Air curtain device for wafer cases

Abstract

The air curtain device for a wafer case has a casing, the casing has an internal space, at least one first gas guide plate is provided in the internal space, the first gas guide plate has a first gas guide area, the first gas guide area is provided with a plurality of first gas guide holes, and a second gas guide plate is provided at an end of the internal space, the second gas guide plate has a second gas guide area, the second gas guide area has a plurality of second gas guide holes, the area of ​​the first gas guide area is smaller than the area of ​​the second gas guide area, the number of the second gas guide holes is greater than the number of the first gas guide holes, and the total area of ​​each second gas guide hole on the second gas guide plate is greater than the total area of ​​each first gas guide hole on the first gas guide plate.

Description

[Technical field]

[0001] The present invention relates to a wafer case, and more particularly to an air curtain device for a wafer case. [Background technology]

[0002] A wafer case (Front Opening Unified Pod: FOUP) is a container used in semiconductor manufacturing processes to protect, transport and store wafers, and its most important function is to prevent the wafers inside from being contaminated by particles and moisture from the external environment while being transported between different production equipment. When the wafer case is transported to the wafer case load port connected to the equipment front end modules (EFEM) of the equipment and the front door of the wafer case is opened in preparation for the manufacturing process, the air curtain device installed above the wafer case load port door in the EFEM blows clean, dry air downward to form an invisible wall that blocks the opening of the case, preventing particles and moisture from inside the EFEM from entering the case while the wafer is being transported to the manufacturing process space.

[0003] Wafers have very high requirements for low levels of particle contamination and moisture in the environment, and if the above-mentioned air curtain device does not emit a laminar flow in a straight line but emits a turbulent flow with a disturbed flow direction, particles outside the case and gas containing a large amount of moisture will be caught in the case, causing contamination and defeating the original purpose of preventing particles and moisture from entering the wafer case (FOUP).

[0004] Conventional air curtain devices have an air hole at the top that is connected to the inside of the air curtain device, and have a horizontal, elongated space inside. Gas is transported to the space of the air curtain device through the air hole to form an air flow, and the space has a plurality of air vents arranged vertically at intervals. When the air flow is ejected through these air vents, an air curtain is formed. However, after the air flow enters the space, it is quickly ejected from these air vents, and regardless of the structural arrangement, the guided flow of the ejected air flow is formed into a linear laminar flow. When the air flow is ejected radially through these air vents, the air flows interfere with each other and the flow direction is disturbed, and the flow direction formed after the air flow is ejected is disturbed and turbulent, which is a drawback in that particles and gas containing a large amount of moisture in the EFEM are caught up in the wafer case. Summary of the Invention

[0005] The primary objective of the present invention is to provide an air curtain device for a wafer case that blows clean, dry gas in a manner that approximates laminar flow, maximizing the reduction in turbulence formation, and preventing moisture and particles in the gas flowing within the EFEM from being entrained in the wafer case.

[0006] In order to achieve the above-mentioned object, the present invention provides an air curtain device for a wafer case, which comprises a casing, at least one first gas guide plate and a second gas guide plate. The casing has an interior space, at least one air intake port communicating with the interior space, and an air exhaust port communicating with the air intake port and the interior space. At least one first gas guide plate is provided in the interior space, the first gas guide plate having a first gas guide area, the first gas guide area having a plurality of first gas guide holes. The second gas guide plate is provided at an end of the internal space adjacent to the exhaust port, the second gas guide plate having a second gas guide area vertically opposed to the first gas guide area, and the second gas guide area has a plurality of second gas guide holes. An area of ​​the first gas guide area is smaller than an area of ​​the second gas guide area, the number of the second gas guide holes is greater than the number of the first gas guide holes, and the total area of ​​each of the second gas guide holes on the second gas guide plate is greater than the total area of ​​each of the first gas guide holes on the first gas guide plate. (Implementation method)

[0007] As shown in Figures 1 to 6, a first embodiment of an air curtain device for a wafer case provided by the present invention comprises a casing 1, at least one first gas guide plate 2, and a second gas guide plate 3.

