JP3823050B2 - Paste applicator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a paste pattern is applied and drawn in the atmosphere in the clean environment of a clean room in a seal coating process in the production of LCD in a conventional coater but the particles or fine air bubbles generated from a slide part or the like are involved in the interface between the surface of a substrate plate and paste during the coating of the paste pattern. <P>SOLUTION: In this paste coater, a nozzle holding means for holding the substrate plate to a means for holding the coating surface of the substrate plate so as to turn the same downwardly and positioning the discharge orifice of a nozzle so as to oppose the same to the coating surface, a plunger extrusion type paste discharge means, a means for adjusting the interval between the tip of the nozzle and the coating surface of the substrate plate and a means for changing the relative positional relation of the substrate plate and the nozzle within the plane parallel to the coating surface of the substrate plate are housed in a vacuum chamber. <P>COPYRIGHT: (C)2003,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paste coating machine that draws a paste pattern of a desired shape on a substrate.
[0002]
[Prior art]
In a conventional paste applicator, as shown in Japanese Patent Laid-Open No. 11-262712, a tail portion that can be positioned by placing a substrate on which a paste is applied is provided on a gantry, and can be moved vertically or horizontally on the tail portion. A paste storage cylinder is provided to draw a desired paste pattern on the substrate. Conventionally, this paste applicator is installed in a clean room with little dust to apply paste.
[0003]
[Problems to be solved by the invention]
As described above, according to the conventional technology, in the seal coating process in the manufacture of LCD, the paste pattern is applied and drawn in the clean environment of the clean room. There is a problem that the grains are caught in the interface between the substrate surface and the paste during application of the paste pattern.
[0004]
An object of the present invention is to provide a paste applicator that solves the above-described problems and can stabilize the application and drawing of a paste pattern without involving foreign matter or minute air particles at the interface between the paste and the substrate surface.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention holds a substrate on a means for holding the coating surface of the substrate facing downward, and a nozzle holding means for positioning a nozzle discharge hole so as to face the coating surface and a plunger push-out type A paste applicator which accommodates in the vacuum chamber the paste discharge means, the distance between the nozzle tip and the substrate application surface, and the means for changing the relative positional relationship between the substrate and the nozzle in a plane parallel to the substrate application surface; To do.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, problems in applying a seal pattern for an LCD panel at high speed will be described.
In order to improve the coating tact, it is necessary to increase the moving speed of the substrate. In this regard, investigation of problems related to coating was advanced with fluid analysis software. When the substrate or nozzle was moved at high speed, air was entrained and stabilized when the paste discharged from the nozzle was transferred to the substrate surface. A phenomenon that could not be applied occurred.
[0007]
Thus, it is necessary to prevent the atmosphere from being involved when the sealing agent is discharged from the nozzle and applied to the surface of the substrate. Therefore, in the present invention, the sealing agent is applied in a vacuum. An apparatus for applying the paste in this vacuum will be described below.
[0008]
FIG. 1 is a perspective view showing an embodiment of a paste applicator according to the present invention.
In the figure, fixed support frames 2 a and 2 b including a Y-axis moving mechanism are fixed on a gantry 1. A movable support frame 3 is attached between the fixed support frames 2a and 2b, and is provided on the lower surface of the upper frame of the fixed support frames 2a and 2b formed in a gate shape on both ends of the movable frame 3. Y-axis moving linear motors 2a-m and 2b-m for moving along the guide rails are provided. Further, a linear motor 3m constituting an X-axis moving mechanism is attached to the movable support frame 3. The X-axis moving mechanism is further provided with a Z-axis moving mechanism 6. Further, a substrate holding table 12 having a substrate holding mechanism is provided on the upper surface side of the upper frames of the fixed support frames 2a and 2b.
[0009]
The substrate 4 is carried into the lower surface side of the substrate holding table 12 by a substrate moving hand or the like (not shown), and when it is carried into a predetermined position, the suction suction mechanism constituting a part of the substrate holding mechanism is operated. Adsorbed by suction. Note that the substrate holding mechanism of this embodiment includes an electrostatic chucking mechanism in addition to the suction chucking mechanism. Further, although not shown, assuming that the substrate has dropped from the substrate holding mechanism at the time of decompression, a substrate receiver that can project to the substrate side at the time of decompression is provided in the vicinity of the substrate holding table 12. In the present embodiment, the substrate is held so that the application surface of the substrate faces downward (towards the direction of gravity). With this configuration, falling dust is prevented from adhering to the substrate coating surface.
