US20080282500A1

US20080282500A1 - Nozzle and dust removing apparatus

Info

Publication number: US20080282500A1
Application number: US11/889,013
Authority: US
Inventors: Mitoshi Omagari
Original assignee: NEC LCD Technologies Ltd
Current assignee: Tianma Japan Ltd
Priority date: 2006-08-09
Filing date: 2007-08-08
Publication date: 2008-11-20
Also published as: JP2008036566A

Abstract

A nozzle for sucking dust includes an opening part which is disposed at an end of the nozzle, and is sucking air to suck dust; and a turbulent air flow generating part which is disposed near the opening part to generates a turbulent air flow in the sucked air.

Description

RELATED APPLICATIONS

This application is based on Japanese Patent Application No. JP 2006-216460 filed on Aug. 9, 2006, and including a specification, claims, drawings and summary. The disclosure of the above Japanese Patent Application is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a nozzle and a dust removing apparatus and particularly, relates to a nozzle and a dust removing apparatus which collect dust, dirt, particles, foreign substances or the like by sucking air.
2. Description of the Related Art
A manufacturing process of products such as a liquid crystal display panel and a semiconductor needs a clean environment for preventing dust from attaching to substrate to be used for such products. It is required to manufacture substrates such as liquid crystal display panel substrates, glass substrates and semiconductor substrates in a clean condition, i.e., a dust-free condition. This is because a product in which a substrate with dust is used is likely to become a defective product. Here, the dust means dirt, fine particles, foreign substances or the like. Therefore, countermeasures for preventing dust generation from a dust source, and improvement in dust removing methods for removing dust on a substrate surface are required.
Two types of a dust removing method are widely known. One is a wet method in which a substrate is washed by a washer, and the other is a dry method which is used in a process to which the wet method can not be applied because of a structure of a substrate. According to the dry method, dust which adheres to a surface of a substrate is removed through sucking air. There exist two typical examples of the dry method. One is a cleaner type in which compressed air is blown to a surface of a substrate and then, dust blown off is sucked with air. The other is a suction type in which dust is only sucked.
A dust removing apparatus of the cleaner type is disclosed, for example, in Japanese Patent Application Laid-Open No. 2005-131502. FIG. 6A and FIG. 6B show a cylindrical rotating nozzle 11 which is a part of the dust removing apparatus of the cleaner type. FIG. 6A is a cross section of the rotating nozzle 11 in a direction orthogonal to a longitudinal direction of a compressed air concentrating pipe 14. And FIG. 6A illustrates that compressed air 15 is blown to dust 13 on a substrate 12. Moreover, FIG. 6B is a cross section in case of rotating the rotating nozzle 11 shown in FIG. 6A by the angle of 90 degrees. FIG. 6B illustrates that the dust 13 on the substrate 12 is sucked.
As shown in FIG. 6A and FIG. 6B, the dust removing apparatus of the cleaner type includes the rotating nozzle 11, which may rotate in the predetermined direction and be arranged close to the substrate 12. The dust removing apparatus blows the compressed air 15 from a compressed air jet outlet hole 16 which is set on the surface of the rotating nozzle 11, while rotating the rotating nozzle 11. The dust removing apparatus sucks the air at high pressure into a high-pressure inlet hole 17, while blowing the compressed air 15, and consequently sucks the dust 13 on to a surface of the substrate 12.
Thus, the dust removing apparatus of the cleaner type blows compressed air to a surface of a substrate and then sucks dust. Therefore, when the dust removing apparatus blows the compressed air to the substrate, contaminated particles such as oil mist included in the compressed air may adhere to the substrate. When the contaminated particles adhere to the substrate, the substrate may become a defective product. Accordingly, the dust removing apparatus of the cleaner type tends to produce a defective product.
On the other hand, a dust removing apparatus of a suction type removes dust through only sucking the dust without blowing compressed air to a substrate. Since the dust removing apparatus does not blow the compressed air to the substrate, the contaminated particles such as oil mist do not adhere to the substrate. However, since the dust removing apparatus removes the dust through only sucking the dust, the dust removing apparatus of the suction type is inferior to the dust removing apparatus of the cleaner type with respect to a performance of removing dust.
As shown in FIG. 7, for example, a dust removing apparatus of a suction type includes a table 19 which adsorbs a substrate 18 and a suction nozzle 20 which is arranged above the substrate 18. The dust removing apparatus of the suction type then sucks dust adhering to the substrate 18. The suction nozzle 20 has a rectangular shape whose thickness is less than width thereof. The suction nozzle 20 connects to a duct 21 at a center portion of a top surface of the suction nozzle 20. An end portion of the duct 21 connects to a suction unit (not shown). If the suction unit sucks air, the suction nozzle 20 which connects to the other end portion of the duct 21 sucks air into a bottom surface of the suction nozzle 20. The suction nozzle 20 sucks dust on the substrate 18 by sucking air.
The dust removing apparatus of the suction type slowly moves forward the table 19 in a predetermined direction to suck air into the suction nozzle 20 over a whole surface of the substrate 18. The dust removing apparatus sucks dust on the surface of the substrate 18 together with air, through sucking air into the suction nozzle 20 over the whole surface of the substrate 18.
A performance of the dust removing apparatus of the suction type with regard to removing dust is dependent on a moving speed of the table 19, a distance between the suction nozzle 20 and the substrate 18, and a sucking force of the suction unit connected to the suction nozzle 20. Therefore, in order to improve the performance of the dust removing apparatus of the suction type with regard to removing dust, it is most effective to slowly move the table 19 to suck air. However, if the table 19 slowly moves, processing efficiency decreases. In recent years, a substrate becomes large-sized in particular. Therefore, moving stroke has to be long in order to suck dust over the whole surface of the large-sized substrate. Accordingly, when the table 19 slowly moves at long stroke, it takes long processing time per one substrate for removing dust.
It may be possible to increase sucking force of the suction unit in order to improve the performance of the removing dust apparatus of the suction type with regard to removing dust. But, in order to increase the sucking force of the suction unit, it is required to improve performance of a motor of the suction unit. However, a power of an available motor is limited. Accordingly, improving the performance of the dust removing apparatus with regard to removing dust through improvement of the motor is limited.