[0008] The casing 1 extends in the longitudinal direction and is molded as a single unit, and is configured by combining a front plate member 11 and a rear plate member 12. The casing 1 encloses an internal space 13. The air curtain device is installed above the door of the wafer case load port 8 in the Equipment Front End Modules (EFEM).

[0009] In the first embodiment, the cross section of the casing 1 divides the internal space 13 into a first gas space 131 having a T-shape and a second gas space 132 communicating with the first gas space 131. A plurality of step portions 14 are formed on both side walls inside the second gas space 132 of the casing 1, which are expanded outward from top to bottom and are symmetrical to each other, forming a staircase shape. The top surface of the casing 1 has two intake ports 15 communicating with the first gas space 131. The bottom end of the casing 1 has an exhaust port 16 communicating with the second gas space 132. As shown in FIG. 6, the casing 1 is manufactured by a structure of a plurality of detachable overlapping blocks, but the present invention is not limited thereto.

[0010] The first gas guide plate 2 extends in the longitudinal direction and is disposed in the second gas space 132. The first gas guide plate 2 has a first gas guide area 21 extending in the longitudinal direction. The first gas guide area 21 is provided with a plurality of first gas guide holes 22 oriented vertically. In this embodiment, the number of the first gas guide plates 2 is three, and the three first gas guide plates 2 are opposed to each other vertically, and the area of ​​the first gas guide area 21 located at the upper side is smaller than that of the first gas guide area 21 located at the lower side. The widths of the three first gas guide plates 2 are such that the intervals between the mutually symmetrical step portions 14 are equal, and the three first gas guide plates 2 are combined with each other. In this embodiment, the multiple fixing members 4 are formed by screws, and each fixing member 4 is inserted from the bottom to the top on both outer sides of the three first gas guide areas 21, and the three first gas guide plates 2 are screwed onto the corresponding step portions 14.

[0011] The second gas guide plate 3 extends in the longitudinal direction and is provided at the end adjacent to the exhaust port 16 of the second gas space 132, and is disposed opposite to each of the first gas guide plates 2. The second gas guide plate 3 has a second gas guide area 31 which is vertically opposed to the first gas guide area 21 and extends in the longitudinal direction. The area of ​​the first gas guide area 21 is smaller than that of the second gas guide area 31. The second gas guide area 31 has a plurality of vertical second gas guide holes 32. The width of the second gas guide plate 3 is located at the lowest position, and the mutually symmetrical step portions 14 are equally spaced and combined with each other. Each fixing member 4 is inserted from the bottom to the top on both outer sides of the second gas guide area 31, and the second gas guide plate 3 is screwed onto the corresponding step portion 14.

[0012] As shown in FIG. 4, the number of second gas guide holes 32 provided by the present invention is greater than the number of first gas guide holes 22, and the total area of ​​each second gas guide hole 32 on the second gas guide plate 3 is greater than the total area of ​​each first gas guide hole 22 on the first gas guide plate 2. The number and total area of ​​each first gas guide hole 22 and each second gas guide hole 32 described above are such that, compared to a single first gas guide plate 2 and second gas guide plate 3, the fewer the number of gas guide holes and the smaller the total area distributed on the gas guide plate, the faster the flow rate of the airflow and the lower the uniformity. On the other hand, the more the number of gas guide holes and the larger the total area distributed on the gas guide plate, the slower the flow rate of the airflow and the higher the uniformity. Therefore, the flow rate of the airflow passing through the first gas guide plate 2 is faster, and the uniformity of the airflow passing through the second gas guide plate 3 is higher.

