JP4682576B2 - Liquid crystal dropping device - Google Patents

Description

  The present invention relates to an apparatus for assembling a liquid crystal panel, and more particularly to a liquid crystal dropping apparatus that drops a desired amount of a liquid crystal agent at a desired position on a substrate.

  To manufacture a liquid crystal display panel, draw a pattern in which a sealing agent is closed on one of two glass substrates with transparent electrodes and thin film transistor arrays, and drop the liquid crystal agent inside the pattern. There is a method proposed in Patent Document 1 or the like in which the other substrate is placed on one substrate and the upper and lower substrates are brought close together in a vacuum.

  As a dropping method of the liquid crystal agent, there is a method proposed in Patent Document 2. The liquid crystal agent is stored in, for example, a tank type as in Patent Document 2 or a liquid crystal bottle.

Japanese Patent Laid-Open No. 62-165622

Japanese Patent Laying-Open No. 2003-164783

  Before attaching the liquid crystal agent to the liquid crystal supply device, expose the liquid crystal agent to a vacuum environment, and perform air venting treatment (hereinafter referred to as defoaming treatment) that dissolves in the liquid crystal agent during the purification, transportation, and storage of the liquid crystal agent. After that, it is used for production.

  When the liquid crystal agent supplied to the substrate is sealed in a vacuum, the liquid crystal agent will be exposed to a vacuum environment. At this time, if there is a lot of air dissolved in the liquid crystal agent, the counter substrate should be removed before degassing. Since the liquid crystal agent is sealed again, even the air is sealed in the substrate, and this is a factor in the display unevenness of the liquid crystal panel, which reduces productivity.

  Further, from the aspect of the supply accuracy of the liquid crystal agent, the tank type syringe disclosed in Patent Document 2 acts to increase the progress of dissolution of air because the inside of the tank is pressurized to adjust the opening time of the needle. .

  Also, in the microsyringe type (for example, TecanSystems, Inc. XL3000, etc.), if there is dissolved air, bubbles are generated when the liquid crystal material is sucked into the microsyringe under negative pressure, and the dropping accuracy becomes unstable. If the filling speed is slowed so as not to occur, productivity will be reduced.

  In order to reduce the area occupied by the device from the surface of the liquid crystal supply device, a configuration may be adopted in which liquid crystal is supplied to the substrate while moving the liquid crystal supply device in a direction parallel to the main surface of the substrate. In this case, since the production is performed while shaking the bottle containing the liquid crystal, it acts in the direction of increasing the progress of dissolution of air.

  In addition, when the liquid crystal agent is allowed to stand naturally, air is dissolved again in the liquid crystal agent. This process is a phenomenon that proceeds during production in the liquid crystal supply device.

  Therefore, an object of the present invention is to suppress the dissolution of air during liquid crystal as much as possible when supplying the liquid crystal agent from the tank to the microsyringe in order to accurately measure and supply the amount of liquid crystal agent to be supplied. An object of the present invention is to provide an apparatus that does not generate bubbles in a microsyringe that determines the amount.

In order to achieve the above object, the present invention includes a positive pressure source that changes the pressure inside the tank from a vacuum atmosphere to atmospheric pressure or a positive pressure, and a negative pressure source that changes the pressure inside the tank to a vacuum atmosphere . When the required amount of liquid crystal agent that has been defoamed is metered into the microsyringe, the positive pressure source is connected to the liquid crystal tank, and the required amount of the liquid crystal agent filled in the microsyringe is added to the microsyringe. in the step of dropping onto the substrate by supplying the nozzle, and a structure in which a solenoid valve for connecting the negative pressure source to the liquid crystal reservoir. Accordingly, it is possible to provide a liquid crystal dropping device that reduces the amount of air dissolved in the paste during production as much as possible and smoothly fills the liquid crystal agent without introducing bubbles during negative pressure suction.

  According to the present invention, the productivity of the liquid crystal panel can be improved by supplying the liquid crystal agent dropwise to the substrate accurately and stably without mixing bubbles, and suppressing the air from entering the liquid crystal agent in the liquid crystal tank. It becomes possible to improve.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a liquid crystal dropping device according to the present invention. In FIG. 1, Y axis moving mechanism support frames 2 a and 2 b for moving a liquid crystal dispenser 9 including a tank 107 and nozzles in the Y axis direction are provided on the frame 1. Y-axis moving mechanisms 4a and 4b are provided on the Y-axis moving mechanism support bases 2a and 2b in parallel with the Y-axis direction, and the coating head is moved on the Y-axis moving mechanisms 4a and 4b in the X-axis direction. An X moving mechanism shaft support frame 3 is provided. Further, a θ-axis moving table 6 is provided on the lower base 1 of the X-axis moving mechanism support rack 3, and a substrate holding mechanism 5 for holding the substrate 7 is provided on the θ-axis moving table 6. It is.