[0010]
An upper cover 1a for forming a vacuum chamber is provided so as to cover the fixed support frame 2a, the movable support frame 3a, the X-axis moving mechanism 3, the substrate holding table 12, and the like. The vacuum chamber is composed of the above-described upper cover 1a and the upper surface of the gantry 1 (lower vacuum chamber). The upper surface of the gantry 1 is provided with a plurality of suction ports 5a to 5f for sucking and depressurizing the gas in the chamber. These suction ports 5a to 5f communicate with a duct provided on the lower surface side of the gantry 1. In addition, one end side of the duct is closed, and a vacuum exhaust port 5 is provided on the other end side. The vacuum exhaust port 5 is connected to a vacuum pump or a decompression source not shown. As described above, by providing the suction ports 5a to 5F on the gantry surface located below the substrate holding table 12 in the gravity direction, dust in the chamber collects on the gantry surface side and is sucked from the suction port. Therefore, it is possible to prevent the dust in the chamber from decreasing and adhering to the substrate surface.
[0011]
Further, as shown in FIG. 5, the upper cover 1 a is provided with a gate valve 13 that also serves as a door for taking in and out the substrate 4. This gate valve is slightly wider than the maximum width of the substrate to be coated, and the height direction is at least high enough for the substrate and the substrate moving hand to enter when the substrate is taken in and out. In this embodiment, the gate valve 13 is opened and closed by a servo motor. However, the gate valve 13 may be opened and closed by an air cylinder.
[0012]
The Z-axis moving mechanism 6 is provided with a paste storage cylinder 7 and a nozzle 8 constituting a paste discharging mechanism, and further provided with a distance meter 8a and an image recognition camera with an illumination mechanism (not shown). The paste storage cylinder 7 is detachably attached to a movable part of a linear guide (not shown). The image recognition camera is provided so as to face the substrate in order to align the substrate and recognize the shape of the paste pattern.
[0013]
Furthermore, a control unit 9 for controlling each of the above mechanisms (linear motors 2a-m, 2b-m, 3m), a camera, and the like is provided at the lower portion of the gantry 1. The control unit 9 is connected to an operation panel 11 such as a keyboard and a monitor 10 by wiring 9a. Data used for various processes of the control unit 9 is input from the operation panel 11, and the processing status in the control unit 9 is displayed on the monitor 10. Data input from the operation panel 11 is stored and stored in a storage medium such as a hard disk or a floppy disk, which is an external storage device included in the control unit.
[0014]
The substrate holding mechanism 3 provided on the substrate holding table 12 is equipped with the vacuum suction mechanism and the electrostatic suction mechanism as described above. When the substrate is loaded, the substrate holding mechanism 3 is vacuum-sucked, and discharge is performed while monitoring the vacuum state after vacuum suction. A voltage is applied to the electrostatic chuck so that it does not occur, and the substrate is held. However, it is not necessary to reduce the pressure in the vacuum chamber so much, and if the suction force for attracting the substrate can be increased, the electrostatic attraction mechanism becomes unnecessary.
[0015]
FIG. 2 is an enlarged perspective view showing the paste discharge mechanism unit 7, the distance meter 8a, and the nozzle 8 in FIG. 1, and parts corresponding to those in FIG.
[0016]
In the figure, the distance meter 8a is provided with a light emitting element and a plurality of light receiving elements. The nozzle 8 is positioned above the distance meter 8a via a nozzle support 8b containing a paste conduit.
[0017]
The distance meter 8a measures the distance from the tip of the nozzle 8 to the paste application surface (lower surface) of the glass substrate 9 by non-contact triangulation. That is, the laser light 8L emitted from the light emitting element is reflected at the measurement point S on the surface of the substrate 4 and received by the light receiving element, and the height can be calculated. Therefore, the laser beam 8L is not blocked by the nozzle 8.
[0018]
Further, the measurement point S of the laser beam 8L on the surface of the substrate 4 and the position immediately below the nozzle 8 are shifted by a slight distance ΔX, ΔY on the substrate 4, but if the deviation is about this slight distance ΔX, ΔY, the substrate 4 Therefore, there is almost no difference between the measurement result of the distance meter 8 a and the distance from the tip of the nozzle 8 to the surface of the substrate 4.
[0019]
Therefore, by controlling the motor 6m for the Z-axis moving mechanism 6 based on the measurement result of the distance meter 8a, from the tip of the nozzle 8 to the surface of the substrate 4 according to the unevenness (swell) of the surface of the substrate 4 The distance (interval) can be kept constant.
[0020]
In this way, the distance (interval) from the tip of the nozzle 8 to the surface of the substrate 4 is kept constant, and the amount of paste discharged from the nozzle 8 per unit time is kept constant, The paste pattern applied and drawn on the substrate 4 has a uniform width and thickness.
