JP2010172868A - Apparatus and method for dropping liquid material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for dropping a liquid material, wherein an opening on the upper part of a wind prevention box is designed to have a size that eliminates downflow effects and is convenient for vessel exchange. <P>SOLUTION: In the apparatus for dropping liquid crystal 10 for discharging the liquid crystal L from a nozzle 23 to drop it on a substrate, an electronic balance 41 for measuring the mass of the liquid crystal L by placing a measurement vessel 42 thereon for receiving liquid crystal L discharged from the nozzle 23 is provided within a wind prevention box 60 and an opening and closing apparatus 70 capable of forming an opening part 70A is provided on the upper part of the wind prevention box 60 that functions as a dropping pathway through which liquid crystal L discharged from the nozzle 23 reaches the measurement vessel 42 on the electronic balance 41, so as to make it possible to vary the size of the opening part 70A of the opening and closing apparatus 70. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and method for dropping a liquid substance such as liquid crystal.

  In a manufacturing process of a liquid crystal display device or the like, there is a film forming process for forming a circuit pattern on a substrate such as glass. In this film formation process, a functional thin film such as an alignment film or a resist is formed on the substrate.

  When a functional thin film is formed on a substrate, a liquid material dropping device that discharges and drops a liquid material forming the functional thin film from a nozzle is used. In this liquid substance dropping device, it is necessary to control the amount of liquid substance dropped from the nozzle with high accuracy. As described in Patent Document 1, a container for receiving the liquid substance discharged from the nozzle is placed on the liquid substance dropping apparatus. An electronic balance for measuring mass is provided. At a predetermined timing, for example, every time when dropping of the liquid material onto a plurality of substrates is completed, the electronic material is used to receive the liquid material discharged from the nozzle into a container on the electronic balance and measure its mass. .

Japanese Unexamined Patent Publication No. 2007-7611

  In the liquid substance dropping device, even when the amount of liquid substance dripping from the nozzle is made minute, in order to improve the measurement accuracy of the dripping amount by the electronic balance, the electronic balance is installed in the windshield box, and the liquid substance dropping device is It is conceivable to prevent the downflow of the clean room used (airflow from the ceiling side to the floor side of the clean room in order to prevent dust from rising in the clean room) from reaching the container on the electronic balance. This is to prevent the downflow from hitting the liquid surface of the liquid substance already contained in the container and the fluctuation occurring on the liquid surface from impairing the measurement accuracy of the electronic balance.

  Therefore, the size of the opening at the top of the draft shield box, which is a dripping path for the liquid material discharged from the nozzle to the container on the electronic balance, is as much as possible in order to take into account the effects of the downflow described above. It needs to be small.

  However, in the liquid substance dropping device, an electronic balance is used for each predetermined timing at which the liquid substance discharged from the nozzle is dropped onto the substrate, and the liquid substance discharged from the nozzle is received in a container on the electronic balance. Each time the liquid level in the container reaches a certain level, it is necessary to replace the container with an empty container. Therefore, in order to replace the container, it is necessary to make the size of the opening at the top of the windshield box into and out of the container as large as possible. That is, it is difficult to set the opening at the top of the windshield box to a size that eliminates the effect of downflow and is convenient for container replacement.

  An object of the present invention is to set an opening at the top of a windshield box to a size that eliminates the influence of downflow and is convenient for replacement of a container in a liquid substance dropping apparatus and method.

  According to a first aspect of the present invention, there is provided a liquid substance dropping device that discharges a liquid substance from a nozzle and drops it onto a substrate. An electronic balance for measuring a mass of the liquid substance by placing a container for receiving the liquid substance discharged from the nozzle. An opening / closing device that can be formed in the upper portion of the windshield box, which is a dripping path for the liquid substance discharged from the nozzle to reach the container on the electronic balance, and is installed in the windshield box. The size can be changed.

  According to a second aspect of the present invention, in the first aspect of the invention, the opening / closing device further includes a plurality of shutter blades that form the opening, a fixed frame that swingably supports the plurality of shutter blades, and the fixed frame. And a movable frame that engages with the shutter blades so that the size of the opening surrounded by the shutter blades can be changed by adjusting the rotational position of the movable frame. It is a thing.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the opening / closing device sets the size of the opening when the liquid material discharged from the nozzle is dropped onto the container on the electronic balance. The container on the balance is made smaller than when the container is replaced.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the opening / closing device discharges from the nozzle the size of the opening when the liquid material discharged from the nozzle is dropped onto the container on the electronic balance. The minimum size required for the passage of the liquid material is made.