[0013] In addition, the two intake ports 15 of the casing 1 are connected to the intake pipes 6, respectively. Each gas guide pipe 5 is perforated at its upper end to introduce clean, dry gas, and has an outlet 51 at its lower end. Each gas guide pipe 5 extends from its outlet 51 into the intake port 15, and each outlet 51 communicates with the first gas space 131, so that the clean, dry gas is introduced into the internal space 13 of the casing 1 through the intake port 15, and sent to the exhaust port 16 through each first gas guide hole 22 and each second gas guide hole 32.

[0014] It is particularly noted here that the first gas space 131, which has a T-shaped cross section, allows the gas to be mixed thoroughly in the first gas space 131 first, and the gas is conveyed to the first gas space 131 without being directly and quickly discharged downward, thereby reducing the flow rate of the airflow. The cross section of the second gas space 132 of the casing 1 has a stepped shape, and the intervals of the step portions 14 gradually increase from top to bottom, so that the space of the second gas space 132 also gradually increases. When the gas flows into the second gas space 132 through the first gas guide holes 22 of each first gas guide plate 2, it sequentially flows into the step portions 14 with gradually increasing intervals, and similarly the gas is thoroughly mixed in the second gas space 132. When the gas hits the side wall of the second gas space 132, the gas is repelled and thoroughly mixed with each other. As one goes downward, the number of gas guide holes on the gas guide plate increases and the total area of ​​the gas guide holes distributed on the gas guide plate becomes larger. As the gas passes through the first gas guide plate 2 and the second gas guide plate 3 in the internal space 13, the gas is aligned to form airflows with different flow velocities and uniformities.

[0015] As can be seen from the above description of the structure of the present invention, when clean and dry gas is introduced into the casing 1 through the gas guide pipe 5, as shown in FIG. 5, the gas is first injected into the first gas space 131 through each of the outlets 51 to form an airflow. Since the cross section of the first gas space 131 is T-shaped, the airflow in the first gas space 131 is first mixed thoroughly in the first gas space 131 for a certain period of time, and then injected into the second gas space 132 through the first gas guide hole 22 which is located at the top of the second gas space 132 and has a circular shape. After passing through the first gas guide hole 22 which has a circular shape, the flow rate of the airflow is accelerated because the number of gas guide holes is small and the total area distributed on the gas guide plate is small.

[0016] Next, when the airflow continues to flow through the first gas guide holes 22 on the first gas guide plate 2 between the uppermost first gas guide plate 2 and the second gas guide plate 3, the number of the first gas guide holes 22 on the first gas guide plate 2 increases as it goes downward, and the total area of ​​the first gas guide holes 22 distributed on the first gas guide plate 2 increases (that is, when observed from top to bottom, the number and total area of ​​the first gas guide holes 22 on the uppermost first gas guide plate 2 are smaller than those of the intermediate first gas guide plate 2, and then the number and total area of ​​the first gas guide holes 22 on the intermediate first gas guide plate 2 are smaller than those of the lowermost first gas guide plate 2). After the accelerated airflow also slows down and is regulated for a certain period of time, the uniformity increases, and the airflow is regulated and flows in a linear downward direction.

[0017] When the airflow passes through the second gas guide hole 32 adjacent to the exhaust port 16, the number and total area of ​​each of the second gas guide holes 32 distributed on the second gas guide plate 3 are greater than the number and total area of ​​each of the first gas guide holes 22 distributed on the first gas guide plate 2, and when the airflow passes through the second gas guide area 31, the uniformity of the airflow can be further improved and the airflow is organized and flows uniformly downward in a straight line.When the airflow is blown out to the outside through the exhaust port 16, it flows uniformly in a straight line, and finally passes through the exhaust port 16 and a uniform airflow flowing in a straight line is discharged.