[0021]
Further, the paste filled in the syringe of the paste storage cylinder 7 is sent to the nozzle 8 through the conduit of the nozzle support 8b through the pipe 7c by moving the piston 7a through the rod 7b. It is applied from the discharge hole. The piston 7a (rod 7b) is moved (controlled) in the axial direction by electric control so that the coating amount becomes constant.
[0022]
Next, the control method in a present Example is demonstrated.
Although not shown, the main control unit 9 incorporates a microcomputer, a motor controller, an XY-axis linear motor, a Z-axis servo motor driver, a discharge mechanism control unit, and an external interface for inputting the distance meter 8a. ing.
[0023]
Although not shown in the microcomputer, a ROM that stores a main calculation unit and a processing program for performing coating drawing, which will be described later, a RAM that stores processing results in the main calculation unit and input data from an external interface and a motor controller. , It has an input / output unit that exchanges data with an external interface and motor controller.
[0024]
The linear motor for XY axis and the servo motor for Z axis are provided with encoders for detecting the amount of movement and the amount of rotation, and the detection result is returned to each axis driver for position control. The XY axis linear motor and the Z axis servo motor move or forward / reversely rotate based on the data input from the operation panel 11 and stored in the RAM of the microcomputer, whereby the substrate holding mechanism 12 (FIG. 3). The supported nozzle 8 is moved by an arbitrary distance in the X and Y axis directions with respect to the substrate 4 held by the Z axis moving table 6, and the paste discharging mechanism is operated during the movement, so that the nozzle 8 The paste is continuously discharged from the discharge port at the tip of the substrate, and a desired paste pattern is applied and drawn on the application surface of the substrate 4. The distance meter 8a measures the distance between the nozzle 8 and the substrate 4 while the nozzle 8 is horizontally moved in the XY-axis direction with respect to the held substrate 4, and Z is maintained so as to always maintain a constant distance. The axis movement table 6 is controlled.
[0025]
Further, the movement speed and movement amount of the piston 7a are controlled by the command from the main control section 9, and the air pressure for applying the paste, the pressure reduction in the vacuum chamber, and the suction / adsorption control of the substrate are performed. In this embodiment, the substrate is held on the upper side and the paste is applied upward so that dust or the like does not fall on the substrate surface as much as possible. Further, by providing a suction port for decompression in the vacuum chamber on the surface of the gantry 1, there is also an effect of cleaning the inside of the vacuum chamber by sucking dust falling on the surface of the gantry from the suction port.
[0026]
Next, the operation of the apparatus in this embodiment will be described using the flowchart shown in FIG.
In FIG. 4, when the power is turned on (step 100), initial setting of the coating machine is first executed (step 200). In this initial setting step, the linear motors 2a-m, 2b shown in FIG. -M, 3m and servo motor 6m are driven to move the nozzle 8 in the X and Y directions to be positioned at a predetermined reference position, and the nozzle 8 is positioned at the position where the paste discharge port starts paste application (ie The paste application start point) is set at a predetermined origin position, and further, paste pattern data, substrate position data, and paste discharge end position data are set.
[0027]
The input of such data is performed from the operation panel 11, and the input data is stored in the RAM of the microcomputer built in the control unit 9 as described above. When this initial setting step (step 200) is completed, the substrate 4 is then mounted and held on the substrate holding mechanism 12 (step 300).
[0028]
Next, paste pattern drawing processing (step 400) is performed.
Before performing this processing, although not shown, it is necessary to capture the mark formed on the substrate with a CCD camera or the like, and to perform image processing to measure the displacement amount (dx, dy, dθ) mounted on the substrate. For example, the correction in the θ-axis direction of the substrate or the inclination of the X-axis movement of the nozzle is corrected to match the inclination of the substrate.
[0029]
In this process, the nozzle 8 is moved in order to position the discharge port of the nozzle 8 at the application start position, and the nozzle position is adjusted and moved based on the amount of thread obtained by the image processing as described above.
[0030]
Next, the servo motor 6m is operated to set the height of the nozzle 8 to the paste pattern drawing height. The nozzle 8 is raised by the initial moving distance based on the initial moving distance data of the nozzle. In the subsequent operation, the height of the coated surface (lower surface) of the substrate 4 is measured by the distance meter 8a, and it is confirmed whether or not the tip of the nozzle 8 is set to the height at which the paste pattern is drawn, and can be set to the drawing height. If not, the nozzle 8 is raised by a minute distance, the above-described measurement of the surface of the substrate 4 and the minute distance rise of the nozzle 8 are repeated, and the tip of the nozzle 8 is set to a height at which a paste pattern is applied and drawn.