  The invention of claim 5 is a liquid substance dropping method using the liquid substance dropping device according to any one of claims 1 to 4, wherein the liquid substance discharged from the nozzle is dropped into a container on an electronic balance. The size of the opening of the switchgear is made smaller than the size of the opening of the switchgear when the container on the electronic balance is replaced.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the size of the opening of the opening / closing device when the liquid substance discharged from the nozzle is dropped onto the container on the electronic balance is discharged from the nozzle. The minimum size required for the passage of the liquid material.

  According to the present invention, when the liquid material discharged from the nozzle is dropped onto the container on the electronic balance, the size of the opening of the opening / closing device can be reduced, and the clean room provided with the liquid material dropping device can be downed. It is possible to prevent the flow from reaching the container on the electronic balance as much as possible. It is possible to prevent the downflow from hitting the liquid level of the liquid substance already contained in the container and the fluctuation occurring on the liquid level from impairing the measurement accuracy of the electronic balance.

  In addition, when replacing the container on the electronic balance, the size of the opening of the switchgear can be increased, and whenever the liquid level of the liquid substance dripped into the container from the nozzle reaches a certain level, The container can be easily replaced with an empty container.

  In the normal operation in which the electronic balance is used or the container is not replaced, the opening of the opening / closing device is closed to completely prevent the downflow of the clean room from reaching the container on the electronic balance.

FIG. 1 is a schematic view showing a liquid crystal dropping device. FIG. 2 is a cross-sectional view showing a supply device of the liquid crystal dropping device. FIG. 3 is a sectional view showing an opening / closing device of the liquid crystal dropping device. FIG. 4 is a plan view of FIG. FIG. 5 is a perspective view showing a main part of the switchgear. FIG. 6 is a schematic diagram showing changes in the size of the opening of the switchgear.

  A liquid crystal dropping apparatus 10 shown in FIG. 1 drops a substrate transport stage 11 on which a rectangular lower substrate 1 is mounted, and a liquid crystal L as a liquid substance by an amount (mass) set at a predetermined dropping position on the lower substrate 1. And a liquid crystal supply device 20 that supplies the set total amount (total mass) of the liquid crystal L onto the substrate 1. The lower substrate 1 is coated with a sealing agent 4 for enclosing the liquid crystal L along the outer peripheral edge thereof. After the liquid crystal L is dropped on the lower substrate 1, an upper substrate (not shown) is bonded onto the lower substrate 1 to manufacture a liquid crystal display panel. The lower substrate 1 and the upper substrate are made of glass substrates.

  The substrate transfer stage 11 includes a moving device 12 having an X-axis drive unit, a Y-axis drive unit, and a θ-axis drive unit, and moves the lower substrate 1 in each of the X direction and the Y direction and around the θ axis. Can rotate. Each drive part of the moving apparatus 12 can be comprised with a servomotor.

The liquid crystal supply device 20 includes a container 40 and a moving device 50.
The container 40 stores the liquid crystal L.

  The moving device 50 includes an X-axis drive unit, a Y-axis drive unit, and a Z-axis drive unit, and moves the liquid crystal supply device 20 in each of the X direction, the Y direction, and the Z direction. Each drive unit of the moving device 50 can be constituted by a servo motor. The moving device 12 and / or the moving device 50 moves the liquid crystal supply device 20 relative to the lower substrate 1 on the substrate transfer stage 11.

  The liquid crystal supply device 20 includes a take-out port 21 for taking out the liquid crystal L from the container 40, a storage chamber 22 for temporarily storing the taken-out liquid crystal L, and a nozzle 23 for discharging the liquid crystal L taken out and stored.

  Specifically, as shown in FIG. 2, the liquid crystal supply device 20 includes a fixed portion 24 and a rotating portion 27 provided on a rotating shaft 26 driven by a servo motor 25. One take-out port 21 and one nozzle 23 are provided on the same radius centered on the axis of the rotary shaft 26 and at opposite positions sandwiching the rotary shaft 26, and two storage chambers 22 are provided in the rotating portion 27. When one storage chamber 22 faces the take-out port 21, the other storage chamber 22 is provided at a position facing the nozzle 23. The rotating portion 27 is in fluid-tight sliding contact with the fixed portion 24, and the two storage chambers 22 pass through the take-out port 21 and the nozzle 23 in order by the rotation of the rotating portion 27.