  The Y-axis moving mechanisms 4a and 4b are composed of a linear servo motor and a guide part (linear rail), and the linear rail is provided on the Y-axis moving mechanism support base 2a and 2b side with the X-axis movement mechanism support base 3 side linear servo motor. . That is, the X moving mechanism shaft support base 3 is moved in the Y axis direction. The X-axis moving mechanism 3a is composed of a linear servo motor and a guide part, and has a configuration in which a linear rail is provided on the X moving mechanism axis support base 3 side and a linear servo motor is provided on the liquid crystal dispenser support bracket 8 side. Thus, the liquid crystal dispenser 9 mounted on the dispenser support bracket 8 is configured to move in the X-axis direction.

  On the dispenser support bracket 8 side, a lens barrel having a light source capable of illumination and an image recognition camera 15 are attached. The image recognition camera is provided to face the substrate 7 for observing the alignment mark on the substrate 7 and recognizing the shape of the paste.

  Further, inside the gantry 1 are a main controller 17 that controls linear motors 3m, 4am, and 4bm that drive the XY-axis moving mechanism and a servomotor 6m that drives the θ-axis moving table, and a dispenser controller 18. And are provided. The main controller 17 and the dispenser controller 18 are connected by a signal cable 21. The dispenser control unit 18 controls a Z-axis motor 110 that drives a piston 102 of a microsyringe, which will be described later, an R-axis motor 103M that drives a flow path switching valve 103, an electromagnetic valve 121 for regulating pressure in the tank 107, and the like.

  A monitor 19, a keyboard 20, and a hard disk 22 that is an external storage device are connected to the main control unit 17. Data for various processes in the main control unit 17 is input from the keyboard 20, and an image captured by the image recognition camera 15 and a processing state in the main control unit 17 are displayed on the monitor 19. Data input from the keyboard 20 is stored and stored in the hard disk 22 which is an external storage device.

  Next, the structure of the liquid crystal dispenser 9 is shown in FIG.

  The liquid crystal dispenser 9 includes a micro syringe part M1, a flow path switching part M2, a suction part M3, a discharge part M4, a drive part M5, and a dispenser control part 18.

  The microsyringe part M1 is composed of a glass microsyringe 101 and a piston 102 that moves in the direction of the arrow by a driving part.

  The flow path switching unit M2 includes a switching valve 103 that performs flow path switching by rotating the flow path switching port 104 by an R-axis motor 103M (not shown), and the joint 105. is doing. The switching timing of the switching valve 103 is controlled by the dispenser control unit 18 so that a motor (not shown) does not overlap with the movement of the piston 102.

  In this figure, the direction of the flow path switching port 104 is set so as to connect the flow paths AB, and this position is referred to as a suction port position. A position where the direction of the flow path switching port 104 is rotated to connect B-C is referred to as a discharge port position.

  The suction part M3 includes a tube 106 and a liquid crystal tank 107 filled with the liquid crystal agent 120 that has already been defoamed. One end of each of the tube 106 and the tube 128 is inserted into the liquid crystal tank 107, and a lid 125 that can be sealed so as not to leak air is attached. One end side of the tube 106 is disposed in the liquid crystal tank 107 so that the end thereof is located near the bottom surface of the liquid crystal tank 107, and the other end side is connected to the flow path A through the joint 105. One end side of the tube 128 is disposed near the upper cover 125 of the liquid crystal tank 107, and the other end side is connected to the electromagnetic valve 121 via a filter 122 for preventing foreign matters from entering the liquid crystal agent. Yes. The electromagnetic valve 121 is connected to a positive pressure source and a negative pressure source for adjusting the atmosphere in the tank to atmospheric pressure, a positive pressure atmosphere, or a negative pressure atmosphere.

  The discharge unit M4 side includes a tube 108 and a nozzle 109 attached to the tip of the tube 108. The other end of the tube 108 is connected to the flow path C through the joint 105. The nozzle 109 is attached so as to be positioned at the lowermost portion of the dispenser 9 by a bracket (not shown), and is configured to be adjusted to a height of about 2 mm from the substrate by a height adjusting mechanism (not shown).