SUMMARY OF THE INVENTION

The present invention was made to solve the foregoing and other exemplary problems, drawbacks, and disadvantages. A first exemplary feature of the present invention is to provide, a nozzle and a dust removing apparatus in which a processing time per one substrate for removing dust does not increases. A second exemplary feature of the present invention is to provide a nozzle and a dust removing apparatus which improve a performance of removing dust without improvement of a performance of a motor of a suction unit.
In an exemplary embodiment, a nozzle for sucking dust includes an opening part which is disposed at an end of the nozzle, and is sucking air to suck dust; and a turbulent air flow generating part which is disposed near the opening part to generates a turbulent air flow in the sucked air.
In other exemplary embodiment, a dust removing apparatus includes: a nozzle which sucks air to suck dust, and is generating a turbulent air flow in the sucked air; a rotatable table on which a substrate is disposed; and a rocking part which rocks the nozzle which is capable of approaching a surface of the substrate.
Other exemplary features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary features and advantages of the present invention will become apparent from the following detailed description when taken with the accompanying drawings in which:

FIG. 1 is a perspective view showing a dust removing apparatus according to an exemplary embodiment of the present invention;

FIG. 2 is a flowchart showing an example of an operation according to an exemplary embodiment of the present invention;

FIG. 3A is a side view showing an example of a suction nozzle according to an exemplary embodiment of the present invention;

FIG. 3B is a bottom view showing an example of a suction nozzle according to an exemplary embodiment of the present invention;

FIG. 4A shows an example of a part of a nozzle cover in a honeycombed shape having plural hexagonal holes;

FIG. 4B shows an example of a part of a nozzle cover in a honeycombed shape having plural triangular holes;

FIG. 4C shows an example of a part of a nozzle cover in a honeycombed shape having plural square holes;

FIG. 4D shows an example of a part of a nozzle cover in a honeycombed shape having plural circular holes;

FIG. 4E shows an example of a part of a nozzle cover in a honeycombed shape having plural elliptic holes;

FIG. 5A is an enlarged drawing showing an example of the nozzle cover in the honeycombed shape;

FIG. 5B shows an example of the state that a speed of air flow at a different position is different each other and consequently, a turbulent air flow generates;

FIG. 6A is a cross section of a rotating nozzle used in a dust removing apparatus of a cleaner type;

FIG. 6B is a cross section in case of rotating a rotating nozzle shown in FIG. 6A by the angle of 90 degrees; and