  The liquid crystal supply device 20 includes a plurality of guide holes provided in a rotating plate 29 in which a cam 28 facing the rotating portion 27 is fixedly disposed around the rotating shaft 26 and fixed between the rotating portion 27 and the cam 28 on the rotating shaft 26. 32, the same number of plungers 30 as the storage chamber 22 are held so as to be movable up and down, and the lower end portion of the plunger 30 is fitted into the storage chamber 22 so that it can reciprocate inside the storage chamber 22, and the upper end portion of the plunger 30 ( The cam follower 30 </ b> A) is brought into contact with the cam surface of the cam 28 by a spring 31. The spring 31 is interposed between a flange 30 </ b> B provided at an intermediate portion of the plunger 30 and the rotary plate 29.

  The liquid crystal supply device 20 performs the pumping action as follows by the rotation of the rotating unit 27 by the servo motor 25.

(a) Extraction action When the storage chamber 22 of the rotating portion 27 passes through the extraction port 21 of the fixed portion 24, the plunger 30 moves inside the storage chamber 22 from the lower limit to the upper limit. When the plunger 30 moves from the lower limit to the upper limit, an amount (mass) of the liquid crystal L corresponding to the amount of movement is sucked from the container 40 via the take-out port 21 and taken out. Therefore, the amount (mass) of the liquid crystal L taken out into the storage chamber 22 is set by adjusting the amount of movement of the plunger 30 from the lower limit to the upper limit.

(b) Discharge action When the stock room 22 of the rotating part 27 passes through the nozzle 23 of the fixed part 24, the plunger 30 moves from the upper limit to the lower limit in the stock room 22 by an operation opposite to the take-out action. The liquid crystal L stored in (1) is discharged through the nozzle 23 and dropped onto the lower substrate 1 as one drop (constant mass) of liquid crystal L.

  The liquid crystal dropping device 10 has an electronic balance 41 in order to manage the dropping amount (mass) of one drop of the liquid crystal L from the nozzle 23 of the liquid crystal supply device 20 with high accuracy. The electronic balance 41 is provided on an L-shaped bracket 11 </ b> A fixed to the left side surface of the substrate transfer stage 11, and a weighing container 42 for receiving the liquid crystal L discharged from the nozzle 23 is placed on the electronic balance 41. Measure. Each time the dropping of the liquid crystal L onto the plurality of substrates 1 is completed at a predetermined timing, for example, the moving device 12 and / or the moving device 50 causes the nozzle 23 of the liquid crystal supply device 20 to be placed on the weighing container 42 on the electronic balance 41. One drop of liquid crystal L discharged from the nozzle 23 is received in the measuring container 42. The electronic balance 41 is connected to the control device 36, and the measurement value obtained as a result of measurement by the electronic balance 41 is taken into the control device 36. The current change amount of the measurement value of the electronic balance 41 is the mass of one drop of the liquid crystal L this time. As measured. The measuring container 42 is replaced with an empty container 42 every time the liquid level of the liquid crystal L repeatedly received in the container 42 reaches a certain level. Further, the liquid crystal L to be discharged into the measuring container 42 for weighing is not limited to one drop and may be a plurality of drops. In this case, the mass value of one drop of liquid crystal may be obtained by dividing the measured value by the number of drops of liquid crystal L discharged.

  In order to improve the measurement accuracy of the dropping amount by the electronic balance 41 even when the dropping amount of the liquid crystal L from the nozzle 23 of the liquid crystal supply device 20 is made small, the liquid crystal dropping device 10 places the electronic balance 41 in the windshield box 60. The down flow of the clean room in which the liquid crystal dropping device 10 is used is prevented from reaching the measuring container 42 on the electronic balance 41.

  As shown in FIG. 3, the windshield box 60 includes a rectangular tubular side wall portion 61 fixed on the bracket 11 </ b> A. An opening / closing device 70 is provided on the windshield box 60, which is a dropping path for the liquid crystal L discharged from the nozzle 23 to reach the measuring container 42 on the electronic balance 41. The opening / closing device 70 is capable of forming an opening 70 </ b> A in the upper part of the windshield box 60 by a plurality of shutter blades 71, and enables the size of the opening 70 </ b> A formed by the plurality of shutter blades 71 to be changed.

