafer cassette as described in claim 6, characterized in that, The first air guide holes on the first air guide plate can be evenly or unevenly distributed to adjust the airflow effect.

8. The air curtain device for a wafer cassette as described in claim 1, characterized in that, The shell consists of a left plate, a right plate, and a plurality of partitions.

9. The air curtain device for a wafer cassette as described in claim 1, characterized in that, The shell is composed of a left shell and a right shell joined together.

10. The air curtain device for a wafer cassette as described in claim 1, characterized in that, The shell is made in one piece.

11. The air curtain device for a wafer cassette as claimed in claim 1, characterized in that, The transverse air chamber, the curved air chamber, and the vertical air chamber are arranged in sequence to guide the airflow introduced into the internal space of the housing through the at least one air inlet to the air outlet in sequence.

12. The air curtain device for a wafer cassette as described in claim 1, characterized in that, The at least one first air guide plate is located upstream of the second air guide plate along the airflow path, so that the airflow passes through the at least one first air guide plate before passing through the second air guide plate.

13. The air curtain device for a wafer cassette as described in claim 1, characterized in that, The number and total area of ​​the first and second air guide holes can be adjusted to regulate the flow rate and uniformity of the airflow passing through the first and second air guide plates.

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