FIG. 7 shows a dust removing apparatus of a suction type.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will now be described in detail in accordance with the accompanying drawings.
FIG. 1 is a perspective view showing a dust removing apparatus according to an exemplary embodiment of the present invention. FIG. 1 shows a transparent suction nozzle 1 in order to correctly illustrate a whole structure of the dust removing apparatus. However the suction nozzle can be made by a non-transparent member.
The dust removing apparatus of the exemplary embodiment shown in FIG. 1 includes the suction nozzle 1, a nozzle cover (i.e. a turbulent air flow generating part) 2, a duct 3, a substrate adsorbing table 4, a table rotating unit 5, a nozzle rocking part 6 and a nozzle displacing part 7.
The suction nozzle 1 includes a rectangular shape whose thickness is less than width thereof. That is, a top surface and a bottom surface of the suction nozzle 1 are rectangular in shape. The suction nozzle 1 mounts the nozzle cover 2 under the bottom surface thereof. The suction nozzle 1 connects to the duct 3 at the center portion of the top surface thereof. The nozzle cover 2 is located under the bottom surface of the suction nozzle 1 to cover the bottom surface thereof. An end portion of the duct 3 connects to a suction unit (not illustrated). While the suction unit sucks air, the suction nozzle 1 which connects to the other end portion of the duct 3 sucks air through the nozzle cover 2. The substrate adsorbing table 4 is arranged so as to adsorb a substrate 8 on a surface thereof. The substrate 8 is a liquid crystal display panel substrate, a glass substrate, a semiconductor substrate or the like. Dust, dirt, fine particles, foreign substrates or the like adhere to a surface of the substrate 8 in a manufacturing process of a device including the substrate 8. The table rotating unit 5 rotates the substrate adsorbing table 4. The nozzle rocking parts 6 is located at both end portions of the top surface of the suction nozzle 1 respectively. If a set of the nozzle rocking parts 6 rocks the suction nozzle 1 in a longitudinal direction thereof, the suction nozzle 1 rocks in the direction thereof. The nozzle displacing part 7 may displace the suction nozzle 1 to place the suction nozzle 1 at a central portion above the substrate adsorbing table 4 or at a portion away therefrom for making the suction nozzle 1 evacuated from the substrate adsorbing table 4. A set of the nozzle displacing parts 7 connects to the set of nozzle rocking parts 6 respectively. The set of the nozzle displacing parts 7 moves in the back and fore direction (the direction vertical to the horizontal direction of the suction nozzle 1) of the suction nozzle 1. By moving the set of the nozzle displacing parts 7 in the back and fore direction of the suction nozzle 1, the set of nozzle rocking parts 6 which connects to the nozzle displacing parts 7 moves in the back and fore direction of the suction nozzle 1. As a result, the suction nozzle 1 which connects to the nozzle rocking part 6 moves in the back and fore direction of the suction nozzle 1. The suction nozzle 1 is arranged close to the substrate 8 on the substrate adsorbing table 4 to suck air. The suction nozzle 1 sucks dust on the substrate 8 through the nozzle cover 2 by sucking air.
An operation of the dust removing apparatus according to the exemplary embodiment of the present invention is described in detail with reference to FIG. 2, FIG. 3A, FIG. 3B, FIG. 4A, FIG. 4B, FIG. 4C, FIG. 4D and FIG. 4E, FIG. 5A and FIG. 5B.
FIG. 2 is a flowchart showing an example of operation according to the exemplary embodiment of the present invention. FIG. 3A is a side view of a suction nozzle of the exemplary embodiment of the present invention. The side view shows a side face which is approximately orthogonal to a longitudinal direction of the suction nozzle 1. FIG. 3B is a bottom view of the suction nozzle of the exemplary embodiment of the present invention. The nozzle cover 2 is mounted under the bottom of the suction nozzle 1. The duct 3 which connects to the suction unit is mounted on a top surface of the suction nozzle 1. An opening part 9 having a slit shape is formed on the bottom surface of the suction nozzle 1. The nozzle cover 2 is placed under the bottom surface of the suction nozzle 1 so that the opening part 9 thereof may be covered. The nozzle cover 2 is detachably fixed by nozzle cover fixing boards 10 which are arranged at both ends of the nozzle cover 2. If the suction unit sucks air, the opening part 9 sucks air through the nozzle cover 2.
In a step S21 of FIG. 2, the nozzle displacing part 7 moves the suction nozzle 1 to place the suction nozzle 1 at a position away from a region where substrates 8 are located. That is, the suction nozzle 1 is evacuated from a zone above the substrate adsorbing table 4. In a step S22 of FIG. 2, for example, a robot hand (not shown) discharges a substrate 8 from a previous process and charges the substrate 8 on a substrate adsorbing table 4. In a step S23 of FIG. 2, the substrate adsorbing table 4 adsorbs the substrate 8 to fix the substrate 8 thereon.
In a step S24 of FIG. 2, the nozzle displacing part 7 moves the suction nozzle 1 which is evacuated from the zone above the substrate adsorbing table 4 to a center portion of the zone thereabove. An end portion of the nozzle cover 2 is arranged close to the substrate 8 on the substrate adsorbing table 4, for example, at intervals of 1 mm. The interval may be changed appropriately to the most suitable value based on, for example, a specification of the dust removing apparatus, characteristics of the substrates 8, or a kind of dust.
In step S25 of FIG. 2, the suction unit starts to suck air. Then, the duct 3 which connects to the suction unit sucks air. And the opening part 9 which is set at an end portion of the suction nozzle 1 sucks air.
In step S26 of FIG. 2, while the opening part 9 sucks air, air is sucked through the nozzle cover 2.
As shown in FIG. 4A to FIG. 4E, the nozzle cover 2 includes a plurality of holes. The holes may be triangular, square or hexagonal in shape. Furthermore, the holes may be circular, elliptic or polygonal in shape. The nozzle cover 2 may include a plurality of hexagonal holes which are so-called honeycombed shape. A shape, like the honeycombed shape which may form a plane without clearance, is desirable.