  As shown in FIGS. 4 and 5, the opening / closing device 70 has a fixed frame 72 fixed to the upper portion of the side wall portion 61, and a movable frame 73 that is rotatably fitted to and attached to the fixed frame 72. The fixed frame 72 supports a plurality of shutter blades 71 that are partially overlapped in the circumferential direction and swingably supported, and the movable frame 73 engages with the shutter blades 71 to adjust the rotational position of the movable frame 73. As a result, the shutter blades 71 change the size of the opening 70 </ b> A surrounded by the circular frame holes 72 </ b> A and 73 </ b> A of the fixed frame 72 and the movable frame 73. That is, the shutter blades 71A to 71F (only one is shown in FIGS. 4 and 5) made of a plurality (six in this embodiment) of thin steel plates have a fixing pin 74 projecting at one end on the back side, and the other on the front side. A movable pin 75 projects from the end. In the shutter blades 71A to 71F, the fixing pins 74 are pivotally supported by six support holes 74A provided on the upper surface of the fixed frame 72 at equal intervals on the same circumference. It is supported as a center so that it can swing. The shutter blades 71 </ b> A to 71 </ b> F have these movable pins 75 formed in six radial grooves 75 </ b> A provided at equal intervals on the lower surface of the movable frame 73 arranged coaxially with the virtual circle drawn by the six support holes 74 </ b> A. Engage.

  The opening / closing device 70 fixes the motor 76 to the fixed frame 72 and meshes a pinion 77 provided on the output shaft of the motor 76 with an arc-shaped rack 78 provided on a part of the outer periphery of the movable frame 73. The motor 76 is driven and controlled by the control device 36 in accordance with the operation status of the liquid crystal dropping device 10. When the movable frame 73 and the rack 78 are rotated clockwise by driving the motor 76, the shutter blades 71 </ b> A to 71 </ b> F are radially out of the fixed frame 72 and the frame holes 72 </ b> A and 73 </ b> A of the movable frame 73 around the fixed pin 74. And the diameter of the opening 70A is increased. When one end 78A of the rack 78 abuts against one stopper surface of the fixed frame 72, the opening 70A has a maximum diameter (FIG. 6A). When the movable frame 73 and the rack 78 are rotated counterclockwise by driving the motor 76, the shutter blades 71 </ b> A to 71 </ b> F are arranged around the fixed pin 74 in the radial direction of the frame holes 72 </ b> A and 73 </ b> A of the movable frame 73. It swings inward to reduce the size of the opening 70A. When the other end 78B of the rack 78 abuts against the other stopper surface of the fixed frame 72, the opening 70A is completely closed (FIG. 6C).

  Therefore, the control device 36 controls the liquid crystal L discharged from the nozzle 23 on the electronic balance 41 so that the liquid crystal dropping device 10 manages the dropping amount of the liquid crystal L from the nozzle 23 of the liquid crystal supply device 20. When the liquid is dropped, the motor 76 of the opening / closing device 70 is driven so that the size of the opening 70A is as small as necessary for passing the liquid crystal L (minimum necessary size) (FIG. 6B). Here, the small diameter necessary for the passage of the liquid crystal L may be determined, for example, by taking into account the variation in the ejection direction of the liquid crystal L in addition to the diameter of the droplet of the liquid crystal L to be dropped. The size may be about double. On the other hand, when the measuring container 42 on the electronic balance 41 is replaced, the control device 36 drives the motor 76 of the opening / closing device 70 so that the size of the opening 70A becomes the maximum diameter (FIG. 6A). Here, the size of the opening 70A is set to the maximum diameter in consideration of the convenience of replacement of the measuring container 42. However, if the measuring container 42 can be replaced, it is not necessarily limited to the maximum diameter. There is no. During the normal operation of the liquid crystal dropping device 10, that is, while the liquid crystal L is being dropped on the substrate 1, the opening 70A of the opening / closing device 70 is closed (FIG. 6C).

Therefore, according to the present embodiment, the following operational effects can be obtained.
(a) The opening / closing device 70 provided on the top of the draft shield box 60 that houses the electronic balance 41 and the weighing container 42 allows the size of the opening 70A formed by the shutter blades 71 (71A to 71F) to be changed. .

  Therefore, when the liquid crystal L discharged from the nozzle 23 is dropped onto the measuring container 42 on the electronic balance 41, the size of the opening 70A of the opening / closing device 70 can be reduced, and the liquid crystal dropping device 10 is provided. It is possible to prevent the downflow of the clean room from reaching the measuring container 42 on the electronic balance 41 as much as possible. It is possible to prevent the downflow from hitting the liquid level of the liquid crystal L already accommodated in the measuring container 42 and the fluctuation occurring on the liquid level from impairing the measurement accuracy of the electronic balance 41.