  The drive unit M5 rotates the Z-axis motor 110 based on a drive signal from the main control unit 18 to precisely position and drive the piston 102, and via a screw 111 connected to the axis of the Z-axis motor 110. The nut 112 is moved along the guide mechanism 114. In this figure, the piston 102 is moved up and down to drive the piston 102 up and down via the connecting portion 113.

  Next, the control method in a present Example is demonstrated.

FIG. 3 is a block diagram showing the configuration of the main control unit 17 in FIG. In the figure, the main control unit 17 has a configuration in which a microcomputer 17a connects a motor controller 17b, an external interface 17d, and an image recognition unit 17e via a data communication bus 17c. An X-axis linear motor driver 17f, Y-axis linear motor drivers 17g and 17h, and a θ-axis motor driver 17i are connected to the motor controller 17b.

  In the drawing, various external devices are connected to the main control unit 17 to control each device. For example, motors 3m, 4am, 4bm, and 6m for driving the respective axes of X, Y, and θ and encoders provided for the respective motors are connected to drivers 17f to 17i of the respective axes, and the image recognition camera 15 The obtained video signal is connected to the image processing unit 17e, and the external interface 17d is connected to the dispenser control unit 18, the monitor 19, the keyboard 20, the hard disk 22, and the like. Although not shown in the microcomputer 17a, a ROM that stores a processing program for performing a drawing process, which will be described later, a processing program in the main processing unit, input data from the external interface 17d and the motor controller 17b. A RAM for storing data, an input / output unit for exchanging data with the external interface 17d and the motor controller 17b, and the like are provided.

  In the figure, a network cable 25 is connected to the external interface 17d, and a management computer for managing the operation status of a production factory where the present apparatus (not shown) is used is connected via the network cable 25. It is connected to a network 26 to which other devices are connected. By adopting such a configuration, management such as automatic switching control of the operating status and operating conditions of the apparatus and control of loading / unloading of the substrate is performed.

  Each of the motors 3m, 4am, 4bm, and 6m has a built-in linear scale for detecting the position and an encoder for detecting the rotation amount as described above. 17i, and position control is performed based on the result.

FIG. 4 is a block diagram showing the configuration of the dispenser control unit 18 in FIG. Inside the dispenser controller 18, a microcomputer 18a is connected to a motor controller 18b and an external interface 18d via a data communication bus 18c. Furthermore, a Z-axis motor driver 18e that controls the piston 102 in the microsyringe 101 up and down and an R-axis motor driver 18f that drives the liquid crystal flow path switching valve 103 are connected to the motor controller 18b.

  Although not shown in the microcomputer 18a, a ROM that stores a processing program for performing piston position control when supplying a main calculation unit and liquid crystal, a processing result in the main calculation unit, an external interface 18d, and a motor controller 18b It includes a RAM that stores input data, an input / output unit that exchanges data with the external interface 18d and the motor controller 18b, and the like.

  The external interface 18d is connected to the solenoid valve 121, a positive pressure regulator 123 connected to the positive pressure source 130 to adjust the pressure applied to the liquid crystal tank 107, and connected to the negative pressure source 131 to be applied to the liquid crystal tank 107. A negative pressure regulator 124 for adjusting the pressure to be connected is connected.

  Here, the positive pressure source 130 uses air that has been compressed and dried to remove foreign matters, or one kind of inert gas such as compressed nitrogen, helium, or neon. Further, when the liquid crystal tank 107 is not set to a positive pressure, the positive pressure source or the positive pressure regulator may not be used, and the liquid crystal tank 107 may be communicated with the atmosphere.

Under the control of the main controller 17 and the dispenser controller 18, the motors 3m, 4am, 4bm, and 6m are moved based on the data input from the keyboard 20 and stored in the RAM of the microcomputer 17a. ·Rotate. As a result, the nozzle 109 (FIG. 2) moves an arbitrary distance in the X and Y axis directions with respect to the substrate 7 held by the substrate holding mechanism 5 (FIG. 1), and the piston 102 moves during the movement. As a result, the liquid crystal agent is discharged from the discharge port at the tip of the nozzle 109, and a desired paste pattern is applied to the substrate 7.

  FIG. 5 shows a flowchart of the operation of the apparatus in this embodiment.

  In FIG. 5, first, power is turned on (step 100). Next, initial setting of the liquid crystal supply device is executed (step 200). In this initial setting step, processing for filling the microsyringe with a required amount of liquid crystal agent, setting of liquid crystal agent supply data, and the like are performed.