When the opening part 9 having a slit shape arranged at the end portion of the suction nozzle 1 sucks air, the sucked air increases in flow speed thereof near the opening part 9, because the opening part 9 approaches the substrate 8 at the intervals of about 1 mm. When a sucking force of the suction unit is, for example, several Kilo Pascals (KPa), the flow speed of the sucked air becomes about several meters to 50 meters per second.
The nozzle cover 2 having a plurality of holes in the honeycombed shape generates a slow air flow and a fast air flow speed. In detail, the air flow becomes fast around a center region of each of the holes of the nozzle cover 2, and becomes slow near a boundary region between the holes. Accordingly, a turbulent air flow occurs near the opening part 9.
FIG. 5A is an enlarged view of the nozzle cover 2 in the honeycombed shape. FIG. 5B shows that the nozzle cover 2 in the honeycombed shape generates the slow and fast air flows to generate the turbulent air flow. In this example of the nozzle cover, a diameter of the hole of the nozzle cover 2 is, for example, about 2 mm, and an interval between the holes is, for example, about 0.5 mm to 1.5 mm. A thickness of the nozzle cover 2 is, for example, about 0.2 mm to 1 mm. The values may be changed appropriately to the most suitable values based on specifications of the dust removing apparatus, characteristics of the substrates 8 or a kind of dust, for example.
As indicated by a thin arrow in FIG. 5B, an air flow becomes slow at an edge region of the hole and at a boundary region therebetween. As indicated by a thick arrow in FIG. 5B, an air flow becomes faster around a center area of the hole than at the regions above described. The turbulent air flow occurs due to the slow air flow and the fast air flow. The turbulent air flow enhances a performance of removing dust on the substrate 8, because the turbulent air flow tends to strip the substrate 8 of dust. The opening part 9 sucks the air including the turbulent air flow, and consequently sucks the dust on the substrate 8 which is involved in the turbulent air flow.
In a step S27 of FIG. 2, the nozzle rocking part 6 rocks the suction nozzle 1. At the same time, the table circling unit 5 rotates the substrate adsorbing table 4 to rotate the substrate 8. The rotating speed may be constant or may be adjustable in a multi-speed manner. An operation speed of the nozzle rocking part 6 may be adjustable to be constant or to be variable, depending on a situation of removing dust.
Rocking the suction nozzle 1 and rotating the substrate 8 reinforce the turbulent air flow and a fast air flow which is generated near the end portion of the suction nozzle 1. The opening part 9 sucks the reinforced fast and turbulent air flow to efficiently suck dust adhering to the substrate 8.
In a step S28 of FIG. 2, the suction unit stops sucking air after a predetermined period of time elapses (for example, after completion of sucking dust over a whole surface of the substrate 8), and then, the opening part 9 stops sucking air. Moreover, the nozzle rocking part 6 stops the operation to stop rocking the suction nozzle 1. The table rotating unit 5 stops rotating the substrate adsorbing table 4 and stops rotating the substrate 8 thereon.
In a step S29 of FIG. 2, the nozzle displacing part 7 moves the suction nozzle 1 to place the suction nozzle 1 at a position away from a region where substrates 8 are located. As a result, the suction nozzle 1 is evacuated from the zone above the substrate adsorbing table 4.
In a step S30 of FIG. 2, for example, the robot hand (not illustrated) clutches the substrate 8 on the substrate adsorbing table 4 and discharges it therefrom.
As described above, according to the dust removing apparatus according to the exemplary embodiment of the present invention, when the opening part 9 sucks air, the turbulent air flow is generated in the sucked air by the nozzle cover 2 in the honeycombed shape. The turbulent air flow tends to strip the substrate of dust to readily suck the dust. Therefore, it is possible for the dust removing apparatus to improve the performance of removing dust without increasing a performance of the motor of the suction unit which sucks air. According to the dust removing apparatus of the exemplary embodiment, the substrate 8 on the substrate adsorbing table 4 is rotated by the table rotating unit 5, and furthermore, the suction nozzle 1 is rocked by the nozzle rocking part 6 when the suction nozzle 1 approaches a surface of the substrate 8. Accordingly, by rotating the substrate 8 and rocking the suction nozzle 1, the turbulent air flow is reinforced above the substrate 8, and consequently, the capability of suction of dust improves further. Moreover, according to the dust removing apparatus of the exemplary embodiment, the substrate adsorbing table 4 is rotated and the substrate 8 on the substrate adsorbing table 4 is rocked by the nozzle rocking part 6. Dust adhering to the substrate 8 is removed without moving the substrate adsorbing table 4. Thus, it does not take a long processing time per one substrate for removing dust, even if the substrate is large.
The previous description of exemplary embodiments is provided to enable a person skilled in the art to make and use the present invention. Moreover, various modifications to these exemplary embodiments will be readily apparent to those skilled in the art, and the generic principles and specific examples defined herein may be applied to other exemplary embodiments without the use of inventive faculty. Therefore, the present invention is not intended to be limited to the exemplary embodiments described herein but is to be accorded the widest scope as defined by the limitations of the claims and equivalents.
Further, it is noted that the inventor's intent is to retain all equivalents of the claimed invention even if the claims are amended during prosecution.
While this invention has been described in connection with certain preferred exemplary embodiments, it is to be understood that the subject matter encompassed by way of this invention is not to be limited to those specific exemplary embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternative, modification and equivalents as can be included within the spirit and scope of the following claims.
Further, it is the inventor's intention to retain all equivalents of the claimed invention even if the claims are amended during prosecution.