When the above processing is completed, the linear motors 2a-m, 2b-m, and 3m are then driven based on the paste pattern data stored in the microcomputer RAM of the control unit 9. Thus, in a state where the paste discharge port of the nozzle 8 faces upward with respect to the substrate 4, the nozzle 8 moves in the X and Y directions according to the paste pattern data, and the paste discharge mechanism is operated to operate the nozzle 8. The discharge of the paste from the paste discharge port is started. Thereby, application drawing of the paste pattern on the substrate 4 starts. Along with this, as described above, the microcomputer of the control unit 9 inputs the actual measurement data of the distance between the paste discharge port of the nozzle 8 and the surface of the substrate 4 from the distance meter 8a, and the surface of the substrate 4 (the lower surface). ) And the Z-axis table 6 is driven in accordance with the measured value, so that the set interval of the nozzle 8 tip from the surface of the substrate 4 is maintained constant.
[0031]
The paste pattern is drawn as described above. By the way, during drawing, it is determined whether or not the paste discharge port of the nozzle 8 is the end of the drawing pattern determined by the paste pattern data on the substrate 4 application surface. If this determination result is not the termination, the process returns to the measurement process of the surface undulation of the substrate again, and the above coating drawing is repeated thereafter. When the judgment result reaches the end of the paste turn, the linear motors 2a-m, 2b-m, 3m and the Z-axis table 6 are driven to lower the nozzle 8 and wait, and this paste pattern drawing step (step 400) is performed. finish.
[0032]
Next, the process proceeds to the substrate discharge process (step 500), the inside of the vacuum chamber is returned to the atmospheric pressure, and the substrate moving hand is inserted into the vacuum chamber and set at a position where the substrate can be received. Is released and discharged out of the device.
[0033]
Then, it is determined whether or not to stop all the above processes (step 600). When the paste film is formed in the same pattern on a plurality of substrates, the process is repeated from the substrate mounting process (step 300). When such a series of processes for the substrate is completed, all the operations are completed (step 700).
[0034]
As described above, in the present invention, the paste pattern is drawn in a reduced pressure state, so that the dust does not rise so much that the substrate is faced downward and the paste is applied upward. Adhesion is almost eliminated, and a paste pattern can be stably drawn with no foreign matter mixed in the paste and no entrainment of minute air particles. In addition, when applying under reduced pressure in this way, the application is performed with the substrate facing downward, but even if the substrate is faced upward as in the conventional case, the application is performed in a reduced pressure state as compared with the conventional case. Mixing of dust and entrainment of minute air particles can be reduced.
[0035]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a paste applicator capable of stabilizing the application and drawing of a paste pattern without involving foreign matter or minute air particles at the interface between the paste and the substrate surface.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a paste applicator according to the present invention.
FIG. 2 is a perspective view for explaining a coating head unit in the embodiment shown in FIG.
FIG. 3 is a perspective view for explaining a substrate holding mechanism in the embodiment shown in FIG. 1;
FIG. 4 is a flowchart for explaining the operation of the apparatus in the embodiment shown in FIG. 1;
FIG. 5 is a view showing a substrate loading / unloading section provided in a vacuum chamber section.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base, 2a, 2b ... Y-axis moving mechanism support frame, 3 ... X-axis moving mechanism, 4 ... Board | substrate, 5 ... Vacuum pump connection port, 5a-5f ... Vacuum exhaust port, 6 ... Z-axis moving mechanism, 6m ... z axis drive motor, 7 ... syringe (paste storage cylinder), 7a ... piston, 7b ... piston rod, 7c ... piping, 8 ... nozzle, 8a ... distance meter, 8b ... nozzle support, 9 ... control unit, 9a ... connection Cable, 10 ... monitor, 11 ... operation panel, 12 ... substrate holding mechanism.

Claims (1)

A substrate holding table having a substrate holding mechanism for holding the substrate; a paste applying mechanism for applying a paste to the substrate; the paste applying mechanism having a nozzle having a discharge port so as to face the substrate; In a paste applicator comprising a paste storage cylinder storing paste discharged from an outlet, interval adjusting means for adjusting the interval between the substrate and the nozzle, and a drive mechanism for changing the relative positional relationship between the substrate and the nozzle ,
The substrate holding table and the paste application mechanism are housed in a vacuum chamber, the substrate holding table is provided so as to face a pedestal surface constituting a part of the vacuum chamber, and a duct provided on the back surface of the gantry A plurality of suction ports are provided on the pedestal surface so as to communicate with each other, the inside of the vacuum chamber is decompressed by a decompression source connected to the duct, the substrate holding table holds the substrate with the coating surface facing down, and the paste The applicator includes nozzle holding means for positioning the discharge hole of the nozzle and plunger push-type paste discharge means in the paste storage cylinder, and applies the paste in a predetermined reduced pressure state in the vacuum chamber. And paste applicator.

Images