  A flowchart of the liquid crystal filling operation in the initial setting step is shown in FIG. In the liquid crystal filling operation, first, the atmospheric pressure in the liquid crystal tank 107 is set to atmospheric pressure or positive pressure (step 201). After confirming that the atmospheric pressure in the liquid crystal tank 107 has become an atmospheric pressure or a positive pressure by a pressure sensor (not shown), suction is performed to connect the suction side and the microsyringe 101 by driving the flow path switching valve by the R-axis motor 103M. Move to port position. (Step 202). Next, the Z axis is driven to move the piston 102, and the liquid crystal agent is allowed to flow into the microsyringe (step 203). In this process, when the piston 102 is moved from the direction of the flow path switching valve 103 (top dead center direction) to the opposite direction (bottom dead center direction), the inside of the microsyringe becomes negative pressure so that the liquid crystal agent 120 is liquid crystal tank. The operation of sucking in from 107 is performed. In the present embodiment, by making the pressure in the liquid crystal tank 107 positive in advance, the liquid crystal agent in the tank can be easily sent to the microsyringe side, so that the liquid crystal agent can be sent in response to the operation of the piston. It is possible to suppress air from being mixed into the agent.

When the inflow of the necessary amount is completed, the flow path switching valve is driven again by the R-axis motor 103M and moved to the discharge port position where the discharge side and the microsyringe 101 are communicated (step 204). Subsequently, the pressure in the liquid crystal tank is set to a vacuum (negative pressure) (step 205), and the liquid crystal filling operation is terminated (step 206). The degree of vacuum of the liquid crystal tank may be a low vacuum of about 10 ⁴ to 10 ³ Pa. Finally, the inside of the liquid crystal tank is set to a negative pressure to prevent the dissolution of air in the liquid crystal agent in the tank and prevent the drop accuracy from dropping.

  When the liquid crystal agent is supplied to the microsyringe, if the moving speed of the piston is too high relative to the inflow rate of the liquid crystal, air slightly dissolved in the liquid crystal agent escapes and bubbles are generated, resulting in bubble accumulation. These bubbles act as cushions and cause a decrease in the supply accuracy of the liquid crystal agent. For this reason, supply is smoothly performed by positively applying pressure in the liquid crystal tank. Further, in order to suppress the generation of bubbles in the moving speed of the piston, the positive pressure applied to the liquid crystal bottle and the moving speed of the piston may be determined in advance by a preparation test.

  Further, the nozzle 109 (FIG. 2) is set to a predetermined origin position so that the liquid crystal discharge port becomes a position at which liquid crystal supply starts (that is, a liquid crystal supply start point). Further, liquid crystal supply position data, substrate position data, and liquid crystal supply end position data are set.

  Here, an example of liquid crystal supply path data is shown in FIG. This is an example in which six liquid crystal panels are taken from one substrate. Reference numeral 50 denotes a glass substrate, 51 denotes a region which is divided into liquid crystal panels, 52 denotes a liquid crystal agent to be supplied, 53 denotes a supply operation path, and 54 dotted lines indicate movement paths between the liquid crystal panels. A desired liquid crystal agent is supplied to each liquid crystal panel area in the order of the liquid crystal panel areas 51A, 51B, 51C, 51D, 51E, and 51F. Here, in one liquid crystal panel area, the optimum liquid crystal supply amount is set according to the panel specifications based on the target screen size and the design value of the cell gap. For example, in a 20 inch diagonal liquid crystal panel, about 700 mg is set. The liquid crystal agent supply amount is set, and in this example, 4200 mg of the liquid crystal agent is filled in order to fill 6 surfaces at a time.

  The data is input from the keyboard 20 (FIG. 1), and the input data is stored in the RAM built in the microcomputer 17 (FIG. 3) as described above. When this initial setting step (step 200) is completed, the substrate 7 is then mounted and held on the substrate suction mechanism 5 (FIG. 1) (step 300). Subsequently, a substrate preliminary positioning process (step 400) is performed. In this process, the positioning mark of the substrate 7 mounted on the substrate holding mechanism 5 is photographed by the image recognition camera 15, the center of gravity of the positioning mark is obtained by image processing, and the inclination of the substrate 7 in the θ direction is detected. In response to this, the servo motor 6m (FIG. 3) is driven to correct the inclination in the θ direction. Thus, the substrate preliminary positioning process (step 400) is completed.

Next, a liquid crystal dropping process (step 500) is performed.
Linear motors 3m, 4am, and 4bm are driven based on path data (hereinafter referred to as drip path data) that smoothly connects the liquid crystal dropping positions stored in the RAM of the microcomputer 17a, thereby discharging the tip of the nozzle 109. With the outlet facing the substrate 7, it moves in the X and Y directions, and the piston 102 is intermittently moved according to the moving position, and intermittent discharge of liquid crystal from the discharge port at the tip of the nozzle 109 is started. Thereby, the liquid crystal dropping operation onto the substrate 7 is started.