  Further, when the measuring container 42 on the electronic balance 41 is replaced, the size of the opening 70A of the opening / closing device 70 can be increased, and the liquid crystal L dropped from the nozzle 23 into the measuring container 42. Each time the surface reaches a certain level, the weighing container 42 can be easily replaced with an empty weighing container 42.

  During normal operation in which the electronic balance 41 is not used or the measuring container 42 is not replaced, the opening 70A of the opening / closing device 70 is closed, and the down flow of the clean room reaches the measuring container 42 on the electronic balance 41 completely. Can be prevented. Alternatively, after the liquid crystal L has been dropped into the measuring container 42, the opening 70A may be closed, and the dropping amount may be measured by the electronic balance 41 with the opening 70A closed. In this case, since the downflow of the clean room is completely blocked when measuring the dripping amount with the electronic balance 41, the measurement with the electronic balance 41 can be performed with higher accuracy.

  (b) The opening / closing device 70 supports a plurality of shutter blades 71 (71A to 71F) in a swingable manner, and the shutter blades 71 (71A to 71A) are rotatably attached to the fixed frame 72. 71F) and a movable frame 73 that engages, and by adjusting the rotational position of the movable frame 73, the size of the opening 70A that is surrounded by the shutter blades 71 (71A to 71F) can be changed. The size of the opening 70A can be changed stably.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention. For example, although an example of an opening / closing device using shutter blades as an opening / closing device has been described, other opening / closing devices capable of changing the size of the opening may be used. That is, a sliding door or the like that forms an opening of a size that allows the weighing container 42 to be taken in and out, and an opening of a minimum size that is necessary for the passage of the liquid crystal L discharged from the nozzle 23 to the door. An opening / closing device having a structure in which a sliding door or the like is provided may be used.

  In the liquid substance dropping apparatus and method according to the present invention, the opening at the top of the windshield box can be set to a size that eliminates the influence of downflow and is convenient for replacement of the container.

1 Substrate 10 Liquid crystal dropping device (liquid substance dropping device)
23 Nozzle 41 Electronic Balance 42 Weighing Container 60 Windshield Box 70 Opening / Closing Device 70A Opening 71, 71A to 71F Shutter Blade 72 Fixed Frame 73 Movable Frame

Claims (6)

In a liquid material dropping device for discharging a liquid material from a nozzle and dropping it on a substrate,
An electronic balance that mounts a container for receiving the liquid substance discharged from the nozzle and measures the mass of the liquid substance is installed in the windshield box,
An opening / closing device capable of forming an opening at the upper part of the windshield box, which is a dropping path for the liquid material discharged from the nozzle to reach the container on the electronic balance,
A liquid substance dropping device, wherein an opening / closing device makes it possible to change the size of the opening. The switchgear is
A plurality of shutter blades forming the opening, a fixed frame that swingably supports the plurality of shutter blades, and a movable frame that is pivotally attached to the fixed frame and engages with the shutter blades. The liquid substance dropping device according to claim 1, wherein the liquid substance dropping device is configured to change a size of an opening surrounded by the shutter blades by adjusting a rotation position of the movable frame.   The opening / closing device is characterized in that the size of the opening when the liquid material discharged from the nozzle is dropped onto the container on the electronic balance is smaller than when the container on the electronic balance is replaced. The liquid substance dripping device according to claim 1 or 2.   In the opening / closing device, the size of the opening when the liquid material discharged from the nozzle is dropped onto the container on the electronic balance is set to a minimum size necessary for the passage of the liquid material discharged from the nozzle. The liquid substance dropping device according to claim 3, wherein: A liquid substance dropping method using the liquid substance dropping apparatus according to claim 1,
The size of the opening of the opening / closing device when the liquid substance discharged from the nozzle is dropped onto the container on the electronic balance is smaller than the size of the opening of the opening / closing device when replacing the container on the electronic balance. Liquid substance dripping method.   The size of the opening of the opening / closing device when the liquid material discharged from the nozzle is dropped onto the container on the electronic balance is set to a minimum size necessary for the passage of the liquid material discharged from the nozzle. The liquid substance dripping method according to claim 5, wherein the liquid substance is dripped.

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