[0018] The feature of the present invention is that the flow path structure is designed so that the airflow passes through a number of gas guide plates to generate a straightening effect, and the number of gas guide holes on the gas guide plate increases as it goes downward, and the total area of ​​the gas guide holes distributed on the gas guide plate becomes larger. When the airflow passes through each of the first gas guide plate 2 and the second gas guide plate 3 in the internal space 13, it is straightened into airflows with different flow speeds and uniformity, and when it finally passes through the second gas guide hole 32, the uniformity of the airflow is increased, it is uniformly straightened and flows in a straight direction, and the airflow discharged through the exhaust port 16 has an appropriate speed, is uniformly distributed and flows in a straight direction, which can reliably block moisture and particles and prevent them from being caught in the wafer case.

[0019] As shown in FIG. 7, the second embodiment of the air curtain device for a wafer case provided by the present invention is different from the first embodiment in that the first gas space 131a is linear according to the cross section of the casing 1, and the gas is not mixed in the first gas space 131a and directly and quickly discharged downward, but when the gas is transported to the first gas space 131a, the air flow speed is reduced and mixed, thereby achieving the effect of increasing uniformity.

[0020] As shown in Figs. 8 and 9, the third embodiment of the air curtain device for a wafer case provided by the present invention is different from the first embodiment in that both side walls inside the second gas space 61 of the casing 6 are provided with insertion grooves 62 that are inserted corresponding to both sides of the three first gas guide plates 2b and the two second gas guide plates 3b. Each fixing member 4 is inserted outside the three first gas guide regions 21b and the two second gas guide regions 31b, and the three first gas guide plates 2b and the two second gas guide plates 3b are screwed onto the corresponding step portions 63. By passing the airflow through a number of gas guide plates to generate a rectifying effect, the uniformity of the airflow is improved and the rectifying is uniform, and the airflow flows in a straight line, which also functions to reliably block particles and moisture, and the airflow discharged through the exhaust port 16 is uniformly distributed at an appropriate speed and flows in a straight line, which also reliably blocks moisture and particles, and prevents moisture and particles from being caught in the wafer case.

[0021] As shown in Figs. 10 and 11, the fourth embodiment of the air curtain device for a wafer case provided by the present invention is different from the first embodiment in that the present invention further includes a plurality of gas guide assemblies 7. Each gas guide assembly 7 is composed of two spacers 71 and two first gas guide plates 72, or two spacers 71 and two second gas guide plates 73. The two spacers 71 are provided on both sides of the two first gas guide plates 72 or the two second gas guide plates 73, respectively, and are located between the corresponding two first gas guide plates 72 or the two second gas guide plates 73, and each fixing member 4 screws each gas guide assembly 7 onto the corresponding step portion 14. By passing the airflow through a number of gas guide plates to generate a rectifying effect, the fourth embodiment of the present invention performs the same function as the first embodiment, and similarly, it can reliably block moisture and particles and prevent moisture and particles from being caught in the wafer case.

[0022] It is particularly noted here that the structure of the second embodiment described above may be combined with the structure of the first, second or fourth embodiment shown in FIG. 1, but the present invention is not limited thereto. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view of a first embodiment of the present invention mounted on a wafer case load port. [Diagram 2] FIG. 2 is an exploded perspective view of the first embodiment of the present invention. [Diagram 3] FIG. 3 is a side view of the gas guide plate according to the first embodiment of the present invention in a state in which the casing internal space is extracted. [Figure 4] FIG. 4 is a plan view of the first gas guide plate and the second gas guide plate of the first embodiment of the present invention. [Diagram 5] FIG. 5 is a diagram showing a state in which the first embodiment of the present invention is used. [Figure 6] FIG. 6 is an exploded perspective view of the casing of the present invention having a detachable overlapping block structure. [Figure 7]FIG. 7 is a side view of the internal space of a casing according to a second embodiment of the present invention. [Figure 8] FIG. 8 is an exploded perspective view of a third embodiment of the present invention. [Figure 9] FIG. 9 is a side view of the internal space of a casing according to a third embodiment of the present invention. [Figure 10] FIG. 10 is an exploded perspective view of the fourth embodiment of the present invention. [Figure 11] FIG. 11 is a side view of the internal space of a casing according to a fourth embodiment of the present invention. [Explanation of symbols]