  As described above, the microcomputer 18a of the dispenser control unit 18 inputs a supply signal generated from the position data of the nozzle 109 in the X and Y directions from the main control unit 17 and inputs a desired signal set in advance from the main control unit. The liquid crystal agent can be supplied at a supply amount of.

  The liquid crystal dropping operation is continued until the liquid crystal dropping reaches the end of the dropping path data and a desired liquid crystal is dropped on the substrate. When the end of the dropping path data is reached, the liquid crystal dropping process (step 500) ends.

  Next, the process proceeds to a substrate discharge process (step 600), the holding of the substrate 7 is released, and the substrate is discharged out of the apparatus. Then, it is determined whether or not to stop all the above processes (step 700). When liquid crystal is dropped on a plurality of substrates in the same pattern, the substrate mounting process (step 300) is repeated, and all the substrates are When such a series of processes is completed, all the operations are completed (step 800).

  As described above, in this embodiment, the dropping of the liquid crystal agent in which air is easily dissolved and high-precision dropping is required has been described, but not limited to the liquid crystal agent, any material can be used as long as it can be dropped.

  Moreover, although the dripping method is described, the drawing method may be performed by operating the syringe continuously instead of intermittently.

  As described above, according to the present invention, liquid crystal panel productivity can be improved because the liquid crystal agent can be dropped and supplied to the substrate accurately and stably without mixing bubbles.

It is a figure which shows the whole structure of a liquid crystal dropping apparatus. It is a figure which shows the supply flow path structure of a liquid crystal agent. It is a block diagram of functional arrangement | positioning of a main controller. It is a block diagram of functional arrangement of a sub-control device. It is a figure which shows the flowchart which shows the procedure of liquid crystal dropping. It is a figure which shows the flowchart explaining the liquid-crystal supply procedure in a micro syringe. It is the figure which showed the procedure of dripping a liquid crystal agent on a board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stand, 2a, 2b ... Y-axis moving mechanism support stand, 3 ... X-axis moving mechanism support stand, 4a, 4b ... Y-axis moving mechanism, 5 ... Substrate holding mechanism, 6 ... θ-axis moving table, 7 ... Substrate, DESCRIPTION OF SYMBOLS 8 ... Dispenser support bracket, 9 ... Liquid crystal dispenser, 101 ... Micro syringe, 102 ... Piston, 103 ... Switching valve, 105 ... Joint, 107 ... Liquid crystal tank, 108 ... Nozzle, 121 ... Solenoid valve, 122 ... Filter.

Claims (3)

A nozzle for dropping the liquid crystal agent from the discharge port facing the substrate placed on the table, a liquid crystal tank in which the liquid crystal agent supplied to the substrate is stored, and the liquid crystal agent in the liquid crystal tank is metered and filled, A microsyringe that performs quantitative dropping from a nozzle, and by dropping the liquid crystal agent filled in the microsyringe from the discharge port onto the substrate by changing the relative positional relationship between the substrate and the nozzle, In a liquid crystal dropping device that supplies a desired amount of liquid crystal agent to a desired position on the substrate,
The liquid crystal tank includes a positive pressure source that changes the pressure inside the liquid crystal atmosphere to atmospheric pressure or a positive pressure, and a negative pressure source that changes the pressure inside the liquid crystal tank to a vacuum atmosphere, and the defoaming treatment in the liquid crystal tank is performed. When the required amount of liquid crystal agent is filled in the microsyringe, the positive pressure source is connected to the liquid crystal tank, and the required amount of the liquid crystal agent filled in the microsyringe is supplied to the nozzle. in the step of dropping on the substrate, a liquid crystal dropping device, characterized in that a solenoid valve for connecting the negative pressure source to the liquid crystal reservoir. The liquid crystal dropping apparatus according to claim 1,
A liquid crystal dropping device comprising: a flow path switching unit that switches a flow path for supplying a liquid crystal agent from the liquid crystal tank to the microsyringe and a flow path for supplying the liquid crystal agent from the microsyringe to the nozzle. In the liquid crystal dropping device according to claim 1 or 2,
The microsyringe includes a piston, defines an amount of liquid crystal agent to be filled with a driving amount for driving the piston, and determines a moving speed of the piston according to a positive pressure applied to the liquid crystal tank. Liquid crystal dripping device.

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