Claims

1. A nozzle for sucking dust, comprising:

an opening part which is disposed at an end of the nozzle, the opening part sucking air to suck dust; and

a turbulent air flow generating part which is disposed near the opening part to generates a turbulent air flow in the sucked air.

2. The nozzle according to claim 1, wherein the turbulent air flow generating part detachably covers the opening part.

3. The nozzle according to claim 2, further comprising a nozzle body which attaches the turbulent air flow generating part, wherein an end of the turbulent air flow generating part is detachably fixed on the nozzle body by a fixing member.

4. The nozzle according to claim 1, wherein the turbulent air flow generating part includes a plurality of holes.

5. The nozzle according to claim 4, wherein a shape formed in a plurality of holes includes a honeycombed shape.

6. The nozzle according to claim 4, wherein the hole is triangular, square or hexagonal in shape.

7. The nozzle according to claim 4, wherein the hole is circular, elliptic or polygonal in shape.

8. The nozzle according to claim 1, wherein the opening part includes a slit.

9. The nozzle according to claim 1, wherein the opening part is capable of approaching the dust to suck.

10. A dust removing apparatus, comprising:

a nozzle which sucks air to suck dust, the nozzle generating a turbulent air flow in the sucked air;

a rotatable table on which a substrate is disposed; and

a rocking part which rocks the nozzle which is capable of approaching a surface of the substrate.

11. The dust removing apparatus according to claim 10, wherein

the nozzle including:

an opening part which is disposed at an end of the nozzle; and

a turbulent air flow generating part which is disposed near the opening part to generates the turbulent air flow in the sucked air.

12. The dust removing apparatus according to claim 11, wherein the turbulent air flow generating part detachably covers the opening part.

13. The dust removing apparatus according to claim 12, wherein the nozzle includes a nozzle body which attaches the turbulent air flow generating part, and wherein an end of the turbulent air flow generating part is detachably fixed on the nozzle body by a fixing member.

14. The dust removing apparatus according to claim 11, wherein the turbulent air flow generating part includes a plurality of holes.

15. The dust removing apparatus according to claim 14, wherein a shape formed in a plurality of holes includes a honeycombed shape.

16. The dust removing apparatus according to claim 14, wherein the hole is triangular, square or hexagonal in shape.

17. The dust removing apparatus according to claim 14, wherein the hole is circular, elliptic and polygonal in shape.

18. The dust removing apparatus according to claim 11, wherein the opening part includes a slit.

19. The dust removing apparatus according to claim 10, further comprising:

a nozzle displacing part which is capable of displacing the nozzle to place the nozzle above the rotatable table and in a region away from the rotatable table.