[0024] 1 Casing 11 Front plate member 12 Rear plate member 13. Interior Space 131 First Gas Space 131a First Gas Space 132 Second Gas Space 14 Step section 15 Air Intake 16 Exhaust port 2. First gas guide plate 2b First gas guide plate 21 first gas guide region 21b first gas guide region 22 First gas guide hole 3 Second gas guide plate 3b Second gas guide plate 31 second gas guide area 31b second gas guide region 32 Second gas guide hole 4 Fixing member 5 Gas guide pipe 51 Exit 6 Casing 61 Second Gas Space 62 Insert groove 63 Step section 7 Gas Guiding Assembly 71 Spacer 72 First Gas Guide Plate 73 Second Gas Guide Plate 8 Wafer Case Load Port

Claims

1. An air curtain device for a wafer case, comprising a casing, at least one first gas guide plate, and a second gas guide plate, The casing has an internal space, at least one intake port communicating with the internal space, and an exhaust port communicating with the intake port and the internal space, At least one first gas guide plate is provided in the internal space, the first gas guide plate having a first gas guide area, the first gas guide area having a plurality of first gas guide holes; the second gas guide plate is provided at an end of the internal space adjacent to the exhaust port, the second gas guide plate has a second gas guide area facing the first gas guide area above and below, the second gas guide area having a plurality of second gas guide holes; an area of ​​the first gas guide area is smaller than an area of ​​the second gas guide area, the number of the second gas guide holes is greater than the number of the first gas guide holes, and the total area of ​​each of the second gas guide holes on the second gas guide plate is greater than the total area of ​​each of the first gas guide holes on the first gas guide plate; An air curtain device for a wafer case, characterized in that the internal space is divided into a first gas space and a second gas space communicating with the first gas space by the cross section of the casing, and a plurality of mutually symmetrical step portions are formed on both side walls inside the second gas space of the casing, each of which expands outward from top to bottom, forming a staircase-like shape.

2. 2. The air curtain device for a wafer case as described in claim 1, wherein the number of the first gas guide plates is three, a plurality of fixing members are inserted on both outsides of the three first gas guide areas and the three second gas guide areas, and the three first gas guide plates and the three second gas guide plates are fixed on symmetrical steps, respectively.

3. 2. The air curtain device for a wafer case according to claim 1, wherein the number of the first gas guide plates is three, and both side walls inside the second gas space of the casing are provided with insertion grooves corresponding to both sides of the three first gas guide plates and the two second gas guide plates, respectively, and a plurality of fixing members are inserted on both outsides of the three first gas guide areas and the two second gas guide areas, respectively, and the three first gas guide plates and the two second gas guide plates are fixed on the symmetrical step portions.

4. Further comprising a plurality of gas directing assemblies; each of the gas guide assemblies is composed of two spacers and two of the first gas guide plates or two of the spacers and two of the second gas guide plates; 2. The air curtain device for a wafer case according to claim 1, wherein the two spacers are provided on both sides of the two first gas guide plates or the two second gas guide plates, respectively, and are positioned between the corresponding two first gas guide plates or the corresponding two second gas guide plates, and each of a plurality of fixing members fixes each of the gas guide assemblies on the corresponding step portion.

5. 2. The air curtain device for a wafer case according to claim 1, wherein the casing is integrally formed.

6. 2. The air curtain device for a wafer case according to claim 1, wherein the casing is made of a plurality of detachable overlapping blocks.

7. 2. The air curtain device for a wafer case as described in claim 1, wherein a gas guide pipe is connected to the air intake of the casing, which introduces clean, dry gas into the internal space of the casing through the air intake and exhausts it from the exhaust port.

8. 2. The air curtain device for a wafer case according to claim 1, wherein the first gas space has a T-shape according to a cross section of the casing.

9. 2. The air curtain device for a wafer case according to claim 1, wherein the first gas space has a linear shape according to a cross section of the